res_mkquery.c revision 270838
1/* 2 * Portions Copyright (C) 2004, 2005, 2008 Internet Systems Consortium, Inc. ("ISC") 3 * Portions Copyright (C) 1996, 1997, 1988, 1999, 2001, 2003 Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and/or distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 15 * PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18/* 19 * Copyright (c) 1985, 1993 20 * The Regents of the University of California. All rights reserved. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 4. Neither the name of the University nor the names of its contributors 31 * may be used to endorse or promote products derived from this software 32 * without specific prior written permission. 33 * 34 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 37 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 44 * SUCH DAMAGE. 45 */ 46 47/* 48 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 49 * 50 * Permission to use, copy, modify, and distribute this software for any 51 * purpose with or without fee is hereby granted, provided that the above 52 * copyright notice and this permission notice appear in all copies, and that 53 * the name of Digital Equipment Corporation not be used in advertising or 54 * publicity pertaining to distribution of the document or software without 55 * specific, written prior permission. 56 * 57 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 58 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 59 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 60 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 61 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 62 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 63 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 64 * SOFTWARE. 65 */ 66 67#if defined(LIBC_SCCS) && !defined(lint) 68static const char sccsid[] = "@(#)res_mkquery.c 8.1 (Berkeley) 6/4/93"; 69static const char rcsid[] = "$Id: res_mkquery.c,v 1.10 2008/12/11 09:59:00 marka Exp $"; 70#endif /* LIBC_SCCS and not lint */ 71#include <sys/cdefs.h> 72__FBSDID("$FreeBSD: stable/10/lib/libc/resolv/res_mkquery.c 270838 2014-08-30 10:16:25Z ume $"); 73 74#include "port_before.h" 75#include <sys/types.h> 76#include <sys/param.h> 77#include <netinet/in.h> 78#include <arpa/nameser.h> 79#include <netdb.h> 80#include <resolv.h> 81#include <stdio.h> 82#include <string.h> 83#include "port_after.h" 84 85/* Options. Leave them on. */ 86#define DEBUG 87 88extern const char *_res_opcodes[]; 89 90/*% 91 * Form all types of queries. 92 * Returns the size of the result or -1. 93 */ 94int 95res_nmkquery(res_state statp, 96 int op, /*!< opcode of query */ 97 const char *dname, /*!< domain name */ 98 int class, int type, /*!< class and type of query */ 99 const u_char *data, /*!< resource record data */ 100 int datalen, /*!< length of data */ 101 const u_char *newrr_in, /*!< new rr for modify or append */ 102 u_char *buf, /*!< buffer to put query */ 103 int buflen) /*!< size of buffer */ 104{ 105 HEADER *hp; 106 u_char *cp, *ep; 107 int n; 108 u_char *dnptrs[20], **dpp, **lastdnptr; 109 110 UNUSED(newrr_in); 111 112#ifdef DEBUG 113 if (statp->options & RES_DEBUG) 114 printf(";; res_nmkquery(%s, %s, %s, %s)\n", 115 _res_opcodes[op], dname, p_class(class), p_type(type)); 116#endif 117 /* 118 * Initialize header fields. 119 */ 120 if ((buf == NULL) || (buflen < HFIXEDSZ)) 121 return (-1); 122 memset(buf, 0, HFIXEDSZ); 123 hp = (HEADER *) buf; 124 statp->id = res_nrandomid(statp); 125 hp->id = htons(statp->id); 126 hp->opcode = op; 127 hp->rd = (statp->options & RES_RECURSE) != 0U; 128 hp->rcode = NOERROR; 129 cp = buf + HFIXEDSZ; 130 ep = buf + buflen; 131 dpp = dnptrs; 132 *dpp++ = buf; 133 *dpp++ = NULL; 134 lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0]; 135 /* 136 * perform opcode specific processing 137 */ 138 switch (op) { 139 case QUERY: /*FALLTHROUGH*/ 140 case NS_NOTIFY_OP: 141 if (ep - cp < QFIXEDSZ) 142 return (-1); 143 if ((n = dn_comp(dname, cp, ep - cp - QFIXEDSZ, dnptrs, 144 lastdnptr)) < 0) 145 return (-1); 146 cp += n; 147 ns_put16(type, cp); 148 cp += INT16SZ; 149 ns_put16(class, cp); 150 cp += INT16SZ; 151 hp->qdcount = htons(1); 152 if (op == QUERY || data == NULL) 153 break; 154 /* 155 * Make an additional record for completion domain. 156 */ 157 if ((ep - cp) < RRFIXEDSZ) 158 return (-1); 159 n = dn_comp((const char *)data, cp, ep - cp - RRFIXEDSZ, 160 dnptrs, lastdnptr); 161 if (n < 0) 162 return (-1); 163 cp += n; 164 ns_put16(T_NULL, cp); 165 cp += INT16SZ; 166 ns_put16(class, cp); 167 cp += INT16SZ; 168 ns_put32(0, cp); 169 cp += INT32SZ; 170 ns_put16(0, cp); 171 cp += INT16SZ; 172 hp->arcount = htons(1); 173 break; 174 175 case IQUERY: 176 /* 177 * Initialize answer section 178 */ 179 if (ep - cp < 1 + RRFIXEDSZ + datalen) 180 return (-1); 181 *cp++ = '\0'; /*%< no domain name */ 182 ns_put16(type, cp); 183 cp += INT16SZ; 184 ns_put16(class, cp); 185 cp += INT16SZ; 186 ns_put32(0, cp); 187 cp += INT32SZ; 188 ns_put16(datalen, cp); 189 cp += INT16SZ; 190 if (datalen) { 191 memcpy(cp, data, datalen); 192 cp += datalen; 193 } 194 hp->ancount = htons(1); 195 break; 196 197 default: 198 return (-1); 199 } 200 return (cp - buf); 201} 202 203#ifdef RES_USE_EDNS0 204/* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */ 205 206int 207res_nopt(res_state statp, 208 int n0, /*%< current offset in buffer */ 209 u_char *buf, /*%< buffer to put query */ 210 int buflen, /*%< size of buffer */ 211 int anslen) /*%< UDP answer buffer size */ 212{ 213 HEADER *hp; 214 u_char *cp, *ep; 215 u_int16_t flags = 0; 216 217#ifdef DEBUG 218 if ((statp->options & RES_DEBUG) != 0U) 219 printf(";; res_nopt()\n"); 220#endif 221 222 hp = (HEADER *) buf; 223 cp = buf + n0; 224 ep = buf + buflen; 225 226 if ((ep - cp) < 1 + RRFIXEDSZ) 227 return (-1); 228 229 *cp++ = 0; /*%< "." */ 230 ns_put16(ns_t_opt, cp); /*%< TYPE */ 231 cp += INT16SZ; 232 if (anslen > 0xffff) 233 anslen = 0xffff; /* limit to 16bit value */ 234 ns_put16(anslen & 0xffff, cp); /*%< CLASS = UDP payload size */ 235 cp += INT16SZ; 236 *cp++ = NOERROR; /*%< extended RCODE */ 237 *cp++ = 0; /*%< EDNS version */ 238 239 if (statp->options & RES_USE_DNSSEC) { 240#ifdef DEBUG 241 if (statp->options & RES_DEBUG) 242 printf(";; res_opt()... ENDS0 DNSSEC\n"); 243#endif 244 flags |= NS_OPT_DNSSEC_OK; 245 } 246 ns_put16(flags, cp); 247 cp += INT16SZ; 248 249 ns_put16(0U, cp); /*%< RDLEN */ 250 cp += INT16SZ; 251 252 hp->arcount = htons(ntohs(hp->arcount) + 1); 253 254 return (cp - buf); 255} 256 257/* 258 * Construct variable data (RDATA) block for OPT psuedo-RR, append it 259 * to the buffer, then update the RDLEN field (previously set to zero by 260 * res_nopt()) with the new RDATA length. 261 */ 262int 263res_nopt_rdata(res_state statp, 264 int n0, /*%< current offset in buffer */ 265 u_char *buf, /*%< buffer to put query */ 266 int buflen, /*%< size of buffer */ 267 u_char *rdata, /*%< ptr to start of opt rdata */ 268 u_short code, /*%< OPTION-CODE */ 269 u_short len, /*%< OPTION-LENGTH */ 270 u_char *data) /*%< OPTION_DATA */ 271{ 272 register u_char *cp, *ep; 273 274#ifdef DEBUG 275 if ((statp->options & RES_DEBUG) != 0U) 276 printf(";; res_nopt_rdata()\n"); 277#endif 278 279 cp = buf + n0; 280 ep = buf + buflen; 281 282 if ((ep - cp) < (4 + len)) 283 return (-1); 284 285 if (rdata < (buf + 2) || rdata >= ep) 286 return (-1); 287 288 ns_put16(code, cp); 289 cp += INT16SZ; 290 291 ns_put16(len, cp); 292 cp += INT16SZ; 293 294 memcpy(cp, data, len); 295 cp += len; 296 297 len = cp - rdata; 298 ns_put16(len, rdata - 2); /* Update RDLEN field */ 299 300 return (cp - buf); 301} 302#endif 303 304/*! \file */ 305