devip: fix fragment forwarding
unfraglen() had the side effect that it would always copy the nexthdr field from the fragment header to the previous nexthdr field. this is fine when we reassemble packets but breaks fragments that we want to just forward unchanged.front
parent
fa97c3dd10
commit
a1fceabd5b
|
@ -8,17 +8,12 @@
|
|||
#include "ip.h"
|
||||
#include "ipv6.h"
|
||||
|
||||
enum
|
||||
{
|
||||
IP6FHDR = 8, /* sizeof(Fraghdr6) */
|
||||
};
|
||||
|
||||
static Block* ip6reassemble(IP*, int, Block*);
|
||||
static Fragment6* ipfragallo6(IP*);
|
||||
static void ipfragfree6(IP*, Fragment6*);
|
||||
static Block* procopts(Block *bp);
|
||||
static Block* procxtns(IP *ip, Block *bp, int doreasm);
|
||||
static int unfraglen(Block *bp, uchar *nexthdr, int setfh);
|
||||
static int unfraglen(Block *bp, uchar *nexthdr, int setfh, int popfh);
|
||||
|
||||
void
|
||||
ip_init_6(Fs *f)
|
||||
|
@ -122,8 +117,14 @@ ipoput6(Fs *f, Block *bp, int gating, int ttl, int tos, Routehint *rh)
|
|||
}
|
||||
|
||||
/* start v6 fragmentation */
|
||||
uflen = unfraglen(bp, &nexthdr, 1);
|
||||
if(uflen < 0 || uflen > medialen) {
|
||||
uflen = unfraglen(bp, &nexthdr, 1, 0);
|
||||
if(uflen < IP6HDR || nexthdr == FH) {
|
||||
ip->stats[FragFails]++;
|
||||
ip->stats[OutDiscards]++;
|
||||
netlog(f, Logip, "%I -> %I: fragment header botch\n", eh->src, eh->dst);
|
||||
goto raise;
|
||||
}
|
||||
if(uflen > medialen) {
|
||||
ip->stats[FragFails]++;
|
||||
ip->stats[OutDiscards]++;
|
||||
netlog(f, Logip, "%I -> %I: unfragmentable part too big: %d\n", eh->src, eh->dst, uflen);
|
||||
|
@ -210,7 +211,6 @@ void
|
|||
ipiput6(Fs *f, Ipifc *ifc, Block *bp)
|
||||
{
|
||||
int hl, len, hop, tos;
|
||||
uchar proto;
|
||||
IP *ip;
|
||||
Ip6hdr *h;
|
||||
Proto *p;
|
||||
|
@ -301,8 +301,7 @@ ipiput6(Fs *f, Ipifc *ifc, Block *bp)
|
|||
return;
|
||||
|
||||
h = (Ip6hdr*)bp->rp;
|
||||
proto = h->proto;
|
||||
p = Fsrcvpcol(f, proto);
|
||||
p = Fsrcvpcol(f, h->proto);
|
||||
if(p != nil && p->rcv != nil) {
|
||||
ip->stats[InDelivers]++;
|
||||
(*p->rcv)(p, ifc, bp);
|
||||
|
@ -323,15 +322,15 @@ ipfragfree6(IP *ip, Fragment6 *frag)
|
|||
{
|
||||
Fragment6 *fl, **l;
|
||||
|
||||
if(frag->blist)
|
||||
if(frag->blist != nil)
|
||||
freeblist(frag->blist);
|
||||
|
||||
memset(frag->src, 0, IPaddrlen);
|
||||
frag->id = 0;
|
||||
frag->blist = nil;
|
||||
frag->id = 0;
|
||||
memset(frag->src, 0, IPaddrlen);
|
||||
memset(frag->dst, 0, IPaddrlen);
|
||||
|
||||
l = &ip->flisthead6;
|
||||
for(fl = *l; fl; fl = fl->next) {
|
||||
for(fl = *l; fl != nil; fl = fl->next) {
|
||||
if(fl == frag) {
|
||||
*l = frag->next;
|
||||
break;
|
||||
|
@ -353,7 +352,7 @@ ipfragallo6(IP *ip)
|
|||
|
||||
while(ip->fragfree6 == nil) {
|
||||
/* free last entry on fraglist */
|
||||
for(f = ip->flisthead6; f->next; f = f->next)
|
||||
for(f = ip->flisthead6; f->next != nil; f = f->next)
|
||||
;
|
||||
ipfragfree6(ip, f);
|
||||
}
|
||||
|
@ -372,16 +371,18 @@ procxtns(IP *ip, Block *bp, int doreasm)
|
|||
uchar proto;
|
||||
int offset;
|
||||
|
||||
offset = unfraglen(bp, &proto, 0);
|
||||
if(offset >= 0 && proto == FH && doreasm != 0) {
|
||||
offset = unfraglen(bp, &proto, 0, doreasm);
|
||||
if(offset >= IP6HDR && proto == FH && doreasm) {
|
||||
bp = ip6reassemble(ip, offset, bp);
|
||||
if(bp == nil)
|
||||
return nil;
|
||||
offset = unfraglen(bp, &proto, 0);
|
||||
offset = unfraglen(bp, &proto, 0, 0);
|
||||
if(proto == FH)
|
||||
offset = -1;
|
||||
}
|
||||
if(offset < 0){
|
||||
if(offset < IP6HDR){
|
||||
ip->stats[InHdrErrors]++;
|
||||
ip->stats[InDiscards]++;
|
||||
freeblist(bp);
|
||||
return nil;
|
||||
}
|
||||
|
@ -395,10 +396,12 @@ procxtns(IP *ip, Block *bp, int doreasm)
|
|||
* hop-by-hop & routing headers if present; *nexthdr is set to nexthdr value
|
||||
* of the last header in the "Unfragmentable part"; if setfh != 0, nexthdr
|
||||
* field of the last header in the "Unfragmentable part" is set to FH.
|
||||
* returns -1 on error.
|
||||
* When the last header is a fragment header and popfh != 0 then set
|
||||
* the nexthdr value of the previous header to the nexthdr value of the
|
||||
* fragment header. returns -1 on error.
|
||||
*/
|
||||
static int
|
||||
unfraglen(Block *bp, uchar *nexthdr, int setfh)
|
||||
unfraglen(Block *bp, uchar *nexthdr, int setfh, int popfh)
|
||||
{
|
||||
uchar *e, *p, *q;
|
||||
|
||||
|
@ -417,8 +420,9 @@ unfraglen(Block *bp, uchar *nexthdr, int setfh)
|
|||
if(p > e)
|
||||
return -1;
|
||||
if(*nexthdr == FH){
|
||||
if(setfh || p+IP6FHDR > e || *p == FH)
|
||||
if(p+IP6FHDR > e || *p == FH)
|
||||
return -1;
|
||||
if(popfh)
|
||||
*q = *p;
|
||||
} else if(setfh)
|
||||
*q = FH;
|
||||
|
@ -464,7 +468,7 @@ ip6reassemble(IP* ip, int uflen, Block* bp)
|
|||
*/
|
||||
for(f = ip->flisthead6; f != nil; f = fnext){
|
||||
fnext = f->next;
|
||||
if(ipcmp(f->src, src) == 0 && ipcmp(f->dst, dst) == 0 && f->id == id)
|
||||
if(f->id == id && ipcmp(f->src, src) == 0 && ipcmp(f->dst, dst) == 0)
|
||||
break;
|
||||
if(f->age < NOW){
|
||||
ip->stats[ReasmTimeout]++;
|
||||
|
@ -607,7 +611,6 @@ ip6reassemble(IP* ip, int uflen, Block* bp)
|
|||
|
||||
if(len >= IP_MAX){
|
||||
ipfragfree6(ip, f);
|
||||
|
||||
ip->stats[ReasmFails]++;
|
||||
qunlock(&ip->fraglock6);
|
||||
|
||||
|
|
|
@ -79,6 +79,7 @@ enum {
|
|||
v6MINTU = 1280,
|
||||
HOP_LIMIT = 255,
|
||||
IP6HDR = 40, /* sizeof(Ip6hdr) = 8 + 2*16 */
|
||||
IP6FHDR = 8, /* sizeof(Fraghdr6) */
|
||||
|
||||
/* option types */
|
||||
|
||||
|
|
Loading…
Reference in New Issue