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c988f1f4 | 1 | /* $Cambridge: exim/src/src/search.c,v 1.2 2005/01/04 10:00:42 ph10 Exp $ */ |
059ec3d9 PH |
2 | |
3 | /************************************************* | |
4 | * Exim - an Internet mail transport agent * | |
5 | *************************************************/ | |
6 | ||
c988f1f4 | 7 | /* Copyright (c) University of Cambridge 1995 - 2005 */ |
059ec3d9 PH |
8 | /* See the file NOTICE for conditions of use and distribution. */ |
9 | ||
10 | /* A set of functions to search databases in various formats. An open | |
11 | database is represented by a void * value which is returned from a lookup- | |
12 | specific "open" function. These are now all held in individual modules in the | |
13 | lookups subdirectory and the functions here form a generic interface. | |
14 | ||
15 | Caching is used to improve performance. Open files are cached until a tidyup | |
16 | function is called, and for each file the result of the last lookup is cached. | |
17 | However, if too many files are opened, some of those that are not in use have | |
18 | to be closed. Those open items that use real files are kept on a LRU chain to | |
19 | help with this. | |
20 | ||
21 | All the data is held in permanent store so as to be independent of the stacking | |
22 | pool that is reset from time to time. In fact, we use malloc'd store so that it | |
23 | can be freed when the caches are tidied up. It isn't actually clear whether | |
24 | this is a benefit or not, to be honest. */ | |
25 | ||
26 | #include "exim.h" | |
27 | ||
28 | ||
29 | /* Tree in which to cache open files until tidyup called. */ | |
30 | ||
31 | static tree_node *search_tree = NULL; | |
32 | ||
33 | /* Two-way chain of open databases that use real files. This is maintained in | |
34 | recently-used order for the purposes of closing the least recently used when | |
35 | too many files are open. */ | |
36 | ||
37 | static tree_node *open_top = NULL; | |
38 | static tree_node *open_bot = NULL; | |
39 | ||
40 | /* Count of open databases that use real files */ | |
41 | ||
42 | static int open_filecount = 0; | |
43 | ||
44 | /* Allow us to reset store used for lookups and lookup caching */ | |
45 | ||
46 | static void *search_reset_point = NULL; | |
47 | ||
48 | ||
49 | ||
50 | /************************************************* | |
51 | * Validate a plain lookup type name * | |
52 | *************************************************/ | |
53 | ||
54 | /* Only those names that are recognized and whose code is included in the | |
55 | binary give an OK response. Use a binary chop search now that the list has got | |
56 | so long. | |
57 | ||
58 | Arguments: | |
59 | name lookup type name - not necessarily zero terminated (e.g. dbm*) | |
60 | len length of the name | |
61 | ||
62 | Returns: +ve => valid lookup name; value is offset in lookup_list | |
63 | -ve => invalid name; message in search_error_message. | |
64 | */ | |
65 | ||
66 | int | |
67 | search_findtype(uschar *name, int len) | |
68 | { | |
69 | int bot = 0; | |
70 | int top = lookup_list_count; | |
71 | while (top > bot) | |
72 | { | |
73 | int mid = (top + bot)/2; | |
74 | int c = Ustrncmp(name, lookup_list[mid].name, len); | |
75 | ||
76 | /* If c == 0 we have matched the incoming name with the start of the search | |
77 | type name. However, some search types are substrings of others (e.g. nis and | |
78 | nisplus) so we need to check that the lengths are the same. The length of the | |
79 | type name cannot be shorter (else c would not be 0); if it is not equal it | |
80 | must be longer, and in that case, the incoming name comes before the name we | |
81 | are testing. By leaving c == 0 when the lengths are different, and doing a | |
82 | > 0 test below, this all falls out correctly. */ | |
83 | ||
84 | if (c == 0 && Ustrlen(lookup_list[mid].name) == len) | |
85 | { | |
86 | if (lookup_list[mid].find != NULL) return mid; | |
87 | search_error_message = string_sprintf("lookup type \"%.*s\" is not " | |
88 | "available (not in the binary - check buildtime LOOKUP configuration)", | |
89 | len, name); | |
90 | return -1; | |
91 | } | |
92 | ||
93 | if (c > 0) bot = mid + 1; else top = mid; | |
94 | } | |
95 | ||
96 | search_error_message = string_sprintf("unknown lookup type \"%.*s\"",len,name); | |
97 | return -1; | |
98 | } | |
99 | ||
100 | ||
101 | ||
102 | /************************************************* | |
103 | * Validate a full lookup type name * | |
104 | *************************************************/ | |
105 | ||
106 | /* This function recognizes the "partial-" prefix and also terminating * and *@ | |
107 | suffixes. | |
108 | ||
109 | Arguments: | |
110 | name the full lookup type name | |
111 | ptypeptr where to put the partial type | |
112 | after subtraction of 1024 or 2048: | |
113 | negative => no partial matching | |
114 | non-negative => minimum number of non-wild components | |
115 | ptypeaff where to put a pointer to the affix | |
116 | the affix is within name if supplied therein | |
117 | otherwise it's a literal string | |
118 | afflen the length of the affix | |
119 | starflags where to put the SEARCH_STAR and SEARCH_STARAT flags | |
120 | ||
121 | Returns: +ve => valid lookup name; value is offset in lookup_list | |
122 | -ve => invalid name; message in search_error_message. | |
123 | */ | |
124 | ||
125 | int | |
126 | search_findtype_partial(uschar *name, int *ptypeptr, uschar **ptypeaff, | |
127 | int *afflen, int *starflags) | |
128 | { | |
129 | int len, stype; | |
130 | int pv = -1; | |
131 | uschar *ss = name; | |
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 | ||
174 | len = Ustrlen(ss); | |
175 | if (len >= 2 && Ustrncmp(ss + len - 2, "*@", 2) == 0) | |
176 | { | |
177 | *starflags |= SEARCH_STARAT; | |
178 | len -= 2; | |
179 | } | |
180 | else if (len >= 1 && ss[len-1] == '*') | |
181 | { | |
182 | *starflags |= SEARCH_STAR; | |
183 | len--; | |
184 | } | |
185 | ||
186 | /* Check for the individual search type. Only those that are actually in the | |
187 | binary are valid. For query-style types, "partial" is an error. */ | |
188 | ||
189 | stype = search_findtype(ss, len); | |
190 | if (pv >= 0 && mac_islookup(stype, lookup_querystyle)) | |
191 | { | |
192 | search_error_message = string_sprintf("\"partial\" is not permitted " | |
193 | "for lookup type \"%s\"", ss); | |
194 | return -1; | |
195 | } | |
196 | ||
197 | /* All is well; pass back the partial type and return the lookup type. */ | |
198 | ||
199 | *ptypeptr = pv; | |
200 | return stype; | |
201 | } | |
202 | ||
203 | ||
204 | ||
205 | /************************************************* | |
206 | * Release cached resources * | |
207 | *************************************************/ | |
208 | ||
209 | /* When search_open is called it caches the "file" that it opens in | |
210 | search_tree. The name of the tree node is a concatenation of the search type | |
211 | with the file name. For query-style lookups, the file name is empty. Real files | |
212 | are normally closed only when this tidyup routine is called, typically at the | |
213 | end of sections of code where a number of lookups might occur. However, if too | |
214 | many files are open simultaneously, some get closed beforehand. They can't be | |
215 | removed from the tree. There is also a general tidyup function which is called | |
216 | for the lookup driver, if it exists. | |
217 | ||
218 | First, there is an internal, recursive subroutine. | |
219 | ||
220 | Argument: a pointer to a search_openfile tree node | |
221 | Returns: nothing | |
222 | */ | |
223 | ||
224 | static void | |
225 | tidyup_subtree(tree_node *t) | |
226 | { | |
227 | search_cache *c = (search_cache *)(t->data.ptr); | |
228 | if (t->left != NULL) tidyup_subtree(t->left); | |
229 | if (t->right != NULL) tidyup_subtree(t->right); | |
230 | if (c != NULL && | |
231 | c->handle != NULL && | |
232 | lookup_list[c->search_type].close != NULL) | |
233 | lookup_list[c->search_type].close(c->handle); | |
234 | } | |
235 | ||
236 | ||
237 | /* The external entry point | |
238 | ||
239 | Argument: none | |
240 | Returns: nothing | |
241 | */ | |
242 | ||
243 | void | |
244 | search_tidyup(void) | |
245 | { | |
246 | int i; | |
247 | int old_pool = store_pool; | |
248 | ||
249 | DEBUG(D_lookup) debug_printf("search_tidyup called\n"); | |
250 | ||
251 | /* Close individually each cached open file. */ | |
252 | ||
253 | store_pool = POOL_SEARCH; | |
254 | if (search_tree != NULL) | |
255 | { | |
256 | tidyup_subtree(search_tree); | |
257 | search_tree = NULL; | |
258 | } | |
259 | open_top = open_bot = NULL; | |
260 | open_filecount = 0; | |
261 | ||
262 | /* Call the general tidyup entry for any drivers that have one. */ | |
263 | ||
264 | for (i = 0; i < lookup_list_count; i++) | |
265 | if (lookup_list[i].tidy != NULL) (lookup_list[i].tidy)(); | |
266 | ||
267 | if (search_reset_point != NULL) store_reset(search_reset_point); | |
268 | search_reset_point = NULL; | |
269 | store_pool = old_pool; | |
270 | } | |
271 | ||
272 | ||
273 | ||
274 | ||
275 | /************************************************* | |
276 | * Open search database * | |
277 | *************************************************/ | |
278 | ||
279 | /* A mode, and lists of owners and groups, are passed over for checking in | |
280 | the cases where the database is one or more files. Return NULL, with a message | |
281 | pointed to by message, in cases of error. | |
282 | ||
283 | For search types that use a file or files, check up on the mode after | |
284 | opening. It is tempting to do a stat before opening the file, and use it as | |
285 | an existence check. However, doing that opens a small security loophole in | |
286 | that the status could be changed before the file is opened. Can't quite see | |
287 | what problems this might lead to, but you can't be too careful where security | |
288 | is concerned. Fstat() on an open file can normally be expected to succeed, | |
289 | but there are some NFS states where it does not. | |
290 | ||
291 | There are two styles of query: (1) in the "single-key+file" style, a single | |
292 | key string and a file name are given, for example, for linear searches, DBM | |
293 | files, or for NIS. (2) In the "query" style, no "filename" is given; instead | |
294 | just a single query string is passed. This applies to multiple-key lookup | |
295 | types such as NIS+. | |
296 | ||
297 | Before opening, scan the tree of cached files to see if this file is already | |
298 | open for the correct search type. If so, return the saved handle. If not, put | |
299 | the handle in the tree for possible subsequent use. See search_tidyup above for | |
300 | closing all the cached files. | |
301 | ||
302 | A count of open databases which use real files is maintained, and if this | |
303 | gets too large, we have to close a cached file. Its entry remains in the tree, | |
304 | but is marked closed. | |
305 | ||
306 | Arguments: | |
307 | filename the name of the file for single-key+file style lookups, | |
308 | NULL for query-style lookups | |
309 | search_type the type of search required | |
310 | modemask if a real single file is used, this specifies mode bits that | |
311 | must not be set; otherwise it is ignored | |
312 | owners if a real single file is used, this specifies the possible | |
313 | owners of the file; otherwise it is ignored | |
314 | owngroups if a real single file is used, this specifies the possible | |
315 | group owners of the file; otherwise it is ignored | |
316 | ||
317 | Returns: an identifying handle for the open database; | |
318 | this is the pointer to the tree block in the | |
319 | cache of open files; return NULL on open failure, with | |
320 | a message in search_error_message | |
321 | */ | |
322 | ||
323 | void * | |
324 | search_open(uschar *filename, int search_type, int modemask, uid_t *owners, | |
325 | gid_t *owngroups) | |
326 | { | |
327 | void *handle; | |
328 | tree_node *t; | |
329 | search_cache *c; | |
330 | lookup_info *lk = lookup_list + search_type; | |
331 | uschar keybuffer[256]; | |
332 | int old_pool = store_pool; | |
333 | ||
334 | /* Change to the search store pool and remember our reset point */ | |
335 | ||
336 | store_pool = POOL_SEARCH; | |
337 | if (search_reset_point == NULL) search_reset_point = store_get(0); | |
338 | ||
339 | DEBUG(D_lookup) debug_printf("search_open: %s \"%s\"\n", lk->name, | |
340 | (filename == NULL)? US"NULL" : filename); | |
341 | ||
342 | /* See if we already have this open for this type of search, and if so, | |
343 | pass back the tree block as the handle. The key for the tree node is the search | |
344 | type plus '0' concatenated with the file name. There may be entries in the tree | |
345 | with closed files if a lot of files have been opened. */ | |
346 | ||
347 | sprintf(CS keybuffer, "%c%.254s", search_type + '0', | |
348 | (filename == NULL)? US"" : filename); | |
349 | ||
350 | if ((t = tree_search(search_tree, keybuffer)) != NULL) | |
351 | { | |
352 | c = (search_cache *)(t->data.ptr); | |
353 | if (c->handle != NULL) | |
354 | { | |
355 | DEBUG(D_lookup) debug_printf(" cached open\n"); | |
356 | store_pool = old_pool; | |
357 | return t; | |
358 | } | |
359 | DEBUG(D_lookup) debug_printf(" cached closed\n"); | |
360 | } | |
361 | ||
362 | /* Otherwise, we need to open the file or database - each search type has its | |
363 | own code, which is now split off into separately compiled modules. Before doing | |
364 | this, if the search type is one that uses real files, check on the number that | |
365 | we are holding open in the cache. If the limit is reached, close the least | |
366 | recently used one. */ | |
367 | ||
368 | if (lk->type == lookup_absfile && open_filecount >= lookup_open_max) | |
369 | { | |
370 | if (open_bot == NULL) | |
371 | log_write(0, LOG_MAIN|LOG_PANIC, "too many lookups open, but can't find " | |
372 | "one to close"); | |
373 | else | |
374 | { | |
375 | search_cache *c = (search_cache *)(open_bot->data.ptr); | |
376 | DEBUG(D_lookup) debug_printf("Too many lookup files open\n closing %s\n", | |
377 | open_bot->name); | |
378 | open_bot = c->up; | |
379 | if (open_bot != NULL) | |
380 | ((search_cache *)(open_bot->data.ptr))->down = NULL; | |
381 | else | |
382 | open_top = NULL; | |
383 | ((lookup_list + c->search_type)->close)(c->handle); | |
384 | c->handle = NULL; | |
385 | open_filecount--; | |
386 | } | |
387 | } | |
388 | ||
389 | /* If opening is successful, call the file-checking function if there is one, | |
390 | and if all is still well, enter the open database into the tree. */ | |
391 | ||
392 | handle = lk->open(filename, &search_error_message); | |
393 | if (handle == NULL) | |
394 | { | |
395 | store_pool = old_pool; | |
396 | return NULL; | |
397 | } | |
398 | ||
399 | if (lk->check != NULL && | |
400 | !lk->check(handle, filename, modemask, owners, owngroups, | |
401 | &search_error_message)) | |
402 | { | |
403 | lk->close(handle); | |
404 | store_pool = old_pool; | |
405 | return NULL; | |
406 | } | |
407 | ||
408 | /* If this is a search type that uses real files, keep count. */ | |
409 | ||
410 | if (lk->type == lookup_absfile) open_filecount++; | |
411 | ||
412 | /* If we found a previously opened entry in the tree, re-use it; otherwise | |
413 | insert a new entry. On re-use, leave any cached lookup data and the lookup | |
414 | count alone. */ | |
415 | ||
416 | if (t == NULL) | |
417 | { | |
418 | t = store_get(sizeof(tree_node) + Ustrlen(keybuffer)); | |
419 | t->data.ptr = c = store_get(sizeof(search_cache)); | |
420 | c->item_cache = NULL; | |
421 | Ustrcpy(t->name, keybuffer); | |
422 | tree_insertnode(&search_tree, t); | |
423 | } | |
424 | else c = t->data.ptr; | |
425 | ||
426 | c->handle = handle; | |
427 | c->search_type = search_type; | |
428 | c->up = c->down = NULL; | |
429 | ||
430 | store_pool = old_pool; | |
431 | return t; | |
432 | } | |
433 | ||
434 | ||
435 | ||
436 | ||
437 | ||
438 | /************************************************* | |
439 | * Internal function: Find one item in database * | |
440 | *************************************************/ | |
441 | ||
442 | /* The answer is always put into dynamic store. The last lookup for each handle | |
443 | is cached. | |
444 | ||
445 | Arguments: | |
446 | handle the handle from search_open; points to tree node | |
447 | filename the filename that was handed to search_open, or | |
448 | NULL for query-style searches | |
449 | keystring the keystring for single-key+file lookups, or | |
450 | the querystring for query-style lookups | |
451 | ||
452 | Returns: a pointer to a dynamic string containing the answer, | |
453 | or NULL if the query failed or was deferred; in the | |
454 | latter case, search_find_defer is set TRUE; after an unusual | |
455 | failure, there may be a message in search_error_message. | |
456 | */ | |
457 | ||
458 | static uschar * | |
459 | internal_search_find(void *handle, uschar *filename, uschar *keystring) | |
460 | { | |
461 | tree_node *t = (tree_node *)handle; | |
462 | search_cache *c = (search_cache *)(t->data.ptr); | |
463 | uschar *data = NULL; | |
464 | int search_type = t->name[0] - '0'; | |
465 | int old_pool = store_pool; | |
466 | ||
467 | /* Lookups that return DEFER may not always set an error message. So that | |
468 | the callers don't have to test for NULL, set an empty string. */ | |
469 | ||
470 | search_error_message = US""; | |
471 | search_find_defer = FALSE; | |
472 | ||
473 | DEBUG(D_lookup) debug_printf("internal_search_find: file=\"%s\"\n " | |
474 | "type=%s key=\"%s\"\n", filename, | |
475 | lookup_list[search_type].name, keystring); | |
476 | ||
477 | /* Insurance. If the keystring is empty, just fail. */ | |
478 | ||
479 | if (keystring[0] == 0) return NULL; | |
480 | ||
481 | /* Use the special store pool for search data */ | |
482 | ||
483 | store_pool = POOL_SEARCH; | |
484 | ||
485 | /* Look up the data for the key, unless it is already in the cache for this | |
486 | file. No need to check c->item_cache for NULL, tree_search will do so. */ | |
487 | ||
488 | if ((t = tree_search(c->item_cache, keystring)) == NULL) | |
489 | { | |
490 | BOOL do_cache = TRUE; | |
491 | int keylength = Ustrlen(keystring); | |
492 | ||
493 | DEBUG(D_lookup) | |
494 | { | |
495 | if (filename != NULL) | |
496 | debug_printf("file lookup required for %s\n in %s\n", | |
497 | keystring, filename); | |
498 | else | |
499 | debug_printf("database lookup required for %s\n", keystring); | |
500 | } | |
501 | ||
502 | /* Call the code for the different kinds of search. DEFER is handled | |
503 | like FAIL, except that search_find_defer is set so the caller can | |
504 | distinguish if necessary. */ | |
505 | ||
506 | if (lookup_list[search_type].find(c->handle, filename, keystring, keylength, | |
507 | &data, &search_error_message, &do_cache) == DEFER) | |
508 | { | |
509 | search_find_defer = TRUE; | |
510 | } | |
511 | ||
512 | /* A record that has been found is now in data, which is either NULL | |
513 | or points to a bit of dynamic store. Cache the result of the lookup if | |
514 | caching is permitted. Lookups can disable caching, when they did something | |
515 | that changes their data. The mysql and pgsql lookups do this when an | |
516 | UPDATE/INSERT query was executed. */ | |
517 | ||
518 | else if (do_cache) | |
519 | { | |
520 | int len = keylength + 1; | |
521 | t = store_get(sizeof(tree_node) + len); | |
522 | memcpy(t->name, keystring, len); | |
523 | t->data.ptr = data; | |
524 | tree_insertnode(&c->item_cache, t); | |
525 | } | |
526 | ||
527 | /* If caching was disabled, empty the cache tree. We just set the cache | |
528 | pointer to NULL here, because we cannot release the store at this stage. */ | |
529 | ||
530 | else | |
531 | { | |
532 | DEBUG(D_lookup) debug_printf("lookup forced cache cleanup\n"); | |
533 | c->item_cache = NULL; | |
534 | } | |
535 | } | |
536 | ||
537 | /* Data was in the cache already; set the pointer from the tree node */ | |
538 | ||
539 | else | |
540 | { | |
541 | data = US t->data.ptr; | |
542 | DEBUG(D_lookup) debug_printf("cached data used for lookup of %s%s%s\n", | |
543 | keystring, | |
544 | (filename == NULL)? US"" : US"\n in ", | |
545 | (filename == NULL)? US"" : filename); | |
546 | } | |
547 | ||
548 | /* Debug: output the answer */ | |
549 | ||
550 | DEBUG(D_lookup) | |
551 | { | |
552 | if (data == NULL) | |
553 | { | |
554 | if (search_find_defer) debug_printf("lookup deferred: %s\n", | |
555 | search_error_message); | |
556 | else debug_printf("lookup failed\n"); | |
557 | } | |
558 | else debug_printf("lookup yielded: %s\n", data); | |
559 | } | |
560 | ||
561 | /* Return it in new dynamic store in the regular pool */ | |
562 | ||
563 | store_pool = old_pool; | |
564 | return (data == NULL)? NULL : string_copy(data); | |
565 | } | |
566 | ||
567 | ||
568 | ||
569 | ||
570 | /************************************************* | |
571 | * Find one item in database, possibly wildcarded * | |
572 | *************************************************/ | |
573 | ||
574 | /* This function calls the internal function above; once only if there | |
575 | is no partial matching, but repeatedly when partial matching is requested. | |
576 | ||
577 | Arguments: | |
578 | handle the handle from search_open | |
579 | filename the filename that was handed to search_open, or | |
580 | NULL for query-style searches | |
581 | keystring the keystring for single-key+file lookups, or | |
582 | the querystring for query-style lookups | |
583 | partial -1 means no partial matching; | |
584 | otherwise it's the minimum number of components; | |
585 | affix the affix string for partial matching | |
586 | affixlen the length of the affix string | |
587 | starflags SEARCH_STAR and SEARCH_STARAT flags | |
588 | expand_setup pointer to offset for setting up expansion strings; | |
589 | don't do any if < 0 | |
590 | ||
591 | Returns: a pointer to a dynamic string containing the answer, | |
592 | or NULL if the query failed or was deferred; in the | |
593 | latter case, search_find_defer is set TRUE | |
594 | */ | |
595 | ||
596 | uschar * | |
597 | search_find(void *handle, uschar *filename, uschar *keystring, int partial, | |
598 | uschar *affix, int affixlen, int starflags, int *expand_setup) | |
599 | { | |
600 | tree_node *t = (tree_node *)handle; | |
601 | BOOL set_null_wild = FALSE; | |
602 | uschar *yield; | |
603 | ||
604 | DEBUG(D_lookup) | |
605 | { | |
606 | if (partial < 0) affixlen = 99; /* So that "NULL" prints */ | |
607 | debug_printf("search_find: file=\"%s\"\n key=\"%s\" " | |
608 | "partial=%d affix=%.*s starflags=%x\n", | |
609 | (filename == NULL)? US"NULL" : filename, | |
610 | keystring, partial, affixlen, affix, starflags); | |
611 | } | |
612 | ||
613 | /* Arrange to put this database at the top of the LRU chain if it is a type | |
614 | that opens real files. */ | |
615 | ||
616 | if (open_top != (tree_node *)handle && | |
617 | lookup_list[t->name[0]-'0'].type == lookup_absfile) | |
618 | { | |
619 | search_cache *c = (search_cache *)(t->data.ptr); | |
620 | tree_node *up = c->up; | |
621 | tree_node *down = c->down; | |
622 | ||
623 | /* Cut it out of the list. A newly opened file will a NULL up pointer. | |
624 | Otherwise there will be a non-NULL up pointer, since we checked above that | |
625 | this block isn't already at the top of the list. */ | |
626 | ||
627 | if (up != NULL) | |
628 | { | |
629 | ((search_cache *)(up->data.ptr))->down = down; | |
630 | if (down != NULL) | |
631 | ((search_cache *)(down->data.ptr))->up = up; | |
632 | else open_bot = up; | |
633 | } | |
634 | ||
635 | /* Now put it at the head of the list. */ | |
636 | ||
637 | c->up = NULL; | |
638 | c->down = open_top; | |
639 | if (open_top == NULL) open_bot = t; else | |
640 | ((search_cache *)(open_top->data.ptr))->up = t; | |
641 | open_top = t; | |
642 | } | |
643 | ||
644 | DEBUG(D_lookup) | |
645 | { | |
646 | tree_node *t = open_top; | |
647 | debug_printf("LRU list:\n"); | |
648 | while (t != NULL) | |
649 | { | |
650 | search_cache *c = (search_cache *)(t->data.ptr); | |
651 | debug_printf(" %s\n", t->name); | |
652 | if (t == open_bot) debug_printf(" End\n"); | |
653 | t = c->down; | |
654 | } | |
655 | } | |
656 | ||
657 | /* First of all, try to match the key string verbatim. If matched a complete | |
658 | entry but could have been partial, flag to set up variables. */ | |
659 | ||
660 | yield = internal_search_find(handle, filename, keystring); | |
661 | if (search_find_defer) return NULL; | |
662 | if (yield != NULL) { if (partial >= 0) set_null_wild = TRUE; } | |
663 | ||
664 | /* Not matched a complete entry; handle partial lookups, but only if the full | |
665 | search didn't defer. Don't use string_sprintf() to construct the initial key, | |
666 | just in case the original key is too long for the string_sprintf() buffer (it | |
667 | *has* happened!). The case of a zero-length affix has to be treated specially. | |
668 | */ | |
669 | ||
670 | else if (partial >= 0) | |
671 | { | |
672 | int len = Ustrlen(keystring); | |
673 | uschar *keystring2; | |
674 | ||
675 | /* Try with the affix on the front, except for a zero-length affix */ | |
676 | ||
677 | if (affixlen == 0) keystring2 = keystring; else | |
678 | { | |
679 | keystring2 = store_get(len + affixlen + 1); | |
680 | Ustrncpy(keystring2, affix, affixlen); | |
681 | Ustrcpy(keystring2 + affixlen, keystring); | |
682 | DEBUG(D_lookup) debug_printf("trying partial match %s\n", keystring2); | |
683 | yield = internal_search_find(handle, filename, keystring2); | |
684 | if (search_find_defer) return NULL; | |
685 | } | |
686 | ||
687 | /* The key in its entirety did not match a wild entry; try chopping off | |
688 | leading components. */ | |
689 | ||
690 | if (yield == NULL) | |
691 | { | |
692 | int dotcount = 0; | |
693 | uschar *keystring3 = keystring2 + affixlen; | |
694 | uschar *s = keystring3; | |
695 | while (*s != 0) if (*s++ == '.') dotcount++; | |
696 | ||
697 | while (dotcount-- >= partial) | |
698 | { | |
699 | while (*keystring3 != 0 && *keystring3 != '.') keystring3++; | |
700 | ||
701 | /* If we get right to the end of the string (which will be the last time | |
702 | through this loop), we've failed if the affix is null. Otherwise do one | |
703 | last lookup for the affix itself, but if it is longer than 1 character, | |
704 | remove the last character if it is ".". */ | |
705 | ||
706 | if (*keystring3 == 0) | |
707 | { | |
708 | if (affixlen < 1) break; | |
709 | if (affixlen > 1 && affix[affixlen-1] == '.') affixlen--; | |
710 | Ustrncpy(keystring2, affix, affixlen); | |
711 | keystring2[affixlen] = 0; | |
712 | keystring3 = keystring2; | |
713 | } | |
714 | else | |
715 | { | |
716 | keystring3 -= affixlen - 1; | |
717 | if (affixlen > 0) Ustrncpy(keystring3, affix, affixlen); | |
718 | } | |
719 | ||
720 | DEBUG(D_lookup) debug_printf("trying partial match %s\n", keystring3); | |
721 | yield = internal_search_find(handle, filename, keystring3); | |
722 | if (search_find_defer) return NULL; | |
723 | if (yield != NULL) | |
724 | { | |
725 | /* First variable is the wild part; second is the fixed part. Take care | |
726 | to get it right when keystring3 is just "*". */ | |
727 | ||
728 | if (expand_setup != NULL && *expand_setup >= 0) | |
729 | { | |
730 | int fixedlength = Ustrlen(keystring3) - affixlen; | |
731 | int wildlength = Ustrlen(keystring) - fixedlength - 1; | |
732 | *expand_setup += 1; | |
733 | expand_nstring[*expand_setup] = keystring; | |
734 | expand_nlength[*expand_setup] = wildlength; | |
735 | *expand_setup += 1; | |
736 | expand_nstring[*expand_setup] = keystring + wildlength + 1; | |
737 | expand_nlength[*expand_setup] = (fixedlength < 0)? 0 : fixedlength; | |
738 | } | |
739 | break; | |
740 | } | |
741 | keystring3 += affixlen; | |
742 | } | |
743 | } | |
744 | ||
745 | else set_null_wild = TRUE; /* Matched a wild entry without any wild part */ | |
746 | } | |
747 | ||
748 | /* If nothing has been matched, but the option to look for "*@" is set, try | |
749 | replacing everthing to the left of @ by *. After a match, the wild part | |
750 | is set to the string to the left of the @. */ | |
751 | ||
752 | if (yield == NULL && (starflags & SEARCH_STARAT) != 0) | |
753 | { | |
754 | uschar *atat = Ustrrchr(keystring, '@'); | |
755 | if (atat != NULL && atat > keystring) | |
756 | { | |
757 | int savechar; | |
758 | savechar = *(--atat); | |
759 | *atat = '*'; | |
760 | ||
761 | DEBUG(D_lookup) debug_printf("trying default match %s\n", atat); | |
762 | yield = internal_search_find(handle, filename, atat); | |
763 | *atat = savechar; | |
764 | if (search_find_defer) return NULL; | |
765 | ||
766 | if (yield != NULL && expand_setup != NULL && *expand_setup >= 0) | |
767 | { | |
768 | *expand_setup += 1; | |
769 | expand_nstring[*expand_setup] = keystring; | |
770 | expand_nlength[*expand_setup] = atat - keystring + 1; | |
771 | *expand_setup += 1; | |
772 | expand_nstring[*expand_setup] = keystring; | |
773 | expand_nlength[*expand_setup] = 0; | |
774 | } | |
775 | } | |
776 | } | |
777 | ||
778 | /* If we still haven't matched anything, and the option to look for "*" is set, | |
779 | try that. If we do match, the first variable (the wild part) is the whole key, | |
780 | and the second is empty. */ | |
781 | ||
782 | if (yield == NULL && (starflags & (SEARCH_STAR|SEARCH_STARAT)) != 0) | |
783 | { | |
784 | DEBUG(D_lookup) debug_printf("trying to match *\n"); | |
785 | yield = internal_search_find(handle, filename, US"*"); | |
786 | if (yield != NULL && expand_setup != NULL && *expand_setup >= 0) | |
787 | { | |
788 | *expand_setup += 1; | |
789 | expand_nstring[*expand_setup] = keystring; | |
790 | expand_nlength[*expand_setup] = Ustrlen(keystring); | |
791 | *expand_setup += 1; | |
792 | expand_nstring[*expand_setup] = keystring; | |
793 | expand_nlength[*expand_setup] = 0; | |
794 | } | |
795 | } | |
796 | ||
797 | /* If this was a potentially partial lookup, and we matched either a | |
798 | complete non-wild domain entry, or we matched a wild-carded entry without | |
799 | chopping off any of the domain components, set up the expansion variables | |
800 | (if required) so that the first one is empty, and the second one is the | |
801 | fixed part of the domain. The set_null_wild flag is set only when yield is not | |
802 | NULL. */ | |
803 | ||
804 | if (set_null_wild && expand_setup != NULL && *expand_setup >= 0) | |
805 | { | |
806 | *expand_setup += 1; | |
807 | expand_nstring[*expand_setup] = keystring; | |
808 | expand_nlength[*expand_setup] = 0; | |
809 | *expand_setup += 1; | |
810 | expand_nstring[*expand_setup] = keystring; | |
811 | expand_nlength[*expand_setup] = Ustrlen(keystring); | |
812 | } | |
813 | ||
814 | return yield; | |
815 | } | |
816 | ||
817 | /* End of search.c */ |