From de9141bc6d0d0d51abc39cd6b7e199c9ddf18010 Mon Sep 17 00:00:00 2001 From: cinap_lenrek Date: Thu, 14 Jun 2018 00:07:45 +0200 Subject: devip: don't send arp requests from null address during dhcp, ipconfig assigns the null address :: which makes ipforme() return Runi for any destination, which can trigger arp resolution when we attempt to reply. so have v4local() skip the null address and have sendarp() check the return status of v4local(), avoing the spurious arp requests. --- sys/src/9/ip/ethermedium.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'sys/src/9/ip/ethermedium.c') diff --git a/sys/src/9/ip/ethermedium.c b/sys/src/9/ip/ethermedium.c index 3aa74f42f..6471355c1 100644 --- a/sys/src/9/ip/ethermedium.c +++ b/sys/src/9/ip/ethermedium.c @@ -449,6 +449,7 @@ sendarp(Ipifc *ifc, Arpent *a) Block *bp; Etherarp *e; Etherrock *er = ifc->arg; + uchar targ[IPv4addrlen], src[IPv4addrlen]; /* don't do anything if it's been less than a second since the last */ if(NOW - a->ctime < 1000){ @@ -456,6 +457,9 @@ sendarp(Ipifc *ifc, Arpent *a) return; } + /* try to keep it around for a second more */ + a->ctime = NOW; + /* remove all but the last message */ while((bp = a->hold) != nil){ if(bp == a->last) @@ -464,18 +468,20 @@ sendarp(Ipifc *ifc, Arpent *a) freeblist(bp); } - /* try to keep it around for a second more */ - a->ctime = NOW; + memmove(targ, a->ip+IPv4off, IPv4addrlen); arprelease(er->f->arp, a); + if(!ipv4local(ifc, src, targ)) + return; + n = sizeof(Etherarp); if(n < ifc->m->mintu) n = ifc->m->mintu; bp = allocb(n); memset(bp->rp, 0, n); e = (Etherarp*)bp->rp; - memmove(e->tpa, a->ip+IPv4off, sizeof(e->tpa)); - ipv4local(ifc, e->spa, e->tpa); + memmove(e->tpa, targ, sizeof(e->tpa)); + memmove(e->spa, src, sizeof(e->spa)); memmove(e->sha, ifc->mac, sizeof(e->sha)); memset(e->d, 0xff, sizeof(e->d)); /* ethernet broadcast */ memmove(e->s, ifc->mac, sizeof(e->s)); -- cgit v1.2.3