rlm_sql_cassandra.c

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/**
 * This is free and unencumbered software released into the public domain.
 *
 * Anyone is free to copy, modify, publish, use, compile, sell, or
 * distribute this software, either in source code form or as a compiled
 * binary, for any purpose, commercial or non-commercial, and by any
 * means.
 *
 * In jurisdictions that recognize copyright laws, the author or authors
 * of this software dedicate any and all copyright interest in the
 * software to the public domain. We make this dedication for the benefit
 * of the public at large and to the detriment of our heirs and
 * successors. We intend this dedication to be an overt act of
 * relinquishment in perpetuity of all present and future rights to this
 * software under copyright law.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
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 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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/**
 * $Id: d544f2fe79d4529d712097c97f868aa476ea3aa1 $
 * @file rlm_sql_cassandra.c
 * @brief Cassandra SQL driver
 *
 * @author Linnaea Von Lavia (le.concorde.4590@gmail.com)
 * @author Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 */
#define LOG_PREFIX "sql - cassandra"
 
#include <freeradius-devel/server/base.h>
#include <freeradius-devel/util/debug.h>
 
#ifdef HAVE_WDOCUMENTATION
DIAG_OFF(documentation)
#endif
DIAG_OFF(strict-prototypes)  /* Seen with homebrew cassandra-cpp-driver 2.15.3 */
#include <cassandra.h>
DIAG_ON(strict-prototypes)
#ifdef HAVE_WDOCUMENTATION
DIAG_ON(documentation)
#endif
 
#include "rlm_sql.h"
#include "rlm_sql_trunk.h"
 
typedef struct {
        bool                    done_connect_keyspace;          //!< Whether we've connected to a keyspace.
        pthread_mutex_t         connect_mutex;                  //!< Mutex to prevent multiple connections attempting
                                                                ///< to connect to a keyspace concurrently.
} rlm_sql_cassandra_mutable_t;
 
/** Cassandra driver instance
 *
 */
typedef struct {
        CassCluster             *cluster;                       //!< Configuration of the cassandra cluster connection.
        CassSession             *session;                       //!< Cluster's connection pool.
        CassSsl                 *ssl;                           //!< Connection's SSL context.
        rlm_sql_cassandra_mutable_t     *mutable;               //!< Instance data which needs to change post instantiation.
 
        /*
         *      Configuration options
         */
        char const              *consistency_str;               //!< Level of consistency required.
        CassConsistency         consistency;                    //!< Level of consistency converted to a constant.
 
        uint32_t                protocol_version;               //!< The protocol version.
 
        uint32_t                connections_per_host;           //!< Number of connections to each server in each
                                                                //!< IO thread.
        uint32_t                io_threads;                     //!< Number of IO threads.
 
        uint32_t                io_queue_size;                  //!< Size of the the fixed size queue that stores
                                                                //!< pending requests.
 
        uint32_t                event_queue_size;               //!< Sets the size of the the fixed size queue
                                                                //!< that stores events.
 
        bool                    load_balance_round_robin;       //!< Enable round robin load balancing.
 
        bool                    token_aware_routing;            //!< Whether to use token aware routing.
 
        char const              *lbdc_local_dc;                 //!< The primary data center to try first.
        uint32_t                lbdc_hosts_per_remote_dc;       //!< The number of host used in each remote DC if
                                                                //!< no hosts are available in the local dc
 
        bool                    lbdc_allow_remote_dcs_for_local_cl;     //!< Allows remote hosts to be used if no local
                                                                //!< dc hosts are available and the consistency level
                                                                //!< is LOCAL_ONE or LOCAL_QUORUM.
 
        double                  lar_exclusion_threshold;        //!< How much worse the latency me be, compared to
                                                                //!< the average latency of the best performing node
                                                                //!< before it's penalized.
                                                                //!< This gets mangled to a double.
 
        fr_time_delta_t         lar_scale;                      //!< Weight given to older latencies when calculating
                                                                //!< the average latency of a node. A bigger scale will
                                                                //!< give more weight to older latency measurements.
 
        fr_time_delta_t         lar_retry_period;               //!< The amount of time a node is penalized by the
                                                                //!< policy before being given a second chance when
                                                                //!< the current average latency exceeds the calculated
                                                                //!< threshold
                                                                //!< (exclusion_threshold * best_average_latency).
 
        fr_time_delta_t         lar_update_rate;                //!< The rate at which the best average latency is
                                                                //!< recomputed.
        uint64_t                lar_min_measured;               //!< The minimum number of measurements per-host
                                                                //!< required to be considered by the policy.
 
        uint32_t                tcp_keepalive;                  //!< How often to send TCP keepalives.
        bool                    tcp_nodelay;                    //!< Disable TCP naggle algorithm.
 
        char const              *tls_ca_file;                   //!< Path to the CA used to validate the server's
                                                                //!< certificate.
        char const              *tls_certificate_file;          //!< Public certificate we present to the server.
        char const              *tls_private_key_file;          //!< Private key for the certificate we present to the
                                                                //!< server.
        char const              *tls_private_key_password;      //!< String to decrypt private key.
        char const              *tls_verify_cert_str;           //!< Whether we validate the cert provided by the
                                                                //!< server.
} rlm_sql_cassandra_t;
 
/** Cassandra cluster connection
 *
 */
typedef struct {
        connection_t            *conn;                          //!< Generic connection structure for managing this handle.
        rlm_sql_cassandra_t const       *inst;                  //!< Module instance for this connection.
        rlm_sql_config_t const  *config;                        //!< SQL instance config
        CassIterator            *iterator;                      //!< Row set iterator.
 
        TALLOC_CTX              *log_ctx;                       //!< Prevent unneeded memory allocation by keeping a
                                                                //!< permanent pool, to store log entries.
        fr_dlist_head_t         queries;                        //!< Outstanding queries on this connection.
        fr_event_timer_t const  *read_ev;                       //!< Polling event for reading query results.
        fr_event_timer_t const  *write_ev;                      //!< Polling event for sending queries.
        uint                    poll_interval;                  //!< Interval between read polling.
        uint                    poll_count;                     //!< How many consecutive polls had no available results.
} rlm_sql_cassandra_conn_t;
 
/** Structure for tracking outstanding queries
 *
 */
typedef struct {
        fr_dlist_t              entry;                          //!< Entry in list of outstanding queries.
        fr_sql_query_t          *query_ctx;                     //!< SQL query ctx.
        CassFuture              *future;                        //!< Future produced when submitting query.
} cassandra_query_t;
 
/** Driver specific data to attach to the query ctx
 *
 */
typedef struct {
        CassResult const        *result;                        //!< Cassandra result handle
        sql_log_entry_t         error;                          //!< Most recent Cassandra error message for this query.
} cassandra_query_ctx_t;
 
static fr_table_num_sorted_t const consistency_levels[] = {
        { L("all"),             CASS_CONSISTENCY_ALL            },
        { L("any"),             CASS_CONSISTENCY_ANY            },
        { L("each_quorum"),     CASS_CONSISTENCY_EACH_QUORUM    },
        { L("local_one"),       CASS_CONSISTENCY_LOCAL_ONE      },
        { L("local_quorum"),    CASS_CONSISTENCY_LOCAL_QUORUM   },
        { L("one"),             CASS_CONSISTENCY_ONE            },
        { L("quorum"),          CASS_CONSISTENCY_QUORUM         },
        { L("three"),           CASS_CONSISTENCY_THREE          },
        { L("two"),             CASS_CONSISTENCY_TWO            }
};
static size_t consistency_levels_len = NUM_ELEMENTS(consistency_levels);
 
static fr_table_num_sorted_t const verify_cert_table[] = {
        { L("identity"),                CASS_SSL_VERIFY_PEER_IDENTITY   },
        { L("no"),                      CASS_SSL_VERIFY_NONE            },
        { L("yes"),             CASS_SSL_VERIFY_PEER_CERT       }
};
static size_t verify_cert_table_len = NUM_ELEMENTS(verify_cert_table);
 
static conf_parser_t load_balance_dc_aware_config[] = {
        { FR_CONF_OFFSET("local_dc", rlm_sql_cassandra_t, lbdc_local_dc) },
        { FR_CONF_OFFSET("hosts_per_remote_dc", rlm_sql_cassandra_t, lbdc_hosts_per_remote_dc), .dflt = "0" },
        { FR_CONF_OFFSET("allow_remote_dcs_for_local_cl", rlm_sql_cassandra_t, lbdc_allow_remote_dcs_for_local_cl), .dflt = "no" },
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t latency_aware_routing_config[] = {
        { FR_CONF_OFFSET("exclusion_threshold", rlm_sql_cassandra_t, lar_exclusion_threshold), .dflt = "2.0" },
        { FR_CONF_OFFSET("scale", rlm_sql_cassandra_t, lar_scale), .dflt = "0.1" },
        { FR_CONF_OFFSET("retry_period", rlm_sql_cassandra_t, lar_retry_period), .dflt = "10" },
        { FR_CONF_OFFSET("update_rate", rlm_sql_cassandra_t, lar_update_rate), .dflt = "0.1" },
        { FR_CONF_OFFSET("min_measured", rlm_sql_cassandra_t, lar_min_measured), .dflt = "50" },
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t tls_config[] = {
        { FR_CONF_OFFSET_FLAGS("ca_file", CONF_FLAG_FILE_INPUT, rlm_sql_cassandra_t, tls_ca_file) },
        { FR_CONF_OFFSET_FLAGS("certificate_file", CONF_FLAG_FILE_INPUT, rlm_sql_cassandra_t, tls_certificate_file) },
        { FR_CONF_OFFSET_FLAGS("private_key_file", CONF_FLAG_FILE_INPUT, rlm_sql_cassandra_t, tls_private_key_file) },
        { FR_CONF_OFFSET_FLAGS("private_key_password", CONF_FLAG_SECRET, rlm_sql_cassandra_t, tls_private_key_password) },
 
        { FR_CONF_OFFSET("verify_cert", rlm_sql_cassandra_t, tls_verify_cert_str) },
        CONF_PARSER_TERMINATOR
};
 
static const conf_parser_t driver_config[] = {
        { FR_CONF_OFFSET("consistency", rlm_sql_cassandra_t, consistency_str), .dflt = "quorum" },
 
        { FR_CONF_OFFSET("protocol_version", rlm_sql_cassandra_t, protocol_version) },
 
        { FR_CONF_OFFSET("connections_per_host", rlm_sql_cassandra_t, connections_per_host) },
 
        { FR_CONF_OFFSET("io_threads", rlm_sql_cassandra_t, io_threads) },
        { FR_CONF_OFFSET("io_queue_size", rlm_sql_cassandra_t, io_queue_size) },
 
        { FR_CONF_OFFSET("event_queue_size", rlm_sql_cassandra_t, event_queue_size) },
 
        { FR_CONF_POINTER("load_balance_dc_aware", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) load_balance_dc_aware_config },
        { FR_CONF_OFFSET("load_balance_round_robin", rlm_sql_cassandra_t, load_balance_round_robin), .dflt = "no" },
 
        { FR_CONF_OFFSET("token_aware_routing", rlm_sql_cassandra_t, token_aware_routing), .dflt = "yes" },
        { FR_CONF_POINTER("latency_aware_routing", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) latency_aware_routing_config },
 
        { FR_CONF_OFFSET("tcp_keepalive", rlm_sql_cassandra_t, tcp_keepalive) },
        { FR_CONF_OFFSET("tcp_nodelay", rlm_sql_cassandra_t, tcp_nodelay), .dflt = "no" },
 
        { FR_CONF_POINTER("tls", 0, CONF_FLAG_SUBSECTION | CONF_FLAG_OK_MISSING, NULL), .subcs = (void const *) tls_config },
        CONF_PARSER_TERMINATOR
};
 
/** Log callback for libcassandra
 *
 * libcassandra seems to use this to log global events in the library, other messages
 * like query errors are not logged here, and should be retrieved with functions like
 * cass_future_error_message();
 *
 * Messages here do not need to be made available via sql_error.
 *
 * @param message Contains the log message and information about its source.
 * @param data user data (not used).
 */
static void _rlm_sql_cassandra_log(CassLogMessage const *message, UNUSED void *data)
{
        switch (message->severity) {
        case CASS_LOG_CRITICAL:
        case CASS_LOG_ERROR:
                if (DEBUG_ENABLED3) {
                        ERROR("%s[%d] %s: %s",
                               message->file, message->line, message->function, message->message);
                } else {
                        ERROR("%s", message->message);
                }
                return;
 
        case CASS_LOG_WARN:
                if (DEBUG_ENABLED3) {
                        WARN("%s[%d] %s: %s",
                             message->file, message->line, message->function, message->message);
                } else {
                        WARN("%s", message->message);
                }
                return;
 
        case CASS_LOG_INFO:
        case CASS_LOG_DISABLED:
        case CASS_LOG_LAST_ENTRY:
                if (DEBUG_ENABLED3) {
                        INFO("%s[%d] %s: %s",
                             message->file, message->line, message->function, message->message);
                } else {
                        INFO("%s", message->message);
                }
                return;
 
        case CASS_LOG_DEBUG:
        case CASS_LOG_TRACE:
        default:
                if (DEBUG_ENABLED3) {
                        DEBUG3("%s[%d] %s: %s",
                               message->file, message->line, message->function, message->message);
                } else {
                        DEBUG2("%s", message->message);
                }
                return;
        }
}
 
/** Store the last error associated with a query
 *
 * @param ctx to allocate message in
 * @param cass_query_ctx cassandra query context to write error message into.
 * @param message from libcassandra.
 * @param len of message.
 */
static void sql_set_query_error(TALLOC_CTX *ctx, cassandra_query_ctx_t *cass_query_ctx, char const *message, size_t len)
{
        talloc_const_free(cass_query_ctx->error.msg);
        cass_query_ctx->error.msg = fr_asprint(ctx, message, len, '\0');
        cass_query_ctx->error.type = L_ERR;
}
 
 
/** Store the last error associated with a query, using a format string
 *
 * @param ctx to allocate messate in.
 * @param cass_query_ctx to replace log message in.
 * @param fmt of message.
 * @param ... args.
 */
static void sql_set_query_error_printf(TALLOC_CTX *ctx, cassandra_query_ctx_t *cass_query_ctx, char const *fmt, ...)
        CC_HINT(format (printf, 3, 4));
static void sql_set_query_error_printf(TALLOC_CTX *ctx, cassandra_query_ctx_t *cass_query_ctx, char const *fmt, ...)
{
        va_list ap;
 
        talloc_const_free(cass_query_ctx->error.msg);
        va_start(ap, fmt);
        cass_query_ctx->error.msg = talloc_vasprintf(ctx, fmt, ap);
        va_end(ap);
        cass_query_ctx->error.type = L_ERR;
}
 
static void _sql_connection_close(UNUSED fr_event_list_t *el, void *h, UNUSED void *uctx)
{
        rlm_sql_cassandra_conn_t *conn = talloc_get_type_abort(h, rlm_sql_cassandra_conn_t);
 
        DEBUG2("Socket destructor called, closing socket");
 
        if (conn->iterator) cass_iterator_free(conn->iterator);
        talloc_free(h);
}
 
CC_NO_UBSAN(function) /* UBSAN: false positive - public vs private connection_t trips --fsanitize=function */
static connection_state_t _sql_connection_init(void **h, connection_t *conn, void *uctx)
{
        rlm_sql_t const                 *sql = talloc_get_type_abort_const(uctx, rlm_sql_t);
        rlm_sql_config_t const          *config = &sql->config;
        rlm_sql_cassandra_t             *inst = talloc_get_type_abort(sql->driver_submodule->data, rlm_sql_cassandra_t);
        rlm_sql_cassandra_conn_t        *c;
 
        MEM(c = talloc_zero(conn, rlm_sql_cassandra_conn_t));
        *c = (rlm_sql_cassandra_conn_t) {
                .conn = conn,
                .inst = inst,
                .config = config,
                .log_ctx = talloc_pool(c, 2048),                /* Pre-allocate some memory for log messages */
                .poll_interval = 1000
        };
 
        *h = c;
 
        /*
         *      We do this one inside sql_socket_init, to allow pool.start = 0 to
         *      work as expected (allow the server to start if Cassandra is
         *      unavailable).
         */
        if (!inst->mutable->done_connect_keyspace) {
                CassFuture      *future;
                CassError       ret;
 
                pthread_mutex_lock(&inst->mutable->connect_mutex);
                if (!inst->mutable->done_connect_keyspace) {
                        /*
                         *      Easier to do this here instead of mod_instantiate
                         *      as we don't have a pointer to the pool.
                         */
                        cass_cluster_set_connect_timeout(inst->cluster, fr_time_delta_to_msec(config->trunk_conf.conn_conf->connection_timeout));
 
                        DEBUG2("Connecting to Cassandra cluster");
                        future = cass_session_connect_keyspace(inst->session, inst->cluster, config->sql_db);
                        ret = cass_future_error_code(future);
                        if (ret != CASS_OK) {
                                const char      *msg;
                                size_t          msg_len;
 
                                cass_future_error_message(future, &msg, &msg_len);
                                ERROR("Unable to connect: [%x] %s", (int)ret, msg);
                                cass_future_free(future);
                                pthread_mutex_unlock(&inst->mutable->connect_mutex);
 
                                return CONNECTION_STATE_FAILED;
                        }
                        cass_future_free(future);
                        inst->mutable->done_connect_keyspace = true;
                }
                pthread_mutex_unlock(&inst->mutable->connect_mutex);
        }
 
        fr_dlist_init(&c->queries, cassandra_query_t, entry);
 
        return CONNECTION_STATE_CONNECTED;
}
 
SQL_TRUNK_CONNECTION_ALLOC
 
CC_NO_UBSAN(function) /* UBSAN: false positive - public vs private connection_t trips --fsanitize=function */
static void sql_trunk_request_mux(UNUSED fr_event_list_t *el, trunk_connection_t *tconn,
                                  connection_t *conn, UNUSED void *uctx)
{
        rlm_sql_cassandra_conn_t        *sql_conn = talloc_get_type_abort(conn->h, rlm_sql_cassandra_conn_t);
        rlm_sql_cassandra_t const       *inst = sql_conn->inst;
        request_t                       *request;
        trunk_request_t                 *treq;
        fr_sql_query_t                  *query_ctx;
        CassStatement                   *statement;
        cassandra_query_t               *cass_query;
        cassandra_query_ctx_t           *cass_query_ctx;
 
        while (trunk_connection_pop_request(&treq, tconn) == 0) {
                if (!treq) return;
 
                query_ctx = talloc_get_type_abort(treq->preq, fr_sql_query_t);
                request = query_ctx->request;
 
                switch (query_ctx->status) {
                case SQL_QUERY_PREPARED:
                        ROPTIONAL(RDEBUG2, DEBUG2, "Executing query: %s", query_ctx->query_str);
                        statement = cass_statement_new_n(query_ctx->query_str, talloc_array_length(query_ctx->query_str) - 1, 0);
                        if (inst->consistency_str) cass_statement_set_consistency(statement, inst->consistency);
 
                        /*
                         *      Allocate tracking and driver specific structures.
                         */
                        MEM(cass_query = talloc_zero(conn, cassandra_query_t));
                        MEM(cass_query_ctx = talloc_zero(query_ctx, cassandra_query_ctx_t));
                        query_ctx->uctx = cass_query_ctx;
 
                        /*
                         *      Executing the query returns a future which will later be polled for its result.
                         *      Failures are not visible at this point.
                         */
                        cass_query->future = cass_session_execute(inst->session, statement);
                        cass_query->query_ctx = query_ctx;
 
                        /*
                         *      Insert the tracking structure into the list of outstanding queries.
                         */
                        fr_dlist_insert_tail(&sql_conn->queries, cass_query);
                        query_ctx->status = SQL_QUERY_SUBMITTED;
                        query_ctx->tconn = tconn;
                        trunk_request_signal_sent(treq);
                        return;
 
                default:
                        return;
                }
        }
}
 
static void sql_trunk_connection_read_poll(UNUSED fr_event_list_t *el, UNUSED fr_time_t now, void *uctx)
{
        rlm_sql_cassandra_conn_t        *c = talloc_get_type_abort(uctx, rlm_sql_cassandra_conn_t);
        cassandra_query_t               *cass_query, *next_query = NULL;
        fr_sql_query_t                  *query_ctx;
        cassandra_query_ctx_t           *cass_query_ctx;
        CassError                       ret;
        request_t                       *request;
        bool                            handled = false;
 
        next_query = fr_dlist_head(&c->queries);
        while (next_query) {
                /*
                 *      If the future is not ready, move to the next.
                 */
                if (!cass_future_ready(next_query->future)) goto next;
 
                cass_query = next_query;
                next_query = fr_dlist_remove(&c->queries, cass_query);
 
                query_ctx = cass_query->query_ctx;
                request = query_ctx->request;
                handled = true;
                cass_query_ctx = talloc_get_type_abort(query_ctx->uctx, cassandra_query_ctx_t);
 
                ret = cass_future_error_code(cass_query->future);
                if (ret != CASS_OK) {
                        char const      *error;
                        size_t          len;
 
                        cass_future_error_message(cass_query->future, &error, &len);
                        sql_set_query_error(c->log_ctx, cass_query_ctx, error, len);
 
                        switch (ret) {
                        case CASS_ERROR_SERVER_SYNTAX_ERROR:
                        case CASS_ERROR_SERVER_INVALID_QUERY:
                                query_ctx->rcode = RLM_SQL_QUERY_INVALID;
                                break;
 
                        default:
                                query_ctx->rcode = RLM_SQL_ERROR;
                        }
                        trunk_request_signal_fail(query_ctx->treq);
                        cass_future_free(cass_query->future);
                        talloc_free(cass_query);
                        goto next;
                }
 
                query_ctx->rcode = RLM_SQL_OK;
                cass_query_ctx->result = cass_future_get_result(cass_query->future);
                cass_future_free(cass_query->future);
                if (request) unlang_interpret_mark_runnable(request);
                talloc_free(cass_query);
        next:
                next_query = fr_dlist_next(&c->queries, next_query);
        }
 
        /*
         *      Adjust poll interval.  The aim is to return results as fast as
         *      possible, but without over polling.
         */
        if (!handled) {
                /*
                 *      Nothing was ready - increase the interval
                 */
                if (c->poll_interval < fr_time_delta_to_usec(c->config->query_timeout)/2) c->poll_interval += 100;
                c->poll_count ++;
        } else {
                /*
                 *      Results were immediately available - decrease the interval
                 */
                if (c->poll_count == 0) {
                        c->poll_interval /= 2;
                }
                c->poll_count = 0;
        }
 
        /*
         *      There are still outstanding queries, add another polling event
         */
        if (fr_dlist_num_elements(&c->queries)) {
                if (fr_event_timer_in(c, el, &c->read_ev, fr_time_delta_from_usec(c->poll_interval),
                                      sql_trunk_connection_read_poll, c) < 0) {
                        ERROR("Unable to insert polling event");
                }
        }
}
 
static void sql_trunk_connection_write_poll(UNUSED fr_event_list_t *el, UNUSED fr_time_t now, void *uctx)
{
        trunk_connection_t      *tconn = talloc_get_type_abort(uctx, trunk_connection_t);
 
        trunk_connection_signal_writable(tconn);
}
 
/*
 *      While libcassandra support installing callbacks to handle futures being set,
 *      in testing, in the callback attempting to retrieve the error status of the
 *      future locked up.  So we have to resort to polling.
 *
 *      This "notify" callback sets up the appropriate polling events.
 */
CC_NO_UBSAN(function) /* UBSAN: false positive - public vs private connection_t trips --fsanitize=function */
static void sql_trunk_connection_notify(UNUSED trunk_connection_t *tconn, connection_t *conn, UNUSED fr_event_list_t *el,
                                        trunk_connection_event_t notify_on, UNUSED void *uctx)
{
        rlm_sql_cassandra_conn_t        *c = talloc_get_type_abort(conn->h, rlm_sql_cassandra_conn_t);
 
        switch (notify_on) {
        case TRUNK_CONN_EVENT_NONE:
                if (c->read_ev) fr_event_timer_delete(&c->read_ev);
                if (c->write_ev) fr_event_timer_delete(&c->write_ev);
                return;
 
        case TRUNK_CONN_EVENT_BOTH:
        case TRUNK_CONN_EVENT_READ:
                if (fr_dlist_num_elements(&c->queries)) {
                        if (fr_event_timer_in(c, el, &c->read_ev, fr_time_delta_from_usec(c->poll_interval),
                                              sql_trunk_connection_read_poll, c) < 0) {
                                ERROR("Unable to insert polling event");
                        }
                }
                if (notify_on == TRUNK_CONN_EVENT_READ) return;
 
                FALL_THROUGH;
 
        case TRUNK_CONN_EVENT_WRITE:
                if (fr_event_timer_in(c, el, &c->write_ev, fr_time_delta_from_usec(0),
                                      sql_trunk_connection_write_poll, tconn) < 0) {
                        ERROR("Unable to insert polling event");
                }
                return;
        }
}
 
SQL_QUERY_RESUME
SQL_QUERY_FAIL
 
CC_NO_UBSAN(function) /* UBSAN: false positive - public vs private connection_t trips --fsanitize=function */
static void sql_request_cancel(connection_t *conn, void *preq, trunk_cancel_reason_t reason,
                               UNUSED void *uctx)
{
        fr_sql_query_t                  *query_ctx = talloc_get_type_abort(preq, fr_sql_query_t);
        rlm_sql_cassandra_conn_t        *sql_conn = talloc_get_type_abort(conn->h, rlm_sql_cassandra_conn_t);
        cassandra_query_t               *cass_query = NULL;
 
        if (!query_ctx->treq) return;
        if (reason != TRUNK_CANCEL_REASON_SIGNAL) return;
 
        /*
         *      There is no query cancellation for Cassandra.
         *      So, remove the query from the list of outstanding queries so
         *      if it does return, we don't do anything.
         */
        while ((cass_query = fr_dlist_next(&sql_conn->queries, cass_query))) {
                if (cass_query->query_ctx == query_ctx) {
                        fr_dlist_remove(&sql_conn->queries, cass_query);
                        cass_future_free(cass_query->future);
                        return;
                }
        }
}
 
static int sql_num_rows(fr_sql_query_t *query_ctx, UNUSED rlm_sql_config_t const *config)
{
        cassandra_query_ctx_t   *cass_query_ctx = query_ctx->uctx;
 
        return cass_query_ctx->result ? cass_result_row_count(cass_query_ctx->result) : 0;
}
 
static sql_rcode_t sql_fields(char const **out[], fr_sql_query_t *query_ctx, UNUSED rlm_sql_config_t const *config)
{
        cassandra_query_ctx_t   *cass_query_ctx = query_ctx->uctx;
        CassResult const        *result = cass_query_ctx->result;
 
        unsigned int    fields, i;
        char const      **names;
 
        fields = result ? cass_result_column_count(result) : 0;
        if (fields == 0) return RLM_SQL_ERROR;
 
        MEM(names = talloc_array(query_ctx, char const *, fields));
 
        for (i = 0; i < fields; i++) {
                const char *col_name;
                size_t     col_name_len;
 
                /* Writes out a pointer to a buffer in the result */
                if (cass_result_column_name(result, i, &col_name, &col_name_len) != CASS_OK) {
                        col_name = "<INVALID>";
                }
                names[i] = col_name;
        }
 
        *out = names;
 
        return RLM_SQL_OK;
}
 
static unlang_action_t sql_fetch_row(rlm_rcode_t *p_result, UNUSED int *priority, UNUSED request_t *request, void *uctx)
{
        fr_sql_query_t                  *query_ctx = talloc_get_type_abort(uctx, fr_sql_query_t);
        rlm_sql_cassandra_conn_t        *conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_cassandra_conn_t);
        CassRow const                   *cass_row;
        cassandra_query_ctx_t           *cass_query_ctx = query_ctx->uctx;
        CassResult const                *result = cass_query_ctx->result;
        int                             fields, i;
        char                            **row;
 
#define RLM_CASS_ERR_DATA_RETRIVE(_t) \
do {\
        char const *_col_name;\
        size_t _col_name_len;\
        CassError _ret;\
        if ((_ret = cass_result_column_name(result, i, &_col_name, &_col_name_len)) != CASS_OK) {\
                _col_name = "<INVALID>";\
        }\
        sql_set_query_error_printf(conn->log_ctx, cass_query_ctx, "Failed to retrieve " _t " data at column %s (%d): %s", \
                                  _col_name, i, cass_error_desc(_ret));\
        TALLOC_FREE(query_ctx->row);\
        query_ctx->rcode = RLM_SQL_ERROR;\
        RETURN_MODULE_FAIL;\
} while(0)
 
        query_ctx->rcode = RLM_SQL_OK;
        if (!result) RETURN_MODULE_OK;                                  /* no result */
 
        /*
         *      Start of the result set, initialise the iterator.
         */
        if (!conn->iterator) conn->iterator = cass_iterator_from_result(result);
        if (!conn->iterator) RETURN_MODULE_OK;                          /* no result */
 
        /*
         *      Free the previous result (also gets called on finish_query)
         */
        TALLOC_FREE(query_ctx->row);
 
        if (!cass_iterator_next(conn->iterator)) {
                query_ctx->rcode = RLM_SQL_NO_MORE_ROWS;                /* no more rows */
                RETURN_MODULE_OK;
        }
 
        cass_row = cass_iterator_get_row(conn->iterator);               /* this shouldn't fail ? */
        fields = cass_result_column_count(result);                      /* get the number of fields... */
 
        MEM(row = query_ctx->row = talloc_zero_array(query_ctx, char *, fields + 1));
 
        for (i = 0; i < fields; i++) {
                CassValue const *value;
                CassValueType   type;
 
                value = cass_row_get_column(cass_row, i);
 
                if (cass_value_is_null(value) == cass_true) continue;
 
                type = cass_value_type(value);
                switch (type) {
                case CASS_VALUE_TYPE_ASCII:
                case CASS_VALUE_TYPE_TEXT:
                case CASS_VALUE_TYPE_VARCHAR:
                {
                        const char      *str;
                        size_t          len;
 
                        if (cass_value_get_string(value, &str, &len) != CASS_OK) RLM_CASS_ERR_DATA_RETRIVE("string");
 
                        MEM(row[i] = talloc_array(row, char, len + 1));
                        memcpy(row[i], str, len);
                        row[i][len] = '\0';
                }
                        break;
 
                case CASS_VALUE_TYPE_BOOLEAN:
                {
                        cass_bool_t bv;
 
                        if (cass_value_get_bool(value, &bv) != CASS_OK) RLM_CASS_ERR_DATA_RETRIVE("bool");
 
                        MEM(row[i] = talloc_zero_array(row, char, 2));
                        row[i][0] = (bv == cass_false) ? '0' : '1';
                }
                        break;
 
                case CASS_VALUE_TYPE_INT:
                {
                        cass_int32_t i32v;
 
                        if (cass_value_get_int32(value, &i32v) != CASS_OK) RLM_CASS_ERR_DATA_RETRIVE("int32");
 
                        MEM(row[i] = talloc_typed_asprintf(row, "%"PRId32, (int32_t)i32v));
                }
                        break;
 
                case CASS_VALUE_TYPE_TIMESTAMP:
                case CASS_VALUE_TYPE_BIGINT:
                {
                        cass_int64_t i64v;
 
                        if (cass_value_get_int64(value, &i64v) != CASS_OK) RLM_CASS_ERR_DATA_RETRIVE("int64");
 
                        MEM(row[i] = talloc_typed_asprintf(row, "%"PRId64, (int64_t)i64v));
                }
                        break;
 
                case CASS_VALUE_TYPE_UUID:
                case CASS_VALUE_TYPE_TIMEUUID:
                {
                        CassUuid uuid;
 
                        if (cass_value_get_uuid(value, &uuid) != CASS_OK) RLM_CASS_ERR_DATA_RETRIVE("UUID");
                        MEM(row[i] = talloc_array(row, char, CASS_UUID_STRING_LENGTH));
                        cass_uuid_string(uuid, row[i]);
                }
                        break;
 
                default:
                {
                        const char *col_name;
                        size_t     col_name_len;
 
                        if (cass_result_column_name(result, i, &col_name,
                                                    &col_name_len) != CASS_OK) col_name = "<INVALID>";
 
                        sql_set_query_error_printf(conn->log_ctx, cass_query_ctx,
                                                  "Failed to retrieve data at column %s (%d): Unsupported data type",
                                                  col_name, i);
                        talloc_free(query_ctx->row);
                        query_ctx->rcode = RLM_SQL_ERROR;
                        RETURN_MODULE_FAIL;
                }
                }
        }
 
        RETURN_MODULE_OK;
}
 
static sql_rcode_t sql_free_result(fr_sql_query_t *query_ctx, UNUSED rlm_sql_config_t const *config)
{
        rlm_sql_cassandra_conn_t        *conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_cassandra_conn_t);
 
        if (query_ctx->row) TALLOC_FREE(query_ctx->row);
 
        if (conn->iterator) {
                cass_iterator_free(conn->iterator);
                conn->iterator = NULL;
        }
 
        if (query_ctx->uctx) {
                CassResult const *result = query_ctx->uctx;
                cass_result_free(result);
                query_ctx->uctx = NULL;
        }
 
        return RLM_SQL_OK;
}
 
static size_t sql_error(UNUSED TALLOC_CTX *ctx, sql_log_entry_t out[], size_t outlen,
                        fr_sql_query_t *query_ctx)
{
        cassandra_query_ctx_t   *cass_query_ctx = talloc_get_type_abort(query_ctx->uctx, cassandra_query_ctx_t);
 
        if (cass_query_ctx->error.msg && (outlen >= 1)) {
                out[0].msg = cass_query_ctx->error.msg;
                out[0].type = cass_query_ctx->error.type;
 
                return 1;
        }
 
        return 0;
}
 
static sql_rcode_t sql_finish_query(fr_sql_query_t *query_ctx, rlm_sql_config_t const *config)
{
        cassandra_query_ctx_t   *cass_query_ctx = talloc_get_type_abort(query_ctx->uctx, cassandra_query_ctx_t);
 
        talloc_const_free(cass_query_ctx->error.msg);
 
        return sql_free_result(query_ctx, config);
}
 
/*
 *      The cassandra model is different, as it's distributed, and does
 *      upserts instead of inserts...
 *
 *      There's a good article on it here:
 *              http://planetcassandra.org/blog/how-to-do-an-upsert-in-cassandra/
 */
static int sql_affected_rows(UNUSED fr_sql_query_t *query_ctx, UNUSED rlm_sql_config_t const *config)
{
        return 1;
}
 
static int mod_detach(module_detach_ctx_t const *mctx)
{
        rlm_sql_cassandra_t *inst = talloc_get_type_abort(mctx->mi->data, rlm_sql_cassandra_t);
 
        if (inst->ssl) cass_ssl_free(inst->ssl);
        if (inst->session) cass_session_free(inst->session);    /* also synchronously closes the session */
        if (inst->cluster) cass_cluster_free(inst->cluster);
 
        pthread_mutex_destroy(&inst->mutable->connect_mutex);
        talloc_free(inst->mutable);
 
        return 0;
}
 
static int mod_instantiate(module_inst_ctx_t const *mctx)
{
        rlm_sql_t const         *parent = talloc_get_type_abort(mctx->mi->parent->data, rlm_sql_t);
        rlm_sql_config_t const  *config = &parent->config;
        rlm_sql_cassandra_t     *inst = talloc_get_type_abort(mctx->mi->data, rlm_sql_cassandra_t);
        bool                    do_tls = false;
        bool                    do_latency_aware_routing = false;
        CassCluster             *cluster;
        int                     ret;
 
#define DO_CASS_OPTION(_opt, _x) \
do {\
        CassError _ret;\
        if ((_ret = (_x)) != CASS_OK) {\
                ERROR("Error setting " _opt ": %s", cass_error_desc(_ret));\
                return -1;\
        }\
} while (0)
 
        MEM(inst->mutable = talloc_zero(NULL, rlm_sql_cassandra_mutable_t));
        if ((ret = pthread_mutex_init(&inst->mutable->connect_mutex, NULL)) < 0) {
                ERROR("Failed initializing mutex: %s", fr_syserror(ret));
                TALLOC_FREE(inst);
                return -1;
        }
 
        /*
         *      This has to be done before we call cf_section_parse
         *      as it sets default values, and creates the section.
         */
        if (cf_section_find(mctx->mi->conf, "tls", NULL)) do_tls = true;
        if (cf_section_find(mctx->mi->conf, "latency_aware_routing", NULL)) do_latency_aware_routing = true;
 
        DEBUG4("Configuring CassCluster structure");
        cluster = inst->cluster = cass_cluster_new();
        if (!cluster) return -1;
 
        /*
         *      Parameters inherited from the top level SQL module config
         */
        DO_CASS_OPTION("sql_server", cass_cluster_set_contact_points(cluster, config->sql_server));
        if (config->sql_port) DO_CASS_OPTION("sql_port", cass_cluster_set_port(cluster, config->sql_port));
        /* Can't fail */
        if (fr_time_delta_ispos(config->query_timeout)) {
                cass_cluster_set_request_timeout(cluster, fr_time_delta_to_msec(config->query_timeout));
        }
 
        /* Can't fail */
        if (config->sql_login && config->sql_password) cass_cluster_set_credentials(cluster, config->sql_login,
                                                                                    config->sql_password);
 
        /*
         *      inst specific parameters
         */
        if (inst->consistency_str) {
                int consistency;
 
                consistency = fr_table_value_by_str(consistency_levels, inst->consistency_str, -1);
                if (consistency < 0) {
                        ERROR("Invalid consistency level \"%s\"", inst->consistency_str);
                        return -1;
                }
                inst->consistency = (CassConsistency)consistency;
        }
 
        if (inst->protocol_version) {
                DO_CASS_OPTION("protocol_version",
                               cass_cluster_set_protocol_version(inst->cluster, inst->protocol_version));
        }
 
        if (inst->connections_per_host) {
                DO_CASS_OPTION("connections_per_host",
                               cass_cluster_set_core_connections_per_host(inst->cluster,
                                                                          inst->connections_per_host));
        }
 
        if (inst->event_queue_size) {
                DO_CASS_OPTION("event_queue_size",
                               cass_cluster_set_num_threads_io(inst->cluster, inst->event_queue_size));
        }
 
        if (inst->io_queue_size) {
                DO_CASS_OPTION("io_queue_size",
                               cass_cluster_set_num_threads_io(inst->cluster, inst->io_queue_size));
        }
 
        if (inst->io_threads) {
                DO_CASS_OPTION("io_threads", cass_cluster_set_num_threads_io(inst->cluster, inst->io_threads));
        }
 
        if (inst->load_balance_round_robin) cass_cluster_set_load_balance_round_robin(inst->cluster);
 
        cass_cluster_set_token_aware_routing(inst->cluster, inst->token_aware_routing);
 
        if (inst->lbdc_local_dc) {
                DO_CASS_OPTION("load_balance_dc_aware",
                               cass_cluster_set_load_balance_dc_aware(inst->cluster,
                                                                      inst->lbdc_local_dc,
                                                                      inst->lbdc_hosts_per_remote_dc,
                                                                      inst->lbdc_allow_remote_dcs_for_local_cl));
        }
 
        if (do_latency_aware_routing) {
                /* Can't fail */
                cass_cluster_set_latency_aware_routing(inst->cluster, true);
 
                /* Can't fail */
                cass_cluster_set_latency_aware_routing_settings(inst->cluster,
                                                                (cass_double_t)inst->lar_exclusion_threshold,
                                                                fr_time_delta_to_msec(inst->lar_scale),
                                                                fr_time_delta_to_msec(inst->lar_retry_period),
                                                                fr_time_delta_to_msec(inst->lar_update_rate),
                                                                inst->lar_min_measured);
        }
 
        if (inst->tcp_keepalive) cass_cluster_set_tcp_keepalive(inst->cluster, true, inst->tcp_keepalive);
        cass_cluster_set_tcp_nodelay(inst->cluster, inst->tcp_nodelay);
 
        if (do_tls) {
                CassSsl *ssl;
 
                ssl = inst->ssl = cass_ssl_new();
                if (!ssl) return -1;
 
                if (inst->tls_verify_cert_str) {
                        int     verify_cert;
 
                        verify_cert = fr_table_value_by_str(verify_cert_table, inst->tls_verify_cert_str, -1);
                        if (verify_cert < 0) {
                                ERROR("Invalid certificate validation type \"%s\", "
                                      "must be one of 'yes', 'no', 'identity'", inst->tls_verify_cert_str);
                                return -1;
                        }
                        cass_ssl_set_verify_flags(ssl, verify_cert);
                }
 
                DEBUG2("Enabling TLS");
 
                if (inst->tls_ca_file) {
                        DO_CASS_OPTION("ca_file", cass_ssl_add_trusted_cert(ssl, inst->tls_ca_file));
                }
 
                if (inst->tls_certificate_file) {
                        DO_CASS_OPTION("certificate_file", cass_ssl_set_cert(ssl, inst->tls_certificate_file));
                }
 
                if (inst->tls_private_key_file) {
                        DO_CASS_OPTION("private_key", cass_ssl_set_private_key(ssl, inst->tls_private_key_file,
                                                                               inst->tls_private_key_password));
                }
 
                cass_cluster_set_ssl(cluster, ssl);
        }
 
        inst->session = cass_session_new();
        if (!inst->session) return -1;
 
        return 0;
}
 
static int mod_load(void)
{
        INFO("Built against libcassandra version %d.%d.%d%s",
             CASS_VERSION_MAJOR, CASS_VERSION_MINOR, CASS_VERSION_PATCH, CASS_VERSION_SUFFIX);
 
        /*
         *      Setup logging callbacks (only needs to be done once)
         */
        cass_log_set_level(CASS_LOG_INFO);
        cass_log_set_callback(_rlm_sql_cassandra_log, NULL);
 
        return 0;
}
 
/* Exported to rlm_sql */
extern rlm_sql_driver_t rlm_sql_cassandra;
rlm_sql_driver_t rlm_sql_cassandra = {
        .common = {
                .name                           = "sql_cassandra",
                .magic                          = MODULE_MAGIC_INIT,
                .inst_size                      = sizeof(rlm_sql_cassandra_t),
                .onload                         = mod_load,
                .config                         = driver_config,
                .instantiate                    = mod_instantiate,
                .detach                         = mod_detach
        },
        .flags                          = RLM_SQL_MULTI_QUERY_CONN,
        .sql_query_resume               = sql_query_resume,
        .sql_select_query_resume        = sql_query_resume,
        .sql_num_rows                   = sql_num_rows,
        .sql_affected_rows              = sql_affected_rows,
        .sql_fields                     = sql_fields,
        .sql_fetch_row                  = sql_fetch_row,
        .sql_free_result                = sql_free_result,
        .sql_error                      = sql_error,
        .sql_finish_query               = sql_finish_query,
        .sql_finish_select_query        = sql_finish_query,
        .uses_trunks                    = true,
        .trunk_io_funcs = {
                .connection_alloc       = sql_trunk_connection_alloc,
                .connection_notify      = sql_trunk_connection_notify,
                .request_mux            = sql_trunk_request_mux,
                .request_cancel         = sql_request_cancel,
                .request_fail           = sql_request_fail
        }
};