libc/dns/nameser/ns_parse.c - platform/bionic - Git at Google

 /*	$NetBSD: ns_parse.c,v 1.9 2012/03/13 21:13:39 christos Exp $	*/

 /*
  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
  * Copyright (c) 1996,1999 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.
  */

 #include <sys/cdefs.h>
 #ifndef lint
 #ifdef notdef
 static const char rcsid[] = "Id: ns_parse.c,v 1.10 2009/01/23 19:59:16 each Exp";
 #else
 __RCSID("$NetBSD: ns_parse.c,v 1.9 2012/03/13 21:13:39 christos Exp $");
 #endif
 #endif

 /* Import. */

 #include <sys/types.h>

 #include <netinet/in.h>
 #include <arpa/nameser.h>

 #include <assert.h>
 #include <errno.h>
 #ifdef ANDROID_CHANGES
 #include "resolv_private.h"
 #else
 #include <resolv.h>
 #endif
 #include <string.h>

 /* Forward. */

 static void	setsection(ns_msg *msg, ns_sect sect);

 /* Macros. */

 #define RETERR(err) do { errno = (err); return (-1); } while (/*NOTREACHED*//*CONSTCOND*/0)

 /* Public. */

 struct _ns_flagdata {  int mask, shift;  };

 /* These need to be in the same order as the nres.h:ns_flag enum. */
 const struct _ns_flagdata _ns_flagdata[16] = {
 	{ 0x8000, 15 },		/* qr. */
 	{ 0x7800, 11 },		/* opcode. */
 	{ 0x0400, 10 },		/* aa. */
 	{ 0x0200, 9 },		/* tc. */
 	{ 0x0100, 8 },		/* rd. */
 	{ 0x0080, 7 },		/* ra. */
 	{ 0x0040, 6 },		/* z. */
 	{ 0x0020, 5 },		/* ad. */
 	{ 0x0010, 4 },		/* cd. */
 	{ 0x000f, 0 },		/* rcode. */
 	{ 0x0000, 0 },		/* expansion (1/6). */
 	{ 0x0000, 0 },		/* expansion (2/6). */
 	{ 0x0000, 0 },		/* expansion (3/6). */
 	{ 0x0000, 0 },		/* expansion (4/6). */
 	{ 0x0000, 0 },		/* expansion (5/6). */
 	{ 0x0000, 0 },		/* expansion (6/6). */
 };

 int ns_msg_getflag(ns_msg handle, int flag) {
 	return((u_int32_t)((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift);
 }

 int
 ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
 	const u_char *optr = ptr;

 	for (; count > 0; count--) {
 		int b, rdlength;

 		b = dn_skipname(ptr, eom);
 		if (b < 0)
 			RETERR(EMSGSIZE);
 		ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
 		if (section != ns_s_qd) {
 			if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
 				RETERR(EMSGSIZE);
 			ptr += NS_INT32SZ/*TTL*/;
 			NS_GET16(rdlength, ptr);
 			ptr += rdlength/*RData*/;
 		}
 	}
 	if (ptr > eom)
 		RETERR(EMSGSIZE);
 	_DIAGASSERT(__type_fit(int, ptr - optr));
 	return (int)(ptr - optr);
 }

 int
 ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
 	const u_char *eom = msg + msglen;
 	int i;

 	handle->_msg = msg;
 	handle->_eom = eom;
 	if (msg + NS_INT16SZ > eom)
 		RETERR(EMSGSIZE);
 	NS_GET16(handle->_id, msg);
 	if (msg + NS_INT16SZ > eom)
 		RETERR(EMSGSIZE);
 	NS_GET16(handle->_flags, msg);
 	for (i = 0; i < ns_s_max; i++) {
 		if (msg + NS_INT16SZ > eom)
 			RETERR(EMSGSIZE);
 		NS_GET16(handle->_counts[i], msg);
 	}
 	for (i = 0; i < ns_s_max; i++)
 		if (handle->_counts[i] == 0)
 			handle->_sections[i] = NULL;
 		else {
 			int b = ns_skiprr(msg, eom, (ns_sect)i,
 					  handle->_counts[i]);

 			if (b < 0)
 				return (-1);
 			handle->_sections[i] = msg;
 			msg += b;
 		}
 	if (msg != eom)
 		RETERR(EMSGSIZE);
 	setsection(handle, ns_s_max);
 	return (0);
 }

 int
 ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
 	int b;
 	int tmp;

 	/* Make section right. */
 	tmp = section;
 	if (tmp < 0 || section >= ns_s_max)
 		RETERR(ENODEV);
 	if (section != handle->_sect)
 		setsection(handle, section);

 	/* Make rrnum right. */
 	if (rrnum == -1)
 		rrnum = handle->_rrnum;
 	if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
 		RETERR(ENODEV);
 	if (rrnum < handle->_rrnum)
 		setsection(handle, section);
 	if (rrnum > handle->_rrnum) {
 		b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
 			      rrnum - handle->_rrnum);

 		if (b < 0)
 			return (-1);
 		handle->_msg_ptr += b;
 		handle->_rrnum = rrnum;
 	}

 	/* Do the parse. */
 	b = dn_expand(handle->_msg, handle->_eom,
 		      handle->_msg_ptr, rr->name, NS_MAXDNAME);
 	if (b < 0)
 		return (-1);
 	handle->_msg_ptr += b;
 	if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
 		RETERR(EMSGSIZE);
 	NS_GET16(rr->type, handle->_msg_ptr);
 	NS_GET16(rr->rr_class, handle->_msg_ptr);
 	if (section == ns_s_qd) {
 		rr->ttl = 0;
 		rr->rdlength = 0;
 		rr->rdata = NULL;
 	} else {
 		if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
 			RETERR(EMSGSIZE);
 		NS_GET32(rr->ttl, handle->_msg_ptr);
 		NS_GET16(rr->rdlength, handle->_msg_ptr);
 		if (handle->_msg_ptr + rr->rdlength > handle->_eom)
 			RETERR(EMSGSIZE);
 		rr->rdata = handle->_msg_ptr;
 		handle->_msg_ptr += rr->rdlength;
 	}
 	if (++handle->_rrnum > handle->_counts[(int)section])
 		setsection(handle, (ns_sect)((int)section + 1));

 	/* All done. */
 	return (0);
 }

 /*
  * This is identical to the above but uses network-format (uncompressed) names.
  */
 int
 ns_parserr2(ns_msg *handle, ns_sect section, int rrnum, ns_rr2 *rr) {
 	int b;
 	int tmp;

 	/* Make section right. */
 	tmp = section;
 	if (tmp < 0 || section >= ns_s_max)
 		RETERR(ENODEV);
 	if (section != handle->_sect)
 		setsection(handle, section);

 	/* Make rrnum right. */
 	if (rrnum == -1)
 		rrnum = handle->_rrnum;
 	if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
 		RETERR(ENODEV);
 	if (rrnum < handle->_rrnum)
 		setsection(handle, section);
 	if (rrnum > handle->_rrnum) {
 		b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
 			      rrnum - handle->_rrnum);

 		if (b < 0)
 			return (-1);
 		handle->_msg_ptr += b;
 		handle->_rrnum = rrnum;
 	}

 	/* Do the parse. */
 	b = ns_name_unpack2(handle->_msg, handle->_eom, handle->_msg_ptr,
 			    rr->nname, NS_MAXNNAME, &rr->nnamel);
 	if (b < 0)
 		return (-1);
 	handle->_msg_ptr += b;
 	if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
 		RETERR(EMSGSIZE);
 	NS_GET16(rr->type, handle->_msg_ptr);
 	NS_GET16(rr->rr_class, handle->_msg_ptr);
 	if (section == ns_s_qd) {
 		rr->ttl = 0;
 		rr->rdlength = 0;
 		rr->rdata = NULL;
 	} else {
 		if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
 			RETERR(EMSGSIZE);
 		NS_GET32(rr->ttl, handle->_msg_ptr);
 		NS_GET16(rr->rdlength, handle->_msg_ptr);
 		if (handle->_msg_ptr + rr->rdlength > handle->_eom)
 			RETERR(EMSGSIZE);
 		rr->rdata = handle->_msg_ptr;
 		handle->_msg_ptr += rr->rdlength;
 	}
 	if (++handle->_rrnum > handle->_counts[(int)section])
 		setsection(handle, (ns_sect)((int)section + 1));

 	/* All done. */
 	return (0);
 }

 /* Private. */

 static void
 setsection(ns_msg *msg, ns_sect sect) {
 	msg->_sect = sect;
 	if (sect == ns_s_max) {
 		msg->_rrnum = -1;
 		msg->_msg_ptr = NULL;
 	} else {
 		msg->_rrnum = 0;
 		msg->_msg_ptr = msg->_sections[(int)sect];
 	}
 }
	/* $NetBSD: ns_parse.c,v 1.9 2012/03/13 21:13:39 christos Exp $ */

	/*
	* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
	* Copyright (c) 1996,1999 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.
	*/

	#include <sys/cdefs.h>
	#ifndef lint
	#ifdef notdef
	static const char rcsid[] = "Id: ns_parse.c,v 1.10 2009/01/23 19:59:16 each Exp";
	#else
	__RCSID("$NetBSD: ns_parse.c,v 1.9 2012/03/13 21:13:39 christos Exp $");
	#endif
	#endif

	/* Import. */

	#include <sys/types.h>

	#include <netinet/in.h>
	#include <arpa/nameser.h>

	#include <assert.h>
	#include <errno.h>
	#ifdef ANDROID_CHANGES
	#include "resolv_private.h"
	#else
	#include <resolv.h>
	#endif
	#include <string.h>

	/* Forward. */

	static void setsection(ns_msg *msg, ns_sect sect);

	/* Macros. */

	#define RETERR(err) do { errno = (err); return (-1); } while (/NOTREACHED//CONSTCOND/0)

	/* Public. */

	struct _ns_flagdata { int mask, shift; };

	/* These need to be in the same order as the nres.h:ns_flag enum. */
	const struct _ns_flagdata _ns_flagdata[16] = {
	{ 0x8000, 15 }, /* qr. */
	{ 0x7800, 11 }, /* opcode. */
	{ 0x0400, 10 }, /* aa. */
	{ 0x0200, 9 }, /* tc. */
	{ 0x0100, 8 }, /* rd. */
	{ 0x0080, 7 }, /* ra. */
	{ 0x0040, 6 }, /* z. */
	{ 0x0020, 5 }, /* ad. */
	{ 0x0010, 4 }, /* cd. */
	{ 0x000f, 0 }, /* rcode. */
	{ 0x0000, 0 }, /* expansion (1/6). */
	{ 0x0000, 0 }, /* expansion (2/6). */
	{ 0x0000, 0 }, /* expansion (3/6). */
	{ 0x0000, 0 }, /* expansion (4/6). */
	{ 0x0000, 0 }, /* expansion (5/6). */
	{ 0x0000, 0 }, /* expansion (6/6). */
	};

	int ns_msg_getflag(ns_msg handle, int flag) {
	return((u_int32_t)((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift);
	}

	int
	ns_skiprr(const u_char ptr, const u_char eom, ns_sect section, int count) {
	const u_char *optr = ptr;

	for (; count > 0; count--) {
	int b, rdlength;

	b = dn_skipname(ptr, eom);
	if (b < 0)
	RETERR(EMSGSIZE);
	ptr += b/Name/ + NS_INT16SZ/Type/ + NS_INT16SZ/Class/;
	if (section != ns_s_qd) {
	if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
	RETERR(EMSGSIZE);
	ptr += NS_INT32SZ/TTL/;
	NS_GET16(rdlength, ptr);
	ptr += rdlength/RData/;
	}
	}
	if (ptr > eom)
	RETERR(EMSGSIZE);
	_DIAGASSERT(__type_fit(int, ptr - optr));
	return (int)(ptr - optr);
	}

	int
	ns_initparse(const u_char msg, int msglen, ns_msg handle) {
	const u_char *eom = msg + msglen;
	int i;

	handle->_msg = msg;
	handle->_eom = eom;
	if (msg + NS_INT16SZ > eom)
	RETERR(EMSGSIZE);
	NS_GET16(handle->_id, msg);
	if (msg + NS_INT16SZ > eom)
	RETERR(EMSGSIZE);
	NS_GET16(handle->_flags, msg);
	for (i = 0; i < ns_s_max; i++) {
	if (msg + NS_INT16SZ > eom)
	RETERR(EMSGSIZE);
	NS_GET16(handle->_counts[i], msg);
	}
	for (i = 0; i < ns_s_max; i++)
	if (handle->_counts[i] == 0)
	handle->_sections[i] = NULL;
	else {
	int b = ns_skiprr(msg, eom, (ns_sect)i,
	handle->_counts[i]);

	if (b < 0)
	return (-1);
	handle->_sections[i] = msg;
	msg += b;
	}
	if (msg != eom)
	RETERR(EMSGSIZE);
	setsection(handle, ns_s_max);
	return (0);
	}

	int
	ns_parserr(ns_msg handle, ns_sect section, int rrnum, ns_rr rr) {
	int b;
	int tmp;

	/* Make section right. */
	tmp = section;
	if (tmp < 0 \|\| section >= ns_s_max)
	RETERR(ENODEV);
	if (section != handle->_sect)
	setsection(handle, section);

	/* Make rrnum right. */
	if (rrnum == -1)
	rrnum = handle->_rrnum;
	if (rrnum < 0 \|\| rrnum >= handle->_counts[(int)section])
	RETERR(ENODEV);
	if (rrnum < handle->_rrnum)
	setsection(handle, section);
	if (rrnum > handle->_rrnum) {
	b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
	rrnum - handle->_rrnum);

	if (b < 0)
	return (-1);
	handle->_msg_ptr += b;
	handle->_rrnum = rrnum;
	}

	/* Do the parse. */
	b = dn_expand(handle->_msg, handle->_eom,
	handle->_msg_ptr, rr->name, NS_MAXDNAME);
	if (b < 0)
	return (-1);
	handle->_msg_ptr += b;
	if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
	RETERR(EMSGSIZE);
	NS_GET16(rr->type, handle->_msg_ptr);
	NS_GET16(rr->rr_class, handle->_msg_ptr);
	if (section == ns_s_qd) {
	rr->ttl = 0;
	rr->rdlength = 0;
	rr->rdata = NULL;
	} else {
	if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
	RETERR(EMSGSIZE);
	NS_GET32(rr->ttl, handle->_msg_ptr);
	NS_GET16(rr->rdlength, handle->_msg_ptr);
	if (handle->_msg_ptr + rr->rdlength > handle->_eom)
	RETERR(EMSGSIZE);
	rr->rdata = handle->_msg_ptr;
	handle->_msg_ptr += rr->rdlength;
	}
	if (++handle->_rrnum > handle->_counts[(int)section])
	setsection(handle, (ns_sect)((int)section + 1));

	/* All done. */
	return (0);
	}

	/*
	* This is identical to the above but uses network-format (uncompressed) names.
	*/
	int
	ns_parserr2(ns_msg handle, ns_sect section, int rrnum, ns_rr2 rr) {
	int b;
	int tmp;

	/* Make section right. */
	tmp = section;
	if (tmp < 0 \|\| section >= ns_s_max)
	RETERR(ENODEV);
	if (section != handle->_sect)
	setsection(handle, section);

	/* Make rrnum right. */
	if (rrnum == -1)
	rrnum = handle->_rrnum;
	if (rrnum < 0 \|\| rrnum >= handle->_counts[(int)section])
	RETERR(ENODEV);
	if (rrnum < handle->_rrnum)
	setsection(handle, section);
	if (rrnum > handle->_rrnum) {
	b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
	rrnum - handle->_rrnum);

	if (b < 0)
	return (-1);
	handle->_msg_ptr += b;
	handle->_rrnum = rrnum;
	}

	/* Do the parse. */
	b = ns_name_unpack2(handle->_msg, handle->_eom, handle->_msg_ptr,
	rr->nname, NS_MAXNNAME, &rr->nnamel);
	if (b < 0)
	return (-1);
	handle->_msg_ptr += b;
	if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
	RETERR(EMSGSIZE);
	NS_GET16(rr->type, handle->_msg_ptr);
	NS_GET16(rr->rr_class, handle->_msg_ptr);
	if (section == ns_s_qd) {
	rr->ttl = 0;
	rr->rdlength = 0;
	rr->rdata = NULL;
	} else {
	if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
	RETERR(EMSGSIZE);
	NS_GET32(rr->ttl, handle->_msg_ptr);
	NS_GET16(rr->rdlength, handle->_msg_ptr);
	if (handle->_msg_ptr + rr->rdlength > handle->_eom)
	RETERR(EMSGSIZE);
	rr->rdata = handle->_msg_ptr;
	handle->_msg_ptr += rr->rdlength;
	}
	if (++handle->_rrnum > handle->_counts[(int)section])
	setsection(handle, (ns_sect)((int)section + 1));

	/* All done. */
	return (0);
	}

	/* Private. */

	static void
	setsection(ns_msg *msg, ns_sect sect) {
	msg->_sect = sect;
	if (sect == ns_s_max) {
	msg->_rrnum = -1;
	msg->_msg_ptr = NULL;
	} else {
	msg->_rrnum = 0;
	msg->_msg_ptr = msg->_sections[(int)sect];
	}
	}