svn commit: r225380 - head/sys/net
Andrew Thompson
thompsa at FreeBSD.org
Sun Sep 4 22:06:32 UTC 2011
Author: thompsa
Date: Sun Sep 4 22:06:32 2011
New Revision: 225380
URL: http://svn.freebsd.org/changeset/base/225380
Log:
On the first loop for generating a bridge MAC address use the local
hostid, this gives a good chance of keeping the same address over
reboots. This is intended to help IPV6 and similar which generate
their addresses from the mac.
PR: kern/160300
Submitted by: mdodd
Approved by: re (kib)
Modified:
head/sys/net/if_bridge.c
Modified: head/sys/net/if_bridge.c
==============================================================================
--- head/sys/net/if_bridge.c Sun Sep 4 16:26:43 2011 (r225379)
+++ head/sys/net/if_bridge.c Sun Sep 4 22:06:32 2011 (r225380)
@@ -85,6 +85,7 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h>
#include <sys/protosw.h>
#include <sys/systm.h>
+#include <sys/jail.h>
#include <sys/time.h>
#include <sys/socket.h> /* for net/if.h */
#include <sys/sockio.h>
@@ -560,7 +561,8 @@ bridge_clone_create(struct if_clone *ifc
{
struct bridge_softc *sc, *sc2;
struct ifnet *bifp, *ifp;
- int retry;
+ int fb, retry;
+ unsigned long hostid;
sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK|M_ZERO);
ifp = sc->sc_ifp = if_alloc(IFT_ETHER);
@@ -593,17 +595,30 @@ bridge_clone_create(struct if_clone *ifc
IFQ_SET_READY(&ifp->if_snd);
/*
- * Generate a random ethernet address with a locally administered
- * address.
+ * Generate an ethernet address with a locally administered address.
*
* Since we are using random ethernet addresses for the bridge, it is
* possible that we might have address collisions, so make sure that
* this hardware address isn't already in use on another bridge.
+ * The first try uses the hostid and falls back to arc4rand().
*/
+ fb = 0;
+ getcredhostid(curthread->td_ucred, &hostid);
for (retry = 1; retry != 0;) {
- arc4rand(sc->sc_defaddr, ETHER_ADDR_LEN, 1);
- sc->sc_defaddr[0] &= ~1; /* clear multicast bit */
- sc->sc_defaddr[0] |= 2; /* set the LAA bit */
+ if (fb || hostid == 0) {
+ arc4rand(sc->sc_defaddr, ETHER_ADDR_LEN, 1);
+ sc->sc_defaddr[0] &= ~1;/* clear multicast bit */
+ sc->sc_defaddr[0] |= 2; /* set the LAA bit */
+ } else {
+ sc->sc_defaddr[0] = 0x2;
+ sc->sc_defaddr[1] = (hostid >> 24) & 0xff;
+ sc->sc_defaddr[2] = (hostid >> 16) & 0xff;
+ sc->sc_defaddr[3] = (hostid >> 8 ) & 0xff;
+ sc->sc_defaddr[4] = hostid & 0xff;
+ sc->sc_defaddr[5] = ifp->if_dunit & 0xff;
+ }
+
+ fb = 1;
retry = 0;
mtx_lock(&bridge_list_mtx);
LIST_FOREACH(sc2, &bridge_list, sc_list) {
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