rlm_sql_mysql.c

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/*
 *   This program 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: 4043b4070f030956dbd9e6236ae01db34b3d3ba2 $
 * @file rlm_sql_mysql.c
 * @brief MySQL driver.
 *
 * @copyright 2014-2015 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 * @copyright 2000-2007,2015 The FreeRADIUS server project
 * @copyright 2000 Mike Machado (mike@innercite.com)
 * @copyright 2000 Alan DeKok (aland@freeradius.org)
 */
RCSID("$Id: 4043b4070f030956dbd9e6236ae01db34b3d3ba2 $")
 
#define LOG_PREFIX "sql - mysql"
 
#include <freeradius-devel/server/base.h>
#include <freeradius-devel/util/debug.h>
 
#include <sys/stat.h>
 
#include "config.h"
 
#ifdef HAVE_MYSQL_MYSQL_H
#  include <mysql/errmsg.h>
DIAG_OFF(strict-prototypes)     /* Seen with homebrew mysql client 5.7.13 */
#  include <mysql/mysql.h>
DIAG_ON(strict-prototypes)
#  include <mysql/mysqld_error.h>
#elif defined(HAVE_MYSQL_H)
#  include <errmsg.h>
DIAG_OFF(strict-prototypes)     /* Seen with homebrew mysql client 5.7.13 */
#  include <mysql.h>
DIAG_ON(strict-prototypes)
#  include <mysqld_error.h>
#endif
 
#include "rlm_sql.h"
 
typedef enum {
        SERVER_WARNINGS_AUTO = 0,
        SERVER_WARNINGS_YES,
        SERVER_WARNINGS_NO
} rlm_sql_mysql_warnings;
 
static fr_table_num_sorted_t const server_warnings_table[] = {
        { L("auto"),    SERVER_WARNINGS_AUTO    },
        { L("no"),              SERVER_WARNINGS_NO      },
        { L("yes"),     SERVER_WARNINGS_YES     }
};
static size_t server_warnings_table_len = NUM_ELEMENTS(server_warnings_table);
 
typedef struct {
        MYSQL           db;                     //!< Structure representing connection details.
        MYSQL           *sock;                  //!< Connection details as returned by connection init functions.
        MYSQL_RES       *result;                //!< Result from most recent query.
        connection_t    *conn;                  //!< Generic connection structure for this connection.
        int             fd;                     //!< fd for this connection's I/O events.
        fr_sql_query_t  *query_ctx;             //!< Current query running on this connection.
        int             status;                 //!< returned by the most recent non-blocking function call.
} rlm_sql_mysql_conn_t;
 
typedef struct {
        char const      *tls_ca_file;           //!< Path to the CA used to validate the server's certificate.
        char const      *tls_ca_path;           //!< Directory containing CAs that may be used to validate the
                                                //!< servers 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_crl_file;          //!< Public certificate we present to the server.
        char const      *tls_crl_path;          //!< Private key for the certificate we present to the server.
 
        char const      *tls_cipher;            //!< Colon separated list of TLS ciphers for TLS <= 1.2.
 
        bool            tls_required;           //!< Require that the connection is encrypted.
        bool            tls_check_cert;         //!< Verify there's a trust relationship between the server's
                                                ///< cert and one of the CAs we have configured.
        bool            tls_check_cert_cn;      //!< Verify that the CN in the server cert matches the host
                                                ///< we passed to mysql_real_connect().
 
        char const      *warnings_str;          //!< Whether we always query the server for additional warnings.
        rlm_sql_mysql_warnings  warnings;       //!< mysql_warning_count() doesn't
                                                //!< appear to work with NDB cluster
} rlm_sql_mysql_t;
 
static conf_parser_t tls_config[] = {
        { FR_CONF_OFFSET_FLAGS("ca_file", CONF_FLAG_FILE_INPUT, rlm_sql_mysql_t, tls_ca_file) },
        { FR_CONF_OFFSET_FLAGS("ca_path", CONF_FLAG_FILE_INPUT, rlm_sql_mysql_t, tls_ca_path) },
        { FR_CONF_OFFSET_FLAGS("certificate_file", CONF_FLAG_FILE_INPUT, rlm_sql_mysql_t, tls_certificate_file) },
        { FR_CONF_OFFSET_FLAGS("private_key_file", CONF_FLAG_FILE_INPUT, rlm_sql_mysql_t, tls_private_key_file) },
        { FR_CONF_OFFSET_FLAGS("crl_file", CONF_FLAG_FILE_INPUT, rlm_sql_mysql_t, tls_crl_file) },
        { FR_CONF_OFFSET_FLAGS("crl_path", CONF_FLAG_FILE_INPUT, rlm_sql_mysql_t, tls_crl_path) },
        /*
         *      MySQL Specific TLS attributes
         */
        { FR_CONF_OFFSET("cipher", rlm_sql_mysql_t, tls_cipher) },
 
        /*
         *      The closest thing we have to these options in other modules is
         *      in rlm_rest.  rlm_ldap has its own bizarre option set.
         *
         *      There, the options can be toggled independently, here they can't
         *      but for consistency we break them out anyway, and warn if the user
         *      has provided an invalid list of flags.
         */
        { FR_CONF_OFFSET("tls_required", rlm_sql_mysql_t, tls_required) },
        { FR_CONF_OFFSET("check_cert", rlm_sql_mysql_t, tls_check_cert) },
        { FR_CONF_OFFSET("check_cert_cn", rlm_sql_mysql_t, tls_check_cert_cn) },
        CONF_PARSER_TERMINATOR
};
 
static const conf_parser_t driver_config[] = {
        { FR_CONF_POINTER("tls", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) tls_config },
 
        { FR_CONF_OFFSET("warnings", rlm_sql_mysql_t, warnings_str), .dflt = "auto" },
        CONF_PARSER_TERMINATOR
};
 
/* Prototypes */
static sql_rcode_t sql_free_result(fr_sql_query_t *, rlm_sql_config_t const *);
 
static int mod_instantiate(module_inst_ctx_t const *mctx)
{
        rlm_sql_mysql_t         *inst = talloc_get_type_abort(mctx->mi->data, rlm_sql_mysql_t);
        int                     warnings;
 
        warnings = fr_table_value_by_str(server_warnings_table, inst->warnings_str, -1);
        if (warnings < 0) {
                ERROR("Invalid warnings value \"%s\", must be yes, no, or auto", inst->warnings_str);
                return -1;
        }
        inst->warnings = (rlm_sql_mysql_warnings)warnings;
 
        if (inst->tls_check_cert && !inst->tls_required) {
                WARN("Implicitly setting tls_required = yes, as tls_check_cert = yes");
                inst->tls_required = true;
        }
        if (inst->tls_check_cert_cn) {
                if (!inst->tls_required) {
                        WARN("Implicitly setting tls_required = yes, as check_cert_cn = yes");
                        inst->tls_required = true;
                }
 
                if (!inst->tls_check_cert) {
                        WARN("Implicitly setting check_cert = yes, as check_cert_cn = yes");
                        inst->tls_check_cert = true;
                }
        }
        return 0;
}
 
static void mod_unload(void)
{
        mysql_library_end();
}
 
static int mod_load(void)
{
        if (mysql_library_init(0, NULL, NULL)) {
                ERROR("libmysql initialisation failed");
 
                return -1;
        }
 
        INFO("libmysql version: %s", mysql_get_client_info());
 
        return 0;
}
 
/** Callback for I/O events in response to mysql_real_connect_start()
 */
static void _sql_connect_io_notify(fr_event_list_t *el, int fd, UNUSED int flags, void *uctx)
{
        rlm_sql_mysql_conn_t    *c = talloc_get_type_abort(uctx, rlm_sql_mysql_conn_t);
 
        fr_event_fd_delete(el, fd, FR_EVENT_FILTER_IO);
 
        if (c->status == 0) goto connected;
        c->status = mysql_real_connect_cont(&c->sock, &c->db, c->status);
 
        /*
         *      If status is not zero, we're still waiting for something.
         *      The event will be fired again when that happens.
         */
        if (c->status != 0) {
                (void) fr_event_fd_insert(c, NULL, c->conn->el, c->fd,
                                          c->status & MYSQL_WAIT_READ ? _sql_connect_io_notify : NULL,
                                          c->status & MYSQL_WAIT_WRITE ? _sql_connect_io_notify : NULL, NULL, c);
                return;
        }
 
connected:
        if (!c->sock) {
                ERROR("MySQL error: %s", mysql_error(&c->db));
                connection_signal_reconnect(c->conn, CONNECTION_FAILED);
                return;
        }
 
        DEBUG2("Connected to database on %s, server version %s, protocol version %i",
               mysql_get_host_info(c->sock),
               mysql_get_server_info(c->sock), mysql_get_proto_info(c->sock));
 
        connection_signal_connected(c->conn);
}
 
static void _sql_connect_query_run(connection_t *conn, UNUSED connection_state_t prev,
                                   UNUSED connection_state_t state, void *uctx)
{
        rlm_sql_t const         *sql = talloc_get_type_abort_const(uctx, rlm_sql_t);
        rlm_sql_mysql_conn_t    *sql_conn = talloc_get_type_abort(conn->h, rlm_sql_mysql_conn_t);
        int                     ret;
        MYSQL_RES               *result;
 
        DEBUG2("Executing \"%s\" on connection %s", sql->config.connect_query, conn->name);
 
        ret = mysql_real_query(sql_conn->sock, sql->config.connect_query, strlen(sql->config.connect_query));
        if (ret != 0) {
                char const *info;
                ERROR("Failed running \"open_query\"");
                info = mysql_info(sql_conn->sock);
                if (info) ERROR("%s", info);
                connection_signal_reconnect(conn, CONNECTION_FAILED);
                return;
        }
 
        /*
         *      These queries should not return any results - but let's be safe
         */
        result = mysql_store_result(sql_conn->sock);
        if (result) mysql_free_result(result);
        while ((mysql_next_result(sql_conn->sock) == 0) &&
               (result = mysql_store_result(sql_conn->sock))) {
                mysql_free_result(result);
        }
}
 
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_mysql_t const   *inst = talloc_get_type_abort(sql->driver_submodule->data, rlm_sql_mysql_t);
        rlm_sql_mysql_conn_t    *c;
        rlm_sql_config_t const  *config = &sql->config;
 
        unsigned long           sql_flags;
        enum mysql_option       ssl_mysql_opt;
        unsigned int            ssl_mode = 0;
        bool                    ssl_mode_isset = false;
 
        MEM(c = talloc_zero(conn, rlm_sql_mysql_conn_t));
        c->conn = conn;
        c->fd = -1;
 
        DEBUG("Starting connect to MySQL server");
 
        mysql_init(&c->db);
 
        /*
         *      If any of the TLS options are set, configure TLS
         *
         *      According to MySQL docs this function always returns 0, so we won't
         *      know if ssl setup succeeded until mysql_real_connect is called below.
         */
        if (inst->tls_ca_file || inst->tls_ca_path ||
            inst->tls_certificate_file || inst->tls_private_key_file) {
                mysql_ssl_set(&(c->db), inst->tls_private_key_file, inst->tls_certificate_file,
                              inst->tls_ca_file, inst->tls_ca_path, inst->tls_cipher);
        }
 
#ifdef MARIADB_BASE_VERSION
        if (inst->tls_required || inst->tls_check_cert || inst->tls_check_cert_cn) {
                ssl_mode_isset = true;
                /**
                 * For MariaDB, It should be true as can be seen in
                 * https://github.com/MariaDB/server/blob/mariadb-5.5.68/sql-common/client.c#L4338
                 */
                ssl_mode = true;
                ssl_mysql_opt = MYSQL_OPT_SSL_VERIFY_SERVER_CERT;
        }
#else
        ssl_mysql_opt = MYSQL_OPT_SSL_MODE;
        if (inst->tls_required) {
                ssl_mode = SSL_MODE_REQUIRED;
                ssl_mode_isset = true;
        }
        if (inst->tls_check_cert) {
                ssl_mode = SSL_MODE_VERIFY_CA;
                ssl_mode_isset = true;
        }
        if (inst->tls_check_cert_cn) {
                ssl_mode = SSL_MODE_VERIFY_IDENTITY;
                ssl_mode_isset = true;
        }
#endif
        if (ssl_mode_isset) mysql_options(&(c->db), ssl_mysql_opt, &ssl_mode);
 
        if (inst->tls_crl_file) mysql_options(&(c->db), MYSQL_OPT_SSL_CRL, inst->tls_crl_file);
        if (inst->tls_crl_path) mysql_options(&(c->db), MYSQL_OPT_SSL_CRLPATH, inst->tls_crl_path);
 
        mysql_options(&(c->db), MYSQL_READ_DEFAULT_GROUP, "freeradius");
 
        /*
         *      We need to know about connection errors, and are capable
         *      of reconnecting automatically.
         */
        {
                bool reconnect = 0;
                mysql_options(&(c->db), MYSQL_OPT_RECONNECT, &reconnect);
        }
 
        sql_flags = CLIENT_MULTI_RESULTS | CLIENT_FOUND_ROWS;
 
#ifdef CLIENT_MULTI_STATEMENTS
        sql_flags |= CLIENT_MULTI_STATEMENTS;
#endif
 
        mysql_options(&c->db, MYSQL_OPT_NONBLOCK, 0);
 
        c->status = mysql_real_connect_start(&c->sock, &c->db,
                                             config->sql_server,
                                             config->sql_login,
                                             config->sql_password,
                                             config->sql_db,
                                             config->sql_port, NULL, sql_flags);
 
        c->fd = mysql_get_socket(&c->db);
 
        if (c->fd <= 0) {
                ERROR("Could't connect to MySQL server %s@%s:%s", config->sql_login,
                      config->sql_server, config->sql_db);
                ERROR("MySQL error: %s", mysql_error(&c->db));
        error:
                talloc_free(c);
                return CONNECTION_STATE_FAILED;
        }
 
        if (c->status == 0) {
                DEBUG2("Connected to database '%s' on %s, server version %s, protocol version %i",
                       config->sql_db, mysql_get_host_info(c->sock),
                       mysql_get_server_info(c->sock), mysql_get_proto_info(c->sock));
                connection_signal_connected(c->conn);
                return CONNECTION_STATE_CONNECTING;
        }
 
        if (fr_event_fd_insert(c, NULL, c->conn->el, c->fd,
                               c->status & MYSQL_WAIT_READ ? _sql_connect_io_notify : NULL,
                               c->status & MYSQL_WAIT_WRITE ? _sql_connect_io_notify : NULL, NULL, c) != 0) goto error;
 
        DEBUG2("Connecting to database '%s' on %s:%d, fd %d",
               config->sql_db, config->sql_server, config->sql_port, c->fd);
 
        *h = c;
 
        if (config->connect_query) connection_add_watch_post(conn, CONNECTION_STATE_CONNECTED,
                                                             _sql_connect_query_run, true, sql);
 
        return CONNECTION_STATE_CONNECTING;
}
 
static void _sql_connection_close(fr_event_list_t *el, void *h, UNUSED void *uctx)
{
        rlm_sql_mysql_conn_t    *c = talloc_get_type_abort(h, rlm_sql_mysql_conn_t);
 
        if (c->fd >= 0) {
                fr_event_fd_delete(el, c->fd, FR_EVENT_FILTER_IO);
                c->fd = -1;
        }
        mysql_close(&c->db);
        c->query_ctx = NULL;
        talloc_free(h);
}
 
/** Analyse the last error that occurred on the socket, and determine an action
 *
 * @param server Socket from which to extract the server error. May be NULL.
 * @param client_errno Error from the client.
 * @return an action for #rlm_sql_t to take.
 */
static sql_rcode_t sql_check_error(MYSQL *server, int client_errno)
{
        int sql_errno = 0;
 
        /*
         *      The client and server error numbers are in the
         *      same numberspace.
         */
        if (server) sql_errno = mysql_errno(server);
        if ((sql_errno == 0) && (client_errno != 0)) sql_errno = client_errno;
 
        if (sql_errno > 0) switch (sql_errno) {
        case CR_SERVER_GONE_ERROR:
        case CR_SERVER_LOST:
                return RLM_SQL_RECONNECT;
 
        case CR_OUT_OF_MEMORY:
        case CR_COMMANDS_OUT_OF_SYNC:
        case CR_UNKNOWN_ERROR:
        default:
                return RLM_SQL_ERROR;
 
        /*
         *      Constraints errors that signify a duplicate, or that we might
         *      want to try an alternative query.
         *
         *      Error constants not found in the 3.23/4.0/4.1 manual page
         *      are checked for.
         *      Other error constants should always be available.
         */
        case ER_DUP_UNIQUE:                     /* Can't write, because of unique constraint, to table '%s'. */
        case ER_DUP_KEY:                        /* Can't write; duplicate key in table '%s' */
 
        case ER_DUP_ENTRY:                      /* Duplicate entry '%s' for key %d. */
        case ER_NO_REFERENCED_ROW:              /* Cannot add or update a child row: a foreign key constraint fails */
        case ER_ROW_IS_REFERENCED:              /* Cannot delete or update a parent row: a foreign key constraint fails */
#ifdef ER_FOREIGN_DUPLICATE_KEY
        case ER_FOREIGN_DUPLICATE_KEY:          /* Upholding foreign key constraints for table '%s', entry '%s', key %d would lead to a duplicate entry. */
#endif
#ifdef ER_DUP_ENTRY_WITH_KEY_NAME
        case ER_DUP_ENTRY_WITH_KEY_NAME:        /* Duplicate entry '%s' for key '%s' */
#endif
#ifdef ER_NO_REFERENCED_ROW_2
        case ER_NO_REFERENCED_ROW_2:
#endif
#ifdef ER_ROW_IS_REFERENCED_2
        case ER_ROW_IS_REFERENCED_2:
#endif
                return RLM_SQL_ALT_QUERY;
 
        /*
         *      Constraints errors that signify an invalid query
         *      that can never succeed.
         */
        case ER_BAD_NULL_ERROR:                 /* Column '%s' cannot be null */
        case ER_NON_UNIQ_ERROR:                 /* Column '%s' in %s is ambiguous */
                return RLM_SQL_QUERY_INVALID;
 
        }
 
        return RLM_SQL_OK;
}
 
static sql_rcode_t sql_store_result(rlm_sql_mysql_conn_t *conn, UNUSED rlm_sql_config_t const *config)
{
        sql_rcode_t rcode;
        int ret;
 
retry_store_result:
        conn->result = mysql_store_result(conn->sock);
        if (!conn->result) {
                rcode = sql_check_error(conn->sock, 0);
                if (rcode != RLM_SQL_OK) return rcode;
                ret = mysql_next_result(conn->sock);
                if (ret == 0) {
                        /* there are more results */
                        goto retry_store_result;
                } else if (ret > 0) return sql_check_error(NULL, ret);
                /* ret == -1 signals no more results */
        }
        return RLM_SQL_OK;
}
 
static int sql_num_rows(fr_sql_query_t *query_ctx, UNUSED rlm_sql_config_t const *config)
{
        rlm_sql_mysql_conn_t *conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_mysql_conn_t);
 
        if (conn->result) return mysql_num_rows(conn->result);
 
        return 0;
}
 
static sql_rcode_t sql_fields(char const **out[], fr_sql_query_t *query_ctx, UNUSED rlm_sql_config_t const *config)
{
        rlm_sql_mysql_conn_t *conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_mysql_conn_t);
 
        unsigned int    fields, i;
        MYSQL_FIELD     *field_info;
        char const      **names;
 
        /*
         *      Use our internal function to abstract out the API call.
         *      Different versions of SQL use different functions,
         *      and some don't like NULL pointers.
         */
        fields = mysql_field_count(conn->sock);
        if (fields == 0) return RLM_SQL_ERROR;
 
        /*
         *      https://bugs.mysql.com/bug.php?id=32318
         *      Hints that we don't have to free field_info.
         */
        field_info = mysql_fetch_fields(conn->result);
        if (!field_info) return RLM_SQL_ERROR;
 
        MEM(names = talloc_array(query_ctx, char const *, fields));
 
        for (i = 0; i < fields; i++) names[i] = field_info[i].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_mysql_conn_t    *conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_mysql_conn_t);
        MYSQL_ROW               row;
        int                     ret;
        unsigned int            num_fields, i;
        unsigned long           *field_lens;
 
        /*
         *  Check pointer before de-referencing it.
         */
        if (!conn->result) {
                query_ctx->rcode = RLM_SQL_RECONNECT;
                RETURN_MODULE_FAIL;
        }
 
        TALLOC_FREE(query_ctx->row);            /* Clear previous row set */
 
retry_fetch_row:
        row = mysql_fetch_row(conn->result);
        if (!row) {
                query_ctx->rcode = sql_check_error(conn->sock, 0);
                if (query_ctx->rcode != RLM_SQL_OK) RETURN_MODULE_FAIL;
 
                mysql_free_result(conn->result);
                conn->result = NULL;
 
                ret = mysql_next_result(conn->sock);
                if (ret == 0) {
                        /* there are more results */
                        if ((sql_store_result(conn, &query_ctx->inst->config) == 0) && (conn->result != NULL)) {
                                goto retry_fetch_row;
                        }
                } else if (ret > 0) {
                        query_ctx->rcode = sql_check_error(NULL, ret);
                        if (query_ctx->rcode == RLM_SQL_OK) RETURN_MODULE_OK;
                        RETURN_MODULE_FAIL;
                }
                /* If ret is -1 then there are no more rows */
 
                query_ctx->rcode = RLM_SQL_NO_MORE_ROWS;
                RETURN_MODULE_OK;
        }
 
        num_fields = mysql_field_count(conn->sock);
        if (!num_fields) {
                query_ctx->rcode = RLM_SQL_NO_MORE_ROWS;
                RETURN_MODULE_OK;
        }
 
        field_lens = mysql_fetch_lengths(conn->result);
 
        MEM(query_ctx->row = talloc_zero_array(query_ctx, char *, num_fields + 1));
        for (i = 0; i < num_fields; i++) {
                MEM(query_ctx->row[i] = talloc_bstrndup(query_ctx->row, row[i], field_lens[i]));
        }
 
        query_ctx->rcode = RLM_SQL_OK;
        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_mysql_conn_t *conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_mysql_conn_t);
 
        if (conn->result) {
                mysql_free_result(conn->result);
                conn->result = NULL;
        }
        TALLOC_FREE(query_ctx->row);
 
        return RLM_SQL_OK;
}
 
/** Retrieves any warnings associated with the last query
 *
 * MySQL stores a limited number of warnings associated with the last query
 * executed. These can be very useful in diagnosing issues, or in some cases
 * working around bugs in MySQL which causes it to return the wrong error.
 *
 * @note Caller should free any memory allocated in ctx (talloc_free_children()).
 *
 * @param ctx to allocate temporary error buffers in.
 * @param out Array of sql_log_entrys to fill.
 * @param outlen Length of out array.
 * @param conn MySQL connection the query was run on.
 * @param config rlm_sql config.
 * @return
 *      - Number of errors written to the #sql_log_entry_t array.
 *      - -1 on failure.
 */
static size_t sql_warnings(TALLOC_CTX *ctx, sql_log_entry_t out[], size_t outlen,
                           rlm_sql_mysql_conn_t *conn, UNUSED rlm_sql_config_t const *config)
{
        MYSQL_RES               *result;
        MYSQL_ROW               row;
        unsigned int            num_fields;
        size_t                  i = 0;
 
        if (outlen == 0) return 0;
 
        /*
         *      Retrieve any warnings associated with the previous query
         *      that were left lingering on the server.
         */
        if (mysql_query(conn->sock, "SHOW WARNINGS") != 0) return -1;
        result = mysql_store_result(conn->sock);
        if (!result) return -1;
 
        /*
         *      Fields should be [0] = Level, [1] = Code, [2] = Message
         */
        num_fields = mysql_field_count(conn->sock);
        if (num_fields < 3) {
                WARN("Failed retrieving warnings, expected 3 fields got %u", num_fields);
                mysql_free_result(result);
 
                return -1;
        }
 
        while ((row = mysql_fetch_row(result))) {
                char *msg = NULL;
                fr_log_type_t type;
 
                /*
                 *      Translate the MySQL log level into our internal
                 *      log levels, so they get colourised correctly.
                 */
                if (strcasecmp(row[0], "warning") == 0) type = L_WARN;
                else if (strcasecmp(row[0], "note") == 0) type = L_DBG;
                else type = L_ERR;
 
                msg = talloc_typed_asprintf(ctx, "%s: %s", row[1], row[2]);
                out[i].type = type;
                out[i].msg = msg;
                if (++i == outlen) break;
        }
 
        mysql_free_result(result);
 
        return i;
}
 
/** Retrieves any errors associated with the query context
 *
 * @note Caller should free any memory allocated in ctx (talloc_free_children()).
 *
 * @param ctx to allocate temporary error buffers in.
 * @param out Array of sql_log_entrys to fill.
 * @param outlen Length of out array.
 * @param query_ctx Query context to retrieve error for.
 * @param config rlm_sql config.
 * @return number of errors written to the #sql_log_entry_t array.
 */
static size_t sql_error(TALLOC_CTX *ctx, sql_log_entry_t out[], size_t outlen,
                        fr_sql_query_t *query_ctx, rlm_sql_config_t const *config)
{
        rlm_sql_mysql_t const   *inst = talloc_get_type_abort_const(query_ctx->inst->driver_submodule->data, rlm_sql_mysql_t);
        rlm_sql_mysql_conn_t    *conn;
        char const              *error;
        size_t                  i = 0;
 
        if (!query_ctx->tconn) return 0;
        conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_mysql_conn_t);
 
        fr_assert(outlen > 0);
 
        error = mysql_error(conn->sock);
 
        /*
         *      Grab the error now in case it gets cleared on the next operation.
         */
        if (error && (error[0] != '\0')) {
                error = talloc_typed_asprintf(ctx, "ERROR %u (%s): %s", mysql_errno(conn->sock), error,
                                              mysql_sqlstate(conn->sock));
        }
 
        /*
         *      Don't attempt to get errors from the server, if the last error
         *      was that the server was unavailable.
         */
        if ((outlen > 1) && (sql_check_error(conn->sock, 0) != RLM_SQL_RECONNECT)) {
                size_t ret;
                unsigned int msgs;
 
                switch (inst->warnings) {
                case SERVER_WARNINGS_AUTO:
                        /*
                         *      Check to see if any warnings can be retrieved from the server.
                         */
                        msgs = mysql_warning_count(conn->sock);
                        if (msgs == 0) {
                                DEBUG3("No additional diagnostic info on server");
                                break;
                        }
 
                FALL_THROUGH;
                case SERVER_WARNINGS_YES:
                        ret = sql_warnings(ctx, out, outlen - 1, conn, config);
                        if (ret > 0) i += ret;
                        break;
 
                case SERVER_WARNINGS_NO:
                        break;
 
                default:
                        fr_assert(0);
                }
        }
 
        if (error) {
                out[i].type = L_ERR;
                out[i].msg = error;
        }
        i++;
 
        return i;
}
 
/** Finish query
 *
 * As a single SQL statement may return multiple results
 * sets, (for example stored procedures) it is necessary to check
 * whether more results exist and process them in turn if so.
 *
 */
static sql_rcode_t sql_finish_query(fr_sql_query_t *query_ctx, rlm_sql_config_t const *config)
{
        rlm_sql_mysql_conn_t    *conn;
        int                     ret;
        MYSQL_RES               *result;
 
        /*
         *      If the query is not in a state which would return results, then do nothing.
         */
        if (query_ctx->treq && !(query_ctx->treq->state &
            (TRUNK_REQUEST_STATE_SENT | TRUNK_REQUEST_STATE_REAPABLE | TRUNK_REQUEST_STATE_COMPLETE))) return RLM_SQL_OK;
 
        /*
         *      If the connection doesn't exist there's nothing to do
         */
        if (!query_ctx->tconn || !query_ctx->tconn->conn || !query_ctx->tconn->conn->h) return RLM_SQL_ERROR;
 
        conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_mysql_conn_t);
 
        /*
         *      If the connection is not active, then all that we can do is free any stored results
         */
        if (query_ctx->tconn->conn->state != CONNECTION_STATE_CONNECTED) {
                sql_free_result(query_ctx, config);
                return RLM_SQL_OK;
        }
 
        /*
         *      If there's no result associated with the
         *      connection handle, assume the first result in the
         *      result set hasn't been retrieved.
         *
         *      MySQL docs says there's no performance penalty for
         *      calling mysql_store_result for queries which don't
         *      return results.
         */
        if (conn->result == NULL) {
                result = mysql_store_result(conn->sock);
                if (result) mysql_free_result(result);
        /*
         *      ...otherwise call sql_free_result to free an
         *      already stored result.
         */
        } else {
                sql_free_result(query_ctx, config);     /* sql_free_result sets conn->result to NULL */
        }
 
        /*
         *      Drain any other results associated with the handle
         *
         *      mysql_next_result advances the result cursor so that
         *      the next call to mysql_store_result will retrieve
         *      the next result from the server.
         *
         *      Unfortunately this really does appear to be the
         *      only way to return the handle to a consistent state.
         */
        while (((ret = mysql_next_result(conn->sock)) == 0) &&
               (result = mysql_store_result(conn->sock))) {
                mysql_free_result(result);
        }
        if (ret > 0) return sql_check_error(NULL, ret);
 
        return RLM_SQL_OK;
}
 
static int sql_affected_rows(fr_sql_query_t *query_ctx, UNUSED rlm_sql_config_t const *config)
{
        rlm_sql_mysql_conn_t *conn = talloc_get_type_abort(query_ctx->tconn->conn->h, rlm_sql_mysql_conn_t);
 
        return mysql_affected_rows(conn->sock);
}
 
static size_t sql_escape_func(UNUSED request_t *request, char *out, size_t outlen, char const *in, void *arg)
{
        size_t                  inlen;
        connection_t            *c = talloc_get_type_abort(arg, connection_t);
        rlm_sql_mysql_conn_t    *conn = talloc_get_type_abort(c->h, rlm_sql_mysql_conn_t);
 
        /* Check for potential buffer overflow */
        inlen = strlen(in);
        if ((inlen * 2 + 1) > outlen) return 0;
        /* Prevent integer overflow */
        if ((inlen * 2 + 1) <= inlen) return 0;
 
        return mysql_real_escape_string(&conn->db, out, in, inlen);
}
 
static void sql_conn_writable(UNUSED fr_event_list_t *el, UNUSED int fd, UNUSED int flags, void *uctx)
{
        trunk_connection_t      *tconn = talloc_get_type_abort(uctx, trunk_connection_t);
        trunk_connection_signal_writable(tconn);
}
 
static void sql_conn_readable(UNUSED fr_event_list_t *el, UNUSED int fd, UNUSED int flags, void *uctx)
{
        trunk_connection_t      *tconn = talloc_get_type_abort(uctx, trunk_connection_t);
        trunk_connection_signal_readable(tconn);
}
 
static void sql_conn_error(UNUSED fr_event_list_t *el, UNUSED int fd, UNUSED int flags, int fd_errno, void *uctx)
{
        trunk_connection_t      *tconn = talloc_get_type_abort(uctx, trunk_connection_t);
        ERROR("%s - Connection failed: %s", tconn->conn->name, fr_syserror(fd_errno));
        connection_signal_reconnect(tconn->conn, CONNECTION_FAILED);
}
 
/** Allocate an SQL trunk connection
 *
 * @param[in] tconn             Trunk handle.
 * @param[in] el                Event list which will be used for I/O and timer events.
 * @param[in] conn_conf         Configuration of the connection.
 * @param[in] log_prefix        What to prefix log messages with.
 * @param[in] uctx              User context passed to trunk_alloc.
 */
static connection_t *sql_trunk_connection_alloc(trunk_connection_t *tconn, fr_event_list_t *el,
                                                   connection_conf_t const *conn_conf,
                                                   char const *log_prefix, void *uctx)
{
        connection_t            *conn;
        rlm_sql_thread_t        *thread = talloc_get_type_abort(uctx, rlm_sql_thread_t);
 
        conn = connection_alloc(tconn, el,
                                   &(connection_funcs_t){
                                        .init = _sql_connection_init,
                                        .close = _sql_connection_close
                                   },
                                   conn_conf, log_prefix, thread->inst);
        if (!conn) {
                PERROR("Failed allocating state handler for new SQL connection");
                return NULL;
        }
 
        return conn;
}
 
static void sql_trunk_connection_notify(trunk_connection_t *tconn, connection_t *conn,
                                        fr_event_list_t *el,
                                        trunk_connection_event_t notify_on, UNUSED void *uctx)
{
        rlm_sql_mysql_conn_t    *sql_conn = talloc_get_type_abort(conn->h, rlm_sql_mysql_conn_t);
        fr_event_fd_cb_t        read_fn = NULL, write_fn = NULL;
 
        switch (notify_on) {
        case TRUNK_CONN_EVENT_NONE:
                fr_event_fd_delete(el, sql_conn->fd, FR_EVENT_FILTER_IO);
                return;
 
        case TRUNK_CONN_EVENT_READ:
                read_fn = sql_conn_readable;
                break;
 
        case TRUNK_CONN_EVENT_WRITE:
                write_fn = sql_conn_writable;
                break;
 
        case TRUNK_CONN_EVENT_BOTH:
                read_fn = sql_conn_readable;
                write_fn = sql_conn_writable;
                break;
        }
 
        if (fr_event_fd_insert(sql_conn, NULL, el, sql_conn->fd, read_fn, write_fn, sql_conn_error, tconn) < 0) {
                PERROR("Failed inserting FD event");
                trunk_connection_signal_reconnect(tconn, CONNECTION_FAILED);
        }
}
 
static void sql_trunk_request_mux(UNUSED fr_event_list_t *el, trunk_connection_t *tconn,
                                  connection_t *conn, UNUSED void *uctx)
{
        rlm_sql_mysql_conn_t    *sql_conn = talloc_get_type_abort(conn->h, rlm_sql_mysql_conn_t);
        request_t               *request;
        trunk_request_t *treq;
        fr_sql_query_t          *query_ctx;
        char const              *info;
        int                     err;
 
        if (trunk_connection_pop_request(&treq, tconn) != 0) return;
        if (!treq) return;
 
        query_ctx = talloc_get_type_abort(treq->preq, fr_sql_query_t);
        request = query_ctx->request;
 
        /*
         *      Each of the MariaDB async "start" calls returns a non-zero value
         *      if they are waiting on I/O.
         *      A return value of zero means that the operation completed.
         */
 
        switch (query_ctx->status) {
        case SQL_QUERY_PREPARED:
                ROPTIONAL(RDEBUG2, DEBUG2, "Executing query: %s", query_ctx->query_str);
                sql_conn->status = mysql_real_query_start(&err, sql_conn->sock, query_ctx->query_str, strlen(query_ctx->query_str));
                query_ctx->tconn = tconn;
 
                if (sql_conn->status) {
                        ROPTIONAL(RDEBUG3, DEBUG3, "Waiting for IO");
                        query_ctx->status = SQL_QUERY_SUBMITTED;
                        sql_conn->query_ctx = query_ctx;
                        trunk_request_signal_sent(treq);
                        return;
                }
 
                if (err) {
                        /*
                         *      Need to check what kind of error this is - it may
                         *      be a unique key conflict, we run the next query.
                         */
                        info = mysql_info(sql_conn->sock);
                        query_ctx->rcode = sql_check_error(sql_conn->sock, 0);
                        if (info) ERROR("%s", info);
                        switch (query_ctx->rcode) {
                        case RLM_SQL_OK:
                        case RLM_SQL_ALT_QUERY:
                                break;
 
                        default:
                                query_ctx->status = SQL_QUERY_FAILED;
                                trunk_request_signal_fail(treq);
                                return;
                        }
                }
                query_ctx->status = SQL_QUERY_RETURNED;
 
                break;
 
        case SQL_QUERY_RETURNED:
                ROPTIONAL(RDEBUG2, DEBUG2, "Fetching results");
                fr_assert(query_ctx->tconn == tconn);
                sql_conn->status = mysql_store_result_start(&sql_conn->result, sql_conn->sock);
 
                if (sql_conn->status) {
                        ROPTIONAL(RDEBUG3, DEBUG3, "Waiting for IO");
                        query_ctx->status = SQL_QUERY_FETCHING_RESULTS;
                        sql_conn->query_ctx = query_ctx;
                        trunk_request_signal_sent(treq);
                        return;
                }
                query_ctx->status = SQL_QUERY_RESULTS_FETCHED;
 
                break;
 
        default:
                /*
                 *      The request outstanding on this connection returned
                 *      immediately, so we are not actually waiting for I/O.
                 */
                return;
        }
 
        /*
         *      The current request is not waiting for I/O so the request can run
         */
        ROPTIONAL(RDEBUG3, DEBUG3, "Got immediate response");
        trunk_request_signal_reapable(treq);
        if (request) unlang_interpret_mark_runnable(request);
}
 
static void sql_trunk_request_demux(UNUSED fr_event_list_t *el, UNUSED trunk_connection_t *tconn,
                                    connection_t *conn, UNUSED void *uctx)
{
        rlm_sql_mysql_conn_t    *sql_conn = talloc_get_type_abort(conn->h, rlm_sql_mysql_conn_t);
        fr_sql_query_t          *query_ctx;
        char const              *info;
        int                     err = 0;
        request_t               *request;
 
        /*
         *      Lookup the outstanding SQL query for this connection.
         *      There will only ever be one per tconn.
         */
        query_ctx = sql_conn->query_ctx;
 
        /*
         *      No outstanding query on this connection.
         *      Should not happen, but added for safety.
         */
        if (unlikely(!query_ctx)) return;
 
        switch (query_ctx->status) {
        case SQL_QUERY_SUBMITTED:
                sql_conn->status = mysql_real_query_cont(&err, sql_conn->sock, sql_conn->status);
                break;
 
        case SQL_QUERY_FETCHING_RESULTS:
                sql_conn->status = mysql_store_result_cont(&sql_conn->result, sql_conn->sock, sql_conn->status);
                break;
 
        default:
                /*
                 *      The request outstanding on this connection returned
                 *      immediately, so we are not actually waiting for I/O.
                 */
                return;
        }
 
        /*
         *      Are we still waiting for any further I/O?
         */
        if (sql_conn->status != 0) return;
 
        sql_conn->query_ctx = NULL;
 
        switch (query_ctx->status) {
        case SQL_QUERY_SUBMITTED:
                query_ctx->status = SQL_QUERY_RETURNED;
                break;
 
        case SQL_QUERY_FETCHING_RESULTS:
                query_ctx->status = SQL_QUERY_RESULTS_FETCHED;
                break;
 
        default:
                fr_assert(0);
        }
 
        request = query_ctx->request;
        if (request) unlang_interpret_mark_runnable(request);
 
        if (err) {
                info = mysql_info(sql_conn->sock);
                query_ctx->rcode = sql_check_error(sql_conn->sock, 0);
                if (info) ROPTIONAL(RERROR, ERROR, "%s", info);
                return;
        }
 
        query_ctx->rcode = RLM_SQL_OK;
}
 
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_mysql_conn_t    *sql_conn = talloc_get_type_abort(conn->h, rlm_sql_mysql_conn_t);
 
        if (!query_ctx->treq) return;
        if (reason != TRUNK_CANCEL_REASON_SIGNAL) return;
        if (sql_conn->query_ctx == query_ctx) sql_conn->query_ctx = NULL;
}
 
static void sql_request_cancel_mux(UNUSED fr_event_list_t *el, trunk_connection_t *tconn,
                                   connection_t *conn, UNUSED void *uctx)
{
        trunk_request_t *treq;
 
        /*
         *      The MariaDB non-blocking API doesn't have any cancellation functions -
         *      rather you are expected to close the connection.
         */
        if ((trunk_connection_pop_cancellation(&treq, tconn)) == 0) {
                trunk_request_signal_cancel_complete(treq);
                connection_signal_reconnect(conn, CONNECTION_FAILED);
        }
}
 
static void sql_request_fail(request_t *request, void *preq, UNUSED void *rctx,
                             UNUSED trunk_request_state_t state, UNUSED void *uctx)
{
        fr_sql_query_t          *query_ctx = talloc_get_type_abort(preq, fr_sql_query_t);
 
        query_ctx->treq = NULL;
        query_ctx->rcode = RLM_SQL_ERROR;
 
        if (request) unlang_interpret_mark_runnable(request);
}
 
static unlang_action_t sql_query_resume(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);
 
        if (query_ctx->rcode == RLM_SQL_OK) RETURN_MODULE_OK;
        RETURN_MODULE_FAIL;
}
 
static unlang_action_t sql_select_query_resume(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);
 
        if (query_ctx->rcode != RLM_SQL_OK) RETURN_MODULE_FAIL;
 
        if (query_ctx->status == SQL_QUERY_RETURNED) {
                trunk_request_requeue(query_ctx->treq);
 
                if (unlang_function_repeat_set(request, sql_select_query_resume) < 0) {
                        query_ctx->rcode = RLM_SQL_ERROR;
                        RETURN_MODULE_FAIL;
                }
 
                return UNLANG_ACTION_YIELD;
        }
 
        RETURN_MODULE_OK;
}
 
/** Allocate the argument used for the SQL escape function
 *
 * In this case, a dedicated connection to allow the escape
 * function to have access to server side parameters, though
 * no packets ever flow after the connection is made.
 */
static void *sql_escape_arg_alloc(TALLOC_CTX *ctx, fr_event_list_t *el, void *uctx)
{
        rlm_sql_t const *inst = talloc_get_type_abort(uctx, rlm_sql_t);
        connection_t *conn;
 
        conn = connection_alloc(ctx, el,
                                    &(connection_funcs_t){
                                        .init = _sql_connection_init,
                                        .close = _sql_connection_close,
                                    },
                                    inst->config.trunk_conf.conn_conf,
                                    inst->name, inst);
 
        if (!conn) {
                PERROR("Failed allocating state handler for SQL escape connection");
                return NULL;
        }
 
        connection_signal_init(conn);
        return conn;
}
 
static void sql_escape_arg_free(void *uctx)
{
        connection_t    *conn = talloc_get_type_abort(uctx, connection_t);
        connection_signal_halt(conn);
}
 
/* Exported to rlm_sql */
extern rlm_sql_driver_t rlm_sql_mysql;
rlm_sql_driver_t rlm_sql_mysql = {
        .common = {
                .name                           = "sql_mysql",
                .magic                          = MODULE_MAGIC_INIT,
                .inst_size                      = sizeof(rlm_sql_mysql_t),
                .onload                         = mod_load,
                .unload                         = mod_unload,
                .config                         = driver_config,
                .instantiate                    = mod_instantiate
        },
        .flags                          = RLM_SQL_RCODE_FLAGS_ALT_QUERY,
        .sql_query_resume               = sql_query_resume,
        .sql_select_query_resume        = sql_select_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,
        .sql_escape_func                = sql_escape_func,
        .sql_escape_arg_alloc           = sql_escape_arg_alloc,
        .sql_escape_arg_free            = sql_escape_arg_free,
        .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_demux          = sql_trunk_request_demux,
                .request_cancel_mux     = sql_request_cancel_mux,
                .request_cancel         = sql_request_cancel,
                .request_fail           = sql_request_fail,
        }
};