static int ns_name_pack(const unsigned char *src, unsigned char *dst,
int dstsiz, unsigned char **dnptrs,
unsigned char **lastdnptr)
{
unsigned char *dstp;
unsigned char **cpp, **lpp, *eob, *msg;
unsigned char *srcp;
int n, l, first = 1;
srcp = (unsigned char *) src;
dstp = dst;
eob = dstp + dstsiz;
lpp = cpp = NULL;
if (dnptrs != NULL) {
if ((msg = *dnptrs++) != NULL) {
for (cpp = dnptrs; *cpp != NULL; cpp++);
lpp = cpp;
}
} else {
msg = NULL;
}
// Make sure the domain we are about to add is legal
l = 0;
do {
n = *srcp;
if ((n & NS_CMPRSFLGS) != 0) {
errno = EMSGSIZE;
return -1;
}
l += n + 1;
if (l > NS_MAXCDNAME) {
errno = EMSGSIZE;
return -1;
}
srcp += n + 1;
} while (n != 0);
// From here on we need to reset compression pointer array on error
srcp = (unsigned char *) src;
do {
// Look to see if we can use pointers
n = *srcp;
if (n != 0 && msg != NULL) {
l = dn_find(srcp, msg, dnptrs, lpp);
if (l >= 0) {
if (dstp + 1 >= eob)
goto cleanup;
*dstp++ = (l >> 8) | NS_CMPRSFLGS;
*dstp++ = l % 256;
return dstp - dst;
}
// Not found, save it
if (lastdnptr != NULL && cpp < lastdnptr - 1
&& (dstp - msg) < 0x4000 && first) {
*cpp++ = dstp;
*cpp = NULL;
first = 0;
}
}
// Copy label to buffer
if (n & NS_CMPRSFLGS)
goto cleanup;
if (dstp + 1 + n >= eob)
goto cleanup;
memcpy(dstp, srcp, n + 1);
srcp += n + 1;
dstp += n + 1;
} while (n != 0);
/*
* MRns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr)
* Pack domain name 'domain' into 'comp_dn'.
* return:
* Size of the compressed name, or -1.
* notes:
* 'dnptrs' is an array of pointers to previous compressed names.
* dnptrs[0] is a pointer to the beginning of the message. The array
* ends with NULL.
* 'lastdnptr' is a pointer to the end of the array pointed to
* by 'dnptrs'.
* Side effects:
* The list of pointers in dnptrs is updated for labels inserted into
* the message as we compress the name. If 'dnptr' is NULL, we don't
* try to compress names. If 'lastdnptr' is NULL, we don't update the
* list.
*/
int
MRns_name_pack(const u_char *src, u_char *dst, unsigned dstsiz,
const u_char **dnptrs, const u_char **lastdnptr)
{
u_char *dstp;
const u_char **cpp, **lpp, *eob, *msg;
const u_char *srcp;
unsigned n;
int l;
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; /* end of list to search */
}
} else
msg = NULL;
/* make sure the domain we are about to add is legal */
l = 0;
do {
n = *srcp;
if ((n & NS_CMPRSFLGS) != 0) {
errno = EMSGSIZE;
return (-1);
}
l += n + 1;
if (l > MAXCDNAME) {
errno = EMSGSIZE;
return (-1);
}
srcp += n + 1;
} while (n != 0);
/* from here on we need to reset compression pointer array on error */
srcp = src;
do {
/* Look to see if we can use pointers. */
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);
}
/* Not found, save it. */
if (lastdnptr != NULL && cpp < lastdnptr - 1 &&
(dstp - msg) < 0x4000) {
*cpp++ = dstp;
*cpp = NULL;
}
}
/* copy label to buffer */
if (n & NS_CMPRSFLGS) { /* Should not happen. */
goto cleanup;
}
if (dstp + 1 + n >= eob) {
goto cleanup;
}
memcpy(dstp, srcp, n + 1);
srcp += n + 1;
dstp += n + 1;
} while (n != 0);
/*
* Compress domain name 'exp_dn' into 'comp_dn'.
* Return the size of the compressed name or -1.
* 'length' is the size of the array pointed to by 'comp_dn'.
* 'dnptrs' is a list of pointers to previous compressed names. dnptrs[0]
* is a pointer to the beginning of the message. The list ends with NULL.
* 'lastdnptr' is a pointer to the end of the arrary pointed to
* by 'dnptrs'. Side effect is to update the list of pointers for
* labels inserted into the message as we compress the name.
* If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr'
* is NULL, we don't update the list.
*/
int
dn_comp(const char *exp_dn, u_char *comp_dn, int length, u_char **dnptrs,
u_char **lastdnptr)
{
u_char *cp, *dn;
int c, l;
u_char **cpp, **lpp, *sp, *eob;
u_char *msg;
dn = (u_char *)exp_dn;
cp = comp_dn;
eob = cp + length;
lpp = cpp = NULL;
if (dnptrs != NULL) {
if ((msg = *dnptrs++) != NULL) {
for (cpp = dnptrs; *cpp != NULL; cpp++)
;
lpp = cpp; /* end of list to search */
}
} else
msg = NULL;
for (c = *dn++; c != '\0'; ) {
/* look to see if we can use pointers */
if (msg != NULL) {
if ((l = dn_find(dn-1, msg, dnptrs, lpp)) >= 0) {
if (cp+1 >= eob)
return (-1);
*cp++ = (l >> 8) | INDIR_MASK;
*cp++ = l % 256;
return (cp - comp_dn);
}
/* not found, save it */
if (lastdnptr != NULL && cpp < lastdnptr-1) {
*cpp++ = cp;
*cpp = NULL;
}
}
sp = cp++; /* save ptr to length byte */
do {
if (c == '.') {
c = *dn++;
break;
}
if (c == '\\') {
if ((c = *dn++) == '\0')
break;
}
if (cp >= eob) {
if (msg != NULL)
*lpp = NULL;
return (-1);
}
*cp++ = c;
} while ((c = *dn++) != '\0');
/* catch trailing '.'s but not '..' */
if ((l = cp - sp - 1) == 0 && c == '\0') {
cp--;
break;
}
if (l <= 0 || l > MAXLABEL) {
if (msg != NULL)
*lpp = NULL;
return (-1);
}
*sp = l;
}
if (cp >= eob) {
if (msg != NULL)
*lpp = NULL;
return (-1);
}
*cp++ = '\0';
return (cp - comp_dn);
}