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resolv: Move ns_name_pack into its own file and into libc

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And reformat to GNU style, and eliminate the labellen function.

The symbol was moved using scripts/move-symbol-to-libc.py.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
This commit is contained in:
Florian Weimer
2021-07-19 07:55:27 +02:00
parent 276e9822b3
commit 7ed1ac6da3
69 changed files with 274 additions and 227 deletions
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194
resolv/ns_name.c
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@@ -31,9 +31,6 @@
/* Forward. */
static int dn_find(const u_char *, const u_char *,
const u_char * const *,
const u_char * const *);
static int labellen(const u_char *);
/* Public. */
@@ -92,118 +89,6 @@ ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz)
return (dn - dst);
}
/*%
* Pack domain name 'domain' into 'comp_dn'.
*
* return:
*\li Size of the compressed name, or -1.
*
* notes:
*\li 'dnptrs' is an array of pointers to previous compressed names.
*\li dnptrs[0] is a pointer to the beginning of the message. The array
* ends with NULL.
*\li 'lastdnptr' is a pointer to the end of the array pointed to
* by 'dnptrs'.
*
* Side effects:
*\li 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
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; /*%< end of list to search */
}
} else
msg = NULL;
/* make sure the domain we are about to add is legal */
l = 0;
do {
int l0;
n = *srcp;
if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
__set_errno (EMSGSIZE);
return (-1);
}
if ((l0 = labellen(srcp)) < 0) {
__set_errno (EINVAL);
return(-1);
}
l += l0 + 1;
if (l > MAXCDNAME) {
__set_errno (EMSGSIZE);
return (-1);
}
srcp += l0 + 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 && first) {
*cpp++ = dstp;
*cpp = NULL;
first = 0;
}
}
/* copy label to buffer */
if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
/* Should not happen. */
goto cleanup;
}
n = labellen(srcp);
if (n + 1 > eob - dstp) {
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;
__set_errno (EMSGSIZE);
return (-1);
}
return (dstp - dst);
}
libresolv_hidden_def (ns_name_pack)
/*%
* Compress a domain name into wire format, using compression pointers.
*
@@ -250,85 +135,6 @@ ns_name_rollback(const u_char *src, const u_char **dnptrs,
/* Private. */
/*%
* Thinking in noninternationalized USASCII (per the DNS spec),
* convert this character to lower case if it's upper case.
*/
static int
mklower(int ch) {
if (ch >= 0x41 && ch <= 0x5A)
return (ch + 0x20);
return (ch);
}
/*%
* Search for the counted-label name in an array of compressed names.
*
* return:
*\li offset from msg if found, or -1.
*
* notes:
*\li dnptrs is the pointer to the first name on the list,
*\li not the pointer to the start of the message.
*/
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;
/*
* terminate search on:
* root label
* compression pointer
* unusable offset
*/
while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 &&
(sp - msg) < 0x4000) {
dn = domain;
cp = sp;
while ((n = *cp++) != 0) {
/*
* check for indirection
*/
switch (n & NS_CMPRSFLGS) {
case 0: /*%< normal case, n == len */
n = labellen(cp - 1); /*%< XXX */
if (n != *dn++)
goto next;
for ((void)NULL; n > 0; n--)
if (mklower(*dn++) !=
mklower(*cp++))
goto next;
/* Is next root for both ? */
if (*dn == '\0' && *cp == '\0')
return (sp - msg);
if (*dn)
continue;
goto next;
case NS_CMPRSFLGS: /*%< indirection */
cp = msg + (((n & 0x3f) << 8) | *cp);
break;
default: /*%< illegal type */
__set_errno (EMSGSIZE);
return (-1);
}
}
next: ;
sp += *sp + 1;
}
}
__set_errno (ENOENT);
return (-1);
}
/* Return the length of the encoded label starting at LP, or -1 for
compression references and extended label types. */
static int