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mirror of https://git.FreeBSD.org/src.git synced 2024-12-12 09:58:36 +00:00

Reviewed by: freebsd-current

Add bounds checking to netbios NS packet resolving code.  This should
    prevent natd from crashing on badly formed netbios packets (as might be
    heard when the machine is sitting on a cable modem or certain DSL
    networks), and also closes potential security holes that might have
    exploited the lack of bounds checking in the previous version of the
    code.
This commit is contained in:
Matthew Dillon 1998-12-14 02:25:32 +00:00
parent d749f6f64f
commit 374fad8b17
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=41759
6 changed files with 384 additions and 88 deletions

View File

@ -73,6 +73,9 @@
- Eliminated PacketAliasIn2() and
PacketAliasOut2() as poorly conceived.
Version 2.3 Dec 1998 (dillon)
- Major bounds checking additions, see FreeBSD/CVS
See HISTORY file for additional revisions.
*/
@ -603,6 +606,7 @@ UdpAliasIn(struct ip *pip)
u_short alias_port;
int accumulate;
u_short *sptr;
int r = 0;
alias_address = GetAliasAddress(link);
original_address = GetOriginalAddress(link);
@ -613,11 +617,11 @@ UdpAliasIn(struct ip *pip)
if (ntohs(ud->uh_dport) == NETBIOS_DGM_PORT_NUMBER
|| ntohs(ud->uh_sport) == NETBIOS_DGM_PORT_NUMBER )
{
AliasHandleUdpNbt(pip, link, &original_address, ud->uh_dport);
r = AliasHandleUdpNbt(pip, link, &original_address, ud->uh_dport);
} else if (ntohs(ud->uh_dport) == NETBIOS_NS_PORT_NUMBER
|| ntohs(ud->uh_sport) == NETBIOS_NS_PORT_NUMBER )
{
AliasHandleUdpNbtNS(pip, link,
r = AliasHandleUdpNbtNS(pip, link,
&alias_address,
&alias_port,
&original_address,
@ -648,7 +652,14 @@ UdpAliasIn(struct ip *pip)
(u_short *) &pip->ip_dst,
2);
pip->ip_dst = original_address;
return(PKT_ALIAS_OK);
/*
* If we cannot figure out the packet, ignore it.
*/
if (r < 0)
return(PKT_ALIAS_IGNORED);
else
return(PKT_ALIAS_OK);
}
return(PKT_ALIAS_IGNORED);
}

View File

@ -90,8 +90,8 @@ void HouseKeeping(void);
/*lint -save -library Suppress flexelint warnings */
void AliasHandleFtpOut(struct ip *, struct alias_link *, int);
void AliasHandleIrcOut(struct ip *pip, struct alias_link *link, int maxsize );
void AliasHandleUdpNbt(struct ip *, struct alias_link *, struct in_addr *, u_short);
void AliasHandleUdpNbtNS(struct ip *, struct alias_link *, struct in_addr *, u_short *, struct in_addr *, u_short *);
int AliasHandleUdpNbt(struct ip *, struct alias_link *, struct in_addr *, u_short);
int AliasHandleUdpNbtNS(struct ip *, struct alias_link *, struct in_addr *, u_short *, struct in_addr *, u_short *);
void AliasHandleCUSeeMeOut(struct ip *, struct alias_link *);
void AliasHandleCUSeeMeIn(struct ip *, struct in_addr);

View File

@ -15,7 +15,7 @@
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Id:$
* $Id: alias_nbt.c,v 1.1 1998/05/24 03:03:10 amurai Exp $
*
* TODO:
* oClean up.
@ -132,15 +132,21 @@ void PrintRcode( u_char rcode ) {
/* Handling Name field */
u_char *AliasHandleName ( u_char *p ) {
u_char *AliasHandleName ( u_char *p, char *pmax ) {
u_char *s;
u_char c;
int compress;
/* Following length field */
if (p == NULL || (char *)p >= pmax)
return(NULL);
if (*p & 0xc0 ) {
p = p + 2;
if ((char *)p > pmax)
return(NULL);
return ((u_char *)p);
}
while ( ( *p & 0x3f) != 0x00 ) {
@ -152,6 +158,10 @@ u_char *AliasHandleName ( u_char *p ) {
/* Get next length field */
p = (u_char *)(p + (*p & 0x3f) + 1);
if ((char *)p > pmax) {
p = NULL;
break;
}
#ifdef DEBUG
printf(":");
#endif
@ -179,7 +189,10 @@ u_char *AliasHandleName ( u_char *p ) {
}
/* Set up to out of Name field */
p++;
if (p == NULL || (char *)p >= pmax)
p = NULL;
else
p++;
return ((u_char *)p);
}
@ -194,19 +207,24 @@ u_char *AliasHandleName ( u_char *p ) {
#define DGM_POSITIVE_RES 0x15
#define DGM_NEGATIVE_RES 0x16
void AliasHandleUdpNbt(
int AliasHandleUdpNbt(
struct ip *pip, /* IP packet to examine/patch */
struct alias_link *link,
struct in_addr *alias_address,
u_short alias_port )
{
u_short alias_port
) {
struct udphdr * uh;
NbtDataHeader *ndh;
u_char *p;
u_char *p = NULL;
char *pmax;
/* Calculate data length of UDP packet */
uh = (struct udphdr *) ((char *) pip + (pip->ip_hl << 2));
pmax = (char *)uh + ntohs( uh->uh_ulen );
ndh = (NbtDataHeader *)((char *)uh + (sizeof (struct udphdr)));
if ((char *)(ndh + 1) > pmax)
return(-1);
#ifdef DEBUG
printf("\nType=%02x,", ndh->type );
#endif
@ -215,8 +233,8 @@ void AliasHandleUdpNbt(
case DGM_DIRECT_GROUP:
case DGM_BROADCAST:
p = (u_char *)ndh + 14;
p = AliasHandleName ( p ); /* Source Name */
p = AliasHandleName ( p ); /* Destination Name */
p = AliasHandleName ( p, pmax ); /* Source Name */
p = AliasHandleName ( p, pmax ); /* Destination Name */
break;
case DGM_ERROR:
p = (u_char *)ndh + 11;
@ -225,9 +243,11 @@ void AliasHandleUdpNbt(
case DGM_POSITIVE_RES:
case DGM_NEGATIVE_RES:
p = (u_char *)ndh + 10;
p = AliasHandleName ( p ); /* Destination Name */
p = AliasHandleName ( p, pmax ); /* Destination Name */
break;
}
if (p == NULL || (char *)p > pmax)
p = NULL;
#ifdef DEBUG
printf("%s:%d-->", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port) );
#endif
@ -251,6 +271,7 @@ void AliasHandleUdpNbt(
printf("%s:%d\n", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port) );
fflush(stdout);
#endif
return((p == NULL) ? -1 : 0);
}
/* Question Section */
#define QS_TYPE_NB 0x0020
@ -261,14 +282,22 @@ typedef struct {
u_short class; /* The class of Request */
} NBTNsQuestion;
u_char *AliasHandleQuestion(u_short count,
u_char *
AliasHandleQuestion(
u_short count,
NBTNsQuestion *q,
char *pmax,
NBTArguments *nbtarg)
{
while ( count != 0 ) {
/* Name Filed */
q = (NBTNsQuestion *)AliasHandleName((u_char *)q );
q = (NBTNsQuestion *)AliasHandleName((u_char *)q, pmax);
if (q == NULL || (char *)(q + 1) > pmax) {
q = NULL;
break;
}
/* Type and Class filed */
switch ( ntohs(q->type) ) {
@ -308,12 +337,17 @@ typedef struct {
struct in_addr addr;
} NBTNsRNB;
u_char *AliasHandleResourceNB( NBTNsResource *q,
u_char *
AliasHandleResourceNB(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsRNB *nb;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Check out a length */
bcount = ntohs(q->rdlen);
@ -325,7 +359,11 @@ u_char *AliasHandleResourceNB( NBTNsResource *q,
printf("NB rec[%s", inet_ntoa(nbtarg->oldaddr));
printf("->%s, %dbytes] ",inet_ntoa(nbtarg->newaddr ), bcount);
#endif
while ( bcount != 0 ) {
while ( nb != NULL && bcount != 0 ) {
if ((char *)(nb + 1) > pmax) {
nb = NULL;
break;
}
#ifdef DEBUG
printf("<%s>", inet_ntoa(nb->addr) );
#endif
@ -356,6 +394,9 @@ u_char *AliasHandleResourceNB( NBTNsResource *q,
nb=(NBTNsRNB *)((u_char *)nb + SizeOfNsRNB);
bcount -= SizeOfNsRNB;
}
if (nb == NULL || (char *)(nb + 1) > pmax) {
nb = NULL;
}
return ((u_char *)nb);
}
@ -365,12 +406,18 @@ typedef struct {
struct in_addr addr;
} NBTNsResourceA;
u_char *AliasHandleResourceA( NBTNsResource *q,
u_char *
AliasHandleResourceA(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsResourceA *a;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Forward to Resource A position */
a = (NBTNsResourceA *)( (u_char *)q + sizeof(NBTNsResource) );
@ -383,6 +430,8 @@ u_char *AliasHandleResourceA( NBTNsResource *q,
printf("->%s]",inet_ntoa(nbtarg->newaddr ));
#endif
while ( bcount != 0 ) {
if (a == NULL || (char *)(a + 1) > pmax)
return(NULL);
#ifdef DEBUG
printf("..%s", inet_ntoa(a->addr) );
#endif
@ -405,6 +454,8 @@ u_char *AliasHandleResourceA( NBTNsResource *q,
a++; /*XXXX*/
bcount -= SizeOfResourceA;
}
if (a == NULL || (char *)(a + 1) > pmax)
a = NULL;
return ((u_char *)a);
}
@ -412,12 +463,18 @@ typedef struct {
u_short opcode:4, flags:8, resv:4;
} NBTNsResourceNULL;
u_char *AliasHandleResourceNULL( NBTNsResource *q,
u_char *
AliasHandleResourceNULL(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsResourceNULL *n;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Forward to Resource NULL position */
n = (NBTNsResourceNULL *)( (u_char *)q + sizeof(NBTNsResource) );
@ -426,19 +483,31 @@ u_char *AliasHandleResourceNULL( NBTNsResource *q,
/* Processing all in_addr array */
while ( bcount != 0 ) {
if ((char *)(n + 1) > pmax) {
n = NULL;
break;
}
n++;
bcount -= sizeof(NBTNsResourceNULL);
}
if ((char *)(n + 1) > pmax)
n = NULL;
return ((u_char *)n);
}
u_char *AliasHandleResourceNS( NBTNsResource *q,
u_char *
AliasHandleResourceNS(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsResourceNULL *n;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Forward to Resource NULL position */
n = (NBTNsResourceNULL *)( (u_char *)q + sizeof(NBTNsResource) );
@ -446,8 +515,11 @@ u_char *AliasHandleResourceNS( NBTNsResource *q,
bcount = ntohs(q->rdlen);
/* Resource Record Name Filed */
q = (NBTNsResource *)AliasHandleName( (u_char *)n ); /* XXX */
q = (NBTNsResource *)AliasHandleName( (u_char *)n, pmax ); /* XXX */
if (q == NULL || (char *)((u_char *)n + bcount) > pmax)
return(NULL);
else
return ((u_char *)n + bcount);
}
@ -455,28 +527,44 @@ typedef struct {
u_short numnames;
} NBTNsResourceNBSTAT;
u_char *AliasHandleResourceNBSTAT( NBTNsResource *q,
u_char *
AliasHandleResourceNBSTAT(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsResourceNBSTAT *n;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Forward to Resource NBSTAT position */
n = (NBTNsResourceNBSTAT *)( (u_char *)q + sizeof(NBTNsResource) );
/* Check out of length */
bcount = ntohs(q->rdlen);
if (q == NULL || (char *)((u_char *)n + bcount) > pmax)
return(NULL);
else
return ((u_char *)n + bcount);
}
u_char *AliasHandleResource(u_short count,
u_char *
AliasHandleResource(
u_short count,
NBTNsResource *q,
NBTArguments *nbtarg)
char *pmax,
NBTArguments
*nbtarg)
{
while ( count != 0 ) {
/* Resource Record Name Filed */
q = (NBTNsResource *)AliasHandleName( (u_char *)q );
q = (NBTNsResource *)AliasHandleName( (u_char *)q, pmax );
if (q == NULL || (char *)(q + 1) > pmax)
break;
#ifdef DEBUG
printf("type=%02x, count=%d\n", ntohs(q->type), count );
#endif
@ -484,22 +572,45 @@ u_char *AliasHandleResource(u_short count,
/* Type and Class filed */
switch ( ntohs(q->type) ) {
case RR_TYPE_NB:
q = (NBTNsResource *)AliasHandleResourceNB( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceNB(
q,
pmax,
nbtarg
);
break;
case RR_TYPE_A:
q = (NBTNsResource *)AliasHandleResourceA( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceA(
q,
pmax,
nbtarg
);
break;
case RR_TYPE_NS:
q = (NBTNsResource *)AliasHandleResourceNS( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceNS(
q,
pmax,
nbtarg
);
break;
case RR_TYPE_NULL:
q = (NBTNsResource *)AliasHandleResourceNULL( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceNULL(
q,
pmax,
nbtarg
);
break;
case RR_TYPE_NBSTAT:
q = (NBTNsResource *)AliasHandleResourceNBSTAT( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceNBSTAT(
q,
pmax,
nbtarg
);
break;
default: printf("\nUnknown Type of Resource %0x\n",
ntohs(q->type) );
default:
printf(
"\nUnknown Type of Resource %0x\n",
ntohs(q->type)
);
break;
}
count--;
@ -508,7 +619,7 @@ u_char *AliasHandleResource(u_short count,
return ((u_char *)q);
}
void AliasHandleUdpNbtNS(
int AliasHandleUdpNbtNS(
struct ip *pip, /* IP packet to examine/patch */
struct alias_link *link,
struct in_addr *alias_address,
@ -518,8 +629,8 @@ void AliasHandleUdpNbtNS(
{
struct udphdr * uh;
NbtNSHeader * nsh;
u_short dlen;
u_char * p;
char *pmax;
NBTArguments nbtarg;
/* Set up Common Parameter */
@ -531,12 +642,16 @@ void AliasHandleUdpNbtNS(
/* Calculate data length of UDP packet */
uh = (struct udphdr *) ((char *) pip + (pip->ip_hl << 2));
nbtarg.uh_sum = &(uh->uh_sum);
dlen = ntohs( uh->uh_ulen );
nsh = (NbtNSHeader *)((char *)uh + (sizeof(struct udphdr)));
p = (u_char *)(nsh + 1);
pmax = (char *)uh + ntohs( uh->uh_ulen );
if ((char *)(nsh + 1) > pmax)
return(-1);
#ifdef DEBUG
printf(" [%s] ID=%02x, op=%01x, flag=%02x, rcode=%01x, qd=%04x, an=%04x, ns=%04x, ar=%04x, [%d]-->",
printf(" [%s] ID=%02x, op=%01x, flag=%02x, rcode=%01x, qd=%04x"
", an=%04x, ns=%04x, ar=%04x, [%d]-->",
nsh->dir ? "Response": "Request",
nsh->nametrid,
nsh->opcode,
@ -546,31 +661,53 @@ void AliasHandleUdpNbtNS(
ntohs(nsh->ancount),
ntohs(nsh->nscount),
ntohs(nsh->arcount),
(u_char *)p -(u_char *)nsh);
(u_char *)p -(u_char *)nsh
);
#endif
/* Question Entries */
if (ntohs(nsh->qdcount) !=0 ) {
p = AliasHandleQuestion(ntohs(nsh->qdcount), (NBTNsQuestion *)p, &nbtarg );
p = AliasHandleQuestion(
ntohs(nsh->qdcount),
(NBTNsQuestion *)p,
pmax,
&nbtarg
);
}
/* Answer Resource Records */
if (ntohs(nsh->ancount) !=0 ) {
p = AliasHandleResource(ntohs(nsh->ancount), (NBTNsResource *)p, &nbtarg );
p = AliasHandleResource(
ntohs(nsh->ancount),
(NBTNsResource *)p,
pmax,
&nbtarg
);
}
/* Authority Resource Recodrs */
if (ntohs(nsh->nscount) !=0 ) {
p = AliasHandleResource(ntohs(nsh->nscount), (NBTNsResource *)p, &nbtarg );
p = AliasHandleResource(
ntohs(nsh->nscount),
(NBTNsResource *)p,
pmax,
&nbtarg
);
}
/* Additional Resource Recodrs */
if (ntohs(nsh->arcount) !=0 ) {
p = AliasHandleResource(ntohs(nsh->arcount), (NBTNsResource *)p, &nbtarg );
p = AliasHandleResource(
ntohs(nsh->arcount),
(NBTNsResource *)p,
pmax,
&nbtarg
);
}
#ifdef DEBUG
PrintRcode(nsh->rcode);
#endif
return;
return ((p == NULL) ? -1 : 0);
}

View File

@ -73,6 +73,9 @@
- Eliminated PacketAliasIn2() and
PacketAliasOut2() as poorly conceived.
Version 2.3 Dec 1998 (dillon)
- Major bounds checking additions, see FreeBSD/CVS
See HISTORY file for additional revisions.
*/
@ -603,6 +606,7 @@ UdpAliasIn(struct ip *pip)
u_short alias_port;
int accumulate;
u_short *sptr;
int r = 0;
alias_address = GetAliasAddress(link);
original_address = GetOriginalAddress(link);
@ -613,11 +617,11 @@ UdpAliasIn(struct ip *pip)
if (ntohs(ud->uh_dport) == NETBIOS_DGM_PORT_NUMBER
|| ntohs(ud->uh_sport) == NETBIOS_DGM_PORT_NUMBER )
{
AliasHandleUdpNbt(pip, link, &original_address, ud->uh_dport);
r = AliasHandleUdpNbt(pip, link, &original_address, ud->uh_dport);
} else if (ntohs(ud->uh_dport) == NETBIOS_NS_PORT_NUMBER
|| ntohs(ud->uh_sport) == NETBIOS_NS_PORT_NUMBER )
{
AliasHandleUdpNbtNS(pip, link,
r = AliasHandleUdpNbtNS(pip, link,
&alias_address,
&alias_port,
&original_address,
@ -648,7 +652,14 @@ UdpAliasIn(struct ip *pip)
(u_short *) &pip->ip_dst,
2);
pip->ip_dst = original_address;
return(PKT_ALIAS_OK);
/*
* If we cannot figure out the packet, ignore it.
*/
if (r < 0)
return(PKT_ALIAS_IGNORED);
else
return(PKT_ALIAS_OK);
}
return(PKT_ALIAS_IGNORED);
}

View File

@ -90,8 +90,8 @@ void HouseKeeping(void);
/*lint -save -library Suppress flexelint warnings */
void AliasHandleFtpOut(struct ip *, struct alias_link *, int);
void AliasHandleIrcOut(struct ip *pip, struct alias_link *link, int maxsize );
void AliasHandleUdpNbt(struct ip *, struct alias_link *, struct in_addr *, u_short);
void AliasHandleUdpNbtNS(struct ip *, struct alias_link *, struct in_addr *, u_short *, struct in_addr *, u_short *);
int AliasHandleUdpNbt(struct ip *, struct alias_link *, struct in_addr *, u_short);
int AliasHandleUdpNbtNS(struct ip *, struct alias_link *, struct in_addr *, u_short *, struct in_addr *, u_short *);
void AliasHandleCUSeeMeOut(struct ip *, struct alias_link *);
void AliasHandleCUSeeMeIn(struct ip *, struct in_addr);

View File

@ -15,7 +15,7 @@
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Id:$
* $Id: alias_nbt.c,v 1.1 1998/05/24 03:03:10 amurai Exp $
*
* TODO:
* oClean up.
@ -132,15 +132,21 @@ void PrintRcode( u_char rcode ) {
/* Handling Name field */
u_char *AliasHandleName ( u_char *p ) {
u_char *AliasHandleName ( u_char *p, char *pmax ) {
u_char *s;
u_char c;
int compress;
/* Following length field */
if (p == NULL || (char *)p >= pmax)
return(NULL);
if (*p & 0xc0 ) {
p = p + 2;
if ((char *)p > pmax)
return(NULL);
return ((u_char *)p);
}
while ( ( *p & 0x3f) != 0x00 ) {
@ -152,6 +158,10 @@ u_char *AliasHandleName ( u_char *p ) {
/* Get next length field */
p = (u_char *)(p + (*p & 0x3f) + 1);
if ((char *)p > pmax) {
p = NULL;
break;
}
#ifdef DEBUG
printf(":");
#endif
@ -179,7 +189,10 @@ u_char *AliasHandleName ( u_char *p ) {
}
/* Set up to out of Name field */
p++;
if (p == NULL || (char *)p >= pmax)
p = NULL;
else
p++;
return ((u_char *)p);
}
@ -194,19 +207,24 @@ u_char *AliasHandleName ( u_char *p ) {
#define DGM_POSITIVE_RES 0x15
#define DGM_NEGATIVE_RES 0x16
void AliasHandleUdpNbt(
int AliasHandleUdpNbt(
struct ip *pip, /* IP packet to examine/patch */
struct alias_link *link,
struct in_addr *alias_address,
u_short alias_port )
{
u_short alias_port
) {
struct udphdr * uh;
NbtDataHeader *ndh;
u_char *p;
u_char *p = NULL;
char *pmax;
/* Calculate data length of UDP packet */
uh = (struct udphdr *) ((char *) pip + (pip->ip_hl << 2));
pmax = (char *)uh + ntohs( uh->uh_ulen );
ndh = (NbtDataHeader *)((char *)uh + (sizeof (struct udphdr)));
if ((char *)(ndh + 1) > pmax)
return(-1);
#ifdef DEBUG
printf("\nType=%02x,", ndh->type );
#endif
@ -215,8 +233,8 @@ void AliasHandleUdpNbt(
case DGM_DIRECT_GROUP:
case DGM_BROADCAST:
p = (u_char *)ndh + 14;
p = AliasHandleName ( p ); /* Source Name */
p = AliasHandleName ( p ); /* Destination Name */
p = AliasHandleName ( p, pmax ); /* Source Name */
p = AliasHandleName ( p, pmax ); /* Destination Name */
break;
case DGM_ERROR:
p = (u_char *)ndh + 11;
@ -225,9 +243,11 @@ void AliasHandleUdpNbt(
case DGM_POSITIVE_RES:
case DGM_NEGATIVE_RES:
p = (u_char *)ndh + 10;
p = AliasHandleName ( p ); /* Destination Name */
p = AliasHandleName ( p, pmax ); /* Destination Name */
break;
}
if (p == NULL || (char *)p > pmax)
p = NULL;
#ifdef DEBUG
printf("%s:%d-->", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port) );
#endif
@ -251,6 +271,7 @@ void AliasHandleUdpNbt(
printf("%s:%d\n", inet_ntoa(ndh->source_ip), ntohs(ndh->source_port) );
fflush(stdout);
#endif
return((p == NULL) ? -1 : 0);
}
/* Question Section */
#define QS_TYPE_NB 0x0020
@ -261,14 +282,22 @@ typedef struct {
u_short class; /* The class of Request */
} NBTNsQuestion;
u_char *AliasHandleQuestion(u_short count,
u_char *
AliasHandleQuestion(
u_short count,
NBTNsQuestion *q,
char *pmax,
NBTArguments *nbtarg)
{
while ( count != 0 ) {
/* Name Filed */
q = (NBTNsQuestion *)AliasHandleName((u_char *)q );
q = (NBTNsQuestion *)AliasHandleName((u_char *)q, pmax);
if (q == NULL || (char *)(q + 1) > pmax) {
q = NULL;
break;
}
/* Type and Class filed */
switch ( ntohs(q->type) ) {
@ -308,12 +337,17 @@ typedef struct {
struct in_addr addr;
} NBTNsRNB;
u_char *AliasHandleResourceNB( NBTNsResource *q,
u_char *
AliasHandleResourceNB(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsRNB *nb;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Check out a length */
bcount = ntohs(q->rdlen);
@ -325,7 +359,11 @@ u_char *AliasHandleResourceNB( NBTNsResource *q,
printf("NB rec[%s", inet_ntoa(nbtarg->oldaddr));
printf("->%s, %dbytes] ",inet_ntoa(nbtarg->newaddr ), bcount);
#endif
while ( bcount != 0 ) {
while ( nb != NULL && bcount != 0 ) {
if ((char *)(nb + 1) > pmax) {
nb = NULL;
break;
}
#ifdef DEBUG
printf("<%s>", inet_ntoa(nb->addr) );
#endif
@ -356,6 +394,9 @@ u_char *AliasHandleResourceNB( NBTNsResource *q,
nb=(NBTNsRNB *)((u_char *)nb + SizeOfNsRNB);
bcount -= SizeOfNsRNB;
}
if (nb == NULL || (char *)(nb + 1) > pmax) {
nb = NULL;
}
return ((u_char *)nb);
}
@ -365,12 +406,18 @@ typedef struct {
struct in_addr addr;
} NBTNsResourceA;
u_char *AliasHandleResourceA( NBTNsResource *q,
u_char *
AliasHandleResourceA(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsResourceA *a;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Forward to Resource A position */
a = (NBTNsResourceA *)( (u_char *)q + sizeof(NBTNsResource) );
@ -383,6 +430,8 @@ u_char *AliasHandleResourceA( NBTNsResource *q,
printf("->%s]",inet_ntoa(nbtarg->newaddr ));
#endif
while ( bcount != 0 ) {
if (a == NULL || (char *)(a + 1) > pmax)
return(NULL);
#ifdef DEBUG
printf("..%s", inet_ntoa(a->addr) );
#endif
@ -405,6 +454,8 @@ u_char *AliasHandleResourceA( NBTNsResource *q,
a++; /*XXXX*/
bcount -= SizeOfResourceA;
}
if (a == NULL || (char *)(a + 1) > pmax)
a = NULL;
return ((u_char *)a);
}
@ -412,12 +463,18 @@ typedef struct {
u_short opcode:4, flags:8, resv:4;
} NBTNsResourceNULL;
u_char *AliasHandleResourceNULL( NBTNsResource *q,
u_char *
AliasHandleResourceNULL(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsResourceNULL *n;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Forward to Resource NULL position */
n = (NBTNsResourceNULL *)( (u_char *)q + sizeof(NBTNsResource) );
@ -426,19 +483,31 @@ u_char *AliasHandleResourceNULL( NBTNsResource *q,
/* Processing all in_addr array */
while ( bcount != 0 ) {
if ((char *)(n + 1) > pmax) {
n = NULL;
break;
}
n++;
bcount -= sizeof(NBTNsResourceNULL);
}
if ((char *)(n + 1) > pmax)
n = NULL;
return ((u_char *)n);
}
u_char *AliasHandleResourceNS( NBTNsResource *q,
u_char *
AliasHandleResourceNS(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsResourceNULL *n;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Forward to Resource NULL position */
n = (NBTNsResourceNULL *)( (u_char *)q + sizeof(NBTNsResource) );
@ -446,8 +515,11 @@ u_char *AliasHandleResourceNS( NBTNsResource *q,
bcount = ntohs(q->rdlen);
/* Resource Record Name Filed */
q = (NBTNsResource *)AliasHandleName( (u_char *)n ); /* XXX */
q = (NBTNsResource *)AliasHandleName( (u_char *)n, pmax ); /* XXX */
if (q == NULL || (char *)((u_char *)n + bcount) > pmax)
return(NULL);
else
return ((u_char *)n + bcount);
}
@ -455,28 +527,44 @@ typedef struct {
u_short numnames;
} NBTNsResourceNBSTAT;
u_char *AliasHandleResourceNBSTAT( NBTNsResource *q,
u_char *
AliasHandleResourceNBSTAT(
NBTNsResource *q,
char *pmax,
NBTArguments *nbtarg)
{
NBTNsResourceNBSTAT *n;
u_short bcount;
if (q == NULL || (char *)(q + 1) > pmax)
return(NULL);
/* Forward to Resource NBSTAT position */
n = (NBTNsResourceNBSTAT *)( (u_char *)q + sizeof(NBTNsResource) );
/* Check out of length */
bcount = ntohs(q->rdlen);
if (q == NULL || (char *)((u_char *)n + bcount) > pmax)
return(NULL);
else
return ((u_char *)n + bcount);
}
u_char *AliasHandleResource(u_short count,
u_char *
AliasHandleResource(
u_short count,
NBTNsResource *q,
NBTArguments *nbtarg)
char *pmax,
NBTArguments
*nbtarg)
{
while ( count != 0 ) {
/* Resource Record Name Filed */
q = (NBTNsResource *)AliasHandleName( (u_char *)q );
q = (NBTNsResource *)AliasHandleName( (u_char *)q, pmax );
if (q == NULL || (char *)(q + 1) > pmax)
break;
#ifdef DEBUG
printf("type=%02x, count=%d\n", ntohs(q->type), count );
#endif
@ -484,22 +572,45 @@ u_char *AliasHandleResource(u_short count,
/* Type and Class filed */
switch ( ntohs(q->type) ) {
case RR_TYPE_NB:
q = (NBTNsResource *)AliasHandleResourceNB( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceNB(
q,
pmax,
nbtarg
);
break;
case RR_TYPE_A:
q = (NBTNsResource *)AliasHandleResourceA( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceA(
q,
pmax,
nbtarg
);
break;
case RR_TYPE_NS:
q = (NBTNsResource *)AliasHandleResourceNS( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceNS(
q,
pmax,
nbtarg
);
break;
case RR_TYPE_NULL:
q = (NBTNsResource *)AliasHandleResourceNULL( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceNULL(
q,
pmax,
nbtarg
);
break;
case RR_TYPE_NBSTAT:
q = (NBTNsResource *)AliasHandleResourceNBSTAT( q, nbtarg );
q = (NBTNsResource *)AliasHandleResourceNBSTAT(
q,
pmax,
nbtarg
);
break;
default: printf("\nUnknown Type of Resource %0x\n",
ntohs(q->type) );
default:
printf(
"\nUnknown Type of Resource %0x\n",
ntohs(q->type)
);
break;
}
count--;
@ -508,7 +619,7 @@ u_char *AliasHandleResource(u_short count,
return ((u_char *)q);
}
void AliasHandleUdpNbtNS(
int AliasHandleUdpNbtNS(
struct ip *pip, /* IP packet to examine/patch */
struct alias_link *link,
struct in_addr *alias_address,
@ -518,8 +629,8 @@ void AliasHandleUdpNbtNS(
{
struct udphdr * uh;
NbtNSHeader * nsh;
u_short dlen;
u_char * p;
char *pmax;
NBTArguments nbtarg;
/* Set up Common Parameter */
@ -531,12 +642,16 @@ void AliasHandleUdpNbtNS(
/* Calculate data length of UDP packet */
uh = (struct udphdr *) ((char *) pip + (pip->ip_hl << 2));
nbtarg.uh_sum = &(uh->uh_sum);
dlen = ntohs( uh->uh_ulen );
nsh = (NbtNSHeader *)((char *)uh + (sizeof(struct udphdr)));
p = (u_char *)(nsh + 1);
pmax = (char *)uh + ntohs( uh->uh_ulen );
if ((char *)(nsh + 1) > pmax)
return(-1);
#ifdef DEBUG
printf(" [%s] ID=%02x, op=%01x, flag=%02x, rcode=%01x, qd=%04x, an=%04x, ns=%04x, ar=%04x, [%d]-->",
printf(" [%s] ID=%02x, op=%01x, flag=%02x, rcode=%01x, qd=%04x"
", an=%04x, ns=%04x, ar=%04x, [%d]-->",
nsh->dir ? "Response": "Request",
nsh->nametrid,
nsh->opcode,
@ -546,31 +661,53 @@ void AliasHandleUdpNbtNS(
ntohs(nsh->ancount),
ntohs(nsh->nscount),
ntohs(nsh->arcount),
(u_char *)p -(u_char *)nsh);
(u_char *)p -(u_char *)nsh
);
#endif
/* Question Entries */
if (ntohs(nsh->qdcount) !=0 ) {
p = AliasHandleQuestion(ntohs(nsh->qdcount), (NBTNsQuestion *)p, &nbtarg );
p = AliasHandleQuestion(
ntohs(nsh->qdcount),
(NBTNsQuestion *)p,
pmax,
&nbtarg
);
}
/* Answer Resource Records */
if (ntohs(nsh->ancount) !=0 ) {
p = AliasHandleResource(ntohs(nsh->ancount), (NBTNsResource *)p, &nbtarg );
p = AliasHandleResource(
ntohs(nsh->ancount),
(NBTNsResource *)p,
pmax,
&nbtarg
);
}
/* Authority Resource Recodrs */
if (ntohs(nsh->nscount) !=0 ) {
p = AliasHandleResource(ntohs(nsh->nscount), (NBTNsResource *)p, &nbtarg );
p = AliasHandleResource(
ntohs(nsh->nscount),
(NBTNsResource *)p,
pmax,
&nbtarg
);
}
/* Additional Resource Recodrs */
if (ntohs(nsh->arcount) !=0 ) {
p = AliasHandleResource(ntohs(nsh->arcount), (NBTNsResource *)p, &nbtarg );
p = AliasHandleResource(
ntohs(nsh->arcount),
(NBTNsResource *)p,
pmax,
&nbtarg
);
}
#ifdef DEBUG
PrintRcode(nsh->rcode);
#endif
return;
return ((p == NULL) ? -1 : 0);
}