Commit 85d05e28 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

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.

This patch is a first step converting IPv6 to the same strategy:

Before this patch inet6_sk_rebuild_header() only validated/rebuilt
a dst. Automatic variable @fl6 content was lost.

After this patch inet6_sk_rebuild_header() also initializes
inet->cork.fl.u.ip6, which can be reused in the future.

This makes inet6_sk_rebuild_header() very similar to
inet_sk_rebuild_header().

Also remove the EXPORT_SYMBOL_GPL(), inet6_sk_rebuild_header()
is not called from any module.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260204163035.4123817-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 047c5265

net/ipv6/af_inet6.c

+27 −30
Original line number Diff line number Diff line
@@ -824,33 +824,33 @@ EXPORT_SYMBOL(inet6_unregister_protosw); 
int inet6_sk_rebuild_header(struct sock *sk)

{

	struct ipv6_pinfo *np = inet6_sk(sk);

	struct inet_sock *inet = inet_sk(sk);

	struct in6_addr *final_p, final;

	struct dst_entry *dst;

	struct flowi6 *fl6;



	dst = __sk_dst_check(sk, np->dst_cookie);

	if (dst)

		return 0;



	if (!dst) {

		struct inet_sock *inet = inet_sk(sk);

		struct in6_addr *final_p, final;

		struct flowi6 fl6;



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

		fl6.flowi6_proto = sk->sk_protocol;

		fl6.daddr = sk->sk_v6_daddr;

		fl6.saddr = np->saddr;

		fl6.flowlabel = np->flow_label;

		fl6.flowi6_oif = sk->sk_bound_dev_if;

		fl6.flowi6_mark = sk->sk_mark;

		fl6.fl6_dport = inet->inet_dport;

		fl6.fl6_sport = inet->inet_sport;

		fl6.flowi6_uid = sk_uid(sk);

		security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6));

	fl6 = &inet->cork.fl.u.ip6;

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

	fl6->flowi6_proto = sk->sk_protocol;

	fl6->daddr = sk->sk_v6_daddr;

	fl6->saddr = np->saddr;

	fl6->flowlabel = np->flow_label;

	fl6->flowi6_oif = sk->sk_bound_dev_if;

	fl6->flowi6_mark = sk->sk_mark;

	fl6->fl6_dport = inet->inet_dport;

	fl6->fl6_sport = inet->inet_sport;

	fl6->flowi6_uid = sk_uid(sk);

	security_sk_classify_flow(sk, flowi6_to_flowi_common(fl6));



	rcu_read_lock();

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

					 &final);

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

	rcu_read_unlock();



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

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

	if (IS_ERR(dst)) {

		sk->sk_route_caps = 0;

		WRITE_ONCE(sk->sk_err_soft, -PTR_ERR(dst));
@@ -858,11 +858,8 @@ int inet6_sk_rebuild_header(struct sock *sk) 
	}



	ip6_dst_store(sk, dst, false, false);

	}



	return 0;

}

EXPORT_SYMBOL_GPL(inet6_sk_rebuild_header);



bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,

		       const struct inet6_skb_parm *opt)