1 /* 2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (c) 1996,1999 by Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and 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 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 /* Imports */ 19 20 #include "port_before.h" 21 22 #include <sys/types.h> 23 24 #include <netinet/in.h> 25 #include <arpa/nameser.h> 26 27 #include <errno.h> 28 #include <stdlib.h> 29 #include <netdb.h> 30 #include <resolv.h> 31 #include <stdio.h> 32 #include <string.h> 33 34 #include <isc/memcluster.h> 35 #include <irs.h> 36 37 #include "port_after.h" 38 39 #include "irs_p.h" 40 #include "gen_p.h" 41 42 /* Definitions */ 43 44 struct pvt { 45 struct irs_rule * rules; 46 struct irs_rule * rule; 47 struct irs_ho * ho; 48 struct __res_state * res; 49 void (*free_res)(void *); 50 }; 51 52 /* Forwards */ 53 54 static void ho_close(struct irs_ho *this); 55 static struct hostent * ho_byname(struct irs_ho *this, const char *name); 56 static struct hostent * ho_byname2(struct irs_ho *this, const char *name, 57 int af); 58 static struct hostent * ho_byaddr(struct irs_ho *this, const void *addr, 59 int len, int af); 60 static struct hostent * ho_next(struct irs_ho *this); 61 static void ho_rewind(struct irs_ho *this); 62 static void ho_minimize(struct irs_ho *this); 63 static struct __res_state * ho_res_get(struct irs_ho *this); 64 static void ho_res_set(struct irs_ho *this, 65 struct __res_state *res, 66 void (*free_res)(void *)); 67 static struct addrinfo * ho_addrinfo(struct irs_ho *this, const char *name, 68 const struct addrinfo *pai); 69 70 static int init(struct irs_ho *this); 71 72 /* Exports */ 73 74 struct irs_ho * 75 irs_gen_ho(struct irs_acc *this) { 76 struct gen_p *accpvt = (struct gen_p *)this->private; 77 struct irs_ho *ho; 78 struct pvt *pvt; 79 80 if (!(pvt = memget(sizeof *pvt))) { 81 errno = ENOMEM; 82 return (NULL); 83 } 84 memset(pvt, 0, sizeof *pvt); 85 if (!(ho = memget(sizeof *ho))) { 86 memput(pvt, sizeof *pvt); 87 errno = ENOMEM; 88 return (NULL); 89 } 90 memset(ho, 0x5e, sizeof *ho); 91 pvt->rules = accpvt->map_rules[irs_ho]; 92 pvt->rule = pvt->rules; 93 ho->private = pvt; 94 ho->close = ho_close; 95 ho->byname = ho_byname; 96 ho->byname2 = ho_byname2; 97 ho->byaddr = ho_byaddr; 98 ho->next = ho_next; 99 ho->rewind = ho_rewind; 100 ho->minimize = ho_minimize; 101 ho->res_get = ho_res_get; 102 ho->res_set = ho_res_set; 103 ho->addrinfo = ho_addrinfo; 104 return (ho); 105 } 106 107 /* Methods. */ 108 109 static void 110 ho_close(struct irs_ho *this) { 111 struct pvt *pvt = (struct pvt *)this->private; 112 113 ho_minimize(this); 114 if (pvt->res && pvt->free_res) 115 (*pvt->free_res)(pvt->res); 116 memput(pvt, sizeof *pvt); 117 memput(this, sizeof *this); 118 } 119 120 static struct hostent * 121 ho_byname(struct irs_ho *this, const char *name) { 122 struct pvt *pvt = (struct pvt *)this->private; 123 struct irs_rule *rule; 124 struct hostent *rval; 125 struct irs_ho *ho; 126 int therrno = NETDB_INTERNAL; 127 int softerror = 0; 128 129 if (init(this) == -1) 130 return (NULL); 131 132 for (rule = pvt->rules; rule; rule = rule->next) { 133 ho = rule->inst->ho; 134 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); 135 errno = 0; 136 rval = (*ho->byname)(ho, name); 137 if (rval != NULL) 138 return (rval); 139 if (softerror == 0 && 140 pvt->res->res_h_errno != HOST_NOT_FOUND && 141 pvt->res->res_h_errno != NETDB_INTERNAL) { 142 softerror = 1; 143 therrno = pvt->res->res_h_errno; 144 } 145 if (rule->flags & IRS_CONTINUE) 146 continue; 147 /* 148 * The value TRY_AGAIN can mean that the service 149 * is not available, or just that this particular name 150 * cannot be resolved now. We use the errno ECONNREFUSED 151 * to distinguish. If a lookup sets that errno when 152 * H_ERRNO is TRY_AGAIN, we continue to try other lookup 153 * functions, otherwise we return the TRY_AGAIN error. 154 */ 155 if (pvt->res->res_h_errno != TRY_AGAIN || errno != ECONNREFUSED) 156 break; 157 } 158 if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND) 159 RES_SET_H_ERRNO(pvt->res, therrno); 160 return (NULL); 161 } 162 163 static struct hostent * 164 ho_byname2(struct irs_ho *this, const char *name, int af) { 165 struct pvt *pvt = (struct pvt *)this->private; 166 struct irs_rule *rule; 167 struct hostent *rval; 168 struct irs_ho *ho; 169 int therrno = NETDB_INTERNAL; 170 int softerror = 0; 171 172 if (init(this) == -1) 173 return (NULL); 174 175 for (rule = pvt->rules; rule; rule = rule->next) { 176 ho = rule->inst->ho; 177 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); 178 errno = 0; 179 rval = (*ho->byname2)(ho, name, af); 180 if (rval != NULL) 181 return (rval); 182 if (softerror == 0 && 183 pvt->res->res_h_errno != HOST_NOT_FOUND && 184 pvt->res->res_h_errno != NETDB_INTERNAL) { 185 softerror = 1; 186 therrno = pvt->res->res_h_errno; 187 } 188 if (rule->flags & IRS_CONTINUE) 189 continue; 190 /* 191 * See the comments in ho_byname() explaining 192 * the interpretation of TRY_AGAIN and ECONNREFUSED. 193 */ 194 if (pvt->res->res_h_errno != TRY_AGAIN || errno != ECONNREFUSED) 195 break; 196 } 197 if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND) 198 RES_SET_H_ERRNO(pvt->res, therrno); 199 return (NULL); 200 } 201 202 static struct hostent * 203 ho_byaddr(struct irs_ho *this, const void *addr, int len, int af) { 204 struct pvt *pvt = (struct pvt *)this->private; 205 struct irs_rule *rule; 206 struct hostent *rval; 207 struct irs_ho *ho; 208 int therrno = NETDB_INTERNAL; 209 int softerror = 0; 210 211 212 if (init(this) == -1) 213 return (NULL); 214 215 for (rule = pvt->rules; rule; rule = rule->next) { 216 ho = rule->inst->ho; 217 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); 218 errno = 0; 219 rval = (*ho->byaddr)(ho, addr, len, af); 220 if (rval != NULL) 221 return (rval); 222 if (softerror == 0 && 223 pvt->res->res_h_errno != HOST_NOT_FOUND && 224 pvt->res->res_h_errno != NETDB_INTERNAL) { 225 softerror = 1; 226 therrno = pvt->res->res_h_errno; 227 } 228 229 if (rule->flags & IRS_CONTINUE) 230 continue; 231 /* 232 * See the comments in ho_byname() explaining 233 * the interpretation of TRY_AGAIN and ECONNREFUSED. 234 */ 235 if (pvt->res->res_h_errno != TRY_AGAIN || errno != ECONNREFUSED) 236 break; 237 } 238 if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND) 239 RES_SET_H_ERRNO(pvt->res, therrno); 240 return (NULL); 241 } 242 243 static struct hostent * 244 ho_next(struct irs_ho *this) { 245 struct pvt *pvt = (struct pvt *)this->private; 246 struct hostent *rval; 247 struct irs_ho *ho; 248 249 while (pvt->rule) { 250 ho = pvt->rule->inst->ho; 251 rval = (*ho->next)(ho); 252 if (rval) 253 return (rval); 254 if (!(pvt->rule->flags & IRS_CONTINUE)) 255 break; 256 pvt->rule = pvt->rule->next; 257 if (pvt->rule) { 258 ho = pvt->rule->inst->ho; 259 (*ho->rewind)(ho); 260 } 261 } 262 return (NULL); 263 } 264 265 static void 266 ho_rewind(struct irs_ho *this) { 267 struct pvt *pvt = (struct pvt *)this->private; 268 struct irs_ho *ho; 269 270 pvt->rule = pvt->rules; 271 if (pvt->rule) { 272 ho = pvt->rule->inst->ho; 273 (*ho->rewind)(ho); 274 } 275 } 276 277 static void 278 ho_minimize(struct irs_ho *this) { 279 struct pvt *pvt = (struct pvt *)this->private; 280 struct irs_rule *rule; 281 282 if (pvt->res) 283 res_nclose(pvt->res); 284 for (rule = pvt->rules; rule != NULL; rule = rule->next) { 285 struct irs_ho *ho = rule->inst->ho; 286 287 (*ho->minimize)(ho); 288 } 289 } 290 291 static struct __res_state * 292 ho_res_get(struct irs_ho *this) { 293 struct pvt *pvt = (struct pvt *)this->private; 294 295 if (!pvt->res) { 296 struct __res_state *res; 297 res = (struct __res_state *)malloc(sizeof *res); 298 if (!res) { 299 errno = ENOMEM; 300 return (NULL); 301 } 302 memset(res, 0, sizeof *res); 303 ho_res_set(this, res, free); 304 } 305 306 return (pvt->res); 307 } 308 309 static void 310 ho_res_set(struct irs_ho *this, struct __res_state *res, 311 void (*free_res)(void *)) { 312 struct pvt *pvt = (struct pvt *)this->private; 313 struct irs_rule *rule; 314 315 if (pvt->res && pvt->free_res) { 316 res_nclose(pvt->res); 317 (*pvt->free_res)(pvt->res); 318 } 319 320 pvt->res = res; 321 pvt->free_res = free_res; 322 323 for (rule = pvt->rules; rule != NULL; rule = rule->next) { 324 struct irs_ho *ho = rule->inst->ho; 325 326 (*ho->res_set)(ho, pvt->res, NULL); 327 } 328 } 329 330 static struct addrinfo * 331 ho_addrinfo(struct irs_ho *this, const char *name, const struct addrinfo *pai) 332 { 333 struct pvt *pvt = (struct pvt *)this->private; 334 struct irs_rule *rule; 335 struct addrinfo *rval = NULL; 336 struct irs_ho *ho; 337 int therrno = NETDB_INTERNAL; 338 int softerror = 0; 339 340 if (init(this) == -1) 341 return (NULL); 342 343 for (rule = pvt->rules; rule; rule = rule->next) { 344 ho = rule->inst->ho; 345 RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); 346 errno = 0; 347 if (ho->addrinfo == NULL) /*%< for safety */ 348 continue; 349 rval = (*ho->addrinfo)(ho, name, pai); 350 if (rval != NULL) 351 return (rval); 352 if (softerror == 0 && 353 pvt->res->res_h_errno != HOST_NOT_FOUND && 354 pvt->res->res_h_errno != NETDB_INTERNAL) { 355 softerror = 1; 356 therrno = pvt->res->res_h_errno; 357 } 358 if (rule->flags & IRS_CONTINUE) 359 continue; 360 /* 361 * See the comments in ho_byname() explaining 362 * the interpretation of TRY_AGAIN and ECONNREFUSED. 363 */ 364 if (pvt->res->res_h_errno != TRY_AGAIN || 365 errno != ECONNREFUSED) 366 break; 367 } 368 if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND) 369 RES_SET_H_ERRNO(pvt->res, therrno); 370 return (NULL); 371 } 372 373 static int 374 init(struct irs_ho *this) { 375 struct pvt *pvt = (struct pvt *)this->private; 376 377 if (!pvt->res && !ho_res_get(this)) 378 return (-1); 379 380 if (((pvt->res->options & RES_INIT) == 0U) && 381 (res_ninit(pvt->res) == -1)) 382 return (-1); 383 384 return (0); 385 } 386 387 /*! \file */ 388