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Add bounds and option length checking.

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Use "%u", not "%d", for unsigned values.
This commit is contained in:
guy 2004-03-24 01:26:56 +00:00
parent 9bf8133f8d
commit 8b9bab2bd1
1 changed files with 43 additions and 26 deletions
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69
print-ip.c
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@ -21,7 +21,7 @@
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.133 2004-03-17 13:24:09 hannes Exp $ (LBL)";
"@(#) $Header: /tcpdump/master/tcpdump/print-ip.c,v 1.134 2004-03-24 01:26:56 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
@ -47,14 +47,19 @@ static const char rcsid[] _U_ =
static void
ip_printroute(const char *type, register const u_char *cp, u_int length)
{
register u_int ptr = cp[2] - 1;
register u_int ptr;
register u_int len;
if (length < 3) {
printf(" [bad length %u]", length);
return;
}
printf(" %s{", type);
if ((length + 1) & 3)
printf(" [bad length %d]", length);
printf(" [bad length %u]", length);
ptr = cp[2] - 1;
if (ptr < 3 || ((ptr + 1) & 3) || ptr > length + 1)
printf(" [bad ptr %d]", cp[2]);
printf(" [bad ptr %u]", cp[2]);
type = "";
for (len = 3; len < length; len += 4) {
@ -85,45 +90,54 @@ ip_finddst(const struct ip *ip)
length = (IP_HL(ip) << 2) - sizeof(struct ip);
for (; length > 0; cp += len, length -= len) {
int tt = *cp;
int tt;
TCHECK(*cp);
tt = *cp;
if (tt == IPOPT_NOP || tt == IPOPT_EOL)
len = 1;
else {
if (&cp[1] >= snapend) {
return 0;
}
TCHECK(cp[1]);
len = cp[1];
}
if (len <= 0) {
return 0;
}
if (&cp[1] >= snapend || cp + len > snapend) {
if (len < 2) {
return 0;
}
TCHECK2(*cp, len);
switch (tt) {
case IPOPT_SSRR:
case IPOPT_LSRR:
if (len < 7)
return 0;
memcpy(&retval, cp + len - 4, 4);
return retval;
}
}
return ip->ip_dst.s_addr;
trunc:
return 0;
}
static void
ip_printts(register const u_char *cp, u_int length)
{
register u_int ptr = cp[2] - 1;
register u_int len = 0;
register u_int ptr;
register u_int len;
int hoplen;
const char *type;
if (length < 4) {
printf("[bad length %d]", length);
return;
}
printf(" TS{");
hoplen = ((cp[3]&0xF) != IPOPT_TS_TSONLY) ? 8 : 4;
if ((length - 4) & (hoplen-1))
printf("[bad length %d]", length);
ptr = cp[2] - 1;
len = 0;
if (ptr < 4 || ((ptr - 4) & (hoplen-1)) || ptr > length + 1)
printf("[bad ptr %d]", cp[2]);
switch (cp[3]&0xF) {
@ -177,25 +191,21 @@ ip_optprint(register const u_char *cp, u_int length)
register u_int len;
for (; length > 0; cp += len, length -= len) {
int tt = *cp;
int tt;
TCHECK(*cp);
tt = *cp;
if (tt == IPOPT_NOP || tt == IPOPT_EOL)
len = 1;
else {
if (&cp[1] >= snapend) {
printf("[|ip]");
return;
}
TCHECK(cp[1]);
len = cp[1];
}
if (len <= 0) {
if (len < 2) {
printf("[|ip op len %d]", len);
return;
}
if (&cp[1] >= snapend || cp + len > snapend) {
printf("[|ip]");
return;
}
TCHECK2(*cp, len);
switch (tt) {
case IPOPT_EOL:
@ -238,8 +248,11 @@ ip_optprint(register const u_char *cp, u_int length)
printf(" RA");
if (len != 4)
printf("{%d}", len);
else if (cp[2] || cp[3])
printf("%d.%d", cp[2], cp[3]);
else {
TCHECK(cp[3]);
if (cp[2] || cp[3])
printf("%d.%d", cp[2], cp[3]);
}
break;
default:
@ -247,6 +260,10 @@ ip_optprint(register const u_char *cp, u_int length)
break;
}
}
return;
trunc:
printf("[|ip]");
}
/*