Decouple the UUID generator from network interfaces by having MAC

addresses added to the UUID generator using uuid_ether_add(). The
UUID generator keeps an arbitrary number of MAC addresses, under
the assumption that they are rarely removed (= uuid_ether_del()).
This achieves the following:
1.  It brings up closer to having the network stack as a loadable
    module.
2.  It allows the UUID generator to filter MAC addresses for best
    results (= highest chance of uniqeness).
3.  MAC addresses can come from anywhere, irrespactive of whether
    it's used for an interface or not.

A side-effect of the change is that when no MAC addresses have been
added, a random multicast MAC address is created once and re-used if
needed. Previusly, when a random MAC address was needed, it was
created for every call. Thus, a change in behaviour is introduced
for when no MAC addresses exist.

Obtained from:	Juniper Networks, Inc.

1 files changed, 8 insertions, 0 deletions

diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 3fd6c9d..4f9672d 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -48,6 +48,7 @@
 #include <sys/socket.h>
 #include <sys/sockio.h>
 #include <sys/sysctl.h>
+#include <sys/uuid.h>
 
 #include <net/if.h>
 #include <net/if_arp.h>
@@ -926,6 +927,8 @@ ether_ifattach(struct ifnet *ifp, const u_int8_t *lla)
 			break; 
 	if (i != ifp->if_addrlen)
 		if_printf(ifp, "Ethernet address: %6D\n", lla, ":");
+
+	uuid_ether_add(LLADDR(sdl));
 }
 
 /*
@@ -934,6 +937,11 @@ ether_ifattach(struct ifnet *ifp, const u_int8_t *lla)
 void
 ether_ifdetach(struct ifnet *ifp)
 {
+	struct sockaddr_dl *sdl;
+
+	sdl = (struct sockaddr_dl *)(ifp->if_addr->ifa_addr);
+	uuid_ether_del(LLADDR(sdl));
+
 	if (IFP2AC(ifp)->ac_netgraph != NULL) {
 		KASSERT(ng_ether_detach_p != NULL,
 		    ("ng_ether_detach_p is NULL"));