diff options
| author | Jason Xing <kernelxing@tencent.com> | 2024-04-01 15:36:05 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-04-03 19:26:14 -0700 |
| commit | 19822a980e1956a6572998887a7df5a0607a32f6 (patch) | |
| tree | ff2abee2b5fd4ec8a9c22967bb598596555c6266 /net/ipv4 | |
| parent | 9807080e2170a9e5a7428d0a0e8d082585b6451f (diff) | |
trace: tcp: fully support trace_tcp_send_reset
Prior to this patch, what we can see by enabling trace_tcp_send is
only happening under two circumstances:
1) active rst mode
2) non-active rst mode and based on the full socket
That means the inconsistency occurs if we use tcpdump and trace
simultaneously to see how rst happens.
It's necessary that we should take into other cases into considerations,
say:
1) time-wait socket
2) no socket
...
By parsing the incoming skb and reversing its 4-tuple can
we know the exact 'flow' which might not exist.
Samples after applied this patch:
1. tcp_send_reset: skbaddr=XXX skaddr=XXX src=ip:port dest=ip:port
state=TCP_ESTABLISHED
2. tcp_send_reset: skbaddr=000...000 skaddr=XXX src=ip:port dest=ip:port
state=UNKNOWN
Note:
1) UNKNOWN means we cannot extract the right information from skb.
2) skbaddr/skaddr could be 0
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Link: https://lore.kernel.org/r/20240401073605.37335-3-kerneljasonxing@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 1e0a9762f92e..56b75efcfd12 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -866,11 +866,10 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) * routing might fail in this case. No choice here, if we choose to force * input interface, we will misroute in case of asymmetric route. */ - if (sk) { + if (sk) arg.bound_dev_if = sk->sk_bound_dev_if; - if (sk_fullsock(sk)) - trace_tcp_send_reset(sk, skb); - } + + trace_tcp_send_reset(sk, skb); BUILD_BUG_ON(offsetof(struct sock, sk_bound_dev_if) != offsetof(struct inet_timewait_sock, tw_bound_dev_if)); |