ospfd: Suppress spurious write message when using ip nhrp map multicast

When ip nhrp map multicast is being used, this is usually accompanied by an
iptables rule to block the original multicast packet. This causes sendmsg to
return EPERM.

Signed-off-by: Reuben Dowle <reuben.dowle@4rf.com>

diff --git a/ospfd/ospf_packet.c b/ospfd/ospf_packet.c
index 3f01bf34d3e791af25e645c8418d13a00f463597..aa98d7dd285f51b884bbce74384e3fd05f85630e 100644 (file)
--- a/ospfd/ospf_packet.c
+++ b/ospfd/ospf_packet.c
@@ -799,7 +799,13 @@ static int ospf_write(struct thread *thread)
                                &iph.ip_dst, iph.ip_id, iph.ip_off,
                                iph.ip_len, oi->ifp->name, oi->ifp->mtu);
 
-               if (ret < 0)
+               /* sendmsg will return EPERM if firewall is blocking sending.
+                * This is a normal situation when 'ip nhrp map multicast xxx'
+                * is being used to send multicast packets to DMVPN peers. In
+                * that case the original message is blocked with iptables rule
+                * causing the EPERM result
+                */
+               if (ret < 0 && errno != EPERM)
                        flog_err(
                                EC_LIB_SOCKET,
                                "*** sendmsg in ospf_write failed to %pI4, id %d, off %d, len %d, interface %s, mtu %u: %s",