The proxy arp entries could not be added into the system over the

IFF_POINTOPOINT link types. The reason was due to the routing
entry returned from the kernel covering the remote end is of an
interface type that does not support ARP. This patch fixes this
problem by providing a hint to the kernel routing code, which
indicates the prefix route instead of the PPP host route should
be returned to the caller. Since a host route to the local end
point is also added into the routing table, and there could be
multiple such instantiations due to multiple PPP links can be
created with the same local end IP address, this patch also fixes
the loopback route installation failure problem observed prior to
this patch. The reference count of loopback route to local end would
be either incremented or decremented. The first instantiation would
create the entry and the last removal would delete the route entry.

MFC after:	5 days

1 files changed, 22 insertions, 0 deletions

diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index a0677ec..df4f9ae 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -60,6 +60,7 @@
 #include <net/vnet.h>
 
 #include <netinet/in.h>
+#include <netinet/if_ether.h>
 #ifdef INET6
 #include <netinet6/scope6_var.h>
 #endif
@@ -622,6 +623,27 @@ route_output(struct mbuf *m, struct socket *so)
 			}
 		}
 #endif
+		/*
+		 * If performing proxied L2 entry insertion, and
+		 * the actual PPP host entry is found, perform
+		 * another search to retrieve the prefix route of
+		 * the local end point of the PPP link.
+		 */
+		if ((rtm->rtm_flags & RTF_ANNOUNCE) &&
+		    (rt->rt_ifp->if_flags & IFF_POINTOPOINT)) {
+			struct sockaddr laddr;
+			rt_maskedcopy(rt->rt_ifa->ifa_addr,
+				      &laddr,
+				      rt->rt_ifa->ifa_netmask);
+			/* 
+			 * refactor rt and no lock operation necessary
+			 */
+			rt = (struct rtentry *)rnh->rnh_matchaddr(&laddr, rnh);
+			if (rt == NULL) {
+				RADIX_NODE_HEAD_RUNLOCK(rnh);
+				senderr(ESRCH);
+			}
+		} 
 		RT_LOCK(rt);
 		RT_ADDREF(rt);
 		RADIX_NODE_HEAD_RUNLOCK(rnh);