1 /*- 2 * SPDX-License-Identifier: ISC 3 * 4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (c) 1995-1999 by Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and 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 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #include "port_before.h" 21 22 #include <sys/param.h> 23 #include <sys/socket.h> 24 #include <sys/time.h> 25 26 #include <netinet/in.h> 27 #include <arpa/inet.h> 28 #include <arpa/nameser.h> 29 30 #include <ctype.h> 31 #include <netdb.h> 32 #include <resolv.h> 33 #include <res_update.h> 34 #include <stdio.h> 35 #include <stdlib.h> 36 #include <string.h> 37 #include <unistd.h> 38 39 #include "port_after.h" 40 41 const char *_res_opcodes[] = { 42 "QUERY", 43 "IQUERY", 44 "CQUERYM", 45 "CQUERYU", /*%< experimental */ 46 "NOTIFY", /*%< experimental */ 47 "UPDATE", 48 "6", 49 "7", 50 "8", 51 "9", 52 "10", 53 "11", 54 "12", 55 "13", 56 "ZONEINIT", 57 "ZONEREF", 58 }; 59 60 #ifdef BIND_UPDATE 61 const char *_res_sectioncodes[] = { 62 "ZONE", 63 "PREREQUISITES", 64 "UPDATE", 65 "ADDITIONAL", 66 }; 67 #endif 68 69 #ifndef __BIND_NOSTATIC 70 71 /* Proto. */ 72 73 int res_ourserver_p(const res_state, const struct sockaddr_in *); 74 75 __noinline int 76 res_init(void) { 77 extern int __res_vinit(res_state, int); 78 res_state statp = &_res; 79 80 /* 81 * These three fields used to be statically initialized. This made 82 * it hard to use this code in a shared library. It is necessary, 83 * now that we're doing dynamic initialization here, that we preserve 84 * the old semantics: if an application modifies one of these three 85 * fields of _res before res_init() is called, res_init() will not 86 * alter them. Of course, if an application is setting them to 87 * _zero_ before calling res_init(), hoping to override what used 88 * to be the static default, we can't detect it and unexpected results 89 * will follow. Zero for any of these fields would make no sense, 90 * so one can safely assume that the applications were already getting 91 * unexpected results. 92 * 93 * _res.options is tricky since some apps were known to diddle the bits 94 * before res_init() was first called. We can't replicate that semantic 95 * with dynamic initialization (they may have turned bits off that are 96 * set in RES_DEFAULT). Our solution is to declare such applications 97 * "broken". They could fool us by setting RES_INIT but none do (yet). 98 */ 99 if (!statp->retrans) 100 statp->retrans = RES_TIMEOUT; 101 if (!statp->retry) 102 statp->retry = RES_DFLRETRY; 103 if (!(statp->options & RES_INIT)) 104 statp->options = RES_DEFAULT; 105 106 return (__res_vinit(statp, 1)); 107 } 108 109 void 110 p_query(const u_char *msg) { 111 fp_query(msg, stdout); 112 } 113 114 void 115 fp_query(const u_char *msg, FILE *file) { 116 fp_nquery(msg, PACKETSZ, file); 117 } 118 119 void 120 fp_nquery(const u_char *msg, int len, FILE *file) { 121 res_state statp = &_res; 122 if ((statp->options & RES_INIT) == 0U && res_init() == -1) 123 return; 124 125 res_pquery(statp, msg, len, file); 126 } 127 128 int 129 res_mkquery(int op, /*!< opcode of query */ 130 const char *dname, /*!< domain name */ 131 int class, int type, /*!< class and type of query */ 132 const u_char *data, /*!< resource record data */ 133 int datalen, /*!< length of data */ 134 const u_char *newrr_in, /*!< new rr for modify or append */ 135 u_char *buf, /*!< buffer to put query */ 136 int buflen) /*!< size of buffer */ 137 { 138 res_state statp = &_res; 139 if ((statp->options & RES_INIT) == 0U && res_init() == -1) { 140 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 141 return (-1); 142 } 143 return (res_nmkquery(statp, op, dname, class, type, 144 data, datalen, 145 newrr_in, buf, buflen)); 146 } 147 148 int 149 res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) { 150 res_state statp = &_res; 151 if ((statp->options & RES_INIT) == 0U && res_init() == -1) { 152 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 153 return (-1); 154 } 155 156 return (res_nmkupdate(statp, rrecp_in, buf, buflen)); 157 } 158 159 int 160 res_query(const char *name, /*!< domain name */ 161 int class, int type, /*!< class and type of query */ 162 u_char *answer, /*!< buffer to put answer */ 163 int anslen) /*!< size of answer buffer */ 164 { 165 res_state statp = &_res; 166 if ((statp->options & RES_INIT) == 0U && res_init() == -1) { 167 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 168 return (-1); 169 } 170 return (res_nquery(statp, name, class, type, answer, anslen)); 171 } 172 173 #ifndef _LIBC 174 void 175 res_send_setqhook(res_send_qhook hook) { 176 _res.qhook = hook; 177 } 178 179 void 180 res_send_setrhook(res_send_rhook hook) { 181 _res.rhook = hook; 182 } 183 #endif 184 185 int 186 res_isourserver(const struct sockaddr_in *inp) { 187 return (res_ourserver_p(&_res, inp)); 188 } 189 190 int 191 res_send(const u_char *buf, int buflen, u_char *ans, int anssiz) { 192 res_state statp = &_res; 193 if ((statp->options & RES_INIT) == 0U && res_init() == -1) { 194 /* errno should have been set by res_init() in this case. */ 195 return (-1); 196 } 197 198 return (res_nsend(statp, buf, buflen, ans, anssiz)); 199 } 200 201 #ifndef _LIBC 202 int 203 res_sendsigned(const u_char *buf, int buflen, ns_tsig_key *key, 204 u_char *ans, int anssiz) 205 { 206 res_state statp = &_res; 207 if ((statp->options & RES_INIT) == 0U && res_init() == -1) { 208 /* errno should have been set by res_init() in this case. */ 209 return (-1); 210 } 211 212 return (res_nsendsigned(statp, buf, buflen, key, ans, anssiz)); 213 } 214 #endif 215 216 void 217 res_close(void) { 218 res_nclose(&_res); 219 } 220 221 int 222 res_update(ns_updrec *rrecp_in) { 223 res_state statp = &_res; 224 if ((statp->options & RES_INIT) == 0U && res_init() == -1) { 225 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 226 return (-1); 227 } 228 229 return (res_nupdate(statp, rrecp_in, NULL)); 230 } 231 232 int 233 res_search(const char *name, /*!< domain name */ 234 int class, int type, /*!< class and type of query */ 235 u_char *answer, /*!< buffer to put answer */ 236 int anslen) /*!< size of answer */ 237 { 238 res_state statp = &_res; 239 if ((statp->options & RES_INIT) == 0U && res_init() == -1) { 240 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 241 return (-1); 242 } 243 244 return (res_nsearch(statp, name, class, type, answer, anslen)); 245 } 246 247 int 248 res_querydomain(const char *name, 249 const char *domain, 250 int class, int type, /*!< class and type of query */ 251 u_char *answer, /*!< buffer to put answer */ 252 int anslen) /*!< size of answer */ 253 { 254 res_state statp = &_res; 255 if ((statp->options & RES_INIT) == 0U && res_init() == -1) { 256 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 257 return (-1); 258 } 259 260 return (res_nquerydomain(statp, name, domain, 261 class, type, 262 answer, anslen)); 263 } 264 265 u_int 266 res_randomid(void) { 267 res_state statp = &_res; 268 if ((statp->options & RES_INIT) == 0U && res_init() == -1) { 269 RES_SET_H_ERRNO(statp, NETDB_INTERNAL); 270 return (-1); 271 } 272 273 return (res_nrandomid(statp)); 274 } 275 276 int 277 res_opt(int n0, u_char *buf, int buflen, int anslen) 278 { 279 return (res_nopt(&_res, n0, buf, buflen, anslen)); 280 } 281 282 const char * 283 hostalias(const char *name) { 284 static char abuf[MAXDNAME]; 285 286 return (res_hostalias(&_res, name, abuf, sizeof abuf)); 287 } 288 289 #ifdef ultrix 290 int 291 local_hostname_length(const char *hostname) { 292 int len_host, len_domain; 293 res_state statp; 294 295 statp = &_res; 296 if (!*statp->defdname) 297 res_init(); 298 len_host = strlen(hostname); 299 len_domain = strlen(statp->defdname); 300 if (len_host > len_domain && 301 !strcasecmp(hostname + len_host - len_domain, statp->defdname) && 302 hostname[len_host - len_domain - 1] == '.') 303 return (len_host - len_domain - 1); 304 return (0); 305 } 306 #endif /*ultrix*/ 307 308 /* 309 * Weak aliases for applications that use certain private entry points, 310 * and fail to include <resolv.h>. 311 */ 312 #undef res_init 313 __weak_reference(__res_init, res_init); 314 #undef p_query 315 __weak_reference(__p_query, p_query); 316 #undef res_mkquery 317 __weak_reference(__res_mkquery, res_mkquery); 318 #undef res_query 319 __weak_reference(__res_query, res_query); 320 #undef res_send 321 __weak_reference(__res_send, res_send); 322 #undef res_close 323 __weak_reference(__res_close, _res_close); 324 #undef res_search 325 __weak_reference(__res_search, res_search); 326 #undef res_querydomain 327 __weak_reference(__res_querydomain, res_querydomain); 328 329 #endif 330 331 /*! \file */ 332