connection.c

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/*
 *   This program is is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or (at
 *   your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: a64332c312ea253fe014ca336fab6a3c6f5dd2fb $
 * @file lib/ldap/connection.c
 * @brief Asynchronous connection management functions for LDAP.
 *
 * @copyright 2017 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 */
RCSID("$Id: a64332c312ea253fe014ca336fab6a3c6f5dd2fb $")
 
USES_APPLE_DEPRECATED_API
 
#include <freeradius-devel/ldap/base.h>
#include <freeradius-devel/util/debug.h>
 
/*
 *      Lookup of libldap result message types to meaningful strings
 */
static char const *ldap_msg_types[UINT8_MAX] = {
        [LDAP_RES_BIND]                 = "bind response",
        [LDAP_RES_SEARCH_ENTRY]         = "search entry",
        [LDAP_RES_SEARCH_REFERENCE]     = "search reference",
        [LDAP_RES_SEARCH_RESULT]        = "search result",
        [LDAP_RES_MODIFY]               = "modify response",
        [LDAP_RES_ADD]                  = "add response",
        [LDAP_RES_DELETE]               = "delete response",
        [LDAP_RES_MODDN]                = "modify dn response",
        [LDAP_RES_COMPARE]              = "compare response",
        [LDAP_RES_EXTENDED]             = "extended response",
        [LDAP_RES_INTERMEDIATE]         = "intermediate response"
};
 
 
/** Allocate and configure a new connection
 *
 * Configures both our ldap handle, and libldap's handle.
 *
 * This can be used by async code and async code as no attempt is made to connect
 * to the LDAP server.  An attempt will only be made if ldap_start_tls* or ldap_bind*
 * functions are called.
 *
 * If called on an #fr_ldap_connection_t which has already been initialised, will
 * clear any memory allocated to the connection, unbind the ldap handle, and reinitialise
 * everything.
 *
 * @param[in] c         to configure.
 * @param[in] config    to apply.
 * @return
 *      - 0 on success.
 *      - -1 on error.
 */
int fr_ldap_connection_configure(fr_ldap_connection_t *c, fr_ldap_config_t const *config)
{
        LDAP    *handle = NULL;
        int     ldap_errno, ldap_version, keepalive, probes, is_server;
 
        fr_assert(config->server);
 
        ldap_errno = ldap_initialize(&handle, config->server);
        if (ldap_errno != LDAP_SUCCESS) {
                ERROR("ldap_initialize failed: %s", ldap_err2string(ldap_errno));
        error:
                return -1;
        }
 
        DEBUG3("New connection %p libldap handle %p", c, handle);
 
        c->config = config;
        c->handle = handle;
 
        /*
         *      We now have a connection structure, but no actual connection.
         *
         *      Set a bunch of LDAP options, using common code.
         */
#define do_ldap_option(_option, _name, _value) \
        if (ldap_set_option(c->handle, _option, _value) != LDAP_OPT_SUCCESS) do { \
                ldap_get_option(c->handle, LDAP_OPT_ERROR_NUMBER, &ldap_errno); \
                ERROR("Failed setting connection option %s: %s", _name, \
                      (ldap_errno != LDAP_SUCCESS) ? ldap_err2string(ldap_errno) : "Unknown error"); \
                goto error;\
        } while (0)
 
DIAG_OFF(unused-macros)
#define maybe_ldap_option(_option, _name, _value) \
        if (_value) do_ldap_option(_option, _name, _value)
DIAG_ON(unused-macros)
 
        /*
         *      Leave "dereference" unset to use the OpenLDAP default.
         */
        if (config->dereference_str) do_ldap_option(LDAP_OPT_DEREF, "dereference", &(config->dereference));
 
        /*
         *      We handle our own referral chasing as there is no way to
         *      get the fd for a referred query.
         */
        do_ldap_option(LDAP_OPT_REFERRALS, "chase_referrals", LDAP_OPT_OFF);
 
        /*
         *      A value of zero results in an handle configuration failure.
         *
         *      When most people specify zero they mean infinite.
         *
         *      libldap requires tv_sec to be -1 to mean that.
         */
        do_ldap_option(LDAP_OPT_NETWORK_TIMEOUT, "net_timeout",
                       (fr_time_delta_ispos(config->net_timeout) ?
                                &fr_time_delta_to_timeval(config->net_timeout) :
                                &(struct timeval) { .tv_sec = -1, .tv_usec = 0 }));
 
        do_ldap_option(LDAP_OPT_TIMELIMIT, "srv_timelimit", &fr_time_delta_to_timeval(config->srv_timelimit));
 
        ldap_version = LDAP_VERSION3;
        do_ldap_option(LDAP_OPT_PROTOCOL_VERSION, "ldap_version", &ldap_version);
 
        keepalive = fr_time_delta_to_sec(config->keepalive_idle);
        do_ldap_option(LDAP_OPT_X_KEEPALIVE_IDLE, "keepalive_idle", &keepalive);
 
        probes = config->keepalive_probes;
        do_ldap_option(LDAP_OPT_X_KEEPALIVE_PROBES, "keepalive_probes", &probes);
 
        keepalive = fr_time_delta_to_sec(config->keepalive_interval);
        do_ldap_option(LDAP_OPT_X_KEEPALIVE_INTERVAL, "keepalive_interval", &keepalive);
 
        /*
         *      Set all of the TLS options
         */
        if (config->tls_mode) do_ldap_option(LDAP_OPT_X_TLS, "tls_mode", &(config->tls_mode));
 
        maybe_ldap_option(LDAP_OPT_X_TLS_CACERTFILE, "ca_file", config->tls_ca_file);
        maybe_ldap_option(LDAP_OPT_X_TLS_CACERTDIR, "ca_path", config->tls_ca_path);
 
        /*
         *      Set certificate options
         */
        maybe_ldap_option(LDAP_OPT_X_TLS_CERTFILE, "certificate_file", config->tls_certificate_file);
        maybe_ldap_option(LDAP_OPT_X_TLS_KEYFILE, "private_key_file", config->tls_private_key_file);
 
        if (config->tls_require_cert_str) {
                do_ldap_option(LDAP_OPT_X_TLS_REQUIRE_CERT, "require_cert", &config->tls_require_cert);
        }
 
        if (config->tls_min_version_str) {
                do_ldap_option(LDAP_OPT_X_TLS_PROTOCOL_MIN, "tls_min_version", &config->tls_min_version);
        }
 
        /*
         *      Counter intuitively the TLS context appears to need to be initialised
         *      after all the TLS options are set on the handle.
         */
 
        /* Always use the new TLS configuration context */
        is_server = 0;
        do_ldap_option(LDAP_OPT_X_TLS_NEWCTX, "new TLS context", &is_server);
 
        if (config->sasl_secprops) do_ldap_option(LDAP_OPT_X_SASL_SECPROPS, "sasl_secprops", config->sasl_secprops);
 
        if (config->start_tls) {
                if (config->port == 636) {
                        WARN("Told to Start TLS on LDAPS port this will probably fail, please correct the "
                             "configuration");
                }
        }
 
        return 0;
}
 
/** Free the handle, closing the connection to ldap
 *
 * @param[in] el        UNUSED.
 * @param[in] h         to close.
 * @param[in] uctx      Connection config and handle.
 */
static void _ldap_connection_close(fr_event_list_t *el, void *h, UNUSED void *uctx)
{
        fr_ldap_connection_t *c = talloc_get_type_abort(h, fr_ldap_connection_t);
 
        /*
         *      Explicitly remove the file descriptor event
         *
         *      Even if the fr_ldap_connection_t has outstanding
         *      queries, we still don't want its fd in the event loop.
         */
        if (c->fd >= 0) {
                fr_event_fd_delete(el, c->fd, FR_EVENT_FILTER_IO);
                c->fd = -1;
        }
 
        talloc_free(h);
}
 
/** Close and delete a connection
 *
 * Unbinds the LDAP connection, informing the server and freeing any memory, then releases the memory used by the
 * connection handle.
 *
 * @param[in] c         to destroy.
 * @return always indicates success.
 */
static int _ldap_connection_free(fr_ldap_connection_t *c)
{
        /*
         *      If there are any pending queries, don't free
         */
        if (((c->queries) && (fr_rb_num_elements(c->queries) > 0)) || (fr_dlist_num_elements(&c->refs) > 0)) return -1;
 
        talloc_free_children(c);        /* Force inverted free order */
 
        if (c->handle) {
                LDAPControl     *our_serverctrls[LDAP_MAX_CONTROLS];
                LDAPControl     *our_clientctrls[LDAP_MAX_CONTROLS];
 
                fr_ldap_control_merge(our_serverctrls, our_clientctrls,
                                      NUM_ELEMENTS(our_serverctrls),
                                      NUM_ELEMENTS(our_clientctrls),
                                      c, NULL, NULL);
 
                DEBUG3("Closing connection %p libldap handle %p", c->handle, c);
                ldap_unbind_ext(c->handle, our_serverctrls, our_clientctrls);   /* Same code as ldap_unbind_ext_s */
        }
 
        fr_ldap_control_clear(c);
 
        return 0;
}
 
/** Allocate our ldap connection handle layer
 *
 * This is using handles outside of the connection state machine.
 *
 * @param[in] ctx to allocate connection handle in.
 * @return
 *      - A new unbound/unconfigured connection handle on success.
 *        Call f#r_ldap_connection_configure next.
 *      - NULL on OOM.
 */
fr_ldap_connection_t *fr_ldap_connection_alloc(TALLOC_CTX *ctx)
{
        fr_ldap_connection_t *c;
 
        /*
         *      Allocate memory for the handle.
         */
        c = talloc_zero(ctx, fr_ldap_connection_t);
        if (!c) return NULL;
 
        talloc_set_destructor(c, _ldap_connection_free);
 
        /*
         *      Ensure the fd is invalid to start with, preventing
         *      attempts to remove fd events if the server is shut down
         *      before the LDAP connection is established
         */
        c->fd = -1;
 
        return c;
}
 
/** Watcher for LDAP connections being closed
 *
 * If there are any outstanding queries on the connection then
 * re-parent the connection to the NULL ctx so that it remains
 * until all the queries have been dealt with.
 */
static void _ldap_connection_close_watch(fr_connection_t *conn, UNUSED fr_connection_state_t prev,
                                         UNUSED fr_connection_state_t state, void *uctx)
{
        fr_ldap_connection_t    *ldap_conn = talloc_get_type_abort(uctx, fr_ldap_connection_t);
 
        if ((fr_rb_num_elements(ldap_conn->queries) == 0) && (fr_dlist_num_elements(&ldap_conn->refs) == 0)) return;
 
        talloc_reparent(conn, NULL, ldap_conn);
        ldap_conn->conn = NULL;
}
 
/** (Re-)Initialises the libldap side of the connection handle
 *
 *  The first ldap state transition is either:
 *
 *     init -> start tls
 *  or
 *     init -> bind
 *
 *  Either way libldap will try an open the connection so when fr_ldap_state_next
 *  returns we should have the file descriptor to pass back.
 *
 *  The complete order of operations is:
 *
 *  - Initialise the libldap handle with fr_ldap_connection_configure (calls ldap_init)
 *  - Initiate the connection with fr_ldap_state_next, which either binds or calls start_tls.
 *  - Either operation calls ldap_send_server_request.
 *    - Which calls ldap_new_connection.
 *    - Which calls ldap_int_open_connection.
 *    - Which calls ldap_connect_to_(host|path) and adds socket buffers, and possibly
 *      calls ldap_int_tls_start (for ldaps://).
 *    - When ldap_new_connection returns, because LDAP_OPT_CONNECT_ASYNC
 *      is set to LDAP_OPT_ON, lc->lconn_status is set to LDAP_CONNST_CONNECTING.
 *    - ldap_send_server_request checks for lconn_stats == LDAP_CONNST_CONNECTING,
 *      and calls ldap_int_poll, which checks the fd for error conditions
 *      and immediately returns due to the network timeout value.
 *    - If the socket is not yet connected:
 *      - As network timeout on the LDAP handle is 0, ld->ld_errno is set to
 *        LDAP_X_CONNECTING. ldap_send_server_request returns -1.
 *      - bind or start_tls errors with LDAP_X_CONNECTING without sending the request.
 *      - We install a write I/O handler, and wait to be called again, then we retry the
 *        operation.
 *    - else
 *      - the bind or start_tls operation succeeds, our ldap state machine advances,
 *        the connection callback is called and our socket state machine transitions to
 *        connected.
 *  - Continue running the state machine
 *
 * @param[out] h        Underlying file descriptor from libldap handle.
 * @param[in] conn      Being initialised.
 * @param[in] uctx      Our LDAP connection handle (a #fr_ldap_connection_t).
 * @return
 *      - FR_CONNECTION_STATE_CONNECTING on success.
 *      - FR_CONNECTION_STATE_FAILED on failure.
 */
static fr_connection_state_t _ldap_connection_init(void **h, fr_connection_t *conn, void *uctx)
{
        fr_ldap_config_t const  *config = uctx;
        fr_ldap_connection_t    *c;
        fr_ldap_state_t         state;
 
        c = fr_ldap_connection_alloc(conn);
        c->conn = conn;
        /*
         *      Initialise tree for outstanding queries handled by this connection
         */
        MEM(c->queries = fr_rb_inline_talloc_alloc(c, fr_ldap_query_t, node, fr_ldap_query_cmp, NULL));
        fr_dlist_init(&c->refs, fr_ldap_query_t, entry);
 
        /*
         *      Configure/allocate the libldap handle
         */
        if (fr_ldap_connection_configure(c, config) < 0) {
        error:
                talloc_free(c);
                return FR_CONNECTION_STATE_FAILED;
        }
 
        /* Don't block */
        if (ldap_set_option(c->handle, LDAP_OPT_CONNECT_ASYNC, LDAP_OPT_ON) != LDAP_OPT_SUCCESS) goto error;
        fr_ldap_connection_timeout_set(c, fr_time_delta_wrap(0));       /* Forces LDAP_X_CONNECTING */
 
        state = fr_ldap_state_next(c);
        if (state == FR_LDAP_STATE_ERROR) goto error;
 
        fr_connection_add_watch_pre(conn, FR_CONNECTION_STATE_CLOSED, _ldap_connection_close_watch, true, c);
 
        *h = c; /* Set the handle */
 
        return FR_CONNECTION_STATE_CONNECTING;
}
 
/** Alloc a self re-establishing connection to an LDAP server
 *
 * @param[in] ctx               to allocate any memory in, and to bind the lifetime of the connection to.
 * @param[in] el                to insert I/O and timer callbacks into.
 * @param[in] config            to use to bind the connection to an LDAP server.
 * @param[in] log_prefix        to prepend to connection state messages.
 */
fr_connection_t *fr_ldap_connection_state_alloc(TALLOC_CTX *ctx, fr_event_list_t *el,
                                                fr_ldap_config_t const *config, char const *log_prefix)
{
        fr_connection_t *conn;
 
        conn = fr_connection_alloc(ctx, el,
                                   &(fr_connection_funcs_t){
                                        .init = _ldap_connection_init,
                                        .close = _ldap_connection_close
                                   },
                                   &(fr_connection_conf_t){
                                        .connection_timeout = config->net_timeout,
                                        .reconnection_delay = config->reconnection_delay
                                   },
                                   log_prefix, config);
        if (!conn) {
                PERROR("Failed allocating state handler for new LDAP connection");
                return NULL;
        }
 
        return conn;
}
 
int fr_ldap_connection_timeout_set(fr_ldap_connection_t const *c, fr_time_delta_t timeout)
{
        int ldap_errno;
 
        /*
         *      A value of zero results in an handle configuration failure.
         *
         *      When most people specify zero they mean infinite.
         *
         *      libldap requires tv_sec to be -1 to mean that.
         */
        do_ldap_option(LDAP_OPT_NETWORK_TIMEOUT, "net_timeout",
                       (fr_time_delta_ispos(timeout) ?
                                &fr_time_delta_to_timeval(timeout) :
                                &(struct timeval) { .tv_sec = -1, .tv_usec = 0 }));
 
        return 0;
 
error:
        return -1;
}
 
int fr_ldap_connection_timeout_reset(fr_ldap_connection_t const *c)
{
        int ldap_errno;
 
        /*
         *      A value of zero results in an handle configuration failure.
         *
         *      When most people specify zero they mean infinite.
         *
         *      libldap requires tv_sec to be -1 to mean that.
         */
        do_ldap_option(LDAP_OPT_NETWORK_TIMEOUT, "net_timeout",
                       (fr_time_delta_ispos(c->config->net_timeout) ?
                                &fr_time_delta_to_timeval(c->config->net_timeout) :
                                &(struct timeval) { .tv_sec = -1, .tv_usec = 0 }));
 
        return 0;
 
error:
        return -1;
}
 
/** Callback for closing idle LDAP trunk
 *
 */
static void _ldap_trunk_idle_timeout(fr_event_list_t *el, UNUSED fr_time_t now, void *uctx)
{
        fr_ldap_thread_trunk_t  *ttrunk = talloc_get_type_abort(uctx, fr_ldap_thread_trunk_t);
 
        if (ttrunk->trunk->req_alloc == 0) {
                DEBUG2("Removing idle LDAP trunk to \"%s\"", ttrunk->uri);
                talloc_free(ttrunk->trunk);
                talloc_free(ttrunk);
        } else {
                /*
                 *      There are still pending queries - insert a new event
                 */
                (void) fr_event_timer_in(ttrunk, el, &ttrunk->ev, ttrunk->t->config->idle_timeout,
                                         _ldap_trunk_idle_timeout, ttrunk);
        }
}
 
/** Callback when an LDAP trunk request is cancelled
 *
 * Ensure the request is removed from the list of outstanding requests
 */
static void ldap_request_cancel(UNUSED fr_connection_t *conn, void *preq, UNUSED fr_trunk_cancel_reason_t reason,
                                UNUSED void *uctx) {
        fr_ldap_query_t *query = talloc_get_type_abort(preq, fr_ldap_query_t);
 
        if (query->ldap_conn) {
                fr_rb_remove(query->ldap_conn->queries, query);
                query->ldap_conn = NULL;
        }
}
 
/** Callback to cancel LDAP queries
 *
 * Inform the remote LDAP server that we no longer want responses to specific queries.
 *
 * @param[in] el        For timer management.
 * @param[in] tconn     The trunk connection handle
 * @param[in] conn      The specific connection queries will be cancelled on
 * @param[in] uctx      Context provided to fr_trunk_alloc
 */
static void ldap_request_cancel_mux(UNUSED fr_event_list_t *el, fr_trunk_connection_t *tconn,
                                    fr_connection_t *conn, UNUSED void *uctx)
{
        fr_trunk_request_t      *treq;
        fr_ldap_connection_t    *ldap_conn = talloc_get_type_abort(conn->h, fr_ldap_connection_t);
        fr_ldap_query_t         *query;
 
        while ((fr_trunk_connection_pop_cancellation(&treq, tconn)) == 0) {
                query = talloc_get_type_abort(treq->preq, fr_ldap_query_t);
                ldap_abandon_ext(ldap_conn->handle, query->msgid, NULL, NULL);
 
                fr_trunk_request_signal_cancel_complete(treq);
        }
}
 
/** Callback to tidy up when a trunk request fails
 *
 */
static void ldap_request_fail(request_t *request, void *preq, UNUSED void *rctx,
                              UNUSED fr_trunk_request_state_t state, UNUSED void *uctx)
{
        fr_ldap_query_t         *query = talloc_get_type_abort(preq, fr_ldap_query_t);
 
        /*
         *      Failed trunk requests get freed - so remove association in query.
         */
        query->treq = NULL;
        query->ret = LDAP_RESULT_ERROR;
 
        /*
         *      Ensure request is runnable.
         */
        if (request) unlang_interpret_mark_runnable(request);
}
 
/** I/O read function
 *
 * Underlying FD is now readable - call the trunk to read any pending requests.
 *
 * @param[in] el        The event list signalling.
 * @param[in] fd        that's now readable.
 * @param[in] flags     describing the read event.
 * @param[in] uctx      The trunk connection handle.
 */
static void ldap_conn_readable(UNUSED fr_event_list_t *el, UNUSED int fd, UNUSED int flags, void *uctx)
{
        fr_trunk_connection_t   *tconn = talloc_get_type_abort(uctx, fr_trunk_connection_t);
 
        fr_trunk_connection_signal_readable(tconn);
}
 
 
/** I/O write function
 *
 * Underlying FD is now writable - call the trunk to write any pending requests.
 *
 * @param[in] el        The event list signalling.
 * @param[in] fd        that's now writable.
 * @param[in] flags     describing the write event.
 * @param[in] uctx      The trunk connection handle
 */
static void ldap_conn_writable(UNUSED fr_event_list_t *el, UNUSED int fd, UNUSED int flags, void *uctx)
{
        fr_trunk_connection_t   *tconn = talloc_get_type_abort(uctx, fr_trunk_connection_t);
 
        fr_trunk_connection_signal_writable(tconn);
}
 
 
/** I/O error function
 *
 * The event loop signalled that a fatal error occurec on this connection.
 *
 * @param[in] el        The event list signalling.
 * @param[in] fd        that errored.
 * @param[in] flags     EL flags.
 * @param[in] fd_errno  The nature of the error.
 * @param[in] uctx      The trunk connection handle
 */
static void ldap_conn_error(UNUSED fr_event_list_t *el, UNUSED int fd, UNUSED int flags, int fd_errno, void *uctx)
{
        fr_trunk_connection_t   *tconn = talloc_get_type_abort(uctx, fr_trunk_connection_t);
 
        ERROR("%s - Connection failed: %s", tconn->conn->name, fr_syserror(fd_errno));
 
        fr_connection_signal_reconnect(tconn->conn, FR_CONNECTION_FAILED);
}
 
/** Setup callbacks requested by LDAP trunk connections
 *
 * @param[in] tconn     Trunk handle.
 * @param[in] conn      Individual connection callbacks are to be installed for.
 * @param[in] el        The event list to install events in.
 * @param[in] notify_on The types of event the trunk wants to be notified on.
 * @param[in] uctx      Context provided to fr_trunk_alloc.
 */
static void ldap_trunk_connection_notify(fr_trunk_connection_t *tconn, fr_connection_t *conn,
                                         fr_event_list_t *el,
                                         fr_trunk_connection_event_t notify_on, UNUSED void *uctx)
{
        fr_ldap_connection_t    *ldap_conn = talloc_get_type_abort(conn->h, fr_ldap_connection_t);
        fr_event_fd_cb_t        read_fn = NULL;
        fr_event_fd_cb_t        write_fn = NULL;
 
        switch (notify_on) {
        case FR_TRUNK_CONN_EVENT_NONE:
                fr_event_fd_delete(el, ldap_conn->fd, FR_EVENT_FILTER_IO);
                return;
 
        case FR_TRUNK_CONN_EVENT_READ:
                read_fn = ldap_conn_readable;
                break;
 
        case FR_TRUNK_CONN_EVENT_WRITE:
                write_fn = ldap_conn_writable;
                break;
 
        case FR_TRUNK_CONN_EVENT_BOTH:
                read_fn = ldap_conn_readable;
                write_fn = ldap_conn_writable;
                break;
        }
 
        if (fr_event_fd_insert(ldap_conn, NULL, el, ldap_conn->fd,
                               read_fn,
                               write_fn,
                               ldap_conn_error,
                               tconn) < 0) {
                PERROR("Failed inserting FD event");
                fr_trunk_connection_signal_reconnect(tconn, FR_CONNECTION_FAILED);
        }
}
 
/** Allocate an LDAP 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 fr_trunk_alloc.
 */
static fr_connection_t *ldap_trunk_connection_alloc(fr_trunk_connection_t *tconn, fr_event_list_t *el,
                                                    UNUSED fr_connection_conf_t const *conn_conf,
                                                    char const *log_prefix, void *uctx)
{
        fr_ldap_thread_trunk_t  *thread_trunk = talloc_get_type_abort(uctx, fr_ldap_thread_trunk_t);
 
        return fr_ldap_connection_state_alloc(tconn, el, &thread_trunk->config, log_prefix);
}
 
#define POPULATE_LDAP_CONTROLS(_dest, _src) do { \
        int i; \
        for (i = 0; (i < LDAP_MAX_CONTROLS) && (_src[i].control); i++) { \
                _dest[i] = _src[i].control; \
        } \
        _dest[i] = NULL; \
} while (0)
 
/** Take LDAP pending queries from the queue and send them.
 *
 * @param[in] el        Event list for timers.
 * @param[in] tconn     Trunk handle.
 * @param[in] conn      on which to send the queries
 * @param[in] uctx      User context passed to fr_trunk_alloc
 */
static void ldap_trunk_request_mux(UNUSED fr_event_list_t *el, fr_trunk_connection_t *tconn,
                                   fr_connection_t *conn, UNUSED void *uctx)
{
        fr_ldap_connection_t    *ldap_conn = talloc_get_type_abort(conn->h, fr_ldap_connection_t);
        fr_trunk_request_t      *treq;
 
        LDAPURLDesc             *referral_url = NULL;
 
        fr_ldap_query_t         *query = NULL;
        fr_ldap_rcode_t         status;
 
        while (fr_trunk_connection_pop_request(&treq, tconn) == 0) {
                LDAPControl     *our_serverctrls[LDAP_MAX_CONTROLS + 1];
                LDAPControl     *our_clientctrls[LDAP_MAX_CONTROLS + 1];
 
                if (!treq) break;
 
                query = talloc_get_type_abort(treq->preq, fr_ldap_query_t);
 
                switch (query->type) {
                case LDAP_REQUEST_SEARCH:
                        /*
                         *      This query is a LDAP search
                         */
                        if (query->referral) referral_url = query->referral->referral_url;
 
                        POPULATE_LDAP_CONTROLS(our_serverctrls, query->serverctrls);
                        POPULATE_LDAP_CONTROLS(our_clientctrls, query->clientctrls);
 
                        /*
                         *      If we are chasing a referral, referral_url will be populated and may
                         *      have a base dn or scope to override the original query
                         */
                        status = fr_ldap_search_async(&query->msgid, query->treq->request, ldap_conn,
                                                      (referral_url && referral_url->lud_dn) ?
                                                        referral_url->lud_dn : query->dn,
                                                      (referral_url && referral_url->lud_scope) ?
                                                        referral_url->lud_scope : query->search.scope,
                                                      query->search.filter, query->search.attrs,
                                                      our_serverctrls, our_clientctrls);
                        break;
 
                case LDAP_REQUEST_MODIFY:
                        /*
                         *      This query is an LDAP modification
                         */
                        POPULATE_LDAP_CONTROLS(our_serverctrls, query->serverctrls);
                        POPULATE_LDAP_CONTROLS(our_clientctrls, query->clientctrls);
 
                        status = fr_ldap_modify_async(&query->msgid, query->treq->request,
                                                      ldap_conn, query->dn, query->mods,
                                                      our_serverctrls, our_clientctrls);
                        break;
 
                case LDAP_REQUEST_EXTENDED:
                        /*
                         *      This query is an LDAP extended operation.
                         */
                        status = fr_ldap_extended_async(&query->msgid, query->treq->request, ldap_conn,
                                                        query->extended.reqoid, query->extended.reqdata);
                        break;
 
                default:
                        status = LDAP_PROC_ERROR;
                        ERROR("Invalid LDAP query for trunk connection");
                error:
                        fr_trunk_request_signal_fail(query->treq);
                        if (status == LDAP_PROC_BAD_CONN) fr_trunk_connection_signal_reconnect(tconn,
                                                                                               FR_CONNECTION_FAILED);
                        continue;
 
                }
 
                if (status != LDAP_PROC_SUCCESS) goto error;
 
                /*
                 *      If the query has previously been associated with a different
                 *      connection, remove that reference.  Typically when following references.
                 */
                if (query->ldap_conn) fr_dlist_remove(&query->ldap_conn->refs, query);
 
                /*
                 *      Record which connection was used for this query
                 *      - results processing often needs access to an LDAP handle
                 */
                query->ldap_conn = ldap_conn;
 
                /*
                 *      Add the query to the tree of pending queries for this trunk
                 */
                fr_rb_insert(query->ldap_conn->queries, query);
 
                fr_trunk_request_signal_sent(treq);
        }
 
}
 
/** Read LDAP responses
 *
 * Responses from the LDAP server will cause the fd to become readable and trigger this
 * callback.  Most LDAP search responses have multiple messages in their response - we
 * only gather those which are complete before either following a referral or passing
 * the head of the resulting chain of messages back.
 *
 * @param[in] el        To insert timers into.
 * @param[in] tconn     Trunk connection associated with these results.
 * @param[in] conn      Connection handle for these results.
 * @param[in] uctx      Thread specific trunk structure - contains tree of pending queries.
 */
static void ldap_trunk_request_demux(fr_event_list_t *el, fr_trunk_connection_t *tconn, fr_connection_t *conn, void *uctx)
{
        fr_ldap_connection_t    *ldap_conn = talloc_get_type_abort(conn->h, fr_ldap_connection_t);
        fr_ldap_thread_trunk_t  *ttrunk = talloc_get_type_abort(uctx, fr_ldap_thread_trunk_t);
 
        int                     ret = 0, msgtype;
        struct timeval          poll = { 0, 10 };
        LDAPMessage             *result = NULL;
        fr_ldap_rcode_t         rcode;
        fr_ldap_query_t         find = { .msgid = -1 }, *query = NULL;
        request_t               *request;
        bool                    really_no_result = false;
        fr_trunk_request_t      *treq;
 
        /*
         *  Reset the idle timeout event
         */
        (void) fr_event_timer_in(ttrunk, el, &ttrunk->ev,
                                 ttrunk->t->config->idle_timeout, _ldap_trunk_idle_timeout, ttrunk);
 
        do {
                /*
                 *      Look for any results for which we have the complete result message
                 *      ldap_result will return a pointer to a chain of messages.
                 *
                 *      The first time ldap_result is called when there's pending network
                 *      data, it may read the data, but not return any results.
                 *
                 *      In order to fix the spurious debugging messages and overhead,
                 *      if this is the first iteration through the loop and ldap_result
                 *      returns no result (0), we call it again.
                 */
                ret = ldap_result(ldap_conn->handle, LDAP_RES_ANY, LDAP_MSG_ALL, &poll, &result);
                switch (ret) {
                case 0:
                        if (really_no_result) return;
                        really_no_result = true;
                        continue;
 
                case -1:
                        rcode = fr_ldap_error_check(NULL, ldap_conn, NULL, NULL);
                        if (rcode == LDAP_PROC_BAD_CONN) {
                                ERROR("Bad LDAP connection");
                                fr_connection_signal_reconnect(tconn->conn, FR_CONNECTION_FAILED);
                        }
                        return;
 
                default:
                        /*
                         *      We only retry ldap_result the first time through the loop.
                         */
                        really_no_result = true;
                        break;
                }
 
                find.msgid = ldap_msgid(result);
                query = fr_rb_find(ldap_conn->queries, &find);
 
                if (!query) {
                        WARN("Ignoring msgid %i - doesn't match any outstanding queries (it may have been cancelled)",
                              find.msgid);
                        ldap_msgfree(result);
                        continue;
                }
 
                /*
                 *      Remove the query from the tree of outstanding queries
                 */
                fr_rb_remove(ldap_conn->queries, query);
 
                /*
                 *      Add the query to the list of queries referencing this connection.
                 *      Prevents the connection from being freed until the query has finished using it.
                 */
                fr_dlist_insert_tail(&ldap_conn->refs, query);
 
                /*
                 *      This really shouldn't happen - as we only retrieve complete sets of results -
                 *      but as the query data structure will last until its results are fully handled
                 *      better to have this safety check here.
                 */
                if (query->ret != LDAP_RESULT_PENDING) {
                        WARN("Received results for msgid %i which has already been handled - ignoring", find.msgid);
                        ldap_msgfree(result);
                        continue;
                }
 
                msgtype = ldap_msgtype(result);
 
                /*
                 *      Request to reference in debug output
                 */
                request = query->treq->request;
 
                ROPTIONAL(RDEBUG2, DEBUG2, "Got %s response for message %d",
                          ldap_msg_types[msgtype], query->msgid);
                rcode = fr_ldap_error_check(NULL, ldap_conn, result, query->dn);
 
                switch (rcode) {
                case LDAP_PROC_SUCCESS:
                        switch (query->type) {
                        case LDAP_REQUEST_SEARCH:
                                query->ret = (ldap_count_entries(ldap_conn->handle, result) == 0) ?
                                                LDAP_RESULT_NO_RESULT : LDAP_RESULT_SUCCESS;
                                break;
 
                        default:
                                query->ret = LDAP_RESULT_SUCCESS;
                                break;
                        }
                        break;
 
                case LDAP_PROC_REFERRAL:
                        if (!ttrunk->t->config->chase_referrals) {
                                ROPTIONAL(REDEBUG, ERROR,
                                          "LDAP referral received but 'chase_referrals' is set to 'no'");
                                query->ret = LDAP_RESULT_EXCESS_REFERRALS;
                                break;
                        }
 
                        if (query->referral_depth >= ttrunk->t->config->referral_depth) {
                                ROPTIONAL(REDEBUG, ERROR, "Maximum LDAP referral depth (%d) exceeded",
                                          ttrunk->t->config->referral_depth);
                                query->ret = LDAP_RESULT_EXCESS_REFERRALS;
                                break;
                        }
 
                        /*
                         *      If we've come here as the result of an existing referral
                         *      clear the previous list of URLs before getting the next list.
                         */
                        if (query->referral_urls) ldap_memvfree((void **)query->referral_urls);
 
                        ldap_get_option(ldap_conn->handle, LDAP_OPT_REFERRAL_URLS, &query->referral_urls);
                        if (!(query->referral_urls) || (!(query->referral_urls[0]))) {
                                ROPTIONAL(REDEBUG, ERROR, "LDAP referral missing referral URL");
                                query->ret = LDAP_RESULT_MISSING_REFERRAL;
                                break;
                        }
 
                        query->referral_depth ++;
 
                        if (fr_ldap_referral_follow(ttrunk->t, request, query) == 0) {
                        next_follow:
                                ldap_msgfree(result);
                                continue;
                        }
 
                        ROPTIONAL(REDEBUG, ERROR, "Unable to follow any LDAP referral URLs");
                        query->ret = LDAP_RESULT_REFERRAL_FAIL;
                        break;
 
                case LDAP_PROC_BAD_DN:
                        ROPTIONAL(RDEBUG2, DEBUG2, "DN %s does not exist", query->dn);
                        query->ret = LDAP_RESULT_BAD_DN;
                        break;
 
                default:
                        ROPTIONAL(RPERROR, PERROR, "LDAP server returned an error");
 
                        if (query->referral_depth > 0) {
                                /*
                                 *      We're processing a referral - see if there are any more to try
                                 */
                                fr_dlist_talloc_free_item(&query->referrals, query->referral);
                                query->referral = NULL;
 
                                if ((fr_dlist_num_elements(&query->referrals) > 0) &&
                                    (fr_ldap_referral_next(ttrunk->t, request, query) == 0)) goto next_follow;
                        }
 
                        query->ret = LDAP_RESULT_REFERRAL_FAIL;
                        break;
                }
 
                /*
                 *      Remove the timeout event
                 */
                if (query->ev) fr_event_timer_delete(&query->ev);
 
                query->result = result;
 
                /*
                 *      If we have a specific parser to handle the result, call it
                 */
                if (query->parser && (rcode == LDAP_PROC_SUCCESS)) query->parser(ldap_conn->handle, query,
                                                                                 result, query->treq->rctx);
 
                /*
                 *      Set the request as runnable
                 */
                if (request) unlang_interpret_mark_runnable(request);
 
                /*
                 *      If referral following failed, there is no active trunk request.
                 */
                if (!query->treq) continue;
 
                /*
                 *      If the query is parented off the treq then it will be freed when
                 *      the request is completed.  If it is parented by something else then it will not.
                 */
                treq = query->treq;
                query->treq = NULL;
                fr_trunk_request_signal_complete(treq);
        } while (1);
}
 
static int _thread_ldap_trunk_free(fr_ldap_thread_trunk_t *ttrunk)
{
        if (ttrunk->t && fr_rb_node_inline_in_tree(&ttrunk->node)) fr_rb_remove(ttrunk->t->trunks, ttrunk);
 
        return 0;
}
 
/** Find a thread specific LDAP connection for a specific URI / bind DN
 *
 * If no existing connection exists for that combination then create a new one
 *
 * @param[in] thread            to which the connection belongs
 * @param[in] uri               of the host to find / create a connection to
 * @param[in] bind_dn           to make the connection as
 * @param[in] bind_password     for making connection
 * @param[in] request           currently being processed (only for debug messages)
 * @param[in] config            LDAP config of the module requesting the connection.
 * @return
 *      - an existing or new connection matching the URI and bind DN
 *      - NULL on failure
 */
fr_ldap_thread_trunk_t *fr_thread_ldap_trunk_get(fr_ldap_thread_t *thread, char const *uri,
                                                 char const *bind_dn, char const *bind_password,
                                                 request_t *request, fr_ldap_config_t const *config)
{
        fr_ldap_thread_trunk_t  *found, find = {.uri = uri, .bind_dn = bind_dn};
 
        ROPTIONAL(RDEBUG2, DEBUG2, "Looking for LDAP connection to \"%s\" bound as \"%s\"", uri,
                 bind_dn ? bind_dn : "(anonymous)");
        found = fr_rb_find(thread->trunks, &find);
 
        if (found) return found;
 
        /*
         *      No existing connection matching the requirement - create a new one
         */
        ROPTIONAL(RDEBUG2, DEBUG2, "No existing connection found - creating new one");
        found = talloc_zero(thread, fr_ldap_thread_trunk_t);
        talloc_set_destructor(found, _thread_ldap_trunk_free);
 
        /*
         *      Build config for this connection - start with module settings and
         *      override server and bind details
         */
        memcpy(&found->config, config, sizeof(fr_ldap_config_t));
        found->config.server = talloc_strdup(found, uri);
        found->config.admin_identity = talloc_strdup(found, bind_dn);
        found->config.admin_password = talloc_strdup(found, bind_password);
 
        found->uri = found->config.server;
        found->bind_dn = found->config.admin_identity;
 
        found->trunk = fr_trunk_alloc(found, thread->el,
                                      &(fr_trunk_io_funcs_t){
                                              .connection_alloc = ldap_trunk_connection_alloc,
                                              .connection_notify = ldap_trunk_connection_notify,
                                              .request_mux = ldap_trunk_request_mux,
                                              .request_demux = ldap_trunk_request_demux,
                                              .request_cancel = ldap_request_cancel,
                                              .request_cancel_mux = ldap_request_cancel_mux,
                                              .request_fail = ldap_request_fail,
                                        },
                                      thread->trunk_conf,
                                      "rlm_ldap", found, false);
 
        if (!found->trunk) {
        error:
                ROPTIONAL(REDEBUG, ERROR, "Unable to create LDAP connection");
                talloc_free(found);
                return NULL;
        }
 
        found->t = thread;
 
        /*
         *  Insert event to close trunk if it becomes idle
         */
        if (!fr_cond_assert_msg(fr_event_timer_in(found, thread->el, &found->ev, thread->config->idle_timeout,
                                                  _ldap_trunk_idle_timeout, found) == 0, "cannot insert trunk idle event")) goto error;
 
        /*
         *      Attempt to discover what type directory we are talking to
         */
        if (fr_ldap_trunk_directory_alloc_async(found, found) < 0) goto error;
 
        fr_rb_insert(thread->trunks, found);
 
        return found;
}
 
/** Lookup the state of a thread specific LDAP connection trunk for a specific URI / bind DN
 *
 * @param[in] thread            to which the connection belongs
 * @param[in] uri               of the host to find / create a connection to
 * @param[in] bind_dn           to make the connection as
 * @return
 *      - State of a trunk matching the URI and bind DN
 *      - FR_TRUNK_STATE_MAX if no matching trunk
 */
fr_trunk_state_t fr_thread_ldap_trunk_state(fr_ldap_thread_t *thread, char const *uri, char const *bind_dn)
{
        fr_ldap_thread_trunk_t  *found, find = {.uri = uri, .bind_dn = bind_dn};
 
        found = fr_rb_find(thread->trunks, &find);
 
        return (found) ? found->trunk->state : FR_TRUNK_STATE_MAX;
}
 
/** Take pending LDAP bind auths from the queue and send them.
 *
 * @param[in] el        Event list for timers.
 * @param[in] tconn     Trunk handle.
 * @param[in] conn      on which to send the queries
 * @param[in] uctx      User context passed to fr_trunk_alloc
 */
static void ldap_trunk_bind_auth_mux(UNUSED fr_event_list_t *el, fr_trunk_connection_t *tconn,
                                   fr_connection_t *conn, void *uctx)
{
        fr_ldap_connection_t    *ldap_conn = talloc_get_type_abort(conn->h, fr_ldap_connection_t);
        fr_ldap_thread_trunk_t  *ttrunk = talloc_get_type_abort(uctx, fr_ldap_thread_trunk_t);
        fr_ldap_thread_t        *thread = ttrunk->t;
        fr_trunk_request_t      *treq;
 
        fr_ldap_bind_auth_ctx_t *bind = NULL;
        int                     ret = 0;
        struct berval           cred;
        request_t               *request;
 
        if (fr_trunk_connection_pop_request(&treq, tconn) != 0) return;
 
        /* Pacify clang scan */
        if (!treq) return;
 
        bind = talloc_get_type_abort(treq->preq, fr_ldap_bind_auth_ctx_t);
        request = bind->request;
 
        switch (bind->type) {
        case LDAP_BIND_SIMPLE:
        {
                fr_ldap_bind_ctx_t      *bind_ctx = bind->bind_ctx;
 
                RDEBUG2("Starting bind auth operation as %s", bind_ctx->bind_dn);
 
                if (bind_ctx->password) {
                        memcpy(&cred.bv_val, &bind_ctx->password, sizeof(cred.bv_val));
                        cred.bv_len = talloc_array_length(bind_ctx->password) - 1;
                } else {
                        cred.bv_val = NULL;
                        cred.bv_len = 0;
                }
 
                ret = ldap_sasl_bind(ldap_conn->handle, bind_ctx->bind_dn, LDAP_SASL_SIMPLE,
                                     &cred, NULL, NULL, &bind->msgid);
 
                switch (ret) {
                case LDAP_SUCCESS:
                        fr_rb_insert(thread->binds, bind);
                        RDEBUG3("Bind auth sent as LDAP msgid %d", bind->msgid);
                        break;
 
                default:
                        bind->ret = LDAP_PROC_ERROR;
                        unlang_interpret_mark_runnable(treq->request);
                        RERROR("Failed to send bind auth");
                        break;
                }
        }
                break;
 
#ifdef WITH_SASL
        case LDAP_BIND_SASL:
        {
                fr_ldap_sasl_ctx_t      *sasl_ctx = bind->sasl_ctx;
 
                RDEBUG2("%s SASL bind auth operation as %s", sasl_ctx->rmech ? "Continuing" : "Starting",
                        sasl_ctx->identity);
 
                ret = fr_ldap_sasl_bind_auth_send(sasl_ctx, &bind->msgid, ldap_conn);
 
                switch (ret) {
                case LDAP_SASL_BIND_IN_PROGRESS:
                        /*
                         *      Add the bind to the list of pending binds.
                         */
                        fr_rb_insert(thread->binds, bind);
                        RDEBUG3("SASL bind auth sent as LDAP msgid %d", bind->msgid);
                        break;
 
                case LDAP_SUCCESS:
                        bind->ret = LDAP_PROC_SUCCESS;
                        unlang_interpret_mark_runnable(treq->request);
                        break;
 
                default:
                        bind->ret = LDAP_PROC_ERROR;
                        unlang_interpret_mark_runnable(treq->request);
                        RERROR("Failed to send SASL bind auth");
                        break;
                }
        }
#endif
                break;
        }
        /*
         *      The request is marked as sent, to remove from the pending list.
         *      This is regardless of whether the sending was successful or not as
         *      the different states are handled by the resume function which then
         *      marks the request as complete triggering the tidy up.
         */
        fr_trunk_request_signal_sent(treq);
}
 
/** Read LDAP bind auth responses
 *
 * @param[in] el        To insert timers into.
 * @param[in] tconn     Trunk connection associated with these results.
 * @param[in] conn      Connection handle for these results.
 * @param[in] uctx      Thread specific trunk structure - contains tree of pending queries.
 */
static void ldap_trunk_bind_auth_demux(UNUSED fr_event_list_t *el, UNUSED fr_trunk_connection_t *tconn,
                                       fr_connection_t *conn, void *uctx)
{
        fr_ldap_connection_t    *ldap_conn = talloc_get_type_abort(conn->h, fr_ldap_connection_t);
        fr_ldap_thread_trunk_t  *ttrunk = talloc_get_type_abort(uctx, fr_ldap_thread_trunk_t);
        fr_ldap_thread_t        *thread = ttrunk->t;
        fr_ldap_bind_auth_ctx_t find = { .msgid = -1 }, *bind = NULL;
 
        int                     ret = 0;
        LDAPMessage             *result = NULL;
        request_t               *request;
        bool                    really_no_result = false;
 
        do {
                /*
                 *      The first time ldap_result is called when there's pending network
                 *      data, it may read the data, but actually return a timeout.
                 *
                 *      In order to fix the spurious debugging messages and overhead,
                 *      if this is the first iteration through the loop and fr_ldap_result
                 *      returns a timeout, we call it again.
                 */
                ret = fr_ldap_result(&result, NULL, ldap_conn, LDAP_RES_ANY, LDAP_MSG_ALL, NULL, fr_time_delta_wrap(10));
                if (ret == LDAP_PROC_TIMEOUT) {
                        if (really_no_result) return;
                        really_no_result = true;
                        continue;
                }
 
                if (!result) return;
 
                really_no_result = true;
                find.msgid = ldap_msgid(result);
                bind = fr_rb_find(thread->binds, &find);
 
                if (!bind) {
                        WARN("Ignoring bind result msgid %i - doesn't match any outstanding binds", find.msgid);
                        ldap_msgfree(result);
                        result = NULL;
                        continue;
                }
        } while (!bind);
 
        /*
         *      There will only ever be one bind in flight at a time on a given
         *      connection - so having got a result, no need to loop.
         */
 
        fr_rb_remove(thread->binds, bind);
        request = bind->request;
        bind->ret = ret;
 
        switch (ret) {
        /*
         *      Accept or reject will be SUCCESS, NOT_PERMITTED or REJECT
         */
        case LDAP_PROC_NOT_PERMITTED:
        case LDAP_PROC_REJECT:
        case LDAP_PROC_BAD_DN:
        case LDAP_PROC_NO_RESULT:
                break;
 
        case LDAP_PROC_SUCCESS:
                if (bind->type == LDAP_BIND_SIMPLE) break;
 
                /*
                 *      With SASL binds, we will be here after ldap_sasl_interactive_bind
                 *      returned LDAP_SASL_BIND_IN_PROGRESS.  That always requires a further
                 *      call of ldap_sasl_interactive_bind to get the final result.
                 */
                bind->ret = LDAP_PROC_CONTINUE;
                FALL_THROUGH;
 
        case LDAP_PROC_CONTINUE:
        {
                fr_ldap_sasl_ctx_t      *sasl_ctx = bind->sasl_ctx;
                struct berval           *srv_cred;
 
                /*
                 *      Free any previous result and track the new one.
                 */
                if (sasl_ctx->result) ldap_msgfree(sasl_ctx->result);
                sasl_ctx->result = result;
                result = NULL;
 
                ret = ldap_parse_sasl_bind_result(ldap_conn->handle, sasl_ctx->result, &srv_cred, 0);
                if (ret != LDAP_SUCCESS) {
                        RERROR("SASL decode failed (bind failed): %s", ldap_err2string(ret));
                        break;
                }
 
                if (srv_cred) {
                        RDEBUG3("SASL response  : %pV",
                                fr_box_strvalue_len(srv_cred->bv_val, srv_cred->bv_len));
                        ber_bvfree(srv_cred);
                }
 
                if (sasl_ctx->rmech) RDEBUG3("Continuing SASL mech %s...", sasl_ctx->rmech);
        }
                break;
 
        default:
                break;
        }
 
        ldap_msgfree(result);
        unlang_interpret_mark_runnable(request);
}
 
/** Callback to cancel LDAP bind auth
 *
 * Inform the remote LDAP server that we no longer want responses to specific bind.
 *
 * @param[in] el        For timer management.
 * @param[in] tconn     The trunk connection handle
 * @param[in] conn      The specific connection binds will be cancelled on
 * @param[in] uctx      Context provided to fr_trunk_alloc
 */
static void ldap_bind_auth_cancel_mux(UNUSED fr_event_list_t *el, fr_trunk_connection_t *tconn,
                                    fr_connection_t *conn, UNUSED void *uctx)
{
        fr_trunk_request_t      *treq;
        fr_ldap_connection_t    *ldap_conn = talloc_get_type_abort(conn->h, fr_ldap_connection_t);
        fr_ldap_bind_auth_ctx_t *bind;
 
        while ((fr_trunk_connection_pop_cancellation(&treq, tconn)) == 0) {
                bind = talloc_get_type_abort(treq->preq, fr_ldap_bind_auth_ctx_t);
#ifdef WITH_SASL
                if (bind->type == LDAP_BIND_SASL) {
                        /*
                         *      With SASL binds, abandoning the bind part way through
                         *      seems to leave the connection in an unpredictable state
                         *      so safer to restart.
                         */
                        fr_trunk_connection_signal_reconnect(tconn, FR_CONNECTION_FAILED);
                } else {
#endif
                        ldap_abandon_ext(ldap_conn->handle, bind->msgid, NULL, NULL);
#ifdef WITH_SASL
                }
#endif
                fr_trunk_request_signal_cancel_complete(treq);
        }
}
 
/** Callback to tidy up when a bind auth trunk request fails
 *
 */
static void ldap_trunk_bind_auth_fail(request_t *request, void *preq, UNUSED void *rctx,
                                UNUSED fr_trunk_request_state_t state, UNUSED void *uctx)
{
        fr_ldap_bind_auth_ctx_t *bind = talloc_get_type_abort(preq, fr_ldap_bind_auth_ctx_t);
 
        /*
         *      Failed trunk requests get freed - so remove association in bind structure,
         *      and change talloc parentage so resume function still has something to work with.
         */
        bind->treq = NULL;
        bind->ret = LDAP_PROC_ERROR;
        talloc_steal(NULL, bind);
 
        /*
         *      Ensure request is runnable.
         */
        if (request) unlang_interpret_mark_runnable(request);
}
 
/** Find the thread specific trunk to use for LDAP bind auths
 *
 * If there is no current trunk then a new one is created.
 *
 * @param[in] thread    to which the connection belongs
 * @return
 *      - an existing or new trunk.
 *      - NULL on failure
 */
fr_ldap_thread_trunk_t *fr_thread_ldap_bind_trunk_get(fr_ldap_thread_t *thread)
{
        fr_ldap_thread_trunk_t  *ttrunk;
 
        if (thread->bind_trunk) return (thread->bind_trunk);
 
        MEM(ttrunk = talloc_zero(thread, fr_ldap_thread_trunk_t));
        memcpy(&ttrunk->config, thread->config, sizeof(fr_ldap_config_t));
 
        ttrunk->uri = ttrunk->config.server;
        ttrunk->bind_dn = ttrunk->config.admin_identity;
 
        ttrunk->trunk = fr_trunk_alloc(ttrunk, thread->el,
                                       &(fr_trunk_io_funcs_t){
                                              .connection_alloc = ldap_trunk_connection_alloc,
                                              .connection_notify = ldap_trunk_connection_notify,
                                              .request_mux = ldap_trunk_bind_auth_mux,
                                              .request_demux = ldap_trunk_bind_auth_demux,
                                              .request_cancel_mux = ldap_bind_auth_cancel_mux,
                                              .request_fail = ldap_trunk_bind_auth_fail,
                                        },
                                       thread->bind_trunk_conf,
                                       "rlm_ldap bind auth", ttrunk, false);
 
        if (!ttrunk->trunk) {
                ERROR("Unable to create LDAP connection");
                talloc_free(ttrunk);
                return NULL;
        }
 
        ttrunk->t = thread;
        thread->bind_trunk = ttrunk;
 
        return ttrunk;
}