From 50706577a436f552d3b0cbb86d7664db6d9231f5 Mon Sep 17 00:00:00 2001
From: kmacy <kmacy@FreeBSD.org>
Date: Wed, 12 Dec 2007 20:53:25 +0000
Subject: [PATCH] add interface for allowing consumers to register for ARP
 updates, redirects, and path MTU changes

Reviewed by: silby
---
 sys/net/route.c        | 17 +++++++++++++----
 sys/net/route.h        |  7 +++++++
 sys/netinet/if_ether.c |  9 ++++++++-
 3 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/sys/net/route.c b/sys/net/route.c
index 8ea21324621c..543383a50164 100644
--- a/sys/net/route.c
+++ b/sys/net/route.c
@@ -318,7 +318,7 @@ rtredirect(struct sockaddr *dst,
 	int flags,
 	struct sockaddr *src)
 {
-	struct rtentry *rt;
+	struct rtentry *rt, *rt0 = NULL;
 	int error = 0;
 	short *stat = NULL;
 	struct rt_addrinfo info;
@@ -362,8 +362,9 @@ rtredirect(struct sockaddr *dst,
 			 * Create new route, rather than smashing route to net.
 			 */
 		create:
-			if (rt)
-				rtfree(rt);
+			rt0 = rt;
+			rt = NULL;
+		
 			flags |=  RTF_GATEWAY | RTF_DYNAMIC;
 			bzero((caddr_t)&info, sizeof(info));
 			info.rti_info[RTAX_DST] = dst;
@@ -371,14 +372,19 @@ rtredirect(struct sockaddr *dst,
 			info.rti_info[RTAX_NETMASK] = netmask;
 			info.rti_ifa = ifa;
 			info.rti_flags = flags;
-			rt = NULL;
 			error = rtrequest1(RTM_ADD, &info, &rt);
 			if (rt != NULL) {
 				RT_LOCK(rt);
+				EVENTHANDLER_INVOKE(route_event, RTEVENT_REDIRECT_UPDATE, rt0, rt, dst);
 				flags = rt->rt_flags;
 			}
+			if (rt0)
+				RTFREE_LOCKED(rt0);
+			
 			stat = &rtstat.rts_dynamic;
 		} else {
+			struct rtentry *gwrt;
+
 			/*
 			 * Smash the current notion of the gateway to
 			 * this destination.  Should check about netmask!!!
@@ -390,6 +396,9 @@ rtredirect(struct sockaddr *dst,
 			 * add the key and gateway (in one malloc'd chunk).
 			 */
 			rt_setgate(rt, rt_key(rt), gateway);
+			gwrt = rtalloc1(gateway, 1, 0);
+			EVENTHANDLER_INVOKE(route_event, RTEVENT_REDIRECT_UPDATE, rt, gwrt, dst);
+			RTFREE_LOCKED(gwrt);
 		}
 	} else
 		error = EHOSTUNREACH;
diff --git a/sys/net/route.h b/sys/net/route.h
index b40821394f31..423cccbb8a50 100644
--- a/sys/net/route.h
+++ b/sys/net/route.h
@@ -359,6 +359,13 @@ int	 rtrequest(int, struct sockaddr *,
 	    struct sockaddr *, struct sockaddr *, int, struct rtentry **);
 int	 rtrequest1(int, struct rt_addrinfo *, struct rtentry **);
 int	 rt_check(struct rtentry **, struct rtentry **, struct sockaddr *);
+
+#include <sys/eventhandler.h>
+#define RTEVENT_ARP_UPDATE        1
+#define RTEVENT_PMTU_UPDATE       2
+#define RTEVENT_REDIRECT_UPDATE   3
+typedef void (*rtevent_fn)(void *, int, struct rtentry *, struct rtentry *, struct sockaddr *);
+EVENTHANDLER_DECLARE(route_event, rtevent_fn);
 #endif
 
 #endif
diff --git a/sys/netinet/if_ether.c b/sys/netinet/if_ether.c
index 98f26df4c3f8..33e77040968c 100644
--- a/sys/netinet/if_ether.c
+++ b/sys/netinet/if_ether.c
@@ -578,7 +578,10 @@ in_arpinput(struct mbuf *m)
 #ifdef DEV_CARP
 	int carp_match = 0;
 #endif
-
+	struct sockaddr_in sin;
+	sin.sin_len = sizeof(struct sockaddr_in);
+	sin.sin_family = AF_INET;
+	
 	if (ifp->if_bridge)
 		bridged = 1;
 
@@ -772,6 +775,10 @@ match:
 	la->la_preempt = arp_maxtries;
 	hold = la->la_hold;
 	la->la_hold = NULL;
+
+	sin.sin_addr.s_addr = ntohl(itaddr.s_addr);
+	EVENTHANDLER_INVOKE(route_event, RTEVENT_ARP_UPDATE, rt, NULL,
+	    (struct sockaddr *)&sin);
 	RT_UNLOCK(rt);
 	if (hold != NULL)
 		(*ifp->if_output)(ifp, hold, rt_key(rt), rt);