1/* $NetBSD: res_mkquery.c,v 1.17 2024/02/10 08:36:04 andvar 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 1.17 2024/02/10 08:36:04 andvar Exp $"); 76#endif 77#endif /* LIBC_SCCS and not lint */ 78 79#include "port_before.h" 80 81#include "namespace.h" 82#include <sys/types.h> 83#include <sys/param.h> 84#include <netinet/in.h> 85#include <arpa/nameser.h> 86#include <assert.h> 87#include <netdb.h> 88#include <resolv.h> 89#include <stdio.h> 90#include <string.h> 91#include "port_after.h" 92 93#if 0 94#ifdef __weak_alias 95__weak_alias(res_nmkquery,_res_nmkquery) 96__weak_alias(res_nopt,_res_nopt) 97#endif 98#endif 99 100/* Options. Leave them on. */ 101#ifndef DEBUG 102#define DEBUG 103#endif 104 105extern const char *_res_opcodes[]; 106 107/*% 108 * Form all types of queries. 109 * Returns the size of the result or -1. 110 */ 111int 112res_nmkquery(res_state statp, 113 int op, /*!< opcode of query */ 114 const char *dname, /*!< domain name */ 115 int class, int type, /*!< class and type of query */ 116 const u_char *data, /*!< resource record data */ 117 int datalen, /*!< length of data */ 118 const u_char *newrr_in, /*!< new rr for modify or append */ 119 u_char *buf, /*!< buffer to put query */ 120 int buflen) /*!< size of buffer */ 121{ 122 register HEADER *hp; 123 register u_char *cp, *ep; 124 register int n; 125 u_char *dnptrs[20], **dpp, **lastdnptr; 126 127 UNUSED(newrr_in); 128 129#ifdef DEBUG 130 if (statp->options & RES_DEBUG) 131 printf(";; res_nmkquery(%s, %s, %s, %s)\n", 132 _res_opcodes[op], dname, p_class(class), p_type(type)); 133#endif 134 /* 135 * Initialize header fields. 136 */ 137 if ((buf == NULL) || (buflen < HFIXEDSZ)) 138 return (-1); 139 memset(buf, 0, HFIXEDSZ); 140 hp = (HEADER *)(void *)buf; 141 statp->id = res_nrandomid(statp); 142 hp->id = htons(statp->id); 143 hp->opcode = op; 144 hp->rd = (statp->options & RES_RECURSE) != 0U; 145 hp->ad = (statp->options & RES_USE_DNSSEC) != 0U; 146 hp->rcode = NOERROR; 147 cp = buf + HFIXEDSZ; 148 ep = buf + buflen; 149 dpp = dnptrs; 150 *dpp++ = buf; 151 *dpp++ = NULL; 152 lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0]; 153 /* 154 * perform opcode specific processing 155 */ 156 switch (op) { 157 case QUERY: /*FALLTHROUGH*/ 158 case NS_NOTIFY_OP: 159 if (ep - cp < QFIXEDSZ) 160 return (-1); 161 if ((n = dn_comp(dname, cp, (int)(ep - cp - QFIXEDSZ), dnptrs, 162 lastdnptr)) < 0) 163 return (-1); 164 cp += n; 165 ns_put16(type, cp); 166 cp += INT16SZ; 167 ns_put16(class, cp); 168 cp += INT16SZ; 169 hp->qdcount = htons(1); 170 if (op == QUERY || data == NULL) 171 break; 172 /* 173 * Make an additional record for completion domain. 174 */ 175 if ((ep - cp) < RRFIXEDSZ) 176 return (-1); 177 n = dn_comp((const char *)data, cp, (int)(ep - cp - RRFIXEDSZ), 178 dnptrs, lastdnptr); 179 if (n < 0) 180 return (-1); 181 cp += n; 182 ns_put16(T_NULL, cp); 183 cp += INT16SZ; 184 ns_put16(class, cp); 185 cp += INT16SZ; 186 ns_put32(0, cp); 187 cp += INT32SZ; 188 ns_put16(0, cp); 189 cp += INT16SZ; 190 hp->arcount = htons(1); 191 break; 192 193 case IQUERY: 194 /* 195 * Initialize answer section 196 */ 197 if (ep - cp < 1 + RRFIXEDSZ + datalen) 198 return (-1); 199 *cp++ = '\0'; /*%< no domain name */ 200 ns_put16(type, cp); 201 cp += INT16SZ; 202 ns_put16(class, cp); 203 cp += INT16SZ; 204 ns_put32(0, cp); 205 cp += INT32SZ; 206 ns_put16(datalen, cp); 207 cp += INT16SZ; 208 if (datalen) { 209 memcpy(cp, data, (size_t)datalen); 210 cp += datalen; 211 } 212 hp->ancount = htons(1); 213 break; 214 215 default: 216 return (-1); 217 } 218 _DIAGASSERT(__type_fit(int, cp - buf)); 219 return (int)(cp - buf); 220} 221 222#ifdef RES_USE_EDNS0 223/* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */ 224 225int 226res_nopt(res_state statp, 227 int n0, /*%< current offset in buffer */ 228 u_char *buf, /*%< buffer to put query */ 229 int buflen, /*%< size of buffer */ 230 int anslen) /*%< UDP answer buffer size */ 231{ 232 register HEADER *hp; 233 register u_char *cp, *ep; 234 u_int16_t flags = 0; 235 236#ifdef DEBUG 237 if ((statp->options & RES_DEBUG) != 0U) 238 printf(";; res_nopt()\n"); 239#endif 240 241 hp = (HEADER *)(void *)buf; 242 cp = buf + n0; 243 ep = buf + buflen; 244 245 if ((ep - cp) < 1 + RRFIXEDSZ) 246 return (-1); 247 248 *cp++ = 0; /*%< "." */ 249 ns_put16(ns_t_opt, cp); /*%< TYPE */ 250 cp += INT16SZ; 251 if (anslen > 0xffff) 252 anslen = 0xffff; 253 ns_put16(anslen, cp); /*%< CLASS = UDP payload size */ 254 cp += INT16SZ; 255 *cp++ = NOERROR; /*%< extended RCODE */ 256 *cp++ = 0; /*%< EDNS version */ 257 258 if (statp->options & RES_USE_DNSSEC) { 259#ifdef DEBUG 260 if (statp->options & RES_DEBUG) 261 printf(";; res_opt()... ENDS0 DNSSEC\n"); 262#endif 263 flags |= NS_OPT_DNSSEC_OK; 264 } 265 ns_put16(flags, cp); 266 cp += INT16SZ; 267 268 ns_put16(0U, cp); /*%< RDLEN */ 269 cp += INT16SZ; 270 271 hp->arcount = htons(ntohs(hp->arcount) + 1); 272 273 _DIAGASSERT(__type_fit(int, cp - buf)); 274 return (int)(cp - buf); 275} 276 277/* 278 * Construct variable data (RDATA) block for OPT pseudo-RR, append it 279 * to the buffer, then update the RDLEN field (previously set to zero by 280 * res_nopt()) with the new RDATA length. 281 */ 282int 283res_nopt_rdata(res_state statp, 284 int n0, /*%< current offset in buffer */ 285 u_char *buf, /*%< buffer to put query */ 286 int buflen, /*%< size of buffer */ 287 u_char *rdata, /*%< ptr to start of opt rdata */ 288 u_short code, /*%< OPTION-CODE */ 289 u_short len, /*%< OPTION-LENGTH */ 290 u_char *data) /*%< OPTION_DATA */ 291{ 292 register u_char *cp, *ep; 293 294#ifdef DEBUG 295 if ((statp->options & RES_DEBUG) != 0U) 296 printf(";; res_nopt_rdata()\n"); 297#endif 298 299 cp = buf + n0; 300 ep = buf + buflen; 301 302 if ((ep - cp) < (4 + len)) 303 return (-1); 304 305 if (rdata < (buf + 2) || rdata >= ep) 306 return (-1); 307 308 ns_put16(code, cp); 309 cp += INT16SZ; 310 311 ns_put16(len, cp); 312 cp += INT16SZ; 313 314 memcpy(cp, data, (size_t)len); 315 cp += len; 316 317 _DIAGASSERT(__type_fit(u_short, cp - rdata)); 318 len = (u_short)(cp - rdata); 319 ns_put16(len, rdata - 2); /* Update RDLEN field */ 320 321 _DIAGASSERT(__type_fit(int, cp - buf)); 322 return (int)(cp - buf); 323} 324#endif 325 326/*! \file */ 327