1/* $NetBSD: res_mkquery.c,v 1.16 2017/09/28 23:32:01 christos Exp $ */ 2 3/* 4 * Portions Copyright (C) 2004, 2005, 2008 Internet Systems Consortium, Inc. ("ISC") 5 * Portions Copyright (C) 1996, 1997, 1988, 1999, 2001, 2003 Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17 * PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20/* 21 * Copyright (c) 1985, 1993 22 * The Regents of the University of California. All rights reserved. 23 * 24 * Redistribution and use in source and binary forms, with or without 25 * modification, are permitted provided that the following conditions 26 * are met: 27 * 1. Redistributions of source code must retain the above copyright 28 * notice, this list of conditions and the following disclaimer. 29 * 2. Redistributions in binary form must reproduce the above copyright 30 * notice, this list of conditions and the following disclaimer in the 31 * documentation and/or other materials provided with the distribution. 32 * 3. Neither the name of the University nor the names of its contributors 33 * may be used to endorse or promote products derived from this software 34 * without specific prior written permission. 35 * 36 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 37 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 39 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 40 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 41 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 42 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 43 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 44 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 45 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 46 * SUCH DAMAGE. 47 */ 48 49/* 50 * Portions Copyright (c) 1993 by Digital Equipment Corporation. 51 * 52 * Permission to use, copy, modify, and distribute this software for any 53 * purpose with or without fee is hereby granted, provided that the above 54 * copyright notice and this permission notice appear in all copies, and that 55 * the name of Digital Equipment Corporation not be used in advertising or 56 * publicity pertaining to distribution of the document or software without 57 * specific, written prior permission. 58 * 59 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL 60 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES 61 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT 62 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 63 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 64 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 65 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 66 * SOFTWARE. 67 */ 68 69#include <sys/cdefs.h> 70#if defined(LIBC_SCCS) && !defined(lint) 71#ifdef notdef 72static const char sccsid[] = "@(#)res_mkquery.c 8.1 (Berkeley) 6/4/93"; 73static const char rcsid[] = "Id: res_mkquery.c,v 1.10 2008/12/11 09:59:00 marka Exp"; 74#else 75__RCSID("$NetBSD: res_mkquery.c,v 1.16 2017/09/28 23:32:01 christos Exp $"); 76#endif 77#endif /* LIBC_SCCS and not lint */ 78 79#include "port_before.h" 80 81#include <sys/types.h> 82#include <sys/param.h> 83#include <netinet/in.h> 84#include <arpa/nameser.h> 85#include <assert.h> 86#include <netdb.h> 87#include <resolv.h> 88#include <stdio.h> 89#include <string.h> 90#include "port_after.h" 91 92/* Options. Leave them on. */ 93//#define DEBUG 94 95extern const char *_res_opcodes[]; 96 97/*% 98 * Form all types of queries. 99 * Returns the size of the result or -1. 100 */ 101int 102res_nmkquery(res_state statp, 103 int op, /*!< opcode of query */ 104 const char *dname, /*!< domain name */ 105 int class, int type, /*!< class and type of query */ 106 const u_char *data, /*!< resource record data */ 107 int datalen, /*!< length of data */ 108 const u_char *newrr_in, /*!< new rr for modify or append */ 109 u_char *buf, /*!< buffer to put query */ 110 int buflen) /*!< size of buffer */ 111{ 112 register HEADER *hp; 113 register u_char *cp, *ep; 114 register int n; 115 u_char *dnptrs[20], **dpp, **lastdnptr; 116 117 UNUSED(newrr_in); 118 119#ifdef DEBUG 120 if (statp->options & RES_DEBUG) 121 printf(";; res_nmkquery(%s, %s, %s, %s)\n", 122 _res_opcodes[op], dname, p_class(class), p_type(type)); 123#endif 124 /* 125 * Initialize header fields. 126 */ 127 if ((buf == NULL) || (buflen < HFIXEDSZ)) 128 return (-1); 129 memset(buf, 0, HFIXEDSZ); 130 hp = (HEADER *)(void *)buf; 131 statp->id = res_nrandomid(statp); 132 hp->id = htons(statp->id); 133 hp->opcode = op; 134 hp->rd = (statp->options & RES_RECURSE) != 0U; 135 hp->ad = (statp->options & RES_USE_DNSSEC) != 0U; 136 hp->rcode = NOERROR; 137 cp = buf + HFIXEDSZ; 138 ep = buf + buflen; 139 dpp = dnptrs; 140 *dpp++ = buf; 141 *dpp++ = NULL; 142 lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0]; 143 /* 144 * perform opcode specific processing 145 */ 146 switch (op) { 147 case QUERY: /*FALLTHROUGH*/ 148 case NS_NOTIFY_OP: 149 if (ep - cp < QFIXEDSZ) 150 return (-1); 151 if ((n = dn_comp(dname, cp, (int)(ep - cp - QFIXEDSZ), dnptrs, 152 lastdnptr)) < 0) 153 return (-1); 154 cp += n; 155 ns_put16(type, cp); 156 cp += INT16SZ; 157 ns_put16(class, cp); 158 cp += INT16SZ; 159 hp->qdcount = htons(1); 160 if (op == QUERY || data == NULL) 161 break; 162 /* 163 * Make an additional record for completion domain. 164 */ 165 if ((ep - cp) < RRFIXEDSZ) 166 return (-1); 167 n = dn_comp((const char *)data, cp, (int)(ep - cp - RRFIXEDSZ), 168 dnptrs, lastdnptr); 169 if (n < 0) 170 return (-1); 171 cp += n; 172 ns_put16(T_NULL, cp); 173 cp += INT16SZ; 174 ns_put16(class, cp); 175 cp += INT16SZ; 176 ns_put32(0, cp); 177 cp += INT32SZ; 178 ns_put16(0, cp); 179 cp += INT16SZ; 180 hp->arcount = htons(1); 181 break; 182 183 case IQUERY: 184 /* 185 * Initialize answer section 186 */ 187 if (ep - cp < 1 + RRFIXEDSZ + datalen) 188 return (-1); 189 *cp++ = '\0'; /*%< no domain name */ 190 ns_put16(type, cp); 191 cp += INT16SZ; 192 ns_put16(class, cp); 193 cp += INT16SZ; 194 ns_put32(0, cp); 195 cp += INT32SZ; 196 ns_put16(datalen, cp); 197 cp += INT16SZ; 198 if (datalen) { 199 memcpy(cp, data, (size_t)datalen); 200 cp += datalen; 201 } 202 hp->ancount = htons(1); 203 break; 204 205 default: 206 return (-1); 207 } 208 assert(INT_MIN <= (cp - buf) && (cp - buf) <= INT_MAX); 209 return (int)(cp - buf); 210} 211 212#ifdef RES_USE_EDNS0 213/* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */ 214 215int 216res_nopt(res_state statp, 217 int n0, /*%< current offset in buffer */ 218 u_char *buf, /*%< buffer to put query */ 219 int buflen, /*%< size of buffer */ 220 int anslen) /*%< UDP answer buffer size */ 221{ 222 register HEADER *hp; 223 register u_char *cp, *ep; 224 u_int16_t flags = 0; 225 226#ifdef DEBUG 227 if ((statp->options & RES_DEBUG) != 0U) 228 printf(";; res_nopt()\n"); 229#endif 230 231 hp = (HEADER *)(void *)buf; 232 cp = buf + n0; 233 ep = buf + buflen; 234 235 if ((ep - cp) < 1 + RRFIXEDSZ) 236 return (-1); 237 238 *cp++ = 0; /*%< "." */ 239 ns_put16(ns_t_opt, cp); /*%< TYPE */ 240 cp += INT16SZ; 241 if (anslen > 0xffff) 242 anslen = 0xffff; 243 ns_put16(anslen, cp); /*%< CLASS = UDP payload size */ 244 cp += INT16SZ; 245 *cp++ = NOERROR; /*%< extended RCODE */ 246 *cp++ = 0; /*%< EDNS version */ 247 248 if (statp->options & RES_USE_DNSSEC) { 249#ifdef DEBUG 250 if (statp->options & RES_DEBUG) 251 printf(";; res_opt()... ENDS0 DNSSEC\n"); 252#endif 253 flags |= NS_OPT_DNSSEC_OK; 254 } 255 ns_put16(flags, cp); 256 cp += INT16SZ; 257 258 ns_put16(0U, cp); /*%< RDLEN */ 259 cp += INT16SZ; 260 261 hp->arcount = htons(ntohs(hp->arcount) + 1); 262 263 assert(INT_MIN <= (cp - buf) && (cp - buf) <= INT_MAX); 264 return (int)(cp - buf); 265} 266 267/* 268 * Construct variable data (RDATA) block for OPT psuedo-RR, append it 269 * to the buffer, then update the RDLEN field (previously set to zero by 270 * res_nopt()) with the new RDATA length. 271 */ 272int 273res_nopt_rdata(res_state statp, 274 int n0, /*%< current offset in buffer */ 275 u_char *buf, /*%< buffer to put query */ 276 int buflen, /*%< size of buffer */ 277 u_char *rdata, /*%< ptr to start of opt rdata */ 278 u_short code, /*%< OPTION-CODE */ 279 u_short len, /*%< OPTION-LENGTH */ 280 u_char *data) /*%< OPTION_DATA */ 281{ 282 register u_char *cp, *ep; 283 284#ifdef DEBUG 285 if ((statp->options & RES_DEBUG) != 0U) 286 printf(";; res_nopt_rdata()\n"); 287#endif 288 289 cp = buf + n0; 290 ep = buf + buflen; 291 292 if ((ep - cp) < (4 + len)) 293 return (-1); 294 295 if (rdata < (buf + 2) || rdata >= ep) 296 return (-1); 297 298 ns_put16(code, cp); 299 cp += INT16SZ; 300 301 ns_put16(len, cp); 302 cp += INT16SZ; 303 304 memcpy(cp, data, (size_t)len); 305 cp += len; 306 307 assert(0 <= (cp - rdata) && (cp - rdata) <= USHRT_MAX); 308 len = (u_short)(cp - rdata); 309 ns_put16(len, rdata - 2); /* Update RDLEN field */ 310 311 assert(INT_MIN <= (cp - buf) && (cp - buf) <= INT_MAX); 312 return (int)(cp - buf); 313} 314#endif 315 316/*! \file */ 317