On 03/20/2017 07:41 PM, Chenbo Feng wrote:
From: Chenbo Feng <fe...@google.com>
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 <fe...@google.com>
---
include/uapi/linux/bpf.h | 9 ++++++++-
net/core/filter.c | 22 ++++++++++++++++++++++
tools/include/uapi/linux/bpf.h | 3 ++-
3 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index dc81a9f..ff42111 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -462,6 +462,12 @@ 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), \
@@ -510,7 +516,8 @@ 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
diff --git a/net/core/filter.c b/net/core/filter.c
index 5b65ae3..a7c25c1 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2612,6 +2612,24 @@ static const struct bpf_func_proto
bpf_get_socket_cookie_proto = {
.arg1_type = ARG_PTR_TO_CTX,
};
+BPF_CALL_1(bpf_get_socket_uid, struct sk_buff *, skb)
+{
+ kuid_t kuid;
+ struct sock *sk = sk_to_full_sk(skb->sk);
Minor nit, please change the order into:
struct sock *sk = sk_to_full_sk(skb->sk);
kuid_t kuid;
+ if (!sk || !sk_fullsock(sk))
+ return overflowuid;
+ kuid = sock_net_uid(sock_net(sk), sk);
+ return from_kuid_munged(current_user_ns(), kuid);
+}
+
+static const struct bpf_func_proto bpf_get_socket_uid_proto = {
+ .func = bpf_get_socket_uid,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+};
+
Rest looks good, thanks.
Acked-by: Daniel Borkmann <dan...@iogearbox.net>
