linux-cp: Fix looping netlink messages

Signal when consuming a batch of netlink messages, in order to inhibit
lcp_sync from generating new netlink messages. This avoids link up/down
state changess from triggering an infinite loop.
Do this in the regular case of nl_route_process_msgs()
and in the special case of re-synchronizing in lcp_nl_recv_dump_replies().
Type: fix
Change-Id: I419d3f9aa350c119b3778b644c65165cb4cc1bef
Signed-off-by: Pim van Pelt <pim@ipng.nl>

1 files changed, 12 insertions, 1 deletions

diff --git a/src/plugins/linux-cp/lcp_nl.c b/src/plugins/linux-cp/lcp_nl.c
index b548d7afa39..85b6447007a 100644
--- a/src/plugins/linux-cp/lcp_nl.c
+++ b/src/plugins/linux-cp/lcp_nl.c
@@ -348,6 +348,8 @@ nl_route_process_msgs (void)
   nl_msg_info_t *msg_info;
   int err, n_msgs = 0;
 
+  lcp_set_netlink_processing_active (1);
+
   /* process a batch of messages. break if we hit our limit */
   vec_foreach (msg_info, nm->nl_msg_queue)
     {
@@ -365,6 +367,8 @@ nl_route_process_msgs (void)
 
   NL_DBG ("Processed %u messages", n_msgs);
 
+  lcp_set_netlink_processing_active (0);
+
   return n_msgs;
 }
 
@@ -441,10 +445,15 @@ lcp_nl_recv_dump_replies (nl_sock_type_t sock_type, int msg_limit,
   int done = 0;
   int n_msgs = 0;
 
+  lcp_set_netlink_processing_active (1);
+
 continue_reading:
   n_bytes = nl_recv (sk_route, &nla, &buf, /* creds */ NULL);
   if (n_bytes <= 0)
-    return n_bytes;
+    {
+      lcp_set_netlink_processing_active (0);
+      return n_bytes;
+    }
 
   hdr = (struct nlmsghdr *) buf;
   while (nlmsg_ok (hdr, n_bytes))
@@ -521,6 +530,8 @@ continue_reading:
     goto continue_reading;
 
 out:
+  lcp_set_netlink_processing_active (0);
+
   nlmsg_free (msg);
   free (buf);