gecko/other-licenses/android/ns_samedomain.c

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/* $NetBSD: ns_samedomain.c,v 1.2 2004/05/20 20:35:05 christos Exp $ */
/*
* 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 ISC DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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.
*/
/*
* This version of this file is derived from Android 2.3 "Gingerbread",
* which contains uncredited changes by Android/Google developers. It has
* been modified in 2011 for use in the Android build of Mozilla Firefox by
* Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,
* and Steve Workman <sjhworkman@gmail.com>).
* These changes are offered under the same license as the original NetBSD
* file, whose copyright and license are unchanged above.
*/
#define ANDROID_CHANGES 1
#define MOZILLA_NECKO_EXCLUDE_CODE 1
#include <sys/cdefs.h>
#ifndef lint
#ifdef notdef
static const char rcsid[] = "Id: ns_samedomain.c,v 1.1.2.2.4.2 2004/03/16 12:34:17 marka Exp";
#else
__RCSID("$NetBSD: ns_samedomain.c,v 1.2 2004/05/20 20:35:05 christos Exp $");
#endif
#endif
#include <sys/types.h>
#include "arpa_nameser.h"
#include <errno.h>
#include <string.h>
#ifndef MOZILLA_NECKO_EXCLUDE_CODE
#ifndef _LIBC
/*
* int
* ns_samedomain(a, b)
* Check whether a name belongs to a domain.
* Inputs:
* a - the domain whose ancestory is being verified
* b - the potential ancestor we're checking against
* Return:
* boolean - is a at or below b?
* Notes:
* 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.
*
* "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);
}
/*
* int
* ns_subdomain(a, b)
* is "a" a subdomain of "b"?
*/
int
ns_subdomain(const char *a, const char *b) {
return (ns_samename(a, b) != 1 && ns_samedomain(a, b));
}
#endif
#endif
/*
* int
* ns_makecanon(src, dst, dstsize)
* make a canonical copy of domain name "src"
* notes:
* foo -> foo.
* foo. -> foo.
* foo.. -> foo.
* foo\. -> foo\..
* foo\\. -> foo\\.
*/
int
ns_makecanon(const char *src, char *dst, size_t dstsize) {
size_t n = strlen(src);
if (n + sizeof "." > dstsize) { /* Note: sizeof == 2 */
errno = EMSGSIZE;
return (-1);
}
strcpy(dst, src);
while (n >= 1U && dst[n - 1] == '.') /* Ends in "." */
if (n >= 2U && dst[n - 2] == '\\' && /* Ends in "\." */
(n < 3U || dst[n - 3] != '\\')) /* But not "\\." */
break;
else
dst[--n] = '\0';
dst[n++] = '.';
dst[n] = '\0';
return (0);
}
/*
* int
* ns_samename(a, b)
* determine whether domain name "a" is the same as domain name "b"
* return:
* -1 on error
* 0 if names differ
* 1 if names are the same
*/
int
ns_samename(const char *a, const char *b) {
char ta[NS_MAXDNAME], tb[NS_MAXDNAME];
if (ns_makecanon(a, ta, sizeof ta) < 0 ||
ns_makecanon(b, tb, sizeof tb) < 0)
return (-1);
if (strcasecmp(ta, tb) == 0)
return (1);
else
return (0);
}