tipc: fix link attribute propagation bug

Changing certain link attributes (link tolerance and link priority)
from the TIPC management tool is supposed to automatically take
effect at both endpoints of the affected link.

Currently the media address is not instantiated for the link and is
used uninstantiated when crafting protocol messages designated for the
peer endpoint. This means that changing a link property currently
results in the property being changed on the local machine but the
protocol message designated for the peer gets lost. Resulting in
property discrepancy between the endpoints.

In this patch we resolve this by using the media address from the
link entry and using the bearer transmit function to send it. Hence,
we can now eliminate the redundant function tipc_link_prot_xmit() and
the redundant field tipc_link::media_addr.

Fixes: 2af5ae372a4b (tipc: clean up unused code and structures)
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reported-by: Jason Hu <huzhijiang@gmail.com>
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 3 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index fa97d9649a28..f8a8255a7182 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -1637,9 +1637,12 @@ int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
         char *name;
         struct tipc_link *link;
         struct tipc_node *node;
+        struct sk_buff_head xmitq;
         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
         struct net *net = sock_net(skb->sk);
 
+        __skb_queue_head_init(&xmitq);
+
         if (!info->attrs[TIPC_NLA_LINK])
                 return -EINVAL;
 
@@ -1683,13 +1686,13 @@ int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
                         u32 tol;
 
                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
-                        tipc_link_set_tolerance(link, tol);
+                        tipc_link_set_tolerance(link, tol, &xmitq);
                 }
                 if (props[TIPC_NLA_PROP_PRIO]) {
                         u32 prio;
 
                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
-                        tipc_link_set_prio(link, prio);
+                        tipc_link_set_prio(link, prio, &xmitq);
                 }
                 if (props[TIPC_NLA_PROP_WIN]) {
                         u32 win;
@@ -1701,7 +1704,7 @@ int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
 
 out:
         tipc_node_read_unlock(node);
-
+        tipc_bearer_xmit(net, bearer_id, &xmitq, &node->links[bearer_id].maddr);
         return res;
 }