mptcp: allow to fix the source port when establishing a subflow

By default, when establishing a subflow the source port is selected randomly. This patch allows path managers to specify a source port to use when establishing a subflow by calling __mptcp_init*_subsocket() instead of mptcp_init*_subsocket() (which behavior is unchanged). __mptcp_init*_subsocket() also returns the newly created socket if there were no errors. Signed-off-by: Gregory Detal <gregory.detal@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Christoph Paasch <cpaasch@apple.com>
multipath-tcp · Jan 23, 2019 · 68031f0 · 68031f0
1 parent ed30364
commit 68031f0
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Showing 4 changed files with 36 additions and 12 deletions.
diff --git a/include/net/mptcp_v4.h b/include/net/mptcp_v4.h
@@ -47,14 +47,22 @@ extern struct tcp_request_sock_ops mptcp_join_request_sock_ipv4_ops;
 int mptcp_v4_do_rcv(struct sock *meta_sk, struct sk_buff *skb);
 struct sock *mptcp_v4_search_req(const __be16 rport, const __be32 raddr,
 				 const __be32 laddr, const struct net *net);
-int mptcp_init4_subsockets(struct sock *meta_sk, const struct mptcp_loc4 *loc,
-			   struct mptcp_rem4 *rem);
+int __mptcp_init4_subsockets(struct sock *meta_sk, const struct mptcp_loc4 *loc,
+			     __be16 sport, struct mptcp_rem4 *rem,
+			     struct sock **subsk);
 int mptcp_pm_v4_init(void);
 void mptcp_pm_v4_undo(void);
 u32 mptcp_v4_get_nonce(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport);
 u64 mptcp_v4_get_key(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport,
 		     u32 seed);
 
+static inline int mptcp_init4_subsockets(struct sock *meta_sk,
+					 const struct mptcp_loc4 *loc,
+					 struct mptcp_rem4 *rem)
+{
+	return __mptcp_init4_subsockets(meta_sk, loc, 0, rem, NULL);
+}
+
 #else
 
 static inline int mptcp_v4_do_rcv(const struct sock *meta_sk,

diff --git a/include/net/mptcp_v6.h b/include/net/mptcp_v6.h
@@ -46,15 +46,23 @@ extern struct tcp_request_sock_ops mptcp_join_request_sock_ipv6_ops;
 int mptcp_v6_do_rcv(struct sock *meta_sk, struct sk_buff *skb);
 struct sock *mptcp_v6_search_req(const __be16 rport, const struct in6_addr *raddr,
 				 const struct in6_addr *laddr, const struct net *net);
-int mptcp_init6_subsockets(struct sock *meta_sk, const struct mptcp_loc6 *loc,
-			   struct mptcp_rem6 *rem);
+int __mptcp_init6_subsockets(struct sock *meta_sk, const struct mptcp_loc6 *loc,
+			     __be16 sport, struct mptcp_rem6 *rem,
+			     struct sock **subsk);
 int mptcp_pm_v6_init(void);
 void mptcp_pm_v6_undo(void);
 __u32 mptcp_v6_get_nonce(const __be32 *saddr, const __be32 *daddr,
 			 __be16 sport, __be16 dport);
 u64 mptcp_v6_get_key(const __be32 *saddr, const __be32 *daddr,
 		     __be16 sport, __be16 dport, u32 seed);
 
+static inline int mptcp_init6_subsockets(struct sock *meta_sk,
+					 const struct mptcp_loc6 *loc,
+					 struct mptcp_rem6 *rem)
+{
+	return __mptcp_init6_subsockets(meta_sk, loc, 0, rem, NULL);
+}
+
 #else /* CONFIG_MPTCP */
 
 #define mptcp_v6_mapped ipv6_mapped

diff --git a/net/mptcp/mptcp_ipv4.c b/net/mptcp/mptcp_ipv4.c
@@ -254,8 +254,9 @@ int mptcp_v4_do_rcv(struct sock *meta_sk, struct sk_buff *skb)
  *
  * We are in user-context and meta-sock-lock is hold.
  */
-int mptcp_init4_subsockets(struct sock *meta_sk, const struct mptcp_loc4 *loc,
-			   struct mptcp_rem4 *rem)
+int __mptcp_init4_subsockets(struct sock *meta_sk, const struct mptcp_loc4 *loc,
+			     __be16 sport, struct mptcp_rem4 *rem,
+			     struct sock **subsk)
 {
 	struct tcp_sock *tp;
 	struct sock *sk;
@@ -299,7 +300,7 @@ int mptcp_init4_subsockets(struct sock *meta_sk, const struct mptcp_loc4 *loc,
 	/** Then, connect the socket to the peer */
 	loc_in.sin_family = AF_INET;
 	rem_in.sin_family = AF_INET;
-	loc_in.sin_port = 0;
+	loc_in.sin_port = sport;
 	if (rem->port)
 		rem_in.sin_port = rem->port;
 	else
@@ -341,6 +342,9 @@ int mptcp_init4_subsockets(struct sock *meta_sk, const struct mptcp_loc4 *loc,
 	sk_set_socket(sk, meta_sk->sk_socket);
 	sk->sk_wq = meta_sk->sk_wq;
 
+	if (subsk)
+		*subsk = sk;
+
 	return 0;
 
 error:
@@ -354,7 +358,7 @@ int mptcp_init4_subsockets(struct sock *meta_sk, const struct mptcp_loc4 *loc,
 	}
 	return ret;
 }
-EXPORT_SYMBOL(mptcp_init4_subsockets);
+EXPORT_SYMBOL(__mptcp_init4_subsockets);
 
 const struct inet_connection_sock_af_ops mptcp_v4_specific = {
 	.queue_xmit	   = ip_queue_xmit,

diff --git a/net/mptcp/mptcp_ipv6.c b/net/mptcp/mptcp_ipv6.c
@@ -282,8 +282,9 @@ int mptcp_v6_do_rcv(struct sock *meta_sk, struct sk_buff *skb)
  *
  * We are in user-context and meta-sock-lock is hold.
  */
-int mptcp_init6_subsockets(struct sock *meta_sk, const struct mptcp_loc6 *loc,
-			   struct mptcp_rem6 *rem)
+int __mptcp_init6_subsockets(struct sock *meta_sk, const struct mptcp_loc6 *loc,
+			     __be16 sport, struct mptcp_rem6 *rem,
+			     struct sock **subsk)
 {
 	struct tcp_sock *tp;
 	struct sock *sk;
@@ -327,7 +328,7 @@ int mptcp_init6_subsockets(struct sock *meta_sk, const struct mptcp_loc6 *loc,
 	/** Then, connect the socket to the peer */
 	loc_in.sin6_family = AF_INET6;
 	rem_in.sin6_family = AF_INET6;
-	loc_in.sin6_port = 0;
+	loc_in.sin6_port = sport;
 	if (rem->port)
 		rem_in.sin6_port = rem->port;
 	else
@@ -369,6 +370,9 @@ int mptcp_init6_subsockets(struct sock *meta_sk, const struct mptcp_loc6 *loc,
 	sk_set_socket(sk, meta_sk->sk_socket);
 	sk->sk_wq = meta_sk->sk_wq;
 
+	if (subsk)
+		*subsk = sk;
+
 	return 0;
 
 error:
@@ -382,7 +386,7 @@ int mptcp_init6_subsockets(struct sock *meta_sk, const struct mptcp_loc6 *loc,
 	}
 	return ret;
 }
-EXPORT_SYMBOL(mptcp_init6_subsockets);
+EXPORT_SYMBOL(__mptcp_init6_subsockets);
 
 const struct inet_connection_sock_af_ops mptcp_v6_specific = {
 	.queue_xmit	   = inet6_csk_xmit,