contrib/bind9/lib/isccfg/aclconf.c

   1 /*
   2  * Copyright (C) 2004-2012, 2014, 2016  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 1999-2002  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and/or 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 WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id$ */
  19
  20 #include <config.h>
  21
  22 #include <isc/mem.h>
  23 #include <isc/string.h>         /* Required for HP/UX (and others?) */
  24 #include <isc/util.h>
  25
  26 #include <isccfg/namedconf.h>
  27 #include <isccfg/aclconf.h>
  28
  29 #include <dns/acl.h>
  30 #include <dns/iptable.h>
  31 #include <dns/fixedname.h>
  32 #include <dns/log.h>
  33
  34 #define LOOP_MAGIC ISC_MAGIC('L','O','O','P')
  35
  36 isc_result_t
  37 cfg_aclconfctx_create(isc_mem_t *mctx, cfg_aclconfctx_t **ret) {
  38         isc_result_t result;
  39         cfg_aclconfctx_t *actx;
  40
  41         REQUIRE(mctx != NULL);
  42         REQUIRE(ret != NULL && *ret == NULL);
  43
  44         actx = isc_mem_get(mctx, sizeof(*actx));
  45         if (actx == NULL)
  46                 return (ISC_R_NOMEMORY);
  47
  48         result = isc_refcount_init(&actx->references, 1);
  49         if (result != ISC_R_SUCCESS)
  50                 goto cleanup;
  51
  52         actx->mctx = NULL;
  53         isc_mem_attach(mctx, &actx->mctx);
  54         ISC_LIST_INIT(actx->named_acl_cache);
  55
  56         *ret = actx;
  57         return (ISC_R_SUCCESS);
  58
  59  cleanup:
  60         isc_mem_put(mctx, actx, sizeof(*actx));
  61         return (result);
  62 }
  63
  64 void
  65 cfg_aclconfctx_attach(cfg_aclconfctx_t *src, cfg_aclconfctx_t **dest) {
  66         REQUIRE(src != NULL);
  67         REQUIRE(dest != NULL && *dest == NULL);
  68
  69         isc_refcount_increment(&src->references, NULL);
  70         *dest = src;
  71 }
  72
  73 void
  74 cfg_aclconfctx_detach(cfg_aclconfctx_t **actxp) {
  75         cfg_aclconfctx_t *actx;
  76         dns_acl_t *dacl, *next;
  77         unsigned int refs;
  78
  79         REQUIRE(actxp != NULL && *actxp != NULL);
  80
  81         actx = *actxp;
  82
  83         isc_refcount_decrement(&actx->references, &refs);
  84         if (refs == 0) {
  85                 for (dacl = ISC_LIST_HEAD(actx->named_acl_cache);
  86                      dacl != NULL;
  87                      dacl = next)
  88                 {
  89                         next = ISC_LIST_NEXT(dacl, nextincache);
  90                         ISC_LIST_UNLINK(actx->named_acl_cache, dacl,
  91                                         nextincache);
  92                         dns_acl_detach(&dacl);
  93                 }
  94                 isc_mem_putanddetach(&actx->mctx, actx, sizeof(*actx));
  95         }
  96
  97         *actxp = NULL;
  98 }
  99
 100 /*
 101  * Find the definition of the named acl whose name is "name".
 102  */
 103 static isc_result_t
 104 get_acl_def(const cfg_obj_t *cctx, const char *name, const cfg_obj_t **ret) {
 105         isc_result_t result;
 106         const cfg_obj_t *acls = NULL;
 107         const cfg_listelt_t *elt;
 108
 109         result = cfg_map_get(cctx, "acl", &acls);
 110         if (result != ISC_R_SUCCESS)
 111                 return (result);
 112         for (elt = cfg_list_first(acls);
 113              elt != NULL;
 114              elt = cfg_list_next(elt)) {
 115                 const cfg_obj_t *acl = cfg_listelt_value(elt);
 116                 const char *aclname = cfg_obj_asstring(cfg_tuple_get(acl, "name"));
 117                 if (strcasecmp(aclname, name) == 0) {
 118                         if (ret != NULL) {
 119                                 *ret = cfg_tuple_get(acl, "value");
 120                         }
 121                         return (ISC_R_SUCCESS);
 122                 }
 123         }
 124         return (ISC_R_NOTFOUND);
 125 }
 126
 127 static isc_result_t
 128 convert_named_acl(const cfg_obj_t *nameobj, const cfg_obj_t *cctx,
 129                   isc_log_t *lctx, cfg_aclconfctx_t *ctx,
 130                   isc_mem_t *mctx, unsigned int nest_level,
 131                   dns_acl_t **target)
 132 {
 133         isc_result_t result;
 134         const cfg_obj_t *cacl = NULL;
 135         dns_acl_t *dacl;
 136         dns_acl_t loop;
 137         const char *aclname = cfg_obj_asstring(nameobj);
 138
 139         /* Look for an already-converted version. */
 140         for (dacl = ISC_LIST_HEAD(ctx->named_acl_cache);
 141              dacl != NULL;
 142              dacl = ISC_LIST_NEXT(dacl, nextincache))
 143         {
 144                 if (strcasecmp(aclname, dacl->name) == 0) {
 145                         if (ISC_MAGIC_VALID(dacl, LOOP_MAGIC)) {
 146                                 cfg_obj_log(nameobj, lctx, ISC_LOG_ERROR,
 147                                             "acl loop detected: %s", aclname);
 148                                 return (ISC_R_FAILURE);
 149                         }
 150                         dns_acl_attach(dacl, target);
 151                         return (ISC_R_SUCCESS);
 152                 }
 153         }
 154         /* Not yet converted.  Convert now. */
 155         result = get_acl_def(cctx, aclname, &cacl);
 156         if (result != ISC_R_SUCCESS) {
 157                 cfg_obj_log(nameobj, lctx, ISC_LOG_WARNING,
 158                             "undefined ACL '%s'", aclname);
 159                 return (result);
 160         }
 161         /*
 162          * Add a loop detection element.
 163          */
 164         memset(&loop, 0, sizeof(loop));
 165         ISC_LINK_INIT(&loop, nextincache);
 166         DE_CONST(aclname, loop.name);
 167         loop.magic = LOOP_MAGIC;
 168         ISC_LIST_APPEND(ctx->named_acl_cache, &loop, nextincache);
 169         result = cfg_acl_fromconfig(cacl, cctx, lctx, ctx, mctx,
 170                                     nest_level, &dacl);
 171         ISC_LIST_UNLINK(ctx->named_acl_cache, &loop, nextincache);
 172         loop.magic = 0;
 173         loop.name = NULL;
 174         if (result != ISC_R_SUCCESS)
 175                 return (result);
 176         dacl->name = isc_mem_strdup(dacl->mctx, aclname);
 177         if (dacl->name == NULL)
 178                 return (ISC_R_NOMEMORY);
 179         ISC_LIST_APPEND(ctx->named_acl_cache, dacl, nextincache);
 180         dns_acl_attach(dacl, target);
 181         return (ISC_R_SUCCESS);
 182 }
 183
 184 static isc_result_t
 185 convert_keyname(const cfg_obj_t *keyobj, isc_log_t *lctx, isc_mem_t *mctx,
 186                 dns_name_t *dnsname)
 187 {
 188         isc_result_t result;
 189         isc_buffer_t buf;
 190         dns_fixedname_t fixname;
 191         unsigned int keylen;
 192         const char *txtname = cfg_obj_asstring(keyobj);
 193
 194         keylen = strlen(txtname);
 195         isc_buffer_constinit(&buf, txtname, keylen);
 196         isc_buffer_add(&buf, keylen);
 197         dns_fixedname_init(&fixname);
 198         result = dns_name_fromtext(dns_fixedname_name(&fixname), &buf,
 199                                    dns_rootname, 0, NULL);
 200         if (result != ISC_R_SUCCESS) {
 201                 cfg_obj_log(keyobj, lctx, ISC_LOG_WARNING,
 202                             "key name '%s' is not a valid domain name",
 203                             txtname);
 204                 return (result);
 205         }
 206         return (dns_name_dup(dns_fixedname_name(&fixname), mctx, dnsname));
 207 }
 208
 209 /*
 210  * Recursively pre-parse an ACL definition to find the total number
 211  * of non-IP-prefix elements (localhost, localnets, key) in all nested
 212  * ACLs, so that the parent will have enough space allocated for the
 213  * elements table after all the nested ACLs have been merged in to the
 214  * parent.
 215  */
 216 static isc_result_t
 217 count_acl_elements(const cfg_obj_t *caml, const cfg_obj_t *cctx,
 218                    isc_log_t *lctx, cfg_aclconfctx_t *ctx, isc_mem_t *mctx,
 219                    isc_uint32_t *count, isc_boolean_t *has_negative)
 220 {
 221         const cfg_listelt_t *elt;
 222         isc_result_t result;
 223         isc_uint32_t n = 0;
 224
 225         REQUIRE(count != NULL);
 226
 227         if (has_negative != NULL)
 228                 *has_negative = ISC_FALSE;
 229
 230         for (elt = cfg_list_first(caml);
 231              elt != NULL;
 232              elt = cfg_list_next(elt)) {
 233                 const cfg_obj_t *ce = cfg_listelt_value(elt);
 234
 235                 /* negated element; just get the value. */
 236                 if (cfg_obj_istuple(ce)) {
 237                         ce = cfg_tuple_get(ce, "value");
 238                         if (has_negative != NULL)
 239                                 *has_negative = ISC_TRUE;
 240                 }
 241
 242                 if (cfg_obj_istype(ce, &cfg_type_keyref)) {
 243                         n++;
 244                 } else if (cfg_obj_islist(ce)) {
 245                         isc_boolean_t negative;
 246                         isc_uint32_t sub;
 247                         result = count_acl_elements(ce, cctx, lctx, ctx, mctx,
 248                                                     &sub, &negative);
 249                         if (result != ISC_R_SUCCESS)
 250                                 return (result);
 251                         n += sub;
 252                         if (negative)
 253                                 n++;
 254                 } else if (cfg_obj_isstring(ce)) {
 255                         const char *name = cfg_obj_asstring(ce);
 256                         if (strcasecmp(name, "localhost") == 0 ||
 257                             strcasecmp(name, "localnets") == 0 ||
 258                             strcasecmp(name, "none") == 0)
 259                         {
 260                                 n++;
 261                         } else if (strcasecmp(name, "any") != 0) {
 262                                 dns_acl_t *inneracl = NULL;
 263                                 /*
 264                                  * Convert any named acls we reference now if
 265                                  * they have not already been converted.
 266                                  */
 267                                 result = convert_named_acl(ce, cctx, lctx, ctx,
 268                                                            mctx, 0, &inneracl);
 269                                 if (result == ISC_R_SUCCESS) {
 270                                         if (inneracl->has_negatives)
 271                                                 n++;
 272                                         else
 273                                                 n += inneracl->length;
 274                                         dns_acl_detach(&inneracl);
 275                                 } else
 276                                         return (result);
 277                         }
 278                 }
 279         }
 280
 281         *count = n;
 282         return (ISC_R_SUCCESS);
 283 }
 284
 285 isc_result_t
 286 cfg_acl_fromconfig(const cfg_obj_t *caml, const cfg_obj_t *cctx,
 287                    isc_log_t *lctx, cfg_aclconfctx_t *ctx,
 288                    isc_mem_t *mctx, unsigned int nest_level,
 289                    dns_acl_t **target)
 290 {
 291         return (cfg_acl_fromconfig2(caml, cctx, lctx, ctx, mctx,
 292                                     nest_level, 0, target));
 293 }
 294
 295 isc_result_t
 296 cfg_acl_fromconfig2(const cfg_obj_t *caml, const cfg_obj_t *cctx,
 297                    isc_log_t *lctx, cfg_aclconfctx_t *ctx,
 298                    isc_mem_t *mctx, unsigned int nest_level,
 299                    isc_uint16_t family, dns_acl_t **target)
 300 {
 301         isc_result_t result;
 302         dns_acl_t *dacl = NULL, *inneracl = NULL;
 303         dns_aclelement_t *de;
 304         const cfg_listelt_t *elt;
 305         dns_iptable_t *iptab;
 306         int new_nest_level = 0;
 307
 308         if (nest_level != 0)
 309                 new_nest_level = nest_level - 1;
 310
 311         REQUIRE(target != NULL);
 312         REQUIRE(*target == NULL || DNS_ACL_VALID(*target));
 313
 314         if (*target != NULL) {
 315                 /*
 316                  * If target already points to an ACL, then we're being
 317                  * called recursively to configure a nested ACL.  The
 318                  * nested ACL's contents should just be absorbed into its
 319                  * parent ACL.
 320                  */
 321                 dns_acl_attach(*target, &dacl);
 322                 dns_acl_detach(target);
 323         } else {
 324                 /*
 325                  * Need to allocate a new ACL structure.  Count the items
 326                  * in the ACL definition that will require space in the
 327                  * elements table.  (Note that if nest_level is nonzero,
 328                  * *everything* goes in the elements table.)
 329                  */
 330                 isc_uint32_t nelem;
 331
 332                 if (nest_level == 0) {
 333                         result = count_acl_elements(caml, cctx, lctx, ctx,
 334                                                     mctx, &nelem, NULL);
 335                         if (result != ISC_R_SUCCESS)
 336                                 return (result);
 337                 } else
 338                         nelem = cfg_list_length(caml, ISC_FALSE);
 339
 340                 result = dns_acl_create(mctx, nelem, &dacl);
 341                 if (result != ISC_R_SUCCESS)
 342                         return (result);
 343         }
 344
 345         de = dacl->elements;
 346         for (elt = cfg_list_first(caml);
 347              elt != NULL;
 348              elt = cfg_list_next(elt)) {
 349                 const cfg_obj_t *ce = cfg_listelt_value(elt);
 350                 isc_boolean_t   neg;
 351
 352                 INSIST(dacl->length <= dacl->alloc);
 353
 354                 if (cfg_obj_istuple(ce)) {
 355                         /* This must be a negated element. */
 356                         ce = cfg_tuple_get(ce, "value");
 357                         neg = ISC_TRUE;
 358                         dacl->has_negatives = ISC_TRUE;
 359                 } else
 360                         neg = ISC_FALSE;
 361
 362                 /*
 363                  * If nest_level is nonzero, then every element is
 364                  * to be stored as a separate, nested ACL rather than
 365                  * merged into the main iptable.
 366                  */
 367                 iptab = dacl->iptable;
 368
 369                 if (nest_level != 0) {
 370                         result = dns_acl_create(mctx,
 371                                                 cfg_list_length(ce, ISC_FALSE),
 372                                                 &de->nestedacl);
 373                         if (result != ISC_R_SUCCESS)
 374                                 goto cleanup;
 375                         iptab = de->nestedacl->iptable;
 376                 }
 377
 378                 if (cfg_obj_isnetprefix(ce)) {
 379                         /* Network prefix */
 380                         isc_netaddr_t   addr;
 381                         unsigned int    bitlen;
 382
 383                         cfg_obj_asnetprefix(ce, &addr, &bitlen);
 384                         if (family != 0 && family != addr.family) {
 385                                 char buf[ISC_NETADDR_FORMATSIZE + 1];
 386                                 isc_netaddr_format(&addr, buf, sizeof(buf));
 387                                 cfg_obj_log(ce, lctx, ISC_LOG_WARNING,
 388                                             "'%s': incorrect address family; "
 389                                             "ignoring", buf);
 390                                 if (nest_level != 0)
 391                                         dns_acl_detach(&de->nestedacl);
 392                                 continue;
 393                         }
 394
 395                         /*
 396                          * If nesting ACLs (nest_level != 0), we negate
 397                          * the nestedacl element, not the iptable entry.
 398                          */
 399                         result = dns_iptable_addprefix(iptab, &addr, bitlen,
 400                                               ISC_TF(nest_level != 0 || !neg));
 401                         if (result != ISC_R_SUCCESS)
 402                                 goto cleanup;
 403
 404                         if (nest_level > 0) {
 405                                 INSIST(dacl->length < dacl->alloc);
 406                                 de->type = dns_aclelementtype_nestedacl;
 407                                 de->negative = neg;
 408                         } else
 409                                 continue;
 410                 } else if (cfg_obj_islist(ce)) {
 411                         /*
 412                          * If we're nesting ACLs, put the nested
 413                          * ACL onto the elements list; otherwise
 414                          * merge it into *this* ACL.  We nest ACLs
 415                          * in two cases: 1) sortlist, 2) if the
 416                          * nested ACL contains negated members.
 417                          */
 418                         if (inneracl != NULL)
 419                                 dns_acl_detach(&inneracl);
 420                         result = cfg_acl_fromconfig(ce, cctx, lctx,
 421                                                     ctx, mctx, new_nest_level,
 422                                                     &inneracl);
 423                         if (result != ISC_R_SUCCESS)
 424                                 goto cleanup;
 425 nested_acl:
 426                         if (nest_level > 0 || inneracl->has_negatives) {
 427                                 INSIST(dacl->length < dacl->alloc);
 428                                 de->type = dns_aclelementtype_nestedacl;
 429                                 de->negative = neg;
 430                                 if (de->nestedacl != NULL)
 431                                         dns_acl_detach(&de->nestedacl);
 432                                 dns_acl_attach(inneracl,
 433                                                &de->nestedacl);
 434                                 dns_acl_detach(&inneracl);
 435                                 /* Fall through. */
 436                         } else {
 437                                 INSIST(dacl->length + inneracl->length
 438                                        <= dacl->alloc);
 439                                 dns_acl_merge(dacl, inneracl,
 440                                               ISC_TF(!neg));
 441                                 de += inneracl->length;  /* elements added */
 442                                 dns_acl_detach(&inneracl);
 443                                 INSIST(dacl->length <= dacl->alloc);
 444                                 continue;
 445                         }
 446                 } else if (cfg_obj_istype(ce, &cfg_type_keyref)) {
 447                         /* Key name. */
 448                         INSIST(dacl->length < dacl->alloc);
 449                         de->type = dns_aclelementtype_keyname;
 450                         de->negative = neg;
 451                         dns_name_init(&de->keyname, NULL);
 452                         result = convert_keyname(ce, lctx, mctx,
 453                                                  &de->keyname);
 454                         if (result != ISC_R_SUCCESS)
 455                                 goto cleanup;
 456                 } else if (cfg_obj_isstring(ce)) {
 457                         /* ACL name. */
 458                         const char *name = cfg_obj_asstring(ce);
 459                         if (strcasecmp(name, "any") == 0) {
 460                                 /* Iptable entry with zero bit length. */
 461                                 result = dns_iptable_addprefix(iptab, NULL, 0,
 462                                               ISC_TF(nest_level != 0 || !neg));
 463                                 if (result != ISC_R_SUCCESS)
 464                                         goto cleanup;
 465
 466                                 if (nest_level != 0) {
 467                                         INSIST(dacl->length < dacl->alloc);
 468                                         de->type = dns_aclelementtype_nestedacl;
 469                                         de->negative = neg;
 470                                 } else
 471                                         continue;
 472                         } else if (strcasecmp(name, "none") == 0) {
 473                                 /* none == !any */
 474                                 /*
 475                                  * We don't unconditional set
 476                                  * dacl->has_negatives and
 477                                  * de->negative to true so we can handle
 478                                  * "!none;".
 479                                  */
 480                                 result = dns_iptable_addprefix(iptab, NULL, 0,
 481                                               ISC_TF(nest_level != 0 || neg));
 482                                 if (result != ISC_R_SUCCESS)
 483                                         goto cleanup;
 484
 485                                 if (!neg)
 486                                         dacl->has_negatives = !neg;
 487
 488                                 if (nest_level != 0) {
 489                                         INSIST(dacl->length < dacl->alloc);
 490                                         de->type = dns_aclelementtype_nestedacl;
 491                                         de->negative = !neg;
 492                                 } else
 493                                         continue;
 494                         } else if (strcasecmp(name, "localhost") == 0) {
 495                                 INSIST(dacl->length < dacl->alloc);
 496                                 de->type = dns_aclelementtype_localhost;
 497                                 de->negative = neg;
 498                         } else if (strcasecmp(name, "localnets") == 0) {
 499                                 INSIST(dacl->length < dacl->alloc);
 500                                 de->type = dns_aclelementtype_localnets;
 501                                 de->negative = neg;
 502                         } else {
 503                                 if (inneracl != NULL)
 504                                         dns_acl_detach(&inneracl);
 505                                 /*
 506                                  * This call should just find the cached
 507                                  * of the named acl.
 508                                  */
 509                                 result = convert_named_acl(ce, cctx, lctx, ctx,
 510                                                            mctx, new_nest_level,
 511                                                            &inneracl);
 512                                 if (result != ISC_R_SUCCESS)
 513                                         goto cleanup;
 514
 515                                 goto nested_acl;
 516                         }
 517                 } else {
 518                         cfg_obj_log(ce, lctx, ISC_LOG_WARNING,
 519                                     "address match list contains "
 520                                     "unsupported element type");
 521                         result = ISC_R_FAILURE;
 522                         goto cleanup;
 523                 }
 524
 525                 /*
 526                  * This should only be reached for localhost, localnets
 527                  * and keyname elements, and nested ACLs if nest_level is
 528                  * nonzero (i.e., in sortlists).
 529                  */
 530                 if (de->nestedacl != NULL &&
 531                     de->type != dns_aclelementtype_nestedacl)
 532                         dns_acl_detach(&de->nestedacl);
 533
 534                 dacl->node_count++;
 535                 de->node_num = dacl->node_count;
 536
 537                 dacl->length++;
 538                 de++;
 539                 INSIST(dacl->length <= dacl->alloc);
 540         }
 541
 542         dns_acl_attach(dacl, target);
 543         result = ISC_R_SUCCESS;
 544
 545  cleanup:
 546         if (inneracl != NULL)
 547                 dns_acl_detach(&inneracl);
 548         dns_acl_detach(&dacl);
 549         return (result);
 550 }