#ifndef lint
static const char rcsid[] = "$Id: ns_name.c,v 1.3.2.4.4.2 2004/05/04 03:27:47 marka Exp $";
#endif
#include "port_before.h"
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <errno.h>
#include <resolv.h>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <limits.h>
#include "port_after.h"
#ifdef SPRINTF_CHAR
# define SPRINTF(x) strlen(sprintfx)
#else
# define SPRINTF(x) ((size_t)sprintf x)
#endif
#define NS_TYPE_ELT 0x40
#define DNS_LABELTYPE_BITSTRING 0x41
static const char digits[] = "0123456789";
static const char digitvalue[256] = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
};
static int special(int);
static int printable(int);
static int dn_find(const u_char *, const u_char *,
const u_char * const *,
const u_char * const *);
static int encode_bitsring(const char **, const char *,
unsigned char **, unsigned char **,
unsigned const char *);
static int labellen(const u_char *);
static int decode_bitstring(const unsigned char **,
char *, const char *);
int
ns_name_ntop(const u_char *src, char *dst, size_t dstsiz)
{
const u_char *cp;
char *dn, *eom;
u_char c;
u_int n;
int l;
cp = src;
dn = dst;
eom = dst + dstsiz;
while ((n = *cp++) != 0) {
if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
errno = EMSGSIZE;
return (-1);
}
if (dn != dst) {
if (dn >= eom) {
errno = EMSGSIZE;
return (-1);
}
*dn++ = '.';
}
if ((l = labellen(cp - 1)) < 0) {
errno = EMSGSIZE;
return(-1);
}
if (dn + l >= eom) {
errno = EMSGSIZE;
return (-1);
}
if ((n & NS_CMPRSFLGS) == NS_TYPE_ELT) {
int m;
if (n != DNS_LABELTYPE_BITSTRING) {
errno = EINVAL;
return(-1);
}
if ((m = decode_bitstring(&cp, dn, eom)) < 0)
{
errno = EMSGSIZE;
return(-1);
}
dn += m;
continue;
}
for ((void)NULL; l > 0; l--) {
c = *cp++;
if (special(c)) {
if (dn + 1 >= eom) {
errno = EMSGSIZE;
return (-1);
}
*dn++ = '\\';
*dn++ = (char)c;
} else if (!printable(c)) {
if (dn + 3 >= eom) {
errno = EMSGSIZE;
return (-1);
}
*dn++ = '\\';
*dn++ = digits[c / 100];
*dn++ = digits[(c % 100) / 10];
*dn++ = digits[c % 10];
} else {
if (dn >= eom) {
errno = EMSGSIZE;
return (-1);
}
*dn++ = (char)c;
}
}
}
if (dn == dst) {
if (dn >= eom) {
errno = EMSGSIZE;
return (-1);
}
*dn++ = '.';
}
if (dn >= eom) {
errno = EMSGSIZE;
return (-1);
}
*dn++ = '\0';
return (dn - dst);
}
int
ns_name_pton(const char *src, u_char *dst, size_t dstsiz)
{
u_char *label, *bp, *eom;
int c, n, escaped, e = 0;
char *cp;
escaped = 0;
bp = dst;
eom = dst + dstsiz;
label = bp++;
while ((c = *src++) != 0) {
if (escaped) {
if (c == '[') {
if ((cp = strchr(src, ']')) == NULL) {
errno = EINVAL;
return(-1);
}
if ((e = encode_bitsring(&src, cp + 2,
&label, &bp, eom))
!= 0) {
errno = e;
return(-1);
}
escaped = 0;
label = bp++;
if ((c = *src++) == 0)
goto done;
else if (c != '.') {
errno = EINVAL;
return(-1);
}
continue;
}
else if ((cp = strchr(digits, c)) != NULL) {
n = (cp - digits) * 100;
if ((c = *src++) == 0 ||
(cp = strchr(digits, c)) == NULL) {
errno = EMSGSIZE;
return (-1);
}
n += (cp - digits) * 10;
if ((c = *src++) == 0 ||
(cp = strchr(digits, c)) == NULL) {
errno = EMSGSIZE;
return (-1);
}
n += (cp - digits);
if (n > 255) {
errno = EMSGSIZE;
return (-1);
}
c = n;
}
escaped = 0;
} else if (c == '\\') {
escaped = 1;
continue;
} else if (c == '.') {
c = (bp - label - 1);
if ((c & NS_CMPRSFLGS) != 0) {
errno = EMSGSIZE;
return (-1);
}
if (label >= eom) {
errno = EMSGSIZE;
return (-1);
}
*label = c;
if (*src == '\0') {
if (c != 0) {
if (bp >= eom) {
errno = EMSGSIZE;
return (-1);
}
*bp++ = '\0';
}
if ((bp - dst) > MAXCDNAME) {
errno = EMSGSIZE;
return (-1);
}
return (1);
}
if (c == 0 || *src == '.') {
errno = EMSGSIZE;
return (-1);
}
label = bp++;
continue;
}
if (bp >= eom) {
errno = EMSGSIZE;
return (-1);
}
*bp++ = (u_char)c;
}
c = (bp - label - 1);
if ((c & NS_CMPRSFLGS) != 0) {
errno = EMSGSIZE;
return (-1);
}
done:
if (label >= eom) {
errno = EMSGSIZE;
return (-1);
}
*label = c;
if (c != 0) {
if (bp >= eom) {
errno = EMSGSIZE;
return (-1);
}
*bp++ = 0;
}
if ((bp - dst) > MAXCDNAME) {
errno = EMSGSIZE;
return (-1);
}
return (0);
}
int
ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz)
{
const u_char *cp;
u_char *dn, *eom;
u_char c;
u_int n;
int l;
cp = src;
dn = dst;
eom = dst + dstsiz;
if (dn >= eom) {
errno = EMSGSIZE;
return (-1);
}
while ((n = *cp++) != 0) {
if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
errno = EMSGSIZE;
return (-1);
}
*dn++ = n;
if ((l = labellen(cp - 1)) < 0) {
errno = EMSGSIZE;
return (-1);
}
if (dn + l >= eom) {
errno = EMSGSIZE;
return (-1);
}
for ((void)NULL; l > 0; l--) {
c = *cp++;
if (isupper(c))
*dn++ = tolower(c);
else
*dn++ = c;
}
}
*dn++ = '\0';
return (dn - dst);
}
int
ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
u_char *dst, size_t dstsiz)
{
const u_char *srcp, *dstlim;
u_char *dstp;
int n, len, checked, l;
len = -1;
checked = 0;
dstp = dst;
srcp = src;
dstlim = dst + dstsiz;
if (srcp < msg || srcp >= eom) {
errno = EMSGSIZE;
return (-1);
}
while ((n = *srcp++) != 0) {
switch (n & NS_CMPRSFLGS) {
case 0:
case NS_TYPE_ELT:
if ((l = labellen(srcp - 1)) < 0) {
errno = EMSGSIZE;
return(-1);
}
if (dstp + l + 1 >= dstlim || srcp + l >= eom) {
errno = EMSGSIZE;
return (-1);
}
checked += l + 1;
*dstp++ = n;
memcpy(dstp, srcp, l);
dstp += l;
srcp += l;
break;
case NS_CMPRSFLGS:
if (srcp >= eom) {
errno = EMSGSIZE;
return (-1);
}
if (len < 0)
len = srcp - src + 1;
srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
if (srcp < msg || srcp >= eom) {
errno = EMSGSIZE;
return (-1);
}
checked += 2;
if (checked >= eom - msg) {
errno = EMSGSIZE;
return (-1);
}
break;
default:
errno = EMSGSIZE;
return (-1);
}
}
*dstp = '\0';
if (len < 0)
len = srcp - src;
return (len);
}
int
ns_name_pack(const u_char *src, u_char *dst, int dstsiz,
const u_char **dnptrs, const u_char **lastdnptr)
{
u_char *dstp;
const u_char **cpp, **lpp, *eob, *msg;
const u_char *srcp;
int n, l, first = 1;
srcp = src;
dstp = dst;
eob = dstp + dstsiz;
lpp = cpp = NULL;
if (dnptrs != NULL) {
if ((msg = *dnptrs++) != NULL) {
for (cpp = dnptrs; *cpp != NULL; cpp++)
(void)NULL;
lpp = cpp;
}
} else
msg = NULL;
l = 0;
do {
int l0;
n = *srcp;
if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
errno = EMSGSIZE;
return (-1);
}
if ((l0 = labellen(srcp)) < 0) {
errno = EINVAL;
return(-1);
}
l += l0 + 1;
if (l > MAXCDNAME) {
errno = EMSGSIZE;
return (-1);
}
srcp += l0 + 1;
} while (n != 0);
srcp = src;
do {
n = *srcp;
if (n != 0 && msg != NULL) {
l = dn_find(srcp, msg, (const u_char * const *)dnptrs,
(const u_char * const *)lpp);
if (l >= 0) {
if (dstp + 1 >= eob) {
goto cleanup;
}
*dstp++ = (l >> 8) | NS_CMPRSFLGS;
*dstp++ = l % 256;
return (dstp - dst);
}
if (lastdnptr != NULL && cpp < lastdnptr - 1 &&
(dstp - msg) < 0x4000 && first) {
*cpp++ = dstp;
*cpp = NULL;
first = 0;
}
}
if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
goto cleanup;
}
n = labellen(srcp);
if (dstp + 1 + n >= eob) {
goto cleanup;
}
memcpy(dstp, srcp, n + 1);
srcp += n + 1;
dstp += n + 1;
} while (n != 0);
if (dstp > eob) {
cleanup:
if (msg != NULL)
*lpp = NULL;
errno = EMSGSIZE;
return (-1);
}
return (dstp - dst);
}
int
ns_name_uncompress(const u_char *msg, const u_char *eom, const u_char *src,
char *dst, size_t dstsiz)
{
u_char tmp[NS_MAXCDNAME];
int n;
if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
return (-1);
if (ns_name_ntop(tmp, dst, dstsiz) == -1)
return (-1);
return (n);
}
int
ns_name_compress(const char *src, u_char *dst, size_t dstsiz,
const u_char **dnptrs, const u_char **lastdnptr)
{
u_char tmp[NS_MAXCDNAME];
if (ns_name_pton(src, tmp, sizeof tmp) == -1)
return (-1);
return (ns_name_pack(tmp, dst, dstsiz, dnptrs, lastdnptr));
}
void
ns_name_rollback(const u_char *src, const u_char **dnptrs,
const u_char **lastdnptr)
{
while (dnptrs < lastdnptr && *dnptrs != NULL) {
if (*dnptrs >= src) {
*dnptrs = NULL;
break;
}
dnptrs++;
}
}
int
ns_name_skip(const u_char **ptrptr, const u_char *eom)
{
const u_char *cp;
u_int n;
int l;
cp = *ptrptr;
while (cp < eom && (n = *cp++) != 0) {
switch (n & NS_CMPRSFLGS) {
case 0:
cp += n;
continue;
case NS_TYPE_ELT:
if ((l = labellen(cp - 1)) < 0) {
errno = EMSGSIZE;
return(-1);
}
cp += l;
continue;
case NS_CMPRSFLGS:
cp++;
break;
default:
errno = EMSGSIZE;
return (-1);
}
break;
}
if (cp > eom) {
errno = EMSGSIZE;
return (-1);
}
*ptrptr = cp;
return (0);
}
static int
special(int ch) {
switch (ch) {
case 0x22:
case 0x2E:
case 0x3B:
case 0x5C:
case 0x28:
case 0x29:
case 0x40:
case 0x24:
return (1);
default:
return (0);
}
}
static int
printable(int ch) {
return (ch > 0x20 && ch < 0x7f);
}
static int
mklower(int ch) {
if (ch >= 0x41 && ch <= 0x5A)
return (ch + 0x20);
return (ch);
}
static int
dn_find(const u_char *domain, const u_char *msg,
const u_char * const *dnptrs,
const u_char * const *lastdnptr)
{
const u_char *dn, *cp, *sp;
const u_char * const *cpp;
u_int n;
for (cpp = dnptrs; cpp < lastdnptr; cpp++) {
sp = *cpp;
while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 &&
(sp - msg) < 0x4000) {
dn = domain;
cp = sp;
while ((n = *cp++) != 0) {
switch (n & NS_CMPRSFLGS) {
case 0:
n = labellen(cp - 1);
if (n != *dn++)
goto next;
for ((void)NULL; n > 0; n--)
if (mklower(*dn++) !=
mklower(*cp++))
goto next;
if (*dn == '\0' && *cp == '\0')
return (sp - msg);
if (*dn)
continue;
goto next;
case NS_CMPRSFLGS:
cp = msg + (((n & 0x3f) << 8) | *cp);
break;
default:
errno = EMSGSIZE;
return (-1);
}
}
next: ;
sp += *sp + 1;
}
}
errno = ENOENT;
return (-1);
}
static int
decode_bitstring(const unsigned char **cpp, char *dn, const char *eom)
{
const unsigned char *cp = *cpp;
char *beg = dn, tc;
int b, blen, plen, i;
if ((blen = (*cp & 0xff)) == 0)
blen = 256;
plen = (blen + 3) / 4;
plen += sizeof("\\[x/]") + (blen > 99 ? 3 : (blen > 9) ? 2 : 1);
if (dn + plen >= eom)
return(-1);
cp++;
i = SPRINTF((dn, "\\[x"));
if (i < 0)
return (-1);
dn += i;
for (b = blen; b > 7; b -= 8, cp++) {
i = SPRINTF((dn, "%02x", *cp & 0xff));
if (i < 0)
return (-1);
dn += i;
}
if (b > 4) {
tc = *cp++;
i = SPRINTF((dn, "%02x", tc & (0xff << (8 - b))));
if (i < 0)
return (-1);
dn += i;
} else if (b > 0) {
tc = *cp++;
i = SPRINTF((dn, "%1x",
((tc >> 4) & 0x0f) & (0x0f << (4 - b))));
if (i < 0)
return (-1);
dn += i;
}
i = SPRINTF((dn, "/%d]", blen));
if (i < 0)
return (-1);
dn += i;
*cpp = cp;
return(dn - beg);
}
static int
encode_bitsring(const char **bp, const char *end, unsigned char **labelp,
unsigned char ** dst, unsigned const char *eom)
{
int afterslash = 0;
const char *cp = *bp;
unsigned char *tp;
char c;
const char *beg_blen;
char *end_blen = NULL;
int value = 0, count = 0, tbcount = 0, blen = 0;
beg_blen = end_blen = NULL;
if (end - cp < 2)
return(EINVAL);
if (*cp++ != 'x')
return(EINVAL);
if (!isxdigit((*cp) & 0xff))
return(EINVAL);
for (tp = *dst + 1; cp < end && tp < eom; cp++) {
switch((c = *cp)) {
case ']':
if (afterslash) {
if (beg_blen == NULL)
return(EINVAL);
blen = (int)strtol(beg_blen, &end_blen, 10);
if (*end_blen != ']')
return(EINVAL);
}
if (count)
*tp++ = ((value << 4) & 0xff);
cp++;
goto done;
case '/':
afterslash = 1;
break;
default:
if (afterslash) {
if (!isdigit(c&0xff))
return(EINVAL);
if (beg_blen == NULL) {
if (c == '0') {
return(EINVAL);
}
beg_blen = cp;
}
} else {
if (!isxdigit(c&0xff))
return(EINVAL);
value <<= 4;
value += digitvalue[(int)c];
count += 4;
tbcount += 4;
if (tbcount > 256)
return(EINVAL);
if (count == 8) {
*tp++ = value;
count = 0;
}
}
break;
}
}
done:
if (cp >= end || tp >= eom)
return(EMSGSIZE);
if (blen > 0) {
int traillen;
if (((blen + 3) & ~3) != tbcount)
return(EINVAL);
traillen = tbcount - blen;
if (((value << (8 - traillen)) & 0xff) != 0)
return(EINVAL);
}
else
blen = tbcount;
if (blen == 256)
blen = 0;
**labelp = DNS_LABELTYPE_BITSTRING;
**dst = blen;
*bp = cp;
*dst = tp;
return(0);
}
static int
labellen(const u_char *lp)
{
int bitlen;
u_char l = *lp;
if ((l & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
return(-1);
}
if ((l & NS_CMPRSFLGS) == NS_TYPE_ELT) {
if (l == DNS_LABELTYPE_BITSTRING) {
if ((bitlen = *(lp + 1)) == 0)
bitlen = 256;
return((bitlen + 7 ) / 8 + 1);
}
return(-1);
}
return(l);
}