tipc: failed transmissions should return error

When a message could not be sent out because the destination node
or link could not be found, the full message size is returned from
sendmsg() as if it had been sent successfully. An application will
then get a false indication that it's making forward progress. This
problem has existed since the initial commit in 2.6.16.

We change this to return -ENETUNREACH if the message cannot be
delivered due to the destination node/link being unavailable. We
also get rid of the redundant tipc_reject_msg call since freeing
the buffer and doing a tipc_port_iovec_reject accomplishes exactly
the same thing.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 284d6383ad6ccca32ee60eb04fcc15d3a745b90e..d1a764b9b2d81a2374e8a01235e345adb0f18c48 100644 (file)
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1020,12 +1020,9 @@ exit:
        read_unlock_bh(&tipc_net_lock);
 
        /* Couldn't find a link to the destination node */
-       if (buf)
-               return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
-       if (res >= 0)
-               return tipc_port_iovec_reject(sender, hdr, msg_sect, len,
-                                             TIPC_ERR_NO_NODE);
-       return res;
+       kfree_skb(buf);
+       tipc_port_iovec_reject(sender, hdr, msg_sect, len, TIPC_ERR_NO_NODE);
+       return -ENETUNREACH;
 }
 
 /*
@@ -1163,8 +1160,9 @@ error:
        } else {
 reject:
                kfree_skb_list(buf_chain);
-               return tipc_port_iovec_reject(sender, hdr, msg_sect,
-                                             len, TIPC_ERR_NO_NODE);
+               tipc_port_iovec_reject(sender, hdr, msg_sect, len,
+                                      TIPC_ERR_NO_NODE);
+               return -ENETUNREACH;
        }
 
        /* Append chain of fragments to send queue & send them */