proto_ldap_sync.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: dfe9ae5938e3ec75f89dc1e4ebe56e4335cb89dc $
 * @file proto_ldap_sync.c
 * @brief LDAP sync protocol handler.
 *
 * @copyright 2022 Network RADIUS SAS (legal@networkradius.com)
 */
#define LOG_PREFIX "proto_ldap_sync"
 
#include <freeradius-devel/internal/internal.h>
#include <freeradius-devel/io/listen.h>
#include <freeradius-devel/server/module.h>
 
#include "proto_ldap_sync.h"
 
#include <fcntl.h>
 
static fr_internal_encode_ctx_t encode_ctx = { .allow_name_only = true };
 
extern fr_app_t proto_ldap_sync;
 
static conf_parser_t const ldap_sync_search_config[] = {
        { FR_CONF_OFFSET("base_dn", sync_config_t, base_dn), .dflt = "", .quote = T_SINGLE_QUOTED_STRING },
 
        { FR_CONF_OFFSET("filter", sync_config_t, filter) },
 
        { FR_CONF_OFFSET("scope", sync_config_t, scope_str), .dflt = "sub" },
        /* For persistent search directories, setting this to "no" will load the whole directory. */
        { FR_CONF_OFFSET("changes_only", sync_config_t, changes_only), .dflt = "yes" },
 
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t const proto_ldap_sync_config[] = {
        { FR_CONF_OFFSET_TYPE_FLAGS("transport", FR_TYPE_VOID, 0, proto_ldap_sync_t, io_submodule),
          .func = virtual_server_listen_transport_parse },
 
        { FR_CONF_OFFSET("max_packet_size", proto_ldap_sync_t, max_packet_size) },
        { FR_CONF_OFFSET("num_messages", proto_ldap_sync_t, num_messages) },
        { FR_CONF_OFFSET("cookie_interval", proto_ldap_sync_t, cookie_interval), .dflt = "10" },
        { FR_CONF_OFFSET("cookie_changes", proto_ldap_sync_t, cookie_changes), .dflt = "100" },
        { FR_CONF_OFFSET("retry_interval", proto_ldap_sync_t, retry_interval), .dflt = "1" },
 
        /*
         *      Areas of the DIT to listen on
         */
        { FR_CONF_SUBSECTION_ALLOC("sync", 0, CONF_FLAG_SUBSECTION | CONF_FLAG_MULTI | CONF_FLAG_REQUIRED, proto_ldap_sync_t, sync_config, ldap_sync_search_config) },
 
        CONF_PARSER_TERMINATOR
};
 
static fr_dict_t const *dict_ldap_sync;
 
extern fr_dict_autoload_t proto_ldap_sync_dict[];
fr_dict_autoload_t proto_ldap_sync_dict[] = {
        { .out = &dict_ldap_sync, .proto = "ldap" },
        { NULL }
};
 
static fr_dict_attr_t const *attr_ldap_sync_packet_id;
static fr_dict_attr_t const *attr_ldap_sync;
static fr_dict_attr_t const *attr_ldap_sync_cookie;
static fr_dict_attr_t const *attr_ldap_sync_dn;
static fr_dict_attr_t const *attr_ldap_sync_scope;
static fr_dict_attr_t const *attr_ldap_sync_filter;
static fr_dict_attr_t const *attr_packet_type;
 
extern fr_dict_attr_autoload_t proto_ldap_sync_dict_attr[];
fr_dict_attr_autoload_t proto_ldap_sync_dict_attr[] = {
        { .out = &attr_ldap_sync_packet_id, .name = "Sync-Packet-ID", .type = FR_TYPE_UINT32, .dict = &dict_ldap_sync },
        { .out = &attr_ldap_sync, .name = "LDAP-Sync", .type = FR_TYPE_TLV, .dict = &dict_ldap_sync },
        { .out = &attr_ldap_sync_cookie, .name = "LDAP-Sync.Cookie", .type = FR_TYPE_OCTETS, .dict = &dict_ldap_sync },
        { .out = &attr_ldap_sync_dn, .name = "LDAP-Sync.DN", .type = FR_TYPE_STRING, .dict = &dict_ldap_sync },
        { .out = &attr_ldap_sync_scope, .name = "LDAP-Sync.Scope", .type = FR_TYPE_UINT32, .dict = &dict_ldap_sync },
        { .out = &attr_ldap_sync_filter, .name = "LDAP-Sync.Filter", .type = FR_TYPE_STRING, .dict = &dict_ldap_sync },
        { .out = &attr_packet_type, .name = "Packet-Type", .type = FR_TYPE_UINT32, .dict = &dict_ldap_sync },
        { NULL }
};
 
/** Check if an attribute is in the config list and add if not present
 *
 * @param[in,out] config        to check for attribute.
 * @param[in] attr              to look for.
 * @return
 *      - 1 if attr is added
 *      - 0 if attr was already present
 */
int ldap_sync_conf_attr_add(sync_config_t *config, char const * attr)
{
        char    **tmp;
        size_t  len;
 
        if (fr_ldap_attrs_check(config->attrs, attr)) return 0;
 
        len = talloc_array_length(config->attrs);
 
        config->attrs[len - 1] = talloc_strdup(config, attr);
        tmp = (char **)talloc_array_null_terminate(UNCONST(void **, config->attrs));
        memcpy(&config->attrs, &tmp, sizeof(config->attrs));
 
        return 1;
}
 
/** Decode an internal LDAP sync packet
 *
 */
static int mod_decode(UNUSED void const *instance, request_t *request, uint8_t *const data, size_t data_len)
{
        fr_dbuff_t                      dbuff;
        ssize_t                         ret;
        fr_pair_t                       *vp = NULL;
 
        request->dict = dict_ldap_sync;
 
        fr_dbuff_init(&dbuff, data, data_len);
 
        /*
         *      Extract attributes from the passed data
         */
        ret = fr_internal_decode_list_dbuff(request->pair_list.request, &request->request_pairs,
                                           fr_dict_root(request->dict), &dbuff, NULL);
        if (ret < 0) return -1;
 
        vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_packet_type);
        fr_assert(vp);
        request->packet->code = vp->vp_uint32;
 
        vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_ldap_sync_packet_id);
        fr_assert(vp);
        request->packet->id = vp->vp_uint32;
        request->reply->id = vp->vp_uint32;
 
        return 0;
}
 
/** Encode responses to processing LDAP sync sections
 *
 */
static ssize_t mod_encode(UNUSED void const *instance, request_t *request, uint8_t *buffer, size_t buffer_len)
{
        fr_dbuff_t      dbuff;
        fr_pair_t       *sync_vp = NULL, *vp = NULL;
        fr_pair_list_t  pairs;
        TALLOC_CTX      *local = NULL;
 
        fr_dbuff_init(&dbuff, buffer, buffer_len);
        local = talloc_new(NULL);
        fr_pair_list_init(&pairs);
 
        fr_pair_list_append_by_da(local, vp, &pairs, attr_packet_type, request->reply->code, false);
        if (!vp) {
        error:
                talloc_free(local);
                return -1;
        }
        fr_pair_list_append_by_da(local, vp, &pairs, attr_ldap_sync_packet_id, (uint32_t)request->reply->id, false);
        if (!vp) goto error;
 
        /*
         *      Only Cookie Load Response has extra data sent - the cookie (if defined)
         */
        if (request->reply->code != FR_LDAP_SYNC_CODE_COOKIE_LOAD_RESPONSE) goto send;
 
        sync_vp = fr_pair_find_by_da(&request->reply_pairs, NULL, attr_ldap_sync);
        if (!sync_vp) goto send;
        vp = fr_pair_find_by_da(&sync_vp->vp_group, NULL, attr_ldap_sync_cookie);
        if ((vp) && (vp->data.vb_length > 0)) {
                fr_pair_remove(&request->reply_pairs, sync_vp);
                fr_pair_steal_append(local, &pairs, sync_vp);
        }
 
send:
        if (fr_internal_encode_list(&dbuff, &pairs, &encode_ctx) < 0) goto error;
        talloc_free(local);
 
        return fr_dbuff_used(&dbuff);
}
 
static int mod_open(void *instance, fr_schedule_t *sc, UNUSED CONF_SECTION *conf)
{
        proto_ldap_sync_t       *inst = talloc_get_type_abort(instance, proto_ldap_sync_t);
        fr_listen_t             *li;
 
        /*
         *      Build the #fr_listen_t.
         */
        MEM(li = talloc_zero(inst, fr_listen_t));
        talloc_set_destructor(li, fr_io_listen_free);
 
        li->app_io = inst->app_io;
        li->thread_instance = talloc_zero_array(NULL, uint8_t, li->app_io->common.thread_inst_size);
        talloc_set_name(li->thread_instance, "proto_%s_thread_t", inst->app_io->common.name);
        li->app_io_instance = inst->app_io_instance;
        li->name = "ldap_sync main listener";
 
        li->app = &proto_ldap_sync;
        li->app_instance = instance;
        li->server_cs = inst->server_cs;
        li->non_socket_listener = true;
 
        /*
         *      Set configurable parameters for message ring buffer.
         */
        li->default_message_size = inst->max_packet_size;
        li->num_messages = inst->num_messages;
 
        if (!fr_schedule_listen_add(sc, li)) {
                talloc_free(li);
                return -1;
        }
 
        inst->listen = li;
        inst->sc = sc;
 
        return 0;
}
 
static int mod_instantiate(module_inst_ctx_t const *mctx)
{
        proto_ldap_sync_t       *inst = talloc_get_type_abort(mctx->mi->data, proto_ldap_sync_t);
        CONF_SECTION            *conf = mctx->mi->conf;
        CONF_SECTION            *sync_cs;
        sync_config_t           *sync_conf;
        size_t                  i;
        fr_pair_t               *vp;
        CONF_SECTION            *map_cs;
        map_t                   *map;
        tmpl_rules_t            parse_rules = {
                /* Strict rules for the update map as it's processed with limited functionality */
                .attr = {
                        .dict_def = dict_ldap_sync,
                        .list_def = request_attr_request,
                        .allow_foreign = false,
                        .allow_unknown = false,
                        .allow_unresolved = false,
                        .list_presence = TMPL_ATTR_LIST_FORBID,
                }
        };
 
        inst->server_cs = cf_item_to_section(cf_parent(conf));
        inst->cs = conf;
        inst->self = &proto_ldap_sync;
 
        if (!inst->io_submodule) {
                cf_log_err(conf, "Virtual server for LDAP sync requires a 'transport' configuration");
                return -1;
        }
 
        /*
         *      Bootstrap the I/O module
         */
        inst->app_io = (fr_app_io_t const *) inst->io_submodule->exported;
        inst->app_io_instance = inst->io_submodule->data;
        inst->app_io_conf = inst->io_submodule->conf;
 
        /*
         *      These configuration items are not printed by default,
         *      because normal people shouldn't be touching them.
         */
        if (!inst->max_packet_size) inst->max_packet_size = inst->app_io->default_message_size;
        if (!inst->num_messages) inst->num_messages = 2;
 
        FR_INTEGER_BOUND_CHECK("num_messages", inst->num_messages, >=, 2);
        FR_INTEGER_BOUND_CHECK("num_messages", inst->num_messages, <=, 65535);
 
        FR_INTEGER_BOUND_CHECK("max_packet_size", inst->max_packet_size, >=, 1024);
        FR_INTEGER_BOUND_CHECK("max_packet_size", inst->max_packet_size, <=, 65536);
 
        if (!inst->priority) inst->priority = PRIORITY_NORMAL;
 
        /*
         *      Parse each of the sync sections
         */
        for (sync_cs = cf_section_find(conf, "sync", NULL), i = 0;
             sync_cs;
             sync_cs = cf_section_find_next(conf, sync_cs, "sync", NULL), i++) {
                sync_conf = inst->sync_config[i];
                sync_conf->cs = sync_cs;
 
                /*
                 *      Convert scope string to enumerated constant
                 */
                sync_conf->scope = fr_table_value_by_str(fr_ldap_scope, sync_conf->scope_str, -1);
                if (sync_conf->scope < 0) {
                        cf_log_err(conf, "Invalid 'search.scope' value \"%s\", expected 'sub', 'one', 'base' or 'children'",
                                   sync_conf->scope_str);
                        return -1;
                }
 
                map_cs = cf_section_find(sync_cs, "update", NULL);
                map_list_init(&sync_conf->entry_map);
                if (map_cs && map_afrom_cs(inst, &sync_conf->entry_map, map_cs,
                                           &parse_rules, &parse_rules, fr_ldap_map_verify, NULL,
                                           LDAP_MAX_ATTRMAP) < 0) {
                        return -1;
                }
 
                /*
                 *      Initialise a NULL terminated list of attributes
                 */
                sync_conf->attrs = talloc_array(sync_conf, char const *, 1);
                sync_conf->attrs[0] = NULL;
 
                if (map_list_empty(&sync_conf->entry_map)) {
                        cf_log_warn(conf, "LDAP sync specified without update map");
                        continue;
                }
 
                /*
                 *      Build the required list of attributes from the update map,
                 *      checking validity as we go.
                 */
                map = NULL;
                while ((map = map_list_next(&sync_conf->entry_map, map))) {
                        if (fr_type_is_structural(tmpl_attr_tail_da(map->lhs)->type)) {
                                cf_log_err(map->ci, "Structural attribute \"%s\" invalid for LDAP sync update",
                                            tmpl_attr_tail_da(map->lhs)->name);
                                return -1;
                        }
 
                        switch(map->op) {
                        case T_OP_EQ:
                        case T_OP_ADD_EQ:
                                break;
 
                        default:
                                cf_log_err(map->ci, "Operator \"%s\" invalid for LDAP sync update",
                                            fr_table_str_by_value(fr_tokens_table, map->op, "<INVALID>"));
                                return -1;
                        }
 
                        DEBUG3("Adding %s to attribute list", map->rhs->name);
                        ldap_sync_conf_attr_add(sync_conf, map->rhs->name);
                }
 
                /*
                 *      Build the list of pairs representing the sync config
                 */
                fr_pair_list_init(&sync_conf->sync_pairs);
 
                fr_pair_list_append_by_da_parent_len(sync_conf, vp, &sync_conf->sync_pairs, attr_ldap_sync_dn,
                                                     sync_conf->base_dn, strlen(sync_conf->base_dn), false);
                if (!vp) return -1;
 
                fr_pair_list_append_by_da_parent(sync_conf, vp, &sync_conf->sync_pairs, attr_ldap_sync_scope,
                                                 (uint32_t)sync_conf->scope, false);
                if (!vp) return -1;
 
                if (sync_conf->filter) {
                        fr_pair_list_append_by_da_parent_len(sync_conf, vp, &sync_conf->sync_pairs, attr_ldap_sync_filter,
                                                             sync_conf->filter, strlen(sync_conf->filter), false);
                        if (!vp) return -1;
                }
        }
 
        return 0;
}
 
fr_app_t proto_ldap_sync = {
        .common = {
                .magic          = MODULE_MAGIC_INIT,
                .name           = "ldap_sync",
                .config         = proto_ldap_sync_config,
                .inst_size      = sizeof(proto_ldap_sync_t),
                .instantiate    = mod_instantiate
        },
 
        .dict           = &dict_ldap_sync,
 
        .open           = mod_open,
        .decode         = mod_decode,
        .encode         = mod_encode,
};