The Tor Browser: other-licenses/android/ns_samedomain.c@7e26c7da4463 (annotated)

other-licenses/android/ns_samedomain.c@7e26c7da4463 (annotated)

other-licenses/android/ns_samedomain.c

Wed, 31 Dec 2014 06:55:50 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:55:50 +0100
changeset 2: 7e26c7da4463
permissions: -rw-r--r--

Added tag UPSTREAM_283F7C6 for changeset ca08bd8f51b2

 /*	$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);
 }

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other-licenses/android/ns_samedomain.c