1 files changed, 56 insertions, 32 deletions

diff --git a/include/net/route.h b/include/net/route.h
index 3684c3edbae4..79530da31b34 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -217,17 +217,37 @@ static inline char rt_tos2priority(u8 tos)
 	return ip_tos2prio[IPTOS_TOS(tos)>>1];
 }
 
-static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos,
-					      int oif, u8 protocol,
-					      __be16 sport, __be16 dport,
-					      struct sock *sk, bool can_sleep)
+/* ip_route_connect() and ip_route_newports() work in tandem whilst
+ * binding a socket for a new outgoing connection.
+ *
+ * In order to use IPSEC properly, we must, in the end, have a
+ * route that was looked up using all available keys including source
+ * and destination ports.
+ *
+ * However, if a source port needs to be allocated (the user specified
+ * a wildcard source port) we need to obtain addressing information
+ * in order to perform that allocation.
+ *
+ * So ip_route_connect() looks up a route using wildcarded source and
+ * destination ports in the key, simply so that we can get a pair of
+ * addresses to use for port allocation.
+ *
+ * Later, once the ports are allocated, ip_route_newports() will make
+ * another route lookup if needed to make sure we catch any IPSEC
+ * rules keyed on the port information.
+ *
+ * The callers allocate the flow key on their stack, and must pass in
+ * the same flowi4 object to both the ip_route_connect() and the
+ * ip_route_newports() calls.
+ */
+
+static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32 src,
+					 u32 tos, int oif, u8 protocol,
+					 __be16 sport, __be16 dport,
+					 struct sock *sk, bool can_sleep)
 {
-	struct net *net = sock_net(sk);
-	struct rtable *rt;
-	struct flowi4 fl4;
-	__u8 flow_flags;
+	__u8 flow_flags = 0;
 
-	flow_flags = 0;
 	if (inet_sk(sk)->transparent)
 		flow_flags |= FLOWI_FLAG_ANYSRC;
 	if (protocol == IPPROTO_TCP)
@@ -235,41 +255,45 @@ static inline struct rtable *ip_route_connect(__be32 dst, __be32 src, u32 tos,
 	if (can_sleep)
 		flow_flags |= FLOWI_FLAG_CAN_SLEEP;
 
-	flowi4_init_output(&fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
+	flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
 			   protocol, flow_flags, dst, src, dport, sport);
+}
+
+static inline struct rtable *ip_route_connect(struct flowi4 *fl4,
+					      __be32 dst, __be32 src, u32 tos,
+					      int oif, u8 protocol,
+					      __be16 sport, __be16 dport,
+					      struct sock *sk, bool can_sleep)
+{
+	struct net *net = sock_net(sk);
+	struct rtable *rt;
+
+	ip_route_connect_init(fl4, dst, src, tos, oif, protocol,
+			      sport, dport, sk, can_sleep);
 
 	if (!dst || !src) {
-		rt = __ip_route_output_key(net, &fl4);
+		rt = __ip_route_output_key(net, fl4);
 		if (IS_ERR(rt))
 			return rt;
-		fl4.daddr = rt->rt_dst;
-		fl4.saddr = rt->rt_src;
+		fl4->daddr = rt->rt_dst;
+		fl4->saddr = rt->rt_src;
 		ip_rt_put(rt);
 	}
-	security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
-	return ip_route_output_flow(net, &fl4, sk);
+	security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
+	return ip_route_output_flow(net, fl4, sk);
 }
 
-static inline struct rtable *ip_route_newports(struct rtable *rt,
-					       u8 protocol, __be16 orig_sport,
-					       __be16 orig_dport, __be16 sport,
-					       __be16 dport, struct sock *sk)
+static inline struct rtable *ip_route_newports(struct flowi4 *fl4, struct rtable *rt,
+					       __be16 orig_sport, __be16 orig_dport,
+					       __be16 sport, __be16 dport,
+					       struct sock *sk)
 {
 	if (sport != orig_sport || dport != orig_dport) {
-		struct flowi4 fl4;
-		__u8 flow_flags;
-
-		flow_flags = 0;
-		if (inet_sk(sk)->transparent)
-			flow_flags |= FLOWI_FLAG_ANYSRC;
-		if (protocol == IPPROTO_TCP)
-			flow_flags |= FLOWI_FLAG_PRECOW_METRICS;
-		flowi4_init_output(&fl4, rt->rt_oif, rt->rt_mark, rt->rt_tos,
-				   RT_SCOPE_UNIVERSE, protocol, flow_flags,
-				   rt->rt_dst, rt->rt_src, dport, sport);
+		fl4->fl4_dport = dport;
+		fl4->fl4_sport = sport;
 		ip_rt_put(rt);
-		security_sk_classify_flow(sk, flowi4_to_flowi(&fl4));
-		return ip_route_output_flow(sock_net(sk), &fl4, sk);
+		security_sk_classify_flow(sk, flowi4_to_flowi(fl4));
+		return ip_route_output_flow(sock_net(sk), fl4, sk);
 	}
 	return rt;
 }