Commit 659affdb authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: add drop reasons to tcp_rcv_synsent_state_process() 



Re-use existing reasons.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c337578a

net/ipv4/tcp_input.c

+9 −6
Original line number Diff line number Diff line
@@ -6144,6 +6144,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, 
	struct tcp_fastopen_cookie foc = { .len = -1 };

	int saved_clamp = tp->rx_opt.mss_clamp;

	bool fastopen_fail;

	SKB_DR(reason);



	tcp_parse_options(sock_net(sk), skb, &tp->rx_opt, 0, &foc);

	if (tp->rx_opt.saw_tstamp && tp->rx_opt.rcv_tsecr)
@@ -6198,9 +6199,10 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, 
		 *    See note below!

		 *                                        --ANK(990513)

		 */

		if (!th->syn)

		if (!th->syn) {

			SKB_DR_SET(reason, TCP_FLAGS);

			goto discard_and_undo;



		}

		/* rfc793:

		 *   "If the SYN bit is on ...

		 *    are acceptable then ...
@@ -6291,15 +6293,16 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, 
		 *

		 *      Otherwise (no ACK) drop the segment and return."

		 */



		SKB_DR_SET(reason, TCP_RESET);

		goto discard_and_undo;

	}



	/* PAWS check. */

	if (tp->rx_opt.ts_recent_stamp && tp->rx_opt.saw_tstamp &&

	    tcp_paws_reject(&tp->rx_opt, 0))

	    tcp_paws_reject(&tp->rx_opt, 0)) {

		SKB_DR_SET(reason, TCP_RFC7323_PAWS);

		goto discard_and_undo;



	}

	if (th->syn) {

		/* We see SYN without ACK. It is attempt of

		 * simultaneous connect with crossed SYNs.
@@ -6358,7 +6361,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb, 
discard_and_undo:

	tcp_clear_options(&tp->rx_opt);

	tp->rx_opt.mss_clamp = saved_clamp;

	tcp_drop(sk, skb);

	tcp_drop_reason(sk, skb, reason);

	return 0;



reset_and_undo: