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Commit 065263f4 authored by Wei Wang's avatar Wei Wang Committed by David S. Miller
Browse files

net/tcp-fastopen: refactor cookie check logic 



Refactor the cookie check logic in tcp_send_syn_data() into a function.
This function will be called else where in later changes.

Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Acked-by: default avatarYuchung Cheng <ycheng@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a9c54ad2

include/net/tcp.h

+2 −0
Original line number Diff line number Diff line
@@ -1493,6 +1493,8 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, 
			      struct tcp_fastopen_cookie *foc,

			      struct dst_entry *dst);

void tcp_fastopen_init_key_once(bool publish);

bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss,

			     struct tcp_fastopen_cookie *cookie);

#define TCP_FASTOPEN_KEY_LENGTH 16



/* Fastopen key context */

net/ipv4/tcp_fastopen.c

+21 −0
Original line number Diff line number Diff line
@@ -325,3 +325,24 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, 
	*foc = valid_foc;

	return NULL;

}



bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss,

			       struct tcp_fastopen_cookie *cookie)

{

	unsigned long last_syn_loss = 0;

	int syn_loss = 0;



	tcp_fastopen_cache_get(sk, mss, cookie, &syn_loss, &last_syn_loss);



	/* Recurring FO SYN losses: no cookie or data in SYN */

	if (syn_loss > 1 &&

	    time_before(jiffies, last_syn_loss + (60*HZ << syn_loss))) {

		cookie->len = -1;

		return false;

	}

	if (sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE) {

		cookie->len = -1;

		return true;

	}

	return cookie->len > 0;

}

net/ipv4/tcp_output.c

+2 −14
Original line number Diff line number Diff line
@@ -3267,23 +3267,11 @@ static int tcp_send_syn_data(struct sock *sk, struct sk_buff *syn) 
{

	struct tcp_sock *tp = tcp_sk(sk);

	struct tcp_fastopen_request *fo = tp->fastopen_req;

	int syn_loss = 0, space, err = 0;

	unsigned long last_syn_loss = 0;

	int space, err = 0;

	struct sk_buff *syn_data;



	tp->rx_opt.mss_clamp = tp->advmss;  /* If MSS is not cached */

	tcp_fastopen_cache_get(sk, &tp->rx_opt.mss_clamp, &fo->cookie,

			       &syn_loss, &last_syn_loss);

	/* Recurring FO SYN losses: revert to regular handshake temporarily */

	if (syn_loss > 1 &&

	    time_before(jiffies, last_syn_loss + (60*HZ << syn_loss))) {

		fo->cookie.len = -1;

		goto fallback;

	}



	if (sysctl_tcp_fastopen & TFO_CLIENT_NO_COOKIE)

		fo->cookie.len = -1;

	else if (fo->cookie.len <= 0)

	if (!tcp_fastopen_cookie_check(sk, &tp->rx_opt.mss_clamp, &fo->cookie))

		goto fallback;



	/* MSS for SYN-data is based on cached MSS and bounded by PMTU and