module_rlm.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: 1559ecfc620ccfa03ede71b420dbc26701a7f13d $
 *
 * @file src/lib/server/module_rlm.c
 * @brief Defines functions for rlm module (re-)initialisation.
 *
 * @copyright 2003,2006,2016 The FreeRADIUS server project
 * @copyright 2016,2024 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 * @copyright 2000 Alan DeKok (aland@freeradius.org)
 * @copyright 2000 Alan Curry (pacman@world.std.com)
 */
 
RCSID("$Id: 1559ecfc620ccfa03ede71b420dbc26701a7f13d $")
 
#include <freeradius-devel/server/cf_file.h>
#include <freeradius-devel/server/cf_util.h>
 
#include <freeradius-devel/server/global_lib.h>
#include <freeradius-devel/server/modpriv.h>
#include <freeradius-devel/server/module.h>
#include <freeradius-devel/server/module_rlm.h>
#include <freeradius-devel/server/pair.h>
#include <freeradius-devel/server/section.h>
#include <freeradius-devel/server/tmpl.h>
#include <freeradius-devel/server/virtual_servers.h>
 
#include <freeradius-devel/util/atexit.h>
#include <freeradius-devel/util/debug.h>
#include <freeradius-devel/util/dlist.h>
#include <freeradius-devel/util/rb.h>
#include <freeradius-devel/util/sbuff.h>
#include <freeradius-devel/util/strerror.h>
#include <freeradius-devel/util/talloc.h>
#include <freeradius-devel/util/token.h>
#include <freeradius-devel/util/value.h>
 
#include <freeradius-devel/unlang/compile.h>
 
#include <freeradius-devel/unlang/xlat_func.h>
#include <freeradius-devel/unlang/xlat_redundant.h>
 
#include <pthread.h>
 
/** Lookup virtual module by name
 */
static fr_rb_tree_t *module_rlm_virtual_name_tree;
 
typedef struct {
        fr_rb_node_t                    name_node;      //!< Entry in the name tree.
        char const                      *name;          //!< module name
        CONF_SECTION                    *cs;            //!< CONF_SECTION where it is defined
        bool                            all_same;
} module_rlm_virtual_t;
 
/** Compare virtual modules by name
 */
static int8_t module_rlm_virtual_name_cmp(void const *one, void const *two)
{
        module_rlm_virtual_t const *a = one;
        module_rlm_virtual_t const *b = two;
        int ret;
 
        ret = strcmp(a->name, b->name);
        return CMP(ret, 0);
}
 
/** Global module list for all backend modules
 *
 */
static module_list_t *rlm_modules_static;
 
/** Runtime instantiated list
 *
 */
static module_list_t *rlm_modules_dynamic;
 
/** Print information on all loaded modules
 *
 */
void module_rlm_list_debug(void)
{
        module_list_debug(rlm_modules_static);
}
 
/** Initialise a module specific exfile handle
 *
 * @see exfile_init
 *
 * @param[in] ctx               to bind the lifetime of the exfile handle to.
 * @param[in] module            section.
 * @param[in] max_entries       Max file descriptors to cache, and manage locks for.
 * @param[in] max_idle          Maximum time a file descriptor can be idle before it's closed.
 * @param[in] locking           Whether or not to lock the files.
 * @param[in] trigger_prefix    if NULL will be set automatically from the module CONF_SECTION.
 * @param[in] trigger_args      to make available in any triggers executed by the connection pool.
 * @return
 *      - New connection pool.
 *      - NULL on error.
 */
exfile_t *module_rlm_exfile_init(TALLOC_CTX *ctx,
                                 CONF_SECTION *module,
                                 uint32_t max_entries,
                                 fr_time_delta_t max_idle,
                                 bool locking,
                                 char const *trigger_prefix,
                                 fr_pair_list_t *trigger_args)
{
        char            trigger_prefix_buff[128];
        exfile_t        *handle;
 
        if (!trigger_prefix) {
                snprintf(trigger_prefix_buff, sizeof(trigger_prefix_buff), "modules.%s.file", cf_section_name1(module));
                trigger_prefix = trigger_prefix_buff;
        }
 
        handle = exfile_init(ctx, max_entries, max_idle, locking);
        if (!handle) return NULL;
 
        exfile_enable_triggers(handle, cf_section_find(module, "file", NULL), trigger_prefix, trigger_args);
 
        return handle;
}
 
/** Resolve polymorphic item's from a module's #CONF_SECTION to a subsection in another module
 *
 * This allows certain module sections to reference module sections in other instances
 * of the same module and share #CONF_DATA associated with them.
 *
 * @verbatim
   example {
        data {
                ...
        }
   }
 
   example inst {
        data = example
   }
 * @endverbatim
 *
 * @param[out] out where to write the pointer to a module's config section.  May be NULL on success,
 *      indicating the config item was not found within the module #CONF_SECTION
 *      or the chain of module references was followed and the module at the end of the chain
 *      did not a subsection.
 * @param[in] module #CONF_SECTION.
 * @param[in] name of the polymorphic sub-section.
 * @return
 *      - 0 on success with referenced section.
 *      - 1 on success with local section.
 *      - -1 on failure.
 */
int module_rlm_sibling_section_find(CONF_SECTION **out, CONF_SECTION *module, char const *name)
{
        CONF_PAIR               *cp;
        CONF_SECTION            *cs;
        CONF_DATA const         *cd;
 
 
        module_instance_t       *mi;
        char const              *inst_name;
 
#define FIND_SIBLING_CF_KEY "find_sibling"
 
        *out = NULL;
 
        /*
         *      Is a real section (not referencing sibling module).
         */
        cs = cf_section_find(module, name, NULL);
        if (cs) {
                *out = cs;
 
                return 0;
        }
 
        /*
         *      Item omitted completely from module config.
         */
        cp = cf_pair_find(module, name);
        if (!cp) return 0;
 
        if (cf_data_find(module, CONF_SECTION, FIND_SIBLING_CF_KEY)) {
                cf_log_err(cp, "Module reference loop found");
 
                return -1;
        }
        cd = cf_data_add(module, module, FIND_SIBLING_CF_KEY, false);
 
        /*
         *      Item found, resolve it to a module instance.
         *      This triggers module loading, so we don't have
         *      instantiation order issues.
         */
        inst_name = cf_pair_value(cp);
        mi = module_instance_by_name(rlm_modules_static, NULL, inst_name);
        if (!mi) {
                cf_log_err(cp, "Unknown module instance \"%s\"", inst_name);
 
                return -1;
        }
 
        if (mi->state != MODULE_INSTANCE_INSTANTIATED) {
                CONF_SECTION *parent = module;
 
                /*
                 *      Find the root of the config...
                 */
                do {
                        CONF_SECTION *tmp;
 
                        tmp = cf_item_to_section(cf_parent(parent));
                        if (!tmp) break;
 
                        parent = tmp;
                } while (true);
 
                if (unlikely(module_instantiate(module_instance_by_name(rlm_modules_static, NULL, inst_name)) < 0)) return -1;
        }
 
        /*
         *      Remove the config data we added for loop
         *      detection.
         */
        cf_data_remove_by_data(module, cd);
 
        /*
         *      Check the module instances are of the same type.
         */
        if (strcmp(cf_section_name1(mi->conf), cf_section_name1(module)) != 0) {
                cf_log_err(cp, "Referenced module is a rlm_%s instance, must be a rlm_%s instance",
                              cf_section_name1(mi->conf), cf_section_name1(module));
 
                return -1;
        }
 
        *out = cf_section_find(mi->conf, name, NULL);
 
        return 1;
}
 
xlat_t *module_rlm_xlat_register(TALLOC_CTX *ctx, module_inst_ctx_t const *mctx,
                                 char const *name, xlat_func_t func, fr_type_t return_type)
{
        module_instance_t       *mi = mctx->mi;
        module_rlm_instance_t   *mri = talloc_get_type_abort(mi->uctx, module_rlm_instance_t);
        module_rlm_xlat_t       *mrx;
        xlat_t                  *x;
        char                    inst_name[256];
 
        fr_assert_msg(name != mctx->mi->name, "`name` must not be the same as the module "
                      "instance name.  Pass a NULL `name` arg if this is required");
 
        if (!name) {
                name = mctx->mi->name;
        } else {
                if ((size_t)snprintf(inst_name, sizeof(inst_name), "%s.%s", mctx->mi->name, name) >= sizeof(inst_name)) {
                        ERROR("%s: Instance name too long", __FUNCTION__);
                        return NULL;
                }
                name = inst_name;
        }
 
        x = xlat_func_register(ctx, name, func, return_type);
        if (unlikely(x == NULL)) return NULL;
 
        xlat_mctx_set(x, mctx);
 
        MEM(mrx = talloc(mi, module_rlm_xlat_t));
        mrx->xlat = x;
        mrx->mi = mi;
 
        fr_dlist_insert_tail(&mri->xlats, mrx);
 
        return x;
}
 
/** Initialise a module specific connection pool
 *
 * @see fr_pool_init
 *
 * @param[in] module            section.
 * @param[in] opaque            data pointer to pass to callbacks.
 * @param[in] c                 Callback to create new connections.
 * @param[in] a                 Callback to check the status of connections.
 * @param[in] log_prefix        override, if NULL will be set automatically from the module CONF_SECTION.
 * @param[in] trigger_prefix    if NULL will be set automatically from the module CONF_SECTION.
 * @param[in] trigger_args      to make available in any triggers executed by the connection pool.
 * @return
 *      - New connection pool.
 *      - NULL on error.
 */
fr_pool_t *module_rlm_connection_pool_init(CONF_SECTION *module,
                                           void *opaque,
                                           fr_pool_connection_create_t c,
                                           fr_pool_connection_alive_t a,
                                           char const *log_prefix,
                                           char const *trigger_prefix,
                                           fr_pair_list_t *trigger_args)
{
        CONF_SECTION *cs, *mycs;
        char log_prefix_buff[128];
        char trigger_prefix_buff[128];
 
        fr_pool_t *pool;
        char const *cs_name1, *cs_name2;
 
        int ret;
 
#define parent_name(_x) cf_section_name(cf_item_to_section(cf_parent(_x)))
 
        cs_name1 = cf_section_name1(module);
        cs_name2 = cf_section_name2(module);
        if (!cs_name2) cs_name2 = cs_name1;
 
        if (!trigger_prefix) {
                snprintf(trigger_prefix_buff, sizeof(trigger_prefix_buff), "modules.%s.pool", cs_name1);
                trigger_prefix = trigger_prefix_buff;
        }
 
        if (!log_prefix) {
                snprintf(log_prefix_buff, sizeof(log_prefix_buff), "rlm_%s (%s)", cs_name1, cs_name2);
                log_prefix = log_prefix_buff;
        }
 
        /*
         *      Get sibling's pool config section
         */
        ret = module_rlm_sibling_section_find(&cs, module, "pool");
        switch (ret) {
        case -1:
                return NULL;
 
        case 1:
                DEBUG4("%s: Using pool section from \"%s\"", log_prefix, parent_name(cs));
                break;
 
        case 0:
                DEBUG4("%s: Using local pool section", log_prefix);
                break;
        }
 
        /*
         *      Get our pool config section
         */
        mycs = cf_section_find(module, "pool", NULL);
        if (!mycs) {
                DEBUG4("%s: Adding pool section to config item \"%s\" to store pool references", log_prefix,
                       cf_section_name(module));
 
                mycs = cf_section_alloc(module, module, "pool", NULL);
        }
 
        /*
         *      Sibling didn't have a pool config section
         *      Use our own local pool.
         */
        if (!cs) {
                DEBUG4("%s: \"%s.pool\" section not found, using \"%s.pool\"", log_prefix,
                       parent_name(cs), parent_name(mycs));
                cs = mycs;
        }
 
        /*
         *      If fr_pool_init has already been called
         *      for this config section, reuse the previous instance.
         *
         *      This allows modules to pass in the config sections
         *      they would like to use the connection pool from.
         */
        pool = cf_data_value(cf_data_find(cs, fr_pool_t, NULL));
        if (!pool) {
                DEBUG4("%s: No pool reference found for config item \"%s.pool\"", log_prefix, parent_name(cs));
                pool = fr_pool_init(cs, cs, opaque, c, a, log_prefix);
                if (!pool) return NULL;
 
                fr_pool_enable_triggers(pool, trigger_prefix, trigger_args);
 
                if (fr_pool_start(pool) < 0) {
                        ERROR("%s: Starting initial connections failed", log_prefix);
                        return NULL;
                }
 
                DEBUG4("%s: Adding pool reference %p to config item \"%s.pool\"", log_prefix, pool, parent_name(cs));
                cf_data_add(cs, pool, NULL, false);
                return pool;
        }
        fr_pool_ref(pool);
 
        DEBUG4("%s: Found pool reference %p in config item \"%s.pool\"", log_prefix, pool, parent_name(cs));
 
        /*
         *      We're reusing pool data add it to our local config
         *      section. This allows other modules to transitively
         *      reuse a pool through this module.
         */
        if (mycs != cs) {
                DEBUG4("%s: Copying pool reference %p from config item \"%s.pool\" to config item \"%s.pool\"",
                       log_prefix, pool, parent_name(cs), parent_name(mycs));
                cf_data_add(mycs, pool, NULL, false);
        }
 
        return pool;
}
 
/** Set the next section type if it's not already set
 *
 * @param[in] request           The current request.
 * @param[in] type_da           to use.  Usually attr_auth_type.
 * @param[in] enumv             Enumeration value of the specified type_da.
 */
bool module_rlm_section_type_set(request_t *request, fr_dict_attr_t const *type_da, fr_dict_enum_value_t const *enumv)
{
        fr_pair_t *vp;
 
        switch (pair_update_control(&vp, type_da)) {
        case 0:
                fr_value_box_copy(vp, &vp->data, enumv->value);
                vp->data.enumv = vp->da;        /* So we get the correct string alias */
                RDEBUG2("Setting &control.%pP", vp);
                return true;
 
        case 1:
                RDEBUG2("&control.%s already set.  Not setting to %s", vp->da->name, enumv->name);
                return false;
 
        default:
                return false;
        }
}
 
/** Iterate over an array of named module methods, looking for matches
 *
 * @param[in] mmg               A structure containing a terminated array of
 *                              module method bindings. pre-sorted using #section_name_cmp
 *                              with name2 sublists populated.
 * @param[in] section           name1 of the method being called can be one of the following:
 *                              - An itenfier.
 *                              - CF_IDENT_ANY if the method is a wildcard.
 *                              name2 of the method being called can be one of the following:
 *                              - An itenfier.
 *                              - NULL to match section names with only a name1.
 *                              - CF_IDENT_ANY if the method is a wildcard.
 * @return
 *      - The module_method_name_t on success.
 *      - NULL on not found.
 */
static CC_HINT(nonnull)
module_method_binding_t const *module_binding_find(module_method_group_t const *mmg, section_name_t const *section)
{
        module_method_group_t const *mmg_p = mmg;
        module_method_binding_t const *p;
 
        while (mmg_p) {
                /*
                 *      This could potentially be improved by using a binary search
                 *      but given the small number of items, reduced branches and
                 *      sequential access just scanning the list, it's probably not
                 *      worth it.
                 */
                for (p = mmg_p->bindings; p->section; p++) {
                        switch (section_name_match(p->section, section)) {
                        case 1:         /* match */
                                return p;
 
                        case -1:        /* name1 didn't match, skip to the end of the sub-list */
                                p = fr_dlist_tail(&p->same_name1);
                                break;
 
                        case 0:         /* name1 did match - see if we can find a matching name2 */
                        {
                                fr_dlist_head_t const *same_name1 = &p->same_name1;
 
                                while ((p = fr_dlist_next(same_name1, p))) {
                                        if (section_name2_match(p->section, section)) return p;
                                }
                                p = fr_dlist_tail(same_name1);
                        }
                                break;
                        }
#ifdef __clang_analyzer__
                        /* Will never be NULL, worse case, p doesn't change*/
                        if (!p) break;
#endif
                }
 
                /*
                 *      Failed to match, search the next deepest group in the chain.
                 */
                mmg_p = mmg_p->next;
        }
 
        return NULL;
}
 
/** Dump the available bindings for the module into the strerror stack
 *
 * @note Methods from _all_ linked module method groups will be pushed onto the error stack.
 *
 * @param[in] mmg       module method group to evaluate.
 */
static void module_rlm_methods_to_strerror(module_method_group_t const *mmg)
{
        module_method_group_t const     *mmg_p = mmg;
        module_method_binding_t const   *mmb_p;
        bool                            first = true;
 
        while (mmg_p) {
                mmb_p = mmg_p->bindings;
 
                if (!mmb_p || !mmb_p[0].section) goto next;
 
                if (first) {
                        fr_strerror_const_push("Available methods are:");
                        first = false;
                }
 
                for (; mmb_p->section; mmb_p++) {
                        char const *name1 = section_name_str(mmb_p->section->name1);
                        char const *name2 = section_name_str(mmb_p->section->name2);
 
                        fr_strerror_printf_push("  %s%s%s",
                                                name1, name2 ? "." : "", name2 ? name2 : "");
                }
        next:
                mmg_p = mmg_p->next;
        }
 
        if (first) {
                fr_strerror_const_push("No methods available");
        }
}
 
/** Find an existing module instance and verify it implements the specified method
 *
 * Extracts the method from the module name where the format is @verbatim <module>[.<method1>[.<method2>]] @endverbatim
 * and ensures the module implements the specified method.
 *
 * @param[in] ctx               to allocate the dynamic module key tmpl from.
 * @param[out] mmc_out          the result from resolving the module method,
 *                              plus the key tmpl for dynamic modules.
 *                              This is not allocated from the ctx to save the runtime
 *                              dereference.
 * @param[in] vs                Virtual server to search for alternative module names in.
 * @param[in] section           Section name containing the module call.
 * @param[in] name              The module method call i.e. module[<key>][.<method>]
 * @param[in] t_rules           for resolving the dynamic module key.
 * @return
 *      - The module instance on success.
 *      - NULL on not found
 *
 *  If the module exists but the method doesn't exist, then `method` is set to NULL.
 */
fr_slen_t module_rlm_by_name_and_method(TALLOC_CTX *ctx, module_method_call_t *mmc_out,
                                        virtual_server_t const *vs, section_name_t const *section, fr_sbuff_t *name,
                                        tmpl_rules_t const *t_rules)
{
        fr_sbuff_term_t const           *dyn_tt = &FR_SBUFF_TERMS(
                                                L(""),
                                                L("\t"),
                                                L("\n"),
                                                L(" "),
                                                L("[")
                                        );
 
        fr_sbuff_term_t const           *elem_tt = &FR_SBUFF_TERMS(
                                                L(""),
                                                L("\t"),
                                                L("\n"),
                                                L(" "),
                                                L(".")
                                        );
 
        fr_sbuff_t                      *elem1;
        module_method_call_t            *mmc;
        module_method_call_t            mmc_tmp;
        module_method_binding_t const   *mmb;
 
        fr_sbuff_marker_t               meth_start;
 
        fr_slen_t                       slen;
        fr_sbuff_t                      our_name = FR_SBUFF(name);
 
        mmc = mmc_out ? mmc_out : &mmc_tmp;
        if (mmc_out) memset(mmc_out, 0, sizeof(*mmc_out));
 
        /*
         *      Advance until the start of the dynamic selector
         *      (if it exists).
         */
        if (fr_sbuff_adv_until(&our_name, SIZE_MAX, dyn_tt, '\0') == 0) {
                fr_strerror_printf("Invalid module method name");
                return fr_sbuff_error(&our_name);
        }
 
        FR_SBUFF_TALLOC_THREAD_LOCAL(&elem1, MODULE_INSTANCE_LEN_MAX, (MODULE_INSTANCE_LEN_MAX + 1) * 10);
 
        /*
         *      If the method string contains a '['
         *
         *      Search for a dynamic module method, e.g. `elem1[<key>]`.
         */
        if (fr_sbuff_is_char(&our_name, '[')) {
                fr_sbuff_marker_t end, s_end;
                fr_sbuff_marker(&end, &our_name);
 
                slen = tmpl_afrom_substr(ctx, &mmc->key, &our_name, T_BARE_WORD, NULL, t_rules);
                if (slen < 0) {
                        fr_strerror_const_push("Invalid dynamic module selector expression");
                        talloc_free(mmc);
                        return slen;
                }
 
                if (!fr_sbuff_is_char(&our_name, ']')) {
                        fr_strerror_const_push("Missing terminating ']' for dynamic module selector");
                error:
                        talloc_free(mmc);
                        return fr_sbuff_error(&our_name);
                }
                fr_sbuff_marker(&s_end, &our_name);
 
                fr_sbuff_set_to_start(&our_name);
                slen = fr_sbuff_out_bstrncpy(elem1, &our_name, fr_sbuff_ahead(&end));
                if (slen < 0) {
                        fr_strerror_const("Module method string too long");
                        goto error;
                }
                mmc->mi = module_instance_by_name(rlm_modules_dynamic, NULL, elem1->start);
                if (!mmc->mi) {
                        fr_strerror_printf("No such dynamic module '%s'", elem1->start);
                        goto error;
                }
                mmc->rlm = module_rlm_from_module(mmc->mi->exported);
 
                fr_sbuff_set(&our_name, &s_end);
                fr_sbuff_advance(&our_name, 1); /* Skip the ']' */
        /*
         *      With elem1.elem2.elem3
         *
         *      Search for a static module matching one of the following:
         *
         *      - elem1.elem2.elem3
         *      - elem1.elem2
         *      - elem1
         */
        } else {
                char *p;
 
                fr_sbuff_set_to_start(&our_name);
 
                slen = fr_sbuff_out_bstrncpy_until(elem1, &our_name, SIZE_MAX, dyn_tt, NULL);
                if (slen == 0) {
                        fr_strerror_const("Invalid module name");
                        goto error;
                }
                if (slen < 0) {
                        fr_strerror_const("Module method string too long");
                        goto error;
                }
 
                /*
                 *      Now we have a mutable buffer, we can start chopping
                 *      it up to find the module.
                 */
                for (;;) {
                        mmc->mi = (module_instance_t *)module_rlm_static_by_name(NULL, elem1->start);
                        if (mmc->mi) {
                                mmc->rlm = module_rlm_from_module(mmc->mi->exported);
                                break;  /* Done */
                        }
 
                        p = strrchr(elem1->start, '.');
                        if (!p) break;  /* No more '.' */
                        *p = '\0';      /* Chop off the last '.' */
                }
 
                if (!mmc->mi) {
                        fr_strerror_printf("No such module '%pV'", fr_box_strvalue_len(our_name.start, slen));
                        return -1;
                }
 
                fr_sbuff_set_to_start(&our_name);
                fr_sbuff_advance(&our_name, strlen(elem1->start));      /* Advance past the module name */
                if (fr_sbuff_is_char(&our_name, '.')) {
                        fr_sbuff_advance(&our_name, 1);                 /* Static module method, search directly */
                } else {
                        fr_sbuff_marker(&meth_start, &our_name);        /* for the errors... */
                        goto by_section;                                /* Get the method dynamically from the section*/
                }
        }
 
        /*
         *      For both cases, the buffer should be pointing
         *      at the start of the method string.
         */
        fr_sbuff_marker(&meth_start, &our_name);
 
        /*
         *      If a module method was provided, search for it in the named
         *      methods provided by the module.
         *
         *      The method name should be either:
         *
         *      - name1
         *      - name1.name2
         */
        {
                section_name_t  method;
                fr_sbuff_t      *elem2;
 
                fr_sbuff_set_to_start(elem1);   /* May have used this already for module lookups */
 
                slen = fr_sbuff_out_bstrncpy_until(elem1, &our_name, SIZE_MAX, elem_tt, NULL);
                if (slen < 0) {
                        fr_strerror_const("Module method string too long");
                        return fr_sbuff_error(&our_name);
                }
                if (slen == 0) goto by_section; /* This works for both dynamic and static modules */
 
                FR_SBUFF_TALLOC_THREAD_LOCAL(&elem2, MODULE_INSTANCE_LEN_MAX, MODULE_INSTANCE_LEN_MAX);
 
                if (fr_sbuff_is_char(&our_name, '.')) {
                        fr_sbuff_advance(&our_name, 1);
                        if (fr_sbuff_out_bstrncpy_until(elem2, &our_name, SIZE_MAX,
                                                        elem_tt, NULL) == MODULE_INSTANCE_LEN_MAX) {
                                fr_strerror_const("Module method string too long");
                                goto error;
                        }
                }
 
                method = (section_name_t) {
                        .name1 = elem1->start,
                        .name2 = fr_sbuff_used(elem2) ? elem2->start : NULL
                };
 
                mmb = module_binding_find(&mmc->rlm->method_group, &method);
                if (!mmb) {
                        fr_strerror_printf("Module \"%s\" does not have method %s%s%s",
                                           mmc->mi->name,
                                           method.name1,
                                           method.name2 ? "." : "",
                                           method.name2 ? method.name2 : ""
                                           );
 
                        module_rlm_methods_to_strerror(&mmc->rlm->method_group);
                        return fr_sbuff_error(&meth_start);
                }
                mmc->mmb = *mmb;        /* For locality of reference and fewer derefs */
                if (mmc_out) section_name_dup(ctx, &mmc->asked, &method);
 
                return fr_sbuff_set(name, &our_name);
        }
 
by_section:
        /*
         *      First look for the section name in the module's
         *      bindings.  If that fails, look for the alt
         *      section names from the virtual server section.
         *
         *      If that fails, we're done.
         */
        mmb = module_binding_find(&mmc->rlm->method_group, section);
        if (!mmb) {
                section_name_t const **alt_p = virtual_server_section_methods(vs, section);
                if (alt_p) {
                        for (; *alt_p; alt_p++) {
                                mmb = module_binding_find(&mmc->rlm->method_group, *alt_p);
                                if (mmb) {
                                        if (mmc_out) section_name_dup(ctx, &mmc->asked, *alt_p);
                                        break;
                                }
                        }
                }
        } else {
                if (mmc_out) section_name_dup(ctx, &mmc->asked, section);
        }
        if (!mmb) {
                fr_strerror_printf("Module \"%s\" has no method for section %s %s { ... }, i.e. %s%s%s",
                                   mmc->mi->name,
                                   section->name1,
                                   section->name2 ? section->name2 : "",
                                   section->name1,
                                   section->name2 ? "." : "",
                                   section->name2 ? section->name2 : ""
                                   );
                module_rlm_methods_to_strerror(&mmc->rlm->method_group);
 
                return fr_sbuff_error(&meth_start);
        }
        mmc->mmb = *mmb;        /* For locality of reference and fewer derefs */
 
        return fr_sbuff_set(name, &our_name);
}
 
CONF_SECTION *module_rlm_virtual_by_name(char const *asked_name)
{
        module_rlm_virtual_t *inst;
 
        inst = fr_rb_find(module_rlm_virtual_name_tree,
                          &(module_rlm_virtual_t){
                                .name = asked_name,
                          });
        if (!inst) return NULL;
 
        return inst->cs;
}
 
module_instance_t *module_rlm_dynamic_by_name(module_instance_t const *parent, char const *asked_name)
{
        return module_instance_by_name(rlm_modules_dynamic, parent, asked_name);
}
 
module_instance_t *module_rlm_static_by_name(module_instance_t const *parent, char const *asked_name)
{
        return module_instance_by_name(rlm_modules_static, parent, asked_name);
}
 
/** Create a virtual module.
 *
 * @param[in] cs        that defines the virtual module.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int module_rlm_bootstrap_virtual(CONF_SECTION *cs)
{
        char const              *name;
        bool                    all_same;
        CONF_ITEM               *sub_ci = NULL;
        CONF_PAIR               *cp;
        module_instance_t       *mi;
        module_rlm_virtual_t    *inst;
 
        name = cf_section_name1(cs);
 
        /*
         *      Groups, etc. must have a name.
         */
        if ((strcmp(name, "group") == 0) ||
            (strcmp(name, "redundant") == 0) ||
            (strcmp(name, "redundant-load-balance") == 0) ||
            (strcmp(name, "load-balance") == 0)) {
                name = cf_section_name2(cs);
                if (!name) {
                        cf_log_err(cs, "Keyword module must have a second name");
                        return -1;
                }
 
                /*
                 *      name2 was already checked in modules_rlm_bootstrap()
                 */
                fr_assert(!unlang_compile_is_keyword(name));
        } else {
                cf_log_err(cs, "Module names cannot be unlang keywords '%s'", name);
                return -1;
        }
 
        /*
         *      Ensure that the module doesn't exist.
         */
        mi = module_instance_by_name(rlm_modules_static, NULL, name);
        if (mi) {
                ERROR("Duplicate module \"%s\" in file %s[%d] and file %s[%d]",
                      name,
                      cf_filename(cs),
                      cf_lineno(cs),
                      cf_filename(mi->conf),
                      cf_lineno(mi->conf));
                return -1;
        }
 
        /*
         *      Don't bother registering redundant xlats for a simple "group".
         */
        all_same = (strcmp(cf_section_name1(cs), "group") != 0);
 
        {
                module_t const          *last = NULL;
 
                /*
                *       Ensure that the modules we reference here exist.
                */
                while ((sub_ci = cf_item_next(cs, sub_ci))) {
                        if (cf_item_is_pair(sub_ci)) {
                                cp = cf_item_to_pair(sub_ci);
                                if (cf_pair_value(cp)) {
                                        cf_log_err(sub_ci, "Cannot set return codes in a %s block", cf_section_name1(cs));
                                        return -1;
                                }
 
                                mi = module_rlm_static_by_name(NULL, cf_pair_attr(cp));
                                if (!mi) {
                                        cf_log_perr(sub_ci, "Failed resolving module reference '%s' in %s block",
                                                    cf_pair_attr(cp), cf_section_name1(cs));
                                        return -1;
                                }
 
                                if (all_same) {
                                        if (!last) {
                                                last = mi->exported;
                                        } else if (last != mi->exported) {
                                                last = NULL;
                                                all_same = false;
                                        }
                                }
                        } else {
                                all_same = false;
                        }
 
                        /*
                        *       Don't check subsections for now.  That check
                        *       happens later in the unlang compiler.
                        */
                } /* loop over things in a virtual module section */
        }
 
        inst = talloc_zero(cs, module_rlm_virtual_t);
        if (!inst) return -1;
 
        inst->cs = cs;
        MEM(inst->name = talloc_strdup(inst, name));
        inst->all_same = all_same;
 
        if (!fr_cond_assert(fr_rb_insert(module_rlm_virtual_name_tree, inst))) {
                talloc_free(inst);
                return -1;
        }
 
        return 0;
}
 
/** Generic conf_parser_t func for loading drivers
 *
 */
int module_rlm_submodule_parse(TALLOC_CTX *ctx, void *out, void *parent,
                               CONF_ITEM *ci, conf_parser_t const *rule)
{
        conf_parser_t our_rule = *rule;
 
        our_rule.uctx = &rlm_modules_static;
 
        return module_submodule_parse(ctx, out, parent, ci, &our_rule);
}
 
/** Frees thread-specific data for all registered backend modules
 *
 */
void modules_rlm_thread_detach(void)
{
        modules_thread_detach(rlm_modules_static);
}
 
/** Allocates thread-specific data for all registered backend modules
 *
 * @param[in] ctx       To allocate any thread-specific data in.
 * @param[in] el        to register events.
 * @return
 *      - 0 if all modules were instantiated successfully.
 *      - -1 if a module failed instantiation.
 */
int modules_rlm_thread_instantiate(TALLOC_CTX *ctx, fr_event_list_t *el)
{
        return modules_thread_instantiate(ctx, rlm_modules_static, el);
}
 
/** Performs the instantiation phase for all backend modules
 *
 * @return
 *      - 0 if all modules were instantiated successfully.
 *      - -1 if a module failed instantiation.
 */
int modules_rlm_instantiate(void)
{
        return modules_instantiate(rlm_modules_static);
}
 
/** Compare the section names of two module_method_binding_t structures
 */
static int8_t binding_name_cmp(void const *one, void const *two)
{
        module_method_binding_t const *a = one;
        module_method_binding_t const *b = two;
 
        return section_name_cmp(a->section, b->section);
}
 
static int module_method_group_validate(module_method_group_t *group)
{
        module_method_binding_t *p, *srt_p;
        fr_dlist_head_t         bindings;
        bool                    in_order = true;
 
        /*
         *      Not all modules export module method bindings
         */
        if (!group || !group->bindings || group->validated) return 0;
 
        fr_dlist_init(&bindings, module_method_binding_t, entry);
 
        for (p = group->bindings; p->section; p++) {
                if (!fr_cond_assert_msg(p->section->name1,
                                        "First section identifier can't be NULL")) return -1;
                if (!fr_cond_assert_msg(p->section->name1 || p->section->name2,
                                        "Section identifiers can't both be null")) return -1;
 
                /*
                 *      All the bindings go in a list so we can sort them
                 *      and produce the list in the correct order.
                 */
                fr_dlist_insert_tail(&bindings, p);
        }
 
        fr_dlist_sort(&bindings, binding_name_cmp);
 
        /*
         *      Iterate over the sorted list of bindings,
         *      and the original list, to ensure they're
         *      in the correct order.
         */
        for (srt_p = fr_dlist_head(&bindings), p = group->bindings;
             srt_p;
             srt_p = fr_dlist_next(&bindings, srt_p), p++) {
                if (p != srt_p) {
                        in_order = false;
                        break;
                }
        }
 
        /*
         *      Rebuild the binding list in the correct order.
         */
        if (!in_order) {
                module_method_binding_t *ordered;
 
                MEM(ordered = talloc_array(NULL, module_method_binding_t, fr_dlist_num_elements(&bindings)));
                for (srt_p = fr_dlist_head(&bindings), p = ordered;
                     srt_p;
                     srt_p = fr_dlist_next(&bindings, srt_p), p++) {
                        *p = *srt_p;
                }
                memcpy(group->bindings, ordered, fr_dlist_num_elements(&bindings) * sizeof(*ordered));
                talloc_free(ordered);
        }
 
        /*
         *      Build the "skip" list of name1 entries
         */
        {
                module_method_binding_t *last_binding = NULL;
 
                for (p = group->bindings; p->section; p++) {
                        if (!last_binding ||
                                (
                                        (last_binding->section->name1 != p->section->name1) &&
                                        (
                                                (last_binding->section->name1 == CF_IDENT_ANY) ||
                                                (p->section->name1 == CF_IDENT_ANY) ||
                                                (strcmp(last_binding->section->name1, p->section->name1) != 0)
                                        )
                                )
                        ) {
                                fr_dlist_init(&p->same_name1, module_method_binding_t, entry);
                                last_binding = p;
                        }
                        fr_dlist_insert_tail(&last_binding->same_name1, p);
                }
        }
        group->validated = true;
 
        return module_method_group_validate(group->next);
}
 
static int module_method_validate(module_instance_t *mi)
{
        module_rlm_t *mrlm = module_rlm_from_module(mi->exported);
 
        return module_method_group_validate(&mrlm->method_group);
}
 
/** Allocate a rlm module instance
 *
 * These have extra space allocated to hold the dlist of associated xlats.
 *
 * @param[in] ml                Module list to allocate from.
 * @param[in] parent            Parent module instance.
 * @param[in] type              Type of module instance.
 * @param[in] mod_name          Name of the module.
 * @param[in] inst_name         Name of the instance.
 * @param[in] init_state        Initial state of the module instance.
 * @return
 *      - The allocated module instance on success.
 *      - NULL on failure.
 */
static inline CC_HINT(always_inline)
module_instance_t *module_rlm_instance_alloc(module_list_t *ml,
                                             module_instance_t const *parent,
                                             dl_module_type_t type, char const *mod_name, char const *inst_name,
                                             module_instance_state_t init_state)
{
        module_instance_t *mi;
        module_rlm_instance_t *mri;
 
        mi = module_instance_alloc(ml, parent, type, mod_name, inst_name, init_state);
        if (unlikely(mi == NULL)) return NULL;
 
        MEM(mri = talloc(mi, module_rlm_instance_t));
        module_instance_uctx_set(mi, mri);
 
        fr_dlist_talloc_init(&mri->xlats, module_rlm_xlat_t, entry);
 
        return mi;
}
 
static int module_conf_parse(module_list_t *ml, CONF_SECTION *mod_conf)
{
        char const              *name;
        char const              *inst_name;
        module_instance_t       *mi = NULL;
        CONF_SECTION            *actions;
 
        /*
         *      name2 can't be a keyword
         */
        name = cf_section_name2(mod_conf);
        if (name && unlang_compile_is_keyword(name)) {
        invalid_name:
                cf_log_err(mod_conf, "Module names cannot be unlang keywords '%s'", name);
                return -1;
        }
 
        name = cf_section_name1(mod_conf);
 
        /*
         *      For now, ignore name1 which is a keyword.
         */
        if (unlang_compile_is_keyword(name)) {
                if (!cf_section_name2(mod_conf)) {
                        cf_log_err(mod_conf, "Missing second name at '%s'", name);
                        return -1;
                }
                if (module_rlm_bootstrap_virtual(mod_conf) < 0) return -1;
                return 0;
        }
 
        /*
         *      Skip inline templates, and disallow "template { ... }"
         */
        if (strcmp(name, "template") == 0) {
                if (!cf_section_name2(mod_conf)) goto invalid_name;
                return 0;
        }
 
        if (module_instance_name_from_conf(&inst_name, mod_conf) < 0) goto invalid_name;
 
        mi = module_rlm_instance_alloc(ml, NULL, DL_MODULE_TYPE_MODULE, name, inst_name, 0);
        if (unlikely(mi == NULL)) {
                cf_log_perr(mod_conf, "Failed loading module");
                return -1;
        }
 
        /*
         *      First time we've loaded the dl module, so we need to
         *      check the module methods to make sure they're ordered
         *      correctly, and to add the "skip list" style name2
         *      entries.
         */
        if ((mi->module->refs == 1) && (module_method_validate(mi) < 0)) {
                talloc_free(mi);
                return -1;
        }
 
        if (module_instance_conf_parse(mi, mod_conf) < 0) {
                cf_log_perr(mod_conf, "Failed parsing module config");
                talloc_free(mi);
                return -1;
        }
 
        /*
         *      Compile the default "actions" subsection, which includes retries.
         */
        actions = cf_section_find(mod_conf, "actions", NULL);
        if (actions && unlang_compile_actions(&mi->actions, actions, (mi->exported->flags & MODULE_TYPE_RETRY) != 0)) {
                talloc_free(mi);
                return -1;
        }
 
        return 0;
}
 
/** Bootstrap modules and virtual modules
 *
 * Parse the module config sections, and load and call each module's init() function.
 *
 * @param[in] root of the server configuration.
 * @return
 *      - 0 if all modules were bootstrapped successfully.
 *      - -1 if a module/virtual module failed to bootstrap.
 */
int modules_rlm_bootstrap(CONF_SECTION *root)
{
        CONF_SECTION            *cs, *modules, *static_cs, *dynamic_cs;
        module_rlm_virtual_t    *vm;
        fr_rb_iter_inorder_t    iter;
 
        /*
         *      Ensure any libraries the modules depend on are instantiated
         */
        global_lib_instantiate();
 
        /*
         *      Remember where the modules were stored.
         */
        modules = cf_section_find(root, "modules", NULL);
        if (!modules) {
                WARN("Cannot find a \"modules\" section in the configuration file!");
                return 0;
        }
 
        static_cs = cf_section_find(modules, "static", NULL);
        if (!static_cs) {
                static_cs = cf_section_alloc(modules, NULL, "static", NULL);
                cf_section_foreach(modules, mod_cs) {
                        CONF_ITEM *prev;
 
                        /*
                         *      Skip over the dynamic section
                         */
                        if ((strcmp(cf_section_name1(mod_cs), "dynamic") == 0) &&
                            cf_section_name2(mod_cs) == NULL) continue;
 
                        /*
                         *      Move all modules which are not in
                         *      the dynamic section into the static
                         *      section for backwards compatibility.
                         */
                        prev = cf_item_remove(modules, mod_cs);
                        cf_item_add(static_cs, mod_cs);
 
                        /*
                         *      Find the previous item that's a section
                         */
                        while (prev && !cf_item_is_section(prev)) prev = cf_item_prev(modules, prev);
 
                        /*
                         *      Resume iterating from that item
                         */
                        mod_cs = cf_item_to_section(prev);
                }
                cf_item_add(modules, static_cs);
        }
        DEBUG2("#### Bootstrapping static modules ####");
        cf_log_debug(modules, " modules {");
        cf_log_debug(modules, "    static {");
        cf_section_foreach(static_cs, mod_conf) {
                if (module_conf_parse(rlm_modules_static, mod_conf) < 0) return -1;
        }
        cf_log_debug(modules, "    } # static");
 
        /*
         *      Now we have a module tree, run bootstrap on all the modules.
         *      This will bootstrap modules and then submodules.
         */
        if (unlikely(modules_bootstrap(rlm_modules_static) < 0)) return -1;
 
        if (fr_command_register_hook(NULL, NULL, static_cs, module_cmd_list_table) < 0) {
                PERROR("Failed registering radmin commands for modules");
                return -1;
        }
 
        /*
         *      Build the configuration and parse dynamic modules
         */
        dynamic_cs = cf_section_find(modules, "dynamic", NULL);
        if (dynamic_cs) {
                DEBUG2("#### Bootstrapping dynamic modules ####");
                /*
                *       Parse and then instantiate any dynamic modules configure
                */
                cf_log_debug(modules, "    dynamic {");
                cf_section_foreach(dynamic_cs, mod_conf) {
                        if (unlikely(module_conf_parse(rlm_modules_dynamic, mod_conf) < 0)) return -1;
                }
                cf_log_debug(modules, "    } # dynamic");
                if (unlikely(modules_bootstrap(rlm_modules_dynamic) < 0)) return -1;
                cf_log_debug(modules, " } # modules");
        }
 
        /*
         *      Check for duplicate policies.  They're treated as
         *      modules, so we might as well check them here.
         */
        cs = cf_section_find(root, "policy", NULL);
        if (cs) {
                cf_section_foreach(cs, policy_cs) {
                        CONF_SECTION    *problemcs;
                        char const      *name1 = cf_section_name1(policy_cs);
 
                        if (unlang_compile_is_keyword(name1)) {
                                cf_log_err(policy_cs, "Policy name '%s' cannot be an unlang keyword", name1);
                                return -1;
                        }
 
                        if (cf_section_name2(policy_cs)) {
                                cf_log_err(policy_cs, "Policies cannot have two names");
                                return -1;
                        }
 
                        problemcs = cf_section_find_next(cs, policy_cs, name1, CF_IDENT_ANY);
                        if (!problemcs) continue;
 
                        cf_log_err(problemcs, "Duplicate policy '%s' is forbidden.",
                                   cf_section_name1(policy_cs));
                        return -1;
                }
        }
 
        /*
         *      Now that all of the xlat things have been registered,
         *      register our redundant xlats.  But only when all of
         *      the items in such a section are the same.
         */
        for (vm = fr_rb_iter_init_inorder(&iter, module_rlm_virtual_name_tree);
             vm;
             vm = fr_rb_iter_next_inorder(&iter)) {
                if (!vm->all_same) continue;
 
                if (xlat_register_redundant(vm->cs) < 0) return -1;
        }
 
        return 0;
}
 
/** Cleanup all global structures
 *
 * Automatically called on exit.
 */
int modules_rlm_free(void)
{
        if (talloc_free(rlm_modules_static) < 0) return -1;
        rlm_modules_static = NULL;
        if (talloc_free(module_rlm_virtual_name_tree) < 0) return -1;
        module_rlm_virtual_name_tree = NULL;
 
        return 0;
}
 
static int _modules_rlm_free_atexit(UNUSED void *uctx)
{
        return modules_rlm_free();
}
 
/** Initialise the module list structure
 *
 */
int modules_rlm_init(void)
{
        MEM(rlm_modules_static = module_list_alloc(NULL, &module_list_type_global, "rlm", true));
        MEM(rlm_modules_dynamic = module_list_alloc(NULL, &module_list_type_thread_local, "rlm", true));
        module_list_mask_set(rlm_modules_dynamic, MODULE_INSTANCE_INSTANTIATED);        /* Ensure we never instantiate dynamic modules */
 
        MEM(module_rlm_virtual_name_tree = fr_rb_inline_alloc(NULL, module_rlm_virtual_t, name_node,
                                                              module_rlm_virtual_name_cmp, NULL));
        fr_atexit_global(_modules_rlm_free_atexit, NULL);
 
        return 0;
}