contrib/bind9/lib/isccfg/aclconf.c

   1 /*
   2  * Copyright (C) 2004-2009  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 1.22.34.4 2009/10/01 23:47:17 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_destroy(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 /*
  55  * Find the definition of the named acl whose name is "name".
  56  */
  57 static isc_result_t
  58 get_acl_def(const cfg_obj_t *cctx, const char *name, const cfg_obj_t **ret) {
  59         isc_result_t result;
  60         const cfg_obj_t *acls = NULL;
  61         const cfg_listelt_t *elt;
  62
  63         result = cfg_map_get(cctx, "acl", &acls);
  64         if (result != ISC_R_SUCCESS)
  65                 return (result);
  66         for (elt = cfg_list_first(acls);
  67              elt != NULL;
  68              elt = cfg_list_next(elt)) {
  69                 const cfg_obj_t *acl = cfg_listelt_value(elt);
  70                 const char *aclname = cfg_obj_asstring(cfg_tuple_get(acl, "name"));
  71                 if (strcasecmp(aclname, name) == 0) {
  72                         if (ret != NULL) {
  73                                 *ret = cfg_tuple_get(acl, "value");
  74                         }
  75                         return (ISC_R_SUCCESS);
  76                 }
  77         }
  78         return (ISC_R_NOTFOUND);
  79 }
  80
  81 static isc_result_t
  82 convert_named_acl(const cfg_obj_t *nameobj, const cfg_obj_t *cctx,
  83                   isc_log_t *lctx, cfg_aclconfctx_t *ctx,
  84                   isc_mem_t *mctx, unsigned int nest_level,
  85                   dns_acl_t **target)
  86 {
  87         isc_result_t result;
  88         const cfg_obj_t *cacl = NULL;
  89         dns_acl_t *dacl;
  90         dns_acl_t loop;
  91         const char *aclname = cfg_obj_asstring(nameobj);
  92
  93         /* Look for an already-converted version. */
  94         for (dacl = ISC_LIST_HEAD(ctx->named_acl_cache);
  95              dacl != NULL;
  96              dacl = ISC_LIST_NEXT(dacl, nextincache))
  97         {
  98                 if (strcasecmp(aclname, dacl->name) == 0) {
  99                         if (ISC_MAGIC_VALID(dacl, LOOP_MAGIC)) {
 100                                 cfg_obj_log(nameobj, lctx, ISC_LOG_ERROR,
 101                                             "acl loop detected: %s", aclname);
 102                                 return (ISC_R_FAILURE);
 103                         }
 104                         dns_acl_attach(dacl, target);
 105                         return (ISC_R_SUCCESS);
 106                 }
 107         }
 108         /* Not yet converted.  Convert now. */
 109         result = get_acl_def(cctx, aclname, &cacl);
 110         if (result != ISC_R_SUCCESS) {
 111                 cfg_obj_log(nameobj, lctx, ISC_LOG_WARNING,
 112                             "undefined ACL '%s'", aclname);
 113                 return (result);
 114         }
 115         /*
 116          * Add a loop detection element.
 117          */
 118         memset(&loop, 0, sizeof(loop));
 119         ISC_LINK_INIT(&loop, nextincache);
 120         DE_CONST(aclname, loop.name);
 121         loop.magic = LOOP_MAGIC;
 122         ISC_LIST_APPEND(ctx->named_acl_cache, &loop, nextincache);
 123         result = cfg_acl_fromconfig(cacl, cctx, lctx, ctx, mctx,
 124                                     nest_level, &dacl);
 125         ISC_LIST_UNLINK(ctx->named_acl_cache, &loop, nextincache);
 126         loop.magic = 0;
 127         loop.name = NULL;
 128         if (result != ISC_R_SUCCESS)
 129                 return (result);
 130         dacl->name = isc_mem_strdup(dacl->mctx, aclname);
 131         if (dacl->name == NULL)
 132                 return (ISC_R_NOMEMORY);
 133         ISC_LIST_APPEND(ctx->named_acl_cache, dacl, nextincache);
 134         dns_acl_attach(dacl, target);
 135         return (ISC_R_SUCCESS);
 136 }
 137
 138 static isc_result_t
 139 convert_keyname(const cfg_obj_t *keyobj, isc_log_t *lctx, isc_mem_t *mctx,
 140                 dns_name_t *dnsname)
 141 {
 142         isc_result_t result;
 143         isc_buffer_t buf;
 144         dns_fixedname_t fixname;
 145         unsigned int keylen;
 146         const char *txtname = cfg_obj_asstring(keyobj);
 147
 148         keylen = strlen(txtname);
 149         isc_buffer_init(&buf, txtname, keylen);
 150         isc_buffer_add(&buf, keylen);
 151         dns_fixedname_init(&fixname);
 152         result = dns_name_fromtext(dns_fixedname_name(&fixname), &buf,
 153                                    dns_rootname, ISC_FALSE, NULL);
 154         if (result != ISC_R_SUCCESS) {
 155                 cfg_obj_log(keyobj, lctx, ISC_LOG_WARNING,
 156                             "key name '%s' is not a valid domain name",
 157                             txtname);
 158                 return (result);
 159         }
 160         return (dns_name_dup(dns_fixedname_name(&fixname), mctx, dnsname));
 161 }
 162
 163 /*
 164  * Recursively pre-parse an ACL definition to find the total number
 165  * of non-IP-prefix elements (localhost, localnets, key) in all nested
 166  * ACLs, so that the parent will have enough space allocated for the
 167  * elements table after all the nested ACLs have been merged in to the
 168  * parent.
 169  */
 170 static int
 171 count_acl_elements(const cfg_obj_t *caml, const cfg_obj_t *cctx,
 172                    isc_boolean_t *has_negative)
 173 {
 174         const cfg_listelt_t *elt;
 175         const cfg_obj_t *cacl = NULL;
 176         isc_result_t result;
 177         int n = 0;
 178
 179         if (has_negative != NULL)
 180                 *has_negative = ISC_FALSE;
 181
 182         for (elt = cfg_list_first(caml);
 183              elt != NULL;
 184              elt = cfg_list_next(elt)) {
 185                 const cfg_obj_t *ce = cfg_listelt_value(elt);
 186
 187                 /* negated element; just get the value. */
 188                 if (cfg_obj_istuple(ce)) {
 189                         ce = cfg_tuple_get(ce, "value");
 190                         if (has_negative != NULL)
 191                                 *has_negative = ISC_TRUE;
 192                 }
 193
 194                 if (cfg_obj_istype(ce, &cfg_type_keyref)) {
 195                         n++;
 196                 } else if (cfg_obj_islist(ce)) {
 197                         isc_boolean_t negative;
 198                         n += count_acl_elements(ce, cctx, &negative);
 199                         if (negative)
 200                                 n++;
 201                 } else if (cfg_obj_isstring(ce)) {
 202                         const char *name = cfg_obj_asstring(ce);
 203                         if (strcasecmp(name, "localhost") == 0 ||
 204                             strcasecmp(name, "localnets") == 0) {
 205                                 n++;
 206                         } else if (strcasecmp(name, "any") != 0 &&
 207                                    strcasecmp(name, "none") != 0) {
 208                                 result = get_acl_def(cctx, name, &cacl);
 209                                 if (result == ISC_R_SUCCESS)
 210                                         n += count_acl_elements(cacl, cctx,
 211                                                                 NULL) + 1;
 212                         }
 213                 }
 214         }
 215
 216         return n;
 217 }
 218
 219 isc_result_t
 220 cfg_acl_fromconfig(const cfg_obj_t *caml,
 221                    const cfg_obj_t *cctx,
 222                    isc_log_t *lctx,
 223                    cfg_aclconfctx_t *ctx,
 224                    isc_mem_t *mctx,
 225                    unsigned int nest_level,
 226                    dns_acl_t **target)
 227 {
 228         isc_result_t result;
 229         dns_acl_t *dacl = NULL, *inneracl = NULL;
 230         dns_aclelement_t *de;
 231         const cfg_listelt_t *elt;
 232         dns_iptable_t *iptab;
 233         int new_nest_level = 0;
 234
 235         if (nest_level != 0)
 236                 new_nest_level = nest_level - 1;
 237
 238         REQUIRE(target != NULL);
 239         REQUIRE(*target == NULL || DNS_ACL_VALID(*target));
 240
 241         if (*target != NULL) {
 242                 /*
 243                  * If target already points to an ACL, then we're being
 244                  * called recursively to configure a nested ACL.  The
 245                  * nested ACL's contents should just be absorbed into its
 246                  * parent ACL.
 247                  */
 248                 dns_acl_attach(*target, &dacl);
 249                 dns_acl_detach(target);
 250         } else {
 251                 /*
 252                  * Need to allocate a new ACL structure.  Count the items
 253                  * in the ACL definition that will require space in the
 254                  * elements table.  (Note that if nest_level is nonzero,
 255                  * *everything* goes in the elements table.)
 256                  */
 257                 int nelem;
 258
 259                 if (nest_level == 0)
 260                         nelem = count_acl_elements(caml, cctx, NULL);
 261                 else
 262                         nelem = cfg_list_length(caml, ISC_FALSE);
 263
 264                 result = dns_acl_create(mctx, nelem, &dacl);
 265                 if (result != ISC_R_SUCCESS)
 266                         return (result);
 267         }
 268
 269         de = dacl->elements;
 270         for (elt = cfg_list_first(caml);
 271              elt != NULL;
 272              elt = cfg_list_next(elt)) {
 273                 const cfg_obj_t *ce = cfg_listelt_value(elt);
 274                 isc_boolean_t   neg;
 275
 276                 if (cfg_obj_istuple(ce)) {
 277                         /* This must be a negated element. */
 278                         ce = cfg_tuple_get(ce, "value");
 279                         neg = ISC_TRUE;
 280                         dacl->has_negatives = ISC_TRUE;
 281                 } else
 282                         neg = ISC_FALSE;
 283
 284                 /*
 285                  * If nest_level is nonzero, then every element is
 286                  * to be stored as a separate, nested ACL rather than
 287                  * merged into the main iptable.
 288                  */
 289                 iptab = dacl->iptable;
 290
 291                 if (nest_level != 0) {
 292                         result = dns_acl_create(mctx,
 293                                                 cfg_list_length(ce, ISC_FALSE),
 294                                                 &de->nestedacl);
 295                         if (result != ISC_R_SUCCESS)
 296                                 goto cleanup;
 297                         iptab = de->nestedacl->iptable;
 298                 }
 299
 300                 if (cfg_obj_isnetprefix(ce)) {
 301                         /* Network prefix */
 302                         isc_netaddr_t   addr;
 303                         unsigned int    bitlen;
 304
 305                         cfg_obj_asnetprefix(ce, &addr, &bitlen);
 306
 307                         /*
 308                          * If nesting ACLs (nest_level != 0), we negate
 309                          * the nestedacl element, not the iptable entry.
 310                          */
 311                         result = dns_iptable_addprefix(iptab, &addr, bitlen,
 312                                               ISC_TF(nest_level != 0 || !neg));
 313                         if (result != ISC_R_SUCCESS)
 314                                 goto cleanup;
 315
 316                         if (nest_level > 0) {
 317                                 de->type = dns_aclelementtype_nestedacl;
 318                                 de->negative = neg;
 319                         } else
 320                                 continue;
 321                 } else if (cfg_obj_islist(ce)) {
 322                         /*
 323                          * If we're nesting ACLs, put the nested
 324                          * ACL onto the elements list; otherwise
 325                          * merge it into *this* ACL.  We nest ACLs
 326                          * in two cases: 1) sortlist, 2) if the
 327                          * nested ACL contains negated members.
 328                          */
 329                         if (inneracl != NULL)
 330                                 dns_acl_detach(&inneracl);
 331                         result = cfg_acl_fromconfig(ce, cctx, lctx,
 332                                                     ctx, mctx, new_nest_level,
 333                                                     &inneracl);
 334                         if (result != ISC_R_SUCCESS)
 335                                 goto cleanup;
 336 nested_acl:
 337                         if (nest_level > 0 || inneracl->has_negatives) {
 338                                 de->type = dns_aclelementtype_nestedacl;
 339                                 de->negative = neg;
 340                                 if (de->nestedacl != NULL)
 341                                         dns_acl_detach(&de->nestedacl);
 342                                 dns_acl_attach(inneracl,
 343                                                &de->nestedacl);
 344                                 dns_acl_detach(&inneracl);
 345                                 /* Fall through. */
 346                         } else {
 347                                 dns_acl_merge(dacl, inneracl,
 348                                               ISC_TF(!neg));
 349                                 de += inneracl->length;  /* elements added */
 350                                 dns_acl_detach(&inneracl);
 351                                 continue;
 352                         }
 353                 } else if (cfg_obj_istype(ce, &cfg_type_keyref)) {
 354                         /* Key name. */
 355                         de->type = dns_aclelementtype_keyname;
 356                         de->negative = neg;
 357                         dns_name_init(&de->keyname, NULL);
 358                         result = convert_keyname(ce, lctx, mctx,
 359                                                  &de->keyname);
 360                         if (result != ISC_R_SUCCESS)
 361                                 goto cleanup;
 362                 } else if (cfg_obj_isstring(ce)) {
 363                         /* ACL name. */
 364                         const char *name = cfg_obj_asstring(ce);
 365                         if (strcasecmp(name, "any") == 0) {
 366                                 /* Iptable entry with zero bit length. */
 367                                 result = dns_iptable_addprefix(iptab, NULL, 0,
 368                                               ISC_TF(nest_level != 0 || !neg));
 369                                 if (result != ISC_R_SUCCESS)
 370                                         goto cleanup;
 371
 372                                 if (nest_level != 0) {
 373                                         de->type = dns_aclelementtype_nestedacl;
 374                                         de->negative = neg;
 375                                 } else
 376                                         continue;
 377                         } else if (strcasecmp(name, "none") == 0) {
 378                                 /* none == !any */
 379                                 /*
 380                                  * We don't unconditional set
 381                                  * dacl->has_negatives and
 382                                  * de->negative to true so we can handle
 383                                  * "!none;".
 384                                  */
 385                                 result = dns_iptable_addprefix(iptab, NULL, 0,
 386                                               ISC_TF(nest_level != 0 || neg));
 387                                 if (result != ISC_R_SUCCESS)
 388                                         goto cleanup;
 389
 390                                 if (!neg)
 391                                         dacl->has_negatives = !neg;
 392
 393                                 if (nest_level != 0) {
 394                                         de->type = dns_aclelementtype_nestedacl;
 395                                         de->negative = !neg;
 396                                 } else
 397                                         continue;
 398                         } else if (strcasecmp(name, "localhost") == 0) {
 399                                 de->type = dns_aclelementtype_localhost;
 400                                 de->negative = neg;
 401                         } else if (strcasecmp(name, "localnets") == 0) {
 402                                 de->type = dns_aclelementtype_localnets;
 403                                 de->negative = neg;
 404                         } else {
 405                                 if (inneracl != NULL)
 406                                         dns_acl_detach(&inneracl);
 407                                 result = convert_named_acl(ce, cctx, lctx, ctx,
 408                                                            mctx, new_nest_level,
 409                                                            &inneracl);
 410                                 if (result != ISC_R_SUCCESS)
 411                                         goto cleanup;
 412
 413                                 goto nested_acl;
 414                         }
 415                 } else {
 416                         cfg_obj_log(ce, lctx, ISC_LOG_WARNING,
 417                                     "address match list contains "
 418                                     "unsupported element type");
 419                         result = ISC_R_FAILURE;
 420                         goto cleanup;
 421                 }
 422
 423                 /*
 424                  * This should only be reached for localhost, localnets
 425                  * and keyname elements, and nested ACLs if nest_level is
 426                  * nonzero (i.e., in sortlists).
 427                  */
 428                 if (de->nestedacl != NULL &&
 429                     de->type != dns_aclelementtype_nestedacl)
 430                         dns_acl_detach(&de->nestedacl);
 431
 432                 dacl->node_count++;
 433                 de->node_num = dacl->node_count;
 434
 435                 dacl->length++;
 436                 de++;
 437                 INSIST(dacl->length <= dacl->alloc);
 438         }
 439
 440         dns_acl_attach(dacl, target);
 441         result = ISC_R_SUCCESS;
 442
 443  cleanup:
 444         if (inneracl != NULL)
 445                 dns_acl_detach(&inneracl);
 446         dns_acl_detach(&dacl);
 447         return (result);
 448 }