tipc: fix wrong return value from function tipc_node_try_addr()

[ Upstream commit 2a57f182420174c7fd4b19db979a2d135231a963 ]

The function for checking if there is an node address conflict is
supposed to return a suggestion for a new address if it finds a
conflict, and zero otherwise. But in case the peer being checked
is previously unknown it does instead return a "suggestion" for
the checked address itself. This results in a DSC_TRIAL_FAIL_MSG
being sent unecessarily to the peer, and sometimes makes the trial
period starting over again.

Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/tipc/node.c b/net/tipc/node.c
index f29549de9245f63229241cd63f798a114182b0f5..aa09c515775ff0e60e7ae38ab4caf51321c88b57 100644 (file)
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -776,6 +776,7 @@ static u32 tipc_node_suggest_addr(struct net *net, u32 addr)
 }
 
 /* tipc_node_try_addr(): Check if addr can be used by peer, suggest other if not
+ * Returns suggested address if any, otherwise 0
  */
 u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
 {
@@ -798,12 +799,14 @@ u32 tipc_node_try_addr(struct net *net, u8 *id, u32 addr)
        if (n) {
                addr = n->addr;
                tipc_node_put(n);
+               return addr;
        }
-       /* Even this node may be in trial phase */
+
+       /* Even this node may be in conflict */
        if (tn->trial_addr == addr)
                return tipc_node_suggest_addr(net, addr);
 
-       return addr;
+       return 0;
 }
 
 void tipc_node_check_dest(struct net *net, u32 addr,