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 2012-2014 The FreeRADIUS server project
25 #include <freeradius-devel/radiusd.h>
26 #include <freeradius-devel/modules.h>
27 #include <freeradius-devel/modpriv.h>
28 #include <freeradius-devel/modcall.h>
29 #include <freeradius-devel/rad_assert.h>
31 #include "rlm_cache.h"
34 * A mapping of configuration file names to internal variables.
36 * Note that the string is dynamically allocated, so it MUST
37 * be freed. When the configuration file parse re-reads the string,
38 * it free's the old one, and strdup's the new one, placing the pointer
39 * to the strdup'd string into 'config.string'. This gets around
42 static const CONF_PARSER module_config[] = {
43 { "driver", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_cache_t, driver_name), "rlm_cache_rbtree" },
44 { "key", FR_CONF_OFFSET(PW_TYPE_STRING | PW_TYPE_REQUIRED | PW_TYPE_XLAT, rlm_cache_t, key), NULL },
45 { "ttl", FR_CONF_OFFSET(PW_TYPE_INTEGER, rlm_cache_t, ttl), "500" },
46 { "max_entries", FR_CONF_OFFSET(PW_TYPE_INTEGER, rlm_cache_t, max_entries), "0" },
48 /* Should be a type which matches time_t, @fixme before 2038 */
49 { "epoch", FR_CONF_OFFSET(PW_TYPE_SIGNED, rlm_cache_t, epoch), "0" },
50 { "add_stats", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_cache_t, stats), "no" },
52 { NULL, -1, 0, NULL, NULL } /* end the list */
55 static int cache_acquire(rlm_cache_handle_t **out, rlm_cache_t *inst, REQUEST *request)
57 if (!inst->module->acquire) return 0;
59 return inst->module->acquire(out, inst, request);
62 static void cache_release(rlm_cache_t *inst, REQUEST *request, rlm_cache_handle_t **handle)
64 if (!inst->module->release) return;
67 inst->module->release(inst, request, handle);
70 static int cache_reconnect(rlm_cache_t *inst, REQUEST *request, rlm_cache_handle_t **handle)
72 rad_assert(inst->module->reconnect);
74 return inst->module->reconnect(inst, request, handle);
77 /** Allocate a cache entry
79 * This is used so that drivers may use their own allocation functions
80 * to allocate structures larger than the normal rlm_cache_entry_t.
82 * If the driver doesn't specify a custom allocation function, the cache
83 * entry is talloced in the NULL ctx.
85 static rlm_cache_entry_t *cache_alloc(rlm_cache_t *inst, REQUEST *request)
87 if (inst->module->alloc) return inst->module->alloc(inst, request);
89 return talloc_zero(NULL, rlm_cache_entry_t);
92 /** Free memory associated with a cache entry
94 * This does not necessarily remove the entry from the cache, cache_expire
95 * should be used for that.
97 * This function should be called when an entry that is known to have been
98 * retrieved or inserted into a data store successfully, is no longer needed.
100 * Some drivers (like rlm_cache_rbtree) don't register a free function.
101 * This means that the cache entry never needs to be explicitly freed.
103 * @param c Cache entry to free.
104 * @param inst Module instance.
106 static void cache_free(rlm_cache_t *inst, rlm_cache_entry_t **c)
108 if (!*c || !inst->module->free) return;
110 inst->module->free(*c);
115 * Merge a cached entry into a REQUEST.
117 static void CC_HINT(nonnull) cache_merge(rlm_cache_t *inst, REQUEST *request, rlm_cache_entry_t *c)
121 vp = pairfind(request->config_items, PW_CACHE_MERGE, 0, TAG_ANY);
122 if (vp && (vp->vp_integer == 0)) {
123 RDEBUG2("Told not to merge entry into request");
127 RDEBUG2("Merging cache entry into request");
130 rdebug_pair_list(L_DBG_LVL_2, request, c->control, "&control:");
131 radius_pairmove(request, &request->config_items, paircopy(request, c->control), false);
134 if (c->packet && request->packet) {
135 rdebug_pair_list(L_DBG_LVL_2, request, c->packet, "&request:");
136 radius_pairmove(request, &request->packet->vps, paircopy(request->packet, c->packet), false);
139 if (c->reply && request->reply) {
140 rdebug_pair_list(L_DBG_LVL_2, request, c->reply, "&reply:");
141 radius_pairmove(request, &request->reply->vps, paircopy(request->reply, c->reply), false);
145 rad_assert(request->packet != NULL);
146 vp = pairfind(request->packet->vps, PW_CACHE_ENTRY_HITS, 0, TAG_ANY);
148 vp = paircreate(request->packet, PW_CACHE_ENTRY_HITS, 0);
149 rad_assert(vp != NULL);
150 pairadd(&request->packet->vps, vp);
152 vp->vp_integer = c->hits;
157 /** Find a cached entry.
159 * @return RLM_MODULE_OK on success, RLM_MODULE_FAIL on failure, RLM_MODULE_NOTFOUND if notfound.
161 static rlm_rcode_t cache_find(rlm_cache_entry_t **out, rlm_cache_t *inst, REQUEST *request,
162 rlm_cache_handle_t **handle, char const *key)
166 rlm_cache_entry_t *c;
171 ret = inst->module->find(&c, inst, request, handle, key);
173 case CACHE_RECONNECT:
174 RDEBUG("Reconnecting...");
175 if (cache_reconnect(inst, request, handle) == 0) continue;
176 return RLM_MODULE_FAIL;
182 RDEBUG("No cache entry found for \"%s\"", key);
183 return RLM_MODULE_NOTFOUND;
187 return RLM_MODULE_FAIL;
195 * Yes, but it expired, OR the "forget all" epoch has
196 * passed. Delete it, and pretend it doesn't exist.
198 if ((c->expires < request->timestamp) || (c->created < inst->epoch)) {
199 RDEBUG("Removing expired entry");
201 inst->module->expire(inst, request, handle, c);
202 cache_free(inst, &c);
203 return RLM_MODULE_NOTFOUND; /* Couldn't find a non-expired entry */
206 RDEBUG("Found entry for \"%s\"", key);
211 return RLM_MODULE_OK;
214 /** Expire a cache entry (removing it from the datastore)
217 static void cache_expire(rlm_cache_t *inst, REQUEST *request, rlm_cache_handle_t **handle, rlm_cache_entry_t **c)
221 for (;;) switch (inst->module->expire(inst, request, handle, *c)) {
222 case CACHE_RECONNECT:
223 if (cache_reconnect(inst, request, handle) == 0) continue;
233 /** Create and insert a cache entry.
235 * @return RLM_MODULE_OK on success, RLM_MODULE_UPDATED if we merged the cache entry and RLM_MODULE_FAIL on failure.
237 static rlm_rcode_t cache_insert(rlm_cache_t *inst, REQUEST *request, rlm_cache_handle_t **handle,
238 char const *key, int ttl)
240 VALUE_PAIR *vp, *to_cache;
241 vp_cursor_t src_list, cached_request, cached_reply, cached_control;
243 value_pair_map_t const *map;
246 rlm_cache_entry_t *c;
248 if ((inst->max_entries > 0) && inst->module->count &&
249 (inst->module->count(inst, request, handle) > inst->max_entries)) {
250 RWDEBUG("Cache is full: %d entries", inst->max_entries);
251 return RLM_MODULE_FAIL;
254 c = cache_alloc(inst, request);
255 if (!c) return RLM_MODULE_FAIL;
257 c->key = talloc_typed_strdup(c, key);
258 c->created = c->expires = request->timestamp;
261 RDEBUG("Creating new cache entry");
263 fr_cursor_init(&cached_request, &c->packet);
264 fr_cursor_init(&cached_reply, &c->reply);
265 fr_cursor_init(&cached_control, &c->control);
267 for (map = inst->maps; map != NULL; map = map->next) {
268 rad_assert(map->lhs && map->rhs);
270 if (map_to_vp(&to_cache, request, map, NULL) < 0) {
271 RDEBUG("Skipping %s", map->rhs->name);
276 * Reparent the VPs map_to_vp may return multiple.
278 for (vp = fr_cursor_init(&src_list, &to_cache);
280 vp = fr_cursor_next(&src_list)) {
284 * Prevent people from accidentally caching
285 * cache control attributes.
287 if (map->rhs->type == TMPL_TYPE_LIST) switch (vp->da->attr) {
289 case PW_CACHE_STATUS_ONLY:
290 case PW_CACHE_READ_ONLY:
292 case PW_CACHE_ENTRY_HITS:
293 RDEBUG2("Skipping %s", vp->da->name);
301 if (RDEBUG_ENABLED2) map_debug_log(request, map, vp);
303 (void) talloc_steal(c, vp);
307 switch (map->lhs->tmpl_list) {
308 case PAIR_LIST_REQUEST:
309 fr_cursor_insert(&cached_request, vp);
312 case PAIR_LIST_REPLY:
313 fr_cursor_insert(&cached_reply, vp);
316 case PAIR_LIST_CONTROL:
317 fr_cursor_insert(&cached_control, vp);
321 rad_assert(0); /* should have been caught by validation */
327 * Check to see if we need to merge the entry into the request
329 vp = pairfind(request->config_items, PW_CACHE_MERGE, 0, TAG_ANY);
330 if (vp && (vp->vp_integer > 0)) merge = true;
332 if (merge) cache_merge(inst, request, c);
337 ret = inst->module->insert(inst, request, handle, c);
339 case CACHE_RECONNECT:
340 if (cache_reconnect(inst, request, handle) == 0) continue;
341 return RLM_MODULE_FAIL;
344 RDEBUG("Commited entry, TTL %d seconds", ttl);
345 cache_free(inst, &c);
346 return merge ? RLM_MODULE_UPDATED :
350 talloc_free(c); /* Failed insertion - use talloc_free not the driver free */
351 return RLM_MODULE_FAIL;
356 /** Verify that a map in the cache section makes sense
359 static int cache_verify(value_pair_map_t *map, UNUSED void *ctx)
361 if (modcall_fixup_update(map, ctx) < 0) return -1;
363 if ((map->lhs->type != TMPL_TYPE_ATTR) &&
364 (map->lhs->type != TMPL_TYPE_LIST)) {
365 cf_log_err(map->ci, "Left operand must be an attribute ref or a list");
369 switch (map->rhs->type) {
371 cf_log_err(map->ci, "Exec values are not allowed");
374 * Only =, :=, += and -= operators are supported for
377 case TMPL_TYPE_LITERAL:
388 cf_log_err(map->ci, "Operator \"%s\" not allowed for %s values",
389 fr_int2str(fr_tokens, map->op, "<INVALID>"),
390 fr_int2str(tmpl_types, map->rhs->type, "<INVALID>"));
401 * Do caching checks. Since we can update ANY VP list, we do
402 * exactly the same thing for all sections (autz / auth / etc.)
404 * If you want to cache something different in different sections,
405 * configure another cache module.
407 static rlm_rcode_t CC_HINT(nonnull) mod_cache_it(void *instance, REQUEST *request)
409 rlm_cache_entry_t *c;
410 rlm_cache_t *inst = instance;
412 rlm_cache_handle_t *handle;
421 if (radius_xlat(buffer, sizeof(buffer), request, inst->key, NULL, NULL) < 0) return RLM_MODULE_FAIL;
423 if (buffer[0] == '\0') {
424 REDEBUG("Zero length key string is invalid");
425 return RLM_MODULE_INVALID;
428 if (cache_acquire(&handle, inst, request) < 0) return RLM_MODULE_FAIL;
430 rcode = cache_find(&c, inst, request, &handle, buffer);
431 if (rcode == RLM_MODULE_FAIL) goto finish;
435 * If Cache-Status-Only == yes, only return whether we found a
438 vp = pairfind(request->config_items, PW_CACHE_STATUS_ONLY, 0, TAG_ANY);
439 if (vp && vp->vp_integer) {
440 rcode = c ? RLM_MODULE_OK:
446 * Update the expiry time based on the TTL.
447 * A TTL of 0 means "delete from the cache".
448 * A TTL < 0 means "delete from the cache and recreate the entry".
450 vp = pairfind(request->config_items, PW_CACHE_TTL, 0, TAG_ANY);
451 if (vp) ttl = vp->vp_signed;
454 * If there's no existing cache entry, go and create a new one.
457 if (ttl <= 0) ttl = inst->ttl;
462 * Expire the entry if requested to do so
466 cache_expire(inst, request, &handle, &c);
467 RDEBUG("Forcing expiry of entry");
468 rcode = RLM_MODULE_OK;
473 RDEBUG("Forcing expiry of existing entry");
474 cache_expire(inst, request, &handle, &c);
478 c->expires = request->timestamp + ttl;
479 RDEBUG("Setting TTL to %d", ttl);
483 * Cache entry was still valid, so we merge it into the request
484 * and return. No need to add a new entry.
486 cache_merge(inst, request, c);
487 rcode = RLM_MODULE_UPDATED;
493 * If Cache-Read-Only == yes, then we only allow already cached entries
494 * to be merged into the request
496 vp = pairfind(request->config_items, PW_CACHE_READ_ONLY, 0, TAG_ANY);
497 if (vp && vp->vp_integer) {
498 rcode = RLM_MODULE_NOTFOUND;
503 * Create a new entry.
505 rcode = cache_insert(inst, request, &handle, buffer, ttl);
509 cache_free(inst, &c);
510 cache_release(inst, request, &handle);
513 * Clear control attributes
515 for (vp = fr_cursor_init(&cursor, &request->config_items);
517 vp = fr_cursor_next(&cursor)) {
518 if (vp->da->vendor == 0) switch (vp->da->attr) {
520 case PW_CACHE_STATUS_ONLY:
521 case PW_CACHE_READ_ONLY:
523 vp = fr_cursor_remove(&cursor);
533 * Allow single attribute values to be retrieved from the cache.
535 static ssize_t cache_xlat(void *instance, REQUEST *request,
536 char const *fmt, char *out, size_t freespace)
538 rlm_cache_entry_t *c;
539 rlm_cache_t *inst = instance;
540 rlm_cache_handle_t *handle;
542 VALUE_PAIR *vp, *vps;
544 DICT_ATTR const *target;
549 p += radius_list_name(&list, p, PAIR_LIST_REQUEST);
550 if (list == PAIR_LIST_UNKNOWN) {
551 REDEBUG("Unknown list qualifier in \"%s\"", fmt);
556 target = dict_attrbyname(p);
558 REDEBUG("Unknown attribute \"%s\"", p);
562 if (cache_acquire(&handle, inst, request) < 0) return -1;
564 switch (cache_find(&c, inst, request, handle, fmt)) {
565 case RLM_MODULE_OK: /* found */
568 case RLM_MODULE_NOTFOUND: /* not found */
577 case PAIR_LIST_REQUEST:
581 case PAIR_LIST_REPLY:
585 case PAIR_LIST_CONTROL:
589 case PAIR_LIST_UNKNOWN:
592 REDEBUG("Unsupported list \"%s\"", fr_int2str(pair_lists, list, "<UNKNOWN>"));
597 vp = pairfind(vps, target->attr, target->vendor, TAG_ANY);
599 RDEBUG("No instance of this attribute has been cached");
604 len = vp_prints_value(out, freespace, vp, 0);
605 if (is_truncated(len, freespace)) {
606 REDEBUG("Insufficient buffer space to write cached value");
612 cache_free(inst, &c);
613 cache_release(inst, request, &handle);
619 * Only free memory we allocated. The strings allocated via
620 * cf_section_parse() do not need to be freed.
622 static int mod_detach(void *instance)
624 rlm_cache_t *inst = instance;
626 talloc_free(inst->maps);
629 * We need to explicitly free all children, so if the driver
630 * parented any memory off the instance, their destructors
631 * run before we unload the bytecode for them.
633 * If we don't do this, we get a SEGV deep inside the talloc code
634 * when it tries to call a destructor that no longer exists.
636 talloc_free_children(inst);
639 * Decrements the reference count. The driver object won't be unloaded
640 * until all instances of rlm_cache that use it have been destroyed.
642 if (inst->handle) dlclose(inst->handle);
648 * Instantiate the module.
650 static int mod_instantiate(CONF_SECTION *conf, void *instance)
652 rlm_cache_t *inst = instance;
656 inst->xlat_name = cf_section_name2(conf);
657 if (!inst->xlat_name) inst->xlat_name = cf_section_name1(conf);
660 * Register the cache xlat function
662 xlat_register(inst->xlat_name, cache_xlat, NULL, inst);
665 * Sanity check for crazy people.
667 if (strncmp(inst->driver_name, "rlm_cache_", 8) != 0) {
668 ERROR("%s: \"%s\" is NOT an Cache driver!", inst->xlat_name, inst->driver_name);
673 * Load the appropriate driver for our database
675 inst->handle = lt_dlopenext(inst->driver_name);
677 ERROR("Could not link driver %s: %s", inst->driver_name, dlerror());
678 ERROR("Make sure it (and all its dependent libraries!) are in the search path of your system's ld");
682 inst->module = (cache_module_t *) dlsym(inst->handle, inst->driver_name);
684 ERROR("Could not link symbol %s: %s", inst->driver_name, dlerror());
688 DEBUG3("Driver %s loaded successfully", inst->module->name);
691 * Non optional fields and callbacks
693 rad_assert(inst->module->name);
694 rad_assert(inst->module->find);
695 rad_assert(inst->module->insert);
696 rad_assert(inst->module->expire);
698 if (inst->module->mod_instantiate) {
702 name = strrchr(inst->driver_name, '_');
704 name = inst->driver_name;
709 cs = cf_section_sub_find(conf, name);
711 cs = cf_section_alloc(conf, name, NULL);
716 * It's up to the driver to register a destructor (using talloc)
718 * Should write its instance data in inst->driver,
719 * and parent it off of inst.
721 if (inst->module->mod_instantiate(cs, inst) < 0) return -1;
724 rad_assert(inst->key && *inst->key);
726 if (inst->ttl == 0) {
727 cf_log_err_cs(conf, "Must set 'ttl' to non-zero");
731 if (inst->epoch != 0) {
732 cf_log_err_cs(conf, "Must not set 'epoch' in the configuration files");
737 * Make sure the users don't screw up too badly.
739 if (map_afrom_cs(&inst->maps, cf_section_sub_find(inst->cs, "update"),
740 PAIR_LIST_REQUEST, PAIR_LIST_REQUEST, cache_verify, NULL, MAX_ATTRMAP) < 0) {
745 cf_log_err_cs(inst->cs, "Cache config must contain an update section, and "
746 "that section must not be empty");
754 * The module name should be the only globally exported symbol.
755 * That is, everything else should be 'static'.
757 * If the module needs to temporarily modify it's instantiation
758 * data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
759 * The server will then take care of ensuring that the module
760 * is single-threaded.
762 module_t rlm_cache = {
768 mod_instantiate, /* instantiation */
769 mod_detach, /* detach */
771 NULL, /* authentication */
772 mod_cache_it, /* authorization */
773 mod_cache_it, /* preaccounting */
774 mod_cache_it, /* accounting */
775 NULL, /* checksimul */
776 mod_cache_it, /* pre-proxy */
777 mod_cache_it, /* post-proxy */
778 mod_cache_it, /* post-auth */