| 1 | /************************************************* |
| 2 | * Exim - an Internet mail transport agent * |
| 3 | *************************************************/ |
| 4 | |
| 5 | /* Copyright (c) University of Cambridge 1995 - 2015 */ |
| 6 | /* See the file NOTICE for conditions of use and distribution. */ |
| 7 | |
| 8 | /* A set of functions to search databases in various formats. An open |
| 9 | database is represented by a void * value which is returned from a lookup- |
| 10 | specific "open" function. These are now all held in individual modules in the |
| 11 | lookups subdirectory and the functions here form a generic interface. |
| 12 | |
| 13 | Caching is used to improve performance. Open files are cached until a tidyup |
| 14 | function is called, and for each file the result of the last lookup is cached. |
| 15 | However, if too many files are opened, some of those that are not in use have |
| 16 | to be closed. Those open items that use real files are kept on a LRU chain to |
| 17 | help with this. |
| 18 | |
| 19 | All the data is held in permanent store so as to be independent of the stacking |
| 20 | pool that is reset from time to time. In fact, we use malloc'd store so that it |
| 21 | can be freed when the caches are tidied up. It isn't actually clear whether |
| 22 | this is a benefit or not, to be honest. */ |
| 23 | |
| 24 | #include "exim.h" |
| 25 | |
| 26 | |
| 27 | /* Tree in which to cache open files until tidyup called. */ |
| 28 | |
| 29 | static tree_node *search_tree = NULL; |
| 30 | |
| 31 | /* Two-way chain of open databases that use real files. This is maintained in |
| 32 | recently-used order for the purposes of closing the least recently used when |
| 33 | too many files are open. */ |
| 34 | |
| 35 | static tree_node *open_top = NULL; |
| 36 | static tree_node *open_bot = NULL; |
| 37 | |
| 38 | /* Count of open databases that use real files */ |
| 39 | |
| 40 | static int open_filecount = 0; |
| 41 | |
| 42 | /* Allow us to reset store used for lookups and lookup caching */ |
| 43 | |
| 44 | static rmark search_reset_point = NULL; |
| 45 | |
| 46 | |
| 47 | |
| 48 | /************************************************* |
| 49 | * Validate a plain lookup type name * |
| 50 | *************************************************/ |
| 51 | |
| 52 | /* Only those names that are recognized and whose code is included in the |
| 53 | binary give an OK response. Use a binary chop search now that the list has got |
| 54 | so long. |
| 55 | |
| 56 | Arguments: |
| 57 | name lookup type name - not necessarily zero terminated (e.g. dbm*) |
| 58 | len length of the name |
| 59 | |
| 60 | Returns: +ve => valid lookup name; value is offset in lookup_list |
| 61 | -ve => invalid name; message in search_error_message. |
| 62 | */ |
| 63 | |
| 64 | int |
| 65 | search_findtype(const uschar *name, int len) |
| 66 | { |
| 67 | int bot = 0; |
| 68 | int top = lookup_list_count; |
| 69 | while (top > bot) |
| 70 | { |
| 71 | int mid = (top + bot)/2; |
| 72 | int c = Ustrncmp(name, lookup_list[mid]->name, len); |
| 73 | |
| 74 | /* If c == 0 we have matched the incoming name with the start of the search |
| 75 | type name. However, some search types are substrings of others (e.g. nis and |
| 76 | nisplus) so we need to check that the lengths are the same. The length of the |
| 77 | type name cannot be shorter (else c would not be 0); if it is not equal it |
| 78 | must be longer, and in that case, the incoming name comes before the name we |
| 79 | are testing. By leaving c == 0 when the lengths are different, and doing a |
| 80 | > 0 test below, this all falls out correctly. */ |
| 81 | |
| 82 | if (c == 0 && Ustrlen(lookup_list[mid]->name) == len) |
| 83 | { |
| 84 | if (lookup_list[mid]->find != NULL) return mid; |
| 85 | search_error_message = string_sprintf("lookup type \"%.*s\" is not " |
| 86 | "available (not in the binary - check buildtime LOOKUP configuration)", |
| 87 | len, name); |
| 88 | return -1; |
| 89 | } |
| 90 | |
| 91 | if (c > 0) bot = mid + 1; else top = mid; |
| 92 | } |
| 93 | |
| 94 | search_error_message = string_sprintf("unknown lookup type \"%.*s\"",len,name); |
| 95 | return -1; |
| 96 | } |
| 97 | |
| 98 | |
| 99 | |
| 100 | /************************************************* |
| 101 | * Validate a full lookup type name * |
| 102 | *************************************************/ |
| 103 | |
| 104 | /* This function recognizes the "partial-" prefix and also terminating * and *@ |
| 105 | suffixes. |
| 106 | |
| 107 | Arguments: |
| 108 | name the full lookup type name |
| 109 | ptypeptr where to put the partial type |
| 110 | after subtraction of 1024 or 2048: |
| 111 | negative => no partial matching |
| 112 | non-negative => minimum number of non-wild components |
| 113 | ptypeaff where to put a pointer to the affix |
| 114 | the affix is within name if supplied therein |
| 115 | otherwise it's a literal string |
| 116 | afflen the length of the affix |
| 117 | starflags where to put the SEARCH_STAR and SEARCH_STARAT flags |
| 118 | opts where to put the options |
| 119 | |
| 120 | Returns: +ve => valid lookup name; value is offset in lookup_list |
| 121 | -ve => invalid name; message in search_error_message. |
| 122 | */ |
| 123 | |
| 124 | int |
| 125 | search_findtype_partial(const uschar *name, int *ptypeptr, const uschar **ptypeaff, |
| 126 | int *afflen, int *starflags, const uschar ** opts) |
| 127 | { |
| 128 | int len, stype; |
| 129 | int pv = -1; |
| 130 | const uschar *ss = name; |
| 131 | const uschar * t; |
| 132 | |
| 133 | *starflags = 0; |
| 134 | *ptypeaff = NULL; |
| 135 | |
| 136 | /* Check for a partial matching type. It must start with "partial", optionally |
| 137 | followed by a sequence of digits. If this is followed by "-", the affix is the |
| 138 | default "*." string. Otherwise we expect an affix in parentheses. Affixes are a |
| 139 | limited number of characters, not including parens. */ |
| 140 | |
| 141 | if (Ustrncmp(name, "partial", 7) == 0) |
| 142 | { |
| 143 | ss += 7; |
| 144 | if (isdigit (*ss)) |
| 145 | { |
| 146 | pv = 0; |
| 147 | while (isdigit(*ss)) pv = pv*10 + *ss++ - '0'; |
| 148 | } |
| 149 | else pv = 2; /* Default number of wild components */ |
| 150 | |
| 151 | if (*ss == '(') |
| 152 | { |
| 153 | *ptypeaff = ++ss; |
| 154 | while (ispunct(*ss) && *ss != ')') ss++; |
| 155 | if (*ss != ')') goto BAD_TYPE; |
| 156 | *afflen = ss++ - *ptypeaff; |
| 157 | } |
| 158 | else if (*ss++ == '-') |
| 159 | { |
| 160 | *ptypeaff = US "*."; |
| 161 | *afflen = 2; |
| 162 | } |
| 163 | else |
| 164 | { |
| 165 | BAD_TYPE: |
| 166 | search_error_message = string_sprintf("format error in lookup type \"%s\"", |
| 167 | name); |
| 168 | return -1; |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | /* Now we are left with a lookup name, possibly followed by * or *@, |
| 173 | and then by options starting with a "," */ |
| 174 | |
| 175 | len = Ustrlen(ss); |
| 176 | if ((t = Ustrchr(ss, '*'))) |
| 177 | { |
| 178 | len = t - ss; |
| 179 | *starflags |= (t[1] == '@' ? SEARCH_STARAT : SEARCH_STAR); |
| 180 | } |
| 181 | else |
| 182 | t = ss; |
| 183 | |
| 184 | if ((t = Ustrchr(t, ','))) |
| 185 | { |
| 186 | int l = t - ss; |
| 187 | if (l < len) len = l; |
| 188 | *opts = string_copy(t+1); |
| 189 | } |
| 190 | else |
| 191 | * opts = NULL; |
| 192 | |
| 193 | /* Check for the individual search type. Only those that are actually in the |
| 194 | binary are valid. For query-style types, "partial" and default types are |
| 195 | erroneous. */ |
| 196 | |
| 197 | stype = search_findtype(ss, len); |
| 198 | if (stype >= 0 && mac_islookup(stype, lookup_querystyle)) |
| 199 | { |
| 200 | if (pv >= 0) |
| 201 | { |
| 202 | search_error_message = string_sprintf("\"partial\" is not permitted " |
| 203 | "for lookup type \"%s\"", ss); |
| 204 | return -1; |
| 205 | } |
| 206 | if ((*starflags & (SEARCH_STAR|SEARCH_STARAT)) != 0) |
| 207 | { |
| 208 | search_error_message = string_sprintf("defaults using \"*\" or \"*@\" are " |
| 209 | "not permitted for lookup type \"%s\"", ss); |
| 210 | return -1; |
| 211 | } |
| 212 | } |
| 213 | |
| 214 | *ptypeptr = pv; |
| 215 | return stype; |
| 216 | } |
| 217 | |
| 218 | |
| 219 | |
| 220 | /************************************************* |
| 221 | * Release cached resources * |
| 222 | *************************************************/ |
| 223 | |
| 224 | /* When search_open is called it caches the "file" that it opens in |
| 225 | search_tree. The name of the tree node is a concatenation of the search type |
| 226 | with the file name. For query-style lookups, the file name is empty. Real files |
| 227 | are normally closed only when this tidyup routine is called, typically at the |
| 228 | end of sections of code where a number of lookups might occur. However, if too |
| 229 | many files are open simultaneously, some get closed beforehand. They can't be |
| 230 | removed from the tree. There is also a general tidyup function which is called |
| 231 | for the lookup driver, if it exists. |
| 232 | |
| 233 | First, there is an internal, recursive subroutine. |
| 234 | |
| 235 | Argument: a pointer to a search_openfile tree node |
| 236 | Returns: nothing |
| 237 | */ |
| 238 | |
| 239 | static void |
| 240 | tidyup_subtree(tree_node *t) |
| 241 | { |
| 242 | search_cache *c = (search_cache *)(t->data.ptr); |
| 243 | if (t->left != NULL) tidyup_subtree(t->left); |
| 244 | if (t->right != NULL) tidyup_subtree(t->right); |
| 245 | if (c != NULL && |
| 246 | c->handle != NULL && |
| 247 | lookup_list[c->search_type]->close != NULL) |
| 248 | lookup_list[c->search_type]->close(c->handle); |
| 249 | } |
| 250 | |
| 251 | |
| 252 | /* The external entry point |
| 253 | |
| 254 | Argument: none |
| 255 | Returns: nothing |
| 256 | */ |
| 257 | |
| 258 | void |
| 259 | search_tidyup(void) |
| 260 | { |
| 261 | int old_pool = store_pool; |
| 262 | |
| 263 | DEBUG(D_lookup) debug_printf_indent("search_tidyup called\n"); |
| 264 | |
| 265 | /* Close individually each cached open file. */ |
| 266 | |
| 267 | store_pool = POOL_SEARCH; |
| 268 | if (search_tree) |
| 269 | { |
| 270 | tidyup_subtree(search_tree); |
| 271 | search_tree = NULL; |
| 272 | } |
| 273 | open_top = open_bot = NULL; |
| 274 | open_filecount = 0; |
| 275 | |
| 276 | /* Call the general tidyup entry for any drivers that have one. */ |
| 277 | |
| 278 | for (int i = 0; i < lookup_list_count; i++) if (lookup_list[i]->tidy) |
| 279 | (lookup_list[i]->tidy)(); |
| 280 | |
| 281 | if (search_reset_point) search_reset_point = store_reset(search_reset_point); |
| 282 | store_pool = old_pool; |
| 283 | } |
| 284 | |
| 285 | |
| 286 | |
| 287 | |
| 288 | /************************************************* |
| 289 | * Open search database * |
| 290 | *************************************************/ |
| 291 | |
| 292 | /* A mode, and lists of owners and groups, are passed over for checking in |
| 293 | the cases where the database is one or more files. Return NULL, with a message |
| 294 | pointed to by message, in cases of error. |
| 295 | |
| 296 | For search types that use a file or files, check up on the mode after |
| 297 | opening. It is tempting to do a stat before opening the file, and use it as |
| 298 | an existence check. However, doing that opens a small security loophole in |
| 299 | that the status could be changed before the file is opened. Can't quite see |
| 300 | what problems this might lead to, but you can't be too careful where security |
| 301 | is concerned. Fstat() on an open file can normally be expected to succeed, |
| 302 | but there are some NFS states where it does not. |
| 303 | |
| 304 | There are two styles of query: (1) in the "single-key+file" style, a single |
| 305 | key string and a file name are given, for example, for linear searches, DBM |
| 306 | files, or for NIS. (2) In the "query" style, no "filename" is given; instead |
| 307 | just a single query string is passed. This applies to multiple-key lookup |
| 308 | types such as NIS+. |
| 309 | |
| 310 | Before opening, scan the tree of cached files to see if this file is already |
| 311 | open for the correct search type. If so, return the saved handle. If not, put |
| 312 | the handle in the tree for possible subsequent use. See search_tidyup above for |
| 313 | closing all the cached files. |
| 314 | |
| 315 | A count of open databases which use real files is maintained, and if this |
| 316 | gets too large, we have to close a cached file. Its entry remains in the tree, |
| 317 | but is marked closed. |
| 318 | |
| 319 | Arguments: |
| 320 | filename the name of the file for single-key+file style lookups, |
| 321 | NULL for query-style lookups |
| 322 | search_type the type of search required |
| 323 | modemask if a real single file is used, this specifies mode bits that |
| 324 | must not be set; otherwise it is ignored |
| 325 | owners if a real single file is used, this specifies the possible |
| 326 | owners of the file; otherwise it is ignored |
| 327 | owngroups if a real single file is used, this specifies the possible |
| 328 | group owners of the file; otherwise it is ignored |
| 329 | |
| 330 | Returns: an identifying handle for the open database; |
| 331 | this is the pointer to the tree block in the |
| 332 | cache of open files; return NULL on open failure, with |
| 333 | a message in search_error_message |
| 334 | */ |
| 335 | |
| 336 | void * |
| 337 | search_open(const uschar * filename, int search_type, int modemask, |
| 338 | uid_t * owners, gid_t * owngroups) |
| 339 | { |
| 340 | void *handle; |
| 341 | tree_node *t; |
| 342 | search_cache *c; |
| 343 | lookup_info *lk = lookup_list[search_type]; |
| 344 | uschar keybuffer[256]; |
| 345 | int old_pool = store_pool; |
| 346 | |
| 347 | if (filename && is_tainted(filename)) |
| 348 | { |
| 349 | log_write(0, LOG_MAIN|LOG_PANIC, |
| 350 | "Tainted filename for search: '%s'", filename); |
| 351 | return NULL; |
| 352 | } |
| 353 | |
| 354 | /* Change to the search store pool and remember our reset point */ |
| 355 | |
| 356 | store_pool = POOL_SEARCH; |
| 357 | if (!search_reset_point) search_reset_point = store_mark(); |
| 358 | |
| 359 | DEBUG(D_lookup) debug_printf_indent("search_open: %s \"%s\"\n", lk->name, |
| 360 | filename ? filename : US"NULL"); |
| 361 | |
| 362 | /* See if we already have this open for this type of search, and if so, |
| 363 | pass back the tree block as the handle. The key for the tree node is the search |
| 364 | type plus '0' concatenated with the file name. There may be entries in the tree |
| 365 | with closed files if a lot of files have been opened. */ |
| 366 | |
| 367 | sprintf(CS keybuffer, "%c%.254s", search_type + '0', |
| 368 | filename ? filename : US""); |
| 369 | |
| 370 | if ((t = tree_search(search_tree, keybuffer))) |
| 371 | { |
| 372 | if ((c = (search_cache *)t->data.ptr)->handle) |
| 373 | { |
| 374 | DEBUG(D_lookup) debug_printf_indent(" cached open\n"); |
| 375 | store_pool = old_pool; |
| 376 | return t; |
| 377 | } |
| 378 | DEBUG(D_lookup) debug_printf_indent(" cached closed\n"); |
| 379 | } |
| 380 | |
| 381 | /* Otherwise, we need to open the file or database - each search type has its |
| 382 | own code, which is now split off into separately compiled modules. Before doing |
| 383 | this, if the search type is one that uses real files, check on the number that |
| 384 | we are holding open in the cache. If the limit is reached, close the least |
| 385 | recently used one. */ |
| 386 | |
| 387 | if (lk->type == lookup_absfile && open_filecount >= lookup_open_max) |
| 388 | if (!open_bot) |
| 389 | log_write(0, LOG_MAIN|LOG_PANIC, "too many lookups open, but can't find " |
| 390 | "one to close"); |
| 391 | else |
| 392 | { |
| 393 | search_cache *c = (search_cache *)(open_bot->data.ptr); |
| 394 | DEBUG(D_lookup) debug_printf_indent("Too many lookup files open\n closing %s\n", |
| 395 | open_bot->name); |
| 396 | if ((open_bot = c->up)) |
| 397 | ((search_cache *)(open_bot->data.ptr))->down = NULL; |
| 398 | else |
| 399 | open_top = NULL; |
| 400 | ((lookup_list[c->search_type])->close)(c->handle); |
| 401 | c->handle = NULL; |
| 402 | open_filecount--; |
| 403 | } |
| 404 | |
| 405 | /* If opening is successful, call the file-checking function if there is one, |
| 406 | and if all is still well, enter the open database into the tree. */ |
| 407 | |
| 408 | if (!(handle = (lk->open)(filename, &search_error_message))) |
| 409 | { |
| 410 | store_pool = old_pool; |
| 411 | return NULL; |
| 412 | } |
| 413 | |
| 414 | if ( lk->check |
| 415 | && !lk->check(handle, filename, modemask, owners, owngroups, |
| 416 | &search_error_message)) |
| 417 | { |
| 418 | lk->close(handle); |
| 419 | store_pool = old_pool; |
| 420 | return NULL; |
| 421 | } |
| 422 | |
| 423 | /* If this is a search type that uses real files, keep count. */ |
| 424 | |
| 425 | if (lk->type == lookup_absfile) open_filecount++; |
| 426 | |
| 427 | /* If we found a previously opened entry in the tree, re-use it; otherwise |
| 428 | insert a new entry. On re-use, leave any cached lookup data and the lookup |
| 429 | count alone. */ |
| 430 | |
| 431 | if (!t) |
| 432 | { |
| 433 | t = store_get(sizeof(tree_node) + Ustrlen(keybuffer), FALSE); |
| 434 | t->data.ptr = c = store_get(sizeof(search_cache), FALSE); |
| 435 | c->item_cache = NULL; |
| 436 | Ustrcpy(t->name, keybuffer); |
| 437 | tree_insertnode(&search_tree, t); |
| 438 | } |
| 439 | else c = t->data.ptr; |
| 440 | |
| 441 | c->handle = handle; |
| 442 | c->search_type = search_type; |
| 443 | c->up = c->down = NULL; |
| 444 | |
| 445 | store_pool = old_pool; |
| 446 | return t; |
| 447 | } |
| 448 | |
| 449 | |
| 450 | |
| 451 | |
| 452 | |
| 453 | /************************************************* |
| 454 | * Internal function: Find one item in database * |
| 455 | *************************************************/ |
| 456 | |
| 457 | /* The answer is always put into dynamic store. The last lookup for each handle |
| 458 | is cached. |
| 459 | |
| 460 | Arguments: |
| 461 | handle the handle from search_open; points to tree node |
| 462 | filename the filename that was handed to search_open, or |
| 463 | NULL for query-style searches |
| 464 | keystring the keystring for single-key+file lookups, or |
| 465 | the querystring for query-style lookups |
| 466 | opts type-specific options |
| 467 | |
| 468 | Returns: a pointer to a dynamic string containing the answer, |
| 469 | or NULL if the query failed or was deferred; in the |
| 470 | latter case, search_find_defer is set TRUE; after an unusual |
| 471 | failure, there may be a message in search_error_message. |
| 472 | */ |
| 473 | |
| 474 | static uschar * |
| 475 | internal_search_find(void * handle, const uschar * filename, uschar * keystring, |
| 476 | const uschar * opts) |
| 477 | { |
| 478 | tree_node * t = (tree_node *)handle; |
| 479 | search_cache * c = (search_cache *)(t->data.ptr); |
| 480 | expiring_data * e = NULL; /* compiler quietening */ |
| 481 | uschar * data = NULL; |
| 482 | int search_type = t->name[0] - '0'; |
| 483 | int old_pool = store_pool; |
| 484 | |
| 485 | /* Lookups that return DEFER may not always set an error message. So that |
| 486 | the callers don't have to test for NULL, set an empty string. */ |
| 487 | |
| 488 | search_error_message = US""; |
| 489 | f.search_find_defer = FALSE; |
| 490 | |
| 491 | DEBUG(D_lookup) debug_printf_indent("internal_search_find: file=\"%s\"\n " |
| 492 | "type=%s key=\"%s\" opts=%s%s%s\n", filename, |
| 493 | lookup_list[search_type]->name, keystring, |
| 494 | opts ? "\"" : "", opts, opts ? "\"" : ""); |
| 495 | |
| 496 | /* Insurance. If the keystring is empty, just fail. */ |
| 497 | |
| 498 | if (keystring[0] == 0) return NULL; |
| 499 | |
| 500 | /* Use the special store pool for search data */ |
| 501 | |
| 502 | store_pool = POOL_SEARCH; |
| 503 | |
| 504 | /* Look up the data for the key, unless it is already in the cache for this |
| 505 | file. No need to check c->item_cache for NULL, tree_search will do so. */ |
| 506 | |
| 507 | if ( (t = tree_search(c->item_cache, keystring)) |
| 508 | && (!(e = t->data.ptr)->expiry || e->expiry > time(NULL)) |
| 509 | && (!opts && !e->opts || opts && e->opts && Ustrcmp(opts, e->opts) == 0) |
| 510 | ) |
| 511 | { /* Data was in the cache already; set the pointer from the tree node */ |
| 512 | data = e->data.ptr; |
| 513 | DEBUG(D_lookup) debug_printf_indent("cached data used for lookup of %s%s%s\n", |
| 514 | keystring, |
| 515 | filename ? US"\n in " : US"", filename ? filename : US""); |
| 516 | } |
| 517 | else |
| 518 | { |
| 519 | uint do_cache = UINT_MAX; |
| 520 | int keylength = Ustrlen(keystring); |
| 521 | |
| 522 | DEBUG(D_lookup) |
| 523 | { |
| 524 | if (t) |
| 525 | debug_printf_indent("cached data found but either wrong opts or dated; "); |
| 526 | debug_printf_indent("%s lookup required for %s%s%s\n", |
| 527 | filename ? US"file" : US"database", |
| 528 | keystring, |
| 529 | filename ? US"\n in " : US"", filename ? filename : US""); |
| 530 | } |
| 531 | |
| 532 | /* Call the code for the different kinds of search. DEFER is handled |
| 533 | like FAIL, except that search_find_defer is set so the caller can |
| 534 | distinguish if necessary. */ |
| 535 | |
| 536 | if (lookup_list[search_type]->find(c->handle, filename, keystring, keylength, |
| 537 | &data, &search_error_message, &do_cache, opts) == DEFER) |
| 538 | f.search_find_defer = TRUE; |
| 539 | |
| 540 | /* A record that has been found is now in data, which is either NULL |
| 541 | or points to a bit of dynamic store. Cache the result of the lookup if |
| 542 | caching is permitted. Lookups can disable caching, when they did something |
| 543 | that changes their data. The mysql and pgsql lookups do this when an |
| 544 | UPDATE/INSERT query was executed. */ |
| 545 | |
| 546 | else if (do_cache) |
| 547 | { |
| 548 | int len = keylength + 1; |
| 549 | |
| 550 | if (t) /* Previous, out-of-date cache entry. Update with the */ |
| 551 | { /* new result and forget the old one */ |
| 552 | e->expiry = do_cache == UINT_MAX ? 0 : time(NULL)+do_cache; |
| 553 | e->opts = opts; |
| 554 | e->data.ptr = data; |
| 555 | } |
| 556 | else |
| 557 | { |
| 558 | e = store_get(sizeof(expiring_data) + sizeof(tree_node) + len, is_tainted(keystring)); |
| 559 | e->expiry = do_cache == UINT_MAX ? 0 : time(NULL)+do_cache; |
| 560 | e->opts = opts; |
| 561 | e->data.ptr = data; |
| 562 | t = (tree_node *)(e+1); |
| 563 | memcpy(t->name, keystring, len); |
| 564 | t->data.ptr = e; |
| 565 | tree_insertnode(&c->item_cache, t); |
| 566 | } |
| 567 | } |
| 568 | |
| 569 | /* If caching was disabled, empty the cache tree. We just set the cache |
| 570 | pointer to NULL here, because we cannot release the store at this stage. */ |
| 571 | |
| 572 | else |
| 573 | { |
| 574 | DEBUG(D_lookup) debug_printf_indent("lookup forced cache cleanup\n"); |
| 575 | c->item_cache = NULL; |
| 576 | } |
| 577 | } |
| 578 | |
| 579 | DEBUG(D_lookup) |
| 580 | { |
| 581 | if (data) |
| 582 | debug_printf_indent("lookup yielded: %s\n", data); |
| 583 | else if (f.search_find_defer) |
| 584 | debug_printf_indent("lookup deferred: %s\n", search_error_message); |
| 585 | else debug_printf_indent("lookup failed\n"); |
| 586 | } |
| 587 | |
| 588 | /* Return it in new dynamic store in the regular pool */ |
| 589 | |
| 590 | store_pool = old_pool; |
| 591 | return data ? string_copy(data) : NULL; |
| 592 | } |
| 593 | |
| 594 | |
| 595 | |
| 596 | |
| 597 | /************************************************* |
| 598 | * Find one item in database, possibly wildcarded * |
| 599 | *************************************************/ |
| 600 | |
| 601 | /* This function calls the internal function above; once only if there |
| 602 | is no partial matching, but repeatedly when partial matching is requested. |
| 603 | |
| 604 | Arguments: |
| 605 | handle the handle from search_open |
| 606 | filename the filename that was handed to search_open, or |
| 607 | NULL for query-style searches |
| 608 | keystring the keystring for single-key+file lookups, or |
| 609 | the querystring for query-style lookups |
| 610 | partial -1 means no partial matching; |
| 611 | otherwise it's the minimum number of components; |
| 612 | affix the affix string for partial matching |
| 613 | affixlen the length of the affix string |
| 614 | starflags SEARCH_STAR and SEARCH_STARAT flags |
| 615 | expand_setup pointer to offset for setting up expansion strings; |
| 616 | don't do any if < 0 |
| 617 | opts type-specific options |
| 618 | |
| 619 | Returns: a pointer to a dynamic string containing the answer, |
| 620 | or NULL if the query failed or was deferred; in the |
| 621 | latter case, search_find_defer is set TRUE |
| 622 | */ |
| 623 | |
| 624 | uschar * |
| 625 | search_find(void * handle, const uschar * filename, uschar * keystring, |
| 626 | int partial, const uschar * affix, int affixlen, int starflags, |
| 627 | int * expand_setup, const uschar * opts) |
| 628 | { |
| 629 | tree_node *t = (tree_node *)handle; |
| 630 | BOOL set_null_wild = FALSE; |
| 631 | uschar *yield; |
| 632 | |
| 633 | DEBUG(D_lookup) |
| 634 | { |
| 635 | if (partial < 0) affixlen = 99; /* So that "NULL" prints */ |
| 636 | debug_printf_indent("search_find: file=\"%s\"\n key=\"%s\" " |
| 637 | "partial=%d affix=%.*s starflags=%x opts=%s%s%s\n", |
| 638 | filename ? filename : US"NULL", |
| 639 | keystring, partial, affixlen, affix, starflags, |
| 640 | opts ? "\"" : "", opts, opts ? "\"" : ""); |
| 641 | |
| 642 | } |
| 643 | |
| 644 | /* Arrange to put this database at the top of the LRU chain if it is a type |
| 645 | that opens real files. */ |
| 646 | |
| 647 | if ( open_top != (tree_node *)handle |
| 648 | && lookup_list[t->name[0]-'0']->type == lookup_absfile) |
| 649 | { |
| 650 | search_cache *c = (search_cache *)(t->data.ptr); |
| 651 | tree_node *up = c->up; |
| 652 | tree_node *down = c->down; |
| 653 | |
| 654 | /* Cut it out of the list. A newly opened file will a NULL up pointer. |
| 655 | Otherwise there will be a non-NULL up pointer, since we checked above that |
| 656 | this block isn't already at the top of the list. */ |
| 657 | |
| 658 | if (up) |
| 659 | { |
| 660 | ((search_cache *)(up->data.ptr))->down = down; |
| 661 | if (down) |
| 662 | ((search_cache *)(down->data.ptr))->up = up; |
| 663 | else |
| 664 | open_bot = up; |
| 665 | } |
| 666 | |
| 667 | /* Now put it at the head of the list. */ |
| 668 | |
| 669 | c->up = NULL; |
| 670 | c->down = open_top; |
| 671 | if (!open_top) open_bot = t; |
| 672 | else ((search_cache *)(open_top->data.ptr))->up = t; |
| 673 | open_top = t; |
| 674 | } |
| 675 | |
| 676 | DEBUG(D_lookup) |
| 677 | { |
| 678 | debug_printf_indent("LRU list:\n"); |
| 679 | for (tree_node *t = open_top; t; ) |
| 680 | { |
| 681 | search_cache *c = (search_cache *)(t->data.ptr); |
| 682 | debug_printf_indent(" %s\n", t->name); |
| 683 | if (t == open_bot) debug_printf_indent(" End\n"); |
| 684 | t = c->down; |
| 685 | } |
| 686 | } |
| 687 | |
| 688 | /* First of all, try to match the key string verbatim. If matched a complete |
| 689 | entry but could have been partial, flag to set up variables. */ |
| 690 | |
| 691 | yield = internal_search_find(handle, filename, keystring, opts); |
| 692 | if (f.search_find_defer) return NULL; |
| 693 | |
| 694 | if (yield) { if (partial >= 0) set_null_wild = TRUE; } |
| 695 | |
| 696 | /* Not matched a complete entry; handle partial lookups, but only if the full |
| 697 | search didn't defer. Don't use string_sprintf() to construct the initial key, |
| 698 | just in case the original key is too long for the string_sprintf() buffer (it |
| 699 | *has* happened!). The case of a zero-length affix has to be treated specially. |
| 700 | */ |
| 701 | |
| 702 | else if (partial >= 0) |
| 703 | { |
| 704 | int len = Ustrlen(keystring); |
| 705 | uschar *keystring2; |
| 706 | |
| 707 | /* Try with the affix on the front, except for a zero-length affix */ |
| 708 | |
| 709 | if (affixlen == 0) keystring2 = keystring; else |
| 710 | { |
| 711 | keystring2 = store_get(len + affixlen + 1, |
| 712 | is_tainted(keystring) || is_tainted(affix)); |
| 713 | Ustrncpy(keystring2, affix, affixlen); |
| 714 | Ustrcpy(keystring2 + affixlen, keystring); |
| 715 | DEBUG(D_lookup) debug_printf_indent("trying partial match %s\n", keystring2); |
| 716 | yield = internal_search_find(handle, filename, keystring2, opts); |
| 717 | if (f.search_find_defer) return NULL; |
| 718 | } |
| 719 | |
| 720 | /* The key in its entirety did not match a wild entry; try chopping off |
| 721 | leading components. */ |
| 722 | |
| 723 | if (yield == NULL) |
| 724 | { |
| 725 | int dotcount = 0; |
| 726 | uschar *keystring3 = keystring2 + affixlen; |
| 727 | uschar *s = keystring3; |
| 728 | while (*s != 0) if (*s++ == '.') dotcount++; |
| 729 | |
| 730 | while (dotcount-- >= partial) |
| 731 | { |
| 732 | while (*keystring3 != 0 && *keystring3 != '.') keystring3++; |
| 733 | |
| 734 | /* If we get right to the end of the string (which will be the last time |
| 735 | through this loop), we've failed if the affix is null. Otherwise do one |
| 736 | last lookup for the affix itself, but if it is longer than 1 character, |
| 737 | remove the last character if it is ".". */ |
| 738 | |
| 739 | if (*keystring3 == 0) |
| 740 | { |
| 741 | if (affixlen < 1) break; |
| 742 | if (affixlen > 1 && affix[affixlen-1] == '.') affixlen--; |
| 743 | Ustrncpy(keystring2, affix, affixlen); |
| 744 | keystring2[affixlen] = 0; |
| 745 | keystring3 = keystring2; |
| 746 | } |
| 747 | else |
| 748 | { |
| 749 | keystring3 -= affixlen - 1; |
| 750 | if (affixlen > 0) Ustrncpy(keystring3, affix, affixlen); |
| 751 | } |
| 752 | |
| 753 | DEBUG(D_lookup) debug_printf_indent("trying partial match %s\n", keystring3); |
| 754 | yield = internal_search_find(handle, filename, keystring3, opts); |
| 755 | if (f.search_find_defer) return NULL; |
| 756 | if (yield) |
| 757 | { |
| 758 | /* First variable is the wild part; second is the fixed part. Take care |
| 759 | to get it right when keystring3 is just "*". */ |
| 760 | |
| 761 | if (expand_setup && *expand_setup >= 0) |
| 762 | { |
| 763 | int fixedlength = Ustrlen(keystring3) - affixlen; |
| 764 | int wildlength = Ustrlen(keystring) - fixedlength - 1; |
| 765 | *expand_setup += 1; |
| 766 | expand_nstring[*expand_setup] = keystring; |
| 767 | expand_nlength[*expand_setup] = wildlength; |
| 768 | *expand_setup += 1; |
| 769 | expand_nstring[*expand_setup] = keystring + wildlength + 1; |
| 770 | expand_nlength[*expand_setup] = (fixedlength < 0)? 0 : fixedlength; |
| 771 | } |
| 772 | break; |
| 773 | } |
| 774 | keystring3 += affixlen; |
| 775 | } |
| 776 | } |
| 777 | |
| 778 | else set_null_wild = TRUE; /* Matched a wild entry without any wild part */ |
| 779 | } |
| 780 | |
| 781 | /* If nothing has been matched, but the option to look for "*@" is set, try |
| 782 | replacing everything to the left of @ by *. After a match, the wild part |
| 783 | is set to the string to the left of the @. */ |
| 784 | |
| 785 | if (!yield && starflags & SEARCH_STARAT) |
| 786 | { |
| 787 | uschar *atat = Ustrrchr(keystring, '@'); |
| 788 | if (atat != NULL && atat > keystring) |
| 789 | { |
| 790 | int savechar; |
| 791 | savechar = *(--atat); |
| 792 | *atat = '*'; |
| 793 | |
| 794 | DEBUG(D_lookup) debug_printf_indent("trying default match %s\n", atat); |
| 795 | yield = internal_search_find(handle, filename, atat, opts); |
| 796 | *atat = savechar; |
| 797 | if (f.search_find_defer) return NULL; |
| 798 | |
| 799 | if (yield && expand_setup && *expand_setup >= 0) |
| 800 | { |
| 801 | *expand_setup += 1; |
| 802 | expand_nstring[*expand_setup] = keystring; |
| 803 | expand_nlength[*expand_setup] = atat - keystring + 1; |
| 804 | *expand_setup += 1; |
| 805 | expand_nstring[*expand_setup] = keystring; |
| 806 | expand_nlength[*expand_setup] = 0; |
| 807 | } |
| 808 | } |
| 809 | } |
| 810 | |
| 811 | /* If we still haven't matched anything, and the option to look for "*" is set, |
| 812 | try that. If we do match, the first variable (the wild part) is the whole key, |
| 813 | and the second is empty. */ |
| 814 | |
| 815 | if (!yield && starflags & (SEARCH_STAR|SEARCH_STARAT)) |
| 816 | { |
| 817 | DEBUG(D_lookup) debug_printf_indent("trying to match *\n"); |
| 818 | yield = internal_search_find(handle, filename, US"*", opts); |
| 819 | if (yield && expand_setup && *expand_setup >= 0) |
| 820 | { |
| 821 | *expand_setup += 1; |
| 822 | expand_nstring[*expand_setup] = keystring; |
| 823 | expand_nlength[*expand_setup] = Ustrlen(keystring); |
| 824 | *expand_setup += 1; |
| 825 | expand_nstring[*expand_setup] = keystring; |
| 826 | expand_nlength[*expand_setup] = 0; |
| 827 | } |
| 828 | } |
| 829 | |
| 830 | /* If this was a potentially partial lookup, and we matched either a |
| 831 | complete non-wild domain entry, or we matched a wild-carded entry without |
| 832 | chopping off any of the domain components, set up the expansion variables |
| 833 | (if required) so that the first one is empty, and the second one is the |
| 834 | fixed part of the domain. The set_null_wild flag is set only when yield is not |
| 835 | NULL. */ |
| 836 | |
| 837 | if (set_null_wild && expand_setup && *expand_setup >= 0) |
| 838 | { |
| 839 | *expand_setup += 1; |
| 840 | expand_nstring[*expand_setup] = keystring; |
| 841 | expand_nlength[*expand_setup] = 0; |
| 842 | *expand_setup += 1; |
| 843 | expand_nstring[*expand_setup] = keystring; |
| 844 | expand_nlength[*expand_setup] = Ustrlen(keystring); |
| 845 | } |
| 846 | |
| 847 | return yield; |
| 848 | } |
| 849 | |
| 850 | /* End of search.c */ |