| 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 | #if defined(LIBC_SCCS) && !defined(lint) |
| 19 | static const char rcsid[] = "$Id: gen_ho.c,v 1.5 2006/03/09 23:57:56 marka Exp $"; |
| 20 | #endif /* LIBC_SCCS and not lint */ |
| 21 | |
| 22 | /* Imports */ |
| 23 | |
| 24 | #include "port_before.h" |
| 25 | |
| 26 | #include <sys/types.h> |
| 27 | |
| 28 | #include <netinet/in.h> |
| 29 | #include <arpa/nameser.h> |
| 30 | |
| 31 | #include <errno.h> |
| 32 | #include <stdlib.h> |
| 33 | #include <netdb.h> |
| 34 | #include <resolv.h> |
| 35 | #include <stdio.h> |
| 36 | #include <string.h> |
| 37 | |
| 38 | #include <isc/memcluster.h> |
| 39 | #include <irs.h> |
| 40 | |
| 41 | #include "port_after.h" |
| 42 | |
| 43 | #include "irs_p.h" |
| 44 | #include "gen_p.h" |
| 45 | |
| 46 | /* Definitions */ |
| 47 | |
| 48 | struct pvt { |
| 49 | struct irs_rule * rules; |
| 50 | struct irs_rule * rule; |
| 51 | struct irs_ho * ho; |
| 52 | struct __res_state * res; |
| 53 | void (*free_res)(void *); |
| 54 | }; |
| 55 | |
| 56 | /* Forwards */ |
| 57 | |
| 58 | static void ho_close(struct irs_ho *this); |
| 59 | static struct hostent * ho_byname(struct irs_ho *this, const char *name); |
| 60 | static struct hostent * ho_byname2(struct irs_ho *this, const char *name, |
| 61 | int af); |
| 62 | static struct hostent * ho_byaddr(struct irs_ho *this, const void *addr, |
| 63 | int len, int af); |
| 64 | static struct hostent * ho_next(struct irs_ho *this); |
| 65 | static void ho_rewind(struct irs_ho *this); |
| 66 | static void ho_minimize(struct irs_ho *this); |
| 67 | static struct __res_state * ho_res_get(struct irs_ho *this); |
| 68 | static void ho_res_set(struct irs_ho *this, |
| 69 | struct __res_state *res, |
| 70 | void (*free_res)(void *)); |
| 71 | static struct addrinfo * ho_addrinfo(struct irs_ho *this, const char *name, |
| 72 | const struct addrinfo *pai); |
| 73 | |
| 74 | static int init(struct irs_ho *this); |
| 75 | |
| 76 | /* Exports */ |
| 77 | |
| 78 | struct irs_ho * |
| 79 | irs_gen_ho(struct irs_acc *this) { |
| 80 | struct gen_p *accpvt = (struct gen_p *)this->private; |
| 81 | struct irs_ho *ho; |
| 82 | struct pvt *pvt; |
| 83 | |
| 84 | if (!(pvt = memget(sizeof *pvt))) { |
| 85 | errno = ENOMEM; |
| 86 | return (NULL); |
| 87 | } |
| 88 | memset(pvt, 0, sizeof *pvt); |
| 89 | if (!(ho = memget(sizeof *ho))) { |
| 90 | memput(pvt, sizeof *pvt); |
| 91 | errno = ENOMEM; |
| 92 | return (NULL); |
| 93 | } |
| 94 | memset(ho, 0x5e, sizeof *ho); |
| 95 | pvt->rules = accpvt->map_rules[irs_ho]; |
| 96 | pvt->rule = pvt->rules; |
| 97 | ho->private = pvt; |
| 98 | ho->close = ho_close; |
| 99 | ho->byname = ho_byname; |
| 100 | ho->byname2 = ho_byname2; |
| 101 | ho->byaddr = ho_byaddr; |
| 102 | ho->next = ho_next; |
| 103 | ho->rewind = ho_rewind; |
| 104 | ho->minimize = ho_minimize; |
| 105 | ho->res_get = ho_res_get; |
| 106 | ho->res_set = ho_res_set; |
| 107 | ho->addrinfo = ho_addrinfo; |
| 108 | return (ho); |
| 109 | } |
| 110 | |
| 111 | /* Methods. */ |
| 112 | |
| 113 | static void |
| 114 | ho_close(struct irs_ho *this) { |
| 115 | struct pvt *pvt = (struct pvt *)this->private; |
| 116 | |
| 117 | ho_minimize(this); |
| 118 | if (pvt->res && pvt->free_res) |
| 119 | (*pvt->free_res)(pvt->res); |
| 120 | memput(pvt, sizeof *pvt); |
| 121 | memput(this, sizeof *this); |
| 122 | } |
| 123 | |
| 124 | static struct hostent * |
| 125 | ho_byname(struct irs_ho *this, const char *name) { |
| 126 | struct pvt *pvt = (struct pvt *)this->private; |
| 127 | struct irs_rule *rule; |
| 128 | struct hostent *rval; |
| 129 | struct irs_ho *ho; |
| 130 | int therrno = NETDB_INTERNAL; |
| 131 | int softerror = 0; |
| 132 | |
| 133 | if (init(this) == -1) |
| 134 | return (NULL); |
| 135 | |
| 136 | for (rule = pvt->rules; rule; rule = rule->next) { |
| 137 | ho = rule->inst->ho; |
| 138 | RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); |
| 139 | errno = 0; |
| 140 | rval = (*ho->byname)(ho, name); |
| 141 | if (rval != NULL) |
| 142 | return (rval); |
| 143 | if (softerror == 0 && |
| 144 | pvt->res->res_h_errno != HOST_NOT_FOUND && |
| 145 | pvt->res->res_h_errno != NETDB_INTERNAL) { |
| 146 | softerror = 1; |
| 147 | therrno = pvt->res->res_h_errno; |
| 148 | } |
| 149 | if (rule->flags & IRS_CONTINUE) |
| 150 | continue; |
| 151 | /* |
| 152 | * The value TRY_AGAIN can mean that the service |
| 153 | * is not available, or just that this particular name |
| 154 | * cannot be resolved now. We use the errno ECONNREFUSED |
| 155 | * to distinguish. If a lookup sets that errno when |
| 156 | * H_ERRNO is TRY_AGAIN, we continue to try other lookup |
| 157 | * functions, otherwise we return the TRY_AGAIN error. |
| 158 | */ |
| 159 | if (pvt->res->res_h_errno != TRY_AGAIN || errno != ECONNREFUSED) |
| 160 | break; |
| 161 | } |
| 162 | if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND) |
| 163 | RES_SET_H_ERRNO(pvt->res, therrno); |
| 164 | return (NULL); |
| 165 | } |
| 166 | |
| 167 | static struct hostent * |
| 168 | ho_byname2(struct irs_ho *this, const char *name, int af) { |
| 169 | struct pvt *pvt = (struct pvt *)this->private; |
| 170 | struct irs_rule *rule; |
| 171 | struct hostent *rval; |
| 172 | struct irs_ho *ho; |
| 173 | int therrno = NETDB_INTERNAL; |
| 174 | int softerror = 0; |
| 175 | |
| 176 | if (init(this) == -1) |
| 177 | return (NULL); |
| 178 | |
| 179 | for (rule = pvt->rules; rule; rule = rule->next) { |
| 180 | ho = rule->inst->ho; |
| 181 | RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); |
| 182 | errno = 0; |
| 183 | rval = (*ho->byname2)(ho, name, af); |
| 184 | if (rval != NULL) |
| 185 | return (rval); |
| 186 | if (softerror == 0 && |
| 187 | pvt->res->res_h_errno != HOST_NOT_FOUND && |
| 188 | pvt->res->res_h_errno != NETDB_INTERNAL) { |
| 189 | softerror = 1; |
| 190 | therrno = pvt->res->res_h_errno; |
| 191 | } |
| 192 | if (rule->flags & IRS_CONTINUE) |
| 193 | continue; |
| 194 | /* |
| 195 | * See the comments in ho_byname() explaining |
| 196 | * the interpretation of TRY_AGAIN and ECONNREFUSED. |
| 197 | */ |
| 198 | if (pvt->res->res_h_errno != TRY_AGAIN || errno != ECONNREFUSED) |
| 199 | break; |
| 200 | } |
| 201 | if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND) |
| 202 | RES_SET_H_ERRNO(pvt->res, therrno); |
| 203 | return (NULL); |
| 204 | } |
| 205 | |
| 206 | static struct hostent * |
| 207 | ho_byaddr(struct irs_ho *this, const void *addr, int len, int af) { |
| 208 | struct pvt *pvt = (struct pvt *)this->private; |
| 209 | struct irs_rule *rule; |
| 210 | struct hostent *rval; |
| 211 | struct irs_ho *ho; |
| 212 | int therrno = NETDB_INTERNAL; |
| 213 | int softerror = 0; |
| 214 | |
| 215 | |
| 216 | if (init(this) == -1) |
| 217 | return (NULL); |
| 218 | |
| 219 | for (rule = pvt->rules; rule; rule = rule->next) { |
| 220 | ho = rule->inst->ho; |
| 221 | RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); |
| 222 | errno = 0; |
| 223 | rval = (*ho->byaddr)(ho, addr, len, af); |
| 224 | if (rval != NULL) |
| 225 | return (rval); |
| 226 | if (softerror == 0 && |
| 227 | pvt->res->res_h_errno != HOST_NOT_FOUND && |
| 228 | pvt->res->res_h_errno != NETDB_INTERNAL) { |
| 229 | softerror = 1; |
| 230 | therrno = pvt->res->res_h_errno; |
| 231 | } |
| 232 | |
| 233 | if (rule->flags & IRS_CONTINUE) |
| 234 | continue; |
| 235 | /* |
| 236 | * See the comments in ho_byname() explaining |
| 237 | * the interpretation of TRY_AGAIN and ECONNREFUSED. |
| 238 | */ |
| 239 | if (pvt->res->res_h_errno != TRY_AGAIN || errno != ECONNREFUSED) |
| 240 | break; |
| 241 | } |
| 242 | if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND) |
| 243 | RES_SET_H_ERRNO(pvt->res, therrno); |
| 244 | return (NULL); |
| 245 | } |
| 246 | |
| 247 | static struct hostent * |
| 248 | ho_next(struct irs_ho *this) { |
| 249 | struct pvt *pvt = (struct pvt *)this->private; |
| 250 | struct hostent *rval; |
| 251 | struct irs_ho *ho; |
| 252 | |
| 253 | while (pvt->rule) { |
| 254 | ho = pvt->rule->inst->ho; |
| 255 | rval = (*ho->next)(ho); |
| 256 | if (rval) |
| 257 | return (rval); |
| 258 | if (!(pvt->rule->flags & IRS_CONTINUE)) |
| 259 | break; |
| 260 | pvt->rule = pvt->rule->next; |
| 261 | if (pvt->rule) { |
| 262 | ho = pvt->rule->inst->ho; |
| 263 | (*ho->rewind)(ho); |
| 264 | } |
| 265 | } |
| 266 | return (NULL); |
| 267 | } |
| 268 | |
| 269 | static void |
| 270 | ho_rewind(struct irs_ho *this) { |
| 271 | struct pvt *pvt = (struct pvt *)this->private; |
| 272 | struct irs_ho *ho; |
| 273 | |
| 274 | pvt->rule = pvt->rules; |
| 275 | if (pvt->rule) { |
| 276 | ho = pvt->rule->inst->ho; |
| 277 | (*ho->rewind)(ho); |
| 278 | } |
| 279 | } |
| 280 | |
| 281 | static void |
| 282 | ho_minimize(struct irs_ho *this) { |
| 283 | struct pvt *pvt = (struct pvt *)this->private; |
| 284 | struct irs_rule *rule; |
| 285 | |
| 286 | if (pvt->res) |
| 287 | res_nclose(pvt->res); |
| 288 | for (rule = pvt->rules; rule != NULL; rule = rule->next) { |
| 289 | struct irs_ho *ho = rule->inst->ho; |
| 290 | |
| 291 | (*ho->minimize)(ho); |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | static struct __res_state * |
| 296 | ho_res_get(struct irs_ho *this) { |
| 297 | struct pvt *pvt = (struct pvt *)this->private; |
| 298 | |
| 299 | if (!pvt->res) { |
| 300 | struct __res_state *res; |
| 301 | res = (struct __res_state *)malloc(sizeof *res); |
| 302 | if (!res) { |
| 303 | errno = ENOMEM; |
| 304 | return (NULL); |
| 305 | } |
| 306 | memset(res, 0, sizeof *res); |
| 307 | ho_res_set(this, res, free); |
| 308 | } |
| 309 | |
| 310 | return (pvt->res); |
| 311 | } |
| 312 | |
| 313 | static void |
| 314 | ho_res_set(struct irs_ho *this, struct __res_state *res, |
| 315 | void (*free_res)(void *)) { |
| 316 | struct pvt *pvt = (struct pvt *)this->private; |
| 317 | struct irs_rule *rule; |
| 318 | |
| 319 | if (pvt->res && pvt->free_res) { |
| 320 | res_nclose(pvt->res); |
| 321 | (*pvt->free_res)(pvt->res); |
| 322 | } |
| 323 | |
| 324 | pvt->res = res; |
| 325 | pvt->free_res = free_res; |
| 326 | |
| 327 | for (rule = pvt->rules; rule != NULL; rule = rule->next) { |
| 328 | struct irs_ho *ho = rule->inst->ho; |
| 329 | |
| 330 | (*ho->res_set)(ho, pvt->res, NULL); |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | static struct addrinfo * |
| 335 | ho_addrinfo(struct irs_ho *this, const char *name, const struct addrinfo *pai) |
| 336 | { |
| 337 | struct pvt *pvt = (struct pvt *)this->private; |
| 338 | struct irs_rule *rule; |
| 339 | struct addrinfo *rval = NULL; |
| 340 | struct irs_ho *ho; |
| 341 | int therrno = NETDB_INTERNAL; |
| 342 | int softerror = 0; |
| 343 | |
| 344 | if (init(this) == -1) |
| 345 | return (NULL); |
| 346 | |
| 347 | for (rule = pvt->rules; rule; rule = rule->next) { |
| 348 | ho = rule->inst->ho; |
| 349 | RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL); |
| 350 | errno = 0; |
| 351 | if (ho->addrinfo == NULL) /*%< for safety */ |
| 352 | continue; |
| 353 | rval = (*ho->addrinfo)(ho, name, pai); |
| 354 | if (rval != NULL) |
| 355 | return (rval); |
| 356 | if (softerror == 0 && |
| 357 | pvt->res->res_h_errno != HOST_NOT_FOUND && |
| 358 | pvt->res->res_h_errno != NETDB_INTERNAL) { |
| 359 | softerror = 1; |
| 360 | therrno = pvt->res->res_h_errno; |
| 361 | } |
| 362 | if (rule->flags & IRS_CONTINUE) |
| 363 | continue; |
| 364 | /* |
| 365 | * See the comments in ho_byname() explaining |
| 366 | * the interpretation of TRY_AGAIN and ECONNREFUSED. |
| 367 | */ |
| 368 | if (pvt->res->res_h_errno != TRY_AGAIN || |
| 369 | errno != ECONNREFUSED) |
| 370 | break; |
| 371 | } |
| 372 | if (softerror != 0 && pvt->res->res_h_errno == HOST_NOT_FOUND) |
| 373 | RES_SET_H_ERRNO(pvt->res, therrno); |
| 374 | return (NULL); |
| 375 | } |
| 376 | |
| 377 | static int |
| 378 | init(struct irs_ho *this) { |
| 379 | struct pvt *pvt = (struct pvt *)this->private; |
| 380 | |
| 381 | if (!pvt->res && !ho_res_get(this)) |
| 382 | return (-1); |
| 383 | |
| 384 | if (((pvt->res->options & RES_INIT) == 0U) && |
| 385 | (res_ninit(pvt->res) == -1)) |
| 386 | return (-1); |
| 387 | |
| 388 | return (0); |
| 389 | } |
| 390 | |
| 391 | /*! \file */ |