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059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
3386088d | 5 | /* Copyright (c) University of Cambridge 1995 - 2015 */ |
059ec3d9 PH |
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 void *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 | |
55414b25 | 65 | search_findtype(const uschar *name, int len) |
059ec3d9 PH |
66 | { |
67 | int bot = 0; | |
68 | int top = lookup_list_count; | |
69 | while (top > bot) | |
70 | { | |
71 | int mid = (top + bot)/2; | |
e6d225ae | 72 | int c = Ustrncmp(name, lookup_list[mid]->name, len); |
059ec3d9 PH |
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 | ||
e6d225ae | 82 | if (c == 0 && Ustrlen(lookup_list[mid]->name) == len) |
059ec3d9 | 83 | { |
e6d225ae | 84 | if (lookup_list[mid]->find != NULL) return mid; |
059ec3d9 PH |
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 | ||
119 | Returns: +ve => valid lookup name; value is offset in lookup_list | |
120 | -ve => invalid name; message in search_error_message. | |
121 | */ | |
122 | ||
123 | int | |
55414b25 | 124 | search_findtype_partial(const uschar *name, int *ptypeptr, const uschar **ptypeaff, |
059ec3d9 PH |
125 | int *afflen, int *starflags) |
126 | { | |
127 | int len, stype; | |
128 | int pv = -1; | |
55414b25 | 129 | const uschar *ss = name; |
059ec3d9 PH |
130 | |
131 | *starflags = 0; | |
132 | *ptypeaff = NULL; | |
133 | ||
134 | /* Check for a partial matching type. It must start with "partial", optionally | |
135 | followed by a sequence of digits. If this is followed by "-", the affix is the | |
136 | default "*." string. Otherwise we expect an affix in parentheses. Affixes are a | |
137 | limited number of characters, not including parens. */ | |
138 | ||
139 | if (Ustrncmp(name, "partial", 7) == 0) | |
140 | { | |
141 | ss += 7; | |
142 | if (isdigit (*ss)) | |
143 | { | |
144 | pv = 0; | |
145 | while (isdigit(*ss)) pv = pv*10 + *ss++ - '0'; | |
146 | } | |
147 | else pv = 2; /* Default number of wild components */ | |
148 | ||
149 | if (*ss == '(') | |
150 | { | |
151 | *ptypeaff = ++ss; | |
152 | while (ispunct(*ss) && *ss != ')') ss++; | |
153 | if (*ss != ')') goto BAD_TYPE; | |
154 | *afflen = ss++ - *ptypeaff; | |
155 | } | |
156 | else if (*ss++ == '-') | |
157 | { | |
158 | *ptypeaff = US "*."; | |
159 | *afflen = 2; | |
160 | } | |
161 | else | |
162 | { | |
163 | BAD_TYPE: | |
164 | search_error_message = string_sprintf("format error in lookup type \"%s\"", | |
165 | name); | |
166 | return -1; | |
167 | } | |
168 | } | |
169 | ||
170 | /* Now we are left with a lookup name, possibly followed by * or *@. */ | |
171 | ||
172 | len = Ustrlen(ss); | |
173 | if (len >= 2 && Ustrncmp(ss + len - 2, "*@", 2) == 0) | |
174 | { | |
175 | *starflags |= SEARCH_STARAT; | |
176 | len -= 2; | |
177 | } | |
178 | else if (len >= 1 && ss[len-1] == '*') | |
179 | { | |
180 | *starflags |= SEARCH_STAR; | |
181 | len--; | |
182 | } | |
183 | ||
184 | /* Check for the individual search type. Only those that are actually in the | |
d7837193 PH |
185 | binary are valid. For query-style types, "partial" and default types are |
186 | erroneous. */ | |
059ec3d9 PH |
187 | |
188 | stype = search_findtype(ss, len); | |
d7837193 | 189 | if (stype >= 0 && mac_islookup(stype, lookup_querystyle)) |
059ec3d9 | 190 | { |
d7837193 PH |
191 | if (pv >= 0) |
192 | { | |
193 | search_error_message = string_sprintf("\"partial\" is not permitted " | |
194 | "for lookup type \"%s\"", ss); | |
195 | return -1; | |
196 | } | |
197 | if ((*starflags & (SEARCH_STAR|SEARCH_STARAT)) != 0) | |
198 | { | |
199 | search_error_message = string_sprintf("defaults using \"*\" or \"*@\" are " | |
200 | "not permitted for lookup type \"%s\"", ss); | |
201 | return -1; | |
202 | } | |
059ec3d9 PH |
203 | } |
204 | ||
059ec3d9 PH |
205 | *ptypeptr = pv; |
206 | return stype; | |
207 | } | |
208 | ||
209 | ||
210 | ||
211 | /************************************************* | |
212 | * Release cached resources * | |
213 | *************************************************/ | |
214 | ||
215 | /* When search_open is called it caches the "file" that it opens in | |
216 | search_tree. The name of the tree node is a concatenation of the search type | |
217 | with the file name. For query-style lookups, the file name is empty. Real files | |
218 | are normally closed only when this tidyup routine is called, typically at the | |
219 | end of sections of code where a number of lookups might occur. However, if too | |
220 | many files are open simultaneously, some get closed beforehand. They can't be | |
221 | removed from the tree. There is also a general tidyup function which is called | |
222 | for the lookup driver, if it exists. | |
223 | ||
224 | First, there is an internal, recursive subroutine. | |
225 | ||
226 | Argument: a pointer to a search_openfile tree node | |
227 | Returns: nothing | |
228 | */ | |
229 | ||
230 | static void | |
231 | tidyup_subtree(tree_node *t) | |
232 | { | |
233 | search_cache *c = (search_cache *)(t->data.ptr); | |
234 | if (t->left != NULL) tidyup_subtree(t->left); | |
235 | if (t->right != NULL) tidyup_subtree(t->right); | |
236 | if (c != NULL && | |
237 | c->handle != NULL && | |
e6d225ae DW |
238 | lookup_list[c->search_type]->close != NULL) |
239 | lookup_list[c->search_type]->close(c->handle); | |
059ec3d9 PH |
240 | } |
241 | ||
242 | ||
243 | /* The external entry point | |
244 | ||
245 | Argument: none | |
246 | Returns: nothing | |
247 | */ | |
248 | ||
249 | void | |
250 | search_tidyup(void) | |
251 | { | |
059ec3d9 PH |
252 | int old_pool = store_pool; |
253 | ||
254 | DEBUG(D_lookup) debug_printf("search_tidyup called\n"); | |
255 | ||
256 | /* Close individually each cached open file. */ | |
257 | ||
258 | store_pool = POOL_SEARCH; | |
d7978c0f | 259 | if (search_tree) |
059ec3d9 PH |
260 | { |
261 | tidyup_subtree(search_tree); | |
262 | search_tree = NULL; | |
263 | } | |
264 | open_top = open_bot = NULL; | |
265 | open_filecount = 0; | |
266 | ||
267 | /* Call the general tidyup entry for any drivers that have one. */ | |
268 | ||
d7978c0f JH |
269 | for (int i = 0; i < lookup_list_count; i++) if (lookup_list[i]->tidy) |
270 | (lookup_list[i]->tidy)(); | |
059ec3d9 | 271 | |
d7978c0f | 272 | if (search_reset_point) store_reset(search_reset_point); |
059ec3d9 PH |
273 | search_reset_point = NULL; |
274 | store_pool = old_pool; | |
275 | } | |
276 | ||
277 | ||
278 | ||
279 | ||
280 | /************************************************* | |
281 | * Open search database * | |
282 | *************************************************/ | |
283 | ||
284 | /* A mode, and lists of owners and groups, are passed over for checking in | |
285 | the cases where the database is one or more files. Return NULL, with a message | |
286 | pointed to by message, in cases of error. | |
287 | ||
288 | For search types that use a file or files, check up on the mode after | |
289 | opening. It is tempting to do a stat before opening the file, and use it as | |
290 | an existence check. However, doing that opens a small security loophole in | |
291 | that the status could be changed before the file is opened. Can't quite see | |
292 | what problems this might lead to, but you can't be too careful where security | |
293 | is concerned. Fstat() on an open file can normally be expected to succeed, | |
294 | but there are some NFS states where it does not. | |
295 | ||
296 | There are two styles of query: (1) in the "single-key+file" style, a single | |
297 | key string and a file name are given, for example, for linear searches, DBM | |
298 | files, or for NIS. (2) In the "query" style, no "filename" is given; instead | |
299 | just a single query string is passed. This applies to multiple-key lookup | |
300 | types such as NIS+. | |
301 | ||
302 | Before opening, scan the tree of cached files to see if this file is already | |
303 | open for the correct search type. If so, return the saved handle. If not, put | |
304 | the handle in the tree for possible subsequent use. See search_tidyup above for | |
305 | closing all the cached files. | |
306 | ||
307 | A count of open databases which use real files is maintained, and if this | |
308 | gets too large, we have to close a cached file. Its entry remains in the tree, | |
309 | but is marked closed. | |
310 | ||
311 | Arguments: | |
312 | filename the name of the file for single-key+file style lookups, | |
313 | NULL for query-style lookups | |
314 | search_type the type of search required | |
315 | modemask if a real single file is used, this specifies mode bits that | |
316 | must not be set; otherwise it is ignored | |
317 | owners if a real single file is used, this specifies the possible | |
318 | owners of the file; otherwise it is ignored | |
319 | owngroups if a real single file is used, this specifies the possible | |
320 | group owners of the file; otherwise it is ignored | |
321 | ||
322 | Returns: an identifying handle for the open database; | |
323 | this is the pointer to the tree block in the | |
324 | cache of open files; return NULL on open failure, with | |
325 | a message in search_error_message | |
326 | */ | |
327 | ||
328 | void * | |
329 | search_open(uschar *filename, int search_type, int modemask, uid_t *owners, | |
330 | gid_t *owngroups) | |
331 | { | |
332 | void *handle; | |
333 | tree_node *t; | |
334 | search_cache *c; | |
e6d225ae | 335 | lookup_info *lk = lookup_list[search_type]; |
059ec3d9 PH |
336 | uschar keybuffer[256]; |
337 | int old_pool = store_pool; | |
338 | ||
339 | /* Change to the search store pool and remember our reset point */ | |
340 | ||
341 | store_pool = POOL_SEARCH; | |
342 | if (search_reset_point == NULL) search_reset_point = store_get(0); | |
343 | ||
344 | DEBUG(D_lookup) debug_printf("search_open: %s \"%s\"\n", lk->name, | |
345 | (filename == NULL)? US"NULL" : filename); | |
346 | ||
347 | /* See if we already have this open for this type of search, and if so, | |
348 | pass back the tree block as the handle. The key for the tree node is the search | |
349 | type plus '0' concatenated with the file name. There may be entries in the tree | |
350 | with closed files if a lot of files have been opened. */ | |
351 | ||
352 | sprintf(CS keybuffer, "%c%.254s", search_type + '0', | |
353 | (filename == NULL)? US"" : filename); | |
354 | ||
355 | if ((t = tree_search(search_tree, keybuffer)) != NULL) | |
356 | { | |
357 | c = (search_cache *)(t->data.ptr); | |
358 | if (c->handle != NULL) | |
359 | { | |
360 | DEBUG(D_lookup) debug_printf(" cached open\n"); | |
361 | store_pool = old_pool; | |
362 | return t; | |
363 | } | |
364 | DEBUG(D_lookup) debug_printf(" cached closed\n"); | |
365 | } | |
366 | ||
367 | /* Otherwise, we need to open the file or database - each search type has its | |
368 | own code, which is now split off into separately compiled modules. Before doing | |
369 | this, if the search type is one that uses real files, check on the number that | |
370 | we are holding open in the cache. If the limit is reached, close the least | |
371 | recently used one. */ | |
372 | ||
373 | if (lk->type == lookup_absfile && open_filecount >= lookup_open_max) | |
374 | { | |
375 | if (open_bot == NULL) | |
376 | log_write(0, LOG_MAIN|LOG_PANIC, "too many lookups open, but can't find " | |
377 | "one to close"); | |
378 | else | |
379 | { | |
380 | search_cache *c = (search_cache *)(open_bot->data.ptr); | |
381 | DEBUG(D_lookup) debug_printf("Too many lookup files open\n closing %s\n", | |
382 | open_bot->name); | |
383 | open_bot = c->up; | |
384 | if (open_bot != NULL) | |
385 | ((search_cache *)(open_bot->data.ptr))->down = NULL; | |
386 | else | |
387 | open_top = NULL; | |
e6d225ae | 388 | ((lookup_list[c->search_type])->close)(c->handle); |
059ec3d9 PH |
389 | c->handle = NULL; |
390 | open_filecount--; | |
391 | } | |
392 | } | |
393 | ||
394 | /* If opening is successful, call the file-checking function if there is one, | |
395 | and if all is still well, enter the open database into the tree. */ | |
396 | ||
19897d52 | 397 | handle = (lk->open)(filename, &search_error_message); |
059ec3d9 PH |
398 | if (handle == NULL) |
399 | { | |
400 | store_pool = old_pool; | |
401 | return NULL; | |
402 | } | |
403 | ||
404 | if (lk->check != NULL && | |
405 | !lk->check(handle, filename, modemask, owners, owngroups, | |
406 | &search_error_message)) | |
407 | { | |
408 | lk->close(handle); | |
409 | store_pool = old_pool; | |
410 | return NULL; | |
411 | } | |
412 | ||
413 | /* If this is a search type that uses real files, keep count. */ | |
414 | ||
415 | if (lk->type == lookup_absfile) open_filecount++; | |
416 | ||
417 | /* If we found a previously opened entry in the tree, re-use it; otherwise | |
418 | insert a new entry. On re-use, leave any cached lookup data and the lookup | |
419 | count alone. */ | |
420 | ||
421 | if (t == NULL) | |
422 | { | |
423 | t = store_get(sizeof(tree_node) + Ustrlen(keybuffer)); | |
424 | t->data.ptr = c = store_get(sizeof(search_cache)); | |
425 | c->item_cache = NULL; | |
426 | Ustrcpy(t->name, keybuffer); | |
427 | tree_insertnode(&search_tree, t); | |
428 | } | |
429 | else c = t->data.ptr; | |
430 | ||
431 | c->handle = handle; | |
432 | c->search_type = search_type; | |
433 | c->up = c->down = NULL; | |
434 | ||
435 | store_pool = old_pool; | |
436 | return t; | |
437 | } | |
438 | ||
439 | ||
440 | ||
441 | ||
442 | ||
443 | /************************************************* | |
444 | * Internal function: Find one item in database * | |
445 | *************************************************/ | |
446 | ||
447 | /* The answer is always put into dynamic store. The last lookup for each handle | |
448 | is cached. | |
449 | ||
450 | Arguments: | |
451 | handle the handle from search_open; points to tree node | |
452 | filename the filename that was handed to search_open, or | |
453 | NULL for query-style searches | |
454 | keystring the keystring for single-key+file lookups, or | |
455 | the querystring for query-style lookups | |
456 | ||
457 | Returns: a pointer to a dynamic string containing the answer, | |
458 | or NULL if the query failed or was deferred; in the | |
459 | latter case, search_find_defer is set TRUE; after an unusual | |
460 | failure, there may be a message in search_error_message. | |
461 | */ | |
462 | ||
463 | static uschar * | |
464 | internal_search_find(void *handle, uschar *filename, uschar *keystring) | |
465 | { | |
0488984d JH |
466 | tree_node * t = (tree_node *)handle; |
467 | search_cache * c = (search_cache *)(t->data.ptr); | |
468 | expiring_data * e = NULL; /* compiler quietening */ | |
469 | uschar * data = NULL; | |
059ec3d9 PH |
470 | int search_type = t->name[0] - '0'; |
471 | int old_pool = store_pool; | |
472 | ||
473 | /* Lookups that return DEFER may not always set an error message. So that | |
474 | the callers don't have to test for NULL, set an empty string. */ | |
475 | ||
476 | search_error_message = US""; | |
8768d548 | 477 | f.search_find_defer = FALSE; |
059ec3d9 PH |
478 | |
479 | DEBUG(D_lookup) debug_printf("internal_search_find: file=\"%s\"\n " | |
480 | "type=%s key=\"%s\"\n", filename, | |
e6d225ae | 481 | lookup_list[search_type]->name, keystring); |
059ec3d9 PH |
482 | |
483 | /* Insurance. If the keystring is empty, just fail. */ | |
484 | ||
485 | if (keystring[0] == 0) return NULL; | |
486 | ||
487 | /* Use the special store pool for search data */ | |
488 | ||
489 | store_pool = POOL_SEARCH; | |
490 | ||
491 | /* Look up the data for the key, unless it is already in the cache for this | |
492 | file. No need to check c->item_cache for NULL, tree_search will do so. */ | |
493 | ||
14b3c5bc JH |
494 | if ( (t = tree_search(c->item_cache, keystring)) |
495 | && (!(e = t->data.ptr)->expiry || e->expiry > time(NULL)) | |
496 | ) | |
497 | { /* Data was in the cache already; set the pointer from the tree node */ | |
498 | data = e->ptr; | |
499 | DEBUG(D_lookup) debug_printf("cached data used for lookup of %s%s%s\n", | |
500 | keystring, | |
501 | filename ? US"\n in " : US"", filename ? filename : US""); | |
502 | } | |
503 | else | |
059ec3d9 | 504 | { |
14b3c5bc | 505 | uint do_cache = UINT_MAX; |
059ec3d9 PH |
506 | int keylength = Ustrlen(keystring); |
507 | ||
508 | DEBUG(D_lookup) | |
509 | { | |
14b3c5bc JH |
510 | if (t) debug_printf("cached data found but past valid time; "); |
511 | debug_printf("%s lookup required for %s%s%s\n", | |
512 | filename ? US"file" : US"database", | |
513 | keystring, | |
514 | filename ? US"\n in " : US"", filename ? filename : US""); | |
059ec3d9 PH |
515 | } |
516 | ||
517 | /* Call the code for the different kinds of search. DEFER is handled | |
518 | like FAIL, except that search_find_defer is set so the caller can | |
519 | distinguish if necessary. */ | |
520 | ||
e6d225ae | 521 | if (lookup_list[search_type]->find(c->handle, filename, keystring, keylength, |
059ec3d9 | 522 | &data, &search_error_message, &do_cache) == DEFER) |
8768d548 | 523 | f.search_find_defer = TRUE; |
059ec3d9 PH |
524 | |
525 | /* A record that has been found is now in data, which is either NULL | |
526 | or points to a bit of dynamic store. Cache the result of the lookup if | |
527 | caching is permitted. Lookups can disable caching, when they did something | |
528 | that changes their data. The mysql and pgsql lookups do this when an | |
529 | UPDATE/INSERT query was executed. */ | |
530 | ||
531 | else if (do_cache) | |
532 | { | |
533 | int len = keylength + 1; | |
14b3c5bc JH |
534 | |
535 | if (t) /* Previous, out-of-date cache entry. Update with the */ | |
536 | { /* new result and forget the old one */ | |
537 | e->expiry = do_cache == UINT_MAX ? 0 : time(NULL)+do_cache; | |
538 | e->ptr = data; | |
539 | } | |
540 | else | |
541 | { | |
98b98887 | 542 | e = store_get(sizeof(expiring_data) + sizeof(tree_node) + len); |
14b3c5bc JH |
543 | e->expiry = do_cache == UINT_MAX ? 0 : time(NULL)+do_cache; |
544 | e->ptr = data; | |
98b98887 | 545 | t = (tree_node *)(e+1); |
14b3c5bc JH |
546 | memcpy(t->name, keystring, len); |
547 | t->data.ptr = e; | |
548 | tree_insertnode(&c->item_cache, t); | |
549 | } | |
059ec3d9 PH |
550 | } |
551 | ||
552 | /* If caching was disabled, empty the cache tree. We just set the cache | |
553 | pointer to NULL here, because we cannot release the store at this stage. */ | |
554 | ||
555 | else | |
556 | { | |
557 | DEBUG(D_lookup) debug_printf("lookup forced cache cleanup\n"); | |
558 | c->item_cache = NULL; | |
559 | } | |
560 | } | |
561 | ||
059ec3d9 PH |
562 | DEBUG(D_lookup) |
563 | { | |
14b3c5bc JH |
564 | if (data) |
565 | debug_printf("lookup yielded: %s\n", data); | |
8768d548 | 566 | else if (f.search_find_defer) |
14b3c5bc JH |
567 | debug_printf("lookup deferred: %s\n", search_error_message); |
568 | else debug_printf("lookup failed\n"); | |
059ec3d9 PH |
569 | } |
570 | ||
571 | /* Return it in new dynamic store in the regular pool */ | |
572 | ||
573 | store_pool = old_pool; | |
14b3c5bc | 574 | return data ? string_copy(data) : NULL; |
059ec3d9 PH |
575 | } |
576 | ||
577 | ||
578 | ||
579 | ||
580 | /************************************************* | |
581 | * Find one item in database, possibly wildcarded * | |
582 | *************************************************/ | |
583 | ||
584 | /* This function calls the internal function above; once only if there | |
585 | is no partial matching, but repeatedly when partial matching is requested. | |
586 | ||
587 | Arguments: | |
588 | handle the handle from search_open | |
589 | filename the filename that was handed to search_open, or | |
590 | NULL for query-style searches | |
591 | keystring the keystring for single-key+file lookups, or | |
592 | the querystring for query-style lookups | |
593 | partial -1 means no partial matching; | |
594 | otherwise it's the minimum number of components; | |
595 | affix the affix string for partial matching | |
596 | affixlen the length of the affix string | |
597 | starflags SEARCH_STAR and SEARCH_STARAT flags | |
598 | expand_setup pointer to offset for setting up expansion strings; | |
599 | don't do any if < 0 | |
600 | ||
601 | Returns: a pointer to a dynamic string containing the answer, | |
602 | or NULL if the query failed or was deferred; in the | |
603 | latter case, search_find_defer is set TRUE | |
604 | */ | |
605 | ||
606 | uschar * | |
607 | search_find(void *handle, uschar *filename, uschar *keystring, int partial, | |
55414b25 | 608 | const uschar *affix, int affixlen, int starflags, int *expand_setup) |
059ec3d9 PH |
609 | { |
610 | tree_node *t = (tree_node *)handle; | |
611 | BOOL set_null_wild = FALSE; | |
612 | uschar *yield; | |
613 | ||
614 | DEBUG(D_lookup) | |
615 | { | |
616 | if (partial < 0) affixlen = 99; /* So that "NULL" prints */ | |
617 | debug_printf("search_find: file=\"%s\"\n key=\"%s\" " | |
618 | "partial=%d affix=%.*s starflags=%x\n", | |
619 | (filename == NULL)? US"NULL" : filename, | |
620 | keystring, partial, affixlen, affix, starflags); | |
621 | } | |
622 | ||
623 | /* Arrange to put this database at the top of the LRU chain if it is a type | |
624 | that opens real files. */ | |
625 | ||
626 | if (open_top != (tree_node *)handle && | |
e6d225ae | 627 | lookup_list[t->name[0]-'0']->type == lookup_absfile) |
059ec3d9 PH |
628 | { |
629 | search_cache *c = (search_cache *)(t->data.ptr); | |
630 | tree_node *up = c->up; | |
631 | tree_node *down = c->down; | |
632 | ||
633 | /* Cut it out of the list. A newly opened file will a NULL up pointer. | |
634 | Otherwise there will be a non-NULL up pointer, since we checked above that | |
635 | this block isn't already at the top of the list. */ | |
636 | ||
637 | if (up != NULL) | |
638 | { | |
639 | ((search_cache *)(up->data.ptr))->down = down; | |
640 | if (down != NULL) | |
641 | ((search_cache *)(down->data.ptr))->up = up; | |
642 | else open_bot = up; | |
643 | } | |
644 | ||
645 | /* Now put it at the head of the list. */ | |
646 | ||
647 | c->up = NULL; | |
648 | c->down = open_top; | |
649 | if (open_top == NULL) open_bot = t; else | |
650 | ((search_cache *)(open_top->data.ptr))->up = t; | |
651 | open_top = t; | |
652 | } | |
653 | ||
654 | DEBUG(D_lookup) | |
655 | { | |
656 | tree_node *t = open_top; | |
657 | debug_printf("LRU list:\n"); | |
658 | while (t != NULL) | |
659 | { | |
660 | search_cache *c = (search_cache *)(t->data.ptr); | |
661 | debug_printf(" %s\n", t->name); | |
662 | if (t == open_bot) debug_printf(" End\n"); | |
663 | t = c->down; | |
664 | } | |
665 | } | |
666 | ||
667 | /* First of all, try to match the key string verbatim. If matched a complete | |
668 | entry but could have been partial, flag to set up variables. */ | |
669 | ||
670 | yield = internal_search_find(handle, filename, keystring); | |
8768d548 | 671 | if (f.search_find_defer) return NULL; |
059ec3d9 PH |
672 | if (yield != NULL) { if (partial >= 0) set_null_wild = TRUE; } |
673 | ||
674 | /* Not matched a complete entry; handle partial lookups, but only if the full | |
675 | search didn't defer. Don't use string_sprintf() to construct the initial key, | |
676 | just in case the original key is too long for the string_sprintf() buffer (it | |
677 | *has* happened!). The case of a zero-length affix has to be treated specially. | |
678 | */ | |
679 | ||
680 | else if (partial >= 0) | |
681 | { | |
682 | int len = Ustrlen(keystring); | |
683 | uschar *keystring2; | |
684 | ||
685 | /* Try with the affix on the front, except for a zero-length affix */ | |
686 | ||
687 | if (affixlen == 0) keystring2 = keystring; else | |
688 | { | |
689 | keystring2 = store_get(len + affixlen + 1); | |
690 | Ustrncpy(keystring2, affix, affixlen); | |
691 | Ustrcpy(keystring2 + affixlen, keystring); | |
692 | DEBUG(D_lookup) debug_printf("trying partial match %s\n", keystring2); | |
693 | yield = internal_search_find(handle, filename, keystring2); | |
8768d548 | 694 | if (f.search_find_defer) return NULL; |
059ec3d9 PH |
695 | } |
696 | ||
697 | /* The key in its entirety did not match a wild entry; try chopping off | |
698 | leading components. */ | |
699 | ||
700 | if (yield == NULL) | |
701 | { | |
702 | int dotcount = 0; | |
703 | uschar *keystring3 = keystring2 + affixlen; | |
704 | uschar *s = keystring3; | |
705 | while (*s != 0) if (*s++ == '.') dotcount++; | |
706 | ||
707 | while (dotcount-- >= partial) | |
708 | { | |
709 | while (*keystring3 != 0 && *keystring3 != '.') keystring3++; | |
710 | ||
711 | /* If we get right to the end of the string (which will be the last time | |
712 | through this loop), we've failed if the affix is null. Otherwise do one | |
713 | last lookup for the affix itself, but if it is longer than 1 character, | |
714 | remove the last character if it is ".". */ | |
715 | ||
716 | if (*keystring3 == 0) | |
717 | { | |
718 | if (affixlen < 1) break; | |
719 | if (affixlen > 1 && affix[affixlen-1] == '.') affixlen--; | |
720 | Ustrncpy(keystring2, affix, affixlen); | |
721 | keystring2[affixlen] = 0; | |
722 | keystring3 = keystring2; | |
723 | } | |
724 | else | |
725 | { | |
726 | keystring3 -= affixlen - 1; | |
727 | if (affixlen > 0) Ustrncpy(keystring3, affix, affixlen); | |
728 | } | |
729 | ||
730 | DEBUG(D_lookup) debug_printf("trying partial match %s\n", keystring3); | |
731 | yield = internal_search_find(handle, filename, keystring3); | |
8768d548 | 732 | if (f.search_find_defer) return NULL; |
059ec3d9 PH |
733 | if (yield != NULL) |
734 | { | |
735 | /* First variable is the wild part; second is the fixed part. Take care | |
736 | to get it right when keystring3 is just "*". */ | |
737 | ||
738 | if (expand_setup != NULL && *expand_setup >= 0) | |
739 | { | |
740 | int fixedlength = Ustrlen(keystring3) - affixlen; | |
741 | int wildlength = Ustrlen(keystring) - fixedlength - 1; | |
742 | *expand_setup += 1; | |
743 | expand_nstring[*expand_setup] = keystring; | |
744 | expand_nlength[*expand_setup] = wildlength; | |
745 | *expand_setup += 1; | |
746 | expand_nstring[*expand_setup] = keystring + wildlength + 1; | |
747 | expand_nlength[*expand_setup] = (fixedlength < 0)? 0 : fixedlength; | |
748 | } | |
749 | break; | |
750 | } | |
751 | keystring3 += affixlen; | |
752 | } | |
753 | } | |
754 | ||
755 | else set_null_wild = TRUE; /* Matched a wild entry without any wild part */ | |
756 | } | |
757 | ||
758 | /* If nothing has been matched, but the option to look for "*@" is set, try | |
4c04137d | 759 | replacing everything to the left of @ by *. After a match, the wild part |
059ec3d9 PH |
760 | is set to the string to the left of the @. */ |
761 | ||
762 | if (yield == NULL && (starflags & SEARCH_STARAT) != 0) | |
763 | { | |
764 | uschar *atat = Ustrrchr(keystring, '@'); | |
765 | if (atat != NULL && atat > keystring) | |
766 | { | |
767 | int savechar; | |
768 | savechar = *(--atat); | |
769 | *atat = '*'; | |
770 | ||
771 | DEBUG(D_lookup) debug_printf("trying default match %s\n", atat); | |
772 | yield = internal_search_find(handle, filename, atat); | |
773 | *atat = savechar; | |
8768d548 | 774 | if (f.search_find_defer) return NULL; |
059ec3d9 PH |
775 | |
776 | if (yield != NULL && expand_setup != NULL && *expand_setup >= 0) | |
777 | { | |
778 | *expand_setup += 1; | |
779 | expand_nstring[*expand_setup] = keystring; | |
780 | expand_nlength[*expand_setup] = atat - keystring + 1; | |
781 | *expand_setup += 1; | |
782 | expand_nstring[*expand_setup] = keystring; | |
783 | expand_nlength[*expand_setup] = 0; | |
784 | } | |
785 | } | |
786 | } | |
787 | ||
788 | /* If we still haven't matched anything, and the option to look for "*" is set, | |
789 | try that. If we do match, the first variable (the wild part) is the whole key, | |
790 | and the second is empty. */ | |
791 | ||
792 | if (yield == NULL && (starflags & (SEARCH_STAR|SEARCH_STARAT)) != 0) | |
793 | { | |
794 | DEBUG(D_lookup) debug_printf("trying to match *\n"); | |
795 | yield = internal_search_find(handle, filename, US"*"); | |
796 | if (yield != NULL && expand_setup != NULL && *expand_setup >= 0) | |
797 | { | |
798 | *expand_setup += 1; | |
799 | expand_nstring[*expand_setup] = keystring; | |
800 | expand_nlength[*expand_setup] = Ustrlen(keystring); | |
801 | *expand_setup += 1; | |
802 | expand_nstring[*expand_setup] = keystring; | |
803 | expand_nlength[*expand_setup] = 0; | |
804 | } | |
805 | } | |
806 | ||
807 | /* If this was a potentially partial lookup, and we matched either a | |
808 | complete non-wild domain entry, or we matched a wild-carded entry without | |
809 | chopping off any of the domain components, set up the expansion variables | |
810 | (if required) so that the first one is empty, and the second one is the | |
811 | fixed part of the domain. The set_null_wild flag is set only when yield is not | |
812 | NULL. */ | |
813 | ||
814 | if (set_null_wild && expand_setup != NULL && *expand_setup >= 0) | |
815 | { | |
816 | *expand_setup += 1; | |
817 | expand_nstring[*expand_setup] = keystring; | |
818 | expand_nlength[*expand_setup] = 0; | |
819 | *expand_setup += 1; | |
820 | expand_nstring[*expand_setup] = keystring; | |
821 | expand_nlength[*expand_setup] = Ustrlen(keystring); | |
822 | } | |
823 | ||
824 | return yield; | |
825 | } | |
826 | ||
827 | /* End of search.c */ |