Merge branch 'inet-better-inet_sock_set_state-for-passive-flows'

Eric Dumazet says:

====================
inet: better inet_sock_set_state() for passive flows

Small series to make inet_sock_set_state() more interesting for
LISTEN -> TCP_SYN_RECV changes : The 4-tuple parts are now correct.

First patch is a cleanup.
====================

Link: https://patch.msgid.link/20250212131328.1514243-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 48 insertions, 42 deletions

diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index be515ba821e2..bfa529a54aca 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -426,9 +426,6 @@ struct sock *dccp_v4_request_recv_sock(const struct sock *sk,
 
 	newinet		   = inet_sk(newsk);
 	ireq		   = inet_rsk(req);
-	sk_daddr_set(newsk, ireq->ir_rmt_addr);
-	sk_rcv_saddr_set(newsk, ireq->ir_loc_addr);
-	newinet->inet_saddr	= ireq->ir_loc_addr;
 	RCU_INIT_POINTER(newinet->inet_opt, rcu_dereference(ireq->ireq_opt));
 	newinet->mc_index  = inet_iif(skb);
 	newinet->mc_ttl	   = ip_hdr(skb)->ttl;
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index d6649246188d..39ae9d89d7d4 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -365,6 +365,9 @@ static int dccp_v6_conn_request(struct sock *sk, struct sk_buff *skb)
 	ireq = inet_rsk(req);
 	ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 	ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
+	ireq->ir_rmt_addr = LOOPBACK4_IPV6;
+	ireq->ir_loc_addr = LOOPBACK4_IPV6;
+
 	ireq->ireq_family = AF_INET6;
 	ireq->ir_mark = inet_request_mark(sk, skb);
 
@@ -504,10 +507,7 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
 
 	memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 
-	newsk->sk_v6_daddr	= ireq->ir_v6_rmt_addr;
 	newnp->saddr		= ireq->ir_v6_loc_addr;
-	newsk->sk_v6_rcv_saddr	= ireq->ir_v6_loc_addr;
-	newsk->sk_bound_dev_if	= ireq->ir_iif;
 
 	/* Now IPv6 options...
 
@@ -546,9 +546,6 @@ static struct sock *dccp_v6_request_recv_sock(const struct sock *sk,
 
 	dccp_sync_mss(newsk, dst_mtu(dst));
 
-	newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
-	newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
-
 	if (__inet_inherit_port(sk, newsk) < 0) {
 		inet_csk_prepare_forced_close(newsk);
 		dccp_done(newsk);
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 2b7775b90a09..bf9ce0c19657 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -1237,39 +1237,59 @@ struct sock *inet_csk_clone_lock(const struct sock *sk,
 				 const gfp_t priority)
 {
 	struct sock *newsk = sk_clone_lock(sk, priority);
+	struct inet_connection_sock *newicsk;
+	struct inet_request_sock *ireq;
+	struct inet_sock *newinet;
 
-	if (newsk) {
-		struct inet_connection_sock *newicsk = inet_csk(newsk);
+	if (!newsk)
+		return NULL;
 
-		inet_sk_set_state(newsk, TCP_SYN_RECV);
-		newicsk->icsk_bind_hash = NULL;
-		newicsk->icsk_bind2_hash = NULL;
+	newicsk = inet_csk(newsk);
+	newinet = inet_sk(newsk);
+	ireq = inet_rsk(req);
 
-		inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port;
-		inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num;
-		inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
+	newicsk->icsk_bind_hash = NULL;
+	newicsk->icsk_bind2_hash = NULL;
 
-		/* listeners have SOCK_RCU_FREE, not the children */
-		sock_reset_flag(newsk, SOCK_RCU_FREE);
+	newinet->inet_dport = ireq->ir_rmt_port;
+	newinet->inet_num = ireq->ir_num;
+	newinet->inet_sport = htons(ireq->ir_num);
 
-		inet_sk(newsk)->mc_list = NULL;
+	newsk->sk_bound_dev_if = ireq->ir_iif;
 
-		newsk->sk_mark = inet_rsk(req)->ir_mark;
-		atomic64_set(&newsk->sk_cookie,
-			     atomic64_read(&inet_rsk(req)->ir_cookie));
+	newsk->sk_daddr = ireq->ir_rmt_addr;
+	newsk->sk_rcv_saddr = ireq->ir_loc_addr;
+	newinet->inet_saddr = ireq->ir_loc_addr;
 
-		newicsk->icsk_retransmits = 0;
-		newicsk->icsk_backoff	  = 0;
-		newicsk->icsk_probes_out  = 0;
-		newicsk->icsk_probes_tstamp = 0;
+#if IS_ENABLED(CONFIG_IPV6)
+	newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
+	newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
+#endif
 
-		/* Deinitialize accept_queue to trap illegal accesses. */
-		memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue));
+	/* listeners have SOCK_RCU_FREE, not the children */
+	sock_reset_flag(newsk, SOCK_RCU_FREE);
 
-		inet_clone_ulp(req, newsk, priority);
+	inet_sk(newsk)->mc_list = NULL;
+
+	newsk->sk_mark = inet_rsk(req)->ir_mark;
+	atomic64_set(&newsk->sk_cookie,
+		     atomic64_read(&inet_rsk(req)->ir_cookie));
+
+	newicsk->icsk_retransmits = 0;
+	newicsk->icsk_backoff	  = 0;
+	newicsk->icsk_probes_out  = 0;
+	newicsk->icsk_probes_tstamp = 0;
+
+	/* Deinitialize accept_queue to trap illegal accesses. */
+	memset(&newicsk->icsk_accept_queue, 0,
+	       sizeof(newicsk->icsk_accept_queue));
+
+	inet_sk_set_state(newsk, TCP_SYN_RECV);
+
+	inet_clone_ulp(req, newsk, priority);
+
+	security_inet_csk_clone(newsk, req);
 
-		security_inet_csk_clone(newsk, req);
-	}
 	return newsk;
 }
 EXPORT_SYMBOL_GPL(inet_csk_clone_lock);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 6245e24fcbf3..f4a5e963a607 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1768,10 +1768,6 @@ struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
 	newtp		      = tcp_sk(newsk);
 	newinet		      = inet_sk(newsk);
 	ireq		      = inet_rsk(req);
-	sk_daddr_set(newsk, ireq->ir_rmt_addr);
-	sk_rcv_saddr_set(newsk, ireq->ir_loc_addr);
-	newsk->sk_bound_dev_if = ireq->ir_iif;
-	newinet->inet_saddr   = ireq->ir_loc_addr;
 	inet_opt	      = rcu_dereference(ireq->ireq_opt);
 	RCU_INIT_POINTER(newinet->inet_opt, inet_opt);
 	newinet->mc_index     = inet_iif(skb);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 2debdf085a3b..a80608260298 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -798,6 +798,8 @@ static void tcp_v6_init_req(struct request_sock *req,
 
 	ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
 	ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
+	ireq->ir_rmt_addr = LOOPBACK4_IPV6;
+	ireq->ir_loc_addr = LOOPBACK4_IPV6;
 
 	/* So that link locals have meaning */
 	if ((!sk_listener->sk_bound_dev_if || l3_slave) &&
@@ -1451,10 +1453,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
 
 	ip6_dst_store(newsk, dst, NULL, NULL);
 
-	newsk->sk_v6_daddr = ireq->ir_v6_rmt_addr;
 	newnp->saddr = ireq->ir_v6_loc_addr;
-	newsk->sk_v6_rcv_saddr = ireq->ir_v6_loc_addr;
-	newsk->sk_bound_dev_if = ireq->ir_iif;
 
 	/* Now IPv6 options...
 
@@ -1507,9 +1506,6 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
 
 	tcp_initialize_rcv_mss(newsk);
 
-	newinet->inet_daddr = newinet->inet_saddr = LOOPBACK4_IPV6;
-	newinet->inet_rcv_saddr = LOOPBACK4_IPV6;
-
 #ifdef CONFIG_TCP_MD5SIG
 	l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif);