* [PATCH v16 1/5] fs/nsfs.c: added ns_match
2019-12-18 17:38 [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task Carlos Neira
@ 2019-12-18 17:38 ` Carlos Neira
2019-12-19 18:45 ` Yonghong Song
2019-12-18 17:38 ` [PATCH v16 2/5] bpf: added new helper bpf_get_ns_current_pid_tgid Carlos Neira
` (4 subsequent siblings)
5 siblings, 1 reply; 13+ messages in thread
From: Carlos Neira @ 2019-12-18 17:38 UTC (permalink / raw)
To: netdev; +Cc: yhs, ebiederm, brouer, bpf, cneirabustos
ns_match returns true if the namespace inode and dev_t matches the ones
provided by the caller.
Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
---
fs/nsfs.c | 14 ++++++++++++++
include/linux/proc_ns.h | 2 ++
2 files changed, 16 insertions(+)
diff --git a/fs/nsfs.c b/fs/nsfs.c
index a0431642c6b5..ef59cf347285 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -245,6 +245,20 @@ struct file *proc_ns_fget(int fd)
return ERR_PTR(-EINVAL);
}
+/**
+ * ns_match() - Returns true if current namespace matches dev/ino provided.
+ * @ns_common: current ns
+ * @dev: dev_t from nsfs that will be matched against current nsfs
+ * @ino: ino_t from nsfs that will be matched against current nsfs
+ *
+ * Return: true if dev and ino matches the current nsfs.
+ */
+bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino)
+{
+ return (ns->inum == ino) && (nsfs_mnt->mnt_sb->s_dev == dev);
+}
+
+
static int nsfs_show_path(struct seq_file *seq, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
index d31cb6215905..1da9f33489f3 100644
--- a/include/linux/proc_ns.h
+++ b/include/linux/proc_ns.h
@@ -82,6 +82,8 @@ typedef struct ns_common *ns_get_path_helper_t(void *);
extern void *ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb,
void *private_data);
+extern bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino);
+
extern int ns_get_name(char *buf, size_t size, struct task_struct *task,
const struct proc_ns_operations *ns_ops);
extern void nsfs_init(void);
--
2.20.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH v16 1/5] fs/nsfs.c: added ns_match
2019-12-18 17:38 ` [PATCH v16 1/5] fs/nsfs.c: added ns_match Carlos Neira
@ 2019-12-19 18:45 ` Yonghong Song
0 siblings, 0 replies; 13+ messages in thread
From: Yonghong Song @ 2019-12-19 18:45 UTC (permalink / raw)
To: ebiederm; +Cc: Carlos Neira, netdev, brouer, bpf
On 12/18/19 9:38 AM, Carlos Neira wrote:
> ns_match returns true if the namespace inode and dev_t matches the ones
> provided by the caller.
>
> Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
> ---
> fs/nsfs.c | 14 ++++++++++++++
> include/linux/proc_ns.h | 2 ++
> 2 files changed, 16 insertions(+)
>
> diff --git a/fs/nsfs.c b/fs/nsfs.c
> index a0431642c6b5..ef59cf347285 100644
> --- a/fs/nsfs.c
> +++ b/fs/nsfs.c
> @@ -245,6 +245,20 @@ struct file *proc_ns_fget(int fd)
> return ERR_PTR(-EINVAL);
> }
>
> +/**
> + * ns_match() - Returns true if current namespace matches dev/ino provided.
> + * @ns_common: current ns
> + * @dev: dev_t from nsfs that will be matched against current nsfs
> + * @ino: ino_t from nsfs that will be matched against current nsfs
> + *
> + * Return: true if dev and ino matches the current nsfs.
> + */
> +bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino)
> +{
> + return (ns->inum == ino) && (nsfs_mnt->mnt_sb->s_dev == dev);
> +}
> +
> +
> static int nsfs_show_path(struct seq_file *seq, struct dentry *dentry)
> {
> struct inode *inode = d_inode(dentry);
> diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h
> index d31cb6215905..1da9f33489f3 100644
> --- a/include/linux/proc_ns.h
> +++ b/include/linux/proc_ns.h
> @@ -82,6 +82,8 @@ typedef struct ns_common *ns_get_path_helper_t(void *);
> extern void *ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb,
> void *private_data);
>
> +extern bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino);
> +
> extern int ns_get_name(char *buf, size_t size, struct task_struct *task,
> const struct proc_ns_operations *ns_ops);
> extern void nsfs_init(void);
Eric, the above ns_match mechanism is what we discussed and you
suggested. It would be good to get you look at it again and ack
if no further questions. Thanks!
^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH v16 2/5] bpf: added new helper bpf_get_ns_current_pid_tgid
2019-12-18 17:38 [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task Carlos Neira
2019-12-18 17:38 ` [PATCH v16 1/5] fs/nsfs.c: added ns_match Carlos Neira
@ 2019-12-18 17:38 ` Carlos Neira
2019-12-19 18:31 ` Yonghong Song
2019-12-18 17:38 ` [PATCH v16 3/5] tools: Added bpf_get_ns_current_pid_tgid helper Carlos Neira
` (3 subsequent siblings)
5 siblings, 1 reply; 13+ messages in thread
From: Carlos Neira @ 2019-12-18 17:38 UTC (permalink / raw)
To: netdev; +Cc: yhs, ebiederm, brouer, bpf, cneirabustos
New bpf helper bpf_get_ns_current_pid_tgid,
This helper will return pid and tgid from current task
which namespace matches dev_t and inode number provided,
this will allows us to instrument a process inside a container.
Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
---
include/linux/bpf.h | 1 +
include/uapi/linux/bpf.h | 19 ++++++++++++++++-
kernel/bpf/core.c | 1 +
kernel/bpf/helpers.c | 45 ++++++++++++++++++++++++++++++++++++++++
kernel/trace/bpf_trace.c | 2 ++
5 files changed, 67 insertions(+), 1 deletion(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 35903f148be5..a40b3e13cf98 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1224,6 +1224,7 @@ extern const struct bpf_func_proto bpf_get_local_storage_proto;
extern const struct bpf_func_proto bpf_strtol_proto;
extern const struct bpf_func_proto bpf_strtoul_proto;
extern const struct bpf_func_proto bpf_tcp_sock_proto;
+extern const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto;
/* Shared helpers among cBPF and eBPF. */
void bpf_user_rnd_init_once(void);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index dbbcf0b02970..75864cd91b50 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2821,6 +2821,18 @@ union bpf_attr {
* Return
* On success, the strictly positive length of the string, including
* the trailing NUL character. On error, a negative value.
+ * int bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size)
+ * Description
+ * Returns 0 on success, values for *pid* and *tgid* as seen from the current
+ * *namespace* will be returned in *nsdata*.
+ *
+ * On failure, the returned value is one of the following:
+ *
+ * **-EINVAL** if dev and inum supplied don't match dev_t and inode number
+ * with nsfs of current task, or if dev conversion to dev_t lost high bits.
+ *
+ * **-ENOENT** if pidns does not exists for the current task.
+ *
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2938,7 +2950,8 @@ union bpf_attr {
FN(probe_read_user), \
FN(probe_read_kernel), \
FN(probe_read_user_str), \
- FN(probe_read_kernel_str),
+ FN(probe_read_kernel_str), \
+ FN(get_ns_current_pid_tgid),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -3689,4 +3702,8 @@ struct bpf_sockopt {
__s32 retval;
};
+struct bpf_pidns_info {
+ __u32 pid;
+ __u32 tgid;
+};
#endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 49e32acad7d8..59b892ab2acb 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -2145,6 +2145,7 @@ const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak;
const struct bpf_func_proto bpf_get_current_comm_proto __weak;
const struct bpf_func_proto bpf_get_current_cgroup_id_proto __weak;
const struct bpf_func_proto bpf_get_local_storage_proto __weak;
+const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto __weak;
const struct bpf_func_proto * __weak bpf_get_trace_printk_proto(void)
{
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index cada974c9f4e..4aea086c20e5 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -11,6 +11,8 @@
#include <linux/uidgid.h>
#include <linux/filter.h>
#include <linux/ctype.h>
+#include <linux/pid_namespace.h>
+#include <linux/proc_ns.h>
#include "../../lib/kstrtox.h"
@@ -487,3 +489,46 @@ const struct bpf_func_proto bpf_strtoul_proto = {
.arg4_type = ARG_PTR_TO_LONG,
};
#endif
+
+BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
+ struct bpf_pidns_info *, nsdata, u32, size)
+{
+ struct task_struct *task = current;
+ struct pid_namespace *pidns;
+ int err = -EINVAL;
+
+ if (unlikely(size != sizeof(struct bpf_pidns_info)))
+ goto clear;
+
+ if (unlikely((u64)(dev_t)dev != dev))
+ goto clear;
+
+ if (unlikely(!task))
+ goto clear;
+
+ pidns = task_active_pid_ns(task);
+ if (unlikely(!pidns)) {
+ err = -ENOENT;
+ goto clear;
+ }
+
+ if (!ns_match(&pidns->ns, (dev_t)dev, ino))
+ goto clear;
+
+ nsdata->pid = task_pid_nr_ns(task, pidns);
+ nsdata->tgid = task_tgid_nr_ns(task, pidns);
+ return 0;
+clear:
+ memset((void *)nsdata, 0, (size_t) size);
+ return err;
+}
+
+const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
+ .func = bpf_get_ns_current_pid_tgid,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_ANYTHING,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_PTR_TO_UNINIT_MEM,
+ .arg4_type = ARG_CONST_SIZE,
+};
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index e5ef4ae9edb5..8c931cd1a768 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -822,6 +822,8 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
#endif
case BPF_FUNC_send_signal:
return &bpf_send_signal_proto;
+ case BPF_FUNC_get_ns_current_pid_tgid:
+ return &bpf_get_ns_current_pid_tgid_proto;
default:
return NULL;
}
--
2.20.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v16 3/5] tools: Added bpf_get_ns_current_pid_tgid helper
2019-12-18 17:38 [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task Carlos Neira
2019-12-18 17:38 ` [PATCH v16 1/5] fs/nsfs.c: added ns_match Carlos Neira
2019-12-18 17:38 ` [PATCH v16 2/5] bpf: added new helper bpf_get_ns_current_pid_tgid Carlos Neira
@ 2019-12-18 17:38 ` Carlos Neira
2019-12-19 18:31 ` Yonghong Song
2019-12-18 17:38 ` [PATCH v16 4/5] tools/testing/selftests/bpf: Add self-tests for new helper bpf_get_ns_current_pid_tgid Carlos Neira
` (2 subsequent siblings)
5 siblings, 1 reply; 13+ messages in thread
From: Carlos Neira @ 2019-12-18 17:38 UTC (permalink / raw)
To: netdev; +Cc: yhs, ebiederm, brouer, bpf, cneirabustos
sync tools/include/uapi/linux/bpf.h to include new helper.
Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
---
tools/include/uapi/linux/bpf.h | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index dbbcf0b02970..75864cd91b50 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2821,6 +2821,18 @@ union bpf_attr {
* Return
* On success, the strictly positive length of the string, including
* the trailing NUL character. On error, a negative value.
+ * int bpf_get_ns_current_pid_tgid(u64 dev, u64 ino, struct bpf_pidns_info *nsdata, u32 size)
+ * Description
+ * Returns 0 on success, values for *pid* and *tgid* as seen from the current
+ * *namespace* will be returned in *nsdata*.
+ *
+ * On failure, the returned value is one of the following:
+ *
+ * **-EINVAL** if dev and inum supplied don't match dev_t and inode number
+ * with nsfs of current task, or if dev conversion to dev_t lost high bits.
+ *
+ * **-ENOENT** if pidns does not exists for the current task.
+ *
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2938,7 +2950,8 @@ union bpf_attr {
FN(probe_read_user), \
FN(probe_read_kernel), \
FN(probe_read_user_str), \
- FN(probe_read_kernel_str),
+ FN(probe_read_kernel_str), \
+ FN(get_ns_current_pid_tgid),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -3689,4 +3702,8 @@ struct bpf_sockopt {
__s32 retval;
};
+struct bpf_pidns_info {
+ __u32 pid;
+ __u32 tgid;
+};
#endif /* _UAPI__LINUX_BPF_H__ */
--
2.20.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v16 4/5] tools/testing/selftests/bpf: Add self-tests for new helper bpf_get_ns_current_pid_tgid.
2019-12-18 17:38 [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task Carlos Neira
` (2 preceding siblings ...)
2019-12-18 17:38 ` [PATCH v16 3/5] tools: Added bpf_get_ns_current_pid_tgid helper Carlos Neira
@ 2019-12-18 17:38 ` Carlos Neira
2019-12-19 18:40 ` Yonghong Song
2019-12-18 17:38 ` [PATCH v16 5/5] bpf_helpers_doc.py: Add struct bpf_pidns_info to known types Carlos Neira
2020-01-10 1:46 ` [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task Alexei Starovoitov
5 siblings, 1 reply; 13+ messages in thread
From: Carlos Neira @ 2019-12-18 17:38 UTC (permalink / raw)
To: netdev; +Cc: yhs, ebiederm, brouer, bpf, cneirabustos
Self tests added for new helper bpf_get_ns_current_pid_tgid
Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
---
.../bpf/prog_tests/ns_current_pid_tgid.c | 88 +++++++++++++++++++
.../bpf/progs/test_ns_current_pid_tgid.c | 37 ++++++++
2 files changed, 125 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c
create mode 100644 tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c
diff --git a/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c b/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c
new file mode 100644
index 000000000000..afd4a19dda14
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/ns_current_pid_tgid.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Carlos Neira cneirabustos@gmail.com */
+#include <test_progs.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+struct bss {
+ __u64 dev;
+ __u64 ino;
+ __u64 pid_tgid;
+ __u64 user_pid_tgid;
+};
+
+void test_ns_current_pid_tgid(void)
+{
+ const char *probe_name = "raw_tracepoint/sys_enter";
+ const char *file = "test_ns_current_pid_tgid.o";
+ int err, key = 0, duration = 0;
+ struct bpf_link *link = NULL;
+ struct bpf_program *prog;
+ struct bpf_map *bss_map;
+ struct bpf_object *obj;
+ struct bss bss;
+ struct stat st;
+ __u64 id;
+
+ obj = bpf_object__open_file(file, NULL);
+ if (CHECK(IS_ERR(obj), "obj_open", "err %ld\n", PTR_ERR(obj)))
+ return;
+
+ err = bpf_object__load(obj);
+ if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno))
+ goto cleanup;
+
+ bss_map = bpf_object__find_map_by_name(obj, "test_ns_.bss");
+ if (CHECK(!bss_map, "find_bss_map", "failed\n"))
+ goto cleanup;
+
+ prog = bpf_object__find_program_by_title(obj, probe_name);
+ if (CHECK(!prog, "find_prog", "prog '%s' not found\n",
+ probe_name))
+ goto cleanup;
+
+ memset(&bss, 0, sizeof(bss));
+ pid_t tid = syscall(SYS_gettid);
+ pid_t pid = getpid();
+
+ id = (__u64) tid << 32 | pid;
+ bss.user_pid_tgid = id;
+
+ if (CHECK_FAIL(stat("/proc/self/ns/pid", &st))) {
+ perror("Failed to stat /proc/self/ns/pid");
+ goto cleanup;
+ }
+
+ bss.dev = st.st_dev;
+ bss.ino = st.st_ino;
+
+ err = bpf_map_update_elem(bpf_map__fd(bss_map), &key, &bss, 0);
+ if (CHECK(err, "setting_bss", "failed to set bss : %d\n", err))
+ goto cleanup;
+
+ link = bpf_program__attach_raw_tracepoint(prog, "sys_enter");
+ if (CHECK(IS_ERR(link), "attach_raw_tp", "err %ld\n",
+ PTR_ERR(link))) {
+ link = NULL;
+ goto cleanup;
+ }
+
+ /* trigger some syscalls */
+ usleep(1);
+
+ err = bpf_map_lookup_elem(bpf_map__fd(bss_map), &key, &bss);
+ if (CHECK(err, "set_bss", "failed to get bss : %d\n", err))
+ goto cleanup;
+
+ if (CHECK(id != bss.pid_tgid, "Compare user pid/tgid vs. bpf pid/tgid",
+ "User pid/tgid %llu BPF pid/tgid %llu\n", id, bss.pid_tgid))
+ goto cleanup;
+cleanup:
+ if (!link) {
+ bpf_link__destroy(link);
+ link = NULL;
+ }
+ bpf_object__close(obj);
+}
diff --git a/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c b/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c
new file mode 100644
index 000000000000..cdb77eb1a4fb
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_ns_current_pid_tgid.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Carlos Neira cneirabustos@gmail.com */
+
+#include <linux/bpf.h>
+#include <stdint.h>
+#include "bpf_helpers.h"
+
+static volatile struct {
+ __u64 dev;
+ __u64 ino;
+ __u64 pid_tgid;
+ __u64 user_pid_tgid;
+} res;
+
+SEC("raw_tracepoint/sys_enter")
+int trace(void *ctx)
+{
+ __u64 ns_pid_tgid, expected_pid;
+ struct bpf_pidns_info nsdata;
+ __u32 key = 0;
+
+ if (bpf_get_ns_current_pid_tgid(res.dev, res.ino, &nsdata,
+ sizeof(struct bpf_pidns_info)))
+ return 0;
+
+ ns_pid_tgid = (__u64)nsdata.tgid << 32 | nsdata.pid;
+ expected_pid = res.user_pid_tgid;
+
+ if (expected_pid != ns_pid_tgid)
+ return 0;
+
+ res.pid_tgid = ns_pid_tgid;
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.20.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH v16 5/5] bpf_helpers_doc.py: Add struct bpf_pidns_info to known types
2019-12-18 17:38 [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task Carlos Neira
` (3 preceding siblings ...)
2019-12-18 17:38 ` [PATCH v16 4/5] tools/testing/selftests/bpf: Add self-tests for new helper bpf_get_ns_current_pid_tgid Carlos Neira
@ 2019-12-18 17:38 ` Carlos Neira
2019-12-19 18:43 ` Yonghong Song
2020-01-10 1:46 ` [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task Alexei Starovoitov
5 siblings, 1 reply; 13+ messages in thread
From: Carlos Neira @ 2019-12-18 17:38 UTC (permalink / raw)
To: netdev; +Cc: yhs, ebiederm, brouer, bpf, cneirabustos
Add struct bpf_pidns_info to known types
Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
---
scripts/bpf_helpers_doc.py | 1 +
1 file changed, 1 insertion(+)
diff --git a/scripts/bpf_helpers_doc.py b/scripts/bpf_helpers_doc.py
index 7548569e8076..021cc387d414 100755
--- a/scripts/bpf_helpers_doc.py
+++ b/scripts/bpf_helpers_doc.py
@@ -437,6 +437,7 @@ class PrinterHelpers(Printer):
'struct bpf_fib_lookup',
'struct bpf_perf_event_data',
'struct bpf_perf_event_value',
+ 'struct bpf_pidns_info',
'struct bpf_sock',
'struct bpf_sock_addr',
'struct bpf_sock_ops',
--
2.20.1
^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task
2019-12-18 17:38 [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task Carlos Neira
` (4 preceding siblings ...)
2019-12-18 17:38 ` [PATCH v16 5/5] bpf_helpers_doc.py: Add struct bpf_pidns_info to known types Carlos Neira
@ 2020-01-10 1:46 ` Alexei Starovoitov
2020-01-10 13:27 ` Carlos Antonio Neira Bustos
5 siblings, 1 reply; 13+ messages in thread
From: Alexei Starovoitov @ 2020-01-10 1:46 UTC (permalink / raw)
To: Carlos Neira
Cc: Network Development, Yonghong Song, Eric W. Biederman,
Jesper Dangaard Brouer, bpf, Daniel Borkmann
On Wed, Dec 18, 2019 at 9:38 AM Carlos Neira <cneirabustos@gmail.com> wrote:
>
> Currently bpf_get_current_pid_tgid(), is used to do pid filtering in bcc's
> scripts but this helper returns the pid as seen by the root namespace which is
> fine when a bcc script is not executed inside a container.
> When the process of interest is inside a container, pid filtering will not work
> if bpf_get_current_pid_tgid() is used.
> This helper addresses this limitation returning the pid as it's seen by the current
> namespace where the script is executing.
>
> In the future different pid_ns files may belong to different devices, according to the
> discussion between Eric Biederman and Yonghong in 2017 Linux plumbers conference.
> To address that situation the helper requires inum and dev_t from /proc/self/ns/pid.
> This helper has the same use cases as bpf_get_current_pid_tgid() as it can be
> used to do pid filtering even inside a container.
I think the set looks like fine. Please respin against bpf-next
carrying over Yonghong's ack and I'll apply it.
Please squash patch 2 and 3 together.
Updates to tools/uapi/bpf.h don't need to be separated anymore.
Patch 5 can be squashed into them as well.
Could you also improve selftest from patch 4 to test new helper
both inside and outside of some container?
With unshare(CLONE_NEWPID) or something.
Do you have corresponding bcc change to show how it's going to be used?
^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task
2020-01-10 1:46 ` [PATCH v16 0/5] BPF: New helper to obtain namespace data from current task Alexei Starovoitov
@ 2020-01-10 13:27 ` Carlos Antonio Neira Bustos
0 siblings, 0 replies; 13+ messages in thread
From: Carlos Antonio Neira Bustos @ 2020-01-10 13:27 UTC (permalink / raw)
To: Alexei Starovoitov
Cc: Network Development, Yonghong Song, Eric W. Biederman,
Jesper Dangaard Brouer, bpf, Daniel Borkmann
On Thu, Jan 09, 2020 at 05:46:29PM -0800, Alexei Starovoitov wrote:
> On Wed, Dec 18, 2019 at 9:38 AM Carlos Neira <cneirabustos@gmail.com> wrote:
> >
> > Currently bpf_get_current_pid_tgid(), is used to do pid filtering in bcc's
> > scripts but this helper returns the pid as seen by the root namespace which is
> > fine when a bcc script is not executed inside a container.
> > When the process of interest is inside a container, pid filtering will not work
> > if bpf_get_current_pid_tgid() is used.
> > This helper addresses this limitation returning the pid as it's seen by the current
> > namespace where the script is executing.
> >
> > In the future different pid_ns files may belong to different devices, according to the
> > discussion between Eric Biederman and Yonghong in 2017 Linux plumbers conference.
> > To address that situation the helper requires inum and dev_t from /proc/self/ns/pid.
> > This helper has the same use cases as bpf_get_current_pid_tgid() as it can be
> > used to do pid filtering even inside a container.
>
> I think the set looks like fine. Please respin against bpf-next
> carrying over Yonghong's ack and I'll apply it.
> Please squash patch 2 and 3 together.
> Updates to tools/uapi/bpf.h don't need to be separated anymore.
> Patch 5 can be squashed into them as well.
> Could you also improve selftest from patch 4 to test new helper
> both inside and outside of some container?
> With unshare(CLONE_NEWPID) or something.
> Do you have corresponding bcc change to show how it's going to be used?
Thanks Alexei,
I'll squash patches 2, 3, 5 together and improve the new helper test, regarding bcc
changes, I also need to work on that as the one I created a while ago now
is not valid https://github.com/iovisor/bcc/pull/1901/commits/a81b4352173cb82922d4d4bb965a39f781fd7693
Bests
^ permalink raw reply [flat|nested] 13+ messages in thread