Merge branch 'listener_refactor_16'

Eric Dumazet says:

====================
tcp: listener refactor part 16

A CONFIG_PROVE_RCU=y build revealed an RCU splat I had to fix.

I added const qualifiers to various md5 methods, as I expect
to call them on behalf of request sock traffic even if
the listener socket is not locked. This seems ok, but adding
const makes the contract clearer. Note a good reduction
of code size thanks to request/establish sockets convergence.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 36 deletions

diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 4a4e6d30c448..a9568caf4675 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -486,17 +486,11 @@ static struct tcp_md5sig_key *tcp_v6_md5_do_lookup(struct sock *sk,
 }
 
 static struct tcp_md5sig_key *tcp_v6_md5_lookup(struct sock *sk,
-						struct sock *addr_sk)
+						const struct sock *addr_sk)
 {
 	return tcp_v6_md5_do_lookup(sk, &addr_sk->sk_v6_daddr);
 }
 
-static struct tcp_md5sig_key *tcp_v6_reqsk_md5_lookup(struct sock *sk,
-						      struct request_sock *req)
-{
-	return tcp_v6_md5_do_lookup(sk, &inet_rsk(req)->ir_v6_rmt_addr);
-}
-
 static int tcp_v6_parse_md5_keys(struct sock *sk, char __user *optval,
 				 int optlen)
 {
@@ -582,9 +576,9 @@ clear_hash_noput:
 	return 1;
 }
 
-static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
+static int tcp_v6_md5_hash_skb(char *md5_hash,
+			       const struct tcp_md5sig_key *key,
 			       const struct sock *sk,
-			       const struct request_sock *req,
 			       const struct sk_buff *skb)
 {
 	const struct in6_addr *saddr, *daddr;
@@ -592,12 +586,9 @@ static int tcp_v6_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
 	struct hash_desc *desc;
 	const struct tcphdr *th = tcp_hdr(skb);
 
-	if (sk) {
-		saddr = &inet6_sk(sk)->saddr;
+	if (sk) { /* valid for establish/request sockets */
+		saddr = &sk->sk_v6_rcv_saddr;
 		daddr = &sk->sk_v6_daddr;
-	} else if (req) {
-		saddr = &inet_rsk(req)->ir_v6_loc_addr;
-		daddr = &inet_rsk(req)->ir_v6_rmt_addr;
 	} else {
 		const struct ipv6hdr *ip6h = ipv6_hdr(skb);
 		saddr = &ip6h->saddr;
@@ -633,8 +624,7 @@ clear_hash_noput:
 	return 1;
 }
 
-static int __tcp_v6_inbound_md5_hash(struct sock *sk,
-				     const struct sk_buff *skb)
+static bool tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
 {
 	const __u8 *hash_location = NULL;
 	struct tcp_md5sig_key *hash_expected;
@@ -648,44 +638,32 @@ static int __tcp_v6_inbound_md5_hash(struct sock *sk,
 
 	/* We've parsed the options - do we have a hash? */
 	if (!hash_expected && !hash_location)
-		return 0;
+		return false;
 
 	if (hash_expected && !hash_location) {
 		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5NOTFOUND);
-		return 1;
+		return true;
 	}
 
 	if (!hash_expected && hash_location) {
 		NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPMD5UNEXPECTED);
-		return 1;
+		return true;
 	}
 
 	/* check the signature */
 	genhash = tcp_v6_md5_hash_skb(newhash,
 				      hash_expected,
-				      NULL, NULL, skb);
+				      NULL, skb);
 
 	if (genhash || memcmp(hash_location, newhash, 16) != 0) {
 		net_info_ratelimited("MD5 Hash %s for [%pI6c]:%u->[%pI6c]:%u\n",
 				     genhash ? "failed" : "mismatch",
 				     &ip6h->saddr, ntohs(th->source),
 				     &ip6h->daddr, ntohs(th->dest));
-		return 1;
+		return true;
 	}
-	return 0;
+	return false;
 }
-
-static int tcp_v6_inbound_md5_hash(struct sock *sk, const struct sk_buff *skb)
-{
-	int ret;
-
-	rcu_read_lock();
-	ret = __tcp_v6_inbound_md5_hash(sk, skb);
-	rcu_read_unlock();
-
-	return ret;
-}
-
 #endif
 
 static void tcp_v6_init_req(struct request_sock *req, struct sock *sk,
@@ -736,7 +714,7 @@ static const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops = {
 	.mss_clamp	=	IPV6_MIN_MTU - sizeof(struct tcphdr) -
 				sizeof(struct ipv6hdr),
 #ifdef CONFIG_TCP_MD5SIG
-	.md5_lookup	=	tcp_v6_reqsk_md5_lookup,
+	.req_md5_lookup	=	tcp_v6_md5_lookup,
 	.calc_md5_hash	=	tcp_v6_md5_hash_skb,
 #endif
 	.init_req	=	tcp_v6_init_req,
@@ -893,7 +871,7 @@ static void tcp_v6_send_reset(struct sock *sk, struct sk_buff *skb)
 		if (!key)
 			goto release_sk1;
 
-		genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, NULL, skb);
+		genhash = tcp_v6_md5_hash_skb(newhash, key, NULL, skb);
 		if (genhash || memcmp(hash_location, newhash, 16) != 0)
 			goto release_sk1;
 	} else {