|
Packit |
6c4009 |
/* Creation of DNS query packets.
|
|
Packit |
6c4009 |
Copyright (C) 1995-2018 Free Software Foundation, Inc.
|
|
Packit |
6c4009 |
This file is part of the GNU C Library.
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
The GNU C Library is free software; you can redistribute it and/or
|
|
Packit |
6c4009 |
modify it under the terms of the GNU Lesser General Public
|
|
Packit |
6c4009 |
License as published by the Free Software Foundation; either
|
|
Packit |
6c4009 |
version 2.1 of the License, or (at your option) any later version.
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
The GNU C Library is distributed in the hope that it will be useful,
|
|
Packit |
6c4009 |
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
Packit |
6c4009 |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Packit |
6c4009 |
Lesser General Public License for more details.
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
You should have received a copy of the GNU Lesser General Public
|
|
Packit |
6c4009 |
License along with the GNU C Library; if not, see
|
|
Packit |
6c4009 |
<http://www.gnu.org/licenses/>. */
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/*
|
|
Packit |
6c4009 |
* Copyright (c) 1985, 1993
|
|
Packit |
6c4009 |
* The Regents of the University of California. All rights reserved.
|
|
Packit |
6c4009 |
*
|
|
Packit |
6c4009 |
* Redistribution and use in source and binary forms, with or without
|
|
Packit |
6c4009 |
* modification, are permitted provided that the following conditions
|
|
Packit |
6c4009 |
* are met:
|
|
Packit |
6c4009 |
* 1. Redistributions of source code must retain the above copyright
|
|
Packit |
6c4009 |
* notice, this list of conditions and the following disclaimer.
|
|
Packit |
6c4009 |
* 2. Redistributions in binary form must reproduce the above copyright
|
|
Packit |
6c4009 |
* notice, this list of conditions and the following disclaimer in the
|
|
Packit |
6c4009 |
* documentation and/or other materials provided with the distribution.
|
|
Packit |
6c4009 |
* 4. Neither the name of the University nor the names of its contributors
|
|
Packit |
6c4009 |
* may be used to endorse or promote products derived from this software
|
|
Packit |
6c4009 |
* without specific prior written permission.
|
|
Packit |
6c4009 |
*
|
|
Packit |
6c4009 |
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
Packit |
6c4009 |
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
Packit |
6c4009 |
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
Packit |
6c4009 |
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
Packit |
6c4009 |
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
Packit |
6c4009 |
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
Packit |
6c4009 |
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
Packit |
6c4009 |
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
Packit |
6c4009 |
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
Packit |
6c4009 |
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
Packit |
6c4009 |
* SUCH DAMAGE.
|
|
Packit |
6c4009 |
*/
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/*
|
|
Packit |
6c4009 |
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
|
|
Packit |
6c4009 |
*
|
|
Packit |
6c4009 |
* Permission to use, copy, modify, and distribute this software for any
|
|
Packit |
6c4009 |
* purpose with or without fee is hereby granted, provided that the above
|
|
Packit |
6c4009 |
* copyright notice and this permission notice appear in all copies, and that
|
|
Packit |
6c4009 |
* the name of Digital Equipment Corporation not be used in advertising or
|
|
Packit |
6c4009 |
* publicity pertaining to distribution of the document or software without
|
|
Packit |
6c4009 |
* specific, written prior permission.
|
|
Packit |
6c4009 |
*
|
|
Packit |
6c4009 |
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
|
|
Packit |
6c4009 |
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
|
|
Packit |
6c4009 |
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
|
|
Packit |
6c4009 |
* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
|
|
Packit |
6c4009 |
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
|
Packit |
6c4009 |
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
|
|
Packit |
6c4009 |
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
|
|
Packit |
6c4009 |
* SOFTWARE.
|
|
Packit |
6c4009 |
*/
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/*
|
|
Packit |
6c4009 |
* Portions Copyright (c) 1996-1999 by Internet Software Consortium.
|
|
Packit |
6c4009 |
*
|
|
Packit |
6c4009 |
* Permission to use, copy, modify, and distribute this software for any
|
|
Packit |
6c4009 |
* purpose with or without fee is hereby granted, provided that the above
|
|
Packit |
6c4009 |
* copyright notice and this permission notice appear in all copies.
|
|
Packit |
6c4009 |
*
|
|
Packit |
6c4009 |
* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
|
|
Packit |
6c4009 |
* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
|
|
Packit |
6c4009 |
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
|
|
Packit |
6c4009 |
* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
|
|
Packit |
6c4009 |
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
|
|
Packit |
6c4009 |
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
|
|
Packit |
6c4009 |
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
|
|
Packit |
6c4009 |
* SOFTWARE.
|
|
Packit |
6c4009 |
*/
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
#include <sys/types.h>
|
|
Packit |
6c4009 |
#include <sys/param.h>
|
|
Packit |
6c4009 |
#include <netinet/in.h>
|
|
Packit |
6c4009 |
#include <arpa/nameser.h>
|
|
Packit |
6c4009 |
#include <netdb.h>
|
|
Packit |
6c4009 |
#include <resolv/resolv-internal.h>
|
|
Packit |
6c4009 |
#include <resolv/resolv_context.h>
|
|
Packit |
6c4009 |
#include <string.h>
|
|
Packit |
6c4009 |
#include <sys/time.h>
|
|
Packit |
6c4009 |
#include <shlib-compat.h>
|
|
Packit Service |
3b0880 |
|
|
Packit Service |
3b0880 |
#include <hp-timing.h>
|
|
Packit Service |
3b0880 |
#include <stdint.h>
|
|
Packit Service |
3b0880 |
#if HP_TIMING_AVAIL
|
|
Packit Service |
3b0880 |
# define RANDOM_BITS(Var) { uint64_t v64; HP_TIMING_NOW (v64); Var = v64; }
|
|
Packit Service |
3b0880 |
#endif
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
int
|
|
Packit |
6c4009 |
__res_context_mkquery (struct resolv_context *ctx, int op, const char *dname,
|
|
Packit |
6c4009 |
int class, int type, const unsigned char *data,
|
|
Packit |
6c4009 |
unsigned char *buf, int buflen)
|
|
Packit |
6c4009 |
{
|
|
Packit |
6c4009 |
HEADER *hp;
|
|
Packit |
6c4009 |
unsigned char *cp;
|
|
Packit |
6c4009 |
int n;
|
|
Packit |
6c4009 |
unsigned char *dnptrs[20], **dpp, **lastdnptr;
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
if (class < 0 || class > 65535 || type < 0 || type > 65535)
|
|
Packit |
6c4009 |
return -1;
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/* Initialize header fields. */
|
|
Packit |
6c4009 |
if ((buf == NULL) || (buflen < HFIXEDSZ))
|
|
Packit |
6c4009 |
return -1;
|
|
Packit |
6c4009 |
memset (buf, 0, HFIXEDSZ);
|
|
Packit |
6c4009 |
hp = (HEADER *) buf;
|
|
Packit |
6c4009 |
/* We randomize the IDs every time. The old code just incremented
|
|
Packit |
6c4009 |
by one after the initial randomization which still predictable if
|
|
Packit |
6c4009 |
the application does multiple requests. */
|
|
Packit Service |
3b0880 |
int randombits;
|
|
Packit Service |
3b0880 |
#ifdef RANDOM_BITS
|
|
Packit Service |
3b0880 |
RANDOM_BITS (randombits);
|
|
Packit Service |
3b0880 |
#else
|
|
Packit Service |
3b0880 |
struct timeval tv;
|
|
Packit Service |
3b0880 |
__gettimeofday (&tv, NULL);
|
|
Packit Service |
3b0880 |
randombits = (tv.tv_sec << 8) ^ tv.tv_usec;
|
|
Packit Service |
3b0880 |
#endif
|
|
Packit Service |
3b0880 |
|
|
Packit Service |
3b0880 |
hp->id = randombits;
|
|
Packit |
6c4009 |
hp->opcode = op;
|
|
Packit |
6c4009 |
hp->rd = (ctx->resp->options & RES_RECURSE) != 0;
|
|
Packit |
6c4009 |
hp->rcode = NOERROR;
|
|
Packit |
6c4009 |
cp = buf + HFIXEDSZ;
|
|
Packit |
6c4009 |
buflen -= HFIXEDSZ;
|
|
Packit |
6c4009 |
dpp = dnptrs;
|
|
Packit |
6c4009 |
*dpp++ = buf;
|
|
Packit |
6c4009 |
*dpp++ = NULL;
|
|
Packit |
6c4009 |
lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/* Perform opcode specific processing. */
|
|
Packit |
6c4009 |
switch (op)
|
|
Packit |
6c4009 |
{
|
|
Packit |
6c4009 |
case NS_NOTIFY_OP:
|
|
Packit |
6c4009 |
if ((buflen -= QFIXEDSZ + (data == NULL ? 0 : RRFIXEDSZ)) < 0)
|
|
Packit |
6c4009 |
return -1;
|
|
Packit |
6c4009 |
goto compose;
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
case QUERY:
|
|
Packit |
6c4009 |
if ((buflen -= QFIXEDSZ) < 0)
|
|
Packit |
6c4009 |
return -1;
|
|
Packit |
6c4009 |
compose:
|
|
Packit |
6c4009 |
n = ns_name_compress (dname, cp, buflen,
|
|
Packit |
6c4009 |
(const unsigned char **) dnptrs,
|
|
Packit |
6c4009 |
(const unsigned char **) lastdnptr);
|
|
Packit |
6c4009 |
if (n < 0)
|
|
Packit |
6c4009 |
return -1;
|
|
Packit |
6c4009 |
cp += n;
|
|
Packit |
6c4009 |
buflen -= n;
|
|
Packit |
6c4009 |
NS_PUT16 (type, cp);
|
|
Packit |
6c4009 |
NS_PUT16 (class, cp);
|
|
Packit |
6c4009 |
hp->qdcount = htons (1);
|
|
Packit |
6c4009 |
if (op == QUERY || data == NULL)
|
|
Packit |
6c4009 |
break;
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/* Make an additional record for completion domain. */
|
|
Packit |
6c4009 |
n = ns_name_compress ((char *)data, cp, buflen,
|
|
Packit |
6c4009 |
(const unsigned char **) dnptrs,
|
|
Packit |
6c4009 |
(const unsigned char **) lastdnptr);
|
|
Packit |
6c4009 |
if (__glibc_unlikely (n < 0))
|
|
Packit |
6c4009 |
return -1;
|
|
Packit |
6c4009 |
cp += n;
|
|
Packit |
6c4009 |
buflen -= n;
|
|
Packit |
6c4009 |
NS_PUT16 (T_NULL, cp);
|
|
Packit |
6c4009 |
NS_PUT16 (class, cp);
|
|
Packit |
6c4009 |
NS_PUT32 (0, cp);
|
|
Packit |
6c4009 |
NS_PUT16 (0, cp);
|
|
Packit |
6c4009 |
hp->arcount = htons (1);
|
|
Packit |
6c4009 |
break;
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
default:
|
|
Packit |
6c4009 |
return -1;
|
|
Packit |
6c4009 |
}
|
|
Packit |
6c4009 |
return cp - buf;
|
|
Packit |
6c4009 |
}
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/* Common part of res_nmkquery and res_mkquery. */
|
|
Packit |
6c4009 |
static int
|
|
Packit |
6c4009 |
context_mkquery_common (struct resolv_context *ctx,
|
|
Packit |
6c4009 |
int op, const char *dname, int class, int type,
|
|
Packit |
6c4009 |
const unsigned char *data,
|
|
Packit |
6c4009 |
unsigned char *buf, int buflen)
|
|
Packit |
6c4009 |
{
|
|
Packit |
6c4009 |
if (ctx == NULL)
|
|
Packit |
6c4009 |
return -1;
|
|
Packit |
6c4009 |
int result = __res_context_mkquery
|
|
Packit |
6c4009 |
(ctx, op, dname, class, type, data, buf, buflen);
|
|
Packit |
6c4009 |
if (result >= 2)
|
|
Packit |
6c4009 |
memcpy (&ctx->resp->id, buf, 2);
|
|
Packit |
6c4009 |
__resolv_context_put (ctx);
|
|
Packit |
6c4009 |
return result;
|
|
Packit |
6c4009 |
}
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/* Form all types of queries. Returns the size of the result or -1 on
|
|
Packit |
6c4009 |
error.
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
STATP points to an initialized resolver state. OP is the opcode of
|
|
Packit |
6c4009 |
the query. DNAME is the domain. CLASS and TYPE are the DNS query
|
|
Packit |
6c4009 |
class and type. DATA can be NULL; otherwise, it is a pointer to a
|
|
Packit |
6c4009 |
domain name which is included in the generated packet (if op ==
|
|
Packit |
6c4009 |
NS_NOTIFY_OP). BUF must point to the out buffer of BUFLEN bytes.
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
DATALEN and NEWRR_IN are currently ignored. */
|
|
Packit |
6c4009 |
int
|
|
Packit |
6c4009 |
res_nmkquery (res_state statp, int op, const char *dname,
|
|
Packit |
6c4009 |
int class, int type,
|
|
Packit |
6c4009 |
const unsigned char *data, int datalen,
|
|
Packit |
6c4009 |
const unsigned char *newrr_in,
|
|
Packit |
6c4009 |
unsigned char *buf, int buflen)
|
|
Packit |
6c4009 |
{
|
|
Packit |
6c4009 |
return context_mkquery_common
|
|
Packit |
6c4009 |
(__resolv_context_get_override (statp),
|
|
Packit |
6c4009 |
op, dname, class, type, data, buf, buflen);
|
|
Packit |
6c4009 |
}
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
int
|
|
Packit |
6c4009 |
res_mkquery (int op, const char *dname, int class, int type,
|
|
Packit |
6c4009 |
const unsigned char *data, int datalen,
|
|
Packit |
6c4009 |
const unsigned char *newrr_in,
|
|
Packit |
6c4009 |
unsigned char *buf, int buflen)
|
|
Packit |
6c4009 |
{
|
|
Packit |
6c4009 |
return context_mkquery_common
|
|
Packit |
6c4009 |
(__resolv_context_get_preinit (),
|
|
Packit |
6c4009 |
op, dname, class, type, data, buf, buflen);
|
|
Packit |
6c4009 |
}
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/* Create an OPT resource record. Return the length of the final
|
|
Packit |
6c4009 |
packet, or -1 on error.
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
STATP must be an initialized resolver state. N0 is the current
|
|
Packit |
6c4009 |
number of bytes of the packet (already written to BUF by the
|
|
Packit |
6c4009 |
aller). BUF is the packet being constructed. The array it
|
|
Packit |
6c4009 |
pointers to must be BUFLEN bytes long. ANSLEN is the advertised
|
|
Packit |
6c4009 |
EDNS buffer size (to be included in the OPT resource record). */
|
|
Packit |
6c4009 |
int
|
|
Packit |
6c4009 |
__res_nopt (struct resolv_context *ctx,
|
|
Packit |
6c4009 |
int n0, unsigned char *buf, int buflen, int anslen)
|
|
Packit |
6c4009 |
{
|
|
Packit |
6c4009 |
uint16_t flags = 0;
|
|
Packit |
6c4009 |
HEADER *hp = (HEADER *) buf;
|
|
Packit |
6c4009 |
unsigned char *cp = buf + n0;
|
|
Packit |
6c4009 |
unsigned char *ep = buf + buflen;
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
if ((ep - cp) < 1 + RRFIXEDSZ)
|
|
Packit |
6c4009 |
return -1;
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/* Add the root label. */
|
|
Packit |
6c4009 |
*cp++ = 0;
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
NS_PUT16 (T_OPT, cp); /* Record type. */
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
/* Lowering the advertised buffer size based on the actual
|
|
Packit |
6c4009 |
answer buffer size is desirable because the server will
|
|
Packit |
6c4009 |
minimize the reply to fit into the UDP packet (and A
|
|
Packit |
6c4009 |
non-minimal response might not fit the buffer).
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
The RESOLV_EDNS_BUFFER_SIZE limit could still result in TCP
|
|
Packit |
6c4009 |
fallback and a non-minimal response which has to be
|
|
Packit |
6c4009 |
hard-truncated in the stub resolver, but this is price to
|
|
Packit |
6c4009 |
pay for avoiding fragmentation. (This issue does not
|
|
Packit |
6c4009 |
affect the nss_dns functions because they use the stub
|
|
Packit |
6c4009 |
resolver in such a way that it allocates a properly sized
|
|
Packit |
6c4009 |
response buffer.) */
|
|
Packit |
6c4009 |
{
|
|
Packit |
6c4009 |
uint16_t buffer_size;
|
|
Packit |
6c4009 |
if (anslen < 512)
|
|
Packit |
6c4009 |
buffer_size = 512;
|
|
Packit |
6c4009 |
else if (anslen > RESOLV_EDNS_BUFFER_SIZE)
|
|
Packit |
6c4009 |
buffer_size = RESOLV_EDNS_BUFFER_SIZE;
|
|
Packit |
6c4009 |
else
|
|
Packit |
6c4009 |
buffer_size = anslen;
|
|
Packit |
6c4009 |
NS_PUT16 (buffer_size, cp);
|
|
Packit |
6c4009 |
}
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
*cp++ = NOERROR; /* Extended RCODE. */
|
|
Packit |
6c4009 |
*cp++ = 0; /* EDNS version. */
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
if (ctx->resp->options & RES_USE_DNSSEC)
|
|
Packit |
6c4009 |
flags |= NS_OPT_DNSSEC_OK;
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
NS_PUT16 (flags, cp);
|
|
Packit |
6c4009 |
NS_PUT16 (0, cp); /* RDATA length (no options are preent). */
|
|
Packit |
6c4009 |
hp->arcount = htons (ntohs (hp->arcount) + 1);
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
return cp - buf;
|
|
Packit |
6c4009 |
}
|
|
Packit |
6c4009 |
|
|
Packit |
6c4009 |
#if SHLIB_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_2)
|
|
Packit |
6c4009 |
# undef res_mkquery
|
|
Packit |
6c4009 |
weak_alias (__res_mkquery, res_mkquery);
|
|
Packit |
6c4009 |
#endif
|