contrib/bind9/lib/isccfg/aclconf.c

   1 /*
   2  * Copyright (C) 2004-2011  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: aclconf.c,v 1.29.72.2 2011-06-17 23:47:11 tbox Exp $ */
  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         isc_mem_t *mctx;
  78         unsigned int refs;
  79
  80         REQUIRE(actxp != NULL && *actxp != NULL);
  81
  82         actx = *actxp;
  83         mctx = actx->mctx;
  84
  85         isc_refcount_decrement(&actx->references, &refs);
  86         if (refs == 0) {
  87                 for (dacl = ISC_LIST_HEAD(actx->named_acl_cache);
  88                      dacl != NULL;
  89                      dacl = next)
  90                 {
  91                         next = ISC_LIST_NEXT(dacl, nextincache);
  92                         ISC_LIST_UNLINK(actx->named_acl_cache, dacl,
  93                                         nextincache);
  94                         dns_acl_detach(&dacl);
  95                 }
  96                 isc_mem_putanddetach(&actx->mctx, actx, sizeof(*actx));
  97         }
  98
  99         *actxp = NULL;
 100 }
 101
 102 /*
 103  * Find the definition of the named acl whose name is "name".
 104  */
 105 static isc_result_t
 106 get_acl_def(const cfg_obj_t *cctx, const char *name, const cfg_obj_t **ret) {
 107         isc_result_t result;
 108         const cfg_obj_t *acls = NULL;
 109         const cfg_listelt_t *elt;
 110
 111         result = cfg_map_get(cctx, "acl", &acls);
 112         if (result != ISC_R_SUCCESS)
 113                 return (result);
 114         for (elt = cfg_list_first(acls);
 115              elt != NULL;
 116              elt = cfg_list_next(elt)) {
 117                 const cfg_obj_t *acl = cfg_listelt_value(elt);
 118                 const char *aclname = cfg_obj_asstring(cfg_tuple_get(acl, "name"));
 119                 if (strcasecmp(aclname, name) == 0) {
 120                         if (ret != NULL) {
 121                                 *ret = cfg_tuple_get(acl, "value");
 122                         }
 123                         return (ISC_R_SUCCESS);
 124                 }
 125         }
 126         return (ISC_R_NOTFOUND);
 127 }
 128
 129 static isc_result_t
 130 convert_named_acl(const cfg_obj_t *nameobj, const cfg_obj_t *cctx,
 131                   isc_log_t *lctx, cfg_aclconfctx_t *ctx,
 132                   isc_mem_t *mctx, unsigned int nest_level,
 133                   dns_acl_t **target)
 134 {
 135         isc_result_t result;
 136         const cfg_obj_t *cacl = NULL;
 137         dns_acl_t *dacl;
 138         dns_acl_t loop;
 139         const char *aclname = cfg_obj_asstring(nameobj);
 140
 141         /* Look for an already-converted version. */
 142         for (dacl = ISC_LIST_HEAD(ctx->named_acl_cache);
 143              dacl != NULL;
 144              dacl = ISC_LIST_NEXT(dacl, nextincache))
 145         {
 146                 if (strcasecmp(aclname, dacl->name) == 0) {
 147                         if (ISC_MAGIC_VALID(dacl, LOOP_MAGIC)) {
 148                                 cfg_obj_log(nameobj, lctx, ISC_LOG_ERROR,
 149                                             "acl loop detected: %s", aclname);
 150                                 return (ISC_R_FAILURE);
 151                         }
 152                         dns_acl_attach(dacl, target);
 153                         return (ISC_R_SUCCESS);
 154                 }
 155         }
 156         /* Not yet converted.  Convert now. */
 157         result = get_acl_def(cctx, aclname, &cacl);
 158         if (result != ISC_R_SUCCESS) {
 159                 cfg_obj_log(nameobj, lctx, ISC_LOG_WARNING,
 160                             "undefined ACL '%s'", aclname);
 161                 return (result);
 162         }
 163         /*
 164          * Add a loop detection element.
 165          */
 166         memset(&loop, 0, sizeof(loop));
 167         ISC_LINK_INIT(&loop, nextincache);
 168         DE_CONST(aclname, loop.name);
 169         loop.magic = LOOP_MAGIC;
 170         ISC_LIST_APPEND(ctx->named_acl_cache, &loop, nextincache);
 171         result = cfg_acl_fromconfig(cacl, cctx, lctx, ctx, mctx,
 172                                     nest_level, &dacl);
 173         ISC_LIST_UNLINK(ctx->named_acl_cache, &loop, nextincache);
 174         loop.magic = 0;
 175         loop.name = NULL;
 176         if (result != ISC_R_SUCCESS)
 177                 return (result);
 178         dacl->name = isc_mem_strdup(dacl->mctx, aclname);
 179         if (dacl->name == NULL)
 180                 return (ISC_R_NOMEMORY);
 181         ISC_LIST_APPEND(ctx->named_acl_cache, dacl, nextincache);
 182         dns_acl_attach(dacl, target);
 183         return (ISC_R_SUCCESS);
 184 }
 185
 186 static isc_result_t
 187 convert_keyname(const cfg_obj_t *keyobj, isc_log_t *lctx, isc_mem_t *mctx,
 188                 dns_name_t *dnsname)
 189 {
 190         isc_result_t result;
 191         isc_buffer_t buf;
 192         dns_fixedname_t fixname;
 193         unsigned int keylen;
 194         const char *txtname = cfg_obj_asstring(keyobj);
 195
 196         keylen = strlen(txtname);
 197         isc_buffer_init(&buf, txtname, keylen);
 198         isc_buffer_add(&buf, keylen);
 199         dns_fixedname_init(&fixname);
 200         result = dns_name_fromtext(dns_fixedname_name(&fixname), &buf,
 201                                    dns_rootname, 0, NULL);
 202         if (result != ISC_R_SUCCESS) {
 203                 cfg_obj_log(keyobj, lctx, ISC_LOG_WARNING,
 204                             "key name '%s' is not a valid domain name",
 205                             txtname);
 206                 return (result);
 207         }
 208         return (dns_name_dup(dns_fixedname_name(&fixname), mctx, dnsname));
 209 }
 210
 211 /*
 212  * Recursively pre-parse an ACL definition to find the total number
 213  * of non-IP-prefix elements (localhost, localnets, key) in all nested
 214  * ACLs, so that the parent will have enough space allocated for the
 215  * elements table after all the nested ACLs have been merged in to the
 216  * parent.
 217  */
 218 static int
 219 count_acl_elements(const cfg_obj_t *caml, const cfg_obj_t *cctx,
 220                    isc_boolean_t *has_negative)
 221 {
 222         const cfg_listelt_t *elt;
 223         const cfg_obj_t *cacl = NULL;
 224         isc_result_t result;
 225         int n = 0;
 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                         n += count_acl_elements(ce, cctx, &negative);
 247                         if (negative)
 248                                 n++;
 249                 } else if (cfg_obj_isstring(ce)) {
 250                         const char *name = cfg_obj_asstring(ce);
 251                         if (strcasecmp(name, "localhost") == 0 ||
 252                             strcasecmp(name, "localnets") == 0) {
 253                                 n++;
 254                         } else if (strcasecmp(name, "any") != 0 &&
 255                                    strcasecmp(name, "none") != 0) {
 256                                 result = get_acl_def(cctx, name, &cacl);
 257                                 if (result == ISC_R_SUCCESS)
 258                                         n += count_acl_elements(cacl, cctx,
 259                                                                 NULL) + 1;
 260                         }
 261                 }
 262         }
 263
 264         return n;
 265 }
 266
 267 isc_result_t
 268 cfg_acl_fromconfig(const cfg_obj_t *caml,
 269                    const cfg_obj_t *cctx,
 270                    isc_log_t *lctx,
 271                    cfg_aclconfctx_t *ctx,
 272                    isc_mem_t *mctx,
 273                    unsigned int nest_level,
 274                    dns_acl_t **target)
 275 {
 276         isc_result_t result;
 277         dns_acl_t *dacl = NULL, *inneracl = NULL;
 278         dns_aclelement_t *de;
 279         const cfg_listelt_t *elt;
 280         dns_iptable_t *iptab;
 281         int new_nest_level = 0;
 282
 283         if (nest_level != 0)
 284                 new_nest_level = nest_level - 1;
 285
 286         REQUIRE(target != NULL);
 287         REQUIRE(*target == NULL || DNS_ACL_VALID(*target));
 288
 289         if (*target != NULL) {
 290                 /*
 291                  * If target already points to an ACL, then we're being
 292                  * called recursively to configure a nested ACL.  The
 293                  * nested ACL's contents should just be absorbed into its
 294                  * parent ACL.
 295                  */
 296                 dns_acl_attach(*target, &dacl);
 297                 dns_acl_detach(target);
 298         } else {
 299                 /*
 300                  * Need to allocate a new ACL structure.  Count the items
 301                  * in the ACL definition that will require space in the
 302                  * elements table.  (Note that if nest_level is nonzero,
 303                  * *everything* goes in the elements table.)
 304                  */
 305                 int nelem;
 306
 307                 if (nest_level == 0)
 308                         nelem = count_acl_elements(caml, cctx, NULL);
 309                 else
 310                         nelem = cfg_list_length(caml, ISC_FALSE);
 311
 312                 result = dns_acl_create(mctx, nelem, &dacl);
 313                 if (result != ISC_R_SUCCESS)
 314                         return (result);
 315         }
 316
 317         de = dacl->elements;
 318         for (elt = cfg_list_first(caml);
 319              elt != NULL;
 320              elt = cfg_list_next(elt)) {
 321                 const cfg_obj_t *ce = cfg_listelt_value(elt);
 322                 isc_boolean_t   neg;
 323
 324                 if (cfg_obj_istuple(ce)) {
 325                         /* This must be a negated element. */
 326                         ce = cfg_tuple_get(ce, "value");
 327                         neg = ISC_TRUE;
 328                         dacl->has_negatives = ISC_TRUE;
 329                 } else
 330                         neg = ISC_FALSE;
 331
 332                 /*
 333                  * If nest_level is nonzero, then every element is
 334                  * to be stored as a separate, nested ACL rather than
 335                  * merged into the main iptable.
 336                  */
 337                 iptab = dacl->iptable;
 338
 339                 if (nest_level != 0) {
 340                         result = dns_acl_create(mctx,
 341                                                 cfg_list_length(ce, ISC_FALSE),
 342                                                 &de->nestedacl);
 343                         if (result != ISC_R_SUCCESS)
 344                                 goto cleanup;
 345                         iptab = de->nestedacl->iptable;
 346                 }
 347
 348                 if (cfg_obj_isnetprefix(ce)) {
 349                         /* Network prefix */
 350                         isc_netaddr_t   addr;
 351                         unsigned int    bitlen;
 352
 353                         cfg_obj_asnetprefix(ce, &addr, &bitlen);
 354
 355                         /*
 356                          * If nesting ACLs (nest_level != 0), we negate
 357                          * the nestedacl element, not the iptable entry.
 358                          */
 359                         result = dns_iptable_addprefix(iptab, &addr, bitlen,
 360                                               ISC_TF(nest_level != 0 || !neg));
 361                         if (result != ISC_R_SUCCESS)
 362                                 goto cleanup;
 363
 364                         if (nest_level > 0) {
 365                                 de->type = dns_aclelementtype_nestedacl;
 366                                 de->negative = neg;
 367                         } else
 368                                 continue;
 369                 } else if (cfg_obj_islist(ce)) {
 370                         /*
 371                          * If we're nesting ACLs, put the nested
 372                          * ACL onto the elements list; otherwise
 373                          * merge it into *this* ACL.  We nest ACLs
 374                          * in two cases: 1) sortlist, 2) if the
 375                          * nested ACL contains negated members.
 376                          */
 377                         if (inneracl != NULL)
 378                                 dns_acl_detach(&inneracl);
 379                         result = cfg_acl_fromconfig(ce, cctx, lctx,
 380                                                     ctx, mctx, new_nest_level,
 381                                                     &inneracl);
 382                         if (result != ISC_R_SUCCESS)
 383                                 goto cleanup;
 384 nested_acl:
 385                         if (nest_level > 0 || inneracl->has_negatives) {
 386                                 de->type = dns_aclelementtype_nestedacl;
 387                                 de->negative = neg;
 388                                 if (de->nestedacl != NULL)
 389                                         dns_acl_detach(&de->nestedacl);
 390                                 dns_acl_attach(inneracl,
 391                                                &de->nestedacl);
 392                                 dns_acl_detach(&inneracl);
 393                                 /* Fall through. */
 394                         } else {
 395                                 dns_acl_merge(dacl, inneracl,
 396                                               ISC_TF(!neg));
 397                                 de += inneracl->length;  /* elements added */
 398                                 dns_acl_detach(&inneracl);
 399                                 continue;
 400                         }
 401                 } else if (cfg_obj_istype(ce, &cfg_type_keyref)) {
 402                         /* Key name. */
 403                         de->type = dns_aclelementtype_keyname;
 404                         de->negative = neg;
 405                         dns_name_init(&de->keyname, NULL);
 406                         result = convert_keyname(ce, lctx, mctx,
 407                                                  &de->keyname);
 408                         if (result != ISC_R_SUCCESS)
 409                                 goto cleanup;
 410                 } else if (cfg_obj_isstring(ce)) {
 411                         /* ACL name. */
 412                         const char *name = cfg_obj_asstring(ce);
 413                         if (strcasecmp(name, "any") == 0) {
 414                                 /* Iptable entry with zero bit length. */
 415                                 result = dns_iptable_addprefix(iptab, NULL, 0,
 416                                               ISC_TF(nest_level != 0 || !neg));
 417                                 if (result != ISC_R_SUCCESS)
 418                                         goto cleanup;
 419
 420                                 if (nest_level != 0) {
 421                                         de->type = dns_aclelementtype_nestedacl;
 422                                         de->negative = neg;
 423                                 } else
 424                                         continue;
 425                         } else if (strcasecmp(name, "none") == 0) {
 426                                 /* none == !any */
 427                                 /*
 428                                  * We don't unconditional set
 429                                  * dacl->has_negatives and
 430                                  * de->negative to true so we can handle
 431                                  * "!none;".
 432                                  */
 433                                 result = dns_iptable_addprefix(iptab, NULL, 0,
 434                                               ISC_TF(nest_level != 0 || neg));
 435                                 if (result != ISC_R_SUCCESS)
 436                                         goto cleanup;
 437
 438                                 if (!neg)
 439                                         dacl->has_negatives = !neg;
 440
 441                                 if (nest_level != 0) {
 442                                         de->type = dns_aclelementtype_nestedacl;
 443                                         de->negative = !neg;
 444                                 } else
 445                                         continue;
 446                         } else if (strcasecmp(name, "localhost") == 0) {
 447                                 de->type = dns_aclelementtype_localhost;
 448                                 de->negative = neg;
 449                         } else if (strcasecmp(name, "localnets") == 0) {
 450                                 de->type = dns_aclelementtype_localnets;
 451                                 de->negative = neg;
 452                         } else {
 453                                 if (inneracl != NULL)
 454                                         dns_acl_detach(&inneracl);
 455                                 result = convert_named_acl(ce, cctx, lctx, ctx,
 456                                                            mctx, new_nest_level,
 457                                                            &inneracl);
 458                                 if (result != ISC_R_SUCCESS)
 459                                         goto cleanup;
 460
 461                                 goto nested_acl;
 462                         }
 463                 } else {
 464                         cfg_obj_log(ce, lctx, ISC_LOG_WARNING,
 465                                     "address match list contains "
 466                                     "unsupported element type");
 467                         result = ISC_R_FAILURE;
 468                         goto cleanup;
 469                 }
 470
 471                 /*
 472                  * This should only be reached for localhost, localnets
 473                  * and keyname elements, and nested ACLs if nest_level is
 474                  * nonzero (i.e., in sortlists).
 475                  */
 476                 if (de->nestedacl != NULL &&
 477                     de->type != dns_aclelementtype_nestedacl)
 478                         dns_acl_detach(&de->nestedacl);
 479
 480                 dacl->node_count++;
 481                 de->node_num = dacl->node_count;
 482
 483                 dacl->length++;
 484                 de++;
 485                 INSIST(dacl->length <= dacl->alloc);
 486         }
 487
 488         dns_acl_attach(dacl, target);
 489         result = ISC_R_SUCCESS;
 490
 491  cleanup:
 492         if (inneracl != NULL)
 493                 dns_acl_detach(&inneracl);
 494         dns_acl_detach(&dacl);
 495         return (result);
 496 }