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 as published by
4 * the Free Software Foundation; either version 2 of the License, or (at
5 * your option) any later version.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
20 * @brief Cache values and merge them back into future requests.
22 * @copyright 2012-2014 The FreeRADIUS server project
26 #include <freeradius-devel/radiusd.h>
27 #include <freeradius-devel/modules.h>
28 #include <freeradius-devel/modpriv.h>
29 #include <freeradius-devel/modcall.h>
30 #include <freeradius-devel/rad_assert.h>
32 #include "rlm_cache.h"
35 * A mapping of configuration file names to internal variables.
37 * Note that the string is dynamically allocated, so it MUST
38 * be freed. When the configuration file parse re-reads the string,
39 * it free's the old one, and strdup's the new one, placing the pointer
40 * to the strdup'd string into 'config.string'. This gets around
43 static const CONF_PARSER module_config[] = {
44 { "driver", FR_CONF_OFFSET(PW_TYPE_STRING, rlm_cache_t, driver_name), "rlm_cache_rbtree" },
45 { "key", FR_CONF_OFFSET(PW_TYPE_STRING | PW_TYPE_REQUIRED | PW_TYPE_XLAT, rlm_cache_t, key), NULL },
46 { "ttl", FR_CONF_OFFSET(PW_TYPE_INTEGER, rlm_cache_t, ttl), "500" },
47 { "max_entries", FR_CONF_OFFSET(PW_TYPE_INTEGER, rlm_cache_t, max_entries), "0" },
49 /* Should be a type which matches time_t, @fixme before 2038 */
50 { "epoch", FR_CONF_OFFSET(PW_TYPE_SIGNED, rlm_cache_t, epoch), "0" },
51 { "add_stats", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, rlm_cache_t, stats), "no" },
52 CONF_PARSER_TERMINATOR
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;
65 if (!handle || !*handle) 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 || !*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 = fr_pair_find_by_num(request->config, 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 rad_assert(request->packet != NULL);
131 rdebug_pair_list(L_DBG_LVL_2, request, c->packet, "&request:");
132 radius_pairmove(request, &request->packet->vps, fr_pair_list_copy(request->packet, c->packet), false);
135 if (c->reply && request->reply) {
136 rdebug_pair_list(L_DBG_LVL_2, request, c->reply, "&reply:");
137 radius_pairmove(request, &request->reply->vps, fr_pair_list_copy(request->reply, c->reply), false);
141 rdebug_pair_list(L_DBG_LVL_2, request, c->control, "&control:");
142 radius_pairmove(request, &request->config, fr_pair_list_copy(request, c->control), false);
146 rdebug_pair_list(L_DBG_LVL_2, request, c->state, "&session-state:");
148 fr_pair_list_mcopy_by_num(request->state_ctx, &request->state, &c->state, 0, 0, TAG_ANY);
152 rad_assert(request->packet != NULL);
153 vp = fr_pair_find_by_num(request->packet->vps, PW_CACHE_ENTRY_HITS, 0, TAG_ANY);
155 vp = fr_pair_afrom_num(request->packet, PW_CACHE_ENTRY_HITS, 0);
156 rad_assert(vp != NULL);
157 fr_pair_add(&request->packet->vps, vp);
159 vp->vp_integer = c->hits;
164 /** Find a cached entry.
166 * @return RLM_MODULE_OK on success, RLM_MODULE_FAIL on failure, RLM_MODULE_NOTFOUND if notfound.
168 static rlm_rcode_t cache_find(rlm_cache_entry_t **out, rlm_cache_t *inst, REQUEST *request,
169 rlm_cache_handle_t **handle, char const *key)
173 rlm_cache_entry_t *c;
178 ret = inst->module->find(&c, inst, request, handle, key);
180 case CACHE_RECONNECT:
181 RDEBUG("Reconnecting...");
182 if (cache_reconnect(inst, request, handle) == 0) continue;
183 return RLM_MODULE_FAIL;
189 RDEBUG("No cache entry found for \"%s\"", key);
190 return RLM_MODULE_NOTFOUND;
194 return RLM_MODULE_FAIL;
202 * Yes, but it expired, OR the "forget all" epoch has
203 * passed. Delete it, and pretend it doesn't exist.
205 if ((c->expires < request->timestamp) || (c->created < inst->epoch)) {
206 RDEBUG("Removing expired entry");
208 inst->module->expire(inst, request, handle, c);
209 cache_free(inst, &c);
210 return RLM_MODULE_NOTFOUND; /* Couldn't find a non-expired entry */
213 RDEBUG("Found entry for \"%s\"", key);
218 return RLM_MODULE_OK;
221 /** Expire a cache entry (removing it from the datastore)
224 static void cache_expire(rlm_cache_t *inst, REQUEST *request, rlm_cache_handle_t **handle, rlm_cache_entry_t **c)
228 for (;;) switch (inst->module->expire(inst, request, handle, *c)) {
229 case CACHE_RECONNECT:
230 if (cache_reconnect(inst, request, handle) == 0) continue;
240 /** Create and insert a cache entry.
242 * @return RLM_MODULE_OK on success, RLM_MODULE_UPDATED if we merged the cache entry and RLM_MODULE_FAIL on failure.
244 static rlm_rcode_t cache_insert(rlm_cache_t *inst, REQUEST *request, rlm_cache_handle_t **handle,
245 char const *key, int ttl)
247 VALUE_PAIR *vp, *to_cache;
248 vp_cursor_t src_list, packet, reply, control, state;
253 rlm_cache_entry_t *c;
255 if ((inst->max_entries > 0) && inst->module->count &&
256 (inst->module->count(inst, request, handle) > inst->max_entries)) {
257 RWDEBUG("Cache is full: %d entries", inst->max_entries);
258 return RLM_MODULE_FAIL;
261 c = cache_alloc(inst, request);
262 if (!c) return RLM_MODULE_FAIL;
264 c->key = talloc_typed_strdup(c, key);
265 c->created = c->expires = request->timestamp;
268 RDEBUG("Creating new cache entry");
270 fr_cursor_init(&packet, &c->packet);
271 fr_cursor_init(&reply, &c->reply);
272 fr_cursor_init(&control, &c->control);
273 fr_cursor_init(&state, &c->state);
275 for (map = inst->maps; map != NULL; map = map->next) {
276 rad_assert(map->lhs && map->rhs);
278 if (map_to_vp(c, &to_cache, request, map, NULL) < 0) {
279 RDEBUG("Skipping %s", map->rhs->name);
283 for (vp = fr_cursor_init(&src_list, &to_cache);
285 vp = fr_cursor_next(&src_list)) {
289 * Prevent people from accidentally caching
290 * cache control attributes.
292 if (map->rhs->type == TMPL_TYPE_LIST) switch (vp->da->attr) {
294 case PW_CACHE_STATUS_ONLY:
295 case PW_CACHE_READ_ONLY:
297 case PW_CACHE_ENTRY_HITS:
298 RDEBUG2("Skipping %s", vp->da->name);
306 if (RDEBUG_ENABLED2) map_debug_log(request, map, vp);
311 switch (map->lhs->tmpl_list) {
312 case PAIR_LIST_REQUEST:
313 fr_cursor_insert(&packet, vp);
316 case PAIR_LIST_REPLY:
317 fr_cursor_insert(&reply, vp);
320 case PAIR_LIST_CONTROL:
321 fr_cursor_insert(&control, vp);
324 case PAIR_LIST_STATE:
325 fr_cursor_insert(&state, vp);
329 rad_assert(0); /* should have been caught by validation */
335 * Check to see if we need to merge the entry into the request
337 vp = fr_pair_find_by_num(request->config, PW_CACHE_MERGE, 0, TAG_ANY);
338 if (vp && (vp->vp_integer == 0)) merge = false;
340 if (merge) cache_merge(inst, request, c);
345 ret = inst->module->insert(inst, request, handle, c);
347 case CACHE_RECONNECT:
348 if (cache_reconnect(inst, request, handle) == 0) continue;
349 return RLM_MODULE_FAIL;
352 RDEBUG("Committed entry, TTL %d seconds", ttl);
353 cache_free(inst, &c);
354 return RLM_MODULE_UPDATED;
357 talloc_free(c); /* Failed insertion - use talloc_free not the driver free */
358 return RLM_MODULE_FAIL;
363 /** Verify that a map in the cache section makes sense
366 static int cache_verify(vp_map_t *map, void *ctx)
368 if (modcall_fixup_update(map, ctx) < 0) return -1;
370 if ((map->lhs->type != TMPL_TYPE_ATTR) &&
371 (map->lhs->type != TMPL_TYPE_LIST)) {
372 cf_log_err(map->ci, "Destination must be an attribute ref or a list");
376 switch (map->lhs->tmpl_list) {
377 case PAIR_LIST_REQUEST:
378 case PAIR_LIST_REPLY:
379 case PAIR_LIST_CONTROL:
380 case PAIR_LIST_STATE:
384 cf_log_err(map->ci, "Destination list must be one of request, reply, control or session-state");
388 if (map->lhs->tmpl_request != REQUEST_CURRENT) {
389 cf_log_err(map->ci, "Cached attributes can only be inserted into the current request");
393 switch (map->rhs->type) {
395 cf_log_err(map->ci, "Exec values are not allowed");
398 * Only =, :=, += and -= operators are supported for
401 case TMPL_TYPE_LITERAL:
412 cf_log_err(map->ci, "Operator \"%s\" not allowed for %s values",
413 fr_int2str(fr_tokens, map->op, "<INVALID>"),
414 fr_int2str(tmpl_names, map->rhs->type, "<INVALID>"));
425 * Do caching checks. Since we can update ANY VP list, we do
426 * exactly the same thing for all sections (autz / auth / etc.)
428 * If you want to cache something different in different sections,
429 * configure another cache module.
431 static rlm_rcode_t CC_HINT(nonnull) mod_cache_it(void *instance, REQUEST *request)
433 rlm_cache_entry_t *c;
434 rlm_cache_t *inst = instance;
436 rlm_cache_handle_t *handle;
445 if (radius_xlat(buffer, sizeof(buffer), request, inst->key, NULL, NULL) < 0) return RLM_MODULE_FAIL;
447 if (buffer[0] == '\0') {
448 REDEBUG("Zero length key string is invalid");
449 return RLM_MODULE_INVALID;
452 if (cache_acquire(&handle, inst, request) < 0) return RLM_MODULE_FAIL;
454 rcode = cache_find(&c, inst, request, &handle, buffer);
455 if (rcode == RLM_MODULE_FAIL) goto finish;
459 * If Cache-Status-Only == yes, only return whether we found a
462 vp = fr_pair_find_by_num(request->config, PW_CACHE_STATUS_ONLY, 0, TAG_ANY);
463 if (vp && vp->vp_integer) {
464 rcode = c ? RLM_MODULE_OK:
470 * Update the expiry time based on the TTL.
471 * A TTL of 0 means "delete from the cache".
472 * A TTL < 0 means "delete from the cache and recreate the entry".
474 vp = fr_pair_find_by_num(request->config, PW_CACHE_TTL, 0, TAG_ANY);
475 if (vp) ttl = vp->vp_signed;
478 * If there's no existing cache entry, go and create a new one.
481 if (ttl <= 0) ttl = inst->ttl;
486 * Expire the entry if requested to do so
490 cache_expire(inst, request, &handle, &c);
491 RDEBUG("Forcing expiry of entry");
492 rcode = RLM_MODULE_OK;
497 RDEBUG("Forcing expiry of existing entry");
498 cache_expire(inst, request, &handle, &c);
502 c->expires = request->timestamp + ttl;
503 RDEBUG("Setting TTL to %d", ttl);
507 * Cache entry was still valid, so we merge it into the request
508 * and return. No need to add a new entry.
510 cache_merge(inst, request, c);
511 rcode = RLM_MODULE_OK;
517 * If Cache-Read-Only == yes, then we only allow already cached entries
518 * to be merged into the request
520 vp = fr_pair_find_by_num(request->config, PW_CACHE_READ_ONLY, 0, TAG_ANY);
521 if (vp && vp->vp_integer) {
522 rcode = RLM_MODULE_NOTFOUND;
527 * Create a new entry.
529 rcode = cache_insert(inst, request, &handle, buffer, ttl);
533 cache_free(inst, &c);
534 cache_release(inst, request, &handle);
537 * Clear control attributes
539 for (vp = fr_cursor_init(&cursor, &request->config);
541 vp = fr_cursor_next(&cursor)) {
542 if (vp->da->vendor == 0) switch (vp->da->attr) {
544 case PW_CACHE_STATUS_ONLY:
545 case PW_CACHE_READ_ONLY:
547 vp = fr_cursor_remove(&cursor);
556 static ssize_t CC_HINT(nonnull) cache_xlat(void *instance, REQUEST *request,
557 char const *fmt, char *out, size_t freespace);
560 * Allow single attribute values to be retrieved from the cache.
562 static ssize_t cache_xlat(void *instance, REQUEST *request,
563 char const *fmt, char *out, size_t freespace)
565 rlm_cache_entry_t *c = NULL;
566 rlm_cache_t *inst = instance;
567 rlm_cache_handle_t *handle = NULL;
569 VALUE_PAIR *vp, *vps;
571 DICT_ATTR const *target;
576 p += radius_list_name(&list, p, PAIR_LIST_REQUEST);
577 if (list == PAIR_LIST_UNKNOWN) {
578 REDEBUG("Unknown list qualifier in \"%s\"", fmt);
583 target = dict_attrbyname(p);
585 REDEBUG("Unknown attribute \"%s\"", p);
589 if (cache_acquire(&handle, inst, request) < 0) return -1;
591 switch (cache_find(&c, inst, request, handle, fmt)) {
592 case RLM_MODULE_OK: /* found */
595 case RLM_MODULE_NOTFOUND: /* not found */
604 case PAIR_LIST_REQUEST:
608 case PAIR_LIST_REPLY:
612 case PAIR_LIST_CONTROL:
616 case PAIR_LIST_STATE:
621 REDEBUG("Unsupported list \"%s\"", fr_int2str(pair_lists, list, "<UNKNOWN>"));
626 vp = fr_pair_find_by_num(vps, target->attr, target->vendor, TAG_ANY);
628 RDEBUG("No instance of this attribute has been cached");
633 len = vp_prints_value(out, freespace, vp, 0);
634 if (is_truncated(len, freespace)) {
635 REDEBUG("Insufficient buffer space to write cached value");
641 cache_free(inst, &c);
642 cache_release(inst, request, &handle);
648 * Only free memory we allocated. The strings allocated via
649 * cf_section_parse() do not need to be freed.
651 static int mod_detach(void *instance)
653 rlm_cache_t *inst = instance;
655 talloc_free(inst->maps);
658 * We need to explicitly free all children, so if the driver
659 * parented any memory off the instance, their destructors
660 * run before we unload the bytecode for them.
662 * If we don't do this, we get a SEGV deep inside the talloc code
663 * when it tries to call a destructor that no longer exists.
665 talloc_free_children(inst);
668 * Decrements the reference count. The driver object won't be unloaded
669 * until all instances of rlm_cache that use it have been destroyed.
671 if (inst->handle) dlclose(inst->handle);
677 static int mod_bootstrap(CONF_SECTION *conf, void *instance)
679 rlm_cache_t *inst = instance;
683 inst->name = cf_section_name2(conf);
684 if (!inst->name) inst->name = cf_section_name1(conf);
687 * Register the cache xlat function
689 xlat_register(inst->name, cache_xlat, NULL, inst);
696 * Instantiate the module.
698 static int mod_instantiate(CONF_SECTION *conf, void *instance)
700 rlm_cache_t *inst = instance;
701 CONF_SECTION *update;
706 * Sanity check for crazy people.
708 if (strncmp(inst->driver_name, "rlm_cache_", 8) != 0) {
709 cf_log_err_cs(conf, "\"%s\" is NOT an Cache driver!", inst->driver_name);
714 * Load the appropriate driver for our database
716 inst->handle = fr_dlopenext(inst->driver_name);
718 cf_log_err_cs(conf, "Could not link driver %s: %s", inst->driver_name, dlerror());
719 cf_log_err_cs(conf, "Make sure it (and all its dependent libraries!) are in the search path"
720 " of your system's ld");
724 inst->module = (cache_module_t *) dlsym(inst->handle, inst->driver_name);
726 cf_log_err_cs(conf, "Could not link symbol %s: %s", inst->driver_name, dlerror());
730 DEBUG("rlm_cache (%s): Driver %s (module %s) loaded and linked", inst->name,
731 inst->driver_name, inst->module->name);
734 * Non optional fields and callbacks
736 rad_assert(inst->module->name);
737 rad_assert(inst->module->find);
738 rad_assert(inst->module->insert);
739 rad_assert(inst->module->expire);
741 if (inst->module->instantiate) {
745 name = strrchr(inst->driver_name, '_');
747 name = inst->driver_name;
752 cs = cf_section_sub_find(conf, name);
754 cs = cf_section_alloc(conf, name, NULL);
759 * It's up to the driver to register a destructor (using talloc)
761 * Should write its instance data in inst->driver,
762 * and parent it off of inst.
764 if (inst->module->instantiate(cs, inst) < 0) return -1;
767 rad_assert(inst->key && *inst->key);
769 if (inst->ttl == 0) {
770 cf_log_err_cs(conf, "Must set 'ttl' to non-zero");
774 if (inst->epoch != 0) {
775 cf_log_err_cs(conf, "Must not set 'epoch' in the configuration files");
779 update = cf_section_sub_find(inst->cs, "update");
781 cf_log_err_cs(conf, "Must have an 'update' section in order to cache anything.");
786 * Make sure the users don't screw up too badly.
788 if (map_afrom_cs(&inst->maps, update,
789 PAIR_LIST_REQUEST, PAIR_LIST_REQUEST, cache_verify, NULL, MAX_ATTRMAP) < 0) {
794 cf_log_err_cs(inst->cs, "Cache config must contain an update section, and "
795 "that section must not be empty");
803 * The module name should be the only globally exported symbol.
804 * That is, everything else should be 'static'.
806 * If the module needs to temporarily modify it's instantiation
807 * data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
808 * The server will then take care of ensuring that the module
809 * is single-threaded.
811 extern module_t rlm_cache;
812 module_t rlm_cache = {
813 .magic = RLM_MODULE_INIT,
815 .inst_size = sizeof(rlm_cache_t),
816 .config = module_config,
817 .bootstrap = mod_bootstrap,
818 .instantiate = mod_instantiate,
819 .detach = mod_detach,
821 [MOD_AUTHORIZE] = mod_cache_it,
822 [MOD_PREACCT] = mod_cache_it,
823 [MOD_ACCOUNTING] = mod_cache_it,
824 [MOD_PRE_PROXY] = mod_cache_it,
825 [MOD_POST_PROXY] = mod_cache_it,
826 [MOD_POST_AUTH] = mod_cache_it