tcp: Cache sock_net(sk) in cookie_v[46]_check().

sock_net(sk) is used repeatedly in cookie_v[46]_check().
Let's cache it in a variable.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-3-kuniyu@amazon.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

net/ipv4/syncookies.c

@@ -336,6 +336,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 	struct tcp_options_received tcp_opt;
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct inet_request_sock *ireq;
+	struct net *net = sock_net(sk);
 	struct tcp_request_sock *treq;
 	struct request_sock *req;
 	struct sock *ret = sk;
@@ -346,7 +347,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 	u32 tsoff = 0;
 	int l3index;
 
-	if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) ||
+	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
 	    !th->ack || th->rst)
 		goto out;
 
@@ -355,24 +356,24 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 
 	mss = __cookie_v4_check(ip_hdr(skb), th, cookie);
 	if (mss == 0) {
-		__NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED);
+		__NET_INC_STATS(net, LINUX_MIB_SYNCOOKIESFAILED);
 		goto out;
 	}
 
-	__NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV);
+	__NET_INC_STATS(net, LINUX_MIB_SYNCOOKIESRECV);
 
 	/* check for timestamp cookie support */
 	memset(&tcp_opt, 0, sizeof(tcp_opt));
-	tcp_parse_options(sock_net(sk), skb, &tcp_opt, 0, NULL);
+	tcp_parse_options(net, skb, &tcp_opt, 0, NULL);
 
 	if (tcp_opt.saw_tstamp && tcp_opt.rcv_tsecr) {
-		tsoff = secure_tcp_ts_off(sock_net(sk),
+		tsoff = secure_tcp_ts_off(net,
 					  ip_hdr(skb)->daddr,
 					  ip_hdr(skb)->saddr);
 		tcp_opt.rcv_tsecr -= tsoff;
 	}
 
-	if (!cookie_timestamp_decode(sock_net(sk), &tcp_opt))
+	if (!cookie_timestamp_decode(net, &tcp_opt))
 		goto out;
 
 	ret = NULL;
@@ -406,13 +407,13 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 
 	ireq->ir_iif = inet_request_bound_dev_if(sk, skb);
 
-	l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
+	l3index = l3mdev_master_ifindex_by_index(net, ireq->ir_iif);
 	tcp_ao_syncookie(sk, skb, treq, AF_INET, l3index);
 
 	/* We throwed the options of the initial SYN away, so we hope
 	 * the ACK carries the same options again (see RFC1122 4.2.3.8)
 	 */
-	RCU_INIT_POINTER(ireq->ireq_opt, tcp_v4_save_options(sock_net(sk), skb));
+	RCU_INIT_POINTER(ireq->ireq_opt, tcp_v4_save_options(net, skb));
 
 	if (security_inet_conn_request(sk, skb, req)) {
 		reqsk_free(req);
@@ -433,7 +434,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 			   opt->srr ? opt->faddr : ireq->ir_rmt_addr,
 			   ireq->ir_loc_addr, th->source, th->dest, sk->sk_uid);
 	security_req_classify_flow(req, flowi4_to_flowi_common(&fl4));
-	rt = ip_route_output_key(sock_net(sk), &fl4);
+	rt = ip_route_output_key(net, &fl4);
 	if (IS_ERR(rt)) {
 		reqsk_free(req);
 		goto out;
@@ -453,7 +454,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
 				  dst_metric(&rt->dst, RTAX_INITRWND));
 
 	ireq->rcv_wscale  = rcv_wscale;
-	ireq->ecn_ok = cookie_ecn_ok(&tcp_opt, sock_net(sk), &rt->dst);
+	ireq->ecn_ok = cookie_ecn_ok(&tcp_opt, net, &rt->dst);
 
 	ret = tcp_get_cookie_sock(sk, skb, req, &rt->dst, tsoff);
 	/* ip_queue_xmit() depends on our flow being setup

net/ipv6/syncookies.c

@@ -133,6 +133,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 	struct tcp_options_received tcp_opt;
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct inet_request_sock *ireq;
+	struct net *net = sock_net(sk);
 	struct tcp_request_sock *treq;
 	struct request_sock *req;
 	struct dst_entry *dst;
@@ -142,7 +143,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 	u32 tsoff = 0;
 	int l3index;
 
-	if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) ||
+	if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
 	    !th->ack || th->rst)
 		goto out;
 
@@ -151,24 +152,24 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 
 	mss = __cookie_v6_check(ipv6_hdr(skb), th, cookie);
 	if (mss == 0) {
-		__NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED);
+		__NET_INC_STATS(net, LINUX_MIB_SYNCOOKIESFAILED);
 		goto out;
 	}
 
-	__NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV);
+	__NET_INC_STATS(net, LINUX_MIB_SYNCOOKIESRECV);
 
 	/* check for timestamp cookie support */
 	memset(&tcp_opt, 0, sizeof(tcp_opt));
-	tcp_parse_options(sock_net(sk), skb, &tcp_opt, 0, NULL);
+	tcp_parse_options(net, skb, &tcp_opt, 0, NULL);
 
 	if (tcp_opt.saw_tstamp && tcp_opt.rcv_tsecr) {
-		tsoff = secure_tcpv6_ts_off(sock_net(sk),
+		tsoff = secure_tcpv6_ts_off(net,
 					    ipv6_hdr(skb)->daddr.s6_addr32,
 					    ipv6_hdr(skb)->saddr.s6_addr32);
 		tcp_opt.rcv_tsecr -= tsoff;
 	}
 
-	if (!cookie_timestamp_decode(sock_net(sk), &tcp_opt))
+	if (!cookie_timestamp_decode(net, &tcp_opt))
 		goto out;
 
 	ret = NULL;
@@ -217,7 +218,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 	treq->ts_off = 0;
 	treq->txhash = net_tx_rndhash();
 
-	l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);
+	l3index = l3mdev_master_ifindex_by_index(net, ireq->ir_iif);
 	tcp_ao_syncookie(sk, skb, treq, AF_INET6, l3index);
 
 	if (IS_ENABLED(CONFIG_SMC))
@@ -243,7 +244,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 		fl6.flowi6_uid = sk->sk_uid;
 		security_req_classify_flow(req, flowi6_to_flowi_common(&fl6));
 
-		dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
+		dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);
 		if (IS_ERR(dst))
 			goto out_free;
 	}
@@ -261,7 +262,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
 				  dst_metric(dst, RTAX_INITRWND));
 
 	ireq->rcv_wscale = rcv_wscale;
-	ireq->ecn_ok = cookie_ecn_ok(&tcp_opt, sock_net(sk), dst);
+	ireq->ecn_ok = cookie_ecn_ok(&tcp_opt, net, dst);
 
 	ret = tcp_get_cookie_sock(sk, skb, req, dst, tsoff);
 out: