Date: Sun, 4 Sep 2011 22:06:32 +0000 (UTC) From: Andrew Thompson <thompsa@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r225380 - head/sys/net Message-ID: <201109042206.p84M6W8e008867@svn.freebsd.org>
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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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