readsocket expansion: response caching
[exim.git] / src / src / search.c
CommitLineData
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1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
3386088d 5/* Copyright (c) University of Cambridge 1995 - 2015 */
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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
9database is represented by a void * value which is returned from a lookup-
10specific "open" function. These are now all held in individual modules in the
11lookups subdirectory and the functions here form a generic interface.
12
13Caching is used to improve performance. Open files are cached until a tidyup
14function is called, and for each file the result of the last lookup is cached.
15However, if too many files are opened, some of those that are not in use have
16to be closed. Those open items that use real files are kept on a LRU chain to
17help with this.
18
19All the data is held in permanent store so as to be independent of the stacking
20pool that is reset from time to time. In fact, we use malloc'd store so that it
21can be freed when the caches are tidied up. It isn't actually clear whether
22this 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
29static tree_node *search_tree = NULL;
30
31/* Two-way chain of open databases that use real files. This is maintained in
32recently-used order for the purposes of closing the least recently used when
33too many files are open. */
34
35static tree_node *open_top = NULL;
36static tree_node *open_bot = NULL;
37
38/* Count of open databases that use real files */
39
40static int open_filecount = 0;
41
42/* Allow us to reset store used for lookups and lookup caching */
43
f3ebb786 44static rmark search_reset_point = NULL;
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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
53binary give an OK response. Use a binary chop search now that the list has got
54so long.
55
56Arguments:
57 name lookup type name - not necessarily zero terminated (e.g. dbm*)
58 len length of the name
59
60Returns: +ve => valid lookup name; value is offset in lookup_list
61 -ve => invalid name; message in search_error_message.
62*/
63
64int
55414b25 65search_findtype(const uschar *name, int len)
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66{
67int bot = 0;
68int top = lookup_list_count;
69while (top > bot)
70 {
71 int mid = (top + bot)/2;
e6d225ae 72 int c = Ustrncmp(name, lookup_list[mid]->name, len);
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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;
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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
94search_error_message = string_sprintf("unknown lookup type \"%.*s\"",len,name);
95return -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 *@
105suffixes.
106
107Arguments:
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
67a57a5a 118 opts where to put the options
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119
120Returns: +ve => valid lookup name; value is offset in lookup_list
121 -ve => invalid name; message in search_error_message.
122*/
123
124int
55414b25 125search_findtype_partial(const uschar *name, int *ptypeptr, const uschar **ptypeaff,
67a57a5a 126 int *afflen, int *starflags, const uschar ** opts)
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127{
128int len, stype;
129int pv = -1;
55414b25 130const uschar *ss = name;
67a57a5a 131const uschar * t;
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132
133*starflags = 0;
134*ptypeaff = NULL;
135
136/* Check for a partial matching type. It must start with "partial", optionally
137followed by a sequence of digits. If this is followed by "-", the affix is the
138default "*." string. Otherwise we expect an affix in parentheses. Affixes are a
139limited number of characters, not including parens. */
140
141if (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
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172/* Now we are left with a lookup name, possibly followed by * or *@,
173and then by options starting with a "," */
059ec3d9 174
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175len = Ustrlen(ss);
176if ((t = Ustrchr(ss, '*')))
177 {
178 len = t - ss;
179 *starflags |= (t[1] == '@' ? SEARCH_STARAT : SEARCH_STAR);
180 }
181else
182 t = ss;
183
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184if ((t = Ustrchr(t, ',')))
185 {
186 int l = t - ss;
187 if (l < len) len = l;
188 *opts = string_copy(t+1);
189 }
190else
191 * opts = NULL;
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192
193/* Check for the individual search type. Only those that are actually in the
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194binary are valid. For query-style types, "partial" and default types are
195erroneous. */
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196
197stype = search_findtype(ss, len);
d7837193 198if (stype >= 0 && mac_islookup(stype, lookup_querystyle))
059ec3d9 199 {
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200 if (pv >= 0)
201 {
202 search_error_message = string_sprintf("\"partial\" is not permitted "
203 "for lookup type \"%s\"", ss);
204 return -1;
205 }
206 if ((*starflags & (SEARCH_STAR|SEARCH_STARAT)) != 0)
207 {
208 search_error_message = string_sprintf("defaults using \"*\" or \"*@\" are "
209 "not permitted for lookup type \"%s\"", ss);
210 return -1;
211 }
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212 }
213
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214*ptypeptr = pv;
215return stype;
216}
217
218
219
220/*************************************************
221* Release cached resources *
222*************************************************/
223
224/* When search_open is called it caches the "file" that it opens in
225search_tree. The name of the tree node is a concatenation of the search type
226with the file name. For query-style lookups, the file name is empty. Real files
227are normally closed only when this tidyup routine is called, typically at the
228end of sections of code where a number of lookups might occur. However, if too
229many files are open simultaneously, some get closed beforehand. They can't be
230removed from the tree. There is also a general tidyup function which is called
231for the lookup driver, if it exists.
232
233First, there is an internal, recursive subroutine.
234
235Argument: a pointer to a search_openfile tree node
236Returns: nothing
237*/
238
239static void
240tidyup_subtree(tree_node *t)
241{
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242search_cache * c = (search_cache *)(t->data.ptr);
243if (t->left) tidyup_subtree(t->left);
244if (t->right) tidyup_subtree(t->right);
245if (c && c->handle && lookup_list[c->search_type]->close)
e6d225ae 246 lookup_list[c->search_type]->close(c->handle);
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247}
248
249
250/* The external entry point
251
252Argument: none
253Returns: nothing
254*/
255
256void
257search_tidyup(void)
258{
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259int old_pool = store_pool;
260
42c7f0b4 261DEBUG(D_lookup) debug_printf_indent("search_tidyup called\n");
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262
263/* Close individually each cached open file. */
264
265store_pool = POOL_SEARCH;
d7978c0f 266if (search_tree)
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267 {
268 tidyup_subtree(search_tree);
269 search_tree = NULL;
270 }
271open_top = open_bot = NULL;
272open_filecount = 0;
273
274/* Call the general tidyup entry for any drivers that have one. */
275
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276for (int i = 0; i < lookup_list_count; i++) if (lookup_list[i]->tidy)
277 (lookup_list[i]->tidy)();
059ec3d9 278
f3ebb786 279if (search_reset_point) search_reset_point = store_reset(search_reset_point);
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280store_pool = old_pool;
281}
282
283
284
285
286/*************************************************
287* Open search database *
288*************************************************/
289
290/* A mode, and lists of owners and groups, are passed over for checking in
291the cases where the database is one or more files. Return NULL, with a message
292pointed to by message, in cases of error.
293
294For search types that use a file or files, check up on the mode after
295opening. It is tempting to do a stat before opening the file, and use it as
296an existence check. However, doing that opens a small security loophole in
297that the status could be changed before the file is opened. Can't quite see
298what problems this might lead to, but you can't be too careful where security
299is concerned. Fstat() on an open file can normally be expected to succeed,
300but there are some NFS states where it does not.
301
302There are two styles of query: (1) in the "single-key+file" style, a single
303key string and a file name are given, for example, for linear searches, DBM
304files, or for NIS. (2) In the "query" style, no "filename" is given; instead
305just a single query string is passed. This applies to multiple-key lookup
306types such as NIS+.
307
308Before opening, scan the tree of cached files to see if this file is already
309open for the correct search type. If so, return the saved handle. If not, put
310the handle in the tree for possible subsequent use. See search_tidyup above for
311closing all the cached files.
312
313A count of open databases which use real files is maintained, and if this
314gets too large, we have to close a cached file. Its entry remains in the tree,
315but is marked closed.
316
317Arguments:
318 filename the name of the file for single-key+file style lookups,
319 NULL for query-style lookups
320 search_type the type of search required
321 modemask if a real single file is used, this specifies mode bits that
322 must not be set; otherwise it is ignored
323 owners if a real single file is used, this specifies the possible
324 owners of the file; otherwise it is ignored
325 owngroups if a real single file is used, this specifies the possible
326 group owners of the file; otherwise it is ignored
327
328Returns: an identifying handle for the open database;
329 this is the pointer to the tree block in the
330 cache of open files; return NULL on open failure, with
331 a message in search_error_message
332*/
333
334void *
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335search_open(const uschar * filename, int search_type, int modemask,
336 uid_t * owners, gid_t * owngroups)
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337{
338void *handle;
339tree_node *t;
340search_cache *c;
e6d225ae 341lookup_info *lk = lookup_list[search_type];
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342uschar keybuffer[256];
343int old_pool = store_pool;
344
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345if (filename && is_tainted(filename))
346 {
347 log_write(0, LOG_MAIN|LOG_PANIC,
348 "Tainted filename for search: '%s'", filename);
349 return NULL;
350 }
351
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352/* Change to the search store pool and remember our reset point */
353
354store_pool = POOL_SEARCH;
f3ebb786 355if (!search_reset_point) search_reset_point = store_mark();
059ec3d9 356
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357DEBUG(D_lookup) debug_printf_indent("search_open: %s \"%s\"\n", lk->name,
358 filename ? filename : US"NULL");
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359
360/* See if we already have this open for this type of search, and if so,
361pass back the tree block as the handle. The key for the tree node is the search
362type plus '0' concatenated with the file name. There may be entries in the tree
363with closed files if a lot of files have been opened. */
364
365sprintf(CS keybuffer, "%c%.254s", search_type + '0',
df04890c 366 filename ? filename : US"");
059ec3d9 367
df04890c 368if ((t = tree_search(search_tree, keybuffer)))
059ec3d9 369 {
54a2a2a9 370 if ((c = (search_cache *)t->data.ptr)->handle)
059ec3d9 371 {
42c7f0b4 372 DEBUG(D_lookup) debug_printf_indent(" cached open\n");
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373 store_pool = old_pool;
374 return t;
375 }
42c7f0b4 376 DEBUG(D_lookup) debug_printf_indent(" cached closed\n");
059ec3d9
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377 }
378
379/* Otherwise, we need to open the file or database - each search type has its
380own code, which is now split off into separately compiled modules. Before doing
381this, if the search type is one that uses real files, check on the number that
382we are holding open in the cache. If the limit is reached, close the least
383recently used one. */
384
385if (lk->type == lookup_absfile && open_filecount >= lookup_open_max)
df04890c 386 if (!open_bot)
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387 log_write(0, LOG_MAIN|LOG_PANIC, "too many lookups open, but can't find "
388 "one to close");
389 else
390 {
391 search_cache *c = (search_cache *)(open_bot->data.ptr);
42c7f0b4 392 DEBUG(D_lookup) debug_printf_indent("Too many lookup files open\n closing %s\n",
059ec3d9 393 open_bot->name);
df04890c 394 if ((open_bot = c->up))
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395 ((search_cache *)(open_bot->data.ptr))->down = NULL;
396 else
397 open_top = NULL;
e6d225ae 398 ((lookup_list[c->search_type])->close)(c->handle);
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399 c->handle = NULL;
400 open_filecount--;
401 }
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402
403/* If opening is successful, call the file-checking function if there is one,
404and if all is still well, enter the open database into the tree. */
405
df04890c 406if (!(handle = (lk->open)(filename, &search_error_message)))
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407 {
408 store_pool = old_pool;
409 return NULL;
410 }
411
df04890c
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412if ( lk->check
413 && !lk->check(handle, filename, modemask, owners, owngroups,
414 &search_error_message))
059ec3d9
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415 {
416 lk->close(handle);
417 store_pool = old_pool;
418 return NULL;
419 }
420
421/* If this is a search type that uses real files, keep count. */
422
423if (lk->type == lookup_absfile) open_filecount++;
424
425/* If we found a previously opened entry in the tree, re-use it; otherwise
426insert a new entry. On re-use, leave any cached lookup data and the lookup
427count alone. */
428
df04890c 429if (!t)
059ec3d9 430 {
f3ebb786
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431 t = store_get(sizeof(tree_node) + Ustrlen(keybuffer), FALSE);
432 t->data.ptr = c = store_get(sizeof(search_cache), FALSE);
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433 c->item_cache = NULL;
434 Ustrcpy(t->name, keybuffer);
435 tree_insertnode(&search_tree, t);
436 }
437else c = t->data.ptr;
438
439c->handle = handle;
440c->search_type = search_type;
441c->up = c->down = NULL;
442
443store_pool = old_pool;
444return t;
445}
446
447
448
449
450
451/*************************************************
452* Internal function: Find one item in database *
453*************************************************/
454
455/* The answer is always put into dynamic store. The last lookup for each handle
456is cached.
457
458Arguments:
459 handle the handle from search_open; points to tree node
460 filename the filename that was handed to search_open, or
461 NULL for query-style searches
462 keystring the keystring for single-key+file lookups, or
463 the querystring for query-style lookups
67a57a5a 464 opts type-specific options
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465
466Returns: a pointer to a dynamic string containing the answer,
467 or NULL if the query failed or was deferred; in the
468 latter case, search_find_defer is set TRUE; after an unusual
469 failure, there may be a message in search_error_message.
470*/
471
472static uschar *
67a57a5a
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473internal_search_find(void * handle, const uschar * filename, uschar * keystring,
474 const uschar * opts)
059ec3d9 475{
0488984d
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476tree_node * t = (tree_node *)handle;
477search_cache * c = (search_cache *)(t->data.ptr);
478expiring_data * e = NULL; /* compiler quietening */
479uschar * data = NULL;
059ec3d9
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480int search_type = t->name[0] - '0';
481int old_pool = store_pool;
482
483/* Lookups that return DEFER may not always set an error message. So that
484the callers don't have to test for NULL, set an empty string. */
485
486search_error_message = US"";
8768d548 487f.search_find_defer = FALSE;
059ec3d9 488
42c7f0b4 489DEBUG(D_lookup) debug_printf_indent("internal_search_find: file=\"%s\"\n "
67a57a5a
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490 "type=%s key=\"%s\" opts=%s%s%s\n", filename,
491 lookup_list[search_type]->name, keystring,
492 opts ? "\"" : "", opts, opts ? "\"" : "");
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493
494/* Insurance. If the keystring is empty, just fail. */
495
496if (keystring[0] == 0) return NULL;
497
498/* Use the special store pool for search data */
499
500store_pool = POOL_SEARCH;
501
502/* Look up the data for the key, unless it is already in the cache for this
503file. No need to check c->item_cache for NULL, tree_search will do so. */
504
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505if ( (t = tree_search(c->item_cache, keystring))
506 && (!(e = t->data.ptr)->expiry || e->expiry > time(NULL))
a5dc727a 507 && (!opts && !e->opts || opts && e->opts && Ustrcmp(opts, e->opts) == 0)
14b3c5bc
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508 )
509 { /* Data was in the cache already; set the pointer from the tree node */
7d8d08c4 510 data = e->data.ptr;
42c7f0b4 511 DEBUG(D_lookup) debug_printf_indent("cached data used for lookup of %s%s%s\n",
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512 keystring,
513 filename ? US"\n in " : US"", filename ? filename : US"");
514 }
515else
059ec3d9 516 {
14b3c5bc 517 uint do_cache = UINT_MAX;
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518 int keylength = Ustrlen(keystring);
519
520 DEBUG(D_lookup)
521 {
a5dc727a 522 if (t)
1950cf85
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523 debug_printf_indent("cached data found but %s; ",
524 e->expiry && e->expiry <= time(NULL) ? "out-of-date" : "wrong opts");
42c7f0b4 525 debug_printf_indent("%s lookup required for %s%s%s\n",
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526 filename ? US"file" : US"database",
527 keystring,
528 filename ? US"\n in " : US"", filename ? filename : US"");
059ec3d9
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529 }
530
531 /* Call the code for the different kinds of search. DEFER is handled
532 like FAIL, except that search_find_defer is set so the caller can
533 distinguish if necessary. */
534
e6d225ae 535 if (lookup_list[search_type]->find(c->handle, filename, keystring, keylength,
67a57a5a 536 &data, &search_error_message, &do_cache, opts) == DEFER)
8768d548 537 f.search_find_defer = TRUE;
059ec3d9
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538
539 /* A record that has been found is now in data, which is either NULL
540 or points to a bit of dynamic store. Cache the result of the lookup if
541 caching is permitted. Lookups can disable caching, when they did something
542 that changes their data. The mysql and pgsql lookups do this when an
543 UPDATE/INSERT query was executed. */
544
545 else if (do_cache)
546 {
1950cf85 547 if (!t) /* No existing entry. Create new one. */
14b3c5bc 548 {
92beef8b 549 int len = keylength + 1;
f3ebb786 550 e = store_get(sizeof(expiring_data) + sizeof(tree_node) + len, is_tainted(keystring));
98b98887 551 t = (tree_node *)(e+1);
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552 memcpy(t->name, keystring, len);
553 t->data.ptr = e;
554 tree_insertnode(&c->item_cache, t);
555 }
92beef8b
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556 /* Else previous, out-of-date cache entry. Update with the */
557 /* new result and forget the old one */
558 e->expiry = do_cache == UINT_MAX ? 0 : time(NULL)+do_cache;
1950cf85 559 e->opts = opts ? string_copy(opts) : NULL;
92beef8b 560 e->data.ptr = data;
059ec3d9
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561 }
562
563 /* If caching was disabled, empty the cache tree. We just set the cache
564 pointer to NULL here, because we cannot release the store at this stage. */
565
566 else
567 {
42c7f0b4 568 DEBUG(D_lookup) debug_printf_indent("lookup forced cache cleanup\n");
1950cf85 569 c->item_cache = NULL; /* forget all lookups on this connection */
059ec3d9
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570 }
571 }
572
059ec3d9
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573DEBUG(D_lookup)
574 {
14b3c5bc 575 if (data)
42c7f0b4 576 debug_printf_indent("lookup yielded: %s\n", data);
8768d548 577 else if (f.search_find_defer)
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578 debug_printf_indent("lookup deferred: %s\n", search_error_message);
579 else debug_printf_indent("lookup failed\n");
059ec3d9
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580 }
581
582/* Return it in new dynamic store in the regular pool */
583
584store_pool = old_pool;
14b3c5bc 585return data ? string_copy(data) : NULL;
059ec3d9
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586}
587
588
589
590
591/*************************************************
592* Find one item in database, possibly wildcarded *
593*************************************************/
594
595/* This function calls the internal function above; once only if there
596is no partial matching, but repeatedly when partial matching is requested.
597
598Arguments:
599 handle the handle from search_open
600 filename the filename that was handed to search_open, or
601 NULL for query-style searches
602 keystring the keystring for single-key+file lookups, or
603 the querystring for query-style lookups
604 partial -1 means no partial matching;
605 otherwise it's the minimum number of components;
606 affix the affix string for partial matching
607 affixlen the length of the affix string
608 starflags SEARCH_STAR and SEARCH_STARAT flags
609 expand_setup pointer to offset for setting up expansion strings;
610 don't do any if < 0
67a57a5a 611 opts type-specific options
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612
613Returns: a pointer to a dynamic string containing the answer,
614 or NULL if the query failed or was deferred; in the
615 latter case, search_find_defer is set TRUE
616*/
617
618uschar *
d447dbd1
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619search_find(void * handle, const uschar * filename, uschar * keystring,
620 int partial, const uschar * affix, int affixlen, int starflags,
67a57a5a 621 int * expand_setup, const uschar * opts)
059ec3d9
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622{
623tree_node *t = (tree_node *)handle;
624BOOL set_null_wild = FALSE;
625uschar *yield;
626
627DEBUG(D_lookup)
628 {
629 if (partial < 0) affixlen = 99; /* So that "NULL" prints */
42c7f0b4 630 debug_printf_indent("search_find: file=\"%s\"\n key=\"%s\" "
67a57a5a
JH
631 "partial=%d affix=%.*s starflags=%x opts=%s%s%s\n",
632 filename ? filename : US"NULL",
633 keystring, partial, affixlen, affix, starflags,
634 opts ? "\"" : "", opts, opts ? "\"" : "");
635
059ec3d9
PH
636 }
637
638/* Arrange to put this database at the top of the LRU chain if it is a type
639that opens real files. */
640
df04890c
JH
641if ( open_top != (tree_node *)handle
642 && lookup_list[t->name[0]-'0']->type == lookup_absfile)
059ec3d9
PH
643 {
644 search_cache *c = (search_cache *)(t->data.ptr);
645 tree_node *up = c->up;
646 tree_node *down = c->down;
647
648 /* Cut it out of the list. A newly opened file will a NULL up pointer.
649 Otherwise there will be a non-NULL up pointer, since we checked above that
650 this block isn't already at the top of the list. */
651
df04890c 652 if (up)
059ec3d9
PH
653 {
654 ((search_cache *)(up->data.ptr))->down = down;
df04890c 655 if (down)
059ec3d9 656 ((search_cache *)(down->data.ptr))->up = up;
df04890c
JH
657 else
658 open_bot = up;
059ec3d9
PH
659 }
660
661 /* Now put it at the head of the list. */
662
663 c->up = NULL;
664 c->down = open_top;
df04890c
JH
665 if (!open_top) open_bot = t;
666 else ((search_cache *)(open_top->data.ptr))->up = t;
059ec3d9
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667 open_top = t;
668 }
669
670DEBUG(D_lookup)
671 {
42c7f0b4
JH
672 debug_printf_indent("LRU list:\n");
673 for (tree_node *t = open_top; t; )
059ec3d9
PH
674 {
675 search_cache *c = (search_cache *)(t->data.ptr);
42c7f0b4
JH
676 debug_printf_indent(" %s\n", t->name);
677 if (t == open_bot) debug_printf_indent(" End\n");
059ec3d9
PH
678 t = c->down;
679 }
680 }
681
682/* First of all, try to match the key string verbatim. If matched a complete
683entry but could have been partial, flag to set up variables. */
684
67a57a5a 685yield = internal_search_find(handle, filename, keystring, opts);
8768d548 686if (f.search_find_defer) return NULL;
df04890c
JH
687
688if (yield) { if (partial >= 0) set_null_wild = TRUE; }
059ec3d9
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689
690/* Not matched a complete entry; handle partial lookups, but only if the full
691search didn't defer. Don't use string_sprintf() to construct the initial key,
692just in case the original key is too long for the string_sprintf() buffer (it
693*has* happened!). The case of a zero-length affix has to be treated specially.
694*/
695
696else if (partial >= 0)
697 {
698 int len = Ustrlen(keystring);
699 uschar *keystring2;
700
701 /* Try with the affix on the front, except for a zero-length affix */
702
703 if (affixlen == 0) keystring2 = keystring; else
704 {
f3ebb786
JH
705 keystring2 = store_get(len + affixlen + 1,
706 is_tainted(keystring) || is_tainted(affix));
059ec3d9
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707 Ustrncpy(keystring2, affix, affixlen);
708 Ustrcpy(keystring2 + affixlen, keystring);
42c7f0b4 709 DEBUG(D_lookup) debug_printf_indent("trying partial match %s\n", keystring2);
67a57a5a 710 yield = internal_search_find(handle, filename, keystring2, opts);
8768d548 711 if (f.search_find_defer) return NULL;
059ec3d9
PH
712 }
713
714 /* The key in its entirety did not match a wild entry; try chopping off
715 leading components. */
716
717 if (yield == NULL)
718 {
719 int dotcount = 0;
720 uschar *keystring3 = keystring2 + affixlen;
721 uschar *s = keystring3;
722 while (*s != 0) if (*s++ == '.') dotcount++;
723
724 while (dotcount-- >= partial)
725 {
726 while (*keystring3 != 0 && *keystring3 != '.') keystring3++;
727
728 /* If we get right to the end of the string (which will be the last time
729 through this loop), we've failed if the affix is null. Otherwise do one
730 last lookup for the affix itself, but if it is longer than 1 character,
731 remove the last character if it is ".". */
732
733 if (*keystring3 == 0)
734 {
735 if (affixlen < 1) break;
736 if (affixlen > 1 && affix[affixlen-1] == '.') affixlen--;
737 Ustrncpy(keystring2, affix, affixlen);
738 keystring2[affixlen] = 0;
739 keystring3 = keystring2;
740 }
741 else
742 {
743 keystring3 -= affixlen - 1;
744 if (affixlen > 0) Ustrncpy(keystring3, affix, affixlen);
745 }
746
42c7f0b4 747 DEBUG(D_lookup) debug_printf_indent("trying partial match %s\n", keystring3);
67a57a5a 748 yield = internal_search_find(handle, filename, keystring3, opts);
8768d548 749 if (f.search_find_defer) return NULL;
df04890c 750 if (yield)
059ec3d9
PH
751 {
752 /* First variable is the wild part; second is the fixed part. Take care
753 to get it right when keystring3 is just "*". */
754
df04890c 755 if (expand_setup && *expand_setup >= 0)
059ec3d9
PH
756 {
757 int fixedlength = Ustrlen(keystring3) - affixlen;
758 int wildlength = Ustrlen(keystring) - fixedlength - 1;
759 *expand_setup += 1;
760 expand_nstring[*expand_setup] = keystring;
761 expand_nlength[*expand_setup] = wildlength;
762 *expand_setup += 1;
763 expand_nstring[*expand_setup] = keystring + wildlength + 1;
764 expand_nlength[*expand_setup] = (fixedlength < 0)? 0 : fixedlength;
765 }
766 break;
767 }
768 keystring3 += affixlen;
769 }
770 }
771
772 else set_null_wild = TRUE; /* Matched a wild entry without any wild part */
773 }
774
775/* If nothing has been matched, but the option to look for "*@" is set, try
4c04137d 776replacing everything to the left of @ by *. After a match, the wild part
059ec3d9
PH
777is set to the string to the left of the @. */
778
df04890c 779if (!yield && starflags & SEARCH_STARAT)
059ec3d9
PH
780 {
781 uschar *atat = Ustrrchr(keystring, '@');
782 if (atat != NULL && atat > keystring)
783 {
784 int savechar;
785 savechar = *(--atat);
786 *atat = '*';
787
42c7f0b4 788 DEBUG(D_lookup) debug_printf_indent("trying default match %s\n", atat);
67a57a5a 789 yield = internal_search_find(handle, filename, atat, opts);
059ec3d9 790 *atat = savechar;
8768d548 791 if (f.search_find_defer) return NULL;
059ec3d9 792
df04890c 793 if (yield && expand_setup && *expand_setup >= 0)
059ec3d9
PH
794 {
795 *expand_setup += 1;
796 expand_nstring[*expand_setup] = keystring;
797 expand_nlength[*expand_setup] = atat - keystring + 1;
798 *expand_setup += 1;
799 expand_nstring[*expand_setup] = keystring;
800 expand_nlength[*expand_setup] = 0;
801 }
802 }
803 }
804
805/* If we still haven't matched anything, and the option to look for "*" is set,
806try that. If we do match, the first variable (the wild part) is the whole key,
807and the second is empty. */
808
df04890c 809if (!yield && starflags & (SEARCH_STAR|SEARCH_STARAT))
059ec3d9 810 {
42c7f0b4 811 DEBUG(D_lookup) debug_printf_indent("trying to match *\n");
67a57a5a 812 yield = internal_search_find(handle, filename, US"*", opts);
df04890c 813 if (yield && expand_setup && *expand_setup >= 0)
059ec3d9
PH
814 {
815 *expand_setup += 1;
816 expand_nstring[*expand_setup] = keystring;
817 expand_nlength[*expand_setup] = Ustrlen(keystring);
818 *expand_setup += 1;
819 expand_nstring[*expand_setup] = keystring;
820 expand_nlength[*expand_setup] = 0;
821 }
822 }
823
824/* If this was a potentially partial lookup, and we matched either a
825complete non-wild domain entry, or we matched a wild-carded entry without
826chopping off any of the domain components, set up the expansion variables
827(if required) so that the first one is empty, and the second one is the
828fixed part of the domain. The set_null_wild flag is set only when yield is not
829NULL. */
830
df04890c 831if (set_null_wild && expand_setup && *expand_setup >= 0)
059ec3d9
PH
832 {
833 *expand_setup += 1;
834 expand_nstring[*expand_setup] = keystring;
835 expand_nlength[*expand_setup] = 0;
836 *expand_setup += 1;
837 expand_nstring[*expand_setup] = keystring;
838 expand_nlength[*expand_setup] = Ustrlen(keystring);
839 }
840
841return yield;
842}
843
844/* End of search.c */