tipc: clean up connection protocol reception function

[firefly-linux-kernel-4.4.55.git] / net / tipc / socket.c

diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index d838a4b66d3aed2eb2ef503405b4a20cd2809d42..1762323156af262cb9cfdbd10d7c33fe51249288 100644 (file)
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -46,6 +46,7 @@
 #define SS_READY       -2      /* socket is connectionless */
 
 #define CONN_TIMEOUT_DEFAULT   8000    /* default connect timeout = 8s */
+#define TIPC_FWD_MSG           1
 
 static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 static void tipc_data_ready(struct sock *sk);
@@ -533,6 +534,46 @@ static unsigned int tipc_poll(struct file *file, struct socket *sock,
        return mask;
 }
 
+/**
+ * tipc_sk_proto_rcv - receive a connection mng protocol message
+ * @tsk: receiving socket
+ * @dnode: node to send response message to, if any
+ * @buf: buffer containing protocol message
+ * Returns 0 (TIPC_OK) if message was consumed, 1 (TIPC_FWD_MSG) if
+ * (CONN_PROBE_REPLY) message should be forwarded.
+ */
+int tipc_sk_proto_rcv(struct tipc_sock *tsk, u32 *dnode, struct sk_buff *buf)
+{
+       struct tipc_msg *msg = buf_msg(buf);
+       struct tipc_port *port = &tsk->port;
+       int wakeable;
+
+       /* Ignore if connection cannot be validated: */
+       if (!port->connected || !tipc_port_peer_msg(port, msg))
+               goto exit;
+
+       port->probing_state = TIPC_CONN_OK;
+
+       if (msg_type(msg) == CONN_ACK) {
+               wakeable = tipc_port_congested(port) && port->congested;
+               port->acked += msg_msgcnt(msg);
+               if (!tipc_port_congested(port)) {
+                       port->congested = 0;
+                       if (wakeable)
+                               tipc_port_wakeup(port);
+               }
+       } else if (msg_type(msg) == CONN_PROBE) {
+               if (!tipc_msg_reverse(buf, dnode, TIPC_OK))
+                       return TIPC_OK;
+               msg_set_type(msg, CONN_PROBE_REPLY);
+               return TIPC_FWD_MSG;
+       }
+       /* Do nothing if msg_type() == CONN_PROBE_REPLY */
+exit:
+       kfree_skb(buf);
+       return TIPC_OK;
+}
+
 /**
  * dest_name_check - verify user is permitted to send to specified port name
  * @dest: destination address
@@ -1406,7 +1447,7 @@ static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *buf)
  * Called with socket lock already taken; port lock may also be taken.
  *
  * Returns 0 (TIPC_OK) if message was consumed, -TIPC error code if message
- * to be rejected.
+ * to be rejected, 1 (TIPC_FWD_MSG) if (CONN_MANAGER) message to be forwarded
  */
 static int filter_rcv(struct sock *sk, struct sk_buff *buf)
 {
@@ -1414,12 +1455,11 @@ static int filter_rcv(struct sock *sk, struct sk_buff *buf)
        struct tipc_sock *tsk = tipc_sk(sk);
        struct tipc_msg *msg = buf_msg(buf);
        unsigned int limit = rcvbuf_limit(sk, buf);
+       u32 onode;
        int rc = TIPC_OK;
 
-       if (unlikely(msg_user(msg) == CONN_MANAGER)) {
-               tipc_port_proto_rcv(&tsk->port, buf);
-               return TIPC_OK;
-       }
+       if (unlikely(msg_user(msg) == CONN_MANAGER))
+               return tipc_sk_proto_rcv(tsk, &onode, buf);
 
        /* Reject message if it is wrong sort of message for socket */
        if (msg_type(msg) > TIPC_DIRECT_MSG)
@@ -1465,10 +1505,16 @@ static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *buf)
 
        rc = filter_rcv(sk, buf);
 
-       if (unlikely(rc && tipc_msg_reverse(buf, &onode, -rc)))
-               tipc_link_xmit2(buf, onode, 0);
-       else if (atomic_read(&tsk->dupl_rcvcnt) < TIPC_CONN_OVERLOAD_LIMIT)
-               atomic_add(truesize, &tsk->dupl_rcvcnt);
+       if (likely(!rc)) {
+               if (atomic_read(&tsk->dupl_rcvcnt) < TIPC_CONN_OVERLOAD_LIMIT)
+                       atomic_add(truesize, &tsk->dupl_rcvcnt);
+               return 0;
+       }
+
+       if ((rc < 0) && !tipc_msg_reverse(buf, &onode, -rc))
+               return 0;
+
+       tipc_link_xmit2(buf, onode, 0);
 
        return 0;
 }