2 * This program is is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License, version 2 if the
4 * License as published by the Free Software Foundation.
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
19 * @brief Cache values and merge them back into future requests.
21 * @copyright 2012-2013 The FreeRADIUS server project
25 #include <freeradius-devel/radiusd.h>
26 #include <freeradius-devel/modules.h>
27 #include <freeradius-devel/modcall.h>
28 #include <freeradius-devel/heap.h>
29 #include <freeradius-devel/rad_assert.h>
32 * Define a structure for our module configuration.
34 * These variables do not need to be in a structure, but it's
35 * a lot cleaner to do so, and a pointer to the structure can
36 * be used as the instance handle.
38 typedef struct rlm_cache_t {
39 char const *xlat_name;
49 value_pair_map_t *maps; //!< Attribute map applied to users
52 pthread_mutex_t cache_mutex;
56 typedef struct rlm_cache_entry_t {
68 #define PTHREAD_MUTEX_LOCK pthread_mutex_lock
69 #define PTHREAD_MUTEX_UNLOCK pthread_mutex_unlock
71 #define PTHREAD_MUTEX_LOCK(_x)
72 #define PTHREAD_MUTEX_UNLOCK(_x)
75 #define MAX_ATTRMAP 128
78 * A mapping of configuration file names to internal variables.
80 * Note that the string is dynamically allocated, so it MUST
81 * be freed. When the configuration file parse re-reads the string,
82 * it free's the old one, and strdup's the new one, placing the pointer
83 * to the strdup'd string into 'config.string'. This gets around
86 static const CONF_PARSER module_config[] = {
87 { "key", FR_CONF_OFFSET(PW_TYPE_STRING | PW_TYPE_REQUIRED | PW_TYPE_XLAT, rlm_cache_t, key), NULL },
88 { "ttl", FR_CONF_OFFSET(PW_TYPE_INTEGER, rlm_cache_t, ttl), "500" },
89 { "max_entries", FR_CONF_OFFSET(PW_TYPE_INTEGER, rlm_cache_t, max_entries), "16384" },
91 /* Should be a type which matches time_t, @fixme before 2038 */
92 { "epoch", FR_CONF_OFFSET(PW_TYPE_SIGNED, rlm_cache_t, epoch), "0" },
93 { "add_stats", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_cache_t, stats), "no" },
95 { NULL, -1, 0, NULL, NULL } /* end the list */
100 * Compare two entries by key. There may only be one entry with
103 static int cache_entry_cmp(void const *one, void const *two)
105 rlm_cache_entry_t const *a = one;
106 rlm_cache_entry_t const *b = two;
108 return strcmp(a->key, b->key);
111 static void cache_entry_free(void *data)
113 rlm_cache_entry_t *c = data;
115 pairfree(&c->control);
116 pairfree(&c->packet);
123 * Compare two entries by expiry time. There may be multiple
124 * entries with the same expiry time.
126 static int cache_heap_cmp(void const *one, void const *two)
128 rlm_cache_entry_t const *a = one;
129 rlm_cache_entry_t const *b = two;
131 if (a->expires < b->expires) return -1;
132 if (a->expires > b->expires) return +1;
138 * Merge a cached entry into a REQUEST.
140 static void CC_HINT(nonnull) cache_merge(rlm_cache_t *inst, REQUEST *request, rlm_cache_entry_t *c)
144 vp = pairfind(request->config_items, PW_CACHE_MERGE, 0, TAG_ANY);
145 if (vp && (vp->vp_integer == 0)) {
146 RDEBUG2("Told not to merge entry into request");
150 RDEBUG2("Merging cache entry into request");
153 RDEBUG2("Merging cached control list");
154 radius_pairmove(request, &request->config_items, paircopy(request, c->control), false);
157 if (c->packet && request->packet) {
158 RDEBUG2("Merging cached request list");
159 radius_pairmove(request, &request->packet->vps, paircopy(request->packet, c->packet), false);
162 if (c->reply && request->reply) {
163 RDEBUG2("Merging cached reply list");
164 radius_pairmove(request, &request->reply->vps, paircopy(request->reply, c->reply), false);
168 rad_assert(request->packet != NULL);
169 vp = pairfind(request->packet->vps, PW_CACHE_ENTRY_HITS, 0, TAG_ANY);
171 vp = paircreate(request->packet, PW_CACHE_ENTRY_HITS, 0);
172 rad_assert(vp != NULL);
173 pairadd(&request->packet->vps, vp);
175 vp->vp_integer = c->hits;
181 * Find a cached entry.
183 static rlm_cache_entry_t *cache_find(rlm_cache_t *inst, REQUEST *request,
187 rlm_cache_entry_t *c, my_c;
191 * Look at the expiry heap.
193 c = fr_heap_peek(inst->heap);
195 rad_assert(rbtree_num_elements(inst->cache) == 0);
200 * If it's time to expire an old entry, do so now.
202 if (c->expires < request->timestamp) {
203 fr_heap_extract(inst->heap, c);
204 rbtree_deletebydata(inst->cache, c);
208 * Is there an entry for this key?
211 c = rbtree_finddata(inst->cache, &my_c);
215 * Yes, but it expired, OR the "forget all" epoch has
216 * passed. Delete it, and pretend it doesn't exist.
218 if ((c->expires < request->timestamp) ||
219 (c->created < inst->epoch)) {
221 RDEBUG("Removing expired entry");
223 fr_heap_extract(inst->heap, c);
224 rbtree_deletebydata(inst->cache, c);
229 RDEBUG("Found entry for \"%s\"", key);
232 * Update the expiry time based on the TTL.
233 * A TTL of 0 means "delete from the cache".
234 * A TTL < 0 means "delete from the cache and recreate the entry".
236 vp = pairfind(request->config_items, PW_CACHE_TTL, 0, TAG_ANY);
238 if (vp->vp_signed <= 0) goto delete;
241 c->expires = request->timestamp + ttl;
242 RDEBUG("Adding %d to the TTL", ttl);
250 /** Callback for map_to_request
252 * Simplifies merging VALUE_PAIRs into the current request.
254 static int _cache_add(VALUE_PAIR **out, REQUEST *request, UNUSED value_pair_map_t const *map, void *ctx)
258 vp = talloc_get_type_abort(ctx, VALUE_PAIR);
259 /* map_to_request will reparent */
260 *out = paircopy(request, vp);
262 if (!*out) return -1;
267 * Add an entry to the cache.
269 static rlm_cache_entry_t *cache_add(rlm_cache_t *inst, REQUEST *request, char const *key)
272 VALUE_PAIR *vp, *to_cache;
273 vp_cursor_t src_list, cached_request, cached_reply, cached_control;
277 value_pair_map_t const *map;
279 rlm_cache_entry_t *c;
281 if (rbtree_num_elements(inst->cache) >= inst->max_entries) {
282 RDEBUG("Cache is full: %d entries", inst->max_entries);
287 * TTL of 0 means "don't cache this entry"
289 vp = pairfind(request->config_items, PW_CACHE_TTL, 0, TAG_ANY);
290 if (vp && (vp->vp_signed == 0)) return NULL;
292 c = talloc_zero(NULL, rlm_cache_entry_t);
293 c->key = talloc_typed_strdup(c, key);
294 c->created = c->expires = request->timestamp;
297 * Use per-entry TTL if > 0, or globally defined one.
299 ttl = vp && (vp->vp_signed > 0) ? vp->vp_integer : inst->ttl;
302 RDEBUG("Creating entry for \"%s\"", key);
305 * Check to see if we need to merge the entry into the request
307 vp = pairfind(request->config_items, PW_CACHE_MERGE, 0, TAG_ANY);
308 if (vp && (vp->vp_integer == 0)) {
310 RDEBUG2("Told not to merge new entry into request");
313 fr_cursor_init(&cached_request, &c->packet);
314 fr_cursor_init(&cached_reply, &c->reply);
315 fr_cursor_init(&cached_control, &c->control);
317 for (map = inst->maps; map != NULL; map = map->next) {
318 bool do_merge = merge;
320 rad_assert(map->lhs && map->rhs);
322 if (map_to_vp(&to_cache, request, map, NULL) < 0) {
323 RDEBUG("Skipping %s", map->rhs->name);
328 * Merge attributes into the current request if:
329 * - Map specifies an xlat'd string.
330 * - Map specifies a literal string.
331 * - Map specifies an exec.
332 * - Map src and dst lists differ.
333 * - Map src and dst attributes differ
335 * Unless Cache-Merge = no
337 if (do_merge) switch (map->rhs->type) {
338 case TMPL_TYPE_LITERAL:
344 if (map->rhs->tmpl_list == map->lhs->tmpl_list) do_merge = false;
348 rad_assert(map->lhs->type == TMPL_TYPE_ATTR);
349 if (map->rhs->tmpl_da == map->lhs->tmpl_da) do_merge = false;
357 * Reparent the VPs map_to_vp may return multiple.
359 for (vp = fr_cursor_init(&src_list, &to_cache);
361 vp = fr_cursor_next(&src_list)) {
365 * Prevent people from accidentally caching
366 * cache control attributes.
368 if (map->rhs->type == TMPL_TYPE_LIST) switch (vp->da->attr) {
370 case PW_CACHE_STATUS_ONLY:
371 case PW_CACHE_READ_ONLY:
373 case PW_CACHE_ENTRY_HITS:
374 RDEBUG2("Skipping %s", vp->da->name);
381 if (debug_flag) map_debug_log(request, map, vp);
382 (void) talloc_steal(c, vp);
386 switch (map->lhs->tmpl_list) {
387 case PAIR_LIST_REQUEST:
388 fr_cursor_insert(&cached_request, vp);
391 case PAIR_LIST_REPLY:
392 fr_cursor_insert(&cached_reply, vp);
395 case PAIR_LIST_CONTROL:
396 fr_cursor_insert(&cached_control, vp);
400 rad_assert(0); /* should have been caught by validation */
403 if (do_merge && map_dst_valid(request, map)) {
404 /* There's no reason for this to fail (we checked the dst was valid) */
405 RDEBUG2("Adding to request:");
406 if (map_to_request(request, map, _cache_add, vp) < 0) rad_assert(0);
411 if (!rbtree_insert(inst->cache, c)) {
412 REDEBUG("FAILED adding entry for key %s", key);
417 if (!fr_heap_insert(inst->heap, c)) {
418 REDEBUG("FAILED adding entry for key %s", key);
419 rbtree_deletebydata(inst->cache, c);
423 RDEBUG("Inserted entry, TTL %d seconds", ttl);
428 /** Verify that a map in the cache section makes sense
431 static int cache_verify(value_pair_map_t *map, UNUSED void *ctx)
433 if (modcall_fixup_update(map, ctx) < 0) return -1;
435 if ((map->lhs->type != TMPL_TYPE_ATTR) &&
436 (map->lhs->type != TMPL_TYPE_LIST)) {
437 cf_log_err(map->ci, "Left operand must be an attribute ref or a list");
441 switch (map->rhs->type) {
443 cf_log_err(map->ci, "Exec values are not allowed");
446 * Only =, :=, += and -= operators are supported for
449 case TMPL_TYPE_LITERAL:
460 cf_log_err(map->ci, "Operator \"%s\" not allowed for %s values",
461 fr_int2str(fr_tokens, map->op, "<INVALID>"),
462 fr_int2str(tmpl_types, map->rhs->type, "<INVALID>"));
473 * Allow single attribute values to be retrieved from the cache.
475 static ssize_t cache_xlat(void *instance, REQUEST *request,
476 char const *fmt, char *out, size_t freespace)
478 rlm_cache_entry_t *c;
479 rlm_cache_t *inst = instance;
480 VALUE_PAIR *vp, *vps;
482 DICT_ATTR const *target;
487 p += radius_list_name(&list, p, PAIR_LIST_REQUEST);
488 if (list == PAIR_LIST_UNKNOWN) {
489 REDEBUG("Unknown list qualifier in \"%s\"", fmt);
493 target = dict_attrbyname(p);
495 REDEBUG("Unknown attribute \"%s\"", p);
499 PTHREAD_MUTEX_LOCK(&inst->cache_mutex);
500 c = cache_find(inst, request, fmt);
503 RDEBUG("No cache entry for key \"%s\"", fmt);
509 case PAIR_LIST_REQUEST:
513 case PAIR_LIST_REPLY:
517 case PAIR_LIST_CONTROL:
522 PTHREAD_MUTEX_UNLOCK(&inst->cache_mutex);
523 REDEBUG("Unsupported list \"%s\"",
524 fr_int2str(pair_lists, list, "<UNKNOWN>"));
528 vp = pairfind(vps, target->attr, target->vendor, TAG_ANY);
530 RDEBUG("No instance of this attribute has been cached");
535 len = vp_prints_value(out, freespace, vp, 0);
536 if (is_truncated(len, freespace)) {
537 PTHREAD_MUTEX_UNLOCK(&inst->cache_mutex);
538 REDEBUG("Insufficient buffer space to write cached value");
542 PTHREAD_MUTEX_UNLOCK(&inst->cache_mutex);
548 * Only free memory we allocated. The strings allocated via
549 * cf_section_parse() do not need to be freed.
551 static int mod_detach(void *instance)
553 rlm_cache_t *inst = instance;
555 talloc_free(inst->maps);
557 fr_heap_delete(inst->heap);
558 rbtree_free(inst->cache);
560 #ifdef HAVE_PTHREAD_H
561 pthread_mutex_destroy(&inst->cache_mutex);
568 * Instantiate the module.
570 static int mod_instantiate(CONF_SECTION *conf, void *instance)
572 rlm_cache_t *inst = instance;
576 inst->xlat_name = cf_section_name2(conf);
577 if (!inst->xlat_name) inst->xlat_name = cf_section_name1(conf);
580 * Register the cache xlat function
582 xlat_register(inst->xlat_name, cache_xlat, NULL, inst);
584 rad_assert(inst->key && *inst->key);
586 if (inst->ttl == 0) {
587 cf_log_err_cs(conf, "Must set 'ttl' to non-zero");
591 if (inst->epoch != 0) {
592 cf_log_err_cs(conf, "Must not set 'epoch' in the configuration files");
596 #ifdef HAVE_PTHREAD_H
597 if (pthread_mutex_init(&inst->cache_mutex, NULL) < 0) {
598 ERROR("Failed initializing mutex: %s",
608 inst->cache = rbtree_create(NULL, cache_entry_cmp, cache_entry_free, 0);
610 ERROR("Failed to create cache");
613 fr_link_talloc_ctx_free(inst, inst->cache);
616 * The heap of entries to expire.
618 inst->heap = fr_heap_create(cache_heap_cmp,
619 offsetof(rlm_cache_entry_t, offset));
621 ERROR("Failed to create heap for the cache");
626 * Make sure the users don't screw up too badly.
628 if (map_afrom_cs(&inst->maps, cf_section_sub_find(inst->cs, "update"),
629 PAIR_LIST_REQUEST, PAIR_LIST_REQUEST, cache_verify, NULL, MAX_ATTRMAP) < 0) {
634 cf_log_err_cs(inst->cs, "Cache config must contain an update section, and "
635 "that section must not be empty");
644 * Do caching checks. Since we can update ANY VP list, we do
645 * exactly the same thing for all sections (autz / auth / etc.)
647 * If you want to cache something different in different sections,
648 * configure another cache module.
650 static rlm_rcode_t CC_HINT(nonnull) mod_cache_it(void *instance, REQUEST *request)
652 rlm_cache_entry_t *c;
653 rlm_cache_t *inst = instance;
659 if (radius_xlat(buffer, sizeof(buffer), request, inst->key, NULL, NULL) < 0) {
660 return RLM_MODULE_FAIL;
663 PTHREAD_MUTEX_LOCK(&inst->cache_mutex);
664 c = cache_find(inst, request, buffer);
667 * If yes, only return whether we found a valid cache entry
669 vp = pairfind(request->config_items, PW_CACHE_STATUS_ONLY, 0, TAG_ANY);
670 if (vp && vp->vp_integer) {
671 rcode = c ? RLM_MODULE_OK:
677 cache_merge(inst, request, c);
679 rcode = RLM_MODULE_OK;
683 vp = pairfind(request->config_items, PW_CACHE_READ_ONLY, 0, TAG_ANY);
684 if (vp && vp->vp_integer) {
685 rcode = RLM_MODULE_NOTFOUND;
689 c = cache_add(inst, request, buffer);
691 rcode = RLM_MODULE_NOOP;
695 rcode = RLM_MODULE_UPDATED;
698 PTHREAD_MUTEX_UNLOCK(&inst->cache_mutex);
701 * Reset control attributes
703 for (vp = fr_cursor_init(&cursor, &request->config_items);
705 vp = fr_cursor_next(&cursor)) {
706 if (vp->da->vendor == 0) switch (vp->da->attr) {
708 case PW_CACHE_READ_ONLY:
710 vp = fr_cursor_remove(&cursor);
721 * The module name should be the only globally exported symbol.
722 * That is, everything else should be 'static'.
724 * If the module needs to temporarily modify it's instantiation
725 * data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
726 * The server will then take care of ensuring that the module
727 * is single-threaded.
729 module_t rlm_cache = {
735 mod_instantiate, /* instantiation */
736 mod_detach, /* detach */
738 NULL, /* authentication */
739 mod_cache_it, /* authorization */
740 mod_cache_it, /* preaccounting */
741 mod_cache_it, /* accounting */
742 NULL, /* checksimul */
743 mod_cache_it, /* pre-proxy */
744 mod_cache_it, /* post-proxy */
745 mod_cache_it, /* post-auth */