Add a eBPF helper function to retrieve socket uid
Returns the owner uid of the socket inside a sk_buff. This is useful to
perform per-UID accounting of network traffic or per-UID packet
filtering. The socket need to be a fullsock otherwise overflowuid is
returned.
Signed-off-by: Chenbo Feng <fengc@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index cdfc559..28317a0 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -465,6 +465,12 @@ union bpf_attr {
* @skb: pointer to skb
* Return: 8 Bytes non-decreasing number on success or 0 if the socket
* field is missing inside sk_buff
+ *
+ * u32 bpf_get_socket_uid(skb)
+ * Get the owner uid of the socket stored inside sk_buff.
+ * @skb: pointer to skb
+ * Return: uid of the socket owner on success or 0 if the socket pointer
+ * inside sk_buff is NULL
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -513,7 +519,8 @@ union bpf_attr {
FN(skb_change_head), \
FN(xdp_adjust_head), \
FN(probe_read_str), \
- FN(get_socket_cookie),
+ FN(get_socket_cookie), \
+ FN(get_socket_uid),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call