rlm_cache_redis.c

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/*
 *   This program is is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or (at
 *   your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: d5ad02d98725df5611c7d6fdc5b7d7727500418b $
 * @file rlm_cache_redis.c
 * @brief redis based cache.
 *
 * @copyright 2015 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 */
#define LOG_PREFIX "cache - redis"
 
#include <freeradius-devel/server/base.h>
#include <freeradius-devel/util/debug.h>
#include <freeradius-devel/util/value.h>
 
#include "../../rlm_cache.h"
#include <freeradius-devel/redis/base.h>
#include <freeradius-devel/redis/cluster.h>
static conf_parser_t driver_config[] = {
        REDIS_COMMON_CONFIG,
        CONF_PARSER_TERMINATOR
};
 
typedef struct {
        fr_redis_conf_t         conf;           //!< Connection parameters for the Redis server.
                                                //!< Must be first field in this struct.
 
        tmpl_t          *created_attr;  //!< LHS of the Cache-Created map.
        tmpl_t          *expires_attr;  //!< LHS of the Cache-Expires map.
 
        fr_redis_cluster_t      *cluster;
} rlm_cache_redis_t;
 
static fr_dict_t const *dict_freeradius;
 
extern fr_dict_autoload_t rlm_cache_redis_dict[];
fr_dict_autoload_t rlm_cache_redis_dict[] = {
        { .out = &dict_freeradius, .proto = "freeradius" },
        { NULL }
};
 
static fr_dict_attr_t const *attr_cache_created;
static fr_dict_attr_t const *attr_cache_expires;
 
extern fr_dict_attr_autoload_t rlm_cache_redis_dict_attr[];
fr_dict_attr_autoload_t rlm_cache_redis_dict_attr[] = {
        { .out = &attr_cache_created, .name = "Cache-Created", .type = FR_TYPE_DATE, .dict = &dict_freeradius },
        { .out = &attr_cache_expires, .name = "Cache-Expires", .type = FR_TYPE_DATE, .dict = &dict_freeradius },
        { NULL }
};
 
/** Create a new rlm_cache_redis instance
 *
 * @param[in] mctx              Data required for instantiation.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int mod_instantiate(module_inst_ctx_t const *mctx)
{
        rlm_cache_redis_t               *driver = talloc_get_type_abort(mctx->mi->data, rlm_cache_redis_t);
        char                            buffer[256];
 
        buffer[0] = '\0';
 
        if (cf_section_rules_push(mctx->mi->conf, driver_config) < 0) return -1;
        if (cf_section_parse(driver, driver, mctx->mi->conf) < 0) return -1;
 
        snprintf(buffer, sizeof(buffer), "rlm_cache (%s)", mctx->mi->parent->name);
 
        driver->cluster = fr_redis_cluster_alloc(driver, mctx->mi->conf, &driver->conf, true,
                                                 buffer, "modules.cache.pool", NULL);
        if (!driver->cluster) {
                ERROR("Cluster failure");
                return -1;
        }
 
        /*
         *      These never change, so do it once on instantiation
         */
        if (tmpl_afrom_attr_str(driver, NULL, &driver->created_attr, "&Cache-Created", NULL) <= 0) {
                ERROR("Cache-Created attribute not defined");
                return -1;
        }
 
        if (tmpl_afrom_attr_str(driver, NULL, &driver->expires_attr, "&Cache-Expires", NULL) <= 0) {
                ERROR("Cache-Expires attribute not defined");
                return -1;
        }
 
        return 0;
}
 
static int mod_load(void)
{
        fr_redis_version_print();
        return 0;
}
 
static void cache_entry_free(rlm_cache_entry_t *c)
{
        talloc_free(c);
}
 
/** Locate a cache entry in redis
 *
 * @copydetails cache_entry_find_t
 */
static cache_status_t cache_entry_find(rlm_cache_entry_t **out,
                                       UNUSED rlm_cache_config_t const *config, void *instance,
                                       request_t *request, UNUSED void *handle, fr_value_box_t const *key)
{
        rlm_cache_redis_t               *driver = instance;
        size_t                          i;
 
        fr_redis_cluster_state_t        state;
        fr_redis_conn_t                 *conn;
        fr_redis_rcode_t                status;
        redisReply                      *reply = NULL;
        int                             s_ret;
 
        map_list_t                      head;
#ifdef HAVE_TALLOC_ZERO_POOLED_OBJECT
        size_t                          pool_size = 0;
#endif
        rlm_cache_entry_t               *c;
 
        map_list_init(&head);
        for (s_ret = fr_redis_cluster_state_init(&state, &conn, driver->cluster, request, (uint8_t const *)key->vb_strvalue, key->vb_length, false);
             s_ret == REDIS_RCODE_TRY_AGAIN;    /* Continue */
             s_ret = fr_redis_cluster_state_next(&state, &conn, driver->cluster, request, status, &reply)) {
                /*
                 *      Grab all the data for this hash, should return an array
                 *      of alternating keys/values which we then convert into maps.
                 */
                RDEBUG3("LRANGE %pV 0 -1", key);
                reply = redisCommand(conn->handle, "LRANGE %b 0 -1", key->vb_strvalue, key->vb_length);
                status = fr_redis_command_status(conn, reply);
        }
        if (s_ret != REDIS_RCODE_SUCCESS) {
                RERROR("Failed retrieving entry for key \"%pV\"", key);
 
        error:
                fr_redis_reply_free(&reply);
                return CACHE_ERROR;
        }
 
        if (!fr_cond_assert(reply)) goto error;
 
        if (reply->type != REDIS_REPLY_ARRAY) {
                REDEBUG("Bad result type, expected array, got %s",
                        fr_table_str_by_value(redis_reply_types, reply->type, "<UNKNOWN>"));
                goto error;
        }
 
        RDEBUG3("Entry contains %zu elements", reply->elements);
 
        if (reply->elements == 0) {
                fr_redis_reply_free(&reply);
                return CACHE_MISS;
        }
 
        if (reply->elements % 3) {
                REDEBUG("Invalid number of reply elements (%zu).  "
                        "Reply must contain triplets of keys operators and values",
                        reply->elements);
                goto error;
        }
 
#ifdef HAVE_TALLOC_ZERO_POOLED_OBJECT
        /*
         *      We can get a pretty good idea of the required size of the pool
         */
        for (i = 0; i < reply->elements; i += 3) {
                pool_size += sizeof(map_t) + (sizeof(tmpl_t) * 2);
                if (reply->element[i]->type == REDIS_REPLY_STRING) pool_size += reply->element[i]->len + 1;
        }
 
        /*
         *      reply->elements gives us the number of chunks, as the maps are triplets, and there
         *      are three chunks per map
         */
 
        c = talloc_zero_pooled_object(NULL, rlm_cache_entry_t, reply->elements, pool_size);
#else
        c = talloc_zero(NULL, rlm_cache_entry_t);
#endif
        map_list_init(&c->maps);
        /*
         *      Convert the key/value pairs back into maps
         */
        for (i = 0; i < reply->elements; i += 3) {
                if (fr_redis_reply_to_map(c, &head, request,
                                          reply->element[i], reply->element[i + 1], reply->element[i + 2]) < 0) {
                        talloc_free(c);
                        fr_redis_reply_free(&reply);
                        return CACHE_ERROR;
                }
        }
        fr_redis_reply_free(&reply);
 
        /*
         *      Pull out the cache created date
         */
        if (tmpl_attr_tail_da(map_list_head(&head)->lhs) == attr_cache_created) {
                map_t *map;
 
                c->created = tmpl_value(map_list_head(&head)->rhs)->vb_date;
 
                map = map_list_pop_head(&head);
                talloc_free(map);
        }
 
        /*
         *      Pull out the cache expires date
         */
        if (tmpl_attr_tail_da(map_list_head(&head)->lhs) == attr_cache_expires) {
                map_t *map;
 
                c->expires = tmpl_value(map_list_head(&head)->rhs)->vb_date;
 
                map = map_list_pop_head(&head);
                talloc_free(map);
        }
 
        if (unlikely(fr_value_box_copy(c, &c->key, key) < 0)) goto error;
 
        map_list_move(&c->maps, &head);
        *out = c;
 
        return CACHE_OK;
}
 
 
/** Insert a new entry into the data store
 *
 * @copydetails cache_entry_insert_t
 */
static cache_status_t cache_entry_insert(UNUSED rlm_cache_config_t const *config, void *instance,
                                         request_t *request, UNUSED void *handle, const rlm_cache_entry_t *c)
{
        rlm_cache_redis_t       *driver = instance;
        TALLOC_CTX              *pool;
 
        map_t                   *map = NULL;
 
        fr_redis_conn_t         *conn;
        fr_redis_cluster_state_t        state;
        fr_redis_rcode_t        status;
        redisReply              *reply = NULL;
        int                     s_ret;
 
        static char const       command[] = "RPUSH";
        char const              **argv;
        size_t                  *argv_len;
        char const              **argv_p;
        size_t                  *argv_len_p;
 
        unsigned int            pipelined = 0;  /* How many commands pending in the pipeline */
        redisReply              *replies[5];    /* Should have the same number of elements as pipelined commands */
        size_t                  reply_cnt = 0, i;
 
        int                     cnt;
 
        tmpl_t          expires_value;
        map_t           expires = {
                                        .op     = T_OP_SET,
                                        .lhs    = driver->expires_attr,
                                        .rhs    = &expires_value,
                                };
 
        tmpl_t          created_value;
        map_t           created = {
                                        .op     = T_OP_SET,
                                        .lhs    = driver->created_attr,
                                        .rhs    = &created_value,
                                };
 
        /*
         *      Encode the entry created date
         */
        tmpl_init_shallow(&created_value, TMPL_TYPE_DATA, T_BARE_WORD, "<TEMP>", 6, NULL);
        fr_value_box_init(&created_value.data.literal, FR_TYPE_DATE, NULL, true);
        tmpl_value(&created_value)->vb_date = c->created;
 
        /*
         *      Encode the entry expiry time
         *
         *      Although Redis objects expire on their own, we still need this
         *      to ignore entries that were created before the last epoch.
         */
        tmpl_init_shallow(&expires_value, TMPL_TYPE_DATA, T_BARE_WORD, "<TEMP>", 6, NULL);
        fr_value_box_init(&expires_value.data.literal, FR_TYPE_DATE, NULL, true);
        tmpl_value(&expires_value)->vb_date = c->expires;
 
        cnt = map_list_num_elements(&c->maps) + 2;
 
        /*
         *      The majority of serialized entries should be under 1k.
         *
         * @todo We should really calculate this using some sort of moving average.
         */
        pool = talloc_pool(request, 1024);
        if (!pool) return CACHE_ERROR;
 
        argv_p = argv = talloc_array(pool, char const *, (cnt * 3) + 2);        /* pair = 3 + cmd + key */
        argv_len_p = argv_len = talloc_array(pool, size_t, (cnt * 3) + 2);      /* pair = 3 + cmd + key */
 
        *argv_p++ = command;
        *argv_len_p++ = sizeof(command) - 1;
 
        *argv_p++ = (char const *)c->key.vb_strvalue;
        *argv_len_p++ = c->key.vb_length;
 
        /*
         *      Add the maps to the command string in reverse order
         */
        if (fr_redis_tuple_from_map(pool, argv_p, argv_len_p, &created) < 0) {
                REDEBUG("Failed encoding map as Redis K/V pair");
                talloc_free(pool);
                return CACHE_ERROR;
        }
        argv_p += 3;
        argv_len_p += 3;
        if (fr_redis_tuple_from_map(pool, argv_p, argv_len_p, &expires) < 0) {
                REDEBUG("Failed encoding map as Redis K/V pair");
                talloc_free(pool);
                return CACHE_ERROR;
        }
        argv_p += 3;
        argv_len_p += 3;
        while ((map = map_list_next(&c->maps, map))) {
                if (fr_redis_tuple_from_map(pool, argv_p, argv_len_p, map) < 0) {
                        REDEBUG("Failed encoding map as Redis K/V pair");
                        talloc_free(pool);
                        return CACHE_ERROR;
                }
                argv_p += 3;
                argv_len_p += 3;
        }
 
        RDEBUG3("Pipelining commands");
 
        for (s_ret = fr_redis_cluster_state_init(&state, &conn, driver->cluster, request, (uint8_t const *)c->key.vb_strvalue, c->key.vb_length, false);
             s_ret == REDIS_RCODE_TRY_AGAIN;    /* Continue */
             s_ret = fr_redis_cluster_state_next(&state, &conn, driver->cluster, request, status, &reply)) {
                /*
                 *      Start the transaction, as we need to set an expiry time too.
                 */
                if (fr_unix_time_ispos(c->expires)) {
                        RDEBUG3("MULTI");
                        if (redisAppendCommand(conn->handle, "MULTI") != REDIS_OK) {
                        append_error:
                                REXDENT();
                                RERROR("Failed appending Redis command to output buffer: %s", conn->handle->errstr);
                                talloc_free(pool);
                                return CACHE_ERROR;
                        }
                        pipelined++;
                }
 
                RDEBUG3("DEL \"%pV\"", &c->key);
 
                if (redisAppendCommand(conn->handle, "DEL %b", (uint8_t const *)c->key.vb_strvalue, c->key.vb_length) != REDIS_OK) goto append_error;
                pipelined++;
 
                if (RDEBUG_ENABLED3) {
                        RDEBUG3("argv command");
                        RINDENT();
                        for (i = 0; i < talloc_array_length(argv); i++) {
                                RDEBUG3("%pV", fr_box_strvalue_len(argv[i], argv_len[i]));
                        }
                        REXDENT();
                }
                redisAppendCommandArgv(conn->handle, talloc_array_length(argv), argv, argv_len);
                pipelined++;
 
                /*
                 *      Set the expiry time and close out the transaction.
                 */
                if (fr_unix_time_ispos(c->expires)) {
                        RDEBUG3("EXPIREAT \"%pV\" %" PRIu64,
                                &c->key,
                                fr_unix_time_to_sec(c->expires));
                        if (redisAppendCommand(conn->handle, "EXPIREAT %b %" PRIu64, (uint8_t const *)c->key.vb_strvalue, (size_t)c->key.vb_length,
                                               fr_unix_time_to_sec(c->expires)) != REDIS_OK) goto append_error;
                        pipelined++;
                        RDEBUG3("EXEC");
                        if (redisAppendCommand(conn->handle, "EXEC") != REDIS_OK) goto append_error;
                        pipelined++;
                }
 
                reply_cnt = fr_redis_pipeline_result(&pipelined, &status,
                                                     replies, NUM_ELEMENTS(replies),
                                                     conn);
                reply = replies[0];
        }
        talloc_free(pool);
 
        if (s_ret != REDIS_RCODE_SUCCESS) {
                RPERROR("Failed inserting entry");
                return CACHE_ERROR;
        }
 
        RDEBUG3("Command results");
        RINDENT();
        if (RDEBUG_ENABLED3) for (i = 0; i < reply_cnt; i++) fr_redis_reply_print(L_DBG_LVL_3, replies[i], request, i);
        fr_redis_pipeline_free(replies, reply_cnt);
        REXDENT();
 
        return CACHE_OK;
}
 
/** Call delete the cache entry from redis
 *
 * @copydetails cache_entry_expire_t
 */
static cache_status_t cache_entry_expire(UNUSED rlm_cache_config_t const *config, void *instance,
                                         request_t *request, UNUSED void *handle, fr_value_box_t const *key)
{
        rlm_cache_redis_t               *driver = instance;
        fr_redis_cluster_state_t        state;
        fr_redis_conn_t                 *conn;
        fr_redis_rcode_t                        status;
        redisReply                      *reply = NULL;
        int                             s_ret;
        cache_status_t                  cache_status;
 
        for (s_ret = fr_redis_cluster_state_init(&state, &conn, driver->cluster, request, (uint8_t const *)key->vb_strvalue, key->vb_length, false);
             s_ret == REDIS_RCODE_TRY_AGAIN;    /* Continue */
             s_ret = fr_redis_cluster_state_next(&state, &conn, driver->cluster, request, status, &reply)) {
                reply = redisCommand(conn->handle, "DEL %b", (uint8_t const *)key->vb_strvalue, key->vb_length);
                status = fr_redis_command_status(conn, reply);
        }
 
        if (s_ret != REDIS_RCODE_SUCCESS) {
                RERROR("Failed expiring entry");
        error:
                fr_redis_reply_free(&reply);
                return CACHE_ERROR;
        }
        if (!fr_cond_assert(reply)) goto error;
 
        if (reply->type == REDIS_REPLY_INTEGER) {
                cache_status = CACHE_MISS;
                if (reply->integer) cache_status = CACHE_OK;    /* Affected */
                fr_redis_reply_free(&reply);
                return cache_status;
        }
 
        REDEBUG("Bad result type, expected integer, got %s",
                fr_table_str_by_value(redis_reply_types, reply->type, "<UNKNOWN>"));
        fr_redis_reply_free(&reply);
 
        return CACHE_ERROR;
}
 
extern rlm_cache_driver_t rlm_cache_redis;
rlm_cache_driver_t rlm_cache_redis = {
        .common = {
                .magic          = MODULE_MAGIC_INIT,
                .name           = "cache_redis",
                .onload         = mod_load,
                .instantiate    = mod_instantiate,
                .inst_size      = sizeof(rlm_cache_redis_t),
                .config         = driver_config,
        },
        .free           = cache_entry_free,
        .find           = cache_entry_find,
        .insert         = cache_entry_insert,
        .expire         = cache_entry_expire,
};