A major overhaul of the CARP implementation. The ip_carp.c was started

from scratch, copying needed functionality from the old implemenation
on demand, with a thorough review of all code. The main change is that
interface layer has been removed from the CARP. Now redundant addresses
are configured exactly on the interfaces, they run on.

The CARP configuration itself is, as before, configured and read via
SIOCSVH/SIOCGVH ioctls. A new prefix created with SIOCAIFADDR or
SIOCAIFADDR_IN6 may now be configured to a particular virtual host id,
which makes the prefix redundant.

ifconfig(8) semantics has been changed too: now one doesn't need
to clone carpXX interface, he/she should directly configure a vhid
on a Ethernet interface.

To supply vhid data from the kernel to an application the getifaddrs(8)
function had been changed to pass ifam_data with each address. [1]

The new implementation definitely closes all PRs related to carp(4)
being an interface, and may close several others. It also allows
to run a single redundant IP per interface.

Big thanks to Bjoern Zeeb for his help with inet6 part of patch, for
idea on using ifam_data and for several rounds of reviewing!

PR:		kern/117000, kern/126945, kern/126714, kern/120130, kern/117448
Reviewed by:	bz
Submitted by:	bz [1]

1 files changed, 17 insertions, 5 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index 8c6c24c..4377343 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -130,17 +130,19 @@ void	(*lagg_linkstate_p)(struct ifnet *ifp, int state);
 /* These are external hooks for CARP. */
 void	(*carp_linkstate_p)(struct ifnet *ifp);
 #if defined(INET) || defined(INET6)
-struct ifnet *(*carp_forus_p)(struct ifnet *ifp, u_char *dhost);
+int	(*carp_forus_p)(struct ifnet *ifp, u_char *dhost);
 int	(*carp_output_p)(struct ifnet *ifp, struct mbuf *m,
-    struct sockaddr *sa, struct rtentry *rt);
+    struct sockaddr *sa);
+int	(*carp_ioctl_p)(struct ifreq *, u_long, struct thread *);   
+int	(*carp_attach_p)(struct ifaddr *, int);
+void	(*carp_detach_p)(struct ifaddr *);
 #endif
 #ifdef INET
-int (*carp_iamatch_p)(struct ifnet *, struct in_ifaddr *, struct in_addr *,
-    u_int8_t **);
+int	(*carp_iamatch_p)(struct ifaddr *, uint8_t **);
 #endif
 #ifdef INET6
 struct ifaddr *(*carp_iamatch6_p)(struct ifnet *ifp, struct in6_addr *taddr6);
-caddr_t (*carp_macmatch6_p)(struct ifnet *ifp, struct mbuf *m,
+caddr_t	(*carp_macmatch6_p)(struct ifnet *ifp, struct mbuf *m,
     const struct in6_addr *taddr);
 #endif
 
@@ -2506,6 +2508,16 @@ ifioctl(struct socket *so, u_long cmd, caddr_t data, struct thread *td)
 		error = if_getgroupmembers((struct ifgroupreq *)data);
 		CURVNET_RESTORE();
 		return (error);
+#if defined(INET) || defined(INET6)
+	case SIOCSVH:
+	case SIOCGVH:
+		if (carp_ioctl_p == NULL)
+			error = EPROTONOSUPPORT;
+		else
+			error = (*carp_ioctl_p)(ifr, cmd, td);
+		CURVNET_RESTORE();
+		return (error);
+#endif
 	}
 
 	ifp = ifunit_ref(ifr->ifr_name);