Messages in this thread Patch in this message | | | From | menglong8.dong@gmail ... | Subject | [PATCH net-next 5/9] net: tcp: make tcp_rcv_synsent_state_process() return drop reasons | Date | Mon, 16 May 2022 11:45:15 +0800 |
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From: Menglong Dong <imagedong@tencent.com>
The return value of tcp_rcv_synsent_state_process() can be -1, 0 or 1:
- -1: free skb silently - 0: success and skb is already freed - 1: drop packet and send a RST
Therefore, we can make it return skb drop reasons on 'reset_and_undo' path, which will not impact the caller.
The new reason 'TCP_PAWSACTIVEREJECTED' is added, which is corresponding to LINUX_MIB_PAWSACTIVEREJECTED.
Signed-off-by: Menglong Dong <imagedong@tencent.com> --- include/linux/skbuff.h | 1 + net/ipv4/tcp_input.c | 7 ++++++- 2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 3c7b1e9aabbb..36e0971f4cc9 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -619,6 +619,7 @@ struct sk_buff; FN(IP_INNOROUTES) \ FN(PKT_TOO_BIG) \ FN(SOCKET_DESTROYED) \ + FN(TCP_PAWSACTIVEREJECTED) \ FN(MAX) /* The reason of skb drop, which is used in kfree_skb_reason(). diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 97cfcd85f84e..e8d26a68bc45 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6174,6 +6174,10 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, TCP_TIMEOUT_MIN, TCP_RTO_MAX); + if (after(TCP_SKB_CB(skb)->ack_seq, tp->snd_nxt)) + SKB_DR_SET(reason, TCP_ACK_UNSENT_DATA); + else + SKB_DR_SET(reason, TCP_TOO_OLD_ACK); goto reset_and_undo; } @@ -6182,6 +6186,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, tcp_time_stamp(tp))) { NET_INC_STATS(sock_net(sk), LINUX_MIB_PAWSACTIVEREJECTED); + SKB_DR_SET(reason, TCP_PAWSACTIVEREJECTED); goto reset_and_undo; } @@ -6375,7 +6380,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, reset_and_undo: tcp_clear_options(&tp->rx_opt); tp->rx_opt.mss_clamp = saved_clamp; - return 1; + return reason; } static void tcp_rcv_synrecv_state_fastopen(struct sock *sk) -- 2.36.1
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