Commit a6eee39c authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

tcp: populate inet->cork.fl.u.ip6 in tcp_v6_syn_recv_sock() 



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, passive 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/20260206173426.1638518-7-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 19bdb267

include/net/inet6_connection_sock.h

+3 −1
Original line number Diff line number Diff line
@@ -18,7 +18,9 @@ struct sk_buff; 
struct sock;

struct sockaddr;



struct dst_entry *inet6_csk_route_req(const struct sock *sk, struct flowi6 *fl6,

struct dst_entry *inet6_csk_route_req(const struct sock *sk,

				      struct dst_entry *dst,

				      struct flowi6 *fl6,

				      const struct request_sock *req, u8 proto);



int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);

net/ipv6/inet6_connection_sock.c

+6 −5
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <net/sock_reuseport.h>



struct dst_entry *inet6_csk_route_req(const struct sock *sk,

				      struct dst_entry *dst,

				      struct flowi6 *fl6,

				      const struct request_sock *req,

				      u8 proto)
@@ -32,7 +33,6 @@ struct dst_entry *inet6_csk_route_req(const struct sock *sk, 
	const struct inet_request_sock *ireq = inet_rsk(req);

	const struct ipv6_pinfo *np = inet6_sk(sk);

	struct in6_addr *final_p, final;

	struct dst_entry *dst;



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

	fl6->flowi6_proto = proto;
@@ -48,10 +48,11 @@ struct dst_entry *inet6_csk_route_req(const struct sock *sk, 
	fl6->flowi6_uid = sk_uid(sk);

	security_req_classify_flow(req, flowi6_to_flowi_common(fl6));



	if (!dst) {

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

		if (IS_ERR(dst))

			return NULL;



	}

	return dst;

}

net/ipv6/tcp_ipv6.c

+8 −9
Original line number Diff line number Diff line
@@ -539,7 +539,7 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst, 
	u8 tclass;



	/* First, grab a route. */

	if (!dst && (dst = inet6_csk_route_req(sk, fl6, req,

	if (!dst && (dst = inet6_csk_route_req(sk, NULL, fl6, req,

					       IPPROTO_TCP)) == NULL)

		goto done;
@@ -789,7 +789,7 @@ static struct dst_entry *tcp_v6_route_req(const struct sock *sk, 
	if (security_inet_conn_request(sk, skb, req))

		return NULL;



	return inet6_csk_route_req(sk, &fl->u.ip6, req, IPPROTO_TCP);

	return inet6_csk_route_req(sk, NULL, &fl->u.ip6, req, IPPROTO_TCP);

}



struct request_sock_ops tcp6_request_sock_ops __read_mostly = {
@@ -1318,12 +1318,12 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * 
					 struct request_sock *req_unhash,

					 bool *own_req)

{

	struct inet_request_sock *ireq;

	struct ipv6_pinfo *newnp;

	const struct ipv6_pinfo *np = tcp_inet6_sk(sk);

	struct inet_request_sock *ireq;

	struct ipv6_txoptions *opt;

	struct inet_sock *newinet;

	bool found_dup_sk = false;

	struct ipv6_pinfo *newnp;

	struct tcp_sock *newtp;

	struct sock *newsk;

#ifdef CONFIG_TCP_MD5SIG
@@ -1392,11 +1392,9 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * 
	if (sk_acceptq_is_full(sk))

		goto exit_overflow;



	if (!dst) {

		dst = inet6_csk_route_req(sk, &fl6, req, IPPROTO_TCP);

	dst = inet6_csk_route_req(sk, dst, &fl6, req, IPPROTO_TCP);

	if (!dst)

		goto exit;

	}



	newsk = tcp_create_openreq_child(sk, req, skb);

	if (!newsk)
@@ -1412,6 +1410,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff * 
	inet6_sk_rx_dst_set(newsk, skb);



	newinet = inet_sk(newsk);

	newinet->cork.fl.u.ip6 = fl6;

	newinet->pinet6 = tcp_inet6_sk(newsk);

	newinet->ipv6_fl_list = NULL;

	newinet->inet_opt = NULL;