From: David Howells <dhowells@redhat.com>
To: keyrings@vger.kernel.org, trond.myklebust@hammerspace.com,
sfrench@samba.org
Cc: linux-security-module@vger.kernel.org, linux-nfs@vger.kernel.org,
linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
rgb@redhat.com, dhowells@redhat.com,
linux-kernel@vger.kernel.org
Subject: [RFC PATCH 03/27] containers: Provide /proc/containers
Date: Fri, 15 Feb 2019 16:07:41 +0000 [thread overview]
Message-ID: <155024686175.21651.6141317051029384847.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <155024683432.21651.14153938339749694146.stgit@warthog.procyon.org.uk>
Provide /proc/containers to view the current container and all the
containers created within it:
# ./foo-container
NAME USE FL OWNER GROUP
<current> 141 01 0 0
foo-test 1 04 0 0
I'm not sure whether this is really desirable, though.
Signed-off-by: David Howells <dhowells@redhat.com>
---
kernel/container.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 110 insertions(+)
diff --git a/kernel/container.c b/kernel/container.c
index ca4012632cfa..1d2cb1c1e9b1 100644
--- a/kernel/container.c
+++ b/kernel/container.c
@@ -20,6 +20,7 @@
#include <linux/syscalls.h>
#include <linux/printk.h>
#include <linux/security.h>
+#include <linux/proc_fs.h>
#include "namespaces.h"
struct container init_container = {
@@ -69,6 +70,108 @@ void put_container(struct container *c)
}
}
+static void *container_proc_start(struct seq_file *m, loff_t *_pos)
+{
+ struct container *c = m->private;
+ struct list_head *p;
+ loff_t pos = *_pos;
+
+ spin_lock(&c->lock);
+
+ if (pos <= 1) {
+ *_pos = 1;
+ return (void *)1UL; /* Banner on first line */
+ }
+
+ if (pos == 2)
+ return m->private; /* Current container on second line */
+
+ /* Subordinate containers thereafter */
+ p = c->children.next;
+ pos--;
+ for (pos--; pos > 0 && p != &c->children; pos--) {
+ p = p->next;
+ }
+
+ if (p == &c->children)
+ return NULL;
+ return container_of(p, struct container, child_link);
+}
+
+static void *container_proc_next(struct seq_file *m, void *v, loff_t *_pos)
+{
+ struct container *c = m->private, *vc = v;
+ struct list_head *p;
+ loff_t pos = *_pos;
+
+ pos++;
+ *_pos = pos;
+ if (pos == 2)
+ return c; /* Current container on second line */
+
+ if (pos == 3)
+ p = &c->children;
+ else
+ p = &vc->child_link;
+ p = p->next;
+ if (p == &c->children)
+ return NULL;
+ return container_of(p, struct container, child_link);
+}
+
+static void container_proc_stop(struct seq_file *m, void *v)
+{
+ struct container *c = m->private;
+
+ spin_unlock(&c->lock);
+}
+
+static int container_proc_show(struct seq_file *m, void *v)
+{
+ struct user_namespace *uns = current_user_ns();
+ struct container *c = v;
+ const char *name;
+
+ if (v == (void *)1UL) {
+ seq_puts(m, "NAME ID USE FL OWNER GROUP\n");
+ return 0;
+ }
+
+ name = (c == m->private) ? "<current>" : c->name;
+ seq_printf(m, "%-24s %12llu %3u %02lx %5d %5d\n",
+ name, c->id, refcount_read(&c->usage), c->flags,
+ from_kuid_munged(uns, c->cred->uid),
+ from_kgid_munged(uns, c->cred->gid));
+
+ return 0;
+}
+
+static const struct seq_operations container_proc_ops = {
+ .start = container_proc_start,
+ .next = container_proc_next,
+ .stop = container_proc_stop,
+ .show = container_proc_show,
+};
+
+static int container_proc_open(struct inode *inode, struct file *file)
+{
+ struct seq_file *m;
+ int ret = seq_open(file, &container_proc_ops);
+
+ if (ret == 0) {
+ m = file->private_data;
+ m->private = current->container;
+ }
+ return ret;
+}
+
+static const struct file_operations container_proc_fops = {
+ .open = container_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
/*
* Allow the user to poll for the container dying.
*/
@@ -345,4 +448,11 @@ SYSCALL_DEFINE5(container_create,
return fd;
}
+static int __init init_container_fs(void)
+{
+ proc_create("containers", 0, NULL, &container_proc_fops);
+ return 0;
+}
+fs_initcall(init_container_fs);
+
#endif /* CONFIG_CONTAINERS */
next prev parent reply other threads:[~2019-02-15 16:07 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-15 16:07 [RFC PATCH 00/27] Containers and using authenticated filesystems David Howells
2019-02-15 16:07 ` [RFC PATCH 01/27] containers: Rename linux/container.h to linux/container_dev.h David Howells
2019-02-15 16:07 ` [RFC PATCH 02/27] containers: Implement containers as kernel objects David Howells
2019-02-17 18:57 ` Trond Myklebust
2019-02-17 19:39 ` James Bottomley
2019-02-19 16:56 ` Eric W. Biederman
2019-02-19 23:03 ` David Howells
2019-02-20 14:23 ` Trond Myklebust
2019-02-19 23:06 ` David Howells
2019-02-20 2:20 ` James Bottomley
2019-02-20 3:04 ` Ian Kent
2019-02-20 3:46 ` James Bottomley
2019-02-20 4:42 ` Ian Kent
2019-02-20 6:57 ` Paul Moore
2019-02-19 23:13 ` David Howells
2019-02-19 23:55 ` Tycho Andersen
2019-02-20 2:46 ` Ian Kent
2019-02-20 13:26 ` Christian Brauner
2019-02-21 10:39 ` Ian Kent
2019-02-15 16:07 ` David Howells [this message]
2019-02-15 16:07 ` [RFC PATCH 04/27] containers: Allow a process to be forked into a container David Howells
2019-02-15 17:39 ` Stephen Smalley
2019-02-19 16:39 ` Eric W. Biederman
2019-02-19 23:16 ` David Howells
2019-02-15 16:07 ` [RFC PATCH 05/27] containers: Open a socket inside " David Howells
2019-02-19 16:41 ` Eric W. Biederman
2019-02-15 16:08 ` [RFC PATCH 06/27] containers, vfs: Allow syscall dirfd arguments to take a container fd David Howells
2019-02-19 16:45 ` Eric W. Biederman
2019-02-19 23:24 ` David Howells
2019-02-15 16:08 ` [RFC PATCH 07/27] containers: Make fsopen() able to create a superblock in a container David Howells
2019-02-15 16:08 ` [RFC PATCH 08/27] containers, vfs: Honour CONTAINER_NEW_EMPTY_FS_NS David Howells
2019-02-17 0:11 ` Al Viro
2019-02-15 16:08 ` [RFC PATCH 09/27] vfs: Allow mounting to other namespaces David Howells
2019-02-17 0:14 ` Al Viro
2019-02-15 16:08 ` [RFC PATCH 10/27] containers: Provide fs_context op for container setting David Howells
2019-02-15 16:09 ` [RFC PATCH 11/27] containers: Sample program for driving container objects David Howells
2019-02-15 16:09 ` [RFC PATCH 12/27] containers: Allow a daemon to intercept request_key upcalls in a container David Howells
2019-02-15 16:09 ` [RFC PATCH 13/27] keys: Provide a keyctl to query a request_key authentication key David Howells
2019-02-15 16:09 ` [RFC PATCH 14/27] keys: Break bits out of key_unlink() David Howells
2019-02-15 16:09 ` [RFC PATCH 15/27] keys: Make __key_link_begin() handle lockdep nesting David Howells
2019-02-15 16:09 ` [RFC PATCH 16/27] keys: Grant Link permission to possessers of request_key auth keys David Howells
2019-02-15 16:10 ` [RFC PATCH 17/27] keys: Add a keyctl to move a key between keyrings David Howells
2019-02-15 16:10 ` [RFC PATCH 18/27] keys: Find the least-recently used unseen key in a keyring David Howells
2019-02-15 16:10 ` [RFC PATCH 19/27] containers: Sample: request_key upcall handling David Howells
2019-02-15 16:10 ` [RFC PATCH 20/27] container, keys: Add a container keyring David Howells
2019-02-15 21:46 ` Eric Biggers
2019-02-15 16:11 ` [RFC PATCH 21/27] keys: Fix request_key() lack of Link perm check on found key David Howells
2019-02-15 16:11 ` [RFC PATCH 22/27] KEYS: Replace uid/gid/perm permissions checking with an ACL David Howells
2019-02-15 17:32 ` Stephen Smalley
2019-02-15 17:39 ` David Howells
2019-02-15 16:11 ` [RFC PATCH 23/27] KEYS: Provide KEYCTL_GRANT_PERMISSION David Howells
2019-02-15 16:11 ` [RFC PATCH 24/27] keys: Allow a container to be specified as a subject in a key's ACL David Howells
2019-02-15 16:11 ` [RFC PATCH 25/27] keys: Provide a way to ask for the container keyring David Howells
2019-02-15 16:12 ` [RFC PATCH 26/27] keys: Allow containers to be included in key ACLs by name David Howells
2019-02-15 16:12 ` [RFC PATCH 27/27] containers: Sample to grant access to a key in a container David Howells
2019-02-15 22:36 ` [RFC PATCH 00/27] Containers and using authenticated filesystems James Morris
2019-02-19 16:35 ` Eric W. Biederman
2019-02-20 14:18 ` Christian Brauner
2019-02-19 23:42 ` David Howells
2019-02-20 7:00 ` Paul Moore
2019-02-20 18:54 ` Steve French
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