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