tipc: Ensure network address change doesn't impact local connections

Revises routines that deal with connections between two ports on
the same node to ensure the connection is not impacted if the node's
network address is changed in mid-operation. The routines now treat
the default node address of <0.0.0> as an alias for "this node" in
the following situations:

1) Incoming messages destined to a connected port now handle the alias
properly when validating that the message was sent by the expected
peer port, ensuring that the message will be accepted regardless of
whether it specifies the node's old network address or it's current one.

2) The code which completes connection establishment now handles the
alias properly when determining if the peer port is on the same node
as the connected port.

An added benefit of addressing issue 1) is that some peer port
validation code has been relocated to TIPC's socket subsystem, which
means that validation is no longer done twice when a message is
sent to a non-socket port (such as TIPC's configuration service or
network topology service).

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

1 files changed, 30 insertions, 29 deletions

diff --git a/net/tipc/port.c b/net/tipc/port.c
index f1f6b33f761..616c72fb923 100644
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -69,6 +69,28 @@ static inline u32 port_peerport(struct tipc_port *p_ptr)
 	return msg_destport(&p_ptr->phdr);
 }
 
+/*
+ * tipc_port_peer_msg - verify message was sent by connected port's peer
+ *
+ * Handles cases where the node's network address has changed from
+ * the default of <0.0.0> to its configured setting.
+ */
+
+int tipc_port_peer_msg(struct tipc_port *p_ptr, struct tipc_msg *msg)
+{
+	u32 peernode;
+	u32 orignode;
+
+	if (msg_origport(msg) != port_peerport(p_ptr))
+		return 0;
+
+	orignode = msg_orignode(msg);
+	peernode = port_peernode(p_ptr);
+	return (orignode == peernode) ||
+		(!orignode && (peernode == tipc_own_addr)) ||
+		(!peernode && (orignode == tipc_own_addr));
+}
+
 /**
  * tipc_multicast - send a multicast message to local and remote destinations
  */
@@ -526,25 +548,21 @@ void tipc_port_recv_proto_msg(struct sk_buff *buf)
 	struct tipc_msg *msg = buf_msg(buf);
 	struct tipc_port *p_ptr;
 	struct sk_buff *r_buf = NULL;
-	u32 orignode = msg_orignode(msg);
-	u32 origport = msg_origport(msg);
 	u32 destport = msg_destport(msg);
 	int wakeable;
 
 	/* Validate connection */
 
 	p_ptr = tipc_port_lock(destport);
-	if (!p_ptr || !p_ptr->connected ||
-	    (port_peernode(p_ptr) != orignode) ||
-	    (port_peerport(p_ptr) != origport)) {
+	if (!p_ptr || !p_ptr->connected || !tipc_port_peer_msg(p_ptr, msg)) {
 		r_buf = tipc_buf_acquire(BASIC_H_SIZE);
 		if (r_buf) {
 			msg = buf_msg(r_buf);
 			tipc_msg_init(msg, TIPC_HIGH_IMPORTANCE, TIPC_CONN_MSG,
-				      BASIC_H_SIZE, orignode);
+				      BASIC_H_SIZE, msg_orignode(msg));
 			msg_set_errcode(msg, TIPC_ERR_NO_PORT);
 			msg_set_origport(msg, destport);
-			msg_set_destport(msg, origport);
+			msg_set_destport(msg, msg_origport(msg));
 		}
 		if (p_ptr)
 			tipc_port_unlock(p_ptr);
@@ -681,6 +699,7 @@ static void port_dispatcher_sigh(void *dummy)
 		struct tipc_name_seq dseq;
 		void *usr_handle;
 		int connected;
+		int peer_invalid;
 		int published;
 		u32 message_type;
 
@@ -701,6 +720,7 @@ static void port_dispatcher_sigh(void *dummy)
 		up_ptr = p_ptr->user_port;
 		usr_handle = up_ptr->usr_handle;
 		connected = p_ptr->connected;
+		peer_invalid = connected && !tipc_port_peer_msg(p_ptr, msg);
 		published = p_ptr->published;
 
 		if (unlikely(msg_errcode(msg)))
@@ -710,8 +730,6 @@ static void port_dispatcher_sigh(void *dummy)
 
 		case TIPC_CONN_MSG:{
 				tipc_conn_msg_event cb = up_ptr->conn_msg_cb;
-				u32 peer_port = port_peerport(p_ptr);
-				u32 peer_node = port_peernode(p_ptr);
 				u32 dsz;
 
 				tipc_port_unlock(p_ptr);
@@ -720,8 +738,7 @@ static void port_dispatcher_sigh(void *dummy)
 				if (unlikely(!connected)) {
 					if (tipc_connect2port(dref, &orig))
 						goto reject;
-				} else if ((msg_origport(msg) != peer_port) ||
-					   (msg_orignode(msg) != peer_node))
+				} else if (peer_invalid)
 					goto reject;
 				dsz = msg_data_sz(msg);
 				if (unlikely(dsz &&
@@ -773,14 +790,9 @@ err:
 		case TIPC_CONN_MSG:{
 				tipc_conn_shutdown_event cb =
 					up_ptr->conn_err_cb;
-				u32 peer_port = port_peerport(p_ptr);
-				u32 peer_node = port_peernode(p_ptr);
 
 				tipc_port_unlock(p_ptr);
-				if (!cb || !connected)
-					break;
-				if ((msg_origport(msg) != peer_port) ||
-				    (msg_orignode(msg) != peer_node))
+				if (!cb || !connected || peer_invalid)
 					break;
 				tipc_disconnect(dref);
 				skb_pull(buf, msg_hdr_sz(msg));
@@ -1157,17 +1169,6 @@ int tipc_port_recv_msg(struct sk_buff *buf)
 	/* validate destination & pass to port, otherwise reject message */
 	p_ptr = tipc_port_lock(destport);
 	if (likely(p_ptr)) {
-		if (likely(p_ptr->connected)) {
-			if ((unlikely(msg_origport(msg) !=
-				      port_peerport(p_ptr))) ||
-			    (unlikely(msg_orignode(msg) !=
-				      port_peernode(p_ptr))) ||
-			    (unlikely(!msg_connected(msg)))) {
-				err = TIPC_ERR_NO_PORT;
-				tipc_port_unlock(p_ptr);
-				goto reject;
-			}
-		}
 		err = p_ptr->dispatcher(p_ptr, buf);
 		tipc_port_unlock(p_ptr);
 		if (likely(!err))
@@ -1175,7 +1176,7 @@ int tipc_port_recv_msg(struct sk_buff *buf)
 	} else {
 		err = TIPC_ERR_NO_PORT;
 	}
-reject:
+
 	return tipc_reject_msg(buf, err);
 }