In ip_output(), initialise `ia' in the case where the packet has

come from a dummynet pipe. Without this, the code which increments
the per-ifaddr stats can dereference an uninitialised pointer. This
should make dummynet usable again.

Reported by:	"Dmitry A. Yanko" <fm@astral.ntu-kpi.kiev.ua>
Reviewed by:	luigi, joe

sys/netinet/ip_output.c

@@ -180,6 +180,7 @@ ip_output(m0, opt, ro, flags, imo)
 #endif
             ip = mtod(m, struct ip *);
             hlen = IP_VHL_HL(ip->ip_vhl) << 2 ;
+            ia = (struct in_ifaddr *)ro->ro_rt->rt_ifa;
             goto sendit;
         } else
             rule = NULL ;