| Message ID | 20200630221833.740761-1-kafai@fb.com |
|---|---|
| State | New |
| Headers | show |
| Series | [net] ipv4: tcp: Fix SO_MARK in RST and ACK packet | expand |
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 090d3097ee15..033512f719ec 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1703,6 +1703,7 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, sk->sk_bound_dev_if = arg->bound_dev_if; sk->sk_sndbuf = sysctl_wmem_default; sk->sk_mark = fl4.flowi4_mark; + ipc.sockc.mark = fl4.flowi4_mark; err = ip_append_data(sk, &fl4, ip_reply_glue_bits, arg->iov->iov_base, len, 0, &ipc, &rt, MSG_DONTWAIT); if (unlikely(err)) {
When testing a recent kernel (5.6 in our case), the skb->mark of the IPv4 TCP RST pkt does not carry the mark from sk->sk_mark. It is discovered by the bpf@tc that depends on skb->mark to work properly. The same bpf prog has been working in the earlier kernel version. After reverting commit c6af0c227a22 ("ip: support SO_MARK cmsg"), the skb->mark is set and seen by bpf@tc properly. We have noticed that in IPv4 TCP RST but it should also happen to the ACK based on tcp_v4_send_ack() is also depending on ip_send_unicast_reply(). This patch tries to fix it by initializing the ipc.sockc.mark to fl4.flowi4_mark. Fixes: c6af0c227a22 ("ip: support SO_MARK cmsg") Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: Martin KaFai Lau <kafai@fb.com> --- net/ipv4/ip_output.c | 1 + 1 file changed, 1 insertion(+)