diff mbox series

[bpf-next,v10,3/4] tools: Added bpf_get_current_pidns_info helper.

Message ID 20190906150952.23066-4-cneirabustos@gmail.com
State Changes Requested
Delegated to: BPF Maintainers
Headers show
Series [bpf-next,v10,1/4] fs/namei.c: make available filename_lookup() for bpf helpers. | expand

Commit Message

Carlos Antonio Neira Bustos Sept. 6, 2019, 3:09 p.m. UTC 
Signed-off-by: Carlos Neira <cneirabustos@gmail.com>
---
 tools/include/uapi/linux/bpf.h | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index b5889257cc33..3ec9aa1438b7 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -2747,6 +2747,32 @@  union bpf_attr {
  *		**-EOPNOTSUPP** kernel configuration does not enable SYN cookies
  *
  *		**-EPROTONOSUPPORT** IP packet version is not 4 or 6
+ *
+ * int bpf_get_current_pidns_info(struct bpf_pidns_info *pidns, u32 size_of_pidns)
+ *	Description
+ *		Get tgid, pid and namespace id as seen by the current namespace,
+ *		and device major/minor numbers from /proc/self/ns/pid. Such
+ *		information is stored in *pidns* of size *size*.
+ *
+ *		This helper is used when pid filtering is needed inside a
+ *		container as bpf_get_current_tgid() helper always returns the
+ *		pid id as seen by the root namespace.
+ *	Return
+ *		0 on success
+ *
+ *		On failure, the returned value is one of the following:
+ *
+ *		**-EINVAL** if *size_of_pidns* is not valid or unable to get ns, pid
+ *		or tgid of the current task.
+ *
+ *		**-ENOENT** if /proc/self/ns/pid does not exists.
+ *
+ *		**-ENOENT** if /proc/self/ns does not exists.
+ *
+ *		**-ENOMEM** if helper internal allocation fails.
+ *
+ *		**-EPERM** if not able to call helper.
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -2859,7 +2885,8 @@  union bpf_attr {
 	FN(sk_storage_get),		\
 	FN(sk_storage_delete),		\
 	FN(send_signal),		\
-	FN(tcp_gen_syncookie),
+	FN(tcp_gen_syncookie),		\
+	FN(get_current_pidns_info),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -3610,4 +3637,10 @@  struct bpf_sockopt {
 	__s32	retval;
 };
 
+struct bpf_pidns_info {
+	__u32 dev;	/* dev_t from /proc/self/ns/pid inode */
+	__u32 nsid;
+	__u32 tgid;
+	__u32 pid;
+};
 #endif /* _UAPI__LINUX_BPF_H__ */