1/* 2 * Unix SMB/Netbios implementation. 3 * SEC_DESC handling functions 4 * Copyright (C) Jeremy R. Allison 1995-2003. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 3 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, see <http://www.gnu.org/licenses/>. 18 */ 19 20#include "includes.h" 21 22/******************************************************************* 23 Create the share security tdb. 24 ********************************************************************/ 25 26static struct db_context *share_db; /* used for share security descriptors */ 27#define SHARE_DATABASE_VERSION_V1 1 28#define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */ 29 30/* Map generic permissions to file object specific permissions */ 31 32extern const struct generic_mapping file_generic_mapping; 33 34static int delete_fn(struct db_record *rec, void *priv) 35{ 36 rec->delete_rec(rec); 37 return 0; 38} 39 40bool share_info_db_init(void) 41{ 42 const char *vstring = "INFO/version"; 43 int32 vers_id; 44 45 if (share_db != NULL) { 46 return True; 47 } 48 49 share_db = db_open(NULL, state_path("share_info.tdb"), 0, 50 TDB_DEFAULT, O_RDWR|O_CREAT, 0600); 51 if (share_db == NULL) { 52 DEBUG(0,("Failed to open share info database %s (%s)\n", 53 state_path("share_info.tdb"), strerror(errno) )); 54 return False; 55 } 56 57 vers_id = dbwrap_fetch_int32(share_db, vstring); 58 if (vers_id == SHARE_DATABASE_VERSION_V2) { 59 return true; 60 } 61 62 if (share_db->transaction_start(share_db) != 0) { 63 DEBUG(0, ("transaction_start failed\n")); 64 TALLOC_FREE(share_db); 65 return false; 66 } 67 68 vers_id = dbwrap_fetch_int32(share_db, vstring); 69 if (vers_id == SHARE_DATABASE_VERSION_V2) { 70 /* 71 * Race condition 72 */ 73 if (share_db->transaction_cancel(share_db)) { 74 smb_panic("transaction_cancel failed"); 75 } 76 return true; 77 } 78 79 /* Cope with byte-reversed older versions of the db. */ 80 if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) { 81 /* Written on a bigendian machine with old fetch_int code. Save as le. */ 82 83 if (dbwrap_store_int32(share_db, vstring, 84 SHARE_DATABASE_VERSION_V2) != 0) { 85 DEBUG(0, ("dbwrap_store_int32 failed\n")); 86 goto cancel; 87 } 88 vers_id = SHARE_DATABASE_VERSION_V2; 89 } 90 91 if (vers_id != SHARE_DATABASE_VERSION_V2) { 92 int ret; 93 ret = share_db->traverse(share_db, delete_fn, NULL); 94 if (ret < 0) { 95 DEBUG(0, ("traverse failed\n")); 96 goto cancel; 97 } 98 if (dbwrap_store_int32(share_db, vstring, 99 SHARE_DATABASE_VERSION_V2) != 0) { 100 DEBUG(0, ("dbwrap_store_int32 failed\n")); 101 goto cancel; 102 } 103 } 104 105 if (share_db->transaction_commit(share_db) != 0) { 106 DEBUG(0, ("transaction_commit failed\n")); 107 return false; 108 } 109 110 return true; 111 112 cancel: 113 if (share_db->transaction_cancel(share_db)) { 114 smb_panic("transaction_cancel failed"); 115 } 116 117 return false; 118} 119 120/******************************************************************* 121 Fake up a Everyone, default access as a default. 122 def_access is a GENERIC_XXX access mode. 123 ********************************************************************/ 124 125SEC_DESC *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access) 126{ 127 uint32_t sa; 128 SEC_ACE ace; 129 SEC_ACL *psa = NULL; 130 SEC_DESC *psd = NULL; 131 uint32 spec_access = def_access; 132 133 se_map_generic(&spec_access, &file_generic_mapping); 134 135 sa = (def_access | spec_access ); 136 init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0); 137 138 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) { 139 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1, 140 SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, 141 psa, psize); 142 } 143 144 if (!psd) { 145 DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n")); 146 return NULL; 147 } 148 149 return psd; 150} 151 152/******************************************************************* 153 Pull a security descriptor from the share tdb. 154 ********************************************************************/ 155 156SEC_DESC *get_share_security( TALLOC_CTX *ctx, const char *servicename, 157 size_t *psize) 158{ 159 char *key; 160 SEC_DESC *psd = NULL; 161 TDB_DATA data; 162 NTSTATUS status; 163 164 if (!share_info_db_init()) { 165 return NULL; 166 } 167 168 if (!(key = talloc_asprintf(ctx, "SECDESC/%s", servicename))) { 169 DEBUG(0, ("talloc_asprintf failed\n")); 170 return NULL; 171 } 172 173 data = dbwrap_fetch_bystring(share_db, talloc_tos(), key); 174 175 TALLOC_FREE(key); 176 177 if (data.dptr == NULL) { 178 return get_share_security_default(ctx, psize, 179 GENERIC_ALL_ACCESS); 180 } 181 182 status = unmarshall_sec_desc(ctx, data.dptr, data.dsize, &psd); 183 184 TALLOC_FREE(data.dptr); 185 186 if (!NT_STATUS_IS_OK(status)) { 187 DEBUG(0, ("unmarshall_sec_desc failed: %s\n", 188 nt_errstr(status))); 189 return NULL; 190 } 191 192 if (psd) 193 *psize = ndr_size_security_descriptor(psd, NULL, 0); 194 195 return psd; 196} 197 198/******************************************************************* 199 Store a security descriptor in the share db. 200 ********************************************************************/ 201 202bool set_share_security(const char *share_name, SEC_DESC *psd) 203{ 204 TALLOC_CTX *frame; 205 char *key; 206 bool ret = False; 207 TDB_DATA blob; 208 NTSTATUS status; 209 210 if (!share_info_db_init()) { 211 return False; 212 } 213 214 frame = talloc_stackframe(); 215 216 status = marshall_sec_desc(frame, psd, &blob.dptr, &blob.dsize); 217 218 if (!NT_STATUS_IS_OK(status)) { 219 DEBUG(0, ("marshall_sec_desc failed: %s\n", 220 nt_errstr(status))); 221 goto out; 222 } 223 224 if (!(key = talloc_asprintf(frame, "SECDESC/%s", share_name))) { 225 DEBUG(0, ("talloc_asprintf failed\n")); 226 goto out; 227 } 228 229 status = dbwrap_trans_store(share_db, string_term_tdb_data(key), blob, 230 TDB_REPLACE); 231 if (!NT_STATUS_IS_OK(status)) { 232 DEBUG(1, ("set_share_security: Failed to store secdesc for " 233 "%s: %s\n", share_name, nt_errstr(status))); 234 goto out; 235 } 236 237 DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name )); 238 ret = True; 239 240 out: 241 TALLOC_FREE(frame); 242 return ret; 243} 244 245/******************************************************************* 246 Delete a security descriptor. 247********************************************************************/ 248 249bool delete_share_security(const char *servicename) 250{ 251 TDB_DATA kbuf; 252 char *key; 253 NTSTATUS status; 254 255 if (!share_info_db_init()) { 256 return False; 257 } 258 259 if (!(key = talloc_asprintf(talloc_tos(), "SECDESC/%s", 260 servicename))) { 261 return False; 262 } 263 kbuf = string_term_tdb_data(key); 264 265 status = dbwrap_trans_delete(share_db, kbuf); 266 if (!NT_STATUS_IS_OK(status)) { 267 DEBUG(0, ("delete_share_security: Failed to delete entry for " 268 "share %s: %s\n", servicename, nt_errstr(status))); 269 return False; 270 } 271 272 return True; 273} 274 275/******************************************************************* 276 Can this user access with share with the required permissions ? 277********************************************************************/ 278 279bool share_access_check(const NT_USER_TOKEN *token, const char *sharename, 280 uint32 desired_access) 281{ 282 uint32 granted; 283 NTSTATUS status; 284 SEC_DESC *psd = NULL; 285 size_t sd_size; 286 287 psd = get_share_security(talloc_tos(), sharename, &sd_size); 288 289 if (!psd) { 290 return True; 291 } 292 293 status = se_access_check(psd, token, desired_access, &granted); 294 295 TALLOC_FREE(psd); 296 297 return NT_STATUS_IS_OK(status); 298} 299 300/*************************************************************************** 301 Parse the contents of an acl string from a usershare file. 302***************************************************************************/ 303 304bool parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, SEC_DESC **ppsd) 305{ 306 size_t s_size = 0; 307 const char *pacl = acl_str; 308 int num_aces = 0; 309 SEC_ACE *ace_list = NULL; 310 SEC_ACL *psa = NULL; 311 SEC_DESC *psd = NULL; 312 size_t sd_size = 0; 313 int i; 314 315 *ppsd = NULL; 316 317 /* If the acl string is blank return "Everyone:R" */ 318 if (!*acl_str) { 319 SEC_DESC *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS); 320 if (!default_psd) { 321 return False; 322 } 323 *ppsd = default_psd; 324 return True; 325 } 326 327 num_aces = 1; 328 329 /* Add the number of ',' characters to get the number of aces. */ 330 num_aces += count_chars(pacl,','); 331 332 ace_list = TALLOC_ARRAY(ctx, SEC_ACE, num_aces); 333 if (!ace_list) { 334 return False; 335 } 336 337 for (i = 0; i < num_aces; i++) { 338 uint32_t sa; 339 uint32 g_access; 340 uint32 s_access; 341 DOM_SID sid; 342 char *sidstr; 343 enum security_ace_type type = SEC_ACE_TYPE_ACCESS_ALLOWED; 344 345 if (!next_token_talloc(ctx, &pacl, &sidstr, ":")) { 346 DEBUG(0,("parse_usershare_acl: malformed usershare acl looking " 347 "for ':' in string '%s'\n", pacl)); 348 return False; 349 } 350 351 if (!string_to_sid(&sid, sidstr)) { 352 DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n", 353 sidstr )); 354 return False; 355 } 356 357 switch (*pacl) { 358 case 'F': /* Full Control, ie. R+W */ 359 case 'f': /* Full Control, ie. R+W */ 360 s_access = g_access = GENERIC_ALL_ACCESS; 361 break; 362 case 'R': /* Read only. */ 363 case 'r': /* Read only. */ 364 s_access = g_access = GENERIC_READ_ACCESS; 365 break; 366 case 'D': /* Deny all to this SID. */ 367 case 'd': /* Deny all to this SID. */ 368 type = SEC_ACE_TYPE_ACCESS_DENIED; 369 s_access = g_access = GENERIC_ALL_ACCESS; 370 break; 371 default: 372 DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n", 373 pacl )); 374 return False; 375 } 376 377 pacl++; 378 if (*pacl && *pacl != ',') { 379 DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n", 380 pacl )); 381 return False; 382 } 383 pacl++; /* Go past any ',' */ 384 385 se_map_generic(&s_access, &file_generic_mapping); 386 sa = (g_access | s_access); 387 init_sec_ace(&ace_list[i], &sid, type, sa, 0); 388 } 389 390 if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) { 391 psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1, 392 SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, 393 psa, &sd_size); 394 } 395 396 if (!psd) { 397 DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n")); 398 return False; 399 } 400 401 *ppsd = psd; 402 return True; 403} 404