Commit be372e91 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'tcp-tcp_v4_err-cleanups' 



Eric Dumazet says:

====================
tcp: tcp_v4_err() cleanups

This series is a followup of patch 23917494 ("tcp: tcp_v4_err() icmp
skb is named icmp_skb").

Move the RFC 6069 code into a helper, and rename icmp_skb to standard
skb name so that tcp_v4_err() and tcp_v6_err() are using consistent names.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents d6a3511b a12daf13

net/ipv4/tcp_ipv4.c

+54 −49
Original line number Diff line number Diff line
@@ -403,6 +403,45 @@ void tcp_req_err(struct sock *sk, u32 seq, bool abort) 
}

EXPORT_SYMBOL(tcp_req_err);



/* TCP-LD (RFC 6069) logic */

static void tcp_ld_RTO_revert(struct sock *sk, u32 seq)

{

	struct inet_connection_sock *icsk = inet_csk(sk);

	struct tcp_sock *tp = tcp_sk(sk);

	struct sk_buff *skb;

	s32 remaining;

	u32 delta_us;



	if (sock_owned_by_user(sk))

		return;



	if (seq != tp->snd_una  || !icsk->icsk_retransmits ||

	    !icsk->icsk_backoff)

		return;



	skb = tcp_rtx_queue_head(sk);

	if (WARN_ON_ONCE(!skb))

		return;



	icsk->icsk_backoff--;

	icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) : TCP_TIMEOUT_INIT;

	icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX);



	tcp_mstamp_refresh(tp);

	delta_us = (u32)(tp->tcp_mstamp - tcp_skb_timestamp_us(skb));

	remaining = icsk->icsk_rto - usecs_to_jiffies(delta_us);



	if (remaining > 0) {

		inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,

					  remaining, TCP_RTO_MAX);

	} else {

		/* RTO revert clocked out retransmission.

		 * Will retransmit now.

		 */

		tcp_retransmit_timer(sk);

	}

}



/*

 * This routine is called by the ICMP module when it gets some

 * sort of error condition.  If err < 0 then the socket should
@@ -419,27 +458,23 @@ EXPORT_SYMBOL(tcp_req_err); 
 *

 */



int tcp_v4_err(struct sk_buff *icmp_skb, u32 info)

int tcp_v4_err(struct sk_buff *skb, u32 info)

{

	const struct iphdr *iph = (const struct iphdr *)icmp_skb->data;

	struct tcphdr *th = (struct tcphdr *)(icmp_skb->data + (iph->ihl << 2));

	struct inet_connection_sock *icsk;

	const struct iphdr *iph = (const struct iphdr *)skb->data;

	struct tcphdr *th = (struct tcphdr *)(skb->data + (iph->ihl << 2));

	struct tcp_sock *tp;

	struct inet_sock *inet;

	const int type = icmp_hdr(icmp_skb)->type;

	const int code = icmp_hdr(icmp_skb)->code;

	const int type = icmp_hdr(skb)->type;

	const int code = icmp_hdr(skb)->code;

	struct sock *sk;

	struct sk_buff *skb;

	struct request_sock *fastopen;

	u32 seq, snd_una;

	s32 remaining;

	u32 delta_us;

	int err;

	struct net *net = dev_net(icmp_skb->dev);

	struct net *net = dev_net(skb->dev);



	sk = __inet_lookup_established(net, &tcp_hashinfo, iph->daddr,

				       th->dest, iph->saddr, ntohs(th->source),

				       inet_iif(icmp_skb), 0);

				       inet_iif(skb), 0);

	if (!sk) {

		__ICMP_INC_STATS(net, ICMP_MIB_INERRORS);

		return -ENOENT;
@@ -476,7 +511,6 @@ int tcp_v4_err(struct sk_buff *icmp_skb, u32 info) 
		goto out;

	}



	icsk = inet_csk(sk);

	tp = tcp_sk(sk);

	/* XXX (TFO) - tp->snd_una should be ISN (tcp_create_openreq_child() */

	fastopen = rcu_dereference(tp->fastopen_rsk);
@@ -490,7 +524,7 @@ int tcp_v4_err(struct sk_buff *icmp_skb, u32 info) 
	switch (type) {

	case ICMP_REDIRECT:

		if (!sock_owned_by_user(sk))

			do_redirect(icmp_skb, sk);

			do_redirect(skb, sk);

		goto out;

	case ICMP_SOURCE_QUENCH:

		/* Just silently ignore these. */
@@ -521,41 +555,12 @@ int tcp_v4_err(struct sk_buff *icmp_skb, u32 info) 
		}



		err = icmp_err_convert[code].errno;

		/* check if icmp_skb allows revert of backoff

		 * (see draft-zimmermann-tcp-lcd) */

		if (code != ICMP_NET_UNREACH && code != ICMP_HOST_UNREACH)

			break;

		if (seq != tp->snd_una  || !icsk->icsk_retransmits ||

		    !icsk->icsk_backoff || fastopen)

			break;



		if (sock_owned_by_user(sk))

			break;



		skb = tcp_rtx_queue_head(sk);

		if (WARN_ON_ONCE(!skb))

			break;



		icsk->icsk_backoff--;

		icsk->icsk_rto = tp->srtt_us ? __tcp_set_rto(tp) :

					       TCP_TIMEOUT_INIT;

		icsk->icsk_rto = inet_csk_rto_backoff(icsk, TCP_RTO_MAX);





		tcp_mstamp_refresh(tp);

		delta_us = (u32)(tp->tcp_mstamp - tcp_skb_timestamp_us(skb));

		remaining = icsk->icsk_rto -

			    usecs_to_jiffies(delta_us);



		if (remaining > 0) {

			inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,

						  remaining, TCP_RTO_MAX);

		} else {

			/* RTO revert clocked out retransmission.

			 * Will retransmit now */

			tcp_retransmit_timer(sk);

		}



		/* check if this ICMP message allows revert of backoff.

		 * (see RFC 6069)

		 */

		if (!fastopen &&

		    (code == ICMP_NET_UNREACH || code == ICMP_HOST_UNREACH))

			tcp_ld_RTO_revert(sk, seq);

		break;

	case ICMP_TIME_EXCEEDED:

		err = EHOSTUNREACH;
@@ -573,7 +578,7 @@ int tcp_v4_err(struct sk_buff *icmp_skb, u32 info) 
		if (fastopen && !fastopen->sk)

			break;



		ip_icmp_error(sk, icmp_skb, err, th->dest, info, (u8 *)th);

		ip_icmp_error(sk, skb, err, th->dest, info, (u8 *)th);



		if (!sock_owned_by_user(sk)) {

			sk->sk_err = err;

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