Commit 19bdb267 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

tcp: populate inet->cork.fl.u.ip6 in tcp_v6_connect() 



Instead of using private @fl6 and @final variables
use respectively inet->cork.fl.u.ip6 and np->final.

As explained in commit 85d05e28 ("ipv6: change inet6_sk_rebuild_header()
to use inet->cork.fl.u.ip6"):

TCP v6 spends a good amount of time rebuilding a fresh fl6 at each
transmit in inet6_csk_xmit()/inet6_csk_route_socket().

TCP v4 caches the information in inet->cork.fl.u.ip4 instead.

After this patch, active TCP ipv6 flows have correctly initialized
inet->cork.fl.u.ip6 structure.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260206173426.1638518-6-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 969a2019

net/ipv6/tcp_ipv6.c

+24 −23
Original line number Diff line number Diff line
@@ -138,15 +138,15 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr_unsized *uaddr, 
{

	struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr;

	struct inet_connection_sock *icsk = inet_csk(sk);

	struct in6_addr *saddr = NULL, *final_p, final;

	struct inet_timewait_death_row *tcp_death_row;

	struct ipv6_pinfo *np = tcp_inet6_sk(sk);

	struct in6_addr *saddr = NULL, *final_p;

	struct inet_sock *inet = inet_sk(sk);

	struct tcp_sock *tp = tcp_sk(sk);

	struct net *net = sock_net(sk);

	struct ipv6_txoptions *opt;

	struct dst_entry *dst;

	struct flowi6 fl6;

	struct flowi6 *fl6;

	int addr_type;

	int err;
@@ -156,14 +156,15 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr_unsized *uaddr, 
	if (usin->sin6_family != AF_INET6)

		return -EAFNOSUPPORT;



	memset(&fl6, 0, sizeof(fl6));

	fl6 = &inet_sk(sk)->cork.fl.u.ip6;

	memset(fl6, 0, sizeof(*fl6));



	if (inet6_test_bit(SNDFLOW, sk)) {

		fl6.flowlabel = usin->sin6_flowinfo&IPV6_FLOWINFO_MASK;

		IP6_ECN_flow_init(fl6.flowlabel);

		if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) {

		fl6->flowlabel = usin->sin6_flowinfo & IPV6_FLOWINFO_MASK;

		IP6_ECN_flow_init(fl6->flowlabel);

		if (fl6->flowlabel & IPV6_FLOWLABEL_MASK) {

			struct ip6_flowlabel *flowlabel;

			flowlabel = fl6_sock_lookup(sk, fl6.flowlabel);

			flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);

			if (IS_ERR(flowlabel))

				return -EINVAL;

			fl6_sock_release(flowlabel);
@@ -212,7 +213,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr_unsized *uaddr, 
	}



	sk->sk_v6_daddr = usin->sin6_addr;

	np->flow_label = fl6.flowlabel;

	np->flow_label = fl6->flowlabel;



	/*

	 *	TCP over IPv4
@@ -260,24 +261,24 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr_unsized *uaddr, 
	if (!ipv6_addr_any(&sk->sk_v6_rcv_saddr))

		saddr = &sk->sk_v6_rcv_saddr;



	fl6.flowi6_proto = IPPROTO_TCP;

	fl6.daddr = sk->sk_v6_daddr;

	fl6.saddr = saddr ? *saddr : np->saddr;

	fl6.flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);

	fl6.flowi6_oif = sk->sk_bound_dev_if;

	fl6.flowi6_mark = sk->sk_mark;

	fl6.fl6_dport = usin->sin6_port;

	fl6.fl6_sport = inet->inet_sport;

	if (IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) && !fl6.fl6_sport)

		fl6.flowi6_flags = FLOWI_FLAG_ANY_SPORT;

	fl6.flowi6_uid = sk_uid(sk);

	fl6->flowi6_proto = IPPROTO_TCP;

	fl6->daddr = sk->sk_v6_daddr;

	fl6->saddr = saddr ? *saddr : np->saddr;

	fl6->flowlabel = ip6_make_flowinfo(np->tclass, np->flow_label);

	fl6->flowi6_oif = sk->sk_bound_dev_if;

	fl6->flowi6_mark = sk->sk_mark;

	fl6->fl6_dport = usin->sin6_port;

	fl6->fl6_sport = inet->inet_sport;

	if (IS_ENABLED(CONFIG_IP_ROUTE_MULTIPATH) && !fl6->fl6_sport)

		fl6->flowi6_flags = FLOWI_FLAG_ANY_SPORT;

	fl6->flowi6_uid = sk_uid(sk);



	opt = rcu_dereference_protected(np->opt, lockdep_sock_is_held(sk));

	final_p = fl6_update_dst(&fl6, opt, &final);

	final_p = fl6_update_dst(fl6, opt, &np->final);



	security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));

	security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));



	dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);

	dst = ip6_dst_lookup_flow(net, sk, fl6, final_p);

	if (IS_ERR(dst)) {

		err = PTR_ERR(dst);

		goto failure;
@@ -287,7 +288,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr_unsized *uaddr, 
	tcp_death_row = &sock_net(sk)->ipv4.tcp_death_row;



	if (!saddr) {

		saddr = &fl6.saddr;

		saddr = &fl6->saddr;



		err = inet_bhash2_update_saddr(sk, saddr, AF_INET6);

		if (err)