rlm_radius.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: dc2d89dbd0b4937fd8c4e415226ad33bf7546992 $
 * @file rlm_radius.c
 * @brief A RADIUS client library.
 *
 * @copyright 2016 The FreeRADIUS server project
 * @copyright 2016 Network RADIUS SAS
 */
RCSID("$Id: dc2d89dbd0b4937fd8c4e415226ad33bf7546992 $")
 
#include <freeradius-devel/io/application.h>
#include <freeradius-devel/server/modpriv.h>
#include <freeradius-devel/unlang/xlat_func.h>
#include <freeradius-devel/util/debug.h>
#include <freeradius-devel/util/dlist.h>
 
#include "rlm_radius.h"
 
static int mode_parse(TALLOC_CTX *ctx, void *out, UNUSED void *parent, CONF_ITEM *ci, conf_parser_t const *rule);
static int type_parse(TALLOC_CTX *ctx, void *out, UNUSED void *parent, CONF_ITEM *ci, conf_parser_t const *rule);
static int status_check_type_parse(TALLOC_CTX *ctx, void *out, UNUSED void *parent, CONF_ITEM *ci, conf_parser_t const *rule);
static int status_check_update_parse(TALLOC_CTX *ctx, void *out, UNUSED void *parent, CONF_ITEM *ci, conf_parser_t const *rule);
static int radius_fixups(rlm_radius_t const *inst, request_t *request);
 
static conf_parser_t const status_check_config[] = {
        { FR_CONF_OFFSET_TYPE_FLAGS("type", FR_TYPE_VOID, 0, rlm_radius_t, status_check),
          .func = status_check_type_parse },
 
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t const status_check_update_config[] = {
        { FR_CONF_OFFSET_TYPE_FLAGS("update", FR_TYPE_VOID, CONF_FLAG_SUBSECTION | CONF_FLAG_REQUIRED, rlm_radius_t, status_check_map),
          .name2 = CF_IDENT_ANY,
          .func = status_check_update_parse },
        { FR_CONF_OFFSET("num_answers_to_alive", rlm_radius_t, num_answers_to_alive), .dflt = STRINGIFY(3) },
 
        CONF_PARSER_TERMINATOR
};
 
/*
 *      Retransmission intervals for the packets we support.
 */
static conf_parser_t auth_config[] = {
        { FR_CONF_OFFSET("initial_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_ACCESS_REQUEST].irt), .dflt = STRINGIFY(2) },
        { FR_CONF_OFFSET("max_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_ACCESS_REQUEST].mrt), .dflt = STRINGIFY(16) },
        { FR_CONF_OFFSET("max_rtx_count", rlm_radius_t, retry[FR_RADIUS_CODE_ACCESS_REQUEST].mrc), .dflt = STRINGIFY(5) },
        { FR_CONF_OFFSET("max_rtx_duration", rlm_radius_t, retry[FR_RADIUS_CODE_ACCESS_REQUEST].mrd), .dflt = STRINGIFY(30) },
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t acct_config[] = {
        { FR_CONF_OFFSET("initial_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].irt), .dflt = STRINGIFY(2) },
        { FR_CONF_OFFSET("max_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].mrt), .dflt = STRINGIFY(5) },
        { FR_CONF_OFFSET("max_rtx_count", rlm_radius_t, retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].mrc), .dflt = STRINGIFY(1) },
        { FR_CONF_OFFSET("max_rtx_duration", rlm_radius_t, retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].mrd), .dflt = STRINGIFY(30) },
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t status_config[] = {
        { FR_CONF_OFFSET("initial_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_STATUS_SERVER].irt), .dflt = STRINGIFY(2) },
        { FR_CONF_OFFSET("max_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_STATUS_SERVER].mrt), .dflt = STRINGIFY(5) },
        { FR_CONF_OFFSET("max_rtx_count", rlm_radius_t, retry[FR_RADIUS_CODE_STATUS_SERVER].mrc), .dflt = STRINGIFY(5) },
        { FR_CONF_OFFSET("max_rtx_duration", rlm_radius_t, retry[FR_RADIUS_CODE_STATUS_SERVER].mrd), .dflt = STRINGIFY(30) },
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t coa_config[] = {
        { FR_CONF_OFFSET("initial_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_COA_REQUEST].irt), .dflt = STRINGIFY(2) },
        { FR_CONF_OFFSET("max_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_COA_REQUEST].mrt), .dflt = STRINGIFY(16) },
        { FR_CONF_OFFSET("max_rtx_count", rlm_radius_t, retry[FR_RADIUS_CODE_COA_REQUEST].mrc), .dflt = STRINGIFY(5) },
        { FR_CONF_OFFSET("max_rtx_duration", rlm_radius_t, retry[FR_RADIUS_CODE_COA_REQUEST].mrd), .dflt = STRINGIFY(30) },
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t disconnect_config[] = {
        { FR_CONF_OFFSET("initial_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].irt), .dflt = STRINGIFY(2) },
        { FR_CONF_OFFSET("max_rtx_time", rlm_radius_t, retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].mrt), .dflt = STRINGIFY(16) },
        { FR_CONF_OFFSET("max_rtx_count", rlm_radius_t, retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].mrc), .dflt = STRINGIFY(5) },
        { FR_CONF_OFFSET("max_rtx_duration", rlm_radius_t, retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].mrd), .dflt = STRINGIFY(30) },
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t const transport_config[] = {
        { FR_CONF_OFFSET_FLAGS("secret", CONF_FLAG_REQUIRED, rlm_radius_t, secret) },
 
        CONF_PARSER_TERMINATOR
};
 
/*
 *      We only parse the pool options if we're connected.
 */
static conf_parser_t const connected_config[] = {
        { FR_CONF_POINTER("status_check", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) status_check_config },
 
        { FR_CONF_OFFSET_SUBSECTION("pool", 0, rlm_radius_t, trunk_conf, trunk_config ) },
 
        { FR_CONF_POINTER("udp", 0, CONF_FLAG_SUBSECTION | CONF_FLAG_OPTIONAL, NULL), .subcs = (void const *) transport_config },
 
        { FR_CONF_POINTER("tcp", 0, CONF_FLAG_SUBSECTION | CONF_FLAG_OPTIONAL, NULL), .subcs = (void const *) transport_config },
 
        CONF_PARSER_TERMINATOR
};
 
/*
 *      We only parse the pool options if we're connected.
 */
static conf_parser_t const pool_config[] = {
        { FR_CONF_POINTER("status_check", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) status_check_config },
 
        { FR_CONF_OFFSET_SUBSECTION("pool", 0, rlm_radius_t, trunk_conf, trunk_config ) },
 
        CONF_PARSER_TERMINATOR
};
 
/*
 *      A mapping of configuration file names to internal variables.
 */
static conf_parser_t const module_config[] = {
        { FR_CONF_OFFSET_FLAGS("mode", CONF_FLAG_REQUIRED, rlm_radius_t, mode), .func = mode_parse, .dflt = "proxy" },
 
        { FR_CONF_OFFSET_REF(rlm_radius_t, fd_config, fr_bio_fd_client_config) },
 
        { FR_CONF_OFFSET_FLAGS("type", CONF_FLAG_NOT_EMPTY | CONF_FLAG_MULTI | CONF_FLAG_REQUIRED, rlm_radius_t, types),
          .func = type_parse },
 
        { FR_CONF_OFFSET_FLAGS("replicate", CONF_FLAG_DEPRECATED, rlm_radius_t, replicate) },
 
        { FR_CONF_OFFSET_FLAGS("synchronous", CONF_FLAG_DEPRECATED, rlm_radius_t, synchronous) },
 
        { FR_CONF_OFFSET_FLAGS("originate", CONF_FLAG_DEPRECATED, rlm_radius_t, originate) },
 
        { FR_CONF_OFFSET("max_packet_size", rlm_radius_t, max_packet_size), .dflt = "4096" },
        { FR_CONF_OFFSET("max_send_coalesce", rlm_radius_t, max_send_coalesce), .dflt = "1024" },
 
        { FR_CONF_OFFSET("max_attributes", rlm_radius_t, max_attributes), .dflt = STRINGIFY(RADIUS_MAX_ATTRIBUTES) },
 
        { FR_CONF_OFFSET("require_message_authenticator", rlm_radius_t, require_message_authenticator),
          .func = cf_table_parse_int,
          .uctx = &(cf_table_parse_ctx_t){ .table = fr_radius_require_ma_table, .len = &fr_radius_require_ma_table_len },
          .dflt = "no" },
 
        { FR_CONF_OFFSET("response_window", rlm_radius_t, response_window), .dflt = STRINGIFY(20) },
 
        { FR_CONF_OFFSET("zombie_period", rlm_radius_t, zombie_period), .dflt = STRINGIFY(40) },
 
        { FR_CONF_OFFSET("revive_interval", rlm_radius_t, revive_interval) },
 
        CONF_PARSER_TERMINATOR
};
 
static conf_parser_t const type_interval_config[FR_RADIUS_CODE_MAX] = {
        [FR_RADIUS_CODE_ACCESS_REQUEST] = { FR_CONF_POINTER("Access-Request", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) auth_config },
 
        [FR_RADIUS_CODE_ACCOUNTING_REQUEST] = { FR_CONF_POINTER("Accounting-Request", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) acct_config },
        [FR_RADIUS_CODE_STATUS_SERVER] = { FR_CONF_POINTER("Status-Server", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) status_config },
        [FR_RADIUS_CODE_COA_REQUEST] = { FR_CONF_POINTER("CoA-Request", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) coa_config },
        [FR_RADIUS_CODE_DISCONNECT_REQUEST] = { FR_CONF_POINTER("Disconnect-Request", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) disconnect_config },
};
 
static fr_dict_t const *dict_radius;
 
extern fr_dict_autoload_t rlm_radius_dict[];
fr_dict_autoload_t rlm_radius_dict[] = {
        { .out = &dict_radius, .proto = "radius" },
        { NULL }
};
 
static fr_dict_attr_t const *attr_chap_challenge;
static fr_dict_attr_t const *attr_chap_password;
static fr_dict_attr_t const *attr_packet_type;
static fr_dict_attr_t const *attr_proxy_state;
 
static fr_dict_attr_t const *attr_error_cause;
static fr_dict_attr_t const *attr_event_timestamp;
static fr_dict_attr_t const *attr_extended_attribute_1;
static fr_dict_attr_t const *attr_message_authenticator;
static fr_dict_attr_t const *attr_eap_message;
static fr_dict_attr_t const *attr_nas_identifier;
static fr_dict_attr_t const *attr_original_packet_code;
static fr_dict_attr_t const *attr_response_length;
static fr_dict_attr_t const *attr_user_password;
 
extern fr_dict_attr_autoload_t rlm_radius_dict_attr[];
fr_dict_attr_autoload_t rlm_radius_dict_attr[] = {
        { .out = &attr_chap_challenge, .name = "CHAP-Challenge", .type = FR_TYPE_OCTETS, .dict = &dict_radius},
        { .out = &attr_chap_password, .name = "CHAP-Password", .type = FR_TYPE_OCTETS, .dict = &dict_radius},
        { .out = &attr_packet_type, .name = "Packet-Type", .type = FR_TYPE_UINT32, .dict = &dict_radius },
        { .out = &attr_proxy_state, .name = "Proxy-State", .type = FR_TYPE_OCTETS, .dict = &dict_radius},
 
        { .out = &attr_error_cause, .name = "Error-Cause", .type = FR_TYPE_UINT32, .dict = &dict_radius },
        { .out = &attr_event_timestamp, .name = "Event-Timestamp", .type = FR_TYPE_DATE, .dict = &dict_radius},
        { .out = &attr_extended_attribute_1, .name = "Extended-Attribute-1", .type = FR_TYPE_TLV, .dict = &dict_radius},
        { .out = &attr_message_authenticator, .name = "Message-Authenticator", .type = FR_TYPE_OCTETS, .dict = &dict_radius},
        { .out = &attr_eap_message, .name = "EAP-Message", .type = FR_TYPE_OCTETS, .dict = &dict_radius},
        { .out = &attr_nas_identifier, .name = "NAS-Identifier", .type = FR_TYPE_STRING, .dict = &dict_radius},
        { .out = &attr_original_packet_code, .name = "Extended-Attribute-1.Original-Packet-Code", .type = FR_TYPE_UINT32, .dict = &dict_radius},
        { .out = &attr_response_length, .name = "Extended-Attribute-1.Response-Length", .type = FR_TYPE_UINT32, .dict = &dict_radius },
        { .out = &attr_user_password, .name = "User-Password", .type = FR_TYPE_STRING, .dict = &dict_radius},
 
        { NULL }
};
 
#include "bio.c"
 
static fr_table_num_sorted_t mode_names[] = {
        { L("client"),          RLM_RADIUS_MODE_CLIENT          },
        { L("dynamic-proxy"),   RLM_RADIUS_MODE_XLAT_PROXY      },
        { L("proxy"),           RLM_RADIUS_MODE_PROXY           },
        { L("replicate"),       RLM_RADIUS_MODE_REPLICATE       },
        { L("unconnected-replicate"),   RLM_RADIUS_MODE_UNCONNECTED_REPLICATE   },
};
static size_t mode_names_len = NUM_ELEMENTS(mode_names);
 
 
/** Set the mode of operation
 *
 * @param[in] ctx       to allocate data in (instance of rlm_radius).
 * @param[out] out      Where to write the parsed data.
 * @param[in] parent    Base structure address.
 * @param[in] ci        #CONF_PAIR specifying the name of the type module.
 * @param[in] rule      unused.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int mode_parse(UNUSED TALLOC_CTX *ctx, void *out, void *parent,
                      CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        char const              *name = cf_pair_value(cf_item_to_pair(ci));
        rlm_radius_mode_t       mode;
        rlm_radius_t            *inst = talloc_get_type_abort(parent, rlm_radius_t);
        CONF_SECTION            *cs = cf_item_to_section(cf_parent(ci));
 
        mode = fr_table_value_by_str(mode_names, name, RLM_RADIUS_MODE_INVALID);
 
        /*
         *      Commented out until we upgrade the old configurations.
         */
        if (mode == RLM_RADIUS_MODE_INVALID) {
                cf_log_err(ci, "Invalid mode name \"%s\"", name);
                return -1;
        }
 
        *(rlm_radius_mode_t *) out = mode;
 
        /*
         *      Normally we want connected sockets, in which case we push additional configuration for
         *      connected sockets.
         */
        switch (mode) {
        default:
                inst->fd_config.type = FR_BIO_FD_CONNECTED;
 
                if (cf_section_rules_push(cs, connected_config) < 0) return -1;
                break;
 
        case RLM_RADIUS_MODE_XLAT_PROXY:
                inst->fd_config.type = FR_BIO_FD_UNCONNECTED; /* reset later when the home server is allocated */
 
                if (cf_section_rules_push(cs, pool_config) < 0) return -1;
                break;
 
        case RLM_RADIUS_MODE_UNCONNECTED_REPLICATE:
                inst->fd_config.type = FR_BIO_FD_UNCONNECTED;
                break;
        }
 
        return 0;
}
 
 
/** Set which types of packets we can parse
 *
 * @param[in] ctx       to allocate data in (instance of rlm_radius).
 * @param[out] out      Where to write the parsed data.
 * @param[in] parent    Base structure address.
 * @param[in] ci        #CONF_PAIR specifying the name of the type module.
 * @param[in] rule      unused.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int type_parse(UNUSED TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                      CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        char const              *type_str = cf_pair_value(cf_item_to_pair(ci));
        CONF_SECTION            *cs = cf_item_to_section(cf_parent(ci));
        fr_dict_enum_value_t const      *type_enum;
        uint32_t                code;
 
        /*
         *      Must be the RADIUS module
         */
        fr_assert(cs && (strcmp(cf_section_name1(cs), "radius") == 0));
 
        /*
         *      Allow the process module to be specified by
         *      packet type.
         */
        type_enum = fr_dict_enum_by_name(attr_packet_type, type_str, -1);
        if (!type_enum) {
        invalid_code:
                cf_log_err(ci, "Unknown or invalid RADIUS packet type '%s'", type_str);
                return -1;
        }
 
        code = type_enum->value->vb_uint32;
 
        /*
         *      Status-Server packets cannot be proxied.
         */
        if (code == FR_RADIUS_CODE_STATUS_SERVER) {
                cf_log_err(ci, "Invalid setting of 'type = Status-Server'.  Status-Server packets cannot be proxied.");
                return -1;
        }
 
        if (!code ||
            (code >= FR_RADIUS_CODE_MAX) ||
            (!type_interval_config[code].name1)) goto invalid_code;
 
        /*
         *      If we're doing async proxying, push the timers for the
         *      various packet types.
         */
        cf_section_rule_push(cs, &type_interval_config[code]);
 
        *(uint32_t *) out = code;
 
        return 0;
}
 
/** Allow for Status-Server ping checks
 *
 * @param[in] ctx       to allocate data in (instance of proto_radius).
 * @param[out] out      Where to write our parsed data.
 * @param[in] parent    Base structure address.
 * @param[in] ci        #CONF_PAIR specifying the name of the type module.
 * @param[in] rule      unused.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int status_check_type_parse(UNUSED TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                                   CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        char const              *type_str = cf_pair_value(cf_item_to_pair(ci));
        CONF_SECTION            *cs = cf_item_to_section(cf_parent(ci));
        fr_dict_enum_value_t const      *type_enum;
        uint32_t                code;
 
        /*
         *      Allow the process module to be specified by
         *      packet type.
         */
        type_enum = fr_dict_enum_by_name(attr_packet_type, type_str, -1);
        if (!type_enum) {
        invalid_code:
                cf_log_err(ci, "Unknown or invalid RADIUS packet type '%s'", type_str);
                return -1;
        }
 
        code = type_enum->value->vb_uint32;
 
        /*
         *      Cheat, and reuse the "type" array for allowed packet
         *      types.
         */
        if (!code ||
            (code >= FR_RADIUS_CODE_MAX) ||
            (!type_interval_config[code].name1)) goto invalid_code;
 
        /*
         *      Add irt / mrt / mrd / mrc parsing, in the parent
         *      configuration section.
         */
        cf_section_rule_push(cf_item_to_section(cf_parent(cs)), &type_interval_config[code]);
 
        memcpy(out, &code, sizeof(code));
 
        /*
         *      Nothing more to do here, so we stop.
         */
        if (code == FR_RADIUS_CODE_STATUS_SERVER) return 0;
 
        cf_section_rule_push(cs, status_check_update_config);
 
        return 0;
}
 
/** Allow the admin to set packet contents for Status-Server ping checks
 *
 * @param[in] ctx       to allocate data in (instance of proto_radius).
 * @param[out] out      Where to write our parsed data
 * @param[in] parent    Base structure address.
 * @param[in] ci        #CONF_SECTION specifying the things to update
 * @param[in] rule      unused.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
static int status_check_update_parse(TALLOC_CTX *ctx, void *out, UNUSED void *parent,
                                     CONF_ITEM *ci, UNUSED conf_parser_t const *rule)
{
        int                     rcode;
        CONF_SECTION            *cs;
        char const              *name2;
        map_list_t              *head = (map_list_t *)out;
 
        fr_assert(cf_item_is_section(ci));
        map_list_init(head);
 
        cs = cf_item_to_section(ci);
        name2 = cf_section_name2(cs);
        if (!name2 || (strcmp(name2, "request") != 0)) {
                cf_log_err(cs, "You must specify 'request' as the destination list");
                return -1;
        }
 
        /*
         *      Compile the "update" section.
         */
        {
                tmpl_rules_t    parse_rules = {
                        .attr = {
                                .dict_def = dict_radius,
                        }
                };
 
                rcode = map_afrom_cs(ctx, head, cs, &parse_rules, &parse_rules, unlang_fixup_update, NULL, 128);
                if (rcode < 0) return -1; /* message already printed */
                if (map_list_empty(head)) {
                        cf_log_err(cs, "'update' sections cannot be empty");
                        return -1;
                }
        }
 
        /*
         *      Rely on "bootstrap" to do sanity checks between 'type
         *      = Access-Request', and 'update' containing passwords.
         */
        return 0;
}
 
 
/** Do any RADIUS-layer fixups for proxying.
 *
 */
static int radius_fixups(rlm_radius_t const *inst, request_t *request)
{
        fr_pair_t *vp;
 
        if (request->packet->code == FR_RADIUS_CODE_STATUS_SERVER) {
                RWDEBUG("Status-Server is reserved for internal use, and cannot be sent manually.");
                return 0;
        }
 
        if (!inst->allowed[request->packet->code]) {
                REDEBUG("Packet code %s is disallowed by the configuration",
                       fr_radius_packet_name[request->packet->code]);
                return -1;
        }
 
        /*
         *      Check for proxy loops.
         *
         *      There should _never_ be two instances of the same Proxy-State in the packet.
         */
        if ((inst->mode == RLM_RADIUS_MODE_PROXY) && RDEBUG_ENABLED) {
                unsigned int count = 0;
                fr_dcursor_t cursor;
 
                for (vp = fr_pair_dcursor_by_da_init(&cursor, &request->request_pairs, attr_proxy_state);
                     vp;
                     vp = fr_dcursor_next(&cursor)) {
                        if (vp->vp_length != sizeof(inst->common_ctx.proxy_state)) continue;
 
                        if (memcmp(vp->vp_octets, &inst->common_ctx.proxy_state,
                                   sizeof(inst->common_ctx.proxy_state)) == 0) {
 
                                /*
                                 *      Cancel proxying when there are two instances of the same Proxy-State
                                 *      in the packet.  This limitation could be configurable, but it likely
                                 *      doesn't make sense to make it configurable.
                                 */
                                if (count == 1) {
                                        RWARN("Canceling proxy due to loop of multiple %pV", vp);
                                        return -1;
                                }
 
                                RWARN("Proxied packet contains our own %pV", vp);
                                RWARN("Check if there is a proxy loop.  Perhaps the server has been configured to proxy to itself.");
                                count++;
                        }
                }
        }
 
        if (request->packet->code != FR_RADIUS_CODE_ACCESS_REQUEST) return 0;
 
        if (fr_pair_find_by_da(&request->request_pairs, NULL, attr_chap_password) &&
            !fr_pair_find_by_da(&request->request_pairs, NULL, attr_chap_challenge)) {
                MEM(pair_append_request(&vp, attr_chap_challenge) >= 0);
                fr_pair_value_memdup(vp, request->packet->vector, sizeof(request->packet->vector), true);
        }
 
        return 0;
}
 
 
/** Send packets outbound.
 *
 */
static unlang_action_t CC_HINT(nonnull) mod_process(rlm_rcode_t *p_result, module_ctx_t const *mctx, request_t *request)
{
        rlm_radius_t const      *inst = talloc_get_type_abort_const(mctx->mi->data, rlm_radius_t);
        bio_thread_t            *thread = talloc_get_type_abort(mctx->thread, bio_thread_t);
        fr_client_t             *client;
        int                     rcode;
        bio_request_t           *u = NULL;
        fr_retry_config_t const *retry_config = NULL;
 
        if (!request->packet->code) {
                REDEBUG("You MUST specify a packet code");
                RETURN_MODULE_FAIL;
        }
 
        if ((request->packet->code >= FR_RADIUS_CODE_MAX) ||
            !fr_time_delta_ispos(inst->retry[request->packet->code].irt)) { /* can't be zero */
                REDEBUG("Invalid packet code %u", request->packet->code);
                RETURN_MODULE_FAIL;
        }
 
        /*
         *      Unconnected sockets use %radius.replicate(ip, port, secret),
         *      or %radius.sendto(ip, port, secret)
         */
        if ((inst->mode == RLM_RADIUS_MODE_UNCONNECTED_REPLICATE) ||
            (inst->mode == RLM_RADIUS_MODE_XLAT_PROXY)) {
                REDEBUG("When using 'mode = unconnected-*', this module cannot be used in-place.  Instead, it must be called via a function call");
                RETURN_MODULE_FAIL;
        }
 
        client = client_from_request(request);
        if (client && client->dynamic && !client->active) {
                REDEBUG("Cannot proxy packets which define dynamic clients");
                RETURN_MODULE_FAIL;
        }
 
        /*
         *      Push the request and it's data to the IO submodule.
         *
         *      This may return YIELD, for "please yield", or it may
         *      return another code which indicates what happened to
         *      the request...
         */
        rcode = mod_enqueue(&u, &retry_config, inst, thread->ctx.trunk, request);
        if (rcode == 0) RETURN_MODULE_NOOP;
        if (rcode < 0) RETURN_MODULE_FAIL;
 
        return unlang_module_yield_to_retry(request, mod_resume, mod_retry, mod_signal, 0, u, retry_config);
}
 
 
static int mod_instantiate(module_inst_ctx_t const *mctx)
{
        size_t i, num_types;
        rlm_radius_t *inst = talloc_get_type_abort(mctx->mi->data, rlm_radius_t);
        CONF_SECTION *conf = mctx->mi->conf;
 
        inst->name = mctx->mi->name;
        inst->received_message_authenticator = talloc_zero(NULL, bool);         /* Allocated outside of inst to default protection */
 
        /*
         *      Allow explicit setting of mode.
         */
        if (inst->mode != RLM_RADIUS_MODE_INVALID) goto check_others;
 
        /*
         *      If not set, try to insinuate it from context.
         */
        if (inst->replicate) {
                if (inst->originate) {
                        cf_log_err(conf, "Cannot set 'replicate=true' and 'originate=true' at the same time.");
                        return -1;
                }
 
                if (inst->synchronous) {
                        cf_log_warn(conf, "Ignoring 'synchronous=true' due to 'replicate=true'");
                }
 
                inst->mode = RLM_RADIUS_MODE_REPLICATE;
                goto check_others;
        }
 
        /*
         *      Argubly we should be allowed to do synchronous proxying _and_ originating client packets.
         *
         *      However, the previous code didn't really do that consistently.
         */
        if (inst->synchronous && inst->originate) {
                cf_log_err(conf, "Cannot set 'synchronous=true' and 'originate=true'");
                return -1;
        }
 
        if (inst->synchronous) {
                inst->mode = RLM_RADIUS_MODE_PROXY;
        } else {
                inst->mode = RLM_RADIUS_MODE_CLIENT;
        }
 
check_others:
        /*
         *      Replication is write-only, and append by default.
         */
        if (inst->mode == RLM_RADIUS_MODE_REPLICATE) {
                if (inst->fd_config.filename && (inst->fd_config.flags != O_WRONLY)) {
                        cf_log_info(conf, "Setting 'flags = write-only' for writing to a file");
                }
                inst->fd_config.flags = O_WRONLY | O_APPEND;
 
        } else if (inst->fd_config.filename) {
                cf_log_err(conf, "When using an output 'filename', you MUST set 'mode = replicate'");
                return -1;
 
        } else {
                /*
                 *      All other IO is read+write.
                 */
                inst->fd_config.flags = O_RDWR;
        }
 
        if (fr_bio_fd_check_config(&inst->fd_config) < 0) {
                cf_log_perr(conf, "Invalid configuration");
                return -1;
        }
 
        /*
         *      Clamp max_packet_size first before checking recv_buff and send_buff
         */
        FR_INTEGER_BOUND_CHECK("max_packet_size", inst->max_packet_size, >=, 64);
        FR_INTEGER_BOUND_CHECK("max_packet_size", inst->max_packet_size, <=, 65535);
 
        if (inst->mode != RLM_RADIUS_MODE_UNCONNECTED_REPLICATE) {
                /*
                 *      These limits are specific to RADIUS, and cannot be over-ridden
                 */
                FR_INTEGER_BOUND_CHECK("trunk.per_connection_max", inst->trunk_conf.max_req_per_conn, >=, 2);
                FR_INTEGER_BOUND_CHECK("trunk.per_connection_max", inst->trunk_conf.max_req_per_conn, <=, 255);
                FR_INTEGER_BOUND_CHECK("trunk.per_connection_target", inst->trunk_conf.target_req_per_conn, <=, inst->trunk_conf.max_req_per_conn / 2);
        }
 
        if ((inst->mode == RLM_RADIUS_MODE_UNCONNECTED_REPLICATE) ||
            (inst->mode == RLM_RADIUS_MODE_XLAT_PROXY)) {
                if (inst->fd_config.src_port != 0) {
                        cf_log_err(conf, "Cannot set 'src_port' when using this 'mode'");
                        return -1;
                }
        }
 
        FR_TIME_DELTA_BOUND_CHECK("response_window", inst->zombie_period, >=, fr_time_delta_from_sec(1));
        FR_TIME_DELTA_BOUND_CHECK("response_window", inst->zombie_period, <=, fr_time_delta_from_sec(120));
 
        FR_TIME_DELTA_BOUND_CHECK("zombie_period", inst->zombie_period, >=, fr_time_delta_from_sec(1));
        FR_TIME_DELTA_BOUND_CHECK("zombie_period", inst->zombie_period, <=, fr_time_delta_from_sec(120));
 
        if (!inst->status_check) {
                FR_TIME_DELTA_BOUND_CHECK("revive_interval", inst->revive_interval, >=, fr_time_delta_from_sec(10));
                FR_TIME_DELTA_BOUND_CHECK("revive_interval", inst->revive_interval, <=, fr_time_delta_from_sec(3600));
        }
 
        num_types = talloc_array_length(inst->types);
        fr_assert(num_types > 0);
 
        inst->timeout_retry = (fr_retry_config_t) {
                .mrc = 1,
                .mrd = inst->response_window,
        };
 
        inst->common_ctx = (fr_radius_ctx_t) {
                .secret = inst->secret,
                .secret_length = inst->secret ? talloc_array_length(inst->secret) - 1 : 0,
                .proxy_state = ((uint64_t) fr_rand()) << 32 | fr_rand(),
        };
 
        /*
         *      Allow for O(1) lookup later...
         */
        for (i = 0; i < num_types; i++) {
                uint32_t code;
 
                code = inst->types[i];
                fr_assert(code > 0);
                fr_assert(code < FR_RADIUS_CODE_MAX);
 
                inst->allowed[code] = true;
        }
 
        fr_assert(inst->status_check < FR_RADIUS_CODE_MAX);
 
        /*
         *      If we're replicating, we don't care if the other end
         *      is alive.
         */
        if (inst->status_check) {
                if (inst->mode == RLM_RADIUS_MODE_REPLICATE) {
                        cf_log_warn(conf, "Ignoring 'status_check = %s' due to 'mode = replicate'",
                                    fr_radius_packet_name[inst->status_check]);
                        inst->status_check = false;
 
                } else if ((inst->mode == RLM_RADIUS_MODE_UNCONNECTED_REPLICATE) ||
                           (inst->mode == RLM_RADIUS_MODE_XLAT_PROXY)) {
                                   cf_log_warn(conf, "Ignoring 'status_check = %s' due to 'mode' setting",
                                    fr_radius_packet_name[inst->status_check]);
                        inst->status_check = false;
                }
        }
 
        /*
         *      If we have status checks, then do some sanity checks.
         *      Status-Server is always allowed.  Otherwise, the
         *      status checks have to match one of the allowed
         *      packets.
         */
        if (inst->status_check) {
                if (inst->status_check == FR_RADIUS_CODE_STATUS_SERVER) {
                        inst->allowed[inst->status_check] = true;
 
                } else if (!inst->allowed[inst->status_check]) {
                        cf_log_err(conf, "Using 'status_check = %s' requires also 'type = %s'",
                                   fr_radius_packet_name[inst->status_check], fr_radius_packet_name[inst->status_check]);
                        return -1;
                }
 
                /*
                 *      @todo - check the contents of the "update"
                 *      section, to be sure that (e.g.) Access-Request
                 *      contains User-Name, etc.
                 */
 
                if (inst->fd_config.filename) {
                        cf_log_info(conf, "Disabling status checks for output file %s", inst->fd_config.filename);
                        inst->status_check = 0;
                }
        }
 
        /*
         *      Files and unix sockets can just have us call write().
         */
        if (inst->fd_config.filename || inst->fd_config.path) {
                inst->max_send_coalesce = 1;
        }
 
        inst->trunk_conf.req_pool_headers = 4;  /* One for the request, one for the buffer, one for the tracking binding, one for Proxy-State VP */
        inst->trunk_conf.req_pool_size = 1024 + sizeof(fr_pair_t) + 20;
 
        /*
         *      Only check the async timers when we're acting as a client.
         */
        if (inst->mode != RLM_RADIUS_MODE_CLIENT) {
                return 0;
        }
 
        /*
         *      Set limits on retransmission timers
         */
        if (inst->allowed[FR_RADIUS_CODE_ACCESS_REQUEST]) {
                FR_TIME_DELTA_BOUND_CHECK("Access-Request.initial_rtx_time", inst->retry[FR_RADIUS_CODE_ACCESS_REQUEST].irt, >=, fr_time_delta_from_sec(1));
                FR_TIME_DELTA_BOUND_CHECK("Access-Request.max_rtx_time", inst->retry[FR_RADIUS_CODE_ACCESS_REQUEST].mrt, >=, fr_time_delta_from_sec(5));
                FR_INTEGER_BOUND_CHECK("Access-Request.max_rtx_count", inst->retry[FR_RADIUS_CODE_ACCESS_REQUEST].mrc, >=, 1);
                FR_TIME_DELTA_BOUND_CHECK("Access-Request.max_rtx_duration", inst->retry[FR_RADIUS_CODE_ACCESS_REQUEST].mrd, >=, fr_time_delta_from_sec(5));
 
                FR_TIME_DELTA_BOUND_CHECK("Access-Request.initial_rtx_time", inst->retry[FR_RADIUS_CODE_ACCESS_REQUEST].irt, <=, fr_time_delta_from_sec(3));
                FR_TIME_DELTA_BOUND_CHECK("Access-Request.max_rtx_time", inst->retry[FR_RADIUS_CODE_ACCESS_REQUEST].mrt, <=, fr_time_delta_from_sec(30));
                FR_INTEGER_BOUND_CHECK("Access-Request.max_rtx_count", inst->retry[FR_RADIUS_CODE_ACCESS_REQUEST].mrc, <=, 10);
                FR_TIME_DELTA_BOUND_CHECK("Access-Request.max_rtx_duration", inst->retry[FR_RADIUS_CODE_ACCESS_REQUEST].mrd, <=, fr_time_delta_from_sec(30));
        }
 
        /*
         *      Note that RFC 5080 allows for Accounting-Request to
         *      have mrt=mrc=mrd = 0, which means "retransmit
         *      forever".  We allow that, with the restriction that
         *      the server core will automatically free the request at
         *      max_request_time.
         */
        if (inst->allowed[FR_RADIUS_CODE_ACCOUNTING_REQUEST]) {
                FR_TIME_DELTA_BOUND_CHECK("Accounting-Request.initial_rtx_time", inst->retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].irt, >=, fr_time_delta_from_sec(1));
#if 0
                FR_TIME_DELTA_BOUND_CHECK("Accounting-Request.max_rtx_time", inst->retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].mrt, >=, fr_time_delta_from_sec(5));
                FR_INTEGER_BOUND_CHECK("Accounting-Request.max_rtx_count", inst->retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].mrc, >=, 0);
                FR_TIME_DELTA_BOUND_CHECK("Accounting-Request.max_rtx_duration", inst->retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].mrd, >=, fr_time_delta_from_sec(0));
#endif
 
                FR_TIME_DELTA_BOUND_CHECK("Accounting-Request.initial_rtx_time", inst->retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].irt, <=, fr_time_delta_from_sec(3));
                FR_TIME_DELTA_BOUND_CHECK("Accounting-Request.max_rtx_time", inst->retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].mrt, <=, fr_time_delta_from_sec(30));
                FR_INTEGER_BOUND_CHECK("Accounting-Request.max_rtx_count", inst->retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].mrc, <=, 10);
                FR_TIME_DELTA_BOUND_CHECK("Accounting-Request.max_rtx_duration", inst->retry[FR_RADIUS_CODE_ACCOUNTING_REQUEST].mrd, <=, fr_time_delta_from_sec(30));
        }
 
        /*
         *      Status-Server
         */
        if (inst->allowed[FR_RADIUS_CODE_STATUS_SERVER]) {
                FR_TIME_DELTA_BOUND_CHECK("Status-Server.initial_rtx_time", inst->retry[FR_RADIUS_CODE_STATUS_SERVER].irt, >=, fr_time_delta_from_sec(1));
                FR_TIME_DELTA_BOUND_CHECK("Status-Server.max_rtx_time", inst->retry[FR_RADIUS_CODE_STATUS_SERVER].mrt, >=, fr_time_delta_from_sec(5));
                FR_INTEGER_BOUND_CHECK("Status-Server.max_rtx_count", inst->retry[FR_RADIUS_CODE_STATUS_SERVER].mrc, >=, 1);
                FR_TIME_DELTA_BOUND_CHECK("Status-Server.max_rtx_duration", inst->retry[FR_RADIUS_CODE_STATUS_SERVER].mrd, >=, fr_time_delta_from_sec(5));
 
                FR_TIME_DELTA_BOUND_CHECK("Status-Server.initial_rtx_time", inst->retry[FR_RADIUS_CODE_STATUS_SERVER].irt, <=, fr_time_delta_from_sec(3));
                FR_TIME_DELTA_BOUND_CHECK("Status-Server.max_rtx_time", inst->retry[FR_RADIUS_CODE_STATUS_SERVER].mrt, <=, fr_time_delta_from_sec(30));
                FR_INTEGER_BOUND_CHECK("Status-Server.max_rtx_count", inst->retry[FR_RADIUS_CODE_STATUS_SERVER].mrc, <=, 10);
                FR_TIME_DELTA_BOUND_CHECK("Status-Server.max_rtx_duration", inst->retry[FR_RADIUS_CODE_STATUS_SERVER].mrd, <=, fr_time_delta_from_sec(30));
        }
 
        /*
         *      CoA
         */
        if (inst->allowed[FR_RADIUS_CODE_COA_REQUEST]) {
                FR_TIME_DELTA_BOUND_CHECK("CoA-Request.initial_rtx_time", inst->retry[FR_RADIUS_CODE_COA_REQUEST].irt, >=, fr_time_delta_from_sec(1));
                FR_TIME_DELTA_BOUND_CHECK("CoA-Request.max_rtx_time", inst->retry[FR_RADIUS_CODE_COA_REQUEST].mrt, >=, fr_time_delta_from_sec(5));
                FR_INTEGER_BOUND_CHECK("CoA-Request.max_rtx_count", inst->retry[FR_RADIUS_CODE_COA_REQUEST].mrc, >=, 1);
                FR_TIME_DELTA_BOUND_CHECK("CoA-Request.max_rtx_duration", inst->retry[FR_RADIUS_CODE_COA_REQUEST].mrd, >=, fr_time_delta_from_sec(5));
 
                FR_TIME_DELTA_BOUND_CHECK("CoA-Request.initial_rtx_time", inst->retry[FR_RADIUS_CODE_COA_REQUEST].irt, <=, fr_time_delta_from_sec(3));
                FR_TIME_DELTA_BOUND_CHECK("CoA-Request.max_rtx_time", inst->retry[FR_RADIUS_CODE_COA_REQUEST].mrt, <=, fr_time_delta_from_sec(60));
                FR_INTEGER_BOUND_CHECK("CoA-Request.max_rtx_count", inst->retry[FR_RADIUS_CODE_COA_REQUEST].mrc, <=, 10);
                FR_TIME_DELTA_BOUND_CHECK("CoA-Request.max_rtx_duration", inst->retry[FR_RADIUS_CODE_COA_REQUEST].mrd, <=, fr_time_delta_from_sec(30));
        }
 
        /*
         *      Disconnect
         */
        if (inst->allowed[FR_RADIUS_CODE_DISCONNECT_REQUEST]) {
                FR_TIME_DELTA_BOUND_CHECK("Disconnect-Request.initial_rtx_time", inst->retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].irt, >=, fr_time_delta_from_sec(1));
                FR_TIME_DELTA_BOUND_CHECK("Disconnect-Request.max_rtx_time", inst->retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].mrt, >=, fr_time_delta_from_sec(5));
                FR_INTEGER_BOUND_CHECK("Disconnect-Request.max_rtx_count", inst->retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].mrc, >=, 1);
                FR_TIME_DELTA_BOUND_CHECK("Disconnect-Request.max_rtx_duration", inst->retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].mrd, >=, fr_time_delta_from_sec(5));
 
                FR_TIME_DELTA_BOUND_CHECK("Disconnect-Request.initial_rtx_time", inst->retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].irt, <=, fr_time_delta_from_sec(3));
                FR_TIME_DELTA_BOUND_CHECK("Disconnect-Request.max_rtx_time", inst->retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].mrt, <=, fr_time_delta_from_sec(30));
                FR_INTEGER_BOUND_CHECK("Disconnect-Request.max_rtx_count", inst->retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].mrc, <=, 10);
                FR_TIME_DELTA_BOUND_CHECK("Disconnect-Request.max_rtx_duration", inst->retry[FR_RADIUS_CODE_DISCONNECT_REQUEST].mrd, <=, fr_time_delta_from_sec(30));
        }
 
        return 0;
}
 
static int mod_bootstrap(module_inst_ctx_t const *mctx)
{
        xlat_t          *xlat;
        rlm_radius_t const *inst = talloc_get_type_abort(mctx->mi->data, rlm_radius_t);
 
        switch (inst->mode) {
        case RLM_RADIUS_MODE_UNCONNECTED_REPLICATE:
                xlat = module_rlm_xlat_register(mctx->mi->boot, mctx, "sendto.ipaddr", xlat_radius_replicate, FR_TYPE_VOID);
                xlat_func_args_set(xlat, xlat_radius_send_args);
                break;
 
        case RLM_RADIUS_MODE_XLAT_PROXY:
                xlat = module_rlm_xlat_register(mctx->mi->boot, mctx, "sendto.ipaddr", xlat_radius_client, FR_TYPE_UINT32);
                xlat_func_args_set(xlat, xlat_radius_send_args);
                break;
 
        default:
                break;
        }
 
        return 0;
}
 
 
static int mod_detach(module_detach_ctx_t const *mctx)
{
        rlm_radius_t *inst = talloc_get_type_abort(mctx->mi->data, rlm_radius_t);
 
        talloc_free(inst->received_message_authenticator);
        return 0;
}
 
static int mod_load(void)
{
        if (fr_radius_global_init() < 0) {
                PERROR("Failed initialising protocol library");
                return -1;
        }
        return 0;
}
 
static void mod_unload(void)
{
        fr_radius_global_free();
}
 
/*
 *      The module name should be the only globally exported symbol.
 *      That is, everything else should be 'static'.
 *
 *      If the module needs to temporarily modify it's instantiation
 *      data, the type should be changed to MODULE_TYPE_THREAD_UNSAFE.
 *      The server will then take care of ensuring that the module
 *      is single-threaded.
 */
extern module_rlm_t rlm_radius;
module_rlm_t rlm_radius = {
        .common = {
                .magic          = MODULE_MAGIC_INIT,
                .name           = "radius",
                .inst_size      = sizeof(rlm_radius_t),
                .config         = module_config,
 
                .onload         = mod_load,
                .unload         = mod_unload,
 
                .bootstrap      = mod_bootstrap,
                .instantiate    = mod_instantiate,
                .detach         = mod_detach,
 
                .thread_inst_size       = sizeof(bio_thread_t),
                .thread_inst_type       = "bio_thread_t",
                .thread_instantiate     = mod_thread_instantiate,
        },
        .method_group = {
                .bindings = (module_method_binding_t[]){
                        { .section = SECTION_NAME(CF_IDENT_ANY, CF_IDENT_ANY), .method = mod_process },
                        MODULE_BINDING_TERMINATOR
                },
        }
};