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devip: fix block list handling for icmp/icmp6, use proper MinAdvise for icmp6

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This commit is contained in:
cinap_lenrek 2019-03-03 09:01:23 +01:00
parent a2c0e55e68
commit a859f05837
2 changed files with 32 additions and 54 deletions
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43
sys/src/9/ip/icmp.c
View file

@ -44,11 +44,6 @@ enum { /* Packet Types */
Maxtype = 18,
};
enum
{
MinAdvise = 24, /* minimum needed for us to advise another protocol */
};
char *icmpnames[Maxtype+1] =
{
[EchoReply] "EchoReply",
@ -70,6 +65,8 @@ enum {
IP_ICMPPROTO = 1,
ICMP_IPSIZE = 20,
ICMP_HDRSIZE = 8,
MinAdvise = ICMP_IPSIZE+4, /* minimum needed for us to advise another protocol */
};
enum
@ -169,8 +166,7 @@ icmpkick(void *x, Block *bp)
if(bp == nil)
return;
if(blocklen(bp) < ICMP_IPSIZE + ICMP_HDRSIZE){
if(BLEN(bp) < ICMP_IPSIZE + ICMP_HDRSIZE){
freeblist(bp);
return;
}
@ -350,7 +346,7 @@ static char *unreachcode[] =
static void
icmpiput(Proto *icmp, Ipifc*, Block *bp)
{
int n, iplen;
int n;
Icmp *p;
Block *r;
Proto *pr;
@ -359,42 +355,31 @@ icmpiput(Proto *icmp, Ipifc*, Block *bp)
Icmppriv *ipriv;
ipriv = icmp->priv;
ipriv->stats[InMsgs]++;
p = (Icmp *)bp->rp;
netlog(icmp->f, Logicmp, "icmpiput %s (%d) %d\n",
(p->type < nelem(icmpnames)? icmpnames[p->type]: ""),
p->type, p->code);
n = blocklen(bp);
bp = concatblock(bp);
n = BLEN(bp);
if(n < ICMP_IPSIZE+ICMP_HDRSIZE){
ipriv->stats[InErrors]++;
ipriv->stats[HlenErrs]++;
netlog(icmp->f, Logicmp, "icmp hlen %d\n", n);
goto raise;
}
iplen = nhgets(p->length);
if(iplen > n){
ipriv->stats[LenErrs]++;
ipriv->stats[InErrors]++;
netlog(icmp->f, Logicmp, "icmp length %d\n", iplen);
goto raise;
}
if(ptclcsum(bp, ICMP_IPSIZE, iplen - ICMP_IPSIZE)){
if(ptclcsum(bp, ICMP_IPSIZE, n - ICMP_IPSIZE)){
ipriv->stats[InErrors]++;
ipriv->stats[CsumErrs]++;
netlog(icmp->f, Logicmp, "icmp checksum error\n");
goto raise;
}
p = (Icmp *)bp->rp;
netlog(icmp->f, Logicmp, "icmpiput %s (%d) %d\n",
(p->type < nelem(icmpnames)? icmpnames[p->type]: ""),
p->type, p->code);
if(p->type <= Maxtype)
ipriv->in[p->type]++;
switch(p->type) {
case EchoRequest:
if(iplen < n)
bp = trimblock(bp, 0, iplen);
if(bp->next != nil)
bp = concatblock(bp);
r = mkechoreply(bp, icmp->f);
if(r == nil)
goto raise;
@ -410,7 +395,7 @@ icmpiput(Proto *icmp, Ipifc*, Block *bp)
msg = unreachcode[p->code];
bp->rp += ICMP_IPSIZE+ICMP_HDRSIZE;
if(blocklen(bp) < MinAdvise){
if(BLEN(bp) < MinAdvise){
ipriv->stats[LenErrs]++;
goto raise;
}
@ -420,7 +405,6 @@ icmpiput(Proto *icmp, Ipifc*, Block *bp)
(*pr->advise)(pr, bp, msg);
return;
}
bp->rp -= ICMP_IPSIZE+ICMP_HDRSIZE;
goticmpkt(icmp, bp);
break;
@ -429,7 +413,7 @@ icmpiput(Proto *icmp, Ipifc*, Block *bp)
snprint(m2, sizeof m2, "ttl exceeded at %V", p->src);
bp->rp += ICMP_IPSIZE+ICMP_HDRSIZE;
if(blocklen(bp) < MinAdvise){
if(BLEN(bp) < MinAdvise){
ipriv->stats[LenErrs]++;
goto raise;
}
@ -441,7 +425,6 @@ icmpiput(Proto *icmp, Ipifc*, Block *bp)
}
bp->rp -= ICMP_IPSIZE+ICMP_HDRSIZE;
}
goticmpkt(icmp, bp);
break;
default:

43
sys/src/9/ip/icmp6.c
View file

@ -67,6 +67,10 @@ enum {
Maxtype6 = 137,
};
enum {
MinAdvise = IP6HDR+4, /* minimum needed for us to advise another protocol */
};
/* on-the-wire packet formats */
typedef struct IPICMP IPICMP;
typedef struct Ndpkt Ndpkt;
@ -189,13 +193,14 @@ static void
set_cksum(Block *bp)
{
IPICMP *p = (IPICMP *)(bp->rp);
int n = blocklen(bp);
hnputl(p->vcf, 0); /* borrow IP header as pseudoheader */
hnputs(p->ploadlen, blocklen(bp) - IP6HDR);
hnputs(p->ploadlen, n - IP6HDR);
p->proto = 0;
p->ttl = ICMPv6; /* ttl gets set later */
hnputs(p->cksum, 0);
hnputs(p->cksum, ptclcsum(bp, 0, blocklen(bp)));
hnputs(p->cksum, ptclcsum(bp, 0, n));
p->proto = ICMPv6;
}
@ -259,7 +264,7 @@ icmpkick6(void *x, Block *bp)
bp = padblock(bp, IP6HDR);
}
if(blocklen(bp) < IPICMPSZ){
if(BLEN(bp) < IPICMPSZ){
freeblist(bp);
return;
}
@ -524,26 +529,17 @@ icmppkttoobig6(Fs *f, Ipifc *ifc, Block *bp)
* RFC 2461, pages 39-40, pages 57-58.
*/
static int
valid(Proto *icmp, Ipifc *ifc, Block *bp, Icmppriv6 *ipriv)
valid(Proto *icmp, Ipifc *, Block *bp, Icmppriv6 *ipriv)
{
int sz, osz, unsp, n, ttl, iplen;
int sz, osz, unsp, ttl;
int pktsz = BLEN(bp);
uchar *packet = bp->rp;
IPICMP *p = (IPICMP *) packet;
Ndpkt *np;
USED(ifc);
n = blocklen(bp);
if(n < IPICMPSZ) {
if(pktsz < IPICMPSZ) {
ipriv->stats[HlenErrs6]++;
netlog(icmp->f, Logicmp, "icmp hlen %d\n", n);
goto err;
}
iplen = nhgets(p->ploadlen);
if(iplen > n - IP6HDR) {
ipriv->stats[LenErrs6]++;
netlog(icmp->f, Logicmp, "icmp length %d\n", iplen);
netlog(icmp->f, Logicmp, "icmp hlen %d\n", pktsz);
goto err;
}
@ -557,7 +553,7 @@ valid(Proto *icmp, Ipifc *ifc, Block *bp, Icmppriv6 *ipriv)
ttl = p->ttl;
p->ttl = p->proto;
p->proto = 0;
if(ptclcsum(bp, 0, iplen + IP6HDR)) {
if(ptclcsum(bp, 0, pktsz)) {
ipriv->stats[CsumErrs6]++;
netlog(icmp->f, Logicmp, "icmp checksum error\n");
goto err;
@ -678,15 +674,17 @@ icmpiput6(Proto *icmp, Ipifc *ifc, Block *bp)
{
char *msg, m2[128];
uchar pktflags;
uchar *packet = bp->rp;
uchar ia[IPaddrlen];
Block *r;
IPICMP *p = (IPICMP *)packet;
IPICMP *p;
Icmppriv6 *ipriv = icmp->priv;
Iplifc *lifc;
Ndpkt* np;
Proto *pr;
bp = concatblock(bp);
p = (IPICMP*)bp->rp;
if(!valid(icmp, ifc, bp, ipriv) || p->type > Maxtype6)
goto raise;
@ -694,8 +692,6 @@ icmpiput6(Proto *icmp, Ipifc *ifc, Block *bp)
switch(p->type) {
case EchoRequestV6:
if(bp->next != nil)
bp = concatblock(bp);
r = mkechoreply6(bp, ifc);
if(r == nil)
goto raise;
@ -710,7 +706,7 @@ icmpiput6(Proto *icmp, Ipifc *ifc, Block *bp)
msg = unreachcode[p->code];
bp->rp += IPICMPSZ;
if(blocklen(bp) < 8){
if(BLEN(bp) < MinAdvise){
ipriv->stats[LenErrs6]++;
goto raise;
}
@ -720,7 +716,6 @@ icmpiput6(Proto *icmp, Ipifc *ifc, Block *bp)
(*pr->advise)(pr, bp, msg);
return;
}
bp->rp -= IPICMPSZ;
goticmpkt6(icmp, bp, 0);
break;
@ -730,7 +725,7 @@ icmpiput6(Proto *icmp, Ipifc *ifc, Block *bp)
sprint(m2, "ttl exceeded at %I", p->src);
bp->rp += IPICMPSZ;
if(blocklen(bp) < 8){
if(BLEN(bp) < MinAdvise){
ipriv->stats[LenErrs6]++;
goto raise;
}