lib/isccfg/aclconf.c

   1 /*
   2  * Copyright (C) 2004-2010  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 1.27.62.2 2010/08/13 23:46:28 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 void
  37 cfg_aclconfctx_init(cfg_aclconfctx_t *ctx) {
  38         ISC_LIST_INIT(ctx->named_acl_cache);
  39 }
  40
  41 void
  42 cfg_aclconfctx_clear(cfg_aclconfctx_t *ctx) {
  43         dns_acl_t *dacl, *next;
  44
  45         for (dacl = ISC_LIST_HEAD(ctx->named_acl_cache);
  46              dacl != NULL;
  47              dacl = next)
  48         {
  49                 next = ISC_LIST_NEXT(dacl, nextincache);
  50                 dns_acl_detach(&dacl);
  51         }
  52 }
  53
  54 void
  55 cfg_aclconfctx_clone(cfg_aclconfctx_t *src, cfg_aclconfctx_t *dest) {
  56         dns_acl_t *dacl, *next;
  57         REQUIRE(src != NULL && dest != NULL);
  58
  59         cfg_aclconfctx_init(dest);
  60         for (dacl = ISC_LIST_HEAD(src->named_acl_cache);
  61              dacl != NULL;
  62              dacl = next)
  63         {
  64                 dns_acl_t *copy;
  65                 next = ISC_LIST_NEXT(dacl, nextincache);
  66                 dns_acl_attach(dacl, &copy);
  67                 ISC_LIST_APPEND(dest->named_acl_cache, copy, nextincache);
  68         }
  69 }
  70
  71 /*
  72  * Find the definition of the named acl whose name is "name".
  73  */
  74 static isc_result_t
  75 get_acl_def(const cfg_obj_t *cctx, const char *name, const cfg_obj_t **ret) {
  76         isc_result_t result;
  77         const cfg_obj_t *acls = NULL;
  78         const cfg_listelt_t *elt;
  79
  80         result = cfg_map_get(cctx, "acl", &acls);
  81         if (result != ISC_R_SUCCESS)
  82                 return (result);
  83         for (elt = cfg_list_first(acls);
  84              elt != NULL;
  85              elt = cfg_list_next(elt)) {
  86                 const cfg_obj_t *acl = cfg_listelt_value(elt);
  87                 const char *aclname = cfg_obj_asstring(cfg_tuple_get(acl, "name"));
  88                 if (strcasecmp(aclname, name) == 0) {
  89                         if (ret != NULL) {
  90                                 *ret = cfg_tuple_get(acl, "value");
  91                         }
  92                         return (ISC_R_SUCCESS);
  93                 }
  94         }
  95         return (ISC_R_NOTFOUND);
  96 }
  97
  98 static isc_result_t
  99 convert_named_acl(const cfg_obj_t *nameobj, const cfg_obj_t *cctx,
 100                   isc_log_t *lctx, cfg_aclconfctx_t *ctx,
 101                   isc_mem_t *mctx, unsigned int nest_level,
 102                   dns_acl_t **target)
 103 {
 104         isc_result_t result;
 105         const cfg_obj_t *cacl = NULL;
 106         dns_acl_t *dacl;
 107         dns_acl_t loop;
 108         const char *aclname = cfg_obj_asstring(nameobj);
 109
 110         /* Look for an already-converted version. */
 111         for (dacl = ISC_LIST_HEAD(ctx->named_acl_cache);
 112              dacl != NULL;
 113              dacl = ISC_LIST_NEXT(dacl, nextincache))
 114         {
 115                 if (strcasecmp(aclname, dacl->name) == 0) {
 116                         if (ISC_MAGIC_VALID(dacl, LOOP_MAGIC)) {
 117                                 cfg_obj_log(nameobj, lctx, ISC_LOG_ERROR,
 118                                             "acl loop detected: %s", aclname);
 119                                 return (ISC_R_FAILURE);
 120                         }
 121                         dns_acl_attach(dacl, target);
 122                         return (ISC_R_SUCCESS);
 123                 }
 124         }
 125         /* Not yet converted.  Convert now. */
 126         result = get_acl_def(cctx, aclname, &cacl);
 127         if (result != ISC_R_SUCCESS) {
 128                 cfg_obj_log(nameobj, lctx, ISC_LOG_WARNING,
 129                             "undefined ACL '%s'", aclname);
 130                 return (result);
 131         }
 132         /*
 133          * Add a loop detection element.
 134          */
 135         memset(&loop, 0, sizeof(loop));
 136         ISC_LINK_INIT(&loop, nextincache);
 137         DE_CONST(aclname, loop.name);
 138         loop.magic = LOOP_MAGIC;
 139         ISC_LIST_APPEND(ctx->named_acl_cache, &loop, nextincache);
 140         result = cfg_acl_fromconfig(cacl, cctx, lctx, ctx, mctx,
 141                                     nest_level, &dacl);
 142         ISC_LIST_UNLINK(ctx->named_acl_cache, &loop, nextincache);
 143         loop.magic = 0;
 144         loop.name = NULL;
 145         if (result != ISC_R_SUCCESS)
 146                 return (result);
 147         dacl->name = isc_mem_strdup(dacl->mctx, aclname);
 148         if (dacl->name == NULL)
 149                 return (ISC_R_NOMEMORY);
 150         ISC_LIST_APPEND(ctx->named_acl_cache, dacl, nextincache);
 151         dns_acl_attach(dacl, target);
 152         return (ISC_R_SUCCESS);
 153 }
 154
 155 static isc_result_t
 156 convert_keyname(const cfg_obj_t *keyobj, isc_log_t *lctx, isc_mem_t *mctx,
 157                 dns_name_t *dnsname)
 158 {
 159         isc_result_t result;
 160         isc_buffer_t buf;
 161         dns_fixedname_t fixname;
 162         unsigned int keylen;
 163         const char *txtname = cfg_obj_asstring(keyobj);
 164
 165         keylen = strlen(txtname);
 166         isc_buffer_init(&buf, txtname, keylen);
 167         isc_buffer_add(&buf, keylen);
 168         dns_fixedname_init(&fixname);
 169         result = dns_name_fromtext(dns_fixedname_name(&fixname), &buf,
 170                                    dns_rootname, 0, NULL);
 171         if (result != ISC_R_SUCCESS) {
 172                 cfg_obj_log(keyobj, lctx, ISC_LOG_WARNING,
 173                             "key name '%s' is not a valid domain name",
 174                             txtname);
 175                 return (result);
 176         }
 177         return (dns_name_dup(dns_fixedname_name(&fixname), mctx, dnsname));
 178 }
 179
 180 /*
 181  * Recursively pre-parse an ACL definition to find the total number
 182  * of non-IP-prefix elements (localhost, localnets, key) in all nested
 183  * ACLs, so that the parent will have enough space allocated for the
 184  * elements table after all the nested ACLs have been merged in to the
 185  * parent.
 186  */
 187 static int
 188 count_acl_elements(const cfg_obj_t *caml, const cfg_obj_t *cctx,
 189                    isc_boolean_t *has_negative)
 190 {
 191         const cfg_listelt_t *elt;
 192         const cfg_obj_t *cacl = NULL;
 193         isc_result_t result;
 194         int n = 0;
 195
 196         if (has_negative != NULL)
 197                 *has_negative = ISC_FALSE;
 198
 199         for (elt = cfg_list_first(caml);
 200              elt != NULL;
 201              elt = cfg_list_next(elt)) {
 202                 const cfg_obj_t *ce = cfg_listelt_value(elt);
 203
 204                 /* negated element; just get the value. */
 205                 if (cfg_obj_istuple(ce)) {
 206                         ce = cfg_tuple_get(ce, "value");
 207                         if (has_negative != NULL)
 208                                 *has_negative = ISC_TRUE;
 209                 }
 210
 211                 if (cfg_obj_istype(ce, &cfg_type_keyref)) {
 212                         n++;
 213                 } else if (cfg_obj_islist(ce)) {
 214                         isc_boolean_t negative;
 215                         n += count_acl_elements(ce, cctx, &negative);
 216                         if (negative)
 217                                 n++;
 218                 } else if (cfg_obj_isstring(ce)) {
 219                         const char *name = cfg_obj_asstring(ce);
 220                         if (strcasecmp(name, "localhost") == 0 ||
 221                             strcasecmp(name, "localnets") == 0) {
 222                                 n++;
 223                         } else if (strcasecmp(name, "any") != 0 &&
 224                                    strcasecmp(name, "none") != 0) {
 225                                 result = get_acl_def(cctx, name, &cacl);
 226                                 if (result == ISC_R_SUCCESS)
 227                                         n += count_acl_elements(cacl, cctx,
 228                                                                 NULL) + 1;
 229                         }
 230                 }
 231         }
 232
 233         return n;
 234 }
 235
 236 isc_result_t
 237 cfg_acl_fromconfig(const cfg_obj_t *caml,
 238                    const cfg_obj_t *cctx,
 239                    isc_log_t *lctx,
 240                    cfg_aclconfctx_t *ctx,
 241                    isc_mem_t *mctx,
 242                    unsigned int nest_level,
 243                    dns_acl_t **target)
 244 {
 245         isc_result_t result;
 246         dns_acl_t *dacl = NULL, *inneracl = NULL;
 247         dns_aclelement_t *de;
 248         const cfg_listelt_t *elt;
 249         dns_iptable_t *iptab;
 250         int new_nest_level = 0;
 251
 252         if (nest_level != 0)
 253                 new_nest_level = nest_level - 1;
 254
 255         REQUIRE(target != NULL);
 256         REQUIRE(*target == NULL || DNS_ACL_VALID(*target));
 257
 258         if (*target != NULL) {
 259                 /*
 260                  * If target already points to an ACL, then we're being
 261                  * called recursively to configure a nested ACL.  The
 262                  * nested ACL's contents should just be absorbed into its
 263                  * parent ACL.
 264                  */
 265                 dns_acl_attach(*target, &dacl);
 266                 dns_acl_detach(target);
 267         } else {
 268                 /*
 269                  * Need to allocate a new ACL structure.  Count the items
 270                  * in the ACL definition that will require space in the
 271                  * elements table.  (Note that if nest_level is nonzero,
 272                  * *everything* goes in the elements table.)
 273                  */
 274                 int nelem;
 275
 276                 if (nest_level == 0)
 277                         nelem = count_acl_elements(caml, cctx, NULL);
 278                 else
 279                         nelem = cfg_list_length(caml, ISC_FALSE);
 280
 281                 result = dns_acl_create(mctx, nelem, &dacl);
 282                 if (result != ISC_R_SUCCESS)
 283                         return (result);
 284         }
 285
 286         de = dacl->elements;
 287         for (elt = cfg_list_first(caml);
 288              elt != NULL;
 289              elt = cfg_list_next(elt)) {
 290                 const cfg_obj_t *ce = cfg_listelt_value(elt);
 291                 isc_boolean_t   neg;
 292
 293                 if (cfg_obj_istuple(ce)) {
 294                         /* This must be a negated element. */
 295                         ce = cfg_tuple_get(ce, "value");
 296                         neg = ISC_TRUE;
 297                         dacl->has_negatives = ISC_TRUE;
 298                 } else
 299                         neg = ISC_FALSE;
 300
 301                 /*
 302                  * If nest_level is nonzero, then every element is
 303                  * to be stored as a separate, nested ACL rather than
 304                  * merged into the main iptable.
 305                  */
 306                 iptab = dacl->iptable;
 307
 308                 if (nest_level != 0) {
 309                         result = dns_acl_create(mctx,
 310                                                 cfg_list_length(ce, ISC_FALSE),
 311                                                 &de->nestedacl);
 312                         if (result != ISC_R_SUCCESS)
 313                                 goto cleanup;
 314                         iptab = de->nestedacl->iptable;
 315                 }
 316
 317                 if (cfg_obj_isnetprefix(ce)) {
 318                         /* Network prefix */
 319                         isc_netaddr_t   addr;
 320                         unsigned int    bitlen;
 321
 322                         cfg_obj_asnetprefix(ce, &addr, &bitlen);
 323
 324                         /*
 325                          * If nesting ACLs (nest_level != 0), we negate
 326                          * the nestedacl element, not the iptable entry.
 327                          */
 328                         result = dns_iptable_addprefix(iptab, &addr, bitlen,
 329                                               ISC_TF(nest_level != 0 || !neg));
 330                         if (result != ISC_R_SUCCESS)
 331                                 goto cleanup;
 332
 333                         if (nest_level > 0) {
 334                                 de->type = dns_aclelementtype_nestedacl;
 335                                 de->negative = neg;
 336                         } else
 337                                 continue;
 338                 } else if (cfg_obj_islist(ce)) {
 339                         /*
 340                          * If we're nesting ACLs, put the nested
 341                          * ACL onto the elements list; otherwise
 342                          * merge it into *this* ACL.  We nest ACLs
 343                          * in two cases: 1) sortlist, 2) if the
 344                          * nested ACL contains negated members.
 345                          */
 346                         if (inneracl != NULL)
 347                                 dns_acl_detach(&inneracl);
 348                         result = cfg_acl_fromconfig(ce, cctx, lctx,
 349                                                     ctx, mctx, new_nest_level,
 350                                                     &inneracl);
 351                         if (result != ISC_R_SUCCESS)
 352                                 goto cleanup;
 353 nested_acl:
 354                         if (nest_level > 0 || inneracl->has_negatives) {
 355                                 de->type = dns_aclelementtype_nestedacl;
 356                                 de->negative = neg;
 357                                 if (de->nestedacl != NULL)
 358                                         dns_acl_detach(&de->nestedacl);
 359                                 dns_acl_attach(inneracl,
 360                                                &de->nestedacl);
 361                                 dns_acl_detach(&inneracl);
 362                                 /* Fall through. */
 363                         } else {
 364                                 dns_acl_merge(dacl, inneracl,
 365                                               ISC_TF(!neg));
 366                                 de += inneracl->length;  /* elements added */
 367                                 dns_acl_detach(&inneracl);
 368                                 continue;
 369                         }
 370                 } else if (cfg_obj_istype(ce, &cfg_type_keyref)) {
 371                         /* Key name. */
 372                         de->type = dns_aclelementtype_keyname;
 373                         de->negative = neg;
 374                         dns_name_init(&de->keyname, NULL);
 375                         result = convert_keyname(ce, lctx, mctx,
 376                                                  &de->keyname);
 377                         if (result != ISC_R_SUCCESS)
 378                                 goto cleanup;
 379                 } else if (cfg_obj_isstring(ce)) {
 380                         /* ACL name. */
 381                         const char *name = cfg_obj_asstring(ce);
 382                         if (strcasecmp(name, "any") == 0) {
 383                                 /* Iptable entry with zero bit length. */
 384                                 result = dns_iptable_addprefix(iptab, NULL, 0,
 385                                               ISC_TF(nest_level != 0 || !neg));
 386                                 if (result != ISC_R_SUCCESS)
 387                                         goto cleanup;
 388
 389                                 if (nest_level != 0) {
 390                                         de->type = dns_aclelementtype_nestedacl;
 391                                         de->negative = neg;
 392                                 } else
 393                                         continue;
 394                         } else if (strcasecmp(name, "none") == 0) {
 395                                 /* none == !any */
 396                                 /*
 397                                  * We don't unconditional set
 398                                  * dacl->has_negatives and
 399                                  * de->negative to true so we can handle
 400                                  * "!none;".
 401                                  */
 402                                 result = dns_iptable_addprefix(iptab, NULL, 0,
 403                                               ISC_TF(nest_level != 0 || neg));
 404                                 if (result != ISC_R_SUCCESS)
 405                                         goto cleanup;
 406
 407                                 if (!neg)
 408                                         dacl->has_negatives = !neg;
 409
 410                                 if (nest_level != 0) {
 411                                         de->type = dns_aclelementtype_nestedacl;
 412                                         de->negative = !neg;
 413                                 } else
 414                                         continue;
 415                         } else if (strcasecmp(name, "localhost") == 0) {
 416                                 de->type = dns_aclelementtype_localhost;
 417                                 de->negative = neg;
 418                         } else if (strcasecmp(name, "localnets") == 0) {
 419                                 de->type = dns_aclelementtype_localnets;
 420                                 de->negative = neg;
 421                         } else {
 422                                 if (inneracl != NULL)
 423                                         dns_acl_detach(&inneracl);
 424                                 result = convert_named_acl(ce, cctx, lctx, ctx,
 425                                                            mctx, new_nest_level,
 426                                                            &inneracl);
 427                                 if (result != ISC_R_SUCCESS)
 428                                         goto cleanup;
 429
 430                                 goto nested_acl;
 431                         }
 432                 } else {
 433                         cfg_obj_log(ce, lctx, ISC_LOG_WARNING,
 434                                     "address match list contains "
 435                                     "unsupported element type");
 436                         result = ISC_R_FAILURE;
 437                         goto cleanup;
 438                 }
 439
 440                 /*
 441                  * This should only be reached for localhost, localnets
 442                  * and keyname elements, and nested ACLs if nest_level is
 443                  * nonzero (i.e., in sortlists).
 444                  */
 445                 if (de->nestedacl != NULL &&
 446                     de->type != dns_aclelementtype_nestedacl)
 447                         dns_acl_detach(&de->nestedacl);
 448
 449                 dacl->node_count++;
 450                 de->node_num = dacl->node_count;
 451
 452                 dacl->length++;
 453                 de++;
 454                 INSIST(dacl->length <= dacl->alloc);
 455         }
 456
 457         dns_acl_attach(dacl, target);
 458         result = ISC_R_SUCCESS;
 459
 460  cleanup:
 461         if (inneracl != NULL)
 462                 dns_acl_detach(&inneracl);
 463         dns_acl_detach(&dacl);
 464         return (result);
 465 }