[PATCH 0/7] Network namespace manipulation with file descriptors

[PATCH 0/7] Network namespace manipulation with file descriptors

[Eric W. Biederman]

Today there are something things you can use namespaces to implement but
the userspace code is unnecessarily complex and fragile because of
limitations of the kernel interfaces.

This patchset addresses the user interface limitations by introducing
proc files you can open to get file descriptors that keep alive and
refer to your a tasks namespaces.  Those file descriptors can be passed
to the new setns system call or the NET_NS_FD argument in netlink
messages.

This patchset is sufficient to implement linux support for named network
namespaces in iproute allowing vpns to be isolated in a network
namespace where you don't have to worry about them conflicting with the
rest of your network.

This patchset is almost sufficient to remove the need for a daemon in a
container to allow you to log in.  Unfortunately a few of the namespaces
are not ready to merge yet so I have left them out.

Arch maintainers could you look over patch 7 and verify I have wired
up this new system call correctly.

These changes are also available at:
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/linux-2.6-nsfd.git

[PATCH 0/7] Network namespace manipulation with file descriptors

[Eric W. Biederman]

Today there are something things you can use namespaces to implement but
the userspace code is unnecessarily complex and fragile because of
limitations of the kernel interfaces.

This patchset addresses the user interface limitations by introducing
proc files you can open to get file descriptors that keep alive and
refer to your a tasks namespaces.  Those file descriptors can be passed
to the new setns system call or the NET_NS_FD argument in netlink
messages.

This patchset is sufficient to implement linux support for named network
namespaces in iproute allowing vpns to be isolated in a network
namespace where you don't have to worry about them conflicting with the
rest of your network.

This patchset is almost sufficient to remove the need for a daemon in a
container to allow you to log in.  Unfortunately a few of the namespaces
are not ready to merge yet so I have left them out.

Arch maintainers could you look over patch 7 and verify I have wired
up this new system call correctly.

These changes are also available at:
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/linux-2.6-nsfd.git

[PATCH 1/7] ns: proc files for namespace naming policy.

[Eric W. Biederman]

Create files under /proc/<pid>/ns/ to allow controlling the
namespaces of a process.

This addresses three specific problems that can make namespaces hard to
work with.
- Namespaces require a dedicated process to pin them in memory.
- It is not possible to use a namespace unless you are the child
  of the original creator.
- Namespaces don't have names that userspace can use to talk about
  them.

The namespace files under /proc/<pid>/ns/ can be opened and the
file descriptor can be used to talk about a specific namespace, and
to keep the specified namespace alive.

A namespace can be kept alive by either holding the file descriptor
open or bind mounting the file someplace else.  aka:
mount --bind /proc/self/ns/net /some/filesystem/path
mount --bind /proc/self/fd/<N> /some/filesystem/path

This allows namespaces to be named with userspace policy.

It requires additional support to make use of these filedescriptors
and that will be comming in the following patches.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 fs/proc/Makefile        |    1 +
 fs/proc/base.c          |   20 ++---
 fs/proc/inode.c         |    7 ++
 fs/proc/internal.h      |   18 +++++
 fs/proc/namespaces.c    |  188 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/proc_fs.h |   18 +++++
 6 files changed, 241 insertions(+), 11 deletions(-)
 create mode 100644 fs/proc/namespaces.c

diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index df434c5..c1c7293 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -20,6 +20,7 @@ proc-y	+= stat.o
 proc-y	+= uptime.o
 proc-y	+= version.o
 proc-y	+= softirqs.o
+proc-y	+= namespaces.o
 proc-$(CONFIG_PROC_SYSCTL)	+= proc_sysctl.o
 proc-$(CONFIG_NET)		+= proc_net.o
 proc-$(CONFIG_PROC_KCORE)	+= kcore.o
diff --git a/fs/proc/base.c b/fs/proc/base.c
index dfa5327..dc8bca7 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -600,7 +600,7 @@ static int proc_fd_access_allowed(struct inode *inode)
 	return allowed;
 }
 
-static int proc_setattr(struct dentry *dentry, struct iattr *attr)
+int proc_setattr(struct dentry *dentry, struct iattr *attr)
 {
 	int error;
 	struct inode *inode = dentry->d_inode;
@@ -1736,8 +1736,7 @@ static int task_dumpable(struct task_struct *task)
 	return 0;
 }
 
-
-static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
+struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
 {
 	struct inode * inode;
 	struct proc_inode *ei;
@@ -1779,7 +1778,7 @@ out_unlock:
 	return NULL;
 }
 
-static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 {
 	struct inode *inode = dentry->d_inode;
 	struct task_struct *task;
@@ -1820,7 +1819,7 @@ static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat
  * made this apply to all per process world readable and executable
  * directories.
  */
-static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
+int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
 	struct inode *inode;
 	struct task_struct *task;
@@ -1862,7 +1861,7 @@ static int pid_delete_dentry(const struct dentry * dentry)
 	return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
 }
 
-static const struct dentry_operations pid_dentry_operations =
+const struct dentry_operations pid_dentry_operations =
 {
 	.d_revalidate	= pid_revalidate,
 	.d_delete	= pid_delete_dentry,
@@ -1870,9 +1869,6 @@ static const struct dentry_operations pid_dentry_operations =
 
 /* Lookups */
 
-typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
-				struct task_struct *, const void *);
-
 /*
  * Fill a directory entry.
  *
@@ -1885,8 +1881,8 @@ typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
  * reported by readdir in sync with the inode numbers reported
  * by stat.
  */
-static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
-	char *name, int len,
+int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
+	const char *name, int len,
 	instantiate_t instantiate, struct task_struct *task, const void *ptr)
 {
 	struct dentry *child, *dir = filp->f_path.dentry;
@@ -2820,6 +2816,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 	DIR("task",       S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
 	DIR("fd",         S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
 	DIR("fdinfo",     S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
+	DIR("ns",	  S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
 #ifdef CONFIG_NET
 	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
 #endif
@@ -3168,6 +3165,7 @@ out_no_task:
 static const struct pid_entry tid_base_stuff[] = {
 	DIR("fd",        S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
 	DIR("fdinfo",    S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
+	DIR("ns",	 S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
 	REG("environ",   S_IRUSR, proc_environ_operations),
 	INF("auxv",      S_IRUSR, proc_pid_auxv),
 	ONE("status",    S_IRUGO, proc_pid_status),
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index d15aa1b..74b48cf 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -28,6 +28,7 @@ static void proc_evict_inode(struct inode *inode)
 {
 	struct proc_dir_entry *de;
 	struct ctl_table_header *head;
+	const struct proc_ns_operations *ns_ops;
 
 	truncate_inode_pages(&inode->i_data, 0);
 	end_writeback(inode);
@@ -44,6 +45,10 @@ static void proc_evict_inode(struct inode *inode)
 		rcu_assign_pointer(PROC_I(inode)->sysctl, NULL);
 		sysctl_head_put(head);
 	}
+	/* Release any associated namespace */
+	ns_ops = PROC_I(inode)->ns_ops;
+	if (ns_ops && ns_ops->put)
+		ns_ops->put(PROC_I(inode)->ns);
 }
 
 static struct kmem_cache * proc_inode_cachep;
@@ -62,6 +67,8 @@ static struct inode *proc_alloc_inode(struct super_block *sb)
 	ei->pde = NULL;
 	ei->sysctl = NULL;
 	ei->sysctl_entry = NULL;
+	ei->ns = NULL;
+	ei->ns_ops = NULL;
 	inode = &ei->vfs_inode;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
 	return inode;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index c03e8d3..96245a1 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -119,3 +119,21 @@ struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
  */
 int proc_readdir(struct file *, void *, filldir_t);
 struct dentry *proc_lookup(struct inode *, struct dentry *, struct nameidata *);
+
+
+
+/* Lookups */
+typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
+				struct task_struct *, const void *);
+int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
+	const char *name, int len,
+	instantiate_t instantiate, struct task_struct *task, const void *ptr);
+int pid_revalidate(struct dentry *dentry, struct nameidata *nd);
+struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task);
+extern const struct dentry_operations pid_dentry_operations;
+int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
+int proc_setattr(struct dentry *dentry, struct iattr *attr);
+
+extern const struct inode_operations proc_ns_dir_inode_operations;
+extern const struct file_operations proc_ns_dir_operations;
+
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
new file mode 100644
index 0000000..6ae9f07
--- /dev/null
+++ b/fs/proc/namespaces.c
@@ -0,0 +1,188 @@
+#include <linux/proc_fs.h>
+#include <linux/nsproxy.h>
+#include <linux/sched.h>
+#include <linux/ptrace.h>
+#include <linux/fs_struct.h>
+#include <linux/mount.h>
+#include <linux/path.h>
+#include <linux/namei.h>
+#include <linux/file.h>
+#include <linux/utsname.h>
+#include <net/net_namespace.h>
+#include <linux/mnt_namespace.h>
+#include <linux/ipc_namespace.h>
+#include <linux/pid_namespace.h>
+#include "internal.h"
+
+
+static const struct proc_ns_operations *ns_entries[] = {
+};
+
+static const struct file_operations ns_file_operations = {
+	.llseek		= no_llseek,
+};
+
+static struct dentry *proc_ns_instantiate(struct inode *dir,
+	struct dentry *dentry, struct task_struct *task, const void *ptr)
+{
+	const struct proc_ns_operations *ns_ops = ptr;
+	struct inode *inode;
+	struct proc_inode *ei;
+	struct dentry *error = ERR_PTR(-ENOENT);
+
+	inode = proc_pid_make_inode(dir->i_sb, task);
+	if (!inode)
+		goto out;
+
+	ei = PROC_I(inode);
+	inode->i_mode = S_IFREG|S_IRUSR;
+	inode->i_fop  = &ns_file_operations;
+	ei->ns_ops    = ns_ops;
+	ei->ns	      = ns_ops->get(task);
+	if (!ei->ns)
+		goto out_iput;
+
+	dentry->d_op = &pid_dentry_operations;
+	d_add(dentry, inode);
+	/* Close the race of the process dying before we return the dentry */
+	if (pid_revalidate(dentry, NULL))
+		error = NULL;
+out:
+	return error;
+out_iput:
+	iput(inode);
+	goto out;
+}
+
+static int proc_ns_fill_cache(struct file *filp, void *dirent,
+	filldir_t filldir, struct task_struct *task,
+	const struct proc_ns_operations *ops)
+{
+	return proc_fill_cache(filp, dirent, filldir,
+				ops->name, strlen(ops->name),
+				proc_ns_instantiate, task, ops);
+}
+
+static int proc_ns_dir_readdir(struct file *filp, void *dirent,
+				filldir_t filldir)
+{
+	int i;
+	struct dentry *dentry = filp->f_path.dentry;
+	struct inode *inode = dentry->d_inode;
+	struct task_struct *task = get_proc_task(inode);
+	const struct proc_ns_operations **entry, **last;
+	ino_t ino;
+	int ret;
+
+	ret = -ENOENT;
+	if (!task)
+		goto out_no_task;
+
+	ret = -EPERM;
+	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+		goto out;
+
+	ret = 0;
+	i = filp->f_pos;
+	switch (i) {
+	case 0:
+		ino = inode->i_ino;
+		if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
+			goto out;
+		i++;
+		filp->f_pos++;
+		/* fall through */
+	case 1:
+		ino = parent_ino(dentry);
+		if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
+			goto out;
+		i++;
+		filp->f_pos++;
+		/* fall through */
+	default:
+		i -= 2;
+		if (i >= ARRAY_SIZE(ns_entries)) {
+			ret = 1;
+			goto out;
+		}
+		entry = ns_entries + i;
+		last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
+		while (entry <= last) {
+			if (proc_ns_fill_cache(filp, dirent, filldir,
+						task, *entry) < 0)
+				goto out;
+			filp->f_pos++;
+			entry++;
+		}
+	}
+
+	ret = 1;
+out:
+	put_task_struct(task);
+out_no_task:
+	return ret;
+}
+
+const struct file_operations proc_ns_dir_operations = {
+	.read		= generic_read_dir,
+	.readdir	= proc_ns_dir_readdir,
+};
+
+static struct dentry *proc_ns_dir_lookup(struct inode *dir,
+				struct dentry *dentry, struct nameidata *nd)
+{
+	struct dentry *error;
+	struct task_struct *task = get_proc_task(dir);
+	const struct proc_ns_operations **entry, **last;
+	unsigned int len = dentry->d_name.len;
+
+	error = ERR_PTR(-ENOENT);
+
+	if (!task)
+		goto out_no_task;
+
+	error = ERR_PTR(-EPERM);
+	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+		goto out;
+
+	last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
+	for (entry = ns_entries; entry <= last; entry++) {
+		if (strlen((*entry)->name) != len)
+			continue;
+		if (!memcmp(dentry->d_name.name, (*entry)->name, len))
+			break;
+	}
+	if (entry > last)
+		goto out;
+
+	error = proc_ns_instantiate(dir, dentry, task, *entry);
+out:
+	put_task_struct(task);
+out_no_task:
+	return error;
+}
+
+const struct inode_operations proc_ns_dir_inode_operations = {
+	.lookup		= proc_ns_dir_lookup,
+	.getattr	= pid_getattr,
+	.setattr	= proc_setattr,
+};
+
+struct file *proc_ns_fget(int fd)
+{
+	struct file *file;
+
+	file = fget(fd);
+	if (!file)
+		return ERR_PTR(-EBADF);
+
+	if (file->f_op != &ns_file_operations)
+		goto out_invalid;
+
+	return file;
+
+out_invalid:
+	fput(file);
+	return ERR_PTR(-EINVAL);
+}
+
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 838c114..a6d2c6d 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -179,6 +179,8 @@ extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
 extern struct file *get_mm_exe_file(struct mm_struct *mm);
 extern void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm);
 
+extern struct file *proc_ns_fget(int fd);
+
 #else
 
 #define proc_net_fops_create(net, name, mode, fops)  ({ (void)(mode), NULL; })
@@ -239,6 +241,11 @@ static inline void dup_mm_exe_file(struct mm_struct *oldmm,
 	       			   struct mm_struct *newmm)
 {}
 
+static inline struct file *proc_ns_fget(int fd)
+{
+	return ERR_PTR(-EINVAL);
+}
+
 #endif /* CONFIG_PROC_FS */
 
 #if !defined(CONFIG_PROC_KCORE)
@@ -250,6 +257,15 @@ kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
 extern void kclist_add(struct kcore_list *, void *, size_t, int type);
 #endif
 
+struct nsproxy;
+struct proc_ns_operations {
+	const char *name;
+	int type;
+	void *(*get)(struct task_struct *task);
+	void (*put)(void *ns);
+	int (*install)(struct nsproxy *nsproxy, void *ns);
+};
+
 union proc_op {
 	int (*proc_get_link)(struct inode *, struct path *);
 	int (*proc_read)(struct task_struct *task, char *page);
@@ -268,6 +284,8 @@ struct proc_inode {
 	struct proc_dir_entry *pde;
 	struct ctl_table_header *sysctl;
 	struct ctl_table *sysctl_entry;
+	void *ns;
+	const struct proc_ns_operations *ns_ops;
 	struct inode vfs_inode;
 };
 
-- 
1.6.5.2.143.g8cc62

[PATCH 1/7] ns: proc files for namespace naming policy.

[Eric W. Biederman]

Create files under /proc/<pid>/ns/ to allow controlling the
namespaces of a process.

This addresses three specific problems that can make namespaces hard to
work with.
- Namespaces require a dedicated process to pin them in memory.
- It is not possible to use a namespace unless you are the child
  of the original creator.
- Namespaces don't have names that userspace can use to talk about
  them.

The namespace files under /proc/<pid>/ns/ can be opened and the
file descriptor can be used to talk about a specific namespace, and
to keep the specified namespace alive.

A namespace can be kept alive by either holding the file descriptor
open or bind mounting the file someplace else.  aka:
mount --bind /proc/self/ns/net /some/filesystem/path
mount --bind /proc/self/fd/<N> /some/filesystem/path

This allows namespaces to be named with userspace policy.

It requires additional support to make use of these filedescriptors
and that will be comming in the following patches.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 fs/proc/Makefile        |    1 +
 fs/proc/base.c          |   20 ++---
 fs/proc/inode.c         |    7 ++
 fs/proc/internal.h      |   18 +++++
 fs/proc/namespaces.c    |  188 +++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/proc_fs.h |   18 +++++
 6 files changed, 241 insertions(+), 11 deletions(-)
 create mode 100644 fs/proc/namespaces.c

diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index df434c5..c1c7293 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -20,6 +20,7 @@ proc-y	+= stat.o
 proc-y	+= uptime.o
 proc-y	+= version.o
 proc-y	+= softirqs.o
+proc-y	+= namespaces.o
 proc-$(CONFIG_PROC_SYSCTL)	+= proc_sysctl.o
 proc-$(CONFIG_NET)		+= proc_net.o
 proc-$(CONFIG_PROC_KCORE)	+= kcore.o
diff --git a/fs/proc/base.c b/fs/proc/base.c
index dfa5327..dc8bca7 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -600,7 +600,7 @@ static int proc_fd_access_allowed(struct inode *inode)
 	return allowed;
 }
 
-static int proc_setattr(struct dentry *dentry, struct iattr *attr)
+int proc_setattr(struct dentry *dentry, struct iattr *attr)
 {
 	int error;
 	struct inode *inode = dentry->d_inode;
@@ -1736,8 +1736,7 @@ static int task_dumpable(struct task_struct *task)
 	return 0;
 }
 
-
-static struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
+struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task)
 {
 	struct inode * inode;
 	struct proc_inode *ei;
@@ -1779,7 +1778,7 @@ out_unlock:
 	return NULL;
 }
 
-static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 {
 	struct inode *inode = dentry->d_inode;
 	struct task_struct *task;
@@ -1820,7 +1819,7 @@ static int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat
  * made this apply to all per process world readable and executable
  * directories.
  */
-static int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
+int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
 	struct inode *inode;
 	struct task_struct *task;
@@ -1862,7 +1861,7 @@ static int pid_delete_dentry(const struct dentry * dentry)
 	return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first;
 }
 
-static const struct dentry_operations pid_dentry_operations =
+const struct dentry_operations pid_dentry_operations =
 {
 	.d_revalidate	= pid_revalidate,
 	.d_delete	= pid_delete_dentry,
@@ -1870,9 +1869,6 @@ static const struct dentry_operations pid_dentry_operations =
 
 /* Lookups */
 
-typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
-				struct task_struct *, const void *);
-
 /*
  * Fill a directory entry.
  *
@@ -1885,8 +1881,8 @@ typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
  * reported by readdir in sync with the inode numbers reported
  * by stat.
  */
-static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
-	char *name, int len,
+int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
+	const char *name, int len,
 	instantiate_t instantiate, struct task_struct *task, const void *ptr)
 {
 	struct dentry *child, *dir = filp->f_path.dentry;
@@ -2820,6 +2816,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 	DIR("task",       S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
 	DIR("fd",         S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
 	DIR("fdinfo",     S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
+	DIR("ns",	  S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
 #ifdef CONFIG_NET
 	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
 #endif
@@ -3168,6 +3165,7 @@ out_no_task:
 static const struct pid_entry tid_base_stuff[] = {
 	DIR("fd",        S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
 	DIR("fdinfo",    S_IRUSR|S_IXUSR, proc_fdinfo_inode_operations, proc_fdinfo_operations),
+	DIR("ns",	 S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
 	REG("environ",   S_IRUSR, proc_environ_operations),
 	INF("auxv",      S_IRUSR, proc_pid_auxv),
 	ONE("status",    S_IRUGO, proc_pid_status),
diff --git a/fs/proc/inode.c b/fs/proc/inode.c
index d15aa1b..74b48cf 100644
--- a/fs/proc/inode.c
+++ b/fs/proc/inode.c
@@ -28,6 +28,7 @@ static void proc_evict_inode(struct inode *inode)
 {
 	struct proc_dir_entry *de;
 	struct ctl_table_header *head;
+	const struct proc_ns_operations *ns_ops;
 
 	truncate_inode_pages(&inode->i_data, 0);
 	end_writeback(inode);
@@ -44,6 +45,10 @@ static void proc_evict_inode(struct inode *inode)
 		rcu_assign_pointer(PROC_I(inode)->sysctl, NULL);
 		sysctl_head_put(head);
 	}
+	/* Release any associated namespace */
+	ns_ops = PROC_I(inode)->ns_ops;
+	if (ns_ops && ns_ops->put)
+		ns_ops->put(PROC_I(inode)->ns);
 }
 
 static struct kmem_cache * proc_inode_cachep;
@@ -62,6 +67,8 @@ static struct inode *proc_alloc_inode(struct super_block *sb)
 	ei->pde = NULL;
 	ei->sysctl = NULL;
 	ei->sysctl_entry = NULL;
+	ei->ns = NULL;
+	ei->ns_ops = NULL;
 	inode = &ei->vfs_inode;
 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
 	return inode;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index c03e8d3..96245a1 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -119,3 +119,21 @@ struct inode *proc_get_inode(struct super_block *, struct proc_dir_entry *);
  */
 int proc_readdir(struct file *, void *, filldir_t);
 struct dentry *proc_lookup(struct inode *, struct dentry *, struct nameidata *);
+
+
+
+/* Lookups */
+typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
+				struct task_struct *, const void *);
+int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
+	const char *name, int len,
+	instantiate_t instantiate, struct task_struct *task, const void *ptr);
+int pid_revalidate(struct dentry *dentry, struct nameidata *nd);
+struct inode *proc_pid_make_inode(struct super_block * sb, struct task_struct *task);
+extern const struct dentry_operations pid_dentry_operations;
+int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat);
+int proc_setattr(struct dentry *dentry, struct iattr *attr);
+
+extern const struct inode_operations proc_ns_dir_inode_operations;
+extern const struct file_operations proc_ns_dir_operations;
+
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
new file mode 100644
index 0000000..6ae9f07
--- /dev/null
+++ b/fs/proc/namespaces.c
@@ -0,0 +1,188 @@
+#include <linux/proc_fs.h>
+#include <linux/nsproxy.h>
+#include <linux/sched.h>
+#include <linux/ptrace.h>
+#include <linux/fs_struct.h>
+#include <linux/mount.h>
+#include <linux/path.h>
+#include <linux/namei.h>
+#include <linux/file.h>
+#include <linux/utsname.h>
+#include <net/net_namespace.h>
+#include <linux/mnt_namespace.h>
+#include <linux/ipc_namespace.h>
+#include <linux/pid_namespace.h>
+#include "internal.h"
+
+
+static const struct proc_ns_operations *ns_entries[] = {
+};
+
+static const struct file_operations ns_file_operations = {
+	.llseek		= no_llseek,
+};
+
+static struct dentry *proc_ns_instantiate(struct inode *dir,
+	struct dentry *dentry, struct task_struct *task, const void *ptr)
+{
+	const struct proc_ns_operations *ns_ops = ptr;
+	struct inode *inode;
+	struct proc_inode *ei;
+	struct dentry *error = ERR_PTR(-ENOENT);
+
+	inode = proc_pid_make_inode(dir->i_sb, task);
+	if (!inode)
+		goto out;
+
+	ei = PROC_I(inode);
+	inode->i_mode = S_IFREG|S_IRUSR;
+	inode->i_fop  = &ns_file_operations;
+	ei->ns_ops    = ns_ops;
+	ei->ns	      = ns_ops->get(task);
+	if (!ei->ns)
+		goto out_iput;
+
+	dentry->d_op = &pid_dentry_operations;
+	d_add(dentry, inode);
+	/* Close the race of the process dying before we return the dentry */
+	if (pid_revalidate(dentry, NULL))
+		error = NULL;
+out:
+	return error;
+out_iput:
+	iput(inode);
+	goto out;
+}
+
+static int proc_ns_fill_cache(struct file *filp, void *dirent,
+	filldir_t filldir, struct task_struct *task,
+	const struct proc_ns_operations *ops)
+{
+	return proc_fill_cache(filp, dirent, filldir,
+				ops->name, strlen(ops->name),
+				proc_ns_instantiate, task, ops);
+}
+
+static int proc_ns_dir_readdir(struct file *filp, void *dirent,
+				filldir_t filldir)
+{
+	int i;
+	struct dentry *dentry = filp->f_path.dentry;
+	struct inode *inode = dentry->d_inode;
+	struct task_struct *task = get_proc_task(inode);
+	const struct proc_ns_operations **entry, **last;
+	ino_t ino;
+	int ret;
+
+	ret = -ENOENT;
+	if (!task)
+		goto out_no_task;
+
+	ret = -EPERM;
+	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+		goto out;
+
+	ret = 0;
+	i = filp->f_pos;
+	switch (i) {
+	case 0:
+		ino = inode->i_ino;
+		if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
+			goto out;
+		i++;
+		filp->f_pos++;
+		/* fall through */
+	case 1:
+		ino = parent_ino(dentry);
+		if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0)
+			goto out;
+		i++;
+		filp->f_pos++;
+		/* fall through */
+	default:
+		i -= 2;
+		if (i >= ARRAY_SIZE(ns_entries)) {
+			ret = 1;
+			goto out;
+		}
+		entry = ns_entries + i;
+		last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
+		while (entry <= last) {
+			if (proc_ns_fill_cache(filp, dirent, filldir,
+						task, *entry) < 0)
+				goto out;
+			filp->f_pos++;
+			entry++;
+		}
+	}
+
+	ret = 1;
+out:
+	put_task_struct(task);
+out_no_task:
+	return ret;
+}
+
+const struct file_operations proc_ns_dir_operations = {
+	.read		= generic_read_dir,
+	.readdir	= proc_ns_dir_readdir,
+};
+
+static struct dentry *proc_ns_dir_lookup(struct inode *dir,
+				struct dentry *dentry, struct nameidata *nd)
+{
+	struct dentry *error;
+	struct task_struct *task = get_proc_task(dir);
+	const struct proc_ns_operations **entry, **last;
+	unsigned int len = dentry->d_name.len;
+
+	error = ERR_PTR(-ENOENT);
+
+	if (!task)
+		goto out_no_task;
+
+	error = ERR_PTR(-EPERM);
+	if (!ptrace_may_access(task, PTRACE_MODE_READ))
+		goto out;
+
+	last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
+	for (entry = ns_entries; entry <= last; entry++) {
+		if (strlen((*entry)->name) != len)
+			continue;
+		if (!memcmp(dentry->d_name.name, (*entry)->name, len))
+			break;
+	}
+	if (entry > last)
+		goto out;
+
+	error = proc_ns_instantiate(dir, dentry, task, *entry);
+out:
+	put_task_struct(task);
+out_no_task:
+	return error;
+}
+
+const struct inode_operations proc_ns_dir_inode_operations = {
+	.lookup		= proc_ns_dir_lookup,
+	.getattr	= pid_getattr,
+	.setattr	= proc_setattr,
+};
+
+struct file *proc_ns_fget(int fd)
+{
+	struct file *file;
+
+	file = fget(fd);
+	if (!file)
+		return ERR_PTR(-EBADF);
+
+	if (file->f_op != &ns_file_operations)
+		goto out_invalid;
+
+	return file;
+
+out_invalid:
+	fput(file);
+	return ERR_PTR(-EINVAL);
+}
+
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 838c114..a6d2c6d 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -179,6 +179,8 @@ extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
 extern struct file *get_mm_exe_file(struct mm_struct *mm);
 extern void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm);
 
+extern struct file *proc_ns_fget(int fd);
+
 #else
 
 #define proc_net_fops_create(net, name, mode, fops)  ({ (void)(mode), NULL; })
@@ -239,6 +241,11 @@ static inline void dup_mm_exe_file(struct mm_struct *oldmm,
 	       			   struct mm_struct *newmm)
 {}
 
+static inline struct file *proc_ns_fget(int fd)
+{
+	return ERR_PTR(-EINVAL);
+}
+
 #endif /* CONFIG_PROC_FS */
 
 #if !defined(CONFIG_PROC_KCORE)
@@ -250,6 +257,15 @@ kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
 extern void kclist_add(struct kcore_list *, void *, size_t, int type);
 #endif
 
+struct nsproxy;
+struct proc_ns_operations {
+	const char *name;
+	int type;
+	void *(*get)(struct task_struct *task);
+	void (*put)(void *ns);
+	int (*install)(struct nsproxy *nsproxy, void *ns);
+};
+
 union proc_op {
 	int (*proc_get_link)(struct inode *, struct path *);
 	int (*proc_read)(struct task_struct *task, char *page);
@@ -268,6 +284,8 @@ struct proc_inode {
 	struct proc_dir_entry *pde;
 	struct ctl_table_header *sysctl;
 	struct ctl_table *sysctl_entry;
+	void *ns;
+	const struct proc_ns_operations *ns_ops;
 	struct inode vfs_inode;
 };
 
-- 
1.6.5.2.143.g8cc62

[PATCH 2/7] ns: Introduce the setns syscall

[Eric W. Biederman]

With the networking stack today there is demand to handle
multiple network stacks at a time.  Not in the context
of containers but in the context of people doing interesting
things with routing.

There is also demand in the context of containers to have
an efficient way to execute some code in the container itself.
If nothing else it is very useful ad a debugging technique.

Both problems can be solved by starting some form of login
daemon in the namespaces people want access to, or you
can play games by ptracing a process and getting the
traced process to do things you want it to do. However
it turns out that a login daemon or a ptrace puppet
controller are more code, they are more prone to
failure, and generally they are less efficient than
simply changing the namespace of a process to a
specified one.

Pieces of this puzzle can also be solved by instead of
coming up with a general purpose system call coming up
with targed system calls perhaps socketat that solve
a subset of the larger problem.  Overall that appears
to be more work for less reward.

int setns(int fd, int nstype);

The fd argument is a file descriptor referring to a proc
file of the namespace you want to switch the process to.

In the setns system call the nstype is 0 or specifies
an clone flag of the namespace you intend to change
to prevent changing a namespace unintentionally.

v2: Most of the architecture support added by Daniel Lezcano <dlezcano-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>
v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
v4: Moved wiring up of the system call to another patch

Signed-off-by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
---
 kernel/nsproxy.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index a05d191..96059d8 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -22,6 +22,9 @@
 #include <linux/pid_namespace.h>
 #include <net/net_namespace.h>
 #include <linux/ipc_namespace.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
+#include <linux/syscalls.h>
 
 static struct kmem_cache *nsproxy_cachep;
 
@@ -233,6 +236,40 @@ void exit_task_namespaces(struct task_struct *p)
 	switch_task_namespaces(p, NULL);
 }
 
+SYSCALL_DEFINE2(setns, int, fd, int, nstype)
+{
+	const struct proc_ns_operations *ops;
+	struct task_struct *tsk = current;
+	struct nsproxy *new_nsproxy;
+	struct proc_inode *ei;
+	struct file *file;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	file = proc_ns_fget(fd);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	err = -EINVAL;
+	ei = PROC_I(file->f_dentry->d_inode);
+	ops = ei->ns_ops;
+	if (nstype && (ops->type != nstype))
+		goto out;
+
+	new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);
+	err = ops->install(new_nsproxy, ei->ns);
+	if (err) {
+		free_nsproxy(new_nsproxy);
+		goto out;
+	}
+	switch_task_namespaces(tsk, new_nsproxy);
+out:
+	fput(file);
+	return err;
+}
+
 static int __init nsproxy_cache_init(void)
 {
 	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
-- 
1.6.5.2.143.g8cc62

[PATCH 2/7] ns: Introduce the setns syscall

[Eric W. Biederman]

With the networking stack today there is demand to handle
multiple network stacks at a time.  Not in the context
of containers but in the context of people doing interesting
things with routing.

There is also demand in the context of containers to have
an efficient way to execute some code in the container itself.
If nothing else it is very useful ad a debugging technique.

Both problems can be solved by starting some form of login
daemon in the namespaces people want access to, or you
can play games by ptracing a process and getting the
traced process to do things you want it to do. However
it turns out that a login daemon or a ptrace puppet
controller are more code, they are more prone to
failure, and generally they are less efficient than
simply changing the namespace of a process to a
specified one.

Pieces of this puzzle can also be solved by instead of
coming up with a general purpose system call coming up
with targed system calls perhaps socketat that solve
a subset of the larger problem.  Overall that appears
to be more work for less reward.

int setns(int fd, int nstype);

The fd argument is a file descriptor referring to a proc
file of the namespace you want to switch the process to.

In the setns system call the nstype is 0 or specifies
an clone flag of the namespace you intend to change
to prevent changing a namespace unintentionally.

v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
v4: Moved wiring up of the system call to another patch

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 kernel/nsproxy.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index a05d191..96059d8 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -22,6 +22,9 @@
 #include <linux/pid_namespace.h>
 #include <net/net_namespace.h>
 #include <linux/ipc_namespace.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
+#include <linux/syscalls.h>
 
 static struct kmem_cache *nsproxy_cachep;
 
@@ -233,6 +236,40 @@ void exit_task_namespaces(struct task_struct *p)
 	switch_task_namespaces(p, NULL);
 }
 
+SYSCALL_DEFINE2(setns, int, fd, int, nstype)
+{
+	const struct proc_ns_operations *ops;
+	struct task_struct *tsk = current;
+	struct nsproxy *new_nsproxy;
+	struct proc_inode *ei;
+	struct file *file;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	file = proc_ns_fget(fd);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	err = -EINVAL;
+	ei = PROC_I(file->f_dentry->d_inode);
+	ops = ei->ns_ops;
+	if (nstype && (ops->type != nstype))
+		goto out;
+
+	new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);
+	err = ops->install(new_nsproxy, ei->ns);
+	if (err) {
+		free_nsproxy(new_nsproxy);
+		goto out;
+	}
+	switch_task_namespaces(tsk, new_nsproxy);
+out:
+	fput(file);
+	return err;
+}
+
 static int __init nsproxy_cache_init(void)
 {
 	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
-- 
1.6.5.2.143.g8cc62

[PATCH 2/7] ns: Introduce the setns syscall

[Eric W. Biederman]

With the networking stack today there is demand to handle
multiple network stacks at a time.  Not in the context
of containers but in the context of people doing interesting
things with routing.

There is also demand in the context of containers to have
an efficient way to execute some code in the container itself.
If nothing else it is very useful ad a debugging technique.

Both problems can be solved by starting some form of login
daemon in the namespaces people want access to, or you
can play games by ptracing a process and getting the
traced process to do things you want it to do. However
it turns out that a login daemon or a ptrace puppet
controller are more code, they are more prone to
failure, and generally they are less efficient than
simply changing the namespace of a process to a
specified one.

Pieces of this puzzle can also be solved by instead of
coming up with a general purpose system call coming up
with targed system calls perhaps socketat that solve
a subset of the larger problem.  Overall that appears
to be more work for less reward.

int setns(int fd, int nstype);

The fd argument is a file descriptor referring to a proc
file of the namespace you want to switch the process to.

In the setns system call the nstype is 0 or specifies
an clone flag of the namespace you intend to change
to prevent changing a namespace unintentionally.

v2: Most of the architecture support added by Daniel Lezcano <dlezcano-NmTC/0ZBporQT0dZR+AlfA@public.gmane.org>
v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
v4: Moved wiring up of the system call to another patch

Signed-off-by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
---
 kernel/nsproxy.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index a05d191..96059d8 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -22,6 +22,9 @@
 #include <linux/pid_namespace.h>
 #include <net/net_namespace.h>
 #include <linux/ipc_namespace.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
+#include <linux/syscalls.h>
 
 static struct kmem_cache *nsproxy_cachep;
 
@@ -233,6 +236,40 @@ void exit_task_namespaces(struct task_struct *p)
 	switch_task_namespaces(p, NULL);
 }
 
+SYSCALL_DEFINE2(setns, int, fd, int, nstype)
+{
+	const struct proc_ns_operations *ops;
+	struct task_struct *tsk = current;
+	struct nsproxy *new_nsproxy;
+	struct proc_inode *ei;
+	struct file *file;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	file = proc_ns_fget(fd);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	err = -EINVAL;
+	ei = PROC_I(file->f_dentry->d_inode);
+	ops = ei->ns_ops;
+	if (nstype && (ops->type != nstype))
+		goto out;
+
+	new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);
+	err = ops->install(new_nsproxy, ei->ns);
+	if (err) {
+		free_nsproxy(new_nsproxy);
+		goto out;
+	}
+	switch_task_namespaces(tsk, new_nsproxy);
+out:
+	fput(file);
+	return err;
+}
+
 static int __init nsproxy_cache_init(void)
 {
 	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
-- 
1.6.5.2.143.g8cc62

[PATCH 2/7] ns: Introduce the setns syscall

[Eric W. Biederman]

With the networking stack today there is demand to handle
multiple network stacks at a time.  Not in the context
of containers but in the context of people doing interesting
things with routing.

There is also demand in the context of containers to have
an efficient way to execute some code in the container itself.
If nothing else it is very useful ad a debugging technique.

Both problems can be solved by starting some form of login
daemon in the namespaces people want access to, or you
can play games by ptracing a process and getting the
traced process to do things you want it to do. However
it turns out that a login daemon or a ptrace puppet
controller are more code, they are more prone to
failure, and generally they are less efficient than
simply changing the namespace of a process to a
specified one.

Pieces of this puzzle can also be solved by instead of
coming up with a general purpose system call coming up
with targed system calls perhaps socketat that solve
a subset of the larger problem.  Overall that appears
to be more work for less reward.

int setns(int fd, int nstype);

The fd argument is a file descriptor referring to a proc
file of the namespace you want to switch the process to.

In the setns system call the nstype is 0 or specifies
an clone flag of the namespace you intend to change
to prevent changing a namespace unintentionally.

v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
v4: Moved wiring up of the system call to another patch

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 kernel/nsproxy.c |   37 +++++++++++++++++++++++++++++++++++++
 1 files changed, 37 insertions(+), 0 deletions(-)

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index a05d191..96059d8 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -22,6 +22,9 @@
 #include <linux/pid_namespace.h>
 #include <net/net_namespace.h>
 #include <linux/ipc_namespace.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
+#include <linux/syscalls.h>
 
 static struct kmem_cache *nsproxy_cachep;
 
@@ -233,6 +236,40 @@ void exit_task_namespaces(struct task_struct *p)
 	switch_task_namespaces(p, NULL);
 }
 
+SYSCALL_DEFINE2(setns, int, fd, int, nstype)
+{
+	const struct proc_ns_operations *ops;
+	struct task_struct *tsk = current;
+	struct nsproxy *new_nsproxy;
+	struct proc_inode *ei;
+	struct file *file;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	file = proc_ns_fget(fd);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	err = -EINVAL;
+	ei = PROC_I(file->f_dentry->d_inode);
+	ops = ei->ns_ops;
+	if (nstype && (ops->type != nstype))
+		goto out;
+
+	new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);
+	err = ops->install(new_nsproxy, ei->ns);
+	if (err) {
+		free_nsproxy(new_nsproxy);
+		goto out;
+	}
+	switch_task_namespaces(tsk, new_nsproxy);
+out:
+	fput(file);
+	return err;
+}
+
 static int __init nsproxy_cache_init(void)
 {
 	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
-- 
1.6.5.2.143.g8cc62

Re: [PATCH 2/7] ns: Introduce the setns syscall

[Rémi Denis-Courmont]

Le samedi 7 mai 2011 05:24:56 Eric W. Biederman, vous avez écrit :
> Pieces of this puzzle can also be solved by instead of
> coming up with a general purpose system call coming up
> with targed system calls perhaps socketat that solve
> a subset of the larger problem.  Overall that appears
> to be more work for less reward.

socketat() is still required for multithreaded namespace-aware userspace, I 
believe.

-- 
Rémi Denis-Courmont
http://www.remlab.info/
http://fi.linkedin.com/in/remidenis

Re: [PATCH 2/7] ns: Introduce the setns syscall

[Rémi Denis-Courmont]

Le samedi 7 mai 2011 05:24:56 Eric W. Biederman, vous avez écrit :
> Pieces of this puzzle can also be solved by instead of
> coming up with a general purpose system call coming up
> with targed system calls perhaps socketat that solve
> a subset of the larger problem.  Overall that appears
> to be more work for less reward.

socketat() is still required for multithreaded namespace-aware userspace, I 
believe.

-- 
Rémi Denis-Courmont
http://www.remlab.info/
http://fi.linkedin.com/in/remidenis

Re: [PATCH 2/7] ns: Introduce the setns syscall

[Eric W. Biederman]

"Rémi Denis-Courmont" <remi@remlab.net> writes:

> Le samedi 7 mai 2011 05:24:56 Eric W. Biederman, vous avez écrit :
>> Pieces of this puzzle can also be solved by instead of
>> coming up with a general purpose system call coming up
>> with targed system calls perhaps socketat that solve
>> a subset of the larger problem.  Overall that appears
>> to be more work for less reward.
>
> socketat() is still required for multithreaded namespace-aware userspace, I 
> believe.

The network namespace is a per task property so there are no problems
with multithreaded network namespace aware userspace applications.  The
implementation of a userspace socketat will still need to disable signal
handling around the network namespace switch to be signal safe.  Which
means that ultimately a kernel version of socketat may be desirable,
for performance reasons but I know of know correctness reasons to need
it.

For the time being I have simply removed socketat from what I plan to
merge because it is not strictly needed, I don't yet have a test case
for socketat, and I don't have as much time to work on this as I
would like.

There is one bug a multi-threaded network namespace aware user space
application might run into, and that is /proc/net is a symlink to
/proc/self.  Which means that if you open /proc/net/foo from a task with
a different network namespace than your the task whose tid equals your
tgid, the /proc/net will return the wrong file.  Still you can
avoid even that silliness by opening /proc/<tid>/net.

Eric
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Re: [PATCH 2/7] ns: Introduce the setns syscall

[Eric W. Biederman]

"Rémi Denis-Courmont" <remi@remlab.net> writes:

> Le samedi 7 mai 2011 05:24:56 Eric W. Biederman, vous avez écrit :
>> Pieces of this puzzle can also be solved by instead of
>> coming up with a general purpose system call coming up
>> with targed system calls perhaps socketat that solve
>> a subset of the larger problem.  Overall that appears
>> to be more work for less reward.
>
> socketat() is still required for multithreaded namespace-aware userspace, I 
> believe.

The network namespace is a per task property so there are no problems
with multithreaded network namespace aware userspace applications.  The
implementation of a userspace socketat will still need to disable signal
handling around the network namespace switch to be signal safe.  Which
means that ultimately a kernel version of socketat may be desirable,
for performance reasons but I know of know correctness reasons to need
it.

For the time being I have simply removed socketat from what I plan to
merge because it is not strictly needed, I don't yet have a test case
for socketat, and I don't have as much time to work on this as I
would like.

There is one bug a multi-threaded network namespace aware user space
application might run into, and that is /proc/net is a symlink to
/proc/self.  Which means that if you open /proc/net/foo from a task with
a different network namespace than your the task whose tid equals your
tgid, the /proc/net will return the wrong file.  Still you can
avoid even that silliness by opening /proc/<tid>/net.

Eric

Re: [PATCH 2/7] ns: Introduce the setns syscall

[Daniel Lezcano]

On 05/07/2011 04:24 AM, Eric W. Biederman wrote:
> With the networking stack today there is demand to handle
> multiple network stacks at a time.  Not in the context
> of containers but in the context of people doing interesting
> things with routing.
>
> There is also demand in the context of containers to have
> an efficient way to execute some code in the container itself.
> If nothing else it is very useful ad a debugging technique.
>
> Both problems can be solved by starting some form of login
> daemon in the namespaces people want access to, or you
> can play games by ptracing a process and getting the
> traced process to do things you want it to do. However
> it turns out that a login daemon or a ptrace puppet
> controller are more code, they are more prone to
> failure, and generally they are less efficient than
> simply changing the namespace of a process to a
> specified one.
>
> Pieces of this puzzle can also be solved by instead of
> coming up with a general purpose system call coming up
> with targed system calls perhaps socketat that solve
> a subset of the larger problem.  Overall that appears
> to be more work for less reward.
>
> int setns(int fd, int nstype);
>
> The fd argument is a file descriptor referring to a proc
> file of the namespace you want to switch the process to.
>
> In the setns system call the nstype is 0 or specifies
> an clone flag of the namespace you intend to change
> to prevent changing a namespace unintentionally.
>
> v2: Most of the architecture support added by Daniel Lezcano<dlezcano@fr.ibm.com>
> v3: ported to v2.6.36-rc4 by: Eric W. Biederman<ebiederm@xmission.com>
> v4: Moved wiring up of the system call to another patch
>
> Signed-off-by: Eric W. Biederman<ebiederm@xmission.com>
> ---

Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>

Re: [PATCH 2/7] ns: Introduce the setns syscall

[Matt Helsley]

On Fri, May 06, 2011 at 07:24:56PM -0700, Eric W. Biederman wrote:
> With the networking stack today there is demand to handle
> multiple network stacks at a time.  Not in the context
> of containers but in the context of people doing interesting
> things with routing.
> 
> There is also demand in the context of containers to have
> an efficient way to execute some code in the container itself.
> If nothing else it is very useful ad a debugging technique.
> 
> Both problems can be solved by starting some form of login
> daemon in the namespaces people want access to, or you
> can play games by ptracing a process and getting the
> traced process to do things you want it to do. However
> it turns out that a login daemon or a ptrace puppet
> controller are more code, they are more prone to
> failure, and generally they are less efficient than
> simply changing the namespace of a process to a
> specified one.
> 
> Pieces of this puzzle can also be solved by instead of
> coming up with a general purpose system call coming up
> with targed system calls perhaps socketat that solve
> a subset of the larger problem.  Overall that appears
> to be more work for less reward.
> 
> int setns(int fd, int nstype);
> 
> The fd argument is a file descriptor referring to a proc
> file of the namespace you want to switch the process to.
> 
> In the setns system call the nstype is 0 or specifies
> an clone flag of the namespace you intend to change
> to prevent changing a namespace unintentionally.
> 
> v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
> v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
> v4: Moved wiring up of the system call to another patch
> 
> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
> ---
>  kernel/nsproxy.c |   37 +++++++++++++++++++++++++++++++++++++
>  1 files changed, 37 insertions(+), 0 deletions(-)
> 
> diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
> index a05d191..96059d8 100644
> --- a/kernel/nsproxy.c
> +++ b/kernel/nsproxy.c
> @@ -22,6 +22,9 @@
>  #include <linux/pid_namespace.h>
>  #include <net/net_namespace.h>
>  #include <linux/ipc_namespace.h>
> +#include <linux/proc_fs.h>
> +#include <linux/file.h>
> +#include <linux/syscalls.h>
> 
>  static struct kmem_cache *nsproxy_cachep;
> 
> @@ -233,6 +236,40 @@ void exit_task_namespaces(struct task_struct *p)
>  	switch_task_namespaces(p, NULL);
>  }
> 
> +SYSCALL_DEFINE2(setns, int, fd, int, nstype)
> +{
> +	const struct proc_ns_operations *ops;
> +	struct task_struct *tsk = current;
> +	struct nsproxy *new_nsproxy;
> +	struct proc_inode *ei;
> +	struct file *file;
> +	int err;
> +
> +	if (!capable(CAP_SYS_ADMIN))
> +		return -EPERM;
> +
> +	file = proc_ns_fget(fd);
> +	if (IS_ERR(file))
> +		return PTR_ERR(file);
> +
> +	err = -EINVAL;
> +	ei = PROC_I(file->f_dentry->d_inode);
> +	ops = ei->ns_ops;
> +	if (nstype && (ops->type != nstype))
> +		goto out;
> +
> +	new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);

Doesn't this need some error checking like:

	if (IS_ERR(new_nsproxy)) {
		err = PTR_ERR(new_nsproxy);
		goto out;
	}


> +	err = ops->install(new_nsproxy, ei->ns);
> +	if (err) {
> +		free_nsproxy(new_nsproxy);
> +		goto out;
> +	}
> +	switch_task_namespaces(tsk, new_nsproxy);
> +out:
> +	fput(file);
> +	return err;
> +}
> +
>  static int __init nsproxy_cache_init(void)
>  {
>  	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
> -- 
> 1.6.5.2.143.g8cc62
> 
> _______________________________________________
> Containers mailing list
> Containers@lists.linux-foundation.org
> https://lists.linux-foundation.org/mailman/listinfo/containers

Re: [PATCH 2/7] ns: Introduce the setns syscall

[Nathan Lynch]

Hi Eric,

On Fri, 2011-05-06 at 19:24 -0700, Eric W. Biederman wrote:
> With the networking stack today there is demand to handle
> multiple network stacks at a time.  Not in the context
> of containers but in the context of people doing interesting
> things with routing.
> 
> There is also demand in the context of containers to have
> an efficient way to execute some code in the container itself.
> If nothing else it is very useful ad a debugging technique.
> 
> Both problems can be solved by starting some form of login
> daemon in the namespaces people want access to, or you
> can play games by ptracing a process and getting the
> traced process to do things you want it to do. However
> it turns out that a login daemon or a ptrace puppet
> controller are more code, they are more prone to
> failure, and generally they are less efficient than
> simply changing the namespace of a process to a
> specified one.
> 
> Pieces of this puzzle can also be solved by instead of
> coming up with a general purpose system call coming up
> with targed system calls perhaps socketat that solve
> a subset of the larger problem.  Overall that appears
> to be more work for less reward.
> 
> int setns(int fd, int nstype);
> 
> The fd argument is a file descriptor referring to a proc
> file of the namespace you want to switch the process to.
> 
> In the setns system call the nstype is 0 or specifies
> an clone flag of the namespace you intend to change
> to prevent changing a namespace unintentionally.

I don't understand exactly what the nstype argument buys us - why would
correct code ever need to specify a value other than 0?  And reusing the
CLONE_NEW* values in this interface is kind of ugly when setns is
precisely _not_ creating new namespaces.

Is there some fundamental reason it couldn't be

int setns(int fd);

or is there a use case I'm missing?

 
> +SYSCALL_DEFINE2(setns, int, fd, int, nstype)
> +{
> +	const struct proc_ns_operations *ops;
> +	struct task_struct *tsk = current;
> +	struct nsproxy *new_nsproxy;
> +	struct proc_inode *ei;
> +	struct file *file;
> +	int err;
> +
> +	if (!capable(CAP_SYS_ADMIN))
> +		return -EPERM;
> +
> +	file = proc_ns_fget(fd);
> +	if (IS_ERR(file))
> +		return PTR_ERR(file);
> +
> +	err = -EINVAL;
> +	ei = PROC_I(file->f_dentry->d_inode);
> +	ops = ei->ns_ops;
> +	if (nstype && (ops->type != nstype))
> +		goto out;
> +
> +	new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);

create_new_namespaces() can fail; shouldn't this be checked?


> +	err = ops->install(new_nsproxy, ei->ns);
> +	if (err) {
> +		free_nsproxy(new_nsproxy);
> +		goto out;
> +	}
> +	switch_task_namespaces(tsk, new_nsproxy);
> +out:
> +	fput(file);
> +	return err;
> +}
> +

Re: [PATCH 2/7] ns: Introduce the setns syscall

[Eric W. Biederman]

Nathan Lynch <ntl@pobox.com> writes:

> Hi Eric,
>
> On Fri, 2011-05-06 at 19:24 -0700, Eric W. Biederman wrote:
>> With the networking stack today there is demand to handle
>> multiple network stacks at a time.  Not in the context
>> of containers but in the context of people doing interesting
>> things with routing.
>> 
>> There is also demand in the context of containers to have
>> an efficient way to execute some code in the container itself.
>> If nothing else it is very useful ad a debugging technique.
>> 
>> Both problems can be solved by starting some form of login
>> daemon in the namespaces people want access to, or you
>> can play games by ptracing a process and getting the
>> traced process to do things you want it to do. However
>> it turns out that a login daemon or a ptrace puppet
>> controller are more code, they are more prone to
>> failure, and generally they are less efficient than
>> simply changing the namespace of a process to a
>> specified one.
>> 
>> Pieces of this puzzle can also be solved by instead of
>> coming up with a general purpose system call coming up
>> with targed system calls perhaps socketat that solve
>> a subset of the larger problem.  Overall that appears
>> to be more work for less reward.
>> 
>> int setns(int fd, int nstype);
>> 
>> The fd argument is a file descriptor referring to a proc
>> file of the namespace you want to switch the process to.
>> 
>> In the setns system call the nstype is 0 or specifies
>> an clone flag of the namespace you intend to change
>> to prevent changing a namespace unintentionally.
>
> I don't understand exactly what the nstype argument buys us - why would
> correct code ever need to specify a value other than 0?  And reusing the
> CLONE_NEW* values in this interface is kind of ugly when setns is
> precisely _not_ creating new namespaces.

No but it is setting a new namespace.  I do agree it is a bit ugly.  But
the worst case at this point is I introduce a new set of beautiful
defines with the same values.

> Is there some fundamental reason it couldn't be
>
> int setns(int fd);
>
> or is there a use case I'm missing?

When someone else opens the file descriptor and passes it to us
and we don't completely trust them.  Or equally when someone
else does the bind mount into the filesystem namespace and we
don't completely trust them.

Plus having a flags field is useful in general.

>> +SYSCALL_DEFINE2(setns, int, fd, int, nstype)
>> +{
>> +	const struct proc_ns_operations *ops;
>> +	struct task_struct *tsk = current;
>> +	struct nsproxy *new_nsproxy;
>> +	struct proc_inode *ei;
>> +	struct file *file;
>> +	int err;
>> +
>> +	if (!capable(CAP_SYS_ADMIN))
>> +		return -EPERM;
>> +
>> +	file = proc_ns_fget(fd);
>> +	if (IS_ERR(file))
>> +		return PTR_ERR(file);
>> +
>> +	err = -EINVAL;
>> +	ei = PROC_I(file->f_dentry->d_inode);
>> +	ops = ei->ns_ops;
>> +	if (nstype && (ops->type != nstype))
>> +		goto out;
>> +
>> +	new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);
>
> create_new_namespaces() can fail; shouldn't this be checked?

Yes.  This was pointed out a little earlier and has been fixed
in my tree.


>> +	err = ops->install(new_nsproxy, ei->ns);
>> +	if (err) {
>> +		free_nsproxy(new_nsproxy);
>> +		goto out;
>> +	}
>> +	switch_task_namespaces(tsk, new_nsproxy);
>> +out:
>> +	fput(file);
>> +	return err;
>> +}
>> +

Eric

[PATCH 6/7] net: Allow setting the network namespace by fd

[Eric W. Biederman]

Take advantage of the new abstraction and allow network devices
to be placed in any network namespace that we have a fd to talk
about.

Signed-off-by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
---
 include/linux/if_link.h     |    1 +
 include/net/net_namespace.h |    1 +
 net/core/net_namespace.c    |   33 +++++++++++++++++++++++++++++++--
 net/core/rtnetlink.c        |    5 ++++-
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index f4a2e6b..0ee969a 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -136,6 +136,7 @@ enum {
 	IFLA_PORT_SELF,
 	IFLA_AF_SPEC,
 	IFLA_GROUP,		/* Group the device belongs to */
+	IFLA_NET_NS_FD,
 	__IFLA_MAX
 };
 
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 3ae4919..dcc8f57 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -119,6 +119,7 @@ static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
 extern struct list_head net_namespace_list;
 
 extern struct net *get_net_ns_by_pid(pid_t pid);
+extern struct net *get_net_ns_by_fd(int pid);
 
 #ifdef CONFIG_NET_NS
 extern void __put_net(struct net *net);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index bf7707e..b7403ff 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -8,6 +8,8 @@
 #include <linux/idr.h>
 #include <linux/rculist.h>
 #include <linux/nsproxy.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -343,6 +345,28 @@ struct net *get_net_ns_by_pid(pid_t pid)
 }
 EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
 
+struct net *get_net_ns_by_fd(int fd)
+{
+	struct proc_inode *ei;
+	struct file *file;
+	struct net *net;
+
+	net = ERR_PTR(-EINVAL);
+	file = proc_ns_fget(fd);
+	if (!file)
+		goto out;
+
+	ei = PROC_I(file->f_dentry->d_inode);
+	if (ei->ns_ops != &netns_operations)
+		goto out;
+
+	net = get_net(ei->ns);
+out:
+	if (file)
+		fput(file);
+	return net;
+}
+
 static int __init net_ns_init(void)
 {
 	struct net_generic *ng;
@@ -577,10 +601,15 @@ EXPORT_SYMBOL_GPL(unregister_pernet_device);
 #ifdef CONFIG_NET_NS
 static void *netns_get(struct task_struct *task)
 {
-	struct net *net;
+	struct net *net = NULL;
+	struct nsproxy *nsproxy;
+
 	rcu_read_lock();
-	net = get_net(task->nsproxy->net_ns);
+	nsproxy = task_nsproxy(task);
+	if (nsproxy)
+		net = get_net(nsproxy->net_ns);
 	rcu_read_unlock();
+
 	return net;
 }
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index d7c4bb4..dca9602 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1043,6 +1043,7 @@ const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
 	[IFLA_LINKINFO]		= { .type = NLA_NESTED },
 	[IFLA_NET_NS_PID]	= { .type = NLA_U32 },
+	[IFLA_NET_NS_FD]	= { .type = NLA_U32 },
 	[IFLA_IFALIAS]	        = { .type = NLA_STRING, .len = IFALIASZ-1 },
 	[IFLA_VFINFO_LIST]	= {. type = NLA_NESTED },
 	[IFLA_VF_PORTS]		= { .type = NLA_NESTED },
@@ -1091,6 +1092,8 @@ struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[])
 	 */
 	if (tb[IFLA_NET_NS_PID])
 		net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
+	else if (tb[IFLA_NET_NS_FD])
+		net = get_net_ns_by_fd(nla_get_u32(tb[IFLA_NET_NS_FD]));
 	else
 		net = get_net(src_net);
 	return net;
@@ -1221,7 +1224,7 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
 	int send_addr_notify = 0;
 	int err;
 
-	if (tb[IFLA_NET_NS_PID]) {
+	if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD]) {
 		struct net *net = rtnl_link_get_net(dev_net(dev), tb);
 		if (IS_ERR(net)) {
 			err = PTR_ERR(net);
-- 
1.6.5.2.143.g8cc62

[PATCH 6/7] net: Allow setting the network namespace by fd

[Eric W. Biederman]

Take advantage of the new abstraction and allow network devices
to be placed in any network namespace that we have a fd to talk
about.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 include/linux/if_link.h     |    1 +
 include/net/net_namespace.h |    1 +
 net/core/net_namespace.c    |   33 +++++++++++++++++++++++++++++++--
 net/core/rtnetlink.c        |    5 ++++-
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index f4a2e6b..0ee969a 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -136,6 +136,7 @@ enum {
 	IFLA_PORT_SELF,
 	IFLA_AF_SPEC,
 	IFLA_GROUP,		/* Group the device belongs to */
+	IFLA_NET_NS_FD,
 	__IFLA_MAX
 };
 
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 3ae4919..dcc8f57 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -119,6 +119,7 @@ static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
 extern struct list_head net_namespace_list;
 
 extern struct net *get_net_ns_by_pid(pid_t pid);
+extern struct net *get_net_ns_by_fd(int pid);
 
 #ifdef CONFIG_NET_NS
 extern void __put_net(struct net *net);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index bf7707e..b7403ff 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -8,6 +8,8 @@
 #include <linux/idr.h>
 #include <linux/rculist.h>
 #include <linux/nsproxy.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -343,6 +345,28 @@ struct net *get_net_ns_by_pid(pid_t pid)
 }
 EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
 
+struct net *get_net_ns_by_fd(int fd)
+{
+	struct proc_inode *ei;
+	struct file *file;
+	struct net *net;
+
+	net = ERR_PTR(-EINVAL);
+	file = proc_ns_fget(fd);
+	if (!file)
+		goto out;
+
+	ei = PROC_I(file->f_dentry->d_inode);
+	if (ei->ns_ops != &netns_operations)
+		goto out;
+
+	net = get_net(ei->ns);
+out:
+	if (file)
+		fput(file);
+	return net;
+}
+
 static int __init net_ns_init(void)
 {
 	struct net_generic *ng;
@@ -577,10 +601,15 @@ EXPORT_SYMBOL_GPL(unregister_pernet_device);
 #ifdef CONFIG_NET_NS
 static void *netns_get(struct task_struct *task)
 {
-	struct net *net;
+	struct net *net = NULL;
+	struct nsproxy *nsproxy;
+
 	rcu_read_lock();
-	net = get_net(task->nsproxy->net_ns);
+	nsproxy = task_nsproxy(task);
+	if (nsproxy)
+		net = get_net(nsproxy->net_ns);
 	rcu_read_unlock();
+
 	return net;
 }
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index d7c4bb4..dca9602 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1043,6 +1043,7 @@ const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
 	[IFLA_LINKINFO]		= { .type = NLA_NESTED },
 	[IFLA_NET_NS_PID]	= { .type = NLA_U32 },
+	[IFLA_NET_NS_FD]	= { .type = NLA_U32 },
 	[IFLA_IFALIAS]	        = { .type = NLA_STRING, .len = IFALIASZ-1 },
 	[IFLA_VFINFO_LIST]	= {. type = NLA_NESTED },
 	[IFLA_VF_PORTS]		= { .type = NLA_NESTED },
@@ -1091,6 +1092,8 @@ struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[])
 	 */
 	if (tb[IFLA_NET_NS_PID])
 		net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
+	else if (tb[IFLA_NET_NS_FD])
+		net = get_net_ns_by_fd(nla_get_u32(tb[IFLA_NET_NS_FD]));
 	else
 		net = get_net(src_net);
 	return net;
@@ -1221,7 +1224,7 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
 	int send_addr_notify = 0;
 	int err;
 
-	if (tb[IFLA_NET_NS_PID]) {
+	if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD]) {
 		struct net *net = rtnl_link_get_net(dev_net(dev), tb);
 		if (IS_ERR(net)) {
 			err = PTR_ERR(net);
-- 
1.6.5.2.143.g8cc62

[PATCH 6/7] net: Allow setting the network namespace by fd

[Eric W. Biederman]

Take advantage of the new abstraction and allow network devices
to be placed in any network namespace that we have a fd to talk
about.

Signed-off-by: Eric W. Biederman <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
---
 include/linux/if_link.h     |    1 +
 include/net/net_namespace.h |    1 +
 net/core/net_namespace.c    |   33 +++++++++++++++++++++++++++++++--
 net/core/rtnetlink.c        |    5 ++++-
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index f4a2e6b..0ee969a 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -136,6 +136,7 @@ enum {
 	IFLA_PORT_SELF,
 	IFLA_AF_SPEC,
 	IFLA_GROUP,		/* Group the device belongs to */
+	IFLA_NET_NS_FD,
 	__IFLA_MAX
 };
 
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 3ae4919..dcc8f57 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -119,6 +119,7 @@ static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
 extern struct list_head net_namespace_list;
 
 extern struct net *get_net_ns_by_pid(pid_t pid);
+extern struct net *get_net_ns_by_fd(int pid);
 
 #ifdef CONFIG_NET_NS
 extern void __put_net(struct net *net);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index bf7707e..b7403ff 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -8,6 +8,8 @@
 #include <linux/idr.h>
 #include <linux/rculist.h>
 #include <linux/nsproxy.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -343,6 +345,28 @@ struct net *get_net_ns_by_pid(pid_t pid)
 }
 EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
 
+struct net *get_net_ns_by_fd(int fd)
+{
+	struct proc_inode *ei;
+	struct file *file;
+	struct net *net;
+
+	net = ERR_PTR(-EINVAL);
+	file = proc_ns_fget(fd);
+	if (!file)
+		goto out;
+
+	ei = PROC_I(file->f_dentry->d_inode);
+	if (ei->ns_ops != &netns_operations)
+		goto out;
+
+	net = get_net(ei->ns);
+out:
+	if (file)
+		fput(file);
+	return net;
+}
+
 static int __init net_ns_init(void)
 {
 	struct net_generic *ng;
@@ -577,10 +601,15 @@ EXPORT_SYMBOL_GPL(unregister_pernet_device);
 #ifdef CONFIG_NET_NS
 static void *netns_get(struct task_struct *task)
 {
-	struct net *net;
+	struct net *net = NULL;
+	struct nsproxy *nsproxy;
+
 	rcu_read_lock();
-	net = get_net(task->nsproxy->net_ns);
+	nsproxy = task_nsproxy(task);
+	if (nsproxy)
+		net = get_net(nsproxy->net_ns);
 	rcu_read_unlock();
+
 	return net;
 }
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index d7c4bb4..dca9602 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1043,6 +1043,7 @@ const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
 	[IFLA_LINKINFO]		= { .type = NLA_NESTED },
 	[IFLA_NET_NS_PID]	= { .type = NLA_U32 },
+	[IFLA_NET_NS_FD]	= { .type = NLA_U32 },
 	[IFLA_IFALIAS]	        = { .type = NLA_STRING, .len = IFALIASZ-1 },
 	[IFLA_VFINFO_LIST]	= {. type = NLA_NESTED },
 	[IFLA_VF_PORTS]		= { .type = NLA_NESTED },
@@ -1091,6 +1092,8 @@ struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[])
 	 */
 	if (tb[IFLA_NET_NS_PID])
 		net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
+	else if (tb[IFLA_NET_NS_FD])
+		net = get_net_ns_by_fd(nla_get_u32(tb[IFLA_NET_NS_FD]));
 	else
 		net = get_net(src_net);
 	return net;
@@ -1221,7 +1224,7 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
 	int send_addr_notify = 0;
 	int err;
 
-	if (tb[IFLA_NET_NS_PID]) {
+	if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD]) {
 		struct net *net = rtnl_link_get_net(dev_net(dev), tb);
 		if (IS_ERR(net)) {
 			err = PTR_ERR(net);
-- 
1.6.5.2.143.g8cc62

[PATCH 6/7] net: Allow setting the network namespace by fd

[Eric W. Biederman]

Take advantage of the new abstraction and allow network devices
to be placed in any network namespace that we have a fd to talk
about.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 include/linux/if_link.h     |    1 +
 include/net/net_namespace.h |    1 +
 net/core/net_namespace.c    |   33 +++++++++++++++++++++++++++++++--
 net/core/rtnetlink.c        |    5 ++++-
 4 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index f4a2e6b..0ee969a 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -136,6 +136,7 @@ enum {
 	IFLA_PORT_SELF,
 	IFLA_AF_SPEC,
 	IFLA_GROUP,		/* Group the device belongs to */
+	IFLA_NET_NS_FD,
 	__IFLA_MAX
 };
 
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 3ae4919..dcc8f57 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -119,6 +119,7 @@ static inline struct net *copy_net_ns(unsigned long flags, struct net *net_ns)
 extern struct list_head net_namespace_list;
 
 extern struct net *get_net_ns_by_pid(pid_t pid);
+extern struct net *get_net_ns_by_fd(int pid);
 
 #ifdef CONFIG_NET_NS
 extern void __put_net(struct net *net);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index bf7707e..b7403ff 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -8,6 +8,8 @@
 #include <linux/idr.h>
 #include <linux/rculist.h>
 #include <linux/nsproxy.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -343,6 +345,28 @@ struct net *get_net_ns_by_pid(pid_t pid)
 }
 EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
 
+struct net *get_net_ns_by_fd(int fd)
+{
+	struct proc_inode *ei;
+	struct file *file;
+	struct net *net;
+
+	net = ERR_PTR(-EINVAL);
+	file = proc_ns_fget(fd);
+	if (!file)
+		goto out;
+
+	ei = PROC_I(file->f_dentry->d_inode);
+	if (ei->ns_ops != &netns_operations)
+		goto out;
+
+	net = get_net(ei->ns);
+out:
+	if (file)
+		fput(file);
+	return net;
+}
+
 static int __init net_ns_init(void)
 {
 	struct net_generic *ng;
@@ -577,10 +601,15 @@ EXPORT_SYMBOL_GPL(unregister_pernet_device);
 #ifdef CONFIG_NET_NS
 static void *netns_get(struct task_struct *task)
 {
-	struct net *net;
+	struct net *net = NULL;
+	struct nsproxy *nsproxy;
+
 	rcu_read_lock();
-	net = get_net(task->nsproxy->net_ns);
+	nsproxy = task_nsproxy(task);
+	if (nsproxy)
+		net = get_net(nsproxy->net_ns);
 	rcu_read_unlock();
+
 	return net;
 }
 
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index d7c4bb4..dca9602 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1043,6 +1043,7 @@ const struct nla_policy ifla_policy[IFLA_MAX+1] = {
 	[IFLA_LINKMODE]		= { .type = NLA_U8 },
 	[IFLA_LINKINFO]		= { .type = NLA_NESTED },
 	[IFLA_NET_NS_PID]	= { .type = NLA_U32 },
+	[IFLA_NET_NS_FD]	= { .type = NLA_U32 },
 	[IFLA_IFALIAS]	        = { .type = NLA_STRING, .len = IFALIASZ-1 },
 	[IFLA_VFINFO_LIST]	= {. type = NLA_NESTED },
 	[IFLA_VF_PORTS]		= { .type = NLA_NESTED },
@@ -1091,6 +1092,8 @@ struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[])
 	 */
 	if (tb[IFLA_NET_NS_PID])
 		net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
+	else if (tb[IFLA_NET_NS_FD])
+		net = get_net_ns_by_fd(nla_get_u32(tb[IFLA_NET_NS_FD]));
 	else
 		net = get_net(src_net);
 	return net;
@@ -1221,7 +1224,7 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
 	int send_addr_notify = 0;
 	int err;
 
-	if (tb[IFLA_NET_NS_PID]) {
+	if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD]) {
 		struct net *net = rtnl_link_get_net(dev_net(dev), tb);
 		if (IS_ERR(net)) {
 			err = PTR_ERR(net);
-- 
1.6.5.2.143.g8cc62

Re: [PATCH 6/7] net: Allow setting the network namespace by fd

[Daniel Lezcano]

On 05/07/2011 04:25 AM, Eric W. Biederman wrote:
> Take advantage of the new abstraction and allow network devices
> to be placed in any network namespace that we have a fd to talk
> about.
>
> Signed-off-by: Eric W. Biederman<ebiederm@xmission.com>
> ---
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>

[PATCH 3/7] ns proc: Add support for the network namespace.

[Eric W. Biederman]

Implementing file descriptors for the network namespace
is simple and straight forward.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 fs/proc/namespaces.c     |    3 +++
 include/linux/proc_fs.h  |    1 +
 net/core/net_namespace.c |   31 +++++++++++++++++++++++++++++++
 3 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 6ae9f07..dcbd483 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -16,6 +16,9 @@
 
 
 static const struct proc_ns_operations *ns_entries[] = {
+#ifdef CONFIG_NET_NS
+	&netns_operations,
+#endif
 };
 
 static const struct file_operations ns_file_operations = {
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index a6d2c6d..62126ec 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -265,6 +265,7 @@ struct proc_ns_operations {
 	void (*put)(void *ns);
 	int (*install)(struct nsproxy *nsproxy, void *ns);
 };
+extern const struct proc_ns_operations netns_operations;
 
 union proc_op {
 	int (*proc_get_link)(struct inode *, struct path *);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 3f86026..bf7707e 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -573,3 +573,34 @@ void unregister_pernet_device(struct pernet_operations *ops)
 	mutex_unlock(&net_mutex);
 }
 EXPORT_SYMBOL_GPL(unregister_pernet_device);
+
+#ifdef CONFIG_NET_NS
+static void *netns_get(struct task_struct *task)
+{
+	struct net *net;
+	rcu_read_lock();
+	net = get_net(task->nsproxy->net_ns);
+	rcu_read_unlock();
+	return net;
+}
+
+static void netns_put(void *ns)
+{
+	put_net(ns);
+}
+
+static int netns_install(struct nsproxy *nsproxy, void *ns)
+{
+	put_net(nsproxy->net_ns);
+	nsproxy->net_ns = get_net(ns);
+	return 0;
+}
+
+const struct proc_ns_operations netns_operations = {
+	.name		= "net",
+	.type		= CLONE_NEWNET,
+	.get		= netns_get,
+	.put		= netns_put,
+	.install	= netns_install,
+};
+#endif
-- 
1.6.5.2.143.g8cc62

[PATCH 3/7] ns proc: Add support for the network namespace.

[Eric W. Biederman]

Implementing file descriptors for the network namespace
is simple and straight forward.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 fs/proc/namespaces.c     |    3 +++
 include/linux/proc_fs.h  |    1 +
 net/core/net_namespace.c |   31 +++++++++++++++++++++++++++++++
 3 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 6ae9f07..dcbd483 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -16,6 +16,9 @@
 
 
 static const struct proc_ns_operations *ns_entries[] = {
+#ifdef CONFIG_NET_NS
+	&netns_operations,
+#endif
 };
 
 static const struct file_operations ns_file_operations = {
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index a6d2c6d..62126ec 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -265,6 +265,7 @@ struct proc_ns_operations {
 	void (*put)(void *ns);
 	int (*install)(struct nsproxy *nsproxy, void *ns);
 };
+extern const struct proc_ns_operations netns_operations;
 
 union proc_op {
 	int (*proc_get_link)(struct inode *, struct path *);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 3f86026..bf7707e 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -573,3 +573,34 @@ void unregister_pernet_device(struct pernet_operations *ops)
 	mutex_unlock(&net_mutex);
 }
 EXPORT_SYMBOL_GPL(unregister_pernet_device);
+
+#ifdef CONFIG_NET_NS
+static void *netns_get(struct task_struct *task)
+{
+	struct net *net;
+	rcu_read_lock();
+	net = get_net(task->nsproxy->net_ns);
+	rcu_read_unlock();
+	return net;
+}
+
+static void netns_put(void *ns)
+{
+	put_net(ns);
+}
+
+static int netns_install(struct nsproxy *nsproxy, void *ns)
+{
+	put_net(nsproxy->net_ns);
+	nsproxy->net_ns = get_net(ns);
+	return 0;
+}
+
+const struct proc_ns_operations netns_operations = {
+	.name		= "net",
+	.type		= CLONE_NEWNET,
+	.get		= netns_get,
+	.put		= netns_put,
+	.install	= netns_install,
+};
+#endif
-- 
1.6.5.2.143.g8cc62

Re: [PATCH 3/7] ns proc: Add support for the network namespace.

[Daniel Lezcano]

On 05/07/2011 04:24 AM, Eric W. Biederman wrote:
> Implementing file descriptors for the network namespace
> is simple and straight forward.
>
> Signed-off-by: Eric W. Biederman<ebiederm@xmission.com>
> ---

Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>

Re: [PATCH 3/7] ns proc: Add support for the network namespace.

[Nathan Lynch]

On Fri, 2011-05-06 at 19:24 -0700, Eric W. Biederman wrote:
> diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
> index 3f86026..bf7707e 100644
> --- a/net/core/net_namespace.c
> +++ b/net/core/net_namespace.c
> @@ -573,3 +573,34 @@ void unregister_pernet_device(struct pernet_operations *ops)
>  	mutex_unlock(&net_mutex);
>  }
>  EXPORT_SYMBOL_GPL(unregister_pernet_device);
> +
> +#ifdef CONFIG_NET_NS
> +static void *netns_get(struct task_struct *task)
> +{
> +	struct net *net;
> +	rcu_read_lock();
> +	net = get_net(task->nsproxy->net_ns);

This should use task_nsproxy() and check the result before grabbing the
net_ns, but I think you fix that in a later patch.

Regardless, it looks as if all the proc_ns_ops->get() implementations
really just want the nsproxy, so maybe the get() methods should take
that instead of the task_struct, and proc_ns_instantiate() should do
something like:

struct nsproxy *nsproxy;
...

ei->ns_ops = ns_ops;
error = -ESRCH;
rcu_read_lock();
nsproxy = task_nsproxy(task);
rcu_read_unlock();
if (!nsproxy)
	got out;
ei->ns = ns_ops->get(nsproxy);


So then the zombie check is consolidated in one place instead of having
to do it in every get() method.



> +	rcu_read_unlock();
> +	return net;
> +}
> +
> +static void netns_put(void *ns)
> +{
> +	put_net(ns);
> +}
> +
> +static int netns_install(struct nsproxy *nsproxy, void *ns)
> +{
> +	put_net(nsproxy->net_ns);
> +	nsproxy->net_ns = get_net(ns);
> +	return 0;
> +}

This introduces a window where, potentially, nsproxy->net_ns is stale
before it is updated with the namespace which is being attached, no? 
(Same concern applies to other install methods in the patch set).  It
seems possible to oops the kernel in this window by looking up
/proc/$PID/ns/net while $PID is in the midst of setns().

Re: [PATCH 3/7] ns proc: Add support for the network namespace.

[Eric W. Biederman]

Nathan Lynch <ntl@pobox.com> writes:

> On Fri, 2011-05-06 at 19:24 -0700, Eric W. Biederman wrote:
>> diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
>> index 3f86026..bf7707e 100644
>> --- a/net/core/net_namespace.c
>> +++ b/net/core/net_namespace.c
>> @@ -573,3 +573,34 @@ void unregister_pernet_device(struct pernet_operations *ops)
>>  	mutex_unlock(&net_mutex);
>>  }
>>  EXPORT_SYMBOL_GPL(unregister_pernet_device);
>> +
>> +#ifdef CONFIG_NET_NS
>> +static void *netns_get(struct task_struct *task)
>> +{
>> +	struct net *net;
>> +	rcu_read_lock();
>> +	net = get_net(task->nsproxy->net_ns);
>
> This should use task_nsproxy() and check the result before grabbing the
> net_ns, but I think you fix that in a later patch.
>
> Regardless, it looks as if all the proc_ns_ops->get() implementations
> really just want the nsproxy, so maybe the get() methods should take
> that instead of the task_struct, and proc_ns_instantiate() should do
> something like:
>
> struct nsproxy *nsproxy;
> ...
>
> ei->ns_ops = ns_ops;
> error = -ESRCH;
> rcu_read_lock();
> nsproxy = task_nsproxy(task);
> rcu_read_unlock();
> if (!nsproxy)
> 	got out;
> ei->ns = ns_ops->get(nsproxy);
>
>
> So then the zombie check is consolidated in one place instead of having
> to do it in every get() method.

For the pid namespace at least I want the task not the nsproxy,
so I can use task_active_pid_namespace().

I admit that is a little asymmetrical with the install, but at
least until the details of getting the pid namespace working in
this context are worked out I don't want to reconsider the
current design.

There is also the user namespace that does not even exist in
nsproxy to consider.  I will worry about that namespace when
it happens.

Ultimately nsproxy is an space/time optimization that not all
namespaces use so forcing it in the design is probably not
what we want.

>> +	rcu_read_unlock();
>> +	return net;
>> +}
>> +
>> +static void netns_put(void *ns)
>> +{
>> +	put_net(ns);
>> +}
>> +
>> +static int netns_install(struct nsproxy *nsproxy, void *ns)
>> +{
>> +	put_net(nsproxy->net_ns);
>> +	nsproxy->net_ns = get_net(ns);
>> +	return 0;
>> +}
>
> This introduces a window where, potentially, nsproxy->net_ns is stale
> before it is updated with the namespace which is being attached, no? 
> (Same concern applies to other install methods in the patch set).  It
> seems possible to oops the kernel in this window by looking up
> /proc/$PID/ns/net while $PID is in the midst of setns().

Except the nsproxy being referred to is a brand new nsproxy, with an
extra reference count on every namespace.  current->nsproxy still
contains the reference counts of the current process.

Eric

Re: [PATCH 3/7] ns proc: Add support for the network namespace.

[Nathan Lynch]

On Wed, 2011-05-11 at 14:34 -0700, Eric W. Biederman wrote:
> Nathan Lynch <ntl@pobox.com> writes:
> 
> > On Fri, 2011-05-06 at 19:24 -0700, Eric W. Biederman wrote:
> >> diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
> >> index 3f86026..bf7707e 100644
> >> --- a/net/core/net_namespace.c
> >> +++ b/net/core/net_namespace.c
> >> @@ -573,3 +573,34 @@ void unregister_pernet_device(struct pernet_operations *ops)
> >>  	mutex_unlock(&net_mutex);
> >>  }
> >>  EXPORT_SYMBOL_GPL(unregister_pernet_device);
> >> +
> >> +#ifdef CONFIG_NET_NS
> >> +static void *netns_get(struct task_struct *task)
> >> +{
> >> +	struct net *net;
> >> +	rcu_read_lock();
> >> +	net = get_net(task->nsproxy->net_ns);
> >
> > This should use task_nsproxy() and check the result before grabbing the
> > net_ns, but I think you fix that in a later patch.
> >
> > Regardless, it looks as if all the proc_ns_ops->get() implementations
> > really just want the nsproxy, so maybe the get() methods should take
> > that instead of the task_struct, and proc_ns_instantiate() should do
> > something like:
> >
> > struct nsproxy *nsproxy;
> > ...
> >
> > ei->ns_ops = ns_ops;
> > error = -ESRCH;
> > rcu_read_lock();
> > nsproxy = task_nsproxy(task);
> > rcu_read_unlock();
> > if (!nsproxy)
> > 	got out;
> > ei->ns = ns_ops->get(nsproxy);
> >
> >
> > So then the zombie check is consolidated in one place instead of having
> > to do it in every get() method.
> 
> For the pid namespace at least I want the task not the nsproxy,
> so I can use task_active_pid_namespace().
> 
> I admit that is a little asymmetrical with the install, but at
> least until the details of getting the pid namespace working in
> this context are worked out I don't want to reconsider the
> current design.
> 
> There is also the user namespace that does not even exist in
> nsproxy to consider.  I will worry about that namespace when
> it happens.
> 
> Ultimately nsproxy is an space/time optimization that not all
> namespaces use so forcing it in the design is probably not
> what we want.

Okay.


> >> +	rcu_read_unlock();
> >> +	return net;
> >> +}
> >> +
> >> +static void netns_put(void *ns)
> >> +{
> >> +	put_net(ns);
> >> +}
> >> +
> >> +static int netns_install(struct nsproxy *nsproxy, void *ns)
> >> +{
> >> +	put_net(nsproxy->net_ns);
> >> +	nsproxy->net_ns = get_net(ns);
> >> +	return 0;
> >> +}
> >
> > This introduces a window where, potentially, nsproxy->net_ns is stale
> > before it is updated with the namespace which is being attached, no? 
> > (Same concern applies to other install methods in the patch set).  It
> > seems possible to oops the kernel in this window by looking up
> > /proc/$PID/ns/net while $PID is in the midst of setns().
> 
> Except the nsproxy being referred to is a brand new nsproxy, with an
> extra reference count on every namespace.  current->nsproxy still
> contains the reference counts of the current process.

Ahh, yeah.  Got it.  Thanks.

[PATCH 4/7] ns proc: Add support for the uts namespace

[Eric W. Biederman]

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 fs/proc/namespaces.c    |    3 +++
 include/linux/proc_fs.h |    1 +
 kernel/utsname.c        |   39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 0 deletions(-)

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index dcbd483..b017181 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -19,6 +19,9 @@ static const struct proc_ns_operations *ns_entries[] = {
 #ifdef CONFIG_NET_NS
 	&netns_operations,
 #endif
+#ifdef CONFIG_UTS_NS
+	&utsns_operations,
+#endif
 };
 
 static const struct file_operations ns_file_operations = {
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 62126ec..52aa89d 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -266,6 +266,7 @@ struct proc_ns_operations {
 	int (*install)(struct nsproxy *nsproxy, void *ns);
 };
 extern const struct proc_ns_operations netns_operations;
+extern const struct proc_ns_operations utsns_operations;
 
 union proc_op {
 	int (*proc_get_link)(struct inode *, struct path *);
diff --git a/kernel/utsname.c b/kernel/utsname.c
index 4464617..bff131b 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -15,6 +15,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/user_namespace.h>
+#include <linux/proc_fs.h>
 
 static struct uts_namespace *create_uts_ns(void)
 {
@@ -79,3 +80,41 @@ void free_uts_ns(struct kref *kref)
 	put_user_ns(ns->user_ns);
 	kfree(ns);
 }
+
+static void *utsns_get(struct task_struct *task)
+{
+	struct uts_namespace *ns = NULL;
+	struct nsproxy *nsproxy;
+
+	rcu_read_lock();
+	nsproxy = task_nsproxy(task);
+	if (nsproxy) {
+		ns = nsproxy->uts_ns;
+		get_uts_ns(ns);
+	}
+	rcu_read_unlock();
+
+	return ns;
+}
+
+static void utsns_put(void *ns)
+{
+	put_uts_ns(ns);
+}
+
+static int utsns_install(struct nsproxy *nsproxy, void *ns)
+{
+	get_uts_ns(ns);
+	put_uts_ns(nsproxy->uts_ns);
+	nsproxy->uts_ns = ns;
+	return 0;
+}
+
+const struct proc_ns_operations utsns_operations = {
+	.name		= "uts",
+	.type		= CLONE_NEWUTS,
+	.get		= utsns_get,
+	.put		= utsns_put,
+	.install	= utsns_install,
+};
+
-- 
1.6.5.2.143.g8cc62

[PATCH 4/7] ns proc: Add support for the uts namespace

[Eric W. Biederman]

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 fs/proc/namespaces.c    |    3 +++
 include/linux/proc_fs.h |    1 +
 kernel/utsname.c        |   39 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+), 0 deletions(-)

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index dcbd483..b017181 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -19,6 +19,9 @@ static const struct proc_ns_operations *ns_entries[] = {
 #ifdef CONFIG_NET_NS
 	&netns_operations,
 #endif
+#ifdef CONFIG_UTS_NS
+	&utsns_operations,
+#endif
 };
 
 static const struct file_operations ns_file_operations = {
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 62126ec..52aa89d 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -266,6 +266,7 @@ struct proc_ns_operations {
 	int (*install)(struct nsproxy *nsproxy, void *ns);
 };
 extern const struct proc_ns_operations netns_operations;
+extern const struct proc_ns_operations utsns_operations;
 
 union proc_op {
 	int (*proc_get_link)(struct inode *, struct path *);
diff --git a/kernel/utsname.c b/kernel/utsname.c
index 4464617..bff131b 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -15,6 +15,7 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/user_namespace.h>
+#include <linux/proc_fs.h>
 
 static struct uts_namespace *create_uts_ns(void)
 {
@@ -79,3 +80,41 @@ void free_uts_ns(struct kref *kref)
 	put_user_ns(ns->user_ns);
 	kfree(ns);
 }
+
+static void *utsns_get(struct task_struct *task)
+{
+	struct uts_namespace *ns = NULL;
+	struct nsproxy *nsproxy;
+
+	rcu_read_lock();
+	nsproxy = task_nsproxy(task);
+	if (nsproxy) {
+		ns = nsproxy->uts_ns;
+		get_uts_ns(ns);
+	}
+	rcu_read_unlock();
+
+	return ns;
+}
+
+static void utsns_put(void *ns)
+{
+	put_uts_ns(ns);
+}
+
+static int utsns_install(struct nsproxy *nsproxy, void *ns)
+{
+	get_uts_ns(ns);
+	put_uts_ns(nsproxy->uts_ns);
+	nsproxy->uts_ns = ns;
+	return 0;
+}
+
+const struct proc_ns_operations utsns_operations = {
+	.name		= "uts",
+	.type		= CLONE_NEWUTS,
+	.get		= utsns_get,
+	.put		= utsns_put,
+	.install	= utsns_install,
+};
+
-- 
1.6.5.2.143.g8cc62

Re: [PATCH 4/7] ns proc: Add support for the uts namespace

[Daniel Lezcano]

On 05/07/2011 04:24 AM, Eric W. Biederman wrote:
> Signed-off-by: Eric W. Biederman<ebiederm@xmission.com>
> ---

Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>

[PATCH 5/7] ns proc: Add support for the ipc namespace

[Eric W. Biederman]

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 fs/proc/namespaces.c    |    3 +++
 include/linux/proc_fs.h |    1 +
 ipc/namespace.c         |   37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 0 deletions(-)

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index b017181..f18d6d5 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -22,6 +22,9 @@ static const struct proc_ns_operations *ns_entries[] = {
 #ifdef CONFIG_UTS_NS
 	&utsns_operations,
 #endif
+#ifdef CONFIG_IPC_NS
+	&ipcns_operations,
+#endif
 };
 
 static const struct file_operations ns_file_operations = {
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 52aa89d..a23f0b7 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -267,6 +267,7 @@ struct proc_ns_operations {
 };
 extern const struct proc_ns_operations netns_operations;
 extern const struct proc_ns_operations utsns_operations;
+extern const struct proc_ns_operations ipcns_operations;
 
 union proc_op {
 	int (*proc_get_link)(struct inode *, struct path *);
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 8054c8e..ce0a647 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -12,6 +12,7 @@
 #include <linux/fs.h>
 #include <linux/mount.h>
 #include <linux/user_namespace.h>
+#include <linux/proc_fs.h>
 
 #include "util.h"
 
@@ -140,3 +141,39 @@ void put_ipc_ns(struct ipc_namespace *ns)
 		free_ipc_ns(ns);
 	}
 }
+
+static void *ipcns_get(struct task_struct *task)
+{
+	struct ipc_namespace *ns = NULL;
+	struct nsproxy *nsproxy;
+
+	rcu_read_lock();
+	nsproxy = task_nsproxy(task);
+	if (nsproxy)
+		ns = get_ipc_ns(nsproxy->ipc_ns);
+	rcu_read_unlock();
+
+	return ns;
+}
+
+static void ipcns_put(void *ns)
+{
+	return put_ipc_ns(ns);
+}
+
+static int ipcns_install(struct nsproxy *nsproxy, void *ns)
+{
+	/* Ditch state from the old ipc namespace */
+	exit_sem(current);
+	put_ipc_ns(nsproxy->ipc_ns);
+	nsproxy->ipc_ns = get_ipc_ns(ns);
+	return 0;
+}
+
+const struct proc_ns_operations ipcns_operations = {
+	.name		= "ipc",
+	.type		= CLONE_NEWIPC,
+	.get		= ipcns_get,
+	.put		= ipcns_put,
+	.install	= ipcns_install,
+};
-- 
1.6.5.2.143.g8cc62

[PATCH 5/7] ns proc: Add support for the ipc namespace

[Eric W. Biederman]

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 fs/proc/namespaces.c    |    3 +++
 include/linux/proc_fs.h |    1 +
 ipc/namespace.c         |   37 +++++++++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 0 deletions(-)

diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index b017181..f18d6d5 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -22,6 +22,9 @@ static const struct proc_ns_operations *ns_entries[] = {
 #ifdef CONFIG_UTS_NS
 	&utsns_operations,
 #endif
+#ifdef CONFIG_IPC_NS
+	&ipcns_operations,
+#endif
 };
 
 static const struct file_operations ns_file_operations = {
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index 52aa89d..a23f0b7 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -267,6 +267,7 @@ struct proc_ns_operations {
 };
 extern const struct proc_ns_operations netns_operations;
 extern const struct proc_ns_operations utsns_operations;
+extern const struct proc_ns_operations ipcns_operations;
 
 union proc_op {
 	int (*proc_get_link)(struct inode *, struct path *);
diff --git a/ipc/namespace.c b/ipc/namespace.c
index 8054c8e..ce0a647 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -12,6 +12,7 @@
 #include <linux/fs.h>
 #include <linux/mount.h>
 #include <linux/user_namespace.h>
+#include <linux/proc_fs.h>
 
 #include "util.h"
 
@@ -140,3 +141,39 @@ void put_ipc_ns(struct ipc_namespace *ns)
 		free_ipc_ns(ns);
 	}
 }
+
+static void *ipcns_get(struct task_struct *task)
+{
+	struct ipc_namespace *ns = NULL;
+	struct nsproxy *nsproxy;
+
+	rcu_read_lock();
+	nsproxy = task_nsproxy(task);
+	if (nsproxy)
+		ns = get_ipc_ns(nsproxy->ipc_ns);
+	rcu_read_unlock();
+
+	return ns;
+}
+
+static void ipcns_put(void *ns)
+{
+	return put_ipc_ns(ns);
+}
+
+static int ipcns_install(struct nsproxy *nsproxy, void *ns)
+{
+	/* Ditch state from the old ipc namespace */
+	exit_sem(current);
+	put_ipc_ns(nsproxy->ipc_ns);
+	nsproxy->ipc_ns = get_ipc_ns(ns);
+	return 0;
+}
+
+const struct proc_ns_operations ipcns_operations = {
+	.name		= "ipc",
+	.type		= CLONE_NEWIPC,
+	.get		= ipcns_get,
+	.put		= ipcns_put,
+	.install	= ipcns_install,
+};
-- 
1.6.5.2.143.g8cc62

Re: [PATCH 5/7] ns proc: Add support for the ipc namespace

[Daniel Lezcano]

On 05/07/2011 04:24 AM, Eric W. Biederman wrote:
> Signed-off-by: Eric W. Biederman<ebiederm@xmission.com>
> ---
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>

[PATCH 7/7] ns: Wire up the setns system call

[Eric W. Biederman]

v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
v4: Moved wiring up of the system call to another patch
v5: ported to v2.6.39-rc6

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 arch/alpha/include/asm/unistd.h        |    3 ++-
 arch/alpha/kernel/systbls.S            |    1 +
 arch/arm/include/asm/unistd.h          |    1 +
 arch/arm/kernel/calls.S                |    1 +
 arch/avr32/include/asm/unistd.h        |    3 ++-
 arch/avr32/kernel/syscall_table.S      |    1 +
 arch/blackfin/include/asm/unistd.h     |    3 ++-
 arch/blackfin/mach-common/entry.S      |    1 +
 arch/cris/arch-v10/kernel/entry.S      |    1 +
 arch/cris/arch-v32/kernel/entry.S      |    1 +
 arch/cris/include/asm/unistd.h         |    3 ++-
 arch/frv/include/asm/unistd.h          |    3 ++-
 arch/frv/kernel/entry.S                |    1 +
 arch/h8300/include/asm/unistd.h        |    3 ++-
 arch/h8300/kernel/syscalls.S           |    1 +
 arch/ia64/include/asm/unistd.h         |    3 ++-
 arch/ia64/kernel/entry.S               |    1 +
 arch/m32r/include/asm/unistd.h         |    3 ++-
 arch/m32r/kernel/syscall_table.S       |    1 +
 arch/m68k/include/asm/unistd.h         |    3 ++-
 arch/m68k/kernel/syscalltable.S        |    1 +
 arch/microblaze/include/asm/unistd.h   |    3 ++-
 arch/microblaze/kernel/syscall_table.S |    1 +
 arch/mips/include/asm/unistd.h         |   15 +++++++++------
 arch/mips/kernel/scall32-o32.S         |    1 +
 arch/mips/kernel/scall64-64.S          |    1 +
 arch/mips/kernel/scall64-n32.S         |    1 +
 arch/mips/kernel/scall64-o32.S         |    1 +
 arch/mn10300/include/asm/unistd.h      |    3 ++-
 arch/mn10300/kernel/entry.S            |    1 +
 arch/parisc/include/asm/unistd.h       |    4 ++--
 arch/parisc/kernel/syscall_table.S     |    1 +
 arch/powerpc/include/asm/systbl.h      |    1 +
 arch/powerpc/include/asm/unistd.h      |    3 ++-
 arch/s390/include/asm/unistd.h         |    3 ++-
 arch/s390/kernel/syscalls.S            |    1 +
 arch/sh/include/asm/unistd_32.h        |    3 ++-
 arch/sh/include/asm/unistd_64.h        |    3 ++-
 arch/sh/kernel/syscalls_32.S           |    1 +
 arch/sh/kernel/syscalls_64.S           |    1 +
 arch/sparc/include/asm/unistd.h        |    3 ++-
 arch/sparc/kernel/systbls_32.S         |    2 +-
 arch/sparc/kernel/systbls_64.S         |    4 ++--
 arch/x86/ia32/ia32entry.S              |    1 +
 arch/x86/include/asm/unistd_32.h       |    3 ++-
 arch/x86/include/asm/unistd_64.h       |    2 ++
 arch/x86/kernel/syscall_table_32.S     |    1 +
 arch/xtensa/include/asm/unistd.h       |    4 +++-
 include/asm-generic/unistd.h           |    4 +++-
 49 files changed, 81 insertions(+), 30 deletions(-)

diff --git a/arch/alpha/include/asm/unistd.h b/arch/alpha/include/asm/unistd.h
index 058937b..664383d 100644
--- a/arch/alpha/include/asm/unistd.h
+++ b/arch/alpha/include/asm/unistd.h
@@ -452,10 +452,11 @@
 #define __NR_fanotify_init		494
 #define __NR_fanotify_mark		495
 #define __NR_prlimit64			496
+#define __NR_setns                      497
 
 #ifdef __KERNEL__
 
-#define NR_SYSCALLS			497
+#define NR_SYSCALLS			498
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/alpha/kernel/systbls.S b/arch/alpha/kernel/systbls.S
index a6a1de9..4663fd5 100644
--- a/arch/alpha/kernel/systbls.S
+++ b/arch/alpha/kernel/systbls.S
@@ -515,6 +515,7 @@ sys_call_table:
 	.quad sys_fanotify_init
 	.quad sys_fanotify_mark				/* 495 */
 	.quad sys_prlimit64
+	.quad sys_setns
 
 	.size sys_call_table, . - sys_call_table
 	.type sys_call_table, @object
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 87dbe3e..41afe2e 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -400,6 +400,7 @@
 #define __NR_open_by_handle_at		(__NR_SYSCALL_BASE+371)
 #define __NR_clock_adjtime		(__NR_SYSCALL_BASE+372)
 #define __NR_syncfs			(__NR_SYSCALL_BASE+373)
+#define __NR_setns                      (__NR_SYSCALL_BASE+374)
 
 /*
  * The following SWIs are ARM private.
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index 7fbf28c..a05f759 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -383,6 +383,7 @@
 		CALL(sys_open_by_handle_at)
 		CALL(sys_clock_adjtime)
 		CALL(sys_syncfs)
+		CALL(sys_setns)
 #ifndef syscalls_counted
 .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls
 #define syscalls_counted
diff --git a/arch/avr32/include/asm/unistd.h b/arch/avr32/include/asm/unistd.h
index 89861a2..800ea91 100644
--- a/arch/avr32/include/asm/unistd.h
+++ b/arch/avr32/include/asm/unistd.h
@@ -299,9 +299,10 @@
 #define __NR_signalfd		279
 /* 280 was __NR_timerfd */
 #define __NR_eventfd		281
+#define __NR_setns              282
 
 #ifdef __KERNEL__
-#define NR_syscalls		282
+#define NR_syscalls		283
 
 /* Old stuff */
 #define __IGNORE_uselib
diff --git a/arch/avr32/kernel/syscall_table.S b/arch/avr32/kernel/syscall_table.S
index e76bad1..c7fd394 100644
--- a/arch/avr32/kernel/syscall_table.S
+++ b/arch/avr32/kernel/syscall_table.S
@@ -296,4 +296,5 @@ sys_call_table:
 	.long	sys_ni_syscall		/* 280, was sys_timerfd */
 	.long	sys_eventfd
 	.long	sys_recvmmsg
+	.long	sys_setns
 	.long	sys_ni_syscall		/* r8 is saturated at nr_syscalls */
diff --git a/arch/blackfin/include/asm/unistd.h b/arch/blackfin/include/asm/unistd.h
index ff9a9f3..b638e6b 100644
--- a/arch/blackfin/include/asm/unistd.h
+++ b/arch/blackfin/include/asm/unistd.h
@@ -397,8 +397,9 @@
 #define __NR_open_by_handle_at	376
 #define __NR_clock_adjtime	377
 #define __NR_syncfs		378
+#define __NR_setns              379
 
-#define __NR_syscall		379
+#define __NR_syscall		380
 #define NR_syscalls		__NR_syscall
 
 /* Old optional stuff no one actually uses */
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index f96933f..dda11ef 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -1753,6 +1753,7 @@ ENTRY(_sys_call_table)
 	.long _sys_open_by_handle_at
 	.long _sys_clock_adjtime
 	.long _sys_syncfs
+	.long _sys_setns
 
 	.rept NR_syscalls-(.-_sys_call_table)/4
 	.long _sys_ni_syscall
diff --git a/arch/cris/arch-v10/kernel/entry.S b/arch/cris/arch-v10/kernel/entry.S
index 0d6420d..1161883 100644
--- a/arch/cris/arch-v10/kernel/entry.S
+++ b/arch/cris/arch-v10/kernel/entry.S
@@ -937,6 +937,7 @@ sys_call_table:
 	.long sys_inotify_init1
 	.long sys_preadv
 	.long sys_pwritev
+	.long sys_setns			/* 335 */
 
         /*
          * NOTE!! This doesn't have to be exact - we just have
diff --git a/arch/cris/arch-v32/kernel/entry.S b/arch/cris/arch-v32/kernel/entry.S
index 3abf12c..84fed7e 100644
--- a/arch/cris/arch-v32/kernel/entry.S
+++ b/arch/cris/arch-v32/kernel/entry.S
@@ -880,6 +880,7 @@ sys_call_table:
 	.long sys_inotify_init1
 	.long sys_preadv
 	.long sys_pwritev
+	.long sys_setns			/* 335 */
 
         /*
          * NOTE!! This doesn't have to be exact - we just have
diff --git a/arch/cris/include/asm/unistd.h b/arch/cris/include/asm/unistd.h
index f6fad83..c59a107 100644
--- a/arch/cris/include/asm/unistd.h
+++ b/arch/cris/include/asm/unistd.h
@@ -339,10 +339,11 @@
 #define __NR_inotify_init1	332
 #define __NR_preadv		333
 #define __NR_pwritev		334
+#define __NR_setns              335
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 335
+#define NR_syscalls 336
 
 #include <arch/unistd.h>
 
diff --git a/arch/frv/include/asm/unistd.h b/arch/frv/include/asm/unistd.h
index b28da49..6470f11 100644
--- a/arch/frv/include/asm/unistd.h
+++ b/arch/frv/include/asm/unistd.h
@@ -343,10 +343,11 @@
 #define __NR_pwritev		334
 #define __NR_rt_tgsigqueueinfo	335
 #define __NR_perf_event_open	336
+#define __NR_setns              337
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 337
+#define NR_syscalls 338
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 /* #define __ARCH_WANT_OLD_READDIR */
diff --git a/arch/frv/kernel/entry.S b/arch/frv/kernel/entry.S
index 63d579b..017d6d7 100644
--- a/arch/frv/kernel/entry.S
+++ b/arch/frv/kernel/entry.S
@@ -1526,5 +1526,6 @@ sys_call_table:
 	.long sys_pwritev
 	.long sys_rt_tgsigqueueinfo	/* 335 */
 	.long sys_perf_event_open
+	.long sys_setns
 
 syscall_table_size = (. - sys_call_table)
diff --git a/arch/h8300/include/asm/unistd.h b/arch/h8300/include/asm/unistd.h
index 50f2c5a..85c9552 100644
--- a/arch/h8300/include/asm/unistd.h
+++ b/arch/h8300/include/asm/unistd.h
@@ -325,10 +325,11 @@
 #define __NR_move_pages		317
 #define __NR_getcpu		318
 #define __NR_epoll_pwait	319
+#define __NR_setns              320
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 320
+#define NR_syscalls 321
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/h8300/kernel/syscalls.S b/arch/h8300/kernel/syscalls.S
index faefaff..f4b2e67 100644
--- a/arch/h8300/kernel/syscalls.S
+++ b/arch/h8300/kernel/syscalls.S
@@ -333,6 +333,7 @@ SYMBOL_NAME_LABEL(sys_call_table)
 	.long SYMBOL_NAME(sys_ni_syscall)	/* sys_move_pages */
 	.long SYMBOL_NAME(sys_getcpu)
 	.long SYMBOL_NAME(sys_ni_syscall)	/* sys_epoll_pwait */
+	.long SYMBOL_NAME(sys_setns)		/* 320 */
 
 	.macro	call_sp addr
 	mov.l	#SYMBOL_NAME(\addr),er6
diff --git a/arch/ia64/include/asm/unistd.h b/arch/ia64/include/asm/unistd.h
index 404d037..2fbda93 100644
--- a/arch/ia64/include/asm/unistd.h
+++ b/arch/ia64/include/asm/unistd.h
@@ -319,11 +319,12 @@
 #define __NR_open_by_handle_at  	1327
 #define __NR_clock_adjtime		1328
 #define __NR_syncfs			1329
+#define __NR_setns                      1330
 
 #ifdef __KERNEL__
 
 
-#define NR_syscalls			306 /* length of syscall table */
+#define NR_syscalls			307 /* length of syscall table */
 
 /*
  * The following defines stop scripts/checksyscalls.sh from complaining about
diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
index 6de2e23..9ca8019 100644
--- a/arch/ia64/kernel/entry.S
+++ b/arch/ia64/kernel/entry.S
@@ -1775,6 +1775,7 @@ sys_call_table:
 	data8 sys_open_by_handle_at
 	data8 sys_clock_adjtime
 	data8 sys_syncfs
+	data8 sys_setns				// 1330
 
 	.org sys_call_table + 8*NR_syscalls	// guard against failures to increase NR_syscalls
 #endif /* __IA64_ASM_PARAVIRTUALIZED_NATIVE */
diff --git a/arch/m32r/include/asm/unistd.h b/arch/m32r/include/asm/unistd.h
index c705456..3c7dafc 100644
--- a/arch/m32r/include/asm/unistd.h
+++ b/arch/m32r/include/asm/unistd.h
@@ -330,10 +330,11 @@
 /* #define __NR_timerfd		322 removed */
 #define __NR_eventfd		323
 #define __NR_fallocate		324
+#define __NR_setns              325
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 325
+#define NR_syscalls 326
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_STAT64
diff --git a/arch/m32r/kernel/syscall_table.S b/arch/m32r/kernel/syscall_table.S
index 60536e2..528f2e6 100644
--- a/arch/m32r/kernel/syscall_table.S
+++ b/arch/m32r/kernel/syscall_table.S
@@ -324,3 +324,4 @@ ENTRY(sys_call_table)
 	.long sys_ni_syscall
 	.long sys_eventfd
 	.long sys_fallocate
+	.long sys_setns			/* 325 */
diff --git a/arch/m68k/include/asm/unistd.h b/arch/m68k/include/asm/unistd.h
index 29e1790..c11a093 100644
--- a/arch/m68k/include/asm/unistd.h
+++ b/arch/m68k/include/asm/unistd.h
@@ -347,10 +347,11 @@
 #define __NR_open_by_handle_at	341
 #define __NR_clock_adjtime	342
 #define __NR_syncfs		343
+#define __NR_setns              344
 
 #ifdef __KERNEL__
 
-#define NR_syscalls		344
+#define NR_syscalls		345
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/m68k/kernel/syscalltable.S b/arch/m68k/kernel/syscalltable.S
index 9b8393d..b5a7bbf 100644
--- a/arch/m68k/kernel/syscalltable.S
+++ b/arch/m68k/kernel/syscalltable.S
@@ -362,6 +362,7 @@ ENTRY(sys_call_table)
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns
 
 	.rept NR_syscalls-(.-sys_call_table)/4
 		.long sys_ni_syscall
diff --git a/arch/microblaze/include/asm/unistd.h b/arch/microblaze/include/asm/unistd.h
index 30edd61..dcebe59 100644
--- a/arch/microblaze/include/asm/unistd.h
+++ b/arch/microblaze/include/asm/unistd.h
@@ -390,8 +390,9 @@
 #define __NR_open_by_handle_at	372
 #define __NR_clock_adjtime	373
 #define __NR_syncfs		374
+#define __NR_setns              375
 
-#define __NR_syscalls		375
+#define __NR_syscalls		376
 
 #ifdef __KERNEL__
 #ifndef __ASSEMBLY__
diff --git a/arch/microblaze/kernel/syscall_table.S b/arch/microblaze/kernel/syscall_table.S
index 85cea81..d915a12 100644
--- a/arch/microblaze/kernel/syscall_table.S
+++ b/arch/microblaze/kernel/syscall_table.S
@@ -379,3 +379,4 @@ ENTRY(sys_call_table)
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns			/* 375 */
diff --git a/arch/mips/include/asm/unistd.h b/arch/mips/include/asm/unistd.h
index fa2e37e..d0d84eb 100644
--- a/arch/mips/include/asm/unistd.h
+++ b/arch/mips/include/asm/unistd.h
@@ -363,16 +363,17 @@
 #define __NR_open_by_handle_at		(__NR_Linux + 340)
 #define __NR_clock_adjtime		(__NR_Linux + 341)
 #define __NR_syncfs			(__NR_Linux + 342)
+#define __NR_setns                      (__NR_Linux + 343)
 
 /*
  * Offset of the last Linux o32 flavoured syscall
  */
-#define __NR_Linux_syscalls		342
+#define __NR_Linux_syscalls		343
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
 
 #define __NR_O32_Linux			4000
-#define __NR_O32_Linux_syscalls		342
+#define __NR_O32_Linux_syscalls		343
 
 #if _MIPS_SIM == _MIPS_SIM_ABI64
 
@@ -682,16 +683,17 @@
 #define __NR_open_by_handle_at		(__NR_Linux + 299)
 #define __NR_clock_adjtime		(__NR_Linux + 300)
 #define __NR_syncfs			(__NR_Linux + 301)
+#define __NR_setns                      (__NR_Linux + 302)
 
 /*
  * Offset of the last Linux 64-bit flavoured syscall
  */
-#define __NR_Linux_syscalls		301
+#define __NR_Linux_syscalls		302
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */
 
 #define __NR_64_Linux			5000
-#define __NR_64_Linux_syscalls		301
+#define __NR_64_Linux_syscalls		302
 
 #if _MIPS_SIM == _MIPS_SIM_NABI32
 
@@ -1006,16 +1008,17 @@
 #define __NR_open_by_handle_at		(__NR_Linux + 304)
 #define __NR_clock_adjtime		(__NR_Linux + 305)
 #define __NR_syncfs			(__NR_Linux + 306)
+#define __NR_setns                      (__NR_Linux + 307)
 
 /*
  * Offset of the last N32 flavoured syscall
  */
-#define __NR_Linux_syscalls		306
+#define __NR_Linux_syscalls		307
 
 #endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */
 
 #define __NR_N32_Linux			6000
-#define __NR_N32_Linux_syscalls		306
+#define __NR_N32_Linux_syscalls		307
 
 #ifdef __KERNEL__
 
diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S
index 7f5468b..c6a2b58 100644
--- a/arch/mips/kernel/scall32-o32.S
+++ b/arch/mips/kernel/scall32-o32.S
@@ -590,6 +590,7 @@ einval:	li	v0, -ENOSYS
 	sys	sys_open_by_handle_at	3	/* 4340 */
 	sys	sys_clock_adjtime	2
 	sys	sys_syncfs		1
+	sys	sys_setns		2
 	.endm
 
 	/* We pre-compute the number of _instruction_ bytes needed to
diff --git a/arch/mips/kernel/scall64-64.S b/arch/mips/kernel/scall64-64.S
index a2e1fcb..57e4184 100644
--- a/arch/mips/kernel/scall64-64.S
+++ b/arch/mips/kernel/scall64-64.S
@@ -429,4 +429,5 @@ sys_call_table:
 	PTR	sys_open_by_handle_at
 	PTR	sys_clock_adjtime		/* 5300 */
 	PTR	sys_syncfs
+	PTR	sys_setns
 	.size	sys_call_table,.-sys_call_table
diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S
index b2c7624..91ae887 100644
--- a/arch/mips/kernel/scall64-n32.S
+++ b/arch/mips/kernel/scall64-n32.S
@@ -429,4 +429,5 @@ EXPORT(sysn32_call_table)
 	PTR	sys_open_by_handle_at
 	PTR	compat_sys_clock_adjtime	/* 6305 */
 	PTR	sys_syncfs
+	PTR	sys_setns
 	.size	sysn32_call_table,.-sysn32_call_table
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index 049a9c8..02e6ae5 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -547,4 +547,5 @@ sys_call_table:
 	PTR	compat_sys_open_by_handle_at	/* 4340 */
 	PTR	compat_sys_clock_adjtime
 	PTR	sys_syncfs
+	PTR	sys_setns
 	.size	sys_call_table,.-sys_call_table
diff --git a/arch/mn10300/include/asm/unistd.h b/arch/mn10300/include/asm/unistd.h
index 9d056f5..faf57bb 100644
--- a/arch/mn10300/include/asm/unistd.h
+++ b/arch/mn10300/include/asm/unistd.h
@@ -349,10 +349,11 @@
 #define __NR_rt_tgsigqueueinfo	336
 #define __NR_perf_event_open	337
 #define __NR_recvmmsg		338
+#define __NR_setns              339
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 339
+#define NR_syscalls 340
 
 /*
  * specify the deprecated syscalls we want to support on this arch
diff --git a/arch/mn10300/kernel/entry.S b/arch/mn10300/kernel/entry.S
index fb93ad7..ae435e1 100644
--- a/arch/mn10300/kernel/entry.S
+++ b/arch/mn10300/kernel/entry.S
@@ -759,6 +759,7 @@ ENTRY(sys_call_table)
 	.long sys_rt_tgsigqueueinfo
 	.long sys_perf_event_open
 	.long sys_recvmmsg
+	.long sys_setns
 
 
 nr_syscalls=(.-sys_call_table)/4
diff --git a/arch/parisc/include/asm/unistd.h b/arch/parisc/include/asm/unistd.h
index 3eb82c2..bbaed57 100644
--- a/arch/parisc/include/asm/unistd.h
+++ b/arch/parisc/include/asm/unistd.h
@@ -814,9 +814,9 @@
 #define __NR_recvmmsg		(__NR_Linux + 319)
 #define __NR_accept4		(__NR_Linux + 320)
 #define __NR_prlimit64		(__NR_Linux + 321)
+#define __NR_setns              (__NR_Linux + 322)
 
-#define __NR_Linux_syscalls	(__NR_prlimit64 + 1)
-
+#define __NR_Linux_syscalls	(__NR_setns + 1)
 
 #define __IGNORE_select		/* newselect */
 #define __IGNORE_fadvise64	/* fadvise64_64 */
diff --git a/arch/parisc/kernel/syscall_table.S b/arch/parisc/kernel/syscall_table.S
index 4be85ee..151349c 100644
--- a/arch/parisc/kernel/syscall_table.S
+++ b/arch/parisc/kernel/syscall_table.S
@@ -420,6 +420,7 @@
 	ENTRY_COMP(recvmmsg)
 	ENTRY_SAME(accept4)		/* 320 */
 	ENTRY_SAME(prlimit64)
+	ENTRY_SAME(setns)
 
 	/* Nothing yet */
 
diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index 60f64b1..2a5f60c 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -352,3 +352,4 @@ SYSCALL_SPU(name_to_handle_at)
 COMPAT_SYS_SPU(open_by_handle_at)
 COMPAT_SYS_SPU(clock_adjtime)
 SYSCALL_SPU(syncfs)
+SYSCALL_SPU(setns)
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index 3c21564..2780f7a 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -371,10 +371,11 @@
 #define __NR_open_by_handle_at	346
 #define __NR_clock_adjtime	347
 #define __NR_syncfs		348
+#define __NR_setns              349
 
 #ifdef __KERNEL__
 
-#define __NR_syscalls		349
+#define __NR_syscalls		350
 
 #define __NR__exit __NR_exit
 #define NR_syscalls	__NR_syscalls
diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h
index e821525..3399bed 100644
--- a/arch/s390/include/asm/unistd.h
+++ b/arch/s390/include/asm/unistd.h
@@ -276,7 +276,8 @@
 #define __NR_open_by_handle_at	336
 #define __NR_clock_adjtime	337
 #define __NR_syncfs		338
-#define NR_syscalls 339
+#define __NR_setns              339
+#define NR_syscalls 340
 
 /* 
  * There are some system calls that are not present on 64 bit, some
diff --git a/arch/s390/kernel/syscalls.S b/arch/s390/kernel/syscalls.S
index 9c65fd4..3ec04ba 100644
--- a/arch/s390/kernel/syscalls.S
+++ b/arch/s390/kernel/syscalls.S
@@ -347,3 +347,4 @@ SYSCALL(sys_name_to_handle_at,sys_name_to_handle_at,sys_name_to_handle_at_wrappe
 SYSCALL(sys_open_by_handle_at,sys_open_by_handle_at,compat_sys_open_by_handle_at_wrapper)
 SYSCALL(sys_clock_adjtime,sys_clock_adjtime,compat_sys_clock_adjtime_wrapper)
 SYSCALL(sys_syncfs,sys_syncfs,sys_syncfs_wrapper)
+SYSCALL(sys_setns,sys_setns,sys_setns)
diff --git a/arch/sh/include/asm/unistd_32.h b/arch/sh/include/asm/unistd_32.h
index ca7765e..26c697c 100644
--- a/arch/sh/include/asm/unistd_32.h
+++ b/arch/sh/include/asm/unistd_32.h
@@ -373,8 +373,9 @@
 #define __NR_open_by_handle_at	360
 #define __NR_clock_adjtime	361
 #define __NR_syncfs		362
+#define __NR_setns              363
 
-#define NR_syscalls 363
+#define NR_syscalls 364
 
 #ifdef __KERNEL__
 
diff --git a/arch/sh/include/asm/unistd_64.h b/arch/sh/include/asm/unistd_64.h
index a694009..330668a 100644
--- a/arch/sh/include/asm/unistd_64.h
+++ b/arch/sh/include/asm/unistd_64.h
@@ -394,10 +394,11 @@
 #define __NR_open_by_handle_at	371
 #define __NR_clock_adjtime	372
 #define __NR_syncfs		373
+#define __NR_setns              374
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 374
+#define NR_syscalls 375
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/sh/kernel/syscalls_32.S b/arch/sh/kernel/syscalls_32.S
index 030966a..67dcf66 100644
--- a/arch/sh/kernel/syscalls_32.S
+++ b/arch/sh/kernel/syscalls_32.S
@@ -380,3 +380,4 @@ ENTRY(sys_call_table)
 	.long sys_open_by_handle_at	/* 360 */
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns
diff --git a/arch/sh/kernel/syscalls_64.S b/arch/sh/kernel/syscalls_64.S
index ca0a614..dade54e 100644
--- a/arch/sh/kernel/syscalls_64.S
+++ b/arch/sh/kernel/syscalls_64.S
@@ -400,3 +400,4 @@ sys_call_table:
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns
diff --git a/arch/sparc/include/asm/unistd.h b/arch/sparc/include/asm/unistd.h
index 9d897b6..10b3105 100644
--- a/arch/sparc/include/asm/unistd.h
+++ b/arch/sparc/include/asm/unistd.h
@@ -404,8 +404,9 @@
 #define __NR_open_by_handle_at	333
 #define __NR_clock_adjtime	334
 #define __NR_syncfs		335
+#define __NR_setns              336
 
-#define NR_syscalls		336
+#define NR_syscalls		337
 
 #ifdef __32bit_syscall_numbers__
 /* Sparc 32-bit only has the "setresuid32", "getresuid32" variants,
diff --git a/arch/sparc/kernel/systbls_32.S b/arch/sparc/kernel/systbls_32.S
index 47ac73c..88d0a93 100644
--- a/arch/sparc/kernel/systbls_32.S
+++ b/arch/sparc/kernel/systbls_32.S
@@ -84,4 +84,4 @@ sys_call_table:
 /*320*/	.long sys_dup3, sys_pipe2, sys_inotify_init1, sys_accept4, sys_preadv
 /*325*/	.long sys_pwritev, sys_rt_tgsigqueueinfo, sys_perf_event_open, sys_recvmmsg, sys_fanotify_init
 /*330*/	.long sys_fanotify_mark, sys_prlimit64, sys_name_to_handle_at, sys_open_by_handle_at, sys_clock_adjtime
-/*335*/	.long sys_syncfs
+/*335*/	.long sys_syncfs, sys_setns
diff --git a/arch/sparc/kernel/systbls_64.S b/arch/sparc/kernel/systbls_64.S
index 4f3170c..19cdb12 100644
--- a/arch/sparc/kernel/systbls_64.S
+++ b/arch/sparc/kernel/systbls_64.S
@@ -85,7 +85,7 @@ sys_call_table32:
 /*320*/	.word sys_dup3, sys_pipe2, sys_inotify_init1, sys_accept4, compat_sys_preadv
 	.word compat_sys_pwritev, compat_sys_rt_tgsigqueueinfo, sys_perf_event_open, compat_sys_recvmmsg, sys_fanotify_init
 /*330*/	.word sys32_fanotify_mark, sys_prlimit64, sys_name_to_handle_at, compat_sys_open_by_handle_at, compat_sys_clock_adjtime
-	.word sys_syncfs
+	.word sys_syncfs, sys_setns
 
 #endif /* CONFIG_COMPAT */
 
@@ -162,4 +162,4 @@ sys_call_table:
 /*320*/	.word sys_dup3, sys_pipe2, sys_inotify_init1, sys_accept4, sys_preadv
 	.word sys_pwritev, sys_rt_tgsigqueueinfo, sys_perf_event_open, sys_recvmmsg, sys_fanotify_init
 /*330*/	.word sys_fanotify_mark, sys_prlimit64, sys_name_to_handle_at, sys_open_by_handle_at, sys_clock_adjtime
-	.word sys_syncfs
+	.word sys_syncfs, sys_setns
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 849a9d2..58bef77 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -848,4 +848,5 @@ ia32_sys_call_table:
 	.quad compat_sys_open_by_handle_at
 	.quad compat_sys_clock_adjtime
 	.quad sys_syncfs
+	.quad sys_setns				/* 345 */
 ia32_syscall_end:
diff --git a/arch/x86/include/asm/unistd_32.h b/arch/x86/include/asm/unistd_32.h
index a755ef5..be6c177 100644
--- a/arch/x86/include/asm/unistd_32.h
+++ b/arch/x86/include/asm/unistd_32.h
@@ -350,10 +350,11 @@
 #define __NR_open_by_handle_at  342
 #define __NR_clock_adjtime	343
 #define __NR_syncfs             344
+#define __NR_setns		345
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 345
+#define NR_syscalls 346
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/include/asm/unistd_64.h b/arch/x86/include/asm/unistd_64.h
index 160fa76..c46f833 100644
--- a/arch/x86/include/asm/unistd_64.h
+++ b/arch/x86/include/asm/unistd_64.h
@@ -677,6 +677,8 @@ __SYSCALL(__NR_open_by_handle_at, sys_open_by_handle_at)
 __SYSCALL(__NR_clock_adjtime, sys_clock_adjtime)
 #define __NR_syncfs                             306
 __SYSCALL(__NR_syncfs, sys_syncfs)
+#define __NR_setns				307
+__SYSCALL(__NR_setns, sys_setns)
 
 #ifndef __NO_STUBS
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S
index abce34d..3d77b82 100644
--- a/arch/x86/kernel/syscall_table_32.S
+++ b/arch/x86/kernel/syscall_table_32.S
@@ -344,3 +344,4 @@ ENTRY(sys_call_table)
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns			/* 345 */
diff --git a/arch/xtensa/include/asm/unistd.h b/arch/xtensa/include/asm/unistd.h
index 528042c..a6f934f 100644
--- a/arch/xtensa/include/asm/unistd.h
+++ b/arch/xtensa/include/asm/unistd.h
@@ -683,8 +683,10 @@ __SYSCALL(305, sys_ni_syscall, 0)
 __SYSCALL(306, sys_eventfd, 1)
 #define __NR_recvmmsg				307
 __SYSCALL(307, sys_recvmmsg, 5)
+#define __NR_setns				308
+__SYSCALL(308, sys_setns, 2)
 
-#define __NR_syscall_count			308
+#define __NR_syscall_count			309
 
 /*
  * sysxtensa syscall handler
diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 07c40d5..5fcd304 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -654,9 +654,11 @@ __SYSCALL(__NR_open_by_handle_at, sys_open_by_handle_at)
 __SYSCALL(__NR_clock_adjtime, sys_clock_adjtime)
 #define __NR_syncfs 267
 __SYSCALL(__NR_syncfs, sys_syncfs)
+#define __NR_setns 268
+__SYSCALL(__NR_setns, sys_setns)
 
 #undef __NR_syscalls
-#define __NR_syscalls 268
+#define __NR_syscalls 269
 
 /*
  * All syscalls below here should go away really,
-- 
1.6.5.2.143.g8cc62

[PATCH 7/7] ns: Wire up the setns system call

[Eric W. Biederman]

v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
v4: Moved wiring up of the system call to another patch
v5: ported to v2.6.39-rc6

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 arch/alpha/include/asm/unistd.h        |    3 ++-
 arch/alpha/kernel/systbls.S            |    1 +
 arch/arm/include/asm/unistd.h          |    1 +
 arch/arm/kernel/calls.S                |    1 +
 arch/avr32/include/asm/unistd.h        |    3 ++-
 arch/avr32/kernel/syscall_table.S      |    1 +
 arch/blackfin/include/asm/unistd.h     |    3 ++-
 arch/blackfin/mach-common/entry.S      |    1 +
 arch/cris/arch-v10/kernel/entry.S      |    1 +
 arch/cris/arch-v32/kernel/entry.S      |    1 +
 arch/cris/include/asm/unistd.h         |    3 ++-
 arch/frv/include/asm/unistd.h          |    3 ++-
 arch/frv/kernel/entry.S                |    1 +
 arch/h8300/include/asm/unistd.h        |    3 ++-
 arch/h8300/kernel/syscalls.S           |    1 +
 arch/ia64/include/asm/unistd.h         |    3 ++-
 arch/ia64/kernel/entry.S               |    1 +
 arch/m32r/include/asm/unistd.h         |    3 ++-
 arch/m32r/kernel/syscall_table.S       |    1 +
 arch/m68k/include/asm/unistd.h         |    3 ++-
 arch/m68k/kernel/syscalltable.S        |    1 +
 arch/microblaze/include/asm/unistd.h   |    3 ++-
 arch/microblaze/kernel/syscall_table.S |    1 +
 arch/mips/include/asm/unistd.h         |   15 +++++++++------
 arch/mips/kernel/scall32-o32.S         |    1 +
 arch/mips/kernel/scall64-64.S          |    1 +
 arch/mips/kernel/scall64-n32.S         |    1 +
 arch/mips/kernel/scall64-o32.S         |    1 +
 arch/mn10300/include/asm/unistd.h      |    3 ++-
 arch/mn10300/kernel/entry.S            |    1 +
 arch/parisc/include/asm/unistd.h       |    4 ++--
 arch/parisc/kernel/syscall_table.S     |    1 +
 arch/powerpc/include/asm/systbl.h      |    1 +
 arch/powerpc/include/asm/unistd.h      |    3 ++-
 arch/s390/include/asm/unistd.h         |    3 ++-
 arch/s390/kernel/syscalls.S            |    1 +
 arch/sh/include/asm/unistd_32.h        |    3 ++-
 arch/sh/include/asm/unistd_64.h        |    3 ++-
 arch/sh/kernel/syscalls_32.S           |    1 +
 arch/sh/kernel/syscalls_64.S           |    1 +
 arch/sparc/include/asm/unistd.h        |    3 ++-
 arch/sparc/kernel/systbls_32.S         |    2 +-
 arch/sparc/kernel/systbls_64.S         |    4 ++--
 arch/x86/ia32/ia32entry.S              |    1 +
 arch/x86/include/asm/unistd_32.h       |    3 ++-
 arch/x86/include/asm/unistd_64.h       |    2 ++
 arch/x86/kernel/syscall_table_32.S     |    1 +
 arch/xtensa/include/asm/unistd.h       |    4 +++-
 include/asm-generic/unistd.h           |    4 +++-
 49 files changed, 81 insertions(+), 30 deletions(-)

diff --git a/arch/alpha/include/asm/unistd.h b/arch/alpha/include/asm/unistd.h
index 058937b..664383d 100644
--- a/arch/alpha/include/asm/unistd.h
+++ b/arch/alpha/include/asm/unistd.h
@@ -452,10 +452,11 @@
 #define __NR_fanotify_init		494
 #define __NR_fanotify_mark		495
 #define __NR_prlimit64			496
+#define __NR_setns                      497
 
 #ifdef __KERNEL__
 
-#define NR_SYSCALLS			497
+#define NR_SYSCALLS			498
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/alpha/kernel/systbls.S b/arch/alpha/kernel/systbls.S
index a6a1de9..4663fd5 100644
--- a/arch/alpha/kernel/systbls.S
+++ b/arch/alpha/kernel/systbls.S
@@ -515,6 +515,7 @@ sys_call_table:
 	.quad sys_fanotify_init
 	.quad sys_fanotify_mark				/* 495 */
 	.quad sys_prlimit64
+	.quad sys_setns
 
 	.size sys_call_table, . - sys_call_table
 	.type sys_call_table, @object
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 87dbe3e..41afe2e 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -400,6 +400,7 @@
 #define __NR_open_by_handle_at		(__NR_SYSCALL_BASE+371)
 #define __NR_clock_adjtime		(__NR_SYSCALL_BASE+372)
 #define __NR_syncfs			(__NR_SYSCALL_BASE+373)
+#define __NR_setns                      (__NR_SYSCALL_BASE+374)
 
 /*
  * The following SWIs are ARM private.
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index 7fbf28c..a05f759 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -383,6 +383,7 @@
 		CALL(sys_open_by_handle_at)
 		CALL(sys_clock_adjtime)
 		CALL(sys_syncfs)
+		CALL(sys_setns)
 #ifndef syscalls_counted
 .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls
 #define syscalls_counted
diff --git a/arch/avr32/include/asm/unistd.h b/arch/avr32/include/asm/unistd.h
index 89861a2..800ea91 100644
--- a/arch/avr32/include/asm/unistd.h
+++ b/arch/avr32/include/asm/unistd.h
@@ -299,9 +299,10 @@
 #define __NR_signalfd		279
 /* 280 was __NR_timerfd */
 #define __NR_eventfd		281
+#define __NR_setns              282
 
 #ifdef __KERNEL__
-#define NR_syscalls		282
+#define NR_syscalls		283
 
 /* Old stuff */
 #define __IGNORE_uselib
diff --git a/arch/avr32/kernel/syscall_table.S b/arch/avr32/kernel/syscall_table.S
index e76bad1..c7fd394 100644
--- a/arch/avr32/kernel/syscall_table.S
+++ b/arch/avr32/kernel/syscall_table.S
@@ -296,4 +296,5 @@ sys_call_table:
 	.long	sys_ni_syscall		/* 280, was sys_timerfd */
 	.long	sys_eventfd
 	.long	sys_recvmmsg
+	.long	sys_setns
 	.long	sys_ni_syscall		/* r8 is saturated at nr_syscalls */
diff --git a/arch/blackfin/include/asm/unistd.h b/arch/blackfin/include/asm/unistd.h
index ff9a9f3..b638e6b 100644
--- a/arch/blackfin/include/asm/unistd.h
+++ b/arch/blackfin/include/asm/unistd.h
@@ -397,8 +397,9 @@
 #define __NR_open_by_handle_at	376
 #define __NR_clock_adjtime	377
 #define __NR_syncfs		378
+#define __NR_setns              379
 
-#define __NR_syscall		379
+#define __NR_syscall		380
 #define NR_syscalls		__NR_syscall
 
 /* Old optional stuff no one actually uses */
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index f96933f..dda11ef 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -1753,6 +1753,7 @@ ENTRY(_sys_call_table)
 	.long _sys_open_by_handle_at
 	.long _sys_clock_adjtime
 	.long _sys_syncfs
+	.long _sys_setns
 
 	.rept NR_syscalls-(.-_sys_call_table)/4
 	.long _sys_ni_syscall
diff --git a/arch/cris/arch-v10/kernel/entry.S b/arch/cris/arch-v10/kernel/entry.S
index 0d6420d..1161883 100644
--- a/arch/cris/arch-v10/kernel/entry.S
+++ b/arch/cris/arch-v10/kernel/entry.S
@@ -937,6 +937,7 @@ sys_call_table:
 	.long sys_inotify_init1
 	.long sys_preadv
 	.long sys_pwritev
+	.long sys_setns			/* 335 */
 
         /*
          * NOTE!! This doesn't have to be exact - we just have
diff --git a/arch/cris/arch-v32/kernel/entry.S b/arch/cris/arch-v32/kernel/entry.S
index 3abf12c..84fed7e 100644
--- a/arch/cris/arch-v32/kernel/entry.S
+++ b/arch/cris/arch-v32/kernel/entry.S
@@ -880,6 +880,7 @@ sys_call_table:
 	.long sys_inotify_init1
 	.long sys_preadv
 	.long sys_pwritev
+	.long sys_setns			/* 335 */
 
         /*
          * NOTE!! This doesn't have to be exact - we just have
diff --git a/arch/cris/include/asm/unistd.h b/arch/cris/include/asm/unistd.h
index f6fad83..c59a107 100644
--- a/arch/cris/include/asm/unistd.h
+++ b/arch/cris/include/asm/unistd.h
@@ -339,10 +339,11 @@
 #define __NR_inotify_init1	332
 #define __NR_preadv		333
 #define __NR_pwritev		334
+#define __NR_setns              335
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 335
+#define NR_syscalls 336
 
 #include <arch/unistd.h>
 
diff --git a/arch/frv/include/asm/unistd.h b/arch/frv/include/asm/unistd.h
index b28da49..6470f11 100644
--- a/arch/frv/include/asm/unistd.h
+++ b/arch/frv/include/asm/unistd.h
@@ -343,10 +343,11 @@
 #define __NR_pwritev		334
 #define __NR_rt_tgsigqueueinfo	335
 #define __NR_perf_event_open	336
+#define __NR_setns              337
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 337
+#define NR_syscalls 338
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 /* #define __ARCH_WANT_OLD_READDIR */
diff --git a/arch/frv/kernel/entry.S b/arch/frv/kernel/entry.S
index 63d579b..017d6d7 100644
--- a/arch/frv/kernel/entry.S
+++ b/arch/frv/kernel/entry.S
@@ -1526,5 +1526,6 @@ sys_call_table:
 	.long sys_pwritev
 	.long sys_rt_tgsigqueueinfo	/* 335 */
 	.long sys_perf_event_open
+	.long sys_setns
 
 syscall_table_size = (. - sys_call_table)
diff --git a/arch/h8300/include/asm/unistd.h b/arch/h8300/include/asm/unistd.h
index 50f2c5a..85c9552 100644
--- a/arch/h8300/include/asm/unistd.h
+++ b/arch/h8300/include/asm/unistd.h
@@ -325,10 +325,11 @@
 #define __NR_move_pages		317
 #define __NR_getcpu		318
 #define __NR_epoll_pwait	319
+#define __NR_setns              320
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 320
+#define NR_syscalls 321
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/h8300/kernel/syscalls.S b/arch/h8300/kernel/syscalls.S
index faefaff..f4b2e67 100644
--- a/arch/h8300/kernel/syscalls.S
+++ b/arch/h8300/kernel/syscalls.S
@@ -333,6 +333,7 @@ SYMBOL_NAME_LABEL(sys_call_table)
 	.long SYMBOL_NAME(sys_ni_syscall)	/* sys_move_pages */
 	.long SYMBOL_NAME(sys_getcpu)
 	.long SYMBOL_NAME(sys_ni_syscall)	/* sys_epoll_pwait */
+	.long SYMBOL_NAME(sys_setns)		/* 320 */
 
 	.macro	call_sp addr
 	mov.l	#SYMBOL_NAME(\addr),er6
diff --git a/arch/ia64/include/asm/unistd.h b/arch/ia64/include/asm/unistd.h
index 404d037..2fbda93 100644
--- a/arch/ia64/include/asm/unistd.h
+++ b/arch/ia64/include/asm/unistd.h
@@ -319,11 +319,12 @@
 #define __NR_open_by_handle_at  	1327
 #define __NR_clock_adjtime		1328
 #define __NR_syncfs			1329
+#define __NR_setns                      1330
 
 #ifdef __KERNEL__
 
 
-#define NR_syscalls			306 /* length of syscall table */
+#define NR_syscalls			307 /* length of syscall table */
 
 /*
  * The following defines stop scripts/checksyscalls.sh from complaining about
diff --git a/arch/ia64/kernel/entry.S b/arch/ia64/kernel/entry.S
index 6de2e23..9ca8019 100644
--- a/arch/ia64/kernel/entry.S
+++ b/arch/ia64/kernel/entry.S
@@ -1775,6 +1775,7 @@ sys_call_table:
 	data8 sys_open_by_handle_at
 	data8 sys_clock_adjtime
 	data8 sys_syncfs
+	data8 sys_setns				// 1330
 
 	.org sys_call_table + 8*NR_syscalls	// guard against failures to increase NR_syscalls
 #endif /* __IA64_ASM_PARAVIRTUALIZED_NATIVE */
diff --git a/arch/m32r/include/asm/unistd.h b/arch/m32r/include/asm/unistd.h
index c705456..3c7dafc 100644
--- a/arch/m32r/include/asm/unistd.h
+++ b/arch/m32r/include/asm/unistd.h
@@ -330,10 +330,11 @@
 /* #define __NR_timerfd		322 removed */
 #define __NR_eventfd		323
 #define __NR_fallocate		324
+#define __NR_setns              325
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 325
+#define NR_syscalls 326
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_STAT64
diff --git a/arch/m32r/kernel/syscall_table.S b/arch/m32r/kernel/syscall_table.S
index 60536e2..528f2e6 100644
--- a/arch/m32r/kernel/syscall_table.S
+++ b/arch/m32r/kernel/syscall_table.S
@@ -324,3 +324,4 @@ ENTRY(sys_call_table)
 	.long sys_ni_syscall
 	.long sys_eventfd
 	.long sys_fallocate
+	.long sys_setns			/* 325 */
diff --git a/arch/m68k/include/asm/unistd.h b/arch/m68k/include/asm/unistd.h
index 29e1790..c11a093 100644
--- a/arch/m68k/include/asm/unistd.h
+++ b/arch/m68k/include/asm/unistd.h
@@ -347,10 +347,11 @@
 #define __NR_open_by_handle_at	341
 #define __NR_clock_adjtime	342
 #define __NR_syncfs		343
+#define __NR_setns              344
 
 #ifdef __KERNEL__
 
-#define NR_syscalls		344
+#define NR_syscalls		345
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/m68k/kernel/syscalltable.S b/arch/m68k/kernel/syscalltable.S
index 9b8393d..b5a7bbf 100644
--- a/arch/m68k/kernel/syscalltable.S
+++ b/arch/m68k/kernel/syscalltable.S
@@ -362,6 +362,7 @@ ENTRY(sys_call_table)
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns
 
 	.rept NR_syscalls-(.-sys_call_table)/4
 		.long sys_ni_syscall
diff --git a/arch/microblaze/include/asm/unistd.h b/arch/microblaze/include/asm/unistd.h
index 30edd61..dcebe59 100644
--- a/arch/microblaze/include/asm/unistd.h
+++ b/arch/microblaze/include/asm/unistd.h
@@ -390,8 +390,9 @@
 #define __NR_open_by_handle_at	372
 #define __NR_clock_adjtime	373
 #define __NR_syncfs		374
+#define __NR_setns              375
 
-#define __NR_syscalls		375
+#define __NR_syscalls		376
 
 #ifdef __KERNEL__
 #ifndef __ASSEMBLY__
diff --git a/arch/microblaze/kernel/syscall_table.S b/arch/microblaze/kernel/syscall_table.S
index 85cea81..d915a12 100644
--- a/arch/microblaze/kernel/syscall_table.S
+++ b/arch/microblaze/kernel/syscall_table.S
@@ -379,3 +379,4 @@ ENTRY(sys_call_table)
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns			/* 375 */
diff --git a/arch/mips/include/asm/unistd.h b/arch/mips/include/asm/unistd.h
index fa2e37e..d0d84eb 100644
--- a/arch/mips/include/asm/unistd.h
+++ b/arch/mips/include/asm/unistd.h
@@ -363,16 +363,17 @@
 #define __NR_open_by_handle_at		(__NR_Linux + 340)
 #define __NR_clock_adjtime		(__NR_Linux + 341)
 #define __NR_syncfs			(__NR_Linux + 342)
+#define __NR_setns                      (__NR_Linux + 343)
 
 /*
  * Offset of the last Linux o32 flavoured syscall
  */
-#define __NR_Linux_syscalls		342
+#define __NR_Linux_syscalls		343
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */
 
 #define __NR_O32_Linux			4000
-#define __NR_O32_Linux_syscalls		342
+#define __NR_O32_Linux_syscalls		343
 
 #if _MIPS_SIM == _MIPS_SIM_ABI64
 
@@ -682,16 +683,17 @@
 #define __NR_open_by_handle_at		(__NR_Linux + 299)
 #define __NR_clock_adjtime		(__NR_Linux + 300)
 #define __NR_syncfs			(__NR_Linux + 301)
+#define __NR_setns                      (__NR_Linux + 302)
 
 /*
  * Offset of the last Linux 64-bit flavoured syscall
  */
-#define __NR_Linux_syscalls		301
+#define __NR_Linux_syscalls		302
 
 #endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */
 
 #define __NR_64_Linux			5000
-#define __NR_64_Linux_syscalls		301
+#define __NR_64_Linux_syscalls		302
 
 #if _MIPS_SIM == _MIPS_SIM_NABI32
 
@@ -1006,16 +1008,17 @@
 #define __NR_open_by_handle_at		(__NR_Linux + 304)
 #define __NR_clock_adjtime		(__NR_Linux + 305)
 #define __NR_syncfs			(__NR_Linux + 306)
+#define __NR_setns                      (__NR_Linux + 307)
 
 /*
  * Offset of the last N32 flavoured syscall
  */
-#define __NR_Linux_syscalls		306
+#define __NR_Linux_syscalls		307
 
 #endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */
 
 #define __NR_N32_Linux			6000
-#define __NR_N32_Linux_syscalls		306
+#define __NR_N32_Linux_syscalls		307
 
 #ifdef __KERNEL__
 
diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S
index 7f5468b..c6a2b58 100644
--- a/arch/mips/kernel/scall32-o32.S
+++ b/arch/mips/kernel/scall32-o32.S
@@ -590,6 +590,7 @@ einval:	li	v0, -ENOSYS
 	sys	sys_open_by_handle_at	3	/* 4340 */
 	sys	sys_clock_adjtime	2
 	sys	sys_syncfs		1
+	sys	sys_setns		2
 	.endm
 
 	/* We pre-compute the number of _instruction_ bytes needed to
diff --git a/arch/mips/kernel/scall64-64.S b/arch/mips/kernel/scall64-64.S
index a2e1fcb..57e4184 100644
--- a/arch/mips/kernel/scall64-64.S
+++ b/arch/mips/kernel/scall64-64.S
@@ -429,4 +429,5 @@ sys_call_table:
 	PTR	sys_open_by_handle_at
 	PTR	sys_clock_adjtime		/* 5300 */
 	PTR	sys_syncfs
+	PTR	sys_setns
 	.size	sys_call_table,.-sys_call_table
diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S
index b2c7624..91ae887 100644
--- a/arch/mips/kernel/scall64-n32.S
+++ b/arch/mips/kernel/scall64-n32.S
@@ -429,4 +429,5 @@ EXPORT(sysn32_call_table)
 	PTR	sys_open_by_handle_at
 	PTR	compat_sys_clock_adjtime	/* 6305 */
 	PTR	sys_syncfs
+	PTR	sys_setns
 	.size	sysn32_call_table,.-sysn32_call_table
diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S
index 049a9c8..02e6ae5 100644
--- a/arch/mips/kernel/scall64-o32.S
+++ b/arch/mips/kernel/scall64-o32.S
@@ -547,4 +547,5 @@ sys_call_table:
 	PTR	compat_sys_open_by_handle_at	/* 4340 */
 	PTR	compat_sys_clock_adjtime
 	PTR	sys_syncfs
+	PTR	sys_setns
 	.size	sys_call_table,.-sys_call_table
diff --git a/arch/mn10300/include/asm/unistd.h b/arch/mn10300/include/asm/unistd.h
index 9d056f5..faf57bb 100644
--- a/arch/mn10300/include/asm/unistd.h
+++ b/arch/mn10300/include/asm/unistd.h
@@ -349,10 +349,11 @@
 #define __NR_rt_tgsigqueueinfo	336
 #define __NR_perf_event_open	337
 #define __NR_recvmmsg		338
+#define __NR_setns              339
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 339
+#define NR_syscalls 340
 
 /*
  * specify the deprecated syscalls we want to support on this arch
diff --git a/arch/mn10300/kernel/entry.S b/arch/mn10300/kernel/entry.S
index fb93ad7..ae435e1 100644
--- a/arch/mn10300/kernel/entry.S
+++ b/arch/mn10300/kernel/entry.S
@@ -759,6 +759,7 @@ ENTRY(sys_call_table)
 	.long sys_rt_tgsigqueueinfo
 	.long sys_perf_event_open
 	.long sys_recvmmsg
+	.long sys_setns
 
 
 nr_syscalls=(.-sys_call_table)/4
diff --git a/arch/parisc/include/asm/unistd.h b/arch/parisc/include/asm/unistd.h
index 3eb82c2..bbaed57 100644
--- a/arch/parisc/include/asm/unistd.h
+++ b/arch/parisc/include/asm/unistd.h
@@ -814,9 +814,9 @@
 #define __NR_recvmmsg		(__NR_Linux + 319)
 #define __NR_accept4		(__NR_Linux + 320)
 #define __NR_prlimit64		(__NR_Linux + 321)
+#define __NR_setns              (__NR_Linux + 322)
 
-#define __NR_Linux_syscalls	(__NR_prlimit64 + 1)
-
+#define __NR_Linux_syscalls	(__NR_setns + 1)
 
 #define __IGNORE_select		/* newselect */
 #define __IGNORE_fadvise64	/* fadvise64_64 */
diff --git a/arch/parisc/kernel/syscall_table.S b/arch/parisc/kernel/syscall_table.S
index 4be85ee..151349c 100644
--- a/arch/parisc/kernel/syscall_table.S
+++ b/arch/parisc/kernel/syscall_table.S
@@ -420,6 +420,7 @@
 	ENTRY_COMP(recvmmsg)
 	ENTRY_SAME(accept4)		/* 320 */
 	ENTRY_SAME(prlimit64)
+	ENTRY_SAME(setns)
 
 	/* Nothing yet */
 
diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index 60f64b1..2a5f60c 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -352,3 +352,4 @@ SYSCALL_SPU(name_to_handle_at)
 COMPAT_SYS_SPU(open_by_handle_at)
 COMPAT_SYS_SPU(clock_adjtime)
 SYSCALL_SPU(syncfs)
+SYSCALL_SPU(setns)
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index 3c21564..2780f7a 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -371,10 +371,11 @@
 #define __NR_open_by_handle_at	346
 #define __NR_clock_adjtime	347
 #define __NR_syncfs		348
+#define __NR_setns              349
 
 #ifdef __KERNEL__
 
-#define __NR_syscalls		349
+#define __NR_syscalls		350
 
 #define __NR__exit __NR_exit
 #define NR_syscalls	__NR_syscalls
diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h
index e821525..3399bed 100644
--- a/arch/s390/include/asm/unistd.h
+++ b/arch/s390/include/asm/unistd.h
@@ -276,7 +276,8 @@
 #define __NR_open_by_handle_at	336
 #define __NR_clock_adjtime	337
 #define __NR_syncfs		338
-#define NR_syscalls 339
+#define __NR_setns              339
+#define NR_syscalls 340
 
 /* 
  * There are some system calls that are not present on 64 bit, some
diff --git a/arch/s390/kernel/syscalls.S b/arch/s390/kernel/syscalls.S
index 9c65fd4..3ec04ba 100644
--- a/arch/s390/kernel/syscalls.S
+++ b/arch/s390/kernel/syscalls.S
@@ -347,3 +347,4 @@ SYSCALL(sys_name_to_handle_at,sys_name_to_handle_at,sys_name_to_handle_at_wrappe
 SYSCALL(sys_open_by_handle_at,sys_open_by_handle_at,compat_sys_open_by_handle_at_wrapper)
 SYSCALL(sys_clock_adjtime,sys_clock_adjtime,compat_sys_clock_adjtime_wrapper)
 SYSCALL(sys_syncfs,sys_syncfs,sys_syncfs_wrapper)
+SYSCALL(sys_setns,sys_setns,sys_setns)
diff --git a/arch/sh/include/asm/unistd_32.h b/arch/sh/include/asm/unistd_32.h
index ca7765e..26c697c 100644
--- a/arch/sh/include/asm/unistd_32.h
+++ b/arch/sh/include/asm/unistd_32.h
@@ -373,8 +373,9 @@
 #define __NR_open_by_handle_at	360
 #define __NR_clock_adjtime	361
 #define __NR_syncfs		362
+#define __NR_setns              363
 
-#define NR_syscalls 363
+#define NR_syscalls 364
 
 #ifdef __KERNEL__
 
diff --git a/arch/sh/include/asm/unistd_64.h b/arch/sh/include/asm/unistd_64.h
index a694009..330668a 100644
--- a/arch/sh/include/asm/unistd_64.h
+++ b/arch/sh/include/asm/unistd_64.h
@@ -394,10 +394,11 @@
 #define __NR_open_by_handle_at	371
 #define __NR_clock_adjtime	372
 #define __NR_syncfs		373
+#define __NR_setns              374
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 374
+#define NR_syscalls 375
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/sh/kernel/syscalls_32.S b/arch/sh/kernel/syscalls_32.S
index 030966a..67dcf66 100644
--- a/arch/sh/kernel/syscalls_32.S
+++ b/arch/sh/kernel/syscalls_32.S
@@ -380,3 +380,4 @@ ENTRY(sys_call_table)
 	.long sys_open_by_handle_at	/* 360 */
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns
diff --git a/arch/sh/kernel/syscalls_64.S b/arch/sh/kernel/syscalls_64.S
index ca0a614..dade54e 100644
--- a/arch/sh/kernel/syscalls_64.S
+++ b/arch/sh/kernel/syscalls_64.S
@@ -400,3 +400,4 @@ sys_call_table:
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns
diff --git a/arch/sparc/include/asm/unistd.h b/arch/sparc/include/asm/unistd.h
index 9d897b6..10b3105 100644
--- a/arch/sparc/include/asm/unistd.h
+++ b/arch/sparc/include/asm/unistd.h
@@ -404,8 +404,9 @@
 #define __NR_open_by_handle_at	333
 #define __NR_clock_adjtime	334
 #define __NR_syncfs		335
+#define __NR_setns              336
 
-#define NR_syscalls		336
+#define NR_syscalls		337
 
 #ifdef __32bit_syscall_numbers__
 /* Sparc 32-bit only has the "setresuid32", "getresuid32" variants,
diff --git a/arch/sparc/kernel/systbls_32.S b/arch/sparc/kernel/systbls_32.S
index 47ac73c..88d0a93 100644
--- a/arch/sparc/kernel/systbls_32.S
+++ b/arch/sparc/kernel/systbls_32.S
@@ -84,4 +84,4 @@ sys_call_table:
 /*320*/	.long sys_dup3, sys_pipe2, sys_inotify_init1, sys_accept4, sys_preadv
 /*325*/	.long sys_pwritev, sys_rt_tgsigqueueinfo, sys_perf_event_open, sys_recvmmsg, sys_fanotify_init
 /*330*/	.long sys_fanotify_mark, sys_prlimit64, sys_name_to_handle_at, sys_open_by_handle_at, sys_clock_adjtime
-/*335*/	.long sys_syncfs
+/*335*/	.long sys_syncfs, sys_setns
diff --git a/arch/sparc/kernel/systbls_64.S b/arch/sparc/kernel/systbls_64.S
index 4f3170c..19cdb12 100644
--- a/arch/sparc/kernel/systbls_64.S
+++ b/arch/sparc/kernel/systbls_64.S
@@ -85,7 +85,7 @@ sys_call_table32:
 /*320*/	.word sys_dup3, sys_pipe2, sys_inotify_init1, sys_accept4, compat_sys_preadv
 	.word compat_sys_pwritev, compat_sys_rt_tgsigqueueinfo, sys_perf_event_open, compat_sys_recvmmsg, sys_fanotify_init
 /*330*/	.word sys32_fanotify_mark, sys_prlimit64, sys_name_to_handle_at, compat_sys_open_by_handle_at, compat_sys_clock_adjtime
-	.word sys_syncfs
+	.word sys_syncfs, sys_setns
 
 #endif /* CONFIG_COMPAT */
 
@@ -162,4 +162,4 @@ sys_call_table:
 /*320*/	.word sys_dup3, sys_pipe2, sys_inotify_init1, sys_accept4, sys_preadv
 	.word sys_pwritev, sys_rt_tgsigqueueinfo, sys_perf_event_open, sys_recvmmsg, sys_fanotify_init
 /*330*/	.word sys_fanotify_mark, sys_prlimit64, sys_name_to_handle_at, sys_open_by_handle_at, sys_clock_adjtime
-	.word sys_syncfs
+	.word sys_syncfs, sys_setns
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index 849a9d2..58bef77 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -848,4 +848,5 @@ ia32_sys_call_table:
 	.quad compat_sys_open_by_handle_at
 	.quad compat_sys_clock_adjtime
 	.quad sys_syncfs
+	.quad sys_setns				/* 345 */
 ia32_syscall_end:
diff --git a/arch/x86/include/asm/unistd_32.h b/arch/x86/include/asm/unistd_32.h
index a755ef5..be6c177 100644
--- a/arch/x86/include/asm/unistd_32.h
+++ b/arch/x86/include/asm/unistd_32.h
@@ -350,10 +350,11 @@
 #define __NR_open_by_handle_at  342
 #define __NR_clock_adjtime	343
 #define __NR_syncfs             344
+#define __NR_setns		345
 
 #ifdef __KERNEL__
 
-#define NR_syscalls 345
+#define NR_syscalls 346
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/include/asm/unistd_64.h b/arch/x86/include/asm/unistd_64.h
index 160fa76..c46f833 100644
--- a/arch/x86/include/asm/unistd_64.h
+++ b/arch/x86/include/asm/unistd_64.h
@@ -677,6 +677,8 @@ __SYSCALL(__NR_open_by_handle_at, sys_open_by_handle_at)
 __SYSCALL(__NR_clock_adjtime, sys_clock_adjtime)
 #define __NR_syncfs                             306
 __SYSCALL(__NR_syncfs, sys_syncfs)
+#define __NR_setns				307
+__SYSCALL(__NR_setns, sys_setns)
 
 #ifndef __NO_STUBS
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S
index abce34d..3d77b82 100644
--- a/arch/x86/kernel/syscall_table_32.S
+++ b/arch/x86/kernel/syscall_table_32.S
@@ -344,3 +344,4 @@ ENTRY(sys_call_table)
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns			/* 345 */
diff --git a/arch/xtensa/include/asm/unistd.h b/arch/xtensa/include/asm/unistd.h
index 528042c..a6f934f 100644
--- a/arch/xtensa/include/asm/unistd.h
+++ b/arch/xtensa/include/asm/unistd.h
@@ -683,8 +683,10 @@ __SYSCALL(305, sys_ni_syscall, 0)
 __SYSCALL(306, sys_eventfd, 1)
 #define __NR_recvmmsg				307
 __SYSCALL(307, sys_recvmmsg, 5)
+#define __NR_setns				308
+__SYSCALL(308, sys_setns, 2)
 
-#define __NR_syscall_count			308
+#define __NR_syscall_count			309
 
 /*
  * sysxtensa syscall handler
diff --git a/include/asm-generic/unistd.h b/include/asm-generic/unistd.h
index 07c40d5..5fcd304 100644
--- a/include/asm-generic/unistd.h
+++ b/include/asm-generic/unistd.h
@@ -654,9 +654,11 @@ __SYSCALL(__NR_open_by_handle_at, sys_open_by_handle_at)
 __SYSCALL(__NR_clock_adjtime, sys_clock_adjtime)
 #define __NR_syncfs 267
 __SYSCALL(__NR_syncfs, sys_syncfs)
+#define __NR_setns 268
+__SYSCALL(__NR_setns, sys_setns)
 
 #undef __NR_syscalls
-#define __NR_syscalls 268
+#define __NR_syscalls 269
 
 /*
  * All syscalls below here should go away really,
-- 
1.6.5.2.143.g8cc62

Re: [PATCH 7/7] ns: Wire up the setns system call

[Geert Uytterhoeven]

On Sat, May 7, 2011 at 04:25, Eric W. Biederman <ebiederm@xmission.com> wrote:
>  arch/m68k/include/asm/unistd.h         |    3 ++-
>  arch/m68k/kernel/syscalltable.S        |    1 +

As the unified syscalltable for m68k/m68knommu is not yet in mainline
(planned for
2.6.40), you should also add it to arch/m68k/kernel/entry_mm.S.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 7/7] ns: Wire up the setns system call

[Eric W. Biederman]

Geert Uytterhoeven <geert@linux-m68k.org> writes:

> On Sat, May 7, 2011 at 04:25, Eric W. Biederman <ebiederm@xmission.com> wrote:
>>  arch/m68k/include/asm/unistd.h         |    3 ++-
>>  arch/m68k/kernel/syscalltable.S        |    1 +
>
> As the unified syscalltable for m68k/m68knommu is not yet in mainline
> (planned for
> 2.6.40), you should also add it to arch/m68k/kernel/entry_mm.S.
>
> Gr{oetje,eeting}s,

Like so?

From c06a03281d944ed36e2da02f5374ec6c650e4988 Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Sat, 7 May 2011 07:00:24 -0700
Subject: [PATCH] m68knommu: Wire up the setns system call

It seems I overlooked m68knommu where I wired up this syscall.

Reported-by:  Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 arch/m68k/kernel/entry_mm.S |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/m68k/kernel/entry_mm.S b/arch/m68k/kernel/entry_mm.S
index 1359ee6..e048015 100644
--- a/arch/m68k/kernel/entry_mm.S
+++ b/arch/m68k/kernel/entry_mm.S
@@ -754,4 +754,5 @@ sys_call_table:
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns
 
-- 
1.7.5.1.217.g4e3aa

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Re: [PATCH 7/7] ns: Wire up the setns system call

[Eric W. Biederman]

Geert Uytterhoeven <geert@linux-m68k.org> writes:

> On Sat, May 7, 2011 at 04:25, Eric W. Biederman <ebiederm@xmission.com> wrote:
>>  arch/m68k/include/asm/unistd.h         |    3 ++-
>>  arch/m68k/kernel/syscalltable.S        |    1 +
>
> As the unified syscalltable for m68k/m68knommu is not yet in mainline
> (planned for
> 2.6.40), you should also add it to arch/m68k/kernel/entry_mm.S.
>
> Gr{oetje,eeting}s,

Like so?

From c06a03281d944ed36e2da02f5374ec6c650e4988 Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Sat, 7 May 2011 07:00:24 -0700
Subject: [PATCH] m68knommu: Wire up the setns system call

It seems I overlooked m68knommu where I wired up this syscall.

Reported-by:  Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 arch/m68k/kernel/entry_mm.S |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/m68k/kernel/entry_mm.S b/arch/m68k/kernel/entry_mm.S
index 1359ee6..e048015 100644
--- a/arch/m68k/kernel/entry_mm.S
+++ b/arch/m68k/kernel/entry_mm.S
@@ -754,4 +754,5 @@ sys_call_table:
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns
 
-- 
1.7.5.1.217.g4e3aa

Re: [PATCH 7/7] ns: Wire up the setns system call

[Eric W. Biederman]

Geert Uytterhoeven <geert@linux-m68k.org> writes:

> On Sat, May 7, 2011 at 04:25, Eric W. Biederman <ebiederm@xmission.com> wrote:
>>  arch/m68k/include/asm/unistd.h         |    3 ++-
>>  arch/m68k/kernel/syscalltable.S        |    1 +
>
> As the unified syscalltable for m68k/m68knommu is not yet in mainline
> (planned for
> 2.6.40), you should also add it to arch/m68k/kernel/entry_mm.S.
>
> Gr{oetje,eeting}s,

Like so?

>From c06a03281d944ed36e2da02f5374ec6c650e4988 Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Sat, 7 May 2011 07:00:24 -0700
Subject: [PATCH] m68knommu: Wire up the setns system call

It seems I overlooked m68knommu where I wired up this syscall.

Reported-by:  Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 arch/m68k/kernel/entry_mm.S |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/m68k/kernel/entry_mm.S b/arch/m68k/kernel/entry_mm.S
index 1359ee6..e048015 100644
--- a/arch/m68k/kernel/entry_mm.S
+++ b/arch/m68k/kernel/entry_mm.S
@@ -754,4 +754,5 @@ sys_call_table:
 	.long sys_open_by_handle_at
 	.long sys_clock_adjtime
 	.long sys_syncfs
+	.long sys_setns
 
-- 
1.7.5.1.217.g4e3aa

Re: [PATCH 7/7] ns: Wire up the setns system call

[Geert Uytterhoeven]

On Sat, May 7, 2011 at 16:09, Eric W. Biederman <ebiederm@xmission.com> wrote:
> Geert Uytterhoeven <geert@linux-m68k.org> writes:
>
>> On Sat, May 7, 2011 at 04:25, Eric W. Biederman <ebiederm@xmission.com> wrote:
>>>  arch/m68k/include/asm/unistd.h         |    3 ++-
>>>  arch/m68k/kernel/syscalltable.S        |    1 +
>>
>> As the unified syscalltable for m68k/m68knommu is not yet in mainline
>> (planned for
>> 2.6.40), you should also add it to arch/m68k/kernel/entry_mm.S.
>>
>> Gr{oetje,eeting}s,
>
> Like so?
>
> From c06a03281d944ed36e2da02f5374ec6c650e4988 Mon Sep 17 00:00:00 2001
> From: "Eric W. Biederman" <ebiederm@xmission.com>
> Date: Sat, 7 May 2011 07:00:24 -0700
> Subject: [PATCH] m68knommu: Wire up the setns system call
>
> It seems I overlooked m68knommu where I wired up this syscall.

You overlooked m68k with MMU. syscalltable.s is used by m68knommu.

> Reported-by:  Geert Uytterhoeven <geert@linux-m68k.org>
> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
> ---
>  arch/m68k/kernel/entry_mm.S |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
>
> diff --git a/arch/m68k/kernel/entry_mm.S b/arch/m68k/kernel/entry_mm.S
> index 1359ee6..e048015 100644
> --- a/arch/m68k/kernel/entry_mm.S
> +++ b/arch/m68k/kernel/entry_mm.S
> @@ -754,4 +754,5 @@ sys_call_table:
>        .long sys_open_by_handle_at
>        .long sys_clock_adjtime
>        .long sys_syncfs
> +       .long sys_setns

Yep.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH 7/7] ns: Wire up the setns system call

[Mike Frysinger]

On Fri, May 6, 2011 at 22:25, Eric W. Biederman wrote:
> v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
> v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
> v4: Moved wiring up of the system call to another patch
> v5: ported to v2.6.39-rc6
>
>  arch/blackfin/include/asm/unistd.h     |    3 ++-
>  arch/blackfin/mach-common/entry.S      |    1 +

Acked-by: Mike Frysinger <vapier@gentoo.org>
-mike

Re: [PATCH 7/7] ns: Wire up the setns system call

[James Bottomley]

On Fri, 2011-05-06 at 19:25 -0700, Eric W. Biederman wrote:
> v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
> v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
> v4: Moved wiring up of the system call to another patch
> v5: ported to v2.6.39-rc6
> 
> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

We already have several syscalls queued up for parisc:

http://git.kernel.org/?p=linux/kernel/git/jejb/parisc-2.6.git;a=shortlog;h=refs/heads/misc

So if you could make this patch over them (or over linux-next), that
would help the merge process.

Thanks,

James

Re: [PATCH 7/7] ns: Wire up the setns system call

[Eric W. Biederman]

James Bottomley <James.Bottomley@HansenPartnership.com> writes:

> On Fri, 2011-05-06 at 19:25 -0700, Eric W. Biederman wrote:
>> v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
>> v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
>> v4: Moved wiring up of the system call to another patch
>> v5: ported to v2.6.39-rc6
>> 
>> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
>
> We already have several syscalls queued up for parisc:
>
> http://git.kernel.org/?p=linux/kernel/git/jejb/parisc-2.6.git;a=shortlog;h=refs/heads/misc
>
> So if you could make this patch over them (or over linux-next), that
> would help the merge process.

I will take a look. I was rather pleasantly surprised that no other
system call conflicts had shown up before now.

This is unfortunately one of those areas where it is almost impossible
to avoid conflicts.

Do you know if there is any chance that the parisc tree might get
rebased or anything horrible like that?

If not I think I will just pull the hunk of the parisc tree with the syscalls
e38f5b745075828ac51b12c8c95c85a7be4a3ec7...2e7bad5f34b5beed47542490c760ed26574e38ba
into my tree so I don't have to worry about merge order.

Eric

Re: [PATCH 7/7] ns: Wire up the setns system call

[James Bottomley]

On Sat, 2011-05-07 at 19:19 -0700, Eric W. Biederman wrote:
> James Bottomley <James.Bottomley@HansenPartnership.com> writes:
> 
> > On Fri, 2011-05-06 at 19:25 -0700, Eric W. Biederman wrote:
> >> v2: Most of the architecture support added by Daniel Lezcano <dlezcano@fr.ibm.com>
> >> v3: ported to v2.6.36-rc4 by: Eric W. Biederman <ebiederm@xmission.com>
> >> v4: Moved wiring up of the system call to another patch
> >> v5: ported to v2.6.39-rc6
> >> 
> >> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
> >
> > We already have several syscalls queued up for parisc:
> >
> > http://git.kernel.org/?p=linux/kernel/git/jejb/parisc-2.6.git;a=shortlog;h=refs/heads/misc
> >
> > So if you could make this patch over them (or over linux-next), that
> > would help the merge process.
> 
> I will take a look. I was rather pleasantly surprised that no other
> system call conflicts had shown up before now.
> 
> This is unfortunately one of those areas where it is almost impossible
> to avoid conflicts.
> 
> Do you know if there is any chance that the parisc tree might get
> rebased or anything horrible like that?

It shouldn't unless one of the wire ups is wrong and I have to replace
it, but I think the possibility of that will be minute.

> If not I think I will just pull the hunk of the parisc tree with the syscalls
> e38f5b745075828ac51b12c8c95c85a7be4a3ec7...2e7bad5f34b5beed47542490c760ed26574e38ba
> into my tree so I don't have to worry about merge order.

Yes, that should work fine.

James

Re: [PATCH 1/7] ns: proc files for namespace naming policy.

[Daniel Lezcano]

On 05/07/2011 04:24 AM, Eric W. Biederman wrote:
> Create files under /proc/<pid>/ns/ to allow controlling the
> namespaces of a process.
>
> This addresses three specific problems that can make namespaces hard to
> work with.
> - Namespaces require a dedicated process to pin them in memory.
> - It is not possible to use a namespace unless you are the child
>    of the original creator.
> - Namespaces don't have names that userspace can use to talk about
>    them.
>
> The namespace files under /proc/<pid>/ns/ can be opened and the
> file descriptor can be used to talk about a specific namespace, and
> to keep the specified namespace alive.
>
> A namespace can be kept alive by either holding the file descriptor
> open or bind mounting the file someplace else.  aka:
> mount --bind /proc/self/ns/net /some/filesystem/path
> mount --bind /proc/self/fd/<N>  /some/filesystem/path
>
> This allows namespaces to be named with userspace policy.
>
> It requires additional support to make use of these filedescriptors
> and that will be comming in the following patches.
>
> Signed-off-by: Eric W. Biederman<ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>

Re: [PATCH 1/7] ns: proc files for namespace naming policy.

[Nathan Lynch]

Hi Eric,

A few comments on your patch set.


On Fri, 2011-05-06 at 19:24 -0700, Eric W. Biederman wrote:
> diff --git a/fs/proc/inode.c b/fs/proc/inode.c
> index d15aa1b..74b48cf 100644
> --- a/fs/proc/inode.c
> +++ b/fs/proc/inode.c
> @@ -28,6 +28,7 @@ static void proc_evict_inode(struct inode *inode)
>  {
>  	struct proc_dir_entry *de;
>  	struct ctl_table_header *head;
> +	const struct proc_ns_operations *ns_ops;
>  
>  	truncate_inode_pages(&inode->i_data, 0);
>  	end_writeback(inode);
> @@ -44,6 +45,10 @@ static void proc_evict_inode(struct inode *inode)
>  		rcu_assign_pointer(PROC_I(inode)->sysctl, NULL);
>  		sysctl_head_put(head);
>  	}
> +	/* Release any associated namespace */
> +	ns_ops = PROC_I(inode)->ns_ops;
> +	if (ns_ops && ns_ops->put)
> +		ns_ops->put(PROC_I(inode)->ns);

Is it ever valid for ns_ops->put to be null?  If not, I suggest removing
the check.


> diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
> new file mode 100644
> index 0000000..6ae9f07
> --- /dev/null
> +++ b/fs/proc/namespaces.c

...

> +static struct dentry *proc_ns_dir_lookup(struct inode *dir,
> +				struct dentry *dentry, struct nameidata *nd)
> +{
> +	struct dentry *error;
> +	struct task_struct *task = get_proc_task(dir);
> +	const struct proc_ns_operations **entry, **last;
> +	unsigned int len = dentry->d_name.len;
> +
> +	error = ERR_PTR(-ENOENT);
> +
> +	if (!task)
> +		goto out_no_task;
> +
> +	error = ERR_PTR(-EPERM);
> +	if (!ptrace_may_access(task, PTRACE_MODE_READ))
> +		goto out;
> +
> +	last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
> +	for (entry = ns_entries; entry <= last; entry++) {
> +		if (strlen((*entry)->name) != len)
> +			continue;
> +		if (!memcmp(dentry->d_name.name, (*entry)->name, len))
> +			break;
> +	}
> +	if (entry > last)
> +		goto out;

This returns EPERM when it should return ENOENT?


> +
> +	error = proc_ns_instantiate(dir, dentry, task, *entry);
> +out:
> +	put_task_struct(task);
> +out_no_task:
> +	return error;
> +}

...

> --- a/include/linux/proc_fs.h
> +++ b/include/linux/proc_fs.h
> @@ -250,6 +257,15 @@ kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
>  extern void kclist_add(struct kcore_list *, void *, size_t, int type);
>  #endif
>  
> +struct nsproxy;
> +struct proc_ns_operations {
> +	const char *name;
> +	int type;
> +	void *(*get)(struct task_struct *task);
> +	void (*put)(void *ns);
> +	int (*install)(struct nsproxy *nsproxy, void *ns);
> +};
> +
>  union proc_op {
>  	int (*proc_get_link)(struct inode *, struct path *);
>  	int (*proc_read)(struct task_struct *task, char *page);
> @@ -268,6 +284,8 @@ struct proc_inode {
>  	struct proc_dir_entry *pde;
>  	struct ctl_table_header *sysctl;
>  	struct ctl_table *sysctl_entry;
> +	void *ns;
> +	const struct proc_ns_operations *ns_ops;
>  	struct inode vfs_inode;
>  };

Not that I have any better ideas, but it seems a bit undesirable to
increase the size of proc_inode for this one purpose.

Re: [PATCH 1/7] ns: proc files for namespace naming policy.

[Eric W. Biederman]

Nathan Lynch <ntl@pobox.com> writes:

> Hi Eric,
>
> A few comments on your patch set.
>
>
> On Fri, 2011-05-06 at 19:24 -0700, Eric W. Biederman wrote:
>> diff --git a/fs/proc/inode.c b/fs/proc/inode.c
>> index d15aa1b..74b48cf 100644
>> --- a/fs/proc/inode.c
>> +++ b/fs/proc/inode.c
>> @@ -28,6 +28,7 @@ static void proc_evict_inode(struct inode *inode)
>>  {
>>  	struct proc_dir_entry *de;
>>  	struct ctl_table_header *head;
>> +	const struct proc_ns_operations *ns_ops;
>>  
>>  	truncate_inode_pages(&inode->i_data, 0);
>>  	end_writeback(inode);
>> @@ -44,6 +45,10 @@ static void proc_evict_inode(struct inode *inode)
>>  		rcu_assign_pointer(PROC_I(inode)->sysctl, NULL);
>>  		sysctl_head_put(head);
>>  	}
>> +	/* Release any associated namespace */
>> +	ns_ops = PROC_I(inode)->ns_ops;
>> +	if (ns_ops && ns_ops->put)
>> +		ns_ops->put(PROC_I(inode)->ns);
>
> Is it ever valid for ns_ops->put to be null?  If not, I suggest removing
> the check.
>
>
>> diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
>> new file mode 100644
>> index 0000000..6ae9f07
>> --- /dev/null
>> +++ b/fs/proc/namespaces.c
>
> ...
>
>> +static struct dentry *proc_ns_dir_lookup(struct inode *dir,
>> +				struct dentry *dentry, struct nameidata *nd)
>> +{
>> +	struct dentry *error;
>> +	struct task_struct *task = get_proc_task(dir);
>> +	const struct proc_ns_operations **entry, **last;
>> +	unsigned int len = dentry->d_name.len;
>> +
>> +	error = ERR_PTR(-ENOENT);
>> +
>> +	if (!task)
>> +		goto out_no_task;
>> +
>> +	error = ERR_PTR(-EPERM);
>> +	if (!ptrace_may_access(task, PTRACE_MODE_READ))
>> +		goto out;
>> +
>> +	last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
>> +	for (entry = ns_entries; entry <= last; entry++) {
>> +		if (strlen((*entry)->name) != len)
>> +			continue;
>> +		if (!memcmp(dentry->d_name.name, (*entry)->name, len))
>> +			break;
>> +	}
>> +	if (entry > last)
>> +		goto out;
>
> This returns EPERM when it should return ENOENT?

Good catch.

And fixed now.

>>  union proc_op {
>>  	int (*proc_get_link)(struct inode *, struct path *);
>>  	int (*proc_read)(struct task_struct *task, char *page);
>> @@ -268,6 +284,8 @@ struct proc_inode {
>>  	struct proc_dir_entry *pde;
>>  	struct ctl_table_header *sysctl;
>>  	struct ctl_table *sysctl_entry;
>> +	void *ns;
>> +	const struct proc_ns_operations *ns_ops;
>>  	struct inode vfs_inode;
>>  };
>
> Not that I have any better ideas, but it seems a bit undesirable to
> increase the size of proc_inode for this one purpose.

Of the options I could think of this was the cleanest, and proc_inode
is just a caching data structure which means that the effect should be
comparatively minimal.

That said I won't oppose a change at some point to reduce the
proc_inode, there are a lot of fields that are not used for most proc
entries.

Eric

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Alex Bligh]

--On 6 May 2011 19:23:29 -0700 "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> 
wrote:

> This patchset addresses the user interface limitations by introducing
> proc files you can open to get file descriptors that keep alive and
> refer to your a tasks namespaces.  Those file descriptors can be passed
> to the new setns system call or the NET_NS_FD argument in netlink
> messages.

This is conceptually very interesting. I am one of those people you
describe with a routing daemon (or more accurately a wrapper around
existing daemons) that does the unshare() and keeps the network
alive. It also has a control socket etc.

You say:
> This addresses three specific problems that can make namespaces hard to
> work with.
> - Namespaces require a dedicated process to pin them in memory.
> - It is not possible to use a namespace unless you are the child
>   of the original creator.
> - Namespaces don't have names that userspace can use to talk about
>   them.

At least for me, the best way to solve the second blob would be to
be able to unshare to an existing namespace. That way I would be able
to run a daemon (without modification) in a pre-existing namespace.
The user interface here would just be an option to 'unshare'. I
don't think your patch allows this, does it? Right now I'm effectively
doing that by causing the pid concerned to fork() and do my bidding,
but that is far from perfect.

As a secondary issue, ever without your patch, it would be really
useful to be able to read from userspace the current network namespace.
(i.e. the pid concerned, or 1 if not unshared). I would like to
simply modify a routing daemon's init script so it doesn't start
if in the host, e.g. at the top:
  [ `cat /proc/.../networknamespace` eq 1 ] && exit 0

-- 
Alex Bligh

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Alex Bligh]

--On 6 May 2011 19:23:29 -0700 "Eric W. Biederman" <ebiederm@xmission.com> 
wrote:

> This patchset addresses the user interface limitations by introducing
> proc files you can open to get file descriptors that keep alive and
> refer to your a tasks namespaces.  Those file descriptors can be passed
> to the new setns system call or the NET_NS_FD argument in netlink
> messages.

This is conceptually very interesting. I am one of those people you
describe with a routing daemon (or more accurately a wrapper around
existing daemons) that does the unshare() and keeps the network
alive. It also has a control socket etc.

You say:
> This addresses three specific problems that can make namespaces hard to
> work with.
> - Namespaces require a dedicated process to pin them in memory.
> - It is not possible to use a namespace unless you are the child
>   of the original creator.
> - Namespaces don't have names that userspace can use to talk about
>   them.

At least for me, the best way to solve the second blob would be to
be able to unshare to an existing namespace. That way I would be able
to run a daemon (without modification) in a pre-existing namespace.
The user interface here would just be an option to 'unshare'. I
don't think your patch allows this, does it? Right now I'm effectively
doing that by causing the pid concerned to fork() and do my bidding,
but that is far from perfect.

As a secondary issue, ever without your patch, it would be really
useful to be able to read from userspace the current network namespace.
(i.e. the pid concerned, or 1 if not unshared). I would like to
simply modify a routing daemon's init script so it doesn't start
if in the host, e.g. at the top:
  [ `cat /proc/.../networknamespace` eq 1 ] && exit 0

-- 
Alex Bligh

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Eric W. Biederman]

Alex Bligh <alex@alex.org.uk> writes:

> --On 6 May 2011 19:23:29 -0700 "Eric W. Biederman" <ebiederm@xmission.com>
> wrote:
>
>> This patchset addresses the user interface limitations by introducing
>> proc files you can open to get file descriptors that keep alive and
>> refer to your a tasks namespaces.  Those file descriptors can be passed
>> to the new setns system call or the NET_NS_FD argument in netlink
>> messages.
>
> This is conceptually very interesting. I am one of those people you
> describe with a routing daemon (or more accurately a wrapper around
> existing daemons) that does the unshare() and keeps the network
> alive. It also has a control socket etc.
>
> You say:
>> This addresses three specific problems that can make namespaces hard to
>> work with.
>> - Namespaces require a dedicated process to pin them in memory.
>> - It is not possible to use a namespace unless you are the child
>>   of the original creator.
>> - Namespaces don't have names that userspace can use to talk about
>>   them.
>
> At least for me, the best way to solve the second blob would be to
> be able to unshare to an existing namespace. That way I would be able
> to run a daemon (without modification) in a pre-existing namespace.
> The user interface here would just be an option to 'unshare'. I
> don't think your patch allows this, does it?  Right now I'm effectively
> doing that by causing the pid concerned to fork() and do my bidding,
> but that is far from perfect.

You are essentially describing my setns system call.

> As a secondary issue, ever without your patch, it would be really
> useful to be able to read from userspace the current network namespace.
> (i.e. the pid concerned, or 1 if not unshared). I would like to
> simply modify a routing daemon's init script so it doesn't start
> if in the host, e.g. at the top:
>  [ `cat /proc/.../networknamespace` eq 1 ] && exit 0

You can read the processes network namespace by opening
/proc/<pid>/ns/net.  Unfortunately comparing the network
namespaces for identity is another matter.  You will probably
be better off simply forcing the routing daemon to start
in the desired network namespace in it's initscript.

For purposes of clarity please have a look at my work in
progress patch for iproute2.  This demonstrates how I expect
userspace to work in a multi-network namespace world.

Eric


From f773bd66c2e31e1ac55b65ce5bc2c17f8845ce5c Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Fri, 6 May 2011 00:01:45 -0700
Subject: [PATCH] iproute2:  Add processless netnwork namespace support.

The goal of this code change is to implement a mechanism
such that it is simple to work with a kernel that is
using multiple network namespaces at once.

This comes in handy for interacting with vpns where
there may be rfc1918 address overlaps, and different
policies default routes, name servers and the like.

Configuration specific to a network namespace that
would ordinarily be stored under /etc/ is stored under
/etc/netns/<name>.  For example if the dns server
configuration is different for your vpn you would
create a file /etc/netns/myvpn/resolv.conf.

File descriptors that can be used to manipulate a
network namespace can be created by opening
/var/run/netns/<NAME>.

This adds the following commands to iproute.
ip netns add NAME
ip netns delete NAME
ip netns monitor
ip netns list
ip netns exec NAME cmd ....
ip link set DEV netns NAME

ip netns exec exists to cater the vast majority of programs
that only know how to operate in a single network namespace.
ip netns exec changes the default network namespace, creates
a new mount namespace, remounts /sys and bind mounts netns
specific configuration files to their standard locations.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 include/linux/if_link.h |    1 +
 ip/Makefile             |    2 +-
 ip/ip.c                 |    4 +-
 ip/ip_common.h          |    2 +
 ip/iplink.c             |    8 +-
 ip/ipnetns.c            |  320 +++++++++++++++++++++++++++++++++++++++++++++++
 man/man8/ip.8           |   56 ++++++++
 7 files changed, 389 insertions(+), 4 deletions(-)
 create mode 100644 ip/ipnetns.c

diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index e4a3a2d..304c44f 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -136,6 +136,7 @@ enum {
 	IFLA_PORT_SELF,
 	IFLA_AF_SPEC,
 	IFLA_GROUP,		/* Group the device belongs to */
+	IFLA_NET_NS_FD,
 	__IFLA_MAX
 };
 
diff --git a/ip/Makefile b/ip/Makefile
index 6054e8a..2ee4e7c 100644
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -1,4 +1,4 @@
-IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o \
+IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
     rtm_map.o iptunnel.o ip6tunnel.o tunnel.o ipneigh.o ipntable.o iplink.o \
     ipmaddr.o ipmonitor.o ipmroute.o ipprefix.o iptuntap.o \
     ipxfrm.o xfrm_state.o xfrm_policy.o xfrm_monitor.o \
diff --git a/ip/ip.c b/ip/ip.c
index b127d57..7f0c468 100644
--- a/ip/ip.c
+++ b/ip/ip.c
@@ -44,7 +44,8 @@ static void usage(void)
 "Usage: ip [ OPTIONS ] OBJECT { COMMAND | help }\n"
 "       ip [ -force ] -batch filename\n"
 "where  OBJECT := { link | addr | addrlabel | route | rule | neigh | ntable |\n"
-"                   tunnel | tuntap | maddr | mroute | mrule | monitor | xfrm }\n"
+"                   tunnel | tuntap | maddr | mroute | mrule | monitor | xfrm |\n"
+"                   netns }\n"
 "       OPTIONS := { -V[ersion] | -s[tatistics] | -d[etails] | -r[esolve] |\n"
 "                    -f[amily] { inet | inet6 | ipx | dnet | link } |\n"
 "                    -l[oops] { maximum-addr-flush-attempts } |\n"
@@ -80,6 +81,7 @@ static const struct cmd {
 	{ "xfrm",	do_xfrm },
 	{ "mroute",	do_multiroute },
 	{ "mrule",	do_multirule },
+	{ "netns",	do_netns },
 	{ "help",	do_help },
 	{ 0 }
 };
diff --git a/ip/ip_common.h b/ip/ip_common.h
index a114186..5e5fb76 100644
--- a/ip/ip_common.h
+++ b/ip/ip_common.h
@@ -38,6 +38,7 @@ extern int do_ipmonitor(int argc, char **argv);
 extern int do_multiaddr(int argc, char **argv);
 extern int do_multiroute(int argc, char **argv);
 extern int do_multirule(int argc, char **argv);
+extern int do_netns(int argc, char **argv);
 extern int do_xfrm(int argc, char **argv);
 
 static inline int rtm_get_table(struct rtmsg *r, struct rtattr **tb)
@@ -64,6 +65,7 @@ struct link_util
 };
 
 struct link_util *get_link_kind(const char *kind);
+int get_netns_fd(const char *name);
 
 #ifndef	INFINITY_LIFE_TIME
 #define     INFINITY_LIFE_TIME      0xFFFFFFFFU
diff --git a/ip/iplink.c b/ip/iplink.c
index 48c0254..e5325a6 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -67,6 +67,7 @@ void iplink_usage(void)
 	fprintf(stderr, "	                  [ broadcast LLADDR ]\n");
 	fprintf(stderr, "	                  [ mtu MTU ]\n");
 	fprintf(stderr, "	                  [ netns PID ]\n");
+	fprintf(stderr, "	                  [ netns NAME ]\n");
 	fprintf(stderr, "			  [ alias NAME ]\n");
 	fprintf(stderr, "	                  [ vf NUM [ mac LLADDR ]\n");
 	fprintf(stderr, "				   [ vlan VLANID [ qos VLAN-QOS ] ]\n");
@@ -304,9 +305,12 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req,
                         NEXT_ARG();
                         if (netns != -1)
                                 duparg("netns", *argv);
-                        if (get_integer(&netns, *argv, 0))
+			if ((netns = get_netns_fd(*argv)) >= 0)
+				addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_FD, &netns, 4);
+			else if (get_integer(&netns, *argv, 0) == 0)
+				addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_PID, &netns, 4);
+			else
                                 invarg("Invalid \"netns\" value\n", *argv);
-                        addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_PID, &netns, 4);
 		} else if (strcmp(*argv, "multicast") == 0) {
 			NEXT_ARG();
 			req->i.ifi_change |= IFF_MULTICAST;
diff --git a/ip/ipnetns.c b/ip/ipnetns.c
new file mode 100644
index 0000000..efb7fd2
--- /dev/null
+++ b/ip/ipnetns.c
@@ -0,0 +1,320 @@
+#define _ATFILE_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/inotify.h>
+#include <sys/mount.h>
+#include <sys/param.h>
+#include <stdio.h>
+#include <string.h>
+#include <sched.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include "utils.h"
+#include "ip_common.h"
+
+#define NETNS_RUN_DIR "/var/run/netns"
+#define NETNS_ETC_DIR "/etc/netns"
+
+#ifdef __x86_64__
+#define PRIVATE_SYS_setns 307
+#endif
+
+#ifdef __i386__
+#define PRIVATE_SYS_setns 345
+#endif
+
+#ifndef SYS_setns
+#define SYS_setns PRIVATE_SYS_setns
+#endif
+
+#ifndef CLONE_NEWNET
+#define CLONE_NEWNET 0x40000000	/* New network namespace (lo, device, names sockets, etc) */
+#endif
+
+#ifndef MNT_DETACH
+#define MNT_DETACH	0x00000002	/* Just detach from the tree */
+#endif /* MNT_DETACH */
+
+
+static int setns(int fd, int nstype)
+{
+	return syscall(SYS_setns, fd, nstype);
+}
+
+static int touch(const char *path, mode_t mode)
+{
+	int fd;
+	fd = open(path, O_RDONLY|O_CREAT, mode);
+	if (fd < 0)
+		return -1;
+	close(fd);
+	return 0;
+}
+
+static void usage(void) __attribute__((noreturn));
+
+static void usage(void)
+{
+	fprintf(stderr, "Usage: ip netns list\n");
+	fprintf(stderr, "       ip netns add NAME\n");
+	fprintf(stderr, "       ip netns delete NAME\n");
+	fprintf(stderr, "       ip netns exec NAME cmd ...\n");
+	fprintf(stderr, "       ip netns monitor\n");
+	exit(-1);
+}
+
+int get_netns_fd(const char *name)
+{
+	char pathbuf[MAXPATHLEN];
+	const char *path, *ptr;
+
+	path = name;
+	ptr = strchr(name, '/');
+	if (!ptr) {
+		snprintf(pathbuf, sizeof(pathbuf), "%s/%s",
+			NETNS_RUN_DIR, name );
+		path = pathbuf;
+	}
+	return open(path, O_RDONLY);
+}
+
+static int netns_list(int argc, char **argv)
+{
+	struct dirent *entry;
+	DIR *dir;
+
+	dir = opendir(NETNS_RUN_DIR);
+	if (!dir)
+		return 0;
+
+	while ((entry = readdir(dir)) != NULL) {
+		if (strcmp(entry->d_name, ".") == 0)
+			continue;
+		if (strcmp(entry->d_name, "..") == 0)
+			continue;
+		printf("%s\n", entry->d_name);
+	}
+	closedir(dir);
+	return 0;
+}
+
+static void bind_etc(const char *name)
+{
+	char etc_netns_path[MAXPATHLEN];
+	char netns_name[MAXPATHLEN];
+	char etc_name[MAXPATHLEN];
+	struct dirent *entry;
+	DIR *dir;
+
+	snprintf(etc_netns_path, sizeof(etc_netns_path), "%s/%s", NETNS_ETC_DIR, name);
+	dir = opendir(etc_netns_path);
+	if (!dir)
+		return;
+
+	while ((entry = readdir(dir)) != NULL) {
+		if (strcmp(entry->d_name, ".") == 0)
+			continue;
+		if (strcmp(entry->d_name, "..") == 0)
+			continue;
+		snprintf(netns_name, sizeof(netns_name), "%s/%s", etc_netns_path, entry->d_name);
+		snprintf(etc_name, sizeof(etc_name), "/etc/%s", entry->d_name);
+		if (mount(netns_name, etc_name, "none", MS_BIND, NULL) < 0) {
+			fprintf(stderr, "Bind %s -> %s failed: %s\n",
+				netns_name, etc_name, strerror(errno));
+		}
+	}
+	closedir(dir);
+}
+
+static int netns_exec(int argc, char **argv)
+{
+	/* Setup the proper environment for apps that are not netns
+	 * aware, and execute a program in that environment.
+	 */
+	const char *name, *cmd;
+	char net_path[MAXPATHLEN];
+	int netns;
+
+	if (argc < 1) {
+		fprintf(stderr, "No netns name specified\n");
+		return -1;
+	}
+	if (argc < 2) {
+		fprintf(stderr, "No cmd specified\n");
+		return -1;
+	}
+	name = argv[0];
+	cmd = argv[1];
+	snprintf(net_path, sizeof(net_path), "%s/%s", NETNS_RUN_DIR, name);
+	netns = open(net_path, O_RDONLY);
+	if (netns < 0) {
+		fprintf(stderr, "Cannot open network namespace: %s\n",
+			strerror(errno));
+		return -1;
+	}
+	if (setns(netns, CLONE_NEWNET) < 0) {
+		fprintf(stderr, "seting the network namespace failed: %s\n",
+			strerror(errno));
+		return -1;
+	}
+
+	if (unshare(CLONE_NEWNS) < 0) {
+		fprintf(stderr, "unshare failed: %s\n", strerror(errno));
+		return -1;
+	}
+	/* Mount a version of /sys that describes the network namespace */
+	if (umount2("/sys", MNT_DETACH) < 0) {
+		fprintf(stderr, "umount of /sys failed: %s\n", strerror(errno));
+		return -1;
+	}
+	if (mount(name, "/sys", "sysfs", 0, NULL) < 0) {
+		fprintf(stderr, "mount of /sys failed: %s\n",strerror(errno));
+		return -1;
+	}
+
+	/* Setup bind mounts for config files in /etc */
+	bind_etc(name);
+
+	if (execvp(cmd, argv + 1)  < 0)
+		fprintf(stderr, "exec of %s failed: %s\n",
+			cmd, strerror(errno));
+	exit(-1);
+}
+
+static int netns_delete(int argc, char **argv)
+{
+	const char *name;
+	char netns_path[MAXPATHLEN];
+
+	if (argc < 1) {
+		fprintf(stderr, "No netns name specified\n");
+		return -1;
+	}
+
+	name = argv[0];
+	snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, name);
+	umount2(netns_path, MNT_DETACH);
+	if (unlink(netns_path) < 0) {
+		fprintf(stderr, "Cannot remove %s: %s\n",
+			netns_path, strerror(errno));
+		return -1;
+	}
+	return 0;
+}
+
+static int netns_add(int argc, char **argv)
+{
+	/* This function creates a new network namespace and
+	 * a new mount namespace and bind them into a well known
+	 * location in the filesystem based on the name provided.
+	 *
+	 * The mount namespace is created so that any necessary
+	 * userspace tweaks like remounting /sys, or bind mounting
+	 * a new /etc/resolv.conf can be shared between uers.
+	 */
+	char netns_path[MAXPATHLEN];
+	const char *name;
+
+	if (argc < 1) {
+		fprintf(stderr, "No netns name specified\n");
+		return -1;
+	}
+	name = argv[0];
+
+	snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, name);
+
+	/* Create the base netns directory if it doesn't exist */
+	mkdir(NETNS_RUN_DIR, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
+
+	/* Create the filesystem state */
+	if (touch(netns_path, 0) < 0) {
+		fprintf(stderr, "Could not create %s: %s\n",
+			netns_path, strerror(errno));
+		goto out_delete;
+	}
+	if (unshare(CLONE_NEWNET) < 0) {
+		fprintf(stderr, "Failed to create a new network namespace: %s\n",
+			strerror(errno));
+		goto out_delete;
+	}
+
+	/* Bind the netns last so I can watch for it */
+	if (mount("/proc/self/ns/net", netns_path, "none", MS_BIND, NULL) < 0) {
+		fprintf(stderr, "Bind /proc/self/ns/net -> %s failed: %s\n",
+			netns_path, strerror(errno));
+		goto out_delete;
+	}
+	return 0;
+out_delete:
+	netns_delete(argc, argv);
+	exit(-1);
+	return -1;
+}
+
+
+static int netns_monitor(int argc, char **argv)
+{
+	char buf[4096];
+	struct inotify_event *event;
+	int fd;
+	fd = inotify_init();
+	if (fd < 0) {
+		fprintf(stderr, "inotify_init failed: %s\n",
+			strerror(errno));
+		return -1;
+	}
+	if (inotify_add_watch(fd, NETNS_RUN_DIR, IN_CREATE | IN_DELETE) < 0) {
+		fprintf(stderr, "inotify_add_watch failed: %s\n",
+			strerror(errno));
+		return -1;
+	}
+	for(;;) {
+		ssize_t len = read(fd, buf, sizeof(buf));
+		if (len < 0) {
+			fprintf(stderr, "read failed: %s\n",
+				strerror(errno));
+			return -1;
+		}
+		for (event = (struct inotify_event *)buf;
+		     (char *)event < &buf[len];
+		     event = (struct inotify_event *)((char *)event + sizeof(*event) + event->len)) {
+			if (event->mask & IN_CREATE)
+				printf("add %s\n", event->name);
+			if (event->mask & IN_DELETE)
+				printf("delete %s\n", event->name);
+		}
+	}
+	return 0;
+}
+
+int do_netns(int argc, char **argv)
+{
+	if (argc < 1)
+		return netns_list(0, NULL);
+
+	if ((matches(*argv, "list") == 0) || (matches(*argv, "show") == 0) ||
+	    (matches(*argv, "lst") == 0))
+		return netns_list(argc-1, argv+1);
+
+	if (matches(*argv, "help") == 0)
+		usage();
+
+	if (matches(*argv, "add") == 0)
+		return netns_add(argc-1, argv+1);
+
+	if (matches(*argv, "delete") == 0)
+		return netns_delete(argc-1, argv+1);
+
+	if (matches(*argv, "exec") == 0)
+		return netns_exec(argc-1, argv+1);
+
+	if (matches(*argv, "monitor") == 0)
+		return netns_monitor(argc-1, argv+1);
+
+	fprintf(stderr, "Command \"%s\" is unknown, try \"ip netns help\".\n", *argv);
+	exit(-1);
+}
diff --git a/man/man8/ip.8 b/man/man8/ip.8
index c5248ef..1935dc5 100644
--- a/man/man8/ip.8
+++ b/man/man8/ip.8
@@ -85,6 +85,9 @@ ip \- show / manipulate routing, devices, policy routing and tunnels
 .B  netns
 .IR PID " |"
 .br
+.B  netns
+.IR NETNSNAME " |"
+.br
 .B alias
 .IR NAME  " |"
 .br
@@ -162,6 +165,17 @@ tentative " | " deprecated " | " dadfailed " | " temporary " ]"
 .BR "ip addrlabel" " { " list " | " flush " }"
 
 .ti -8
+.BR "ip netns" " { " list " | " monitor " } "
+
+.ti -8
+.BR "ip netns" " { " add " | " delete " } "
+.I NETNSNAME
+
+.ti -8
+.BR "ip netns exec "
+.I NETNSNAME command ...
+
+.ti -8
 .BR "ip route" " { "
 .BR list " | " flush " } "
 .I  SELECTOR
@@ -1006,6 +1020,11 @@ move the device to the network namespace associated with the process
 .IR "PID".
 
 .TP
+.BI netns " NETNSNAME"
+move the device to the network namespace associated with name
+.IR "NETNSNAME".
+
+.TP
 .BI alias " NAME"
 give the device a symbolic name for easy reference.
 
@@ -2470,6 +2489,43 @@ at any time.
 It prepends the history with the state snapshot dumped at the moment
 of starting.
 
+.SH ip netns - process network namespace management
+
+A network namespace is logically another copy of the network stack,
+with it's own routes, firewall rules, and network devices.
+
+By convention a named network namespace is an object at
+.BR "/var/run/netns/" NAME
+that can be opened.  The file descriptor resulting from opening
+.BR "/var/run/netns/" NAME 
+refers to the specified network namespace.  Holding that file
+descriptor open keeps the network namespace alive.  The file
+descriptor can be used with the
+.B setns(2)
+system call to change the network namespace associated with a task.
+
+The convention for network namespace aware applications is to look
+for global network configuration files first in
+.BR "/etc/netns/" NAME "/"
+then in
+.BR "/etc/".
+For example, if you want a different version of
+.BR /etc/resolv.conf
+for a network namespace used to isolate your vpn you would name it
+.BR /etc/netns/myvpn/resolv.conf.
+
+.B ip netns exec
+automates handling of this configuration, file convention for network
+namespace unaware applications, by creating a mount namespace and
+bind mounting all of the per network namespace configure files into
+their traditional location in /etc.
+
+.SS ip netns list - show all of the named network namespaces
+.SS ip netns monitor - report when network namespace names are created and destroyed
+.SS ip netns add NAME - create a new named network namespace
+.SS ip netns delete NAME - delete the name of a network namespace
+.SS ip netns exec NAME cmd ... - Run cmd in the named network namespace
+
 .SH ip xfrm - setting xfrm
 xfrm is an IP framework, which can transform format of the datagrams,
 .br
-- 
1.7.5.1.217.g4e3aa

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Eric W. Biederman]

Alex Bligh <alex@alex.org.uk> writes:

> --On 6 May 2011 19:23:29 -0700 "Eric W. Biederman" <ebiederm@xmission.com>
> wrote:
>
>> This patchset addresses the user interface limitations by introducing
>> proc files you can open to get file descriptors that keep alive and
>> refer to your a tasks namespaces.  Those file descriptors can be passed
>> to the new setns system call or the NET_NS_FD argument in netlink
>> messages.
>
> This is conceptually very interesting. I am one of those people you
> describe with a routing daemon (or more accurately a wrapper around
> existing daemons) that does the unshare() and keeps the network
> alive. It also has a control socket etc.
>
> You say:
>> This addresses three specific problems that can make namespaces hard to
>> work with.
>> - Namespaces require a dedicated process to pin them in memory.
>> - It is not possible to use a namespace unless you are the child
>>   of the original creator.
>> - Namespaces don't have names that userspace can use to talk about
>>   them.
>
> At least for me, the best way to solve the second blob would be to
> be able to unshare to an existing namespace. That way I would be able
> to run a daemon (without modification) in a pre-existing namespace.
> The user interface here would just be an option to 'unshare'. I
> don't think your patch allows this, does it?  Right now I'm effectively
> doing that by causing the pid concerned to fork() and do my bidding,
> but that is far from perfect.

You are essentially describing my setns system call.

> As a secondary issue, ever without your patch, it would be really
> useful to be able to read from userspace the current network namespace.
> (i.e. the pid concerned, or 1 if not unshared). I would like to
> simply modify a routing daemon's init script so it doesn't start
> if in the host, e.g. at the top:
>  [ `cat /proc/.../networknamespace` eq 1 ] && exit 0

You can read the processes network namespace by opening
/proc/<pid>/ns/net.  Unfortunately comparing the network
namespaces for identity is another matter.  You will probably
be better off simply forcing the routing daemon to start
in the desired network namespace in it's initscript.

For purposes of clarity please have a look at my work in
progress patch for iproute2.  This demonstrates how I expect
userspace to work in a multi-network namespace world.

Eric


>From f773bd66c2e31e1ac55b65ce5bc2c17f8845ce5c Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Fri, 6 May 2011 00:01:45 -0700
Subject: [PATCH] iproute2:  Add processless netnwork namespace support.

The goal of this code change is to implement a mechanism
such that it is simple to work with a kernel that is
using multiple network namespaces at once.

This comes in handy for interacting with vpns where
there may be rfc1918 address overlaps, and different
policies default routes, name servers and the like.

Configuration specific to a network namespace that
would ordinarily be stored under /etc/ is stored under
/etc/netns/<name>.  For example if the dns server
configuration is different for your vpn you would
create a file /etc/netns/myvpn/resolv.conf.

File descriptors that can be used to manipulate a
network namespace can be created by opening
/var/run/netns/<NAME>.

This adds the following commands to iproute.
ip netns add NAME
ip netns delete NAME
ip netns monitor
ip netns list
ip netns exec NAME cmd ....
ip link set DEV netns NAME

ip netns exec exists to cater the vast majority of programs
that only know how to operate in a single network namespace.
ip netns exec changes the default network namespace, creates
a new mount namespace, remounts /sys and bind mounts netns
specific configuration files to their standard locations.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 include/linux/if_link.h |    1 +
 ip/Makefile             |    2 +-
 ip/ip.c                 |    4 +-
 ip/ip_common.h          |    2 +
 ip/iplink.c             |    8 +-
 ip/ipnetns.c            |  320 +++++++++++++++++++++++++++++++++++++++++++++++
 man/man8/ip.8           |   56 ++++++++
 7 files changed, 389 insertions(+), 4 deletions(-)
 create mode 100644 ip/ipnetns.c

diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index e4a3a2d..304c44f 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -136,6 +136,7 @@ enum {
 	IFLA_PORT_SELF,
 	IFLA_AF_SPEC,
 	IFLA_GROUP,		/* Group the device belongs to */
+	IFLA_NET_NS_FD,
 	__IFLA_MAX
 };
 
diff --git a/ip/Makefile b/ip/Makefile
index 6054e8a..2ee4e7c 100644
--- a/ip/Makefile
+++ b/ip/Makefile
@@ -1,4 +1,4 @@
-IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o \
+IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o ipnetns.o \
     rtm_map.o iptunnel.o ip6tunnel.o tunnel.o ipneigh.o ipntable.o iplink.o \
     ipmaddr.o ipmonitor.o ipmroute.o ipprefix.o iptuntap.o \
     ipxfrm.o xfrm_state.o xfrm_policy.o xfrm_monitor.o \
diff --git a/ip/ip.c b/ip/ip.c
index b127d57..7f0c468 100644
--- a/ip/ip.c
+++ b/ip/ip.c
@@ -44,7 +44,8 @@ static void usage(void)
 "Usage: ip [ OPTIONS ] OBJECT { COMMAND | help }\n"
 "       ip [ -force ] -batch filename\n"
 "where  OBJECT := { link | addr | addrlabel | route | rule | neigh | ntable |\n"
-"                   tunnel | tuntap | maddr | mroute | mrule | monitor | xfrm }\n"
+"                   tunnel | tuntap | maddr | mroute | mrule | monitor | xfrm |\n"
+"                   netns }\n"
 "       OPTIONS := { -V[ersion] | -s[tatistics] | -d[etails] | -r[esolve] |\n"
 "                    -f[amily] { inet | inet6 | ipx | dnet | link } |\n"
 "                    -l[oops] { maximum-addr-flush-attempts } |\n"
@@ -80,6 +81,7 @@ static const struct cmd {
 	{ "xfrm",	do_xfrm },
 	{ "mroute",	do_multiroute },
 	{ "mrule",	do_multirule },
+	{ "netns",	do_netns },
 	{ "help",	do_help },
 	{ 0 }
 };
diff --git a/ip/ip_common.h b/ip/ip_common.h
index a114186..5e5fb76 100644
--- a/ip/ip_common.h
+++ b/ip/ip_common.h
@@ -38,6 +38,7 @@ extern int do_ipmonitor(int argc, char **argv);
 extern int do_multiaddr(int argc, char **argv);
 extern int do_multiroute(int argc, char **argv);
 extern int do_multirule(int argc, char **argv);
+extern int do_netns(int argc, char **argv);
 extern int do_xfrm(int argc, char **argv);
 
 static inline int rtm_get_table(struct rtmsg *r, struct rtattr **tb)
@@ -64,6 +65,7 @@ struct link_util
 };
 
 struct link_util *get_link_kind(const char *kind);
+int get_netns_fd(const char *name);
 
 #ifndef	INFINITY_LIFE_TIME
 #define     INFINITY_LIFE_TIME      0xFFFFFFFFU
diff --git a/ip/iplink.c b/ip/iplink.c
index 48c0254..e5325a6 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c
@@ -67,6 +67,7 @@ void iplink_usage(void)
 	fprintf(stderr, "	                  [ broadcast LLADDR ]\n");
 	fprintf(stderr, "	                  [ mtu MTU ]\n");
 	fprintf(stderr, "	                  [ netns PID ]\n");
+	fprintf(stderr, "	                  [ netns NAME ]\n");
 	fprintf(stderr, "			  [ alias NAME ]\n");
 	fprintf(stderr, "	                  [ vf NUM [ mac LLADDR ]\n");
 	fprintf(stderr, "				   [ vlan VLANID [ qos VLAN-QOS ] ]\n");
@@ -304,9 +305,12 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req,
                         NEXT_ARG();
                         if (netns != -1)
                                 duparg("netns", *argv);
-                        if (get_integer(&netns, *argv, 0))
+			if ((netns = get_netns_fd(*argv)) >= 0)
+				addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_FD, &netns, 4);
+			else if (get_integer(&netns, *argv, 0) == 0)
+				addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_PID, &netns, 4);
+			else
                                 invarg("Invalid \"netns\" value\n", *argv);
-                        addattr_l(&req->n, sizeof(*req), IFLA_NET_NS_PID, &netns, 4);
 		} else if (strcmp(*argv, "multicast") == 0) {
 			NEXT_ARG();
 			req->i.ifi_change |= IFF_MULTICAST;
diff --git a/ip/ipnetns.c b/ip/ipnetns.c
new file mode 100644
index 0000000..efb7fd2
--- /dev/null
+++ b/ip/ipnetns.c
@@ -0,0 +1,320 @@
+#define _ATFILE_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/inotify.h>
+#include <sys/mount.h>
+#include <sys/param.h>
+#include <stdio.h>
+#include <string.h>
+#include <sched.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <errno.h>
+#include <unistd.h>
+
+#include "utils.h"
+#include "ip_common.h"
+
+#define NETNS_RUN_DIR "/var/run/netns"
+#define NETNS_ETC_DIR "/etc/netns"
+
+#ifdef __x86_64__
+#define PRIVATE_SYS_setns 307
+#endif
+
+#ifdef __i386__
+#define PRIVATE_SYS_setns 345
+#endif
+
+#ifndef SYS_setns
+#define SYS_setns PRIVATE_SYS_setns
+#endif
+
+#ifndef CLONE_NEWNET
+#define CLONE_NEWNET 0x40000000	/* New network namespace (lo, device, names sockets, etc) */
+#endif
+
+#ifndef MNT_DETACH
+#define MNT_DETACH	0x00000002	/* Just detach from the tree */
+#endif /* MNT_DETACH */
+
+
+static int setns(int fd, int nstype)
+{
+	return syscall(SYS_setns, fd, nstype);
+}
+
+static int touch(const char *path, mode_t mode)
+{
+	int fd;
+	fd = open(path, O_RDONLY|O_CREAT, mode);
+	if (fd < 0)
+		return -1;
+	close(fd);
+	return 0;
+}
+
+static void usage(void) __attribute__((noreturn));
+
+static void usage(void)
+{
+	fprintf(stderr, "Usage: ip netns list\n");
+	fprintf(stderr, "       ip netns add NAME\n");
+	fprintf(stderr, "       ip netns delete NAME\n");
+	fprintf(stderr, "       ip netns exec NAME cmd ...\n");
+	fprintf(stderr, "       ip netns monitor\n");
+	exit(-1);
+}
+
+int get_netns_fd(const char *name)
+{
+	char pathbuf[MAXPATHLEN];
+	const char *path, *ptr;
+
+	path = name;
+	ptr = strchr(name, '/');
+	if (!ptr) {
+		snprintf(pathbuf, sizeof(pathbuf), "%s/%s",
+			NETNS_RUN_DIR, name );
+		path = pathbuf;
+	}
+	return open(path, O_RDONLY);
+}
+
+static int netns_list(int argc, char **argv)
+{
+	struct dirent *entry;
+	DIR *dir;
+
+	dir = opendir(NETNS_RUN_DIR);
+	if (!dir)
+		return 0;
+
+	while ((entry = readdir(dir)) != NULL) {
+		if (strcmp(entry->d_name, ".") == 0)
+			continue;
+		if (strcmp(entry->d_name, "..") == 0)
+			continue;
+		printf("%s\n", entry->d_name);
+	}
+	closedir(dir);
+	return 0;
+}
+
+static void bind_etc(const char *name)
+{
+	char etc_netns_path[MAXPATHLEN];
+	char netns_name[MAXPATHLEN];
+	char etc_name[MAXPATHLEN];
+	struct dirent *entry;
+	DIR *dir;
+
+	snprintf(etc_netns_path, sizeof(etc_netns_path), "%s/%s", NETNS_ETC_DIR, name);
+	dir = opendir(etc_netns_path);
+	if (!dir)
+		return;
+
+	while ((entry = readdir(dir)) != NULL) {
+		if (strcmp(entry->d_name, ".") == 0)
+			continue;
+		if (strcmp(entry->d_name, "..") == 0)
+			continue;
+		snprintf(netns_name, sizeof(netns_name), "%s/%s", etc_netns_path, entry->d_name);
+		snprintf(etc_name, sizeof(etc_name), "/etc/%s", entry->d_name);
+		if (mount(netns_name, etc_name, "none", MS_BIND, NULL) < 0) {
+			fprintf(stderr, "Bind %s -> %s failed: %s\n",
+				netns_name, etc_name, strerror(errno));
+		}
+	}
+	closedir(dir);
+}
+
+static int netns_exec(int argc, char **argv)
+{
+	/* Setup the proper environment for apps that are not netns
+	 * aware, and execute a program in that environment.
+	 */
+	const char *name, *cmd;
+	char net_path[MAXPATHLEN];
+	int netns;
+
+	if (argc < 1) {
+		fprintf(stderr, "No netns name specified\n");
+		return -1;
+	}
+	if (argc < 2) {
+		fprintf(stderr, "No cmd specified\n");
+		return -1;
+	}
+	name = argv[0];
+	cmd = argv[1];
+	snprintf(net_path, sizeof(net_path), "%s/%s", NETNS_RUN_DIR, name);
+	netns = open(net_path, O_RDONLY);
+	if (netns < 0) {
+		fprintf(stderr, "Cannot open network namespace: %s\n",
+			strerror(errno));
+		return -1;
+	}
+	if (setns(netns, CLONE_NEWNET) < 0) {
+		fprintf(stderr, "seting the network namespace failed: %s\n",
+			strerror(errno));
+		return -1;
+	}
+
+	if (unshare(CLONE_NEWNS) < 0) {
+		fprintf(stderr, "unshare failed: %s\n", strerror(errno));
+		return -1;
+	}
+	/* Mount a version of /sys that describes the network namespace */
+	if (umount2("/sys", MNT_DETACH) < 0) {
+		fprintf(stderr, "umount of /sys failed: %s\n", strerror(errno));
+		return -1;
+	}
+	if (mount(name, "/sys", "sysfs", 0, NULL) < 0) {
+		fprintf(stderr, "mount of /sys failed: %s\n",strerror(errno));
+		return -1;
+	}
+
+	/* Setup bind mounts for config files in /etc */
+	bind_etc(name);
+
+	if (execvp(cmd, argv + 1)  < 0)
+		fprintf(stderr, "exec of %s failed: %s\n",
+			cmd, strerror(errno));
+	exit(-1);
+}
+
+static int netns_delete(int argc, char **argv)
+{
+	const char *name;
+	char netns_path[MAXPATHLEN];
+
+	if (argc < 1) {
+		fprintf(stderr, "No netns name specified\n");
+		return -1;
+	}
+
+	name = argv[0];
+	snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, name);
+	umount2(netns_path, MNT_DETACH);
+	if (unlink(netns_path) < 0) {
+		fprintf(stderr, "Cannot remove %s: %s\n",
+			netns_path, strerror(errno));
+		return -1;
+	}
+	return 0;
+}
+
+static int netns_add(int argc, char **argv)
+{
+	/* This function creates a new network namespace and
+	 * a new mount namespace and bind them into a well known
+	 * location in the filesystem based on the name provided.
+	 *
+	 * The mount namespace is created so that any necessary
+	 * userspace tweaks like remounting /sys, or bind mounting
+	 * a new /etc/resolv.conf can be shared between uers.
+	 */
+	char netns_path[MAXPATHLEN];
+	const char *name;
+
+	if (argc < 1) {
+		fprintf(stderr, "No netns name specified\n");
+		return -1;
+	}
+	name = argv[0];
+
+	snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, name);
+
+	/* Create the base netns directory if it doesn't exist */
+	mkdir(NETNS_RUN_DIR, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
+
+	/* Create the filesystem state */
+	if (touch(netns_path, 0) < 0) {
+		fprintf(stderr, "Could not create %s: %s\n",
+			netns_path, strerror(errno));
+		goto out_delete;
+	}
+	if (unshare(CLONE_NEWNET) < 0) {
+		fprintf(stderr, "Failed to create a new network namespace: %s\n",
+			strerror(errno));
+		goto out_delete;
+	}
+
+	/* Bind the netns last so I can watch for it */
+	if (mount("/proc/self/ns/net", netns_path, "none", MS_BIND, NULL) < 0) {
+		fprintf(stderr, "Bind /proc/self/ns/net -> %s failed: %s\n",
+			netns_path, strerror(errno));
+		goto out_delete;
+	}
+	return 0;
+out_delete:
+	netns_delete(argc, argv);
+	exit(-1);
+	return -1;
+}
+
+
+static int netns_monitor(int argc, char **argv)
+{
+	char buf[4096];
+	struct inotify_event *event;
+	int fd;
+	fd = inotify_init();
+	if (fd < 0) {
+		fprintf(stderr, "inotify_init failed: %s\n",
+			strerror(errno));
+		return -1;
+	}
+	if (inotify_add_watch(fd, NETNS_RUN_DIR, IN_CREATE | IN_DELETE) < 0) {
+		fprintf(stderr, "inotify_add_watch failed: %s\n",
+			strerror(errno));
+		return -1;
+	}
+	for(;;) {
+		ssize_t len = read(fd, buf, sizeof(buf));
+		if (len < 0) {
+			fprintf(stderr, "read failed: %s\n",
+				strerror(errno));
+			return -1;
+		}
+		for (event = (struct inotify_event *)buf;
+		     (char *)event < &buf[len];
+		     event = (struct inotify_event *)((char *)event + sizeof(*event) + event->len)) {
+			if (event->mask & IN_CREATE)
+				printf("add %s\n", event->name);
+			if (event->mask & IN_DELETE)
+				printf("delete %s\n", event->name);
+		}
+	}
+	return 0;
+}
+
+int do_netns(int argc, char **argv)
+{
+	if (argc < 1)
+		return netns_list(0, NULL);
+
+	if ((matches(*argv, "list") == 0) || (matches(*argv, "show") == 0) ||
+	    (matches(*argv, "lst") == 0))
+		return netns_list(argc-1, argv+1);
+
+	if (matches(*argv, "help") == 0)
+		usage();
+
+	if (matches(*argv, "add") == 0)
+		return netns_add(argc-1, argv+1);
+
+	if (matches(*argv, "delete") == 0)
+		return netns_delete(argc-1, argv+1);
+
+	if (matches(*argv, "exec") == 0)
+		return netns_exec(argc-1, argv+1);
+
+	if (matches(*argv, "monitor") == 0)
+		return netns_monitor(argc-1, argv+1);
+
+	fprintf(stderr, "Command \"%s\" is unknown, try \"ip netns help\".\n", *argv);
+	exit(-1);
+}
diff --git a/man/man8/ip.8 b/man/man8/ip.8
index c5248ef..1935dc5 100644
--- a/man/man8/ip.8
+++ b/man/man8/ip.8
@@ -85,6 +85,9 @@ ip \- show / manipulate routing, devices, policy routing and tunnels
 .B  netns
 .IR PID " |"
 .br
+.B  netns
+.IR NETNSNAME " |"
+.br
 .B alias
 .IR NAME  " |"
 .br
@@ -162,6 +165,17 @@ tentative " | " deprecated " | " dadfailed " | " temporary " ]"
 .BR "ip addrlabel" " { " list " | " flush " }"
 
 .ti -8
+.BR "ip netns" " { " list " | " monitor " } "
+
+.ti -8
+.BR "ip netns" " { " add " | " delete " } "
+.I NETNSNAME
+
+.ti -8
+.BR "ip netns exec "
+.I NETNSNAME command ...
+
+.ti -8
 .BR "ip route" " { "
 .BR list " | " flush " } "
 .I  SELECTOR
@@ -1006,6 +1020,11 @@ move the device to the network namespace associated with the process
 .IR "PID".
 
 .TP
+.BI netns " NETNSNAME"
+move the device to the network namespace associated with name
+.IR "NETNSNAME".
+
+.TP
 .BI alias " NAME"
 give the device a symbolic name for easy reference.
 
@@ -2470,6 +2489,43 @@ at any time.
 It prepends the history with the state snapshot dumped at the moment
 of starting.
 
+.SH ip netns - process network namespace management
+
+A network namespace is logically another copy of the network stack,
+with it's own routes, firewall rules, and network devices.
+
+By convention a named network namespace is an object at
+.BR "/var/run/netns/" NAME
+that can be opened.  The file descriptor resulting from opening
+.BR "/var/run/netns/" NAME 
+refers to the specified network namespace.  Holding that file
+descriptor open keeps the network namespace alive.  The file
+descriptor can be used with the
+.B setns(2)
+system call to change the network namespace associated with a task.
+
+The convention for network namespace aware applications is to look
+for global network configuration files first in
+.BR "/etc/netns/" NAME "/"
+then in
+.BR "/etc/".
+For example, if you want a different version of
+.BR /etc/resolv.conf
+for a network namespace used to isolate your vpn you would name it
+.BR /etc/netns/myvpn/resolv.conf.
+
+.B ip netns exec
+automates handling of this configuration, file convention for network
+namespace unaware applications, by creating a mount namespace and
+bind mounting all of the per network namespace configure files into
+their traditional location in /etc.
+
+.SS ip netns list - show all of the named network namespaces
+.SS ip netns monitor - report when network namespace names are created and destroyed
+.SS ip netns add NAME - create a new named network namespace
+.SS ip netns delete NAME - delete the name of a network namespace
+.SS ip netns exec NAME cmd ... - Run cmd in the named network namespace
+
 .SH ip xfrm - setting xfrm
 xfrm is an IP framework, which can transform format of the datagrams,
 .br
-- 
1.7.5.1.217.g4e3aa

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Alex Bligh]

Eric,

--On 7 May 2011 07:18:44 -0700 "Eric W. Biederman" <ebiederm@xmission.com> 
wrote:

> You are essentially describing my setns system call.

Great - thanks.

>> As a secondary issue, ever without your patch, it would be really
>> useful to be able to read from userspace the current network namespace.
>> (i.e. the pid concerned, or 1 if not unshared). I would like to
>> simply modify a routing daemon's init script so it doesn't start
>> if in the host, e.g. at the top:
>>  [ `cat /proc/.../networknamespace` eq 1 ] && exit 0
>
> You can read the processes network namespace by opening
> /proc/<pid>/ns/net.  Unfortunately comparing the network
> namespaces for identity is another matter.  You will probably
> be better off simply forcing the routing daemon to start
> in the desired network namespace in it's initscript.

It's solely a minor convenience issue. The network namespace is
unshared by the filing system namespace isn't. So there's an
/etc/init.d/bird, which I would like to remain there so I
can call it from the network namespace concerned (which
doesn't exist at boot time). But I'd also like it not to run
at boot time. So it would be useful to me if the script could
check whether it is running in the default namespace and
refuse to launch if so.

I note the /proc/ file you mention is not present in the main tree at
the moment.

> For purposes of clarity please have a look at my work in
> progress patch for iproute2.  This demonstrates how I expect
> userspace to work in a multi-network namespace world.

Will do

-- 
Alex Bligh

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[David Lamparter]

On Sat, May 07, 2011 at 07:18:44AM -0700, Eric W. Biederman wrote:
> You can read the processes network namespace by opening
> /proc/<pid>/ns/net.  Unfortunately comparing the network
> namespaces for identity is another matter.  You will probably
> be better off simply forcing the routing daemon to start
> in the desired network namespace in it's initscript.
> 
> For purposes of clarity please have a look at my work in
> progress patch for iproute2.  This demonstrates how I expect
> userspace to work in a multi-network namespace world.
> 
[...]
> Subject: [PATCH] iproute2:  Add processless netnwork namespace support.
[...]
> Configuration specific to a network namespace that
> would ordinarily be stored under /etc/ is stored under
> /etc/netns/<name>.  For example if the dns server
> configuration is different for your vpn you would
> create a file /etc/netns/myvpn/resolv.conf.
> 
> File descriptors that can be used to manipulate a
> network namespace can be created by opening
> /var/run/netns/<NAME>.
> 
> This adds the following commands to iproute.
> ip netns add NAME
> ip netns delete NAME
> ip netns monitor
> ip netns list
> ip netns exec NAME cmd ....
> ip link set DEV netns NAME

funny, this is almost exactly what my code does - though you're probably
doing it better and have more features ;)
http://git.spaceboyz.net/equinox/vrf-tools.git/
git://spaceboyz.net/equinox/vrf-tools.git

It currently forks off a daemon to keep the namespace open; attaching is
not possible yet, but opening a socket in a different namespace is.

Most of the actual management (mounting things & co.) I offloaded to
some shell scripts; I use it together with GNU screen (which makes it
very nice to grab one of the namespaces and start/stop/manage/...
things).

I also have patches for OpenVPN and pptpd floating around that make it
possible to 'cross' namespace boundaries, i.e. the VPN servers listen in
one namespace and have their devices in another.


-David

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[David Lamparter]

On Sat, May 07, 2011 at 07:18:44AM -0700, Eric W. Biederman wrote:
> You can read the processes network namespace by opening
> /proc/<pid>/ns/net.  Unfortunately comparing the network
> namespaces for identity is another matter.  You will probably
> be better off simply forcing the routing daemon to start
> in the desired network namespace in it's initscript.
> 
> For purposes of clarity please have a look at my work in
> progress patch for iproute2.  This demonstrates how I expect
> userspace to work in a multi-network namespace world.
> 
[...]
> Subject: [PATCH] iproute2:  Add processless netnwork namespace support.
[...]
> Configuration specific to a network namespace that
> would ordinarily be stored under /etc/ is stored under
> /etc/netns/<name>.  For example if the dns server
> configuration is different for your vpn you would
> create a file /etc/netns/myvpn/resolv.conf.
> 
> File descriptors that can be used to manipulate a
> network namespace can be created by opening
> /var/run/netns/<NAME>.
> 
> This adds the following commands to iproute.
> ip netns add NAME
> ip netns delete NAME
> ip netns monitor
> ip netns list
> ip netns exec NAME cmd ....
> ip link set DEV netns NAME

funny, this is almost exactly what my code does - though you're probably
doing it better and have more features ;)
http://git.spaceboyz.net/equinox/vrf-tools.git/
git://spaceboyz.net/equinox/vrf-tools.git

It currently forks off a daemon to keep the namespace open; attaching is
not possible yet, but opening a socket in a different namespace is.

Most of the actual management (mounting things & co.) I offloaded to
some shell scripts; I use it together with GNU screen (which makes it
very nice to grab one of the namespaces and start/stop/manage/...
things).

I also have patches for OpenVPN and pptpd floating around that make it
possible to 'cross' namespace boundaries, i.e. the VPN servers listen in
one namespace and have their devices in another.


-David

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Eric W. Biederman]

David Lamparter <equinox@diac24.net> writes:

> On Sat, May 07, 2011 at 07:18:44AM -0700, Eric W. Biederman wrote:
>> You can read the processes network namespace by opening
>> /proc/<pid>/ns/net.  Unfortunately comparing the network
>> namespaces for identity is another matter.  You will probably
>> be better off simply forcing the routing daemon to start
>> in the desired network namespace in it's initscript.
>> 
>> For purposes of clarity please have a look at my work in
>> progress patch for iproute2.  This demonstrates how I expect
>> userspace to work in a multi-network namespace world.
>> 
> [...]
>> Subject: [PATCH] iproute2:  Add processless netnwork namespace support.
> [...]
>> Configuration specific to a network namespace that
>> would ordinarily be stored under /etc/ is stored under
>> /etc/netns/<name>.  For example if the dns server
>> configuration is different for your vpn you would
>> create a file /etc/netns/myvpn/resolv.conf.
>> 
>> File descriptors that can be used to manipulate a
>> network namespace can be created by opening
>> /var/run/netns/<NAME>.
>> 
>> This adds the following commands to iproute.
>> ip netns add NAME
>> ip netns delete NAME
>> ip netns monitor
>> ip netns list
>> ip netns exec NAME cmd ....
>> ip link set DEV netns NAME
>
> funny, this is almost exactly what my code does - though you're probably
> doing it better and have more features ;)

Well if it has more features it is only because I have managed to keep
everything simple enough that adding features was easy.  I ignored all
of the hard bits.

> http://git.spaceboyz.net/equinox/vrf-tools.git/
> git://spaceboyz.net/equinox/vrf-tools.git
>
> It currently forks off a daemon to keep the namespace open; attaching is
> not possible yet, but opening a socket in a different namespace is.

I went the round of keeping a daemon open, saw how much code that
takes and how fragile that can be in the corner cases and decided to
patch the kernel to make the interfaces better.

> Most of the actual management (mounting things & co.) I offloaded to
> some shell scripts; I use it together with GNU screen (which makes it
> very nice to grab one of the namespaces and start/stop/manage/...
> things).

That does sound like a nice way of doing the management.

> I also have patches for OpenVPN and pptpd floating around that make it
> possible to 'cross' namespace boundaries, i.e. the VPN servers listen in
> one namespace and have their devices in another.

For openvpn I have managed to get away with simply using an up script. 
Mostly the script is:

ip netns add $NSNAME || true
ip netns exec $NSNAME ip link set lo up
ip link set $dev netns $NSNAME
ip netns exec $NSNAME ip link set $dev up
ip netns exec $NSNAME ifconfig $dev $ifconfig_local netmask $ifconfig_netmask broadcast $ifconfig_broadcast

With a few extra bits for dns options and routes.  If I had an openvpn
built with the iproute option I expect I could get away by just wrapping
iproute.  Not that I would mind a patched openvpn.

Personally I think using a vpn in a network namespace seems like a
killer feature.

Eric

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[David Lamparter]

On Tue, May 17, 2011 at 07:33:18AM -0700, Eric W. Biederman wrote:
> I went the round of keeping a daemon open, saw how much code that
> takes and how fragile that can be in the corner cases and decided to
> patch the kernel to make the interfaces better.

Yes, it is more fragile. I'm currently using it without setns-patched
kernels though, so it's all I have.

(More or less related, I was able to cause a kernel oops on doing a
"find /proc" on setns-patched kernels after bind-mounting /proc; I did
not report it because I'm running grsecurity-patched kernels which tend
to mess with /proc quite a bit... I'll try to reproduce it with your
current patches on an otherwise vanilla kernel.)

> > I also have patches for OpenVPN and pptpd floating around that make it
> > possible to 'cross' namespace boundaries, i.e. the VPN servers listen in
> > one namespace and have their devices in another.
> 
> For openvpn I have managed to get away with simply using an up script. 
> Mostly the script is:
> 
> ip netns add $NSNAME || true
> ip netns exec $NSNAME ip link set lo up
> ip link set $dev netns $NSNAME

Historic annotation: This line used to kernel panic around a year and a
half back - nowadays tap devices do get the netns move right...

> ip netns exec $NSNAME ip link set $dev up
> ip netns exec $NSNAME ifconfig $dev $ifconfig_local netmask $ifconfig_netmask broadcast $ifconfig_broadcast
> 
> With a few extra bits for dns options and routes.  If I had an openvpn
> built with the iproute option I expect I could get away by just wrapping
> iproute.  Not that I would mind a patched openvpn.

I didn't even try to make amends for DNS, I just put 127.0.0.1 and have
caches in each of the namespaces. Wrapping iproute2 would work; one of
the advantages of patching OpenVPN is that the OpenVPN daemon is in the
same namespace as the tap devices and can do all the configuration as
usual.

For pptp, er, well, reading up on how ppp devices behave if you splice
them across namespace boundaries would've taken more time than patching
up the UDP/GRE sockets.

> Personally I think using a vpn in a network namespace seems like a
> killer feature.

Yes, it very much is - it provides very nice and clean solutions to
problems that up to now were usually hacked around with policy routing &
co.


-David

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Renato Westphal]

Eric,

I'm happy to see that these patches have been integrated into the
mainstream kernel, as you know I'm using them for a while and they are
a essential part of my MPLS/BGP VPN solution, which I will release to
the open-source community anytime soon.

It would also be good if the MPLS core get integrated into mainstream,
but that's another discussion ;)

-- 
Renato Westphal

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[David Miller]

The networking bits look OK to me:

Acked-by: David S. Miller <davem@davemloft.net>

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Eric W. Biederman]

David Miller <davem@davemloft.net> writes:

> The networking bits look OK to me:
>
> Acked-by: David S. Miller <davem@davemloft.net>

Are you merging sendmmsg through the netdev tree?

The conflicts on syscall syscall numbers are an unfortunate pain.

Eric

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[David Miller]

From: ebiederm@xmission.com (Eric W. Biederman)
Date: Mon, 09 May 2011 12:59:55 -0700

> David Miller <davem@davemloft.net> writes:
> 
>> The networking bits look OK to me:
>>
>> Acked-by: David S. Miller <davem@davemloft.net>
> 
> Are you merging sendmmsg through the netdev tree?

Yes.

> The conflicts on syscall syscall numbers are an unfortunate pain.

The way we've solved this before is the tree that cares pulls in
the net-next-2.6 tree to resolve the conflict.

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Eric W. Biederman]

David Miller <davem@davemloft.net> writes:

> From: ebiederm@xmission.com (Eric W. Biederman)
> Date: Mon, 09 May 2011 12:59:55 -0700
>
>> David Miller <davem@davemloft.net> writes:
>> 
>>> The networking bits look OK to me:
>>>
>>> Acked-by: David S. Miller <davem@davemloft.net>
>> 
>> Are you merging sendmmsg through the netdev tree?
>
> Yes.
>
>> The conflicts on syscall syscall numbers are an unfortunate pain.
>
> The way we've solved this before is the tree that cares pulls in
> the net-next-2.6 tree to resolve the conflict.

If that is the precedent that then that makes sense.  You are good
at not rewinding net-next so I don't expect there will be a problem
there.

Do you know if there are any plans to support sendmmsg on parisc for
2.6.40?  That could get sticky as the parisc tree has a bunch of syscall
catchup support they are doing now.

Eric

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[David Miller]

From: ebiederm@xmission.com (Eric W. Biederman)
Date: Mon, 09 May 2011 13:54:37 -0700

> Do you know if there are any plans to support sendmmsg on parisc for
> 2.6.40?  That could get sticky as the parisc tree has a bunch of syscall
> catchup support they are doing now.

If you would like, you could send me a patch for net-next-2.6 that adds
the sendmmsg syscall entries and hooks for all the platforms not taken
care of right now.

RE: [PATCH 0/7] Network namespace manipulation with file descriptors

[Luck, Tony]

>> The conflicts on syscall syscall numbers are an unfortunate pain.
>
> The way we've solved this before is the tree that cares pulls in
> the net-next-2.6 tree to resolve the conflict.

Actually it seems more common that new syscalls are only added to
x86 (plus one or more other architectures that the author cares
about). Then arch maintainers throw in a "wire up new syscalls"
patch during the merge window when they see these new bits show up.

-Tony

Oh - ia64 wiring looks good.

Acked-by: Tony Luck <tony.luck@intel.com>

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Eric W. Biederman]

ebiederm@xmission.com (Eric W. Biederman) writes:


> These changes are also available at:
> git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/linux-2.6-nsfd.git

I have noted the acknowledgments, fixed the bugs and resolved the syscall
conflicts.

Eric

Re: [PATCH 0/7] Network namespace manipulation with file descriptors

[Eric W. Biederman]

ebiederm@xmission.com (Eric W. Biederman) writes:


> These changes are also available at:
> git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/linux-2.6-nsfd.git

I have noted the acknowledgments, fixed the bugs and resolved the syscall
conflicts.

Eric

Identifying network namespaces (was: Network namespace manipulation with file descriptors)

[David Lamparter]

On Fri, May 06, 2011 at 07:23:29PM -0700, Eric W. Biederman wrote:
> Today there are something things you can use namespaces to implement but
> the userspace code is unnecessarily complex and fragile because of
> limitations of the kernel interfaces.

(I hope I'm not duplicating stuff here, maybe this is already taken care
of...)

There still is the unresolved issue of identifying and/or equality
testing network namespaces. The problems I see are the following:

Problems
========

-   there is no simple list of the existing namespaces
 
  most importantly, network namespaces can be abused very sneakily to
  provide trojans or other malicious software with a covert
  communication channel.

  Just create a macvlan device on the local ethernet, shift it into a
  new namespace, grab an IP - and the admin of the host will be left
  dumbfounded with his plain old netstat or ss as to where those weird
  packets are coming from.

  (Granted, this needs root privileges and you can still see everything
  in /proc/<pid>/net/{tcp,udp,...})

-   processes cannot easily be cross referenced with each other

  in the case of user space stuff running astray - like management
  software crashing, routing daemons screwing up, etc. - it becomes
  fairly difficult to shut down a network namespace (or even reaquire
  physical devices that have been reassigned)

-   namespaces cannot adequately be identified to the user

  for debugging, some kernel messages become useless. most prominently,
  "unregister_netdevice: waiting for lo to become free. Usage count = 123"
  could certainly use some clarification, *which* lo is meant...

So, considering this set of premises (feedback welcome) I looked for
some suitable means of identification. I discarded going for any process
identifiers since Eric's patches allow for network namespaces without
any process holding a reference, using bind mounts instead.

Solution?
=========

I do think I found another identifier suitable for both exporting a full 
list and providing "getid" functionality: the "lo" interface index.
I am not fully sure on the rules here, but to my understanding the lo
interface index should be constant for the lifetime of a network
namespace, and furthermore the interface index namespace is global to
the kernel.

This can already be used right now:
- you can identify the init namespace since its lo index is 1
- you can use netlink (or SIOCGIFINDEX, ew.) to get your own ID
- as soon as you have the means to attach to a namespace, you
  automatically also have the means to get its ID

What might need to be added:
1) a list of lo indices
2) a way to get a hold of the namespace using its lo index
3) maybe dmesg output on creation/destruction for the abuse case above
4) possibly a file in /proc/<pid>/net that just contains the lo index,
  for ease of use

3) and 4) should be trivial; 1) and 2) could be solved by having a
directory in /proc (?) that has all the network namespace "files" with
their lo indices as names.


So, ... Opinions?


-David

Re: Identifying network namespaces (was: Network namespace manipulation with file descriptors)

[Alexey Dobriyan]

On Wed, May 18, 2011 at 3:43 PM, David Lamparter <equinox@diac24.net> wrote:
> -   processes cannot easily be cross referenced with each other
>
>  in the case of user space stuff running astray - like management
>  software crashing, routing daemons screwing up, etc. - it becomes
>  fairly difficult to shut down a network namespace (or even reaquire
>  physical devices that have been reassigned)

It shutdowns itself when last process using netns disappeares,
so if you kill your routing daemons you should be fine.
Physical netdevices are moved to init_net.

> -   namespaces cannot adequately be identified to the user
>
>  for debugging, some kernel messages become useless. most prominently,
>  "unregister_netdevice: waiting for lo to become free. Usage count = 123"
>  could certainly use some clarification, *which* lo is meant...

There is no "netns %p" or something, because right now the only unique
netns identifier is kernel pointer (which better not be exposed to userspace).
Printing such thing would be quite useless since it's not printed
at netns creation.

> So, considering this set of premises (feedback welcome) I looked for
> some suitable means of identification. I discarded going for any process
> identifiers since Eric's patches allow for network namespaces without
> any process holding a reference, using bind mounts instead.

If anything it should be netns->id, /proc/*/netns outputting id
where id is not derived from kernel pointer.

> Solution?
> =========

What a hack! :-)

Re: Identifying network namespaces (was: Network namespace manipulation with file descriptors)

[David Lamparter]

On Wed, May 18, 2011 at 04:03:03PM +0300, Alexey Dobriyan wrote:
> On Wed, May 18, 2011 at 3:43 PM, David Lamparter <equinox@diac24.net> wrote:
> > -   processes cannot easily be cross referenced with each other
> >
> >  in the case of user space stuff running astray - like management
> >  software crashing, routing daemons screwing up, etc. - it becomes
> >  fairly difficult to shut down a network namespace (or even reaquire
> >  physical devices that have been reassigned)
> 
> It shutdowns itself when last process using netns disappeares,
> so if you kill your routing daemons you should be fine.
> Physical netdevices are moved to init_net.

Now assume I'm running pptpd, which forks a new pppd for each
connection. Even if I kill pptpd, the pppd keeps running... now how do I
find the pppds that belong to that one namespace that I'm trying to
get rid of?

> > -   namespaces cannot adequately be identified to the user
> >
> >  for debugging, some kernel messages become useless. most prominently,
> >  "unregister_netdevice: waiting for lo to become free. Usage count = 123"
> >  could certainly use some clarification, *which* lo is meant...
> 
> There is no "netns %p" or something, because right now the only unique
> netns identifier is kernel pointer (which better not be exposed to userspace).
> Printing such thing would be quite useless since it's not printed
> at netns creation.

I agree printing the kernel pointer is point-less.

> > So, considering this set of premises (feedback welcome) I looked for
> > some suitable means of identification. I discarded going for any process
> > identifiers since Eric's patches allow for network namespaces without
> > any process holding a reference, using bind mounts instead.
> 
> If anything it should be netns->id, /proc/*/netns outputting id
> where id is not derived from kernel pointer.
> 
> > Solution?
> > [ using lo interface index ]
> 
> What a hack! :-)

Well, you could create another counter and count it up on namespace
creation. But the interface index is readily available to userspace as
is, and it uniquely identifies the network namespace.

(Stupidest thing you can do to break this is renaming the loopback
device; but even if you do that userspace can still look at the LOOPBACK
flag.)


-David

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Re: Identifying network namespaces (was: Network namespace manipulation with file descriptors)

[David Lamparter]

On Wed, May 18, 2011 at 04:03:03PM +0300, Alexey Dobriyan wrote:
> On Wed, May 18, 2011 at 3:43 PM, David Lamparter <equinox@diac24.net> wrote:
> > -   processes cannot easily be cross referenced with each other
> >
> >  in the case of user space stuff running astray - like management
> >  software crashing, routing daemons screwing up, etc. - it becomes
> >  fairly difficult to shut down a network namespace (or even reaquire
> >  physical devices that have been reassigned)
> 
> It shutdowns itself when last process using netns disappeares,
> so if you kill your routing daemons you should be fine.
> Physical netdevices are moved to init_net.

Now assume I'm running pptpd, which forks a new pppd for each
connection. Even if I kill pptpd, the pppd keeps running... now how do I
find the pppds that belong to that one namespace that I'm trying to
get rid of?

> > -   namespaces cannot adequately be identified to the user
> >
> >  for debugging, some kernel messages become useless. most prominently,
> >  "unregister_netdevice: waiting for lo to become free. Usage count = 123"
> >  could certainly use some clarification, *which* lo is meant...
> 
> There is no "netns %p" or something, because right now the only unique
> netns identifier is kernel pointer (which better not be exposed to userspace).
> Printing such thing would be quite useless since it's not printed
> at netns creation.

I agree printing the kernel pointer is point-less.

> > So, considering this set of premises (feedback welcome) I looked for
> > some suitable means of identification. I discarded going for any process
> > identifiers since Eric's patches allow for network namespaces without
> > any process holding a reference, using bind mounts instead.
> 
> If anything it should be netns->id, /proc/*/netns outputting id
> where id is not derived from kernel pointer.
> 
> > Solution?
> > [ using lo interface index ]
> 
> What a hack! :-)

Well, you could create another counter and count it up on namespace
creation. But the interface index is readily available to userspace as
is, and it uniquely identifies the network namespace.

(Stupidest thing you can do to break this is renaming the loopback
device; but even if you do that userspace can still look at the LOOPBACK
flag.)


-David

Re: Identifying network namespaces (was: Network namespace manipulation with file descriptors)

[Alexey Dobriyan]

On Wed, May 18, 2011 at 4:33 PM, David Lamparter <equinox@diac24.net> wrote:
> On Wed, May 18, 2011 at 04:03:03PM +0300, Alexey Dobriyan wrote:
>> On Wed, May 18, 2011 at 3:43 PM, David Lamparter <equinox@diac24.net> wrote:
>> > -   processes cannot easily be cross referenced with each other
>> >
>> >  in the case of user space stuff running astray - like management
>> >  software crashing, routing daemons screwing up, etc. - it becomes
>> >  fairly difficult to shut down a network namespace (or even reaquire
>> >  physical devices that have been reassigned)
>>
>> It shutdowns itself when last process using netns disappeares,
>> so if you kill your routing daemons you should be fine.
>> Physical netdevices are moved to init_net.
>
> Now assume I'm running pptpd, which forks a new pppd for each
> connection. Even if I kill pptpd, the pppd keeps running... now how do I
> find the pppds that belong to that one namespace that I'm trying to
> get rid of?

That's a valid question.

>> > So, considering this set of premises (feedback welcome) I looked for
>> > some suitable means of identification. I discarded going for any process
>> > identifiers since Eric's patches allow for network namespaces without
>> > any process holding a reference, using bind mounts instead.
>>
>> If anything it should be netns->id, /proc/*/netns outputting id
>> where id is not derived from kernel pointer.

Actually it should be symlink
/proc/net/netns -> 0         # for init_net
/proc/net/netns -> u32 (> 0)   # for the rest
to extract information by 1 syscall, not 3
where netns id is totally random, so userspace won't make assumptions.