762a2b2d34
But only as an internal symbol, __libc_ns_samename. The libresolv ABI is preserved. This is because the function is deprecated, and it does not make sense to add new symbol versions for deprecated functions. Also reformat the implementation to GNU style. Reviewed-by: Carlos O'Donell <carlos@redhat.com> Tested-by: Carlos O'Donell <carlos@redhat.com>
148 lines
3.6 KiB
C
148 lines
3.6 KiB
C
/*
|
|
* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
|
|
* Copyright (c) 1995,1999 by Internet Software Consortium.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
|
|
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
|
|
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
|
|
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
|
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
|
|
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
|
|
* SOFTWARE.
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
#include <arpa/nameser.h>
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
|
|
/*%
|
|
* Check whether a name belongs to a domain.
|
|
*
|
|
* Inputs:
|
|
*\li a - the domain whose ancestry is being verified
|
|
*\li b - the potential ancestor we're checking against
|
|
*
|
|
* Return:
|
|
*\li boolean - is a at or below b?
|
|
*
|
|
* Notes:
|
|
*\li Trailing dots are first removed from name and domain.
|
|
* Always compare complete subdomains, not only whether the
|
|
* domain name is the trailing string of the given name.
|
|
*
|
|
*\li "host.foobar.top" lies in "foobar.top" and in "top" and in ""
|
|
* but NOT in "bar.top"
|
|
*/
|
|
|
|
int
|
|
ns_samedomain(const char *a, const char *b) {
|
|
size_t la, lb;
|
|
int diff, i, escaped;
|
|
const char *cp;
|
|
|
|
la = strlen(a);
|
|
lb = strlen(b);
|
|
|
|
/* Ignore a trailing label separator (i.e. an unescaped dot) in 'a'. */
|
|
if (la != 0U && a[la - 1] == '.') {
|
|
escaped = 0;
|
|
/* Note this loop doesn't get executed if la==1. */
|
|
for (i = la - 2; i >= 0; i--)
|
|
if (a[i] == '\\') {
|
|
if (escaped)
|
|
escaped = 0;
|
|
else
|
|
escaped = 1;
|
|
} else
|
|
break;
|
|
if (!escaped)
|
|
la--;
|
|
}
|
|
|
|
/* Ignore a trailing label separator (i.e. an unescaped dot) in 'b'. */
|
|
if (lb != 0U && b[lb - 1] == '.') {
|
|
escaped = 0;
|
|
/* note this loop doesn't get executed if lb==1 */
|
|
for (i = lb - 2; i >= 0; i--)
|
|
if (b[i] == '\\') {
|
|
if (escaped)
|
|
escaped = 0;
|
|
else
|
|
escaped = 1;
|
|
} else
|
|
break;
|
|
if (!escaped)
|
|
lb--;
|
|
}
|
|
|
|
/* lb == 0 means 'b' is the root domain, so 'a' must be in 'b'. */
|
|
if (lb == 0U)
|
|
return (1);
|
|
|
|
/* 'b' longer than 'a' means 'a' can't be in 'b'. */
|
|
if (lb > la)
|
|
return (0);
|
|
|
|
/* 'a' and 'b' being equal at this point indicates sameness. */
|
|
if (lb == la)
|
|
return (strncasecmp(a, b, lb) == 0);
|
|
|
|
/* Ok, we know la > lb. */
|
|
|
|
diff = la - lb;
|
|
|
|
/*
|
|
* If 'a' is only 1 character longer than 'b', then it can't be
|
|
* a subdomain of 'b' (because of the need for the '.' label
|
|
* separator).
|
|
*/
|
|
if (diff < 2)
|
|
return (0);
|
|
|
|
/*
|
|
* If the character before the last 'lb' characters of 'b'
|
|
* isn't '.', then it can't be a match (this lets us avoid
|
|
* having "foobar.com" match "bar.com").
|
|
*/
|
|
if (a[diff - 1] != '.')
|
|
return (0);
|
|
|
|
/*
|
|
* We're not sure about that '.', however. It could be escaped
|
|
* and thus not a really a label separator.
|
|
*/
|
|
escaped = 0;
|
|
for (i = diff - 2; i >= 0; i--)
|
|
if (a[i] == '\\') {
|
|
if (escaped)
|
|
escaped = 0;
|
|
else
|
|
escaped = 1;
|
|
} else
|
|
break;
|
|
if (escaped)
|
|
return (0);
|
|
|
|
/* Now compare aligned trailing substring. */
|
|
cp = a + diff;
|
|
return (strncasecmp(cp, b, lb) == 0);
|
|
}
|
|
libresolv_hidden_def (ns_samedomain)
|
|
|
|
/*%
|
|
* is "a" a subdomain of "b"?
|
|
*/
|
|
int
|
|
ns_subdomain (const char *a, const char *b)
|
|
{
|
|
return __libc_ns_samename (a, b) != 1 && ns_samedomain (a, b);
|
|
}
|
|
|
|
/*! \file */
|