bpf: Added new helper bpf_get_ns_current_pid_tgid
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 <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 4fd91b7..4ec8353 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1497,6 +1497,7 @@ 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_jiffies64_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 40b2d94..15b239d 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2914,6 +2914,19 @@ union bpf_attr {
* of sizeof(struct perf_branch_entry).
*
* **-ENOENT** if architecture does not support branch records.
+ *
+ * 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), \
@@ -3035,7 +3048,8 @@ union bpf_attr {
FN(tcp_send_ack), \
FN(send_signal_thread), \
FN(jiffies64), \
- FN(read_branch_records),
+ FN(read_branch_records), \
+ FN(get_ns_current_pid_tgid),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
@@ -3829,4 +3843,8 @@ struct bpf_sockopt {
__s32 retval;
};
+struct bpf_pidns_info {
+ __u32 pid;
+ __u32 tgid;
+};
#endif /* _UAPI__LINUX_BPF_H__ */
