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devip: handle packet too big advise for icmp6, remove fragment header

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This commit is contained in:
cinap_lenrek 2019-03-04 03:13:29 +01:00
parent 2af6b08960
commit e2d310e623
1 changed files with 27 additions and 16 deletions
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43
sys/src/9/ip/icmp6.c
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@ -704,13 +704,28 @@ icmpiput6(Proto *icmp, Ipifc *ifc, Block *bp)
msg = unreachcode[Icmp6_unknown];
else
msg = unreachcode[p->code];
Advise:
bp->rp += IPICMPSZ;
if(BLEN(bp) < MinAdvise){
ipriv->stats[LenErrs6]++;
goto raise;
}
p = (IPICMP *)bp->rp;
/* get rid of fragment header if this is the first fragment */
if(p->proto == FH && BLEN(bp) >= MinAdvise+IP6FHDR && MinAdvise > IP6HDR){
Fraghdr6 *fh = (Fraghdr6*)(bp->rp + IP6HDR);
if((nhgets(fh->offsetRM) & ~7) == 0){ /* first fragment */
p->proto = fh->nexthdr;
/* copy down payload over fragment header */
bp->rp += IP6HDR;
bp->wp -= IP6FHDR;
memmove(bp->rp, bp->rp+IP6FHDR, BLEN(bp));
hnputs(p->ploadlen, BLEN(bp));
bp->rp -= IP6HDR;
}
}
pr = Fsrcvpcolx(icmp->f, p->proto);
if(pr != nil && pr->advise != nil) {
(*pr->advise)(pr, bp, msg);
@ -722,24 +737,21 @@ icmpiput6(Proto *icmp, Ipifc *ifc, Block *bp)
case TimeExceedV6:
if(p->code == 0){
sprint(m2, "ttl exceeded at %I", p->src);
bp->rp += IPICMPSZ;
if(BLEN(bp) < MinAdvise){
ipriv->stats[LenErrs6]++;
goto raise;
}
p = (IPICMP *)bp->rp;
pr = Fsrcvpcolx(icmp->f, p->proto);
if(pr != nil && pr->advise != nil) {
(*pr->advise)(pr, bp, m2);
return;
}
bp->rp -= IPICMPSZ;
snprint(msg = m2, sizeof m2, "ttl exceeded at %I", p->src);
goto Advise;
}
if(p->code == 1){
snprint(msg = m2, sizeof m2, "frag time exceeded at %I", p->src);
goto Advise;
}
goticmpkt6(icmp, bp, 0);
break;
case PacketTooBigV6:
snprint(msg = m2, sizeof(m2), "packet too big for %lud mtu at %I",
(ulong)nhgetl(p->icmpid), p->src);
goto Advise;
case RouterAdvert:
case RouterSolicit:
goticmpkt6(icmp, bp, p->type);
@ -793,7 +805,6 @@ icmpiput6(Proto *icmp, Ipifc *ifc, Block *bp)
freeblist(bp);
break;
case PacketTooBigV6:
default:
goticmpkt6(icmp, bp, 0);
break;