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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.
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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");
151 RDEBUG2("Merging cached control list:");
154 rdebug_pair_list(L_DBG_LVL_2, request, c->control);
157 pairadd(&request->config_items, paircopy(request, c->control));
160 if (c->packet && request->packet) {
161 RDEBUG2("Merging cached request list:");
164 rdebug_pair_list(L_DBG_LVL_2, request, c->packet);
167 pairadd(&request->packet->vps,
168 paircopy(request->packet, c->packet));
171 if (c->reply && request->reply) {
172 RDEBUG2("Merging cached reply list:");
175 rdebug_pair_list(L_DBG_LVL_2, request, c->reply);
178 pairadd(&request->reply->vps,
179 paircopy(request->reply, c->reply));
183 vp = paircreate(request->packet, PW_CACHE_ENTRY_HITS, 0);
184 rad_assert(vp != NULL);
186 vp->vp_integer = c->hits;
188 pairadd(&request->packet->vps, vp);
194 * Find a cached entry.
196 static rlm_cache_entry_t *cache_find(rlm_cache_t *inst, REQUEST *request,
200 rlm_cache_entry_t *c, my_c;
204 * Look at the expiry heap.
206 c = fr_heap_peek(inst->heap);
208 rad_assert(rbtree_num_elements(inst->cache) == 0);
213 * If it's time to expire an old entry, do so now.
215 if (c->expires < request->timestamp) {
216 fr_heap_extract(inst->heap, c);
217 rbtree_deletebydata(inst->cache, c);
221 * Is there an entry for this key?
224 c = rbtree_finddata(inst->cache, &my_c);
228 * Yes, but it expired, OR the "forget all" epoch has
229 * passed. Delete it, and pretend it doesn't exist.
231 if ((c->expires < request->timestamp) ||
232 (c->created < inst->epoch)) {
234 RDEBUG("Removing expired entry");
236 fr_heap_extract(inst->heap, c);
237 rbtree_deletebydata(inst->cache, c);
242 RDEBUG("Found entry for \"%s\"", key);
245 * Update the expiry time based on the TTL.
246 * A TTL of 0 means "delete from the cache".
247 * A TTL < 0 means "delete from the cache and recreate the entry".
249 vp = pairfind(request->config_items, PW_CACHE_TTL, 0, TAG_ANY);
251 if (vp->vp_signed <= 0) goto delete;
254 c->expires = request->timestamp + ttl;
255 RDEBUG("Adding %d to the TTL", ttl);
263 /** Callback for map_to_request
265 * Simplifies merging VALUE_PAIRs into the current request.
267 static int _cache_add(VALUE_PAIR **out, REQUEST *request, UNUSED value_pair_map_t const *map, void *ctx)
271 vp = talloc_get_type_abort(ctx, VALUE_PAIR);
272 /* map_to_request will reparent */
273 *out = paircopy(request, vp);
275 if (!*out) return -1;
280 * Add an entry to the cache.
282 static rlm_cache_entry_t *cache_add(rlm_cache_t *inst, REQUEST *request, char const *key)
285 VALUE_PAIR *vp, *to_cache;
286 vp_cursor_t src_list, cached_request, cached_reply, cached_control;
290 value_pair_map_t const *map;
292 rlm_cache_entry_t *c;
294 if (rbtree_num_elements(inst->cache) >= inst->max_entries) {
295 RDEBUG("Cache is full: %d entries", inst->max_entries);
300 * TTL of 0 means "don't cache this entry"
302 vp = pairfind(request->config_items, PW_CACHE_TTL, 0, TAG_ANY);
303 if (vp && (vp->vp_signed == 0)) return NULL;
305 c = talloc_zero(NULL, rlm_cache_entry_t);
306 c->key = talloc_typed_strdup(c, key);
307 c->created = c->expires = request->timestamp;
310 * Use per-entry TTL if > 0, or globally defined one.
312 ttl = vp && (vp->vp_signed > 0) ? vp->vp_integer : inst->ttl;
315 RDEBUG("Creating entry for \"%s\"", key);
318 * Check to see if we need to merge the entry into the request
320 vp = pairfind(request->config_items, PW_CACHE_MERGE, 0, TAG_ANY);
321 if (vp && (vp->vp_integer == 0)) {
323 RDEBUG2("Told not to merge new entry into request");
326 fr_cursor_init(&cached_request, &c->packet);
327 fr_cursor_init(&cached_reply, &c->reply);
328 fr_cursor_init(&cached_control, &c->control);
330 for (map = inst->maps; map != NULL; map = map->next) {
331 bool do_merge = merge;
333 rad_assert(map->lhs && map->rhs);
335 if (map_to_vp(&to_cache, request, map, NULL) < 0) {
336 RDEBUG("Skipping %s", map->rhs->name);
341 * Merge attributes into the current request if:
342 * - Map specifies an xlat'd string.
343 * - Map specifies a literal string.
344 * - Map specifies an exec.
345 * - Map src and dst lists differ.
346 * - Map src and dst attributes differ
348 * Unless Cache-Merge = no
350 if (do_merge) switch (map->rhs->type) {
351 case TMPL_TYPE_LITERAL:
357 if (map->rhs->tmpl_list == map->lhs->tmpl_list) do_merge = false;
361 rad_assert(map->lhs->type == TMPL_TYPE_ATTR);
362 if (map->rhs->tmpl_da == map->lhs->tmpl_da) do_merge = false;
370 * Reparent the VPs map_to_vp may return multiple.
372 for (vp = fr_cursor_init(&src_list, &to_cache);
374 vp = fr_cursor_next(&src_list)) {
378 * Prevent people from accidentally caching
379 * cache control attributes.
381 if (map->rhs->type == TMPL_TYPE_LIST) switch (vp->da->attr) {
383 case PW_CACHE_STATUS_ONLY:
384 case PW_CACHE_READ_ONLY:
386 case PW_CACHE_ENTRY_HITS:
387 RDEBUG2("Skipping %s", vp->da->name);
394 if (debug_flag) map_debug_log(request, map, vp);
395 (void) talloc_steal(c, vp);
399 switch (map->lhs->tmpl_list) {
400 case PAIR_LIST_REQUEST:
401 fr_cursor_insert(&cached_request, vp);
404 case PAIR_LIST_REPLY:
405 fr_cursor_insert(&cached_reply, vp);
408 case PAIR_LIST_CONTROL:
409 fr_cursor_insert(&cached_control, vp);
413 rad_assert(0); /* should have been caught by validation */
416 if (do_merge && map_dst_valid(request, map)) {
417 /* There's no reason for this to fail (we checked the dst was valid) */
418 RDEBUG2("Adding to request:");
419 if (map_to_request(request, map, _cache_add, vp) < 0) rad_assert(0);
424 if (!rbtree_insert(inst->cache, c)) {
425 REDEBUG("FAILED adding entry for key %s", key);
430 if (!fr_heap_insert(inst->heap, c)) {
431 REDEBUG("FAILED adding entry for key %s", key);
432 rbtree_deletebydata(inst->cache, c);
436 RDEBUG("Inserted entry, TTL %d seconds", ttl);
441 /** Verify that a map in the cache section makes sense
444 static int cache_verify(value_pair_map_t *map, UNUSED void *ctx)
446 if (modcall_fixup_update(map, ctx) < 0) return -1;
448 if ((map->lhs->type != TMPL_TYPE_ATTR) &&
449 (map->lhs->type != TMPL_TYPE_LIST)) {
450 cf_log_err(map->ci, "Left operand must be an attribute ref or a list");
454 switch (map->rhs->type) {
456 cf_log_err(map->ci, "Exec values are not allowed");
459 * Only =, :=, += and -= operators are supported for
462 case TMPL_TYPE_LITERAL:
473 cf_log_err(map->ci, "Operator \"%s\" not allowed for %s values",
474 fr_int2str(fr_tokens, map->op, "<INVALID>"),
475 fr_int2str(tmpl_types, map->rhs->type, "<INVALID>"));
486 * Allow single attribute values to be retrieved from the cache.
488 static ssize_t cache_xlat(void *instance, REQUEST *request,
489 char const *fmt, char *out, size_t freespace)
491 rlm_cache_entry_t *c;
492 rlm_cache_t *inst = instance;
493 VALUE_PAIR *vp, *vps;
495 DICT_ATTR const *target;
500 list = radius_list_name(&p, PAIR_LIST_REQUEST);
502 target = dict_attrbyname(p);
504 REDEBUG("Unknown attribute \"%s\"", p);
508 PTHREAD_MUTEX_LOCK(&inst->cache_mutex);
509 c = cache_find(inst, request, fmt);
512 RDEBUG("No cache entry for key \"%s\"", fmt);
518 case PAIR_LIST_REQUEST:
522 case PAIR_LIST_REPLY:
526 case PAIR_LIST_CONTROL:
530 case PAIR_LIST_UNKNOWN:
531 PTHREAD_MUTEX_UNLOCK(&inst->cache_mutex);
532 REDEBUG("Unknown list qualifier in \"%s\"", fmt);
536 PTHREAD_MUTEX_UNLOCK(&inst->cache_mutex);
537 REDEBUG("Unsupported list \"%s\"",
538 fr_int2str(pair_lists, list, "<UNKNOWN>"));
542 vp = pairfind(vps, target->attr, target->vendor, TAG_ANY);
544 RDEBUG("No instance of this attribute has been cached");
549 len = vp_prints_value(out, freespace, vp, 0);
550 if (is_truncated(len, freespace)) {
551 PTHREAD_MUTEX_UNLOCK(&inst->cache_mutex);
552 REDEBUG("Insufficient buffer space to write cached value");
556 PTHREAD_MUTEX_UNLOCK(&inst->cache_mutex);
562 * Only free memory we allocated. The strings allocated via
563 * cf_section_parse() do not need to be freed.
565 static int mod_detach(void *instance)
567 rlm_cache_t *inst = instance;
569 talloc_free(inst->maps);
571 fr_heap_delete(inst->heap);
572 rbtree_free(inst->cache);
574 #ifdef HAVE_PTHREAD_H
575 pthread_mutex_destroy(&inst->cache_mutex);
582 * Instantiate the module.
584 static int mod_instantiate(CONF_SECTION *conf, void *instance)
586 rlm_cache_t *inst = instance;
590 inst->xlat_name = cf_section_name2(conf);
591 if (!inst->xlat_name) {
592 inst->xlat_name = cf_section_name1(conf);
596 * Register the cache xlat function
598 xlat_register(inst->xlat_name, cache_xlat, NULL, inst);
600 rad_assert(inst->key && *inst->key);
602 if (inst->ttl == 0) {
603 cf_log_err_cs(conf, "Must set 'ttl' to non-zero");
607 if (inst->epoch != 0) {
608 cf_log_err_cs(conf, "Must not set 'epoch' in the configuration files");
612 #ifdef HAVE_PTHREAD_H
613 if (pthread_mutex_init(&inst->cache_mutex, NULL) < 0) {
614 ERROR("Failed initializing mutex: %s",
624 inst->cache = rbtree_create(NULL, cache_entry_cmp, cache_entry_free, 0);
626 ERROR("Failed to create cache");
629 fr_link_talloc_ctx_free(inst, inst->cache);
632 * The heap of entries to expire.
634 inst->heap = fr_heap_create(cache_heap_cmp,
635 offsetof(rlm_cache_entry_t, offset));
637 ERROR("Failed to create heap for the cache");
642 * Make sure the users don't screw up too badly.
644 if (map_afrom_cs(&inst->maps, cf_section_sub_find(inst->cs, "update"),
645 PAIR_LIST_REQUEST, PAIR_LIST_REQUEST, cache_verify, NULL, MAX_ATTRMAP) < 0) {
650 cf_log_err_cs(inst->cs, "Cache config must contain an update section, and "
651 "that section must not be empty");
660 * Do caching checks. Since we can update ANY VP list, we do
661 * exactly the same thing for all sections (autz / auth / etc.)
663 * If you want to cache something different in different sections,
664 * configure another cache module.
666 static rlm_rcode_t CC_HINT(nonnull) mod_cache_it(void *instance, REQUEST *request)
668 rlm_cache_entry_t *c;
669 rlm_cache_t *inst = instance;
675 if (radius_xlat(buffer, sizeof(buffer), request, inst->key, NULL, NULL) < 0) {
676 return RLM_MODULE_FAIL;
679 PTHREAD_MUTEX_LOCK(&inst->cache_mutex);
680 c = cache_find(inst, request, buffer);
683 * If yes, only return whether we found a valid cache entry
685 vp = pairfind(request->config_items, PW_CACHE_STATUS_ONLY, 0, TAG_ANY);
686 if (vp && vp->vp_integer) {
687 rcode = c ? RLM_MODULE_OK:
693 cache_merge(inst, request, c);
695 rcode = RLM_MODULE_OK;
699 vp = pairfind(request->config_items, PW_CACHE_READ_ONLY, 0, TAG_ANY);
700 if (vp && vp->vp_integer) {
701 rcode = RLM_MODULE_NOTFOUND;
705 c = cache_add(inst, request, buffer);
707 rcode = RLM_MODULE_NOOP;
711 rcode = RLM_MODULE_UPDATED;
714 PTHREAD_MUTEX_UNLOCK(&inst->cache_mutex);
717 * Reset control attributes
719 for (vp = fr_cursor_init(&cursor, &request->config_items);
721 vp = fr_cursor_next(&cursor)) {
722 if (vp->da->vendor == 0) switch (vp->da->attr) {
724 case PW_CACHE_READ_ONLY:
726 vp = fr_cursor_remove(&cursor);
737 * The module name should be the only globally exported symbol.
738 * That is, everything else should be 'static'.
740 * If the module needs to temporarily modify it's instantiation
741 * data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
742 * The server will then take care of ensuring that the module
743 * is single-threaded.
745 module_t rlm_cache = {
751 mod_instantiate, /* instantiation */
752 mod_detach, /* detach */
754 NULL, /* authentication */
755 mod_cache_it, /* authorization */
756 mod_cache_it, /* preaccounting */
757 mod_cache_it, /* accounting */
758 NULL, /* checksimul */
759 mod_cache_it, /* pre-proxy */
760 mod_cache_it, /* post-proxy */
761 mod_cache_it, /* post-auth */