tcp: Get rid of inetpeer special cases.

The get_peer method TCP uses is full of special cases that make no
sense accommodating, and it also gets in the way of doing more
reasonable things here.

First of all, if the socket doesn't have a usable cached route, there
is no sense in trying to optimize timewait recycling.

Likewise for the case where we have IP options, such as SRR enabled,
that make the IP header destination address (and thus the destination
address of the route key) differ from that of the connection's
destination address.

Just return a NULL peer in these cases, and thus we're also able to
get rid of the clumsy inetpeer release logic.

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

3 files changed, 17 insertions, 30 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 833e8d96a636..77f049d00dbb 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1820,23 +1820,18 @@ do_time_wait:
 	goto discard_it;
 }
 
-struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it)
+struct inet_peer *tcp_v4_get_peer(struct sock *sk)
 {
 	struct rtable *rt = (struct rtable *) __sk_dst_get(sk);
 	struct inet_sock *inet = inet_sk(sk);
-	struct net *net = sock_net(sk);
-	struct inet_peer *peer;
-
-	if (!rt ||
-	    inet->cork.fl.u.ip4.daddr != inet->inet_daddr) {
-		peer = inet_getpeer_v4(net, inet->inet_daddr, 1);
-		*release_it = true;
-	} else {
-		peer = rt_get_peer_create(rt, inet->inet_daddr);
-		*release_it = false;
-	}
 
-	return peer;
+	/* If we don't have a valid cached route, or we're doing IP
+	 * options which make the IPv4 header destination address
+	 * different from our peer's, do not bother with this.
+	 */
+	if (!rt || inet->cork.fl.u.ip4.daddr != inet->inet_daddr)
+		return NULL;
+	return rt_get_peer_create(rt, inet->inet_daddr);
 }
 EXPORT_SYMBOL(tcp_v4_get_peer);
 
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index b85d9fe7d663..fef9dbf3af00 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -60,9 +60,8 @@ static bool tcp_remember_stamp(struct sock *sk)
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct inet_peer *peer;
-	bool release_it;
 
-	peer = icsk->icsk_af_ops->get_peer(sk, &release_it);
+	peer = icsk->icsk_af_ops->get_peer(sk);
 	if (peer) {
 		if ((s32)(peer->tcp_ts - tp->rx_opt.ts_recent) <= 0 ||
 		    ((u32)get_seconds() - peer->tcp_ts_stamp > TCP_PAWS_MSL &&
@@ -70,8 +69,6 @@ static bool tcp_remember_stamp(struct sock *sk)
 			peer->tcp_ts_stamp = (u32)tp->rx_opt.ts_recent_stamp;
 			peer->tcp_ts = tp->rx_opt.ts_recent;
 		}
-		if (release_it)
-			inet_putpeer(peer);
 		return true;
 	}
 
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 218433cb9928..b5ecf37b61a6 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1732,23 +1732,18 @@ do_time_wait:
 	goto discard_it;
 }
 
-static struct inet_peer *tcp_v6_get_peer(struct sock *sk, bool *release_it)
+static struct inet_peer *tcp_v6_get_peer(struct sock *sk)
 {
 	struct rt6_info *rt = (struct rt6_info *) __sk_dst_get(sk);
 	struct ipv6_pinfo *np = inet6_sk(sk);
-	struct net *net = sock_net(sk);
-	struct inet_peer *peer;
-
-	if (!rt ||
-	    !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr)) {
-		peer = inet_getpeer_v6(net, &np->daddr, 1);
-		*release_it = true;
-	} else {
-		peer = rt6_get_peer_create(rt);
-		*release_it = false;
-	}
 
-	return peer;
+	/* If we don't have a valid cached route, or we're doing IP
+	 * options which make the IPv6 header destination address
+	 * different from our peer's, do not bother with this.
+	 */
+	if (!rt || !ipv6_addr_equal(&np->daddr, &rt->rt6i_dst.addr))
+		return NULL;
+	return rt6_get_peer_create(rt);
 }
 
 static void *tcp_v6_tw_get_peer(struct sock *sk)