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authorEric Dumazet <edumazet@google.com>2022-04-15 17:10:46 -0700
committerDavid S. Miller <davem@davemloft.net>2022-04-17 13:31:31 +0100
commitc337578a6592d671c5e78accc55f00cc594fe2da (patch)
tree5b5477b8b3659e334f411c02d952d7eb2255c109
parente7c89ae4078eab24af71ba26b91642e819a4bd7f (diff)
downloadnet-next-c337578a6592d671c5e78accc55f00cc594fe2da.tar.gz
tcp: make tcp_rcv_synsent_state_process() drop monitor friend
1) A valid RST packet should be consumed, to not confuse drop monitor. 2) Same remark for packet validating cross syn setup, even if we might ignore part of it. 3) When third packet of 3WHS is delayed, do not pretend the SYNACK was dropped. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv4/tcp_input.c17
1 files changed, 8 insertions, 9 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index a1077adeb1b62d..cd9f5c39f85a04 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -6186,7 +6186,9 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
if (th->rst) {
tcp_reset(sk, skb);
- goto discard;
+consume:
+ __kfree_skb(skb);
+ return 0;
}
/* rfc793:
@@ -6275,13 +6277,9 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
tcp_enter_quickack_mode(sk, TCP_MAX_QUICKACKS);
inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK,
TCP_DELACK_MAX, TCP_RTO_MAX);
-
-discard:
- tcp_drop(sk, skb);
- return 0;
- } else {
- tcp_send_ack(sk);
+ goto consume;
}
+ tcp_send_ack(sk);
return -1;
}
@@ -6350,7 +6348,7 @@ discard:
*/
return -1;
#else
- goto discard;
+ goto consume;
#endif
}
/* "fifth, if neither of the SYN or RST bits is set then
@@ -6360,7 +6358,8 @@ discard:
discard_and_undo:
tcp_clear_options(&tp->rx_opt);
tp->rx_opt.mss_clamp = saved_clamp;
- goto discard;
+ tcp_drop(sk, skb);
+ return 0;
reset_and_undo:
tcp_clear_options(&tp->rx_opt);