[thirdparty/glibc.git] / resolv / res_mkquery.c

/* Creation of DNS query packets.
   Copyright (C) 1995-2017 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

/*
 * Copyright (c) 1985, 1993
 *    The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
 *
 * 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, and that
 * the name of Digital Equipment Corporation not be used in advertising or
 * publicity pertaining to distribution of the document or software without
 * specific, written prior permission.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
 * CORPORATION 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.
 */

/*
 * Portions 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 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 <sys/param.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <resolv/resolv-internal.h>
#include <string.h>
#include <sys/time.h>

#include <hp-timing.h>
#include <stdint.h>
#if HP_TIMING_AVAIL
# define RANDOM_BITS(Var) { uint64_t v64; HP_TIMING_NOW (v64); Var = v64; }
#endif

/*
 * Form all types of queries.
 * Returns the size of the result or -1.
 */
int
res_nmkquery(res_state statp,
	     int op,			/* opcode of query */
	     const char *dname,		/* domain name */
	     int class, int type,	/* class and type of query */
	     const u_char *data,	/* resource record data */
	     int datalen,		/* length of data */
	     const u_char *newrr_in,	/* new rr for modify or append */
	     u_char *buf,		/* buffer to put query */
	     int buflen)		/* size of buffer */
{
	HEADER *hp;
	u_char *cp;
	int n;
	u_char *dnptrs[20], **dpp, **lastdnptr;

	if (class < 0 || class > 65535
	    || type < 0 || type > 65535)
	  return -1;

	/*
	 * Initialize header fields.
	 */
	if ((buf == NULL) || (buflen < HFIXEDSZ))
		return (-1);
	memset(buf, 0, HFIXEDSZ);
	hp = (HEADER *) buf;
	/* We randomize the IDs every time.  The old code just
	   incremented by one after the initial randomization which
	   still predictable if the application does multiple
	   requests.  */
	int randombits;
	do
	  {
#ifdef RANDOM_BITS
	    RANDOM_BITS (randombits);
#else
	    struct timeval tv;
	    __gettimeofday (&tv, NULL);
	    randombits = (tv.tv_sec << 8) ^ tv.tv_usec;
#endif
	  }
	while ((randombits & 0xffff) == 0);
	statp->id = (statp->id + randombits) & 0xffff;
	hp->id = statp->id;
	hp->opcode = op;
	hp->rd = (statp->options & RES_RECURSE) != 0;
	hp->rcode = NOERROR;
	cp = buf + HFIXEDSZ;
	buflen -= HFIXEDSZ;
	dpp = dnptrs;
	*dpp++ = buf;
	*dpp++ = NULL;
	lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
	/*
	 * perform opcode specific processing
	 */
	switch (op) {
	case NS_NOTIFY_OP:
		if ((buflen -= QFIXEDSZ + (data == NULL ? 0 : RRFIXEDSZ)) < 0)
			return (-1);
		goto compose;

	case QUERY:
		if ((buflen -= QFIXEDSZ) < 0)
			return (-1);
	compose:
		n = ns_name_compress(dname, cp, buflen,
				     (const u_char **) dnptrs,
				     (const u_char **) lastdnptr);
		if (n < 0)
			return (-1);
		cp += n;
		buflen -= n;
		NS_PUT16 (type, cp);
		NS_PUT16 (class, cp);
		hp->qdcount = htons(1);
		if (op == QUERY || data == NULL)
			break;
		/*
		 * Make an additional record for completion domain.
		 */
		n = ns_name_compress((char *)data, cp, buflen,
				     (const u_char **) dnptrs,
				     (const u_char **) lastdnptr);
		if (__glibc_unlikely (n < 0))
			return (-1);
		cp += n;
		buflen -= n;
		NS_PUT16 (T_NULL, cp);
		NS_PUT16 (class, cp);
		NS_PUT32 (0, cp);
		NS_PUT16 (0, cp);
		hp->arcount = htons(1);
		break;

	default:
		return (-1);
	}
	return (cp - buf);
}
libresolv_hidden_def (res_nmkquery)


/* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
#ifndef T_OPT
#define T_OPT   41
#endif

int
__res_nopt(res_state statp,
	   int n0,                /* current offset in buffer */
	   u_char *buf,           /* buffer to put query */
	   int buflen,            /* size of buffer */
	   int anslen)            /* UDP answer buffer size */
{
	u_int16_t flags = 0;

	HEADER *hp = (HEADER *) buf;
	u_char *cp = buf + n0;
	u_char *ep = buf + buflen;

	if ((ep - cp) < 1 + RRFIXEDSZ)
		return -1;

	*cp++ = 0;	/* "." */

	NS_PUT16(T_OPT, cp);	/* TYPE */

	/* Lowering the advertised buffer size based on the actual
	   answer buffer size is desirable because the server will
	   minimize the reply to fit into the UDP packet (and A
	   non-minimal response might not fit the buffer).

	   The RESOLV_EDNS_BUFFER_SIZE limit could still result in TCP
	   fallback and a non-minimal response which has to be
	   hard-truncated in the stub resolver, but this is price to
	   pay for avoiding fragmentation.  (This issue does not
	   affect the nss_dns functions because they use the stub
	   resolver in such a way that it allocates a properly sized
	   response buffer.)  */
	{
	  uint16_t buffer_size;
	  if (anslen < 512)
	    buffer_size = 512;
	  else if (anslen > RESOLV_EDNS_BUFFER_SIZE)
	    buffer_size = RESOLV_EDNS_BUFFER_SIZE;
	  else
	    buffer_size = anslen;
	  NS_PUT16 (buffer_size, cp);
	}

	*cp++ = NOERROR;	/* extended RCODE */
	*cp++ = 0;		/* EDNS version */

	if (statp->options & RES_USE_DNSSEC) {
		flags |= NS_OPT_DNSSEC_OK;
	}

	NS_PUT16(flags, cp);
	NS_PUT16(0, cp);	/* RDLEN */
	hp->arcount = htons(ntohs(hp->arcount) + 1);

	return cp - buf;
}
Commit	Line	Data
7ab27b76 FW	1	/* Creation of DNS query packets.
	2	Copyright (C) 1995-2017 Free Software Foundation, Inc.
	3	This file is part of the GNU C Library.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
	16	License along with the GNU C Library; if not, see
	17	<http://www.gnu.org/licenses/>. */
	18
28f540f4	19	/*
28f540f4 RM	20	* Copyright (c) 1985, 1993
28f540f4 RM	21	* The Regents of the University of California. All rights reserved.
e33b89df	22	*
28f540f4 RM	23	* Redistribution and use in source and binary forms, with or without
	24	* modification, are permitted provided that the following conditions
	25	* are met:
	26	* 1. Redistributions of source code must retain the above copyright
	27	* notice, this list of conditions and the following disclaimer.
	28	* 2. Redistributions in binary form must reproduce the above copyright
	29	* notice, this list of conditions and the following disclaimer in the
	30	* documentation and/or other materials provided with the distribution.
28f540f4 RM	31	* 4. Neither the name of the University nor the names of its contributors
	32	* may be used to endorse or promote products derived from this software
	33	* without specific prior written permission.
e33b89df	34	*
28f540f4 RM	35	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	36	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	37	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	38	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	39	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	40	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	41	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	42	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	43	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	44	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	45	* SUCH DAMAGE.
b43b13ac UD	46	*/
	47
	48	/*
28f540f4	49	* Portions Copyright (c) 1993 by Digital Equipment Corporation.
e33b89df	50	*
28f540f4 RM	51	* Permission to use, copy, modify, and distribute this software for any
	52	* purpose with or without fee is hereby granted, provided that the above
	53	* copyright notice and this permission notice appear in all copies, and that
	54	* the name of Digital Equipment Corporation not be used in advertising or
	55	* publicity pertaining to distribution of the document or software without
	56	* specific, written prior permission.
e33b89df	57	*
28f540f4 RM	58	* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
	59	* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
	60	* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
	61	* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
	62	* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
	63	* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
	64	* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
	65	* SOFTWARE.
b43b13ac UD	66	*/
	67
	68	/*
	69	* Portions Copyright (c) 1996-1999 by Internet Software Consortium.
	70	*
	71	* Permission to use, copy, modify, and distribute this software for any
	72	* purpose with or without fee is hereby granted, provided that the above
	73	* copyright notice and this permission notice appear in all copies.
	74	*
	75	* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
	76	* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
	77	* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
	78	* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
	79	* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
	80	* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
	81	* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
	82	* SOFTWARE.
28f540f4 RM	83	*/
28f540f4 RM	84
df21c858	85	#include <sys/types.h>
28f540f4 RM	86	#include <sys/param.h>
	87	#include <netinet/in.h>
	88	#include <arpa/nameser.h>
3d61b63c	89	#include <netdb.h>
e14a2772	90	#include <resolv/resolv-internal.h>
b43b13ac	91	#include <string.h>
f890a59b	92	#include <sys/time.h>
28f540f4	93
ed3c7876 FW	94	#include <hp-timing.h>
	95	#include <stdint.h>
	96	#if HP_TIMING_AVAIL
	97	# define RANDOM_BITS(Var) { uint64_t v64; HP_TIMING_NOW (v64); Var = v64; }
	98	#endif
e33b89df	99
28f540f4 RM	100	/*
	101	* Form all types of queries.
	102	* Returns the size of the result or -1.
	103	*/
	104	int
b43b13ac UD	105	res_nmkquery(res_state statp,
	106	int op, /* opcode of query */
	107	const char dname, / domain name */
	108	int class, int type, /* class and type of query */
	109	const u_char data, / resource record data */
	110	int datalen, /* length of data */
	111	const u_char newrr_in, / new rr for modify or append */
	112	u_char buf, / buffer to put query */
	113	int buflen) /* size of buffer */
28f540f4	114	{
2e09a79a JM	115	HEADER *hp;
	116	u_char *cp;
	117	int n;
28f540f4 RM	118	u_char dnptrs[20], dpp, *lastdnptr;
28f540f4 RM	119
fc82b0a2 FW	120	if (class < 0 \|\| class > 65535
	121	\|\| type < 0 \|\| type > 65535)
	122	return -1;
	123
28f540f4 RM	124	/*
	125	* Initialize header fields.
	126	*/
	127	if ((buf == NULL) \|\| (buflen < HFIXEDSZ))
	128	return (-1);
b43b13ac	129	memset(buf, 0, HFIXEDSZ);
28f540f4	130	hp = (HEADER *) buf;
e33b89df UD	131	/* We randomize the IDs every time. The old code just
	132	incremented by one after the initial randomization which
	133	still predictable if the application does multiple
	134	requests. */
e33b89df UD	135	int randombits;
	136	do
	137	{
03eeff83	138	#ifdef RANDOM_BITS
e33b89df	139	RANDOM_BITS (randombits);
03eeff83	140	#else
e33b89df UD	141	struct timeval tv;
e33b89df UD	142	__gettimeofday (&tv, NULL);
29e11320	143	randombits = (tv.tv_sec << 8) ^ tv.tv_usec;
03eeff83	144	#endif
e33b89df	145	}
3feb8efa	146	while ((randombits & 0xffff) == 0);
e33b89df	147	statp->id = (statp->id + randombits) & 0xffff;
03eeff83	148	hp->id = statp->id;
28f540f4	149	hp->opcode = op;
b43b13ac	150	hp->rd = (statp->options & RES_RECURSE) != 0;
28f540f4 RM	151	hp->rcode = NOERROR;
	152	cp = buf + HFIXEDSZ;
	153	buflen -= HFIXEDSZ;
	154	dpp = dnptrs;
	155	*dpp++ = buf;
	156	*dpp++ = NULL;
	157	lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
	158	/*
	159	* perform opcode specific processing
	160	*/
	161	switch (op) {
28f540f4	162	case NS_NOTIFY_OP:
bce16467 UD	163	if ((buflen -= QFIXEDSZ + (data == NULL ? 0 : RRFIXEDSZ)) < 0)
	164	return (-1);
	165	goto compose;
	166
	167	case QUERY:
28f540f4 RM	168	if ((buflen -= QFIXEDSZ) < 0)
28f540f4 RM	169	return (-1);
bce16467	170	compose:
be1c55f2 UD	171	n = ns_name_compress(dname, cp, buflen,
	172	(const u_char **) dnptrs,
	173	(const u_char **) lastdnptr);
	174	if (n < 0)
28f540f4 RM	175	return (-1);
	176	cp += n;
	177	buflen -= n;
bce16467 UD	178	NS_PUT16 (type, cp);
bce16467 UD	179	NS_PUT16 (class, cp);
28f540f4 RM	180	hp->qdcount = htons(1);
	181	if (op == QUERY \|\| data == NULL)
	182	break;
	183	/*
	184	* Make an additional record for completion domain.
	185	*/
be1c55f2 UD	186	n = ns_name_compress((char *)data, cp, buflen,
	187	(const u_char **) dnptrs,
	188	(const u_char **) lastdnptr);
a1ffb40e	189	if (__glibc_unlikely (n < 0))
28f540f4 RM	190	return (-1);
	191	cp += n;
	192	buflen -= n;
bce16467 UD	193	NS_PUT16 (T_NULL, cp);
	194	NS_PUT16 (class, cp);
	195	NS_PUT32 (0, cp);
	196	NS_PUT16 (0, cp);
28f540f4 RM	197	hp->arcount = htons(1);
	198	break;
	199
28f540f4 RM	200	default:
	201	return (-1);
	202	}
	203	return (cp - buf);
	204	}
6f9d8e68	205	libresolv_hidden_def (res_nmkquery)
2bbb7d5b UD	206
	207
	208	/* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */
	209	#ifndef T_OPT
	210	#define T_OPT 41
	211	#endif
	212
	213	int
	214	__res_nopt(res_state statp,
	215	int n0, /* current offset in buffer */
	216	u_char buf, / buffer to put query */
	217	int buflen, /* size of buffer */
	218	int anslen) /* UDP answer buffer size */
	219	{
	220	u_int16_t flags = 0;
	221
2bbb7d5b UD	222	HEADER hp = (HEADER ) buf;
	223	u_char *cp = buf + n0;
	224	u_char *ep = buf + buflen;
	225
	226	if ((ep - cp) < 1 + RRFIXEDSZ)
	227	return -1;
	228
	229	cp++ = 0; / "." */
	230
0073dd2d	231	NS_PUT16(T_OPT, cp); /* TYPE */
e14a2772 FW	232
	233	/* Lowering the advertised buffer size based on the actual
	234	answer buffer size is desirable because the server will
	235	minimize the reply to fit into the UDP packet (and A
	236	non-minimal response might not fit the buffer).
	237
	238	The RESOLV_EDNS_BUFFER_SIZE limit could still result in TCP
	239	fallback and a non-minimal response which has to be
	240	hard-truncated in the stub resolver, but this is price to
	241	pay for avoiding fragmentation. (This issue does not
	242	affect the nss_dns functions because they use the stub
	243	resolver in such a way that it allocates a properly sized
	244	response buffer.) */
	245	{
	246	uint16_t buffer_size;
	247	if (anslen < 512)
	248	buffer_size = 512;
	249	else if (anslen > RESOLV_EDNS_BUFFER_SIZE)
	250	buffer_size = RESOLV_EDNS_BUFFER_SIZE;
	251	else
	252	buffer_size = anslen;
	253	NS_PUT16 (buffer_size, cp);
	254	}
	255
2bbb7d5b UD	256	cp++ = NOERROR; / extended RCODE */
2bbb7d5b UD	257	cp++ = 0; / EDNS version */
2d0671cb AT	258
2d0671cb AT	259	if (statp->options & RES_USE_DNSSEC) {
2d0671cb AT	260	flags \|= NS_OPT_DNSSEC_OK;
	261	}
	262
0073dd2d UD	263	NS_PUT16(flags, cp);
0073dd2d UD	264	NS_PUT16(0, cp); /* RDLEN */
2bbb7d5b UD	265	hp->arcount = htons(ntohs(hp->arcount) + 1);
	266
	267	return cp - buf;
	268	}