Add CARP (Common Address Redundancy Protocol), which allows multiple

hosts to share an IP address, providing high availability and load
balancing.

Original work on CARP done by Michael Shalayeff, with many
additions by Marco Pfatschbacher and Ryan McBride.

FreeBSD port done solely by Max Laier.

Patch by:	mlaier
Obtained from:	OpenBSD (mickey, mcbride)

1 files changed, 18 insertions, 0 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index b6505df..3c25986 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -34,6 +34,7 @@
 #include "opt_inet6.h"
 #include "opt_inet.h"
 #include "opt_mac.h"
+#include "opt_carp.h"
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -78,6 +79,9 @@
 #ifdef INET
 #include <netinet/if_ether.h>
 #endif
+#ifdef DEV_CARP
+#include <netinet/ip_carp.h>
+#endif
 
 void	(*ng_ether_link_state_p)(struct ifnet *ifp, int state);
 
@@ -529,6 +533,12 @@ if_detach(struct ifnet *ifp)
  	int found;
 
 	EVENTHANDLER_INVOKE(ifnet_departure_event, ifp);
+#ifdef DEV_CARP
+	/* Maybe hook to the generalized departure handler above?!? */
+	if (ifp->if_carp)
+		carp_ifdetach(ifp);
+#endif
+
 	/*
 	 * Remove routes and flush queues.
 	 */
@@ -933,6 +943,10 @@ if_unroute(struct ifnet *ifp, int flag, int fam)
 		if (fam == PF_UNSPEC || (fam == ifa->ifa_addr->sa_family))
 			pfctlinput(PRC_IFDOWN, ifa->ifa_addr);
 	if_qflush(&ifp->if_snd);
+#ifdef DEV_CARP
+	if (ifp->if_carp)
+		carp_carpdev_state(ifp->if_carp);
+#endif
 	rt_ifmsg(ifp);
 }
 
@@ -951,6 +965,10 @@ if_route(struct ifnet *ifp, int flag, int fam)
 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
 		if (fam == PF_UNSPEC || (fam == ifa->ifa_addr->sa_family))
 			pfctlinput(PRC_IFUP, ifa->ifa_addr);
+#ifdef DEV_CARP
+	if (ifp->if_carp)
+		carp_carpdev_state(ifp->if_carp);
+#endif
 	rt_ifmsg(ifp);
 #ifdef INET6
 	in6_if_up(ifp);