client.c

Go to the documentation of this file.

/*
 *   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: 7b5f3dc09929f5996d10cebad77273d4e595f302 $
 * @file src/lib/server/client.c
 * @brief Manage clients allowed to communicate with the server.
 *
 * @copyright 2015 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 * @copyright 2000,2006 The FreeRADIUS server project
 * @copyright 2000 Alan DeKok (aland@freeradius.org)
 * @copyright 2000 Miquel van Smoorenburg (miquels@cistron.nl)
 */
RCSID("$Id: 7b5f3dc09929f5996d10cebad77273d4e595f302 $")
 
#include <freeradius-devel/protocol/freeradius/freeradius.internal.h>
#include <freeradius-devel/server/cf_file.h>
#include <freeradius-devel/server/cf_parse.h>
#include <freeradius-devel/server/client.h>
#include <freeradius-devel/server/main_config.h>
#include <freeradius-devel/server/module.h>
#include <freeradius-devel/server/virtual_servers.h>
#include <freeradius-devel/unlang/call.h>
 
#include <freeradius-devel/util/debug.h>
#include <freeradius-devel/util/base16.h>
#include <freeradius-devel/util/misc.h>
#include <freeradius-devel/util/trie.h>
 
#include <ctype.h>
#include <fcntl.h>
#include <sys/stat.h>
 
//#define WITH_TRIE (1)
 
/** Group of clients
 *
 */
struct fr_client_list_s {
        char const      *name;                  //!< Name of the client list.
#ifdef WITH_TRIE
        fr_trie_t       *v4_udp;
        fr_trie_t       *v6_udp;
        fr_trie_t       *v4_tcp;
        fr_trie_t       *v6_tcp;
#else
        fr_rb_tree_t    *tree[129];
#endif
};
 
static fr_client_list_t *root_clients = NULL;   //!< Global client list.
 
#ifndef WITH_TRIE
static int8_t client_cmp(void const *one, void const *two)
{
        int ret;
        fr_client_t const *a = one;
        fr_client_t const *b = two;
 
        ret = fr_ipaddr_cmp(&a->ipaddr, &b->ipaddr);
        if (ret != 0) return ret;
 
        /*
         *      0 is "wildcard", or "both" protocols
         */
        if ((a->proto == IPPROTO_IP) || (b->proto == IPPROTO_IP)) return 0;
 
        return CMP(a->proto, b->proto);
}
 
#endif
 
void client_list_free(void)
{
        TALLOC_FREE(root_clients);
}
 
/** Free a client
 *
 *  It's up to the caller to ensure that it's deleted from any fr_client_list_t.
 */
void client_free(fr_client_t *client)
{
        if (!client) return;
 
        talloc_free(client);
}
 
/** Return a new client list
 *
 * @note The container won't contain any clients.
 *
 * @return
 *      - New client list on success.
 *      - NULL on error (OOM).
 */
fr_client_list_t *client_list_init(CONF_SECTION *cs)
{
        fr_client_list_t *clients = talloc_zero(cs, fr_client_list_t);
 
        if (!clients) return NULL;
 
        clients->name = talloc_strdup(clients, cs ? cf_section_name1(cs) : "root");
 
#ifdef WITH_TRIE
        clients->v4_udp = fr_trie_alloc(clients, NULL, NULL);
        if (!clients->v4_udp) {
                talloc_free(clients);
                return NULL;
        }
 
        clients->v6_udp = fr_trie_alloc(clients, NULL, NULL);
        if (!clients->v6_udp) {
                talloc_free(clients);
                return NULL;
        }
 
        clients->v4_tcp = fr_trie_alloc(clients, NULL, NULL);
        if (!clients->v4_tcp) {
                talloc_free(clients);
                return NULL;
        }
 
        clients->v6_tcp = fr_trie_alloc(clients, NULL, NULL);
        if (!clients->v6_tcp) {
                talloc_free(clients);
                return NULL;
        }
#endif  /* WITH_TRIE */
 
        return clients;
}
 
#ifdef WITH_TRIE
/*
 *      @todo - either support client definitions where "proto = *",
 *      or update this code to allow for that.  i.e. we create yet
 *      another set of v4/v6 tries, for "proto = *" clients.  And then
 *      do lookups there, too.  Or, just unify the udp/tcp tries, and
 *      instead do post-processing?  Though those two clients can have
 *      different secrets... and the trie code doesn't allow 2
 *      fr_trie_user_t nodes in a row.  So we would have to instead
 *      handle that ourselves, with a wrapper around the fr_client_t
 *      structure that does udp/tcp/wildcard demultiplexing
 */
static fr_trie_t *clients_trie(fr_client_list_t const *clients, fr_ipaddr_t const *ipaddr,
                               int proto)
{
        if (ipaddr->af == AF_INET) {
                if (proto == IPPROTO_TCP) return clients->v4_tcp;
 
                return clients->v4_udp;
        }
 
        fr_assert(ipaddr->af == AF_INET6);
 
        if (proto == IPPROTO_TCP) return clients->v6_tcp;
 
        return clients->v6_udp;
}
#endif  /* WITH_TRIE */
 
/** Add a client to a fr_client_list_t
 *
 * @param clients list to add client to, may be NULL if global client list is being used.
 * @param client to add.
 * @return
 *      - true on success.
 *      - false on failure.
 */
bool client_add(fr_client_list_t *clients, fr_client_t *client)
{
#ifdef WITH_TRIE
        fr_trie_t *trie;
#else
#endif
        fr_client_t *old;
        char buffer[FR_IPADDR_PREFIX_STRLEN];
 
        if (!client) return false;
 
        /*
         *      Hack to fixup wildcard clients
         *
         *      If the IP is all zeros, with a 32 or 128 bit netmask
         *      assume the user meant to configure 0.0.0.0/0 instead
         *      of 0.0.0.0/32 - which would require the src IP of
         *      the client to be all zeros.
         */
        if (fr_ipaddr_is_inaddr_any(&client->ipaddr) == 1) switch (client->ipaddr.af) {
        case AF_INET:
                if (client->ipaddr.prefix == 32) client->ipaddr.prefix = 0;
                break;
 
        case AF_INET6:
                if (client->ipaddr.prefix == 128) client->ipaddr.prefix = 0;
                break;
 
        default:
                fr_assert(0);
        }
 
        fr_inet_ntop_prefix(buffer, sizeof(buffer), &client->ipaddr);
        DEBUG3("Adding client %s (%s) to prefix tree %i", buffer, client->longname, client->ipaddr.prefix);
 
        /*
         *      If "clients" is NULL, it means add to the global list,
         *      unless we're trying to add it to a virtual server...
         */
        if (!clients) {
                if (client->server != NULL) {
                        CONF_SECTION *cs;
                        CONF_SECTION *subcs;
 
                        if (!client->cs) {
                                ERROR("Failed to find configuration section in client.  Ignoring 'virtual_server' directive");
                                return false;
                        }
 
                        cs = cf_section_find(cf_root(client->cs), "server", client->server);
                        if (!cs) {
                                ERROR("Failed to find virtual server %s", client->server);
                                return false;
                        }
 
                        /*
                         *      If this server has no "listen" section, add the clients
                         *      to the global client list.
                         */
                        subcs = cf_section_find(cs, "listen", NULL);
                        if (!subcs) goto global_clients;
 
                        /*
                         *      If the client list already exists, use that.
                         *      Otherwise, create a new client list.
                         */
                        clients = cf_data_value(cf_data_find(cs, fr_client_list_t, NULL));
                        if (!clients) {
                                MEM(clients = client_list_init(cs));
                                if (!cf_data_add(cs, clients, NULL, true)) {
                                        ERROR("Failed to associate clients with virtual server %s", client->server);
                                        talloc_free(clients);
                                        return false;
                                }
                        }
 
                } else {
                global_clients:
                        /*
                         *      Initialize the global list, if not done already.
                         */
                        if (!root_clients) {
                                root_clients = client_list_init(NULL);
                                if (!root_clients) return false;
                        }
                        clients = root_clients;
                }
        }
 
#define namecmp(a) ((!old->a && !client->a) || (old->a && client->a && (strcmp(old->a, client->a) == 0)))
 
#ifdef WITH_TRIE
        trie = clients_trie(clients, &client->ipaddr, client->proto);
 
        /*
         *      Cannot insert the same client twice.
         */
        old = fr_trie_match_by_key(trie, &client->ipaddr.addr, client->ipaddr.prefix);
 
#else  /* WITH_TRIE */
 
        if (!clients->tree[client->ipaddr.prefix]) {
                clients->tree[client->ipaddr.prefix] = fr_rb_inline_talloc_alloc(clients, fr_client_t, node, client_cmp,
                                                                                 NULL);
                if (!clients->tree[client->ipaddr.prefix]) {
                        return false;
                }
        }
 
        old = fr_rb_find(clients->tree[client->ipaddr.prefix], client);
#endif
        if (old) {
                /*
                 *      If it's a complete duplicate, then free the new
                 *      one, and return "OK".
                 */
                if (namecmp(longname) && namecmp(secret) &&
                    namecmp(shortname) && namecmp(nas_type) &&
                    namecmp(server) &&
                    (old->message_authenticator == client->message_authenticator)) {
                        WARN("Ignoring duplicate client %s", client->longname);
                        client_free(client);
                        return true;
                }
 
                ERROR("Failed to add duplicate client %s", client->shortname);
                client_free(client);
                return false;
        }
#undef namecmp
 
#ifdef WITH_TRIE
        /*
         *      Other error adding client: likely is fatal.
         */
        if (fr_trie_insert_by_key(trie, &client->ipaddr.addr, client->ipaddr.prefix, client) < 0) {
                client_free(client);
                return false;
        }
#else
        if (!fr_rb_insert(clients->tree[client->ipaddr.prefix], client)) {
                client_free(client);
                return false;
        }
#endif
 
        /*
         *      @todo - do we want to do this for dynamic clients?
         */
        (void) talloc_steal(clients, client); /* reparent it */
 
        return true;
}
 
 
void client_delete(fr_client_list_t *clients, fr_client_t *client)
{
#ifdef WITH_TRIE
        fr_trie_t *trie;
#endif
 
        if (!client) return;
 
        if (!clients) clients = root_clients;
 
        fr_assert(client->ipaddr.prefix <= 128);
 
#ifdef WITH_TRIE
        trie = clients_trie(clients, &client->ipaddr, client->proto);
 
        /*
         *      Don't free the client.  The caller is responsible for that.
         */
        (void) fr_trie_remove_by_key(trie, &client->ipaddr.addr, client->ipaddr.prefix);
#else
 
        if (!clients->tree[client->ipaddr.prefix]) return;
 
        (void) fr_rb_delete(clients->tree[client->ipaddr.prefix], client);
#endif
}
 
fr_client_t *client_findbynumber(UNUSED const fr_client_list_t *clients, UNUSED int number)
{
        return NULL;
}
 
 
/*
 *      Find a client in the fr_client_tS list.
 */
fr_client_t *client_find(fr_client_list_t const *clients, fr_ipaddr_t const *ipaddr, int proto)
{
#ifdef WITH_TRIE
        fr_trie_t *trie;
#else
        int i, max;
        fr_client_t my_client, *client;
#endif
 
        if (!clients) clients = root_clients;
 
        if (!clients || !ipaddr) return NULL;
 
#ifdef WITH_TRIE
        trie = clients_trie(clients, ipaddr, proto);
 
        return fr_trie_lookup_by_key(trie, &ipaddr->addr, ipaddr->prefix);
#else
 
        if (proto == AF_INET) {
                max = 32;
        } else {
                max = 128;
        }
 
        if (max > ipaddr->prefix) max = ipaddr->prefix;
 
        my_client.proto = proto;
        for (i = max; i >= 0; i--) {
                if (!clients->tree[i]) continue;
 
                my_client.ipaddr = *ipaddr;
                fr_ipaddr_mask(&my_client.ipaddr, i);
                client = fr_rb_find(clients->tree[i], &my_client);
                if (client) {
                        return client;
                }
        }
 
        return NULL;
#endif
}
 
static fr_ipaddr_t cl_ipaddr;
static char const *cl_srcipaddr = NULL;
static char const *hs_proto = NULL;
 
static conf_parser_t limit_config[] = {
        { FR_CONF_OFFSET("max_connections", fr_client_t, limit.max_connections), .dflt = "16" },
 
        { FR_CONF_OFFSET("lifetime", fr_client_t, limit.lifetime), .dflt = "0" },
 
        { FR_CONF_OFFSET("idle_timeout", fr_client_t, limit.idle_timeout), .dflt = "30s" },
        CONF_PARSER_TERMINATOR
};
 
static const conf_parser_t client_config[] = {
        { FR_CONF_POINTER("ipaddr", FR_TYPE_COMBO_IP_PREFIX, 0, &cl_ipaddr) },
        { FR_CONF_POINTER("ipv4addr", FR_TYPE_IPV4_PREFIX, 0, &cl_ipaddr) },
        { FR_CONF_POINTER("ipv6addr", FR_TYPE_IPV6_PREFIX, 0, &cl_ipaddr) },
 
        { FR_CONF_POINTER("src_ipaddr", FR_TYPE_STRING, 0, &cl_srcipaddr) },
 
        { FR_CONF_OFFSET_FLAGS("secret", CONF_FLAG_SECRET, fr_client_t, secret) },
        { FR_CONF_OFFSET("shortname", fr_client_t, shortname) },
 
        { FR_CONF_OFFSET("nas_type", fr_client_t, nas_type) },
 
        { FR_CONF_OFFSET("track_connections", fr_client_t, use_connected) },
 
        { FR_CONF_OFFSET("require_message_authenticator", fr_client_t, message_authenticator) },
 
        { FR_CONF_OFFSET("dedup_authenticator", fr_client_t, dedup_authenticator) },
 
        { FR_CONF_OFFSET("response_window", fr_client_t, response_window) },
 
        { FR_CONF_POINTER("proto", FR_TYPE_STRING, 0, &hs_proto) },
        { FR_CONF_POINTER("limit", 0, CONF_FLAG_SUBSECTION, NULL), .subcs = (void const *) limit_config },
 
        CONF_PARSER_TERMINATOR
};
 
/** Create a list of clients from a client section
 *
 * Iterates over all client definitions in the specified section, adding them to a client list.
 */
#ifdef WITH_TLS
#define TLS_UNUSED
#else
#define TLS_UNUSED UNUSED
#endif
 
fr_client_list_t *client_list_parse_section(CONF_SECTION *section, int proto, TLS_UNUSED bool tls_required)
{
        bool            global = false;
        CONF_SECTION    *cs = NULL;
        fr_client_t     *c = NULL;
        fr_client_list_t        *clients = NULL;
        CONF_SECTION    *server_cs = NULL;
 
        /*
         *      Be forgiving.  If there's already a clients, return
         *      it.  Otherwise create a new one.
         */
        clients = cf_data_value(cf_data_find(section, fr_client_list_t, NULL));
        if (clients) return clients;
 
        /*
         *      Parent the client list from the section.
         */
        clients = client_list_init(section);
        if (!clients) return NULL;
 
        /*
         *      If the section is hung off the config root, this is
         *      the global client list, else it's virtual server
         *      specific client list.
         */
        if (cf_root(section) == section) global = true;
 
        if (strcmp("server", cf_section_name1(section)) == 0) server_cs = section;
 
        /*
         *      Iterate over all the clients in the section, adding
         *      them to the client list.
         */
        while ((cs = cf_section_find_next(section, cs, "client", CF_IDENT_ANY))) {
                /*
                 *      Check this before parsing the client.
                 */
                if (proto) {
                        CONF_PAIR *cp;
                        int client_proto = IPPROTO_UDP;
 
                        cp = cf_pair_find(cs, "proto");
                        if (cp) {
                                char const *value = cf_pair_value(cp);
 
                                if (!value) {
                                        cf_log_err(cs, "'proto' field must have a value");
                                        talloc_free(clients);
                                        return NULL;
                                }
 
                                if (strcmp(value, "udp") == 0) {
                                        /* do nothing */
 
                                } else if (strcmp(value, "tcp") == 0) {
                                        client_proto = IPPROTO_TCP;
#ifdef WITH_TLS
                                } else if (strcmp(value, "tls") == 0) {
                                        client_proto = IPPROTO_TCP;
#endif
                                } else if (strcmp(value, "*") == 0) {
                                        client_proto = IPPROTO_IP; /* fake for dual */
                                } else {
                                        cf_log_err(cs, "Unknown proto \"%s\".", value);
                                        talloc_free(clients);
                                        return NULL;
                                }
                        }
 
                        /*
                         *      We don't have "proto = *", so the
                         *      protocol MUST match what the caller
                         *      asked for.  Otherwise, we ignore the
                         *      client.
                         */
                        if ((client_proto != IPPROTO_IP) && (proto != client_proto)) continue;
                }
 
 
                c = client_afrom_cs(cs, cs, server_cs, 0);
                if (!c) {
                error:
                        client_free(c);
                        talloc_free(clients);
                        return NULL;
                }
 
                /*
                 *      TCP sockets are always connected.
                 */
                c->use_connected |= (c->proto == IPPROTO_TCP);
 
#ifdef WITH_TLS
                /*
                 *      TLS clients CANNOT use non-TLS listeners.
                 *      non-TLS clients CANNOT use TLS listeners.
                 */
                if (tls_required != c->tls_required) {
                        cf_log_err(cs, "Client does not have the same TLS configuration as the listener");
                        goto error;
                }
#endif
 
                if (!client_add(clients, c)) {
                        cf_log_err(cs, "Failed to add client %s", cf_section_name2(cs));
                        goto error;
                }
 
        }
 
        /*
         *      Associate the clients structure with the section.
         */
        if (!cf_data_add(section, clients, NULL, false)) {
                cf_log_err(section, "Failed to associate clients with section %s", cf_section_name1(section));
                talloc_free(clients);
                return NULL;
        }
 
        /*
         *      Replace the global list of clients with the new one.
         *      The old one is still referenced from the original
         *      configuration, and will be freed when that is freed.
         */
        if (global) root_clients = clients;
 
        return clients;
}
 
/** Create a client CONF_SECTION using a mapping section to map values from a result set to client attributes
 *
 * If we hit a CONF_SECTION we recurse and process its CONF_PAIRS too.
 *
 * @note Caller should free CONF_SECTION passed in as out, on error.
 *       Contents of that section will be in an undefined state.
 *
 * @param[in,out] out Section to perform mapping on. Either the root of the client config, or a parent section
 *      (when this function is called recursively).
 *      Should be alloced with cf_section_alloc, or if there's a separate template section, the
 *      result of calling cf_section_dup on that section.
 * @param[in] map section.
 * @param[in] func to call to retrieve CONF_PAIR values. Must return a talloced buffer containing the value.
 * @param[in] data to pass to func, usually a result pointer.
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
int client_map_section(CONF_SECTION *out, CONF_SECTION const *map, client_value_cb_t func, void *data)
{
        CONF_ITEM const *ci;
 
        for (ci = cf_item_next(map, NULL);
             ci != NULL;
             ci = cf_item_next(map, ci)) {
                CONF_PAIR const *cp;
                CONF_PAIR *old;
                char *value;
                char const *attr;
 
                /*
                 *      Recursively process map subsection
                 */
                if (cf_item_is_section(ci)) {
                        CONF_SECTION *cs, *cc;
 
                        cs = cf_item_to_section(ci);
                        /*
                         *      Use pre-existing section or alloc a new one
                         */
                        cc = cf_section_find(out, cf_section_name1(cs), cf_section_name2(cs));
                        if (!cc) {
                                cc = cf_section_alloc(out, out, cf_section_name1(cs), cf_section_name2(cs));
                                if (!cc) return -1;
                        }
 
                        if (client_map_section(cc, cs, func, data) < 0) return -1;
                        continue;
                }
 
                cp = cf_item_to_pair(ci);
                attr = cf_pair_attr(cp);
 
                /*
                 *      The callback can return 0 (success) and not provide a value
                 *      in which case we skip the mapping pair.
                 *
                 *      Or return -1 in which case we error out.
                 */
                if (func(&value, cp, data) < 0) {
                        cf_log_err(out, "Failed performing mapping \"%s\" = \"%s\"", attr, cf_pair_value(cp));
                        return -1;
                }
                if (!value) continue;
 
                /*
                 *      Replace an existing CONF_PAIR
                 */
                old = cf_pair_find(out, attr);
                if (old) {
                        cf_pair_replace(out, old, value);
                        talloc_free(value);
                        continue;
                }
 
                /*
                 *      ...or add a new CONF_PAIR
                 */
                cp = cf_pair_alloc(out, attr, value, T_OP_SET, T_BARE_WORD, T_SINGLE_QUOTED_STRING);
                if (!cp) {
                        cf_log_err(out, "Failed allocing pair \"%s\" = \"%s\"", attr, value);
                        talloc_free(value);
                        return -1;
                }
                talloc_free(value);
                cf_item_add(out, cf_pair_to_item(cp));
        }
 
        return 0;
}
 
/** Allocate a new client from a config section
 *
 * @param ctx to allocate new clients in.
 * @param cs to process as a client.
 * @param server_cs The virtual server that this client belongs to.
 * @param extra 0                 allocate sizeof(fr_client_t) bytes
 *              >sizeof(client_t) number of bytes to allocate
 * @return new fr_client_t struct.
 */
fr_client_t *client_afrom_cs(TALLOC_CTX *ctx, CONF_SECTION *cs, CONF_SECTION *server_cs, size_t extra)
{
        fr_client_t     *c;
        char const      *name2;
        CONF_PAIR       *cp;
 
        name2 = cf_section_name2(cs);
        if (!name2) {
                cf_log_err(cs, "Missing client name");
                return NULL;
        }
 
        /*
         *      The size is fine.. Let's create the buffer
         */
        if (!extra) {
                c = talloc_zero(ctx, fr_client_t);
                if (!c) return NULL;
        } else {
                fr_assert(extra > sizeof(fr_client_t));
 
                c = (fr_client_t *) talloc_zero_array(ctx, uint8_t, extra);
                if (!c) return NULL;
 
                talloc_set_name_const(c, "fr_client_t");
        }
 
        c->cs = cs;
 
        memset(&cl_ipaddr, 0, sizeof(cl_ipaddr));
        if (cf_section_rules_push(cs, client_config) < 0) return NULL;
 
        if (cf_section_parse(c, c, cs) < 0) {
                cf_log_err(cs, "Error parsing client section");
        error:
                client_free(c);
                hs_proto = NULL;
                cl_srcipaddr = NULL;
                return NULL;
        }
 
        /*
         *      Allow for binary secrets.
         */
        cp = cf_pair_find(cs, "secret");
        if (cp && (cf_pair_operator(cp) == T_BARE_WORD)) {
                char const *value;
 
                value = cf_pair_value(cp);
                if ((value[0] == '0') && (value[1] == 'x')) {
                        size_t bin_len, hex_len, converted;
                        uint8_t *bin;
 
                        /*
                         *      '0x...' plus trailing NUL.
                         */
                        hex_len = talloc_array_length(value) - 3;
                        bin_len = (hex_len / 2) + 1;
                        MEM(bin = talloc_array(c, uint8_t, bin_len));
                        converted = fr_base16_decode(NULL,
                                               &FR_DBUFF_TMP(bin, bin_len),
                                               &FR_SBUFF_IN(value + 2, hex_len), false);
                        if (converted < (bin_len - 1)) {
                                cf_log_err(cs, "Invalid hex string in shared secret");
                                goto error;
                        }
 
                        talloc_const_free(c->secret);
                        c->secret = (char const *) bin;
                }
        }
 
        /*
         *      Find the virtual server for this client.
         */
        if (c->server) {
                if (server_cs) {
                        cf_log_err(cs, "Clients inside of a 'server' section cannot point to a server");
                        goto error;
                }
 
                c->server_cs = virtual_server_find(c->server);
                if (!c->server_cs) {
                        cf_log_err(cs, "Failed to find virtual server %s", c->server);
                        goto error;
                }
 
        } else if (server_cs) {
                c->server = cf_section_name2(server_cs);
                c->server_cs = server_cs;
 
        } /* else don't set c->server or c->server_cs, we will use listener->server */
 
        /*
         *      Newer style client definitions with either ipaddr or ipaddr6
         *      config items.
         */
        if (cf_pair_find(cs, "ipaddr") || cf_pair_find(cs, "ipv4addr") || cf_pair_find(cs, "ipv6addr")) {
                char buffer[128];
 
                /*
                 *      Sets ipv4/ipv6 address and prefix.
                 */
                c->ipaddr = cl_ipaddr;
 
                /*
                 *      Set the long name to be the result of a reverse lookup on the IP address.
                 */
                fr_inet_ntoh(&c->ipaddr, buffer, sizeof(buffer));
                c->longname = talloc_typed_strdup(c, buffer);
 
                /*
                 *      Set the short name to the name2.
                 */
                if (!c->shortname) c->shortname = talloc_typed_strdup(c, name2);
        /*
         *      No "ipaddr" or "ipv6addr", use old-style "client <ipaddr> {" syntax.
         */
        } else {
                cf_log_err(cs, "No 'ipaddr' or 'ipv4addr' or 'ipv6addr' configuration "
                              "directive found in client %s", name2);
                goto error;
        }
 
        c->proto = IPPROTO_UDP;
        if (hs_proto) {
                if (strcmp(hs_proto, "udp") == 0) {
                        hs_proto = NULL;
 
                } else if (strcmp(hs_proto, "tcp") == 0) {
                        hs_proto = NULL;
                        c->proto = IPPROTO_TCP;
#ifdef WITH_TLS
                } else if (strcmp(hs_proto, "tls") == 0) {
                        hs_proto = NULL;
                        c->proto = IPPROTO_TCP;
                        c->tls_required = true;
 
#endif
                } else if (strcmp(hs_proto, "*") == 0) {
                        hs_proto = NULL;
                        c->proto = IPPROTO_IP; /* fake for dual */
                } else {
                        cf_log_err(cs, "Unknown proto \"%s\".", hs_proto);
                        goto error;
                }
        }
 
        /*
         *      If a src_ipaddr is specified, when we send the return packet
         *      we will use this address instead of the src from the
         *      request.
         */
        if (cl_srcipaddr) {
                switch (c->ipaddr.af) {
                case AF_INET:
                        if (fr_inet_pton4(&c->src_ipaddr, cl_srcipaddr, -1, true, false, true) < 0) {
                                cf_log_perr(cs, "Failed parsing src_ipaddr");
                                goto error;
                        }
                        break;
 
                case AF_INET6:
                        if (fr_inet_pton6(&c->src_ipaddr, cl_srcipaddr, -1, true, false, true) < 0) {
                                cf_log_perr(cs, "Failed parsing src_ipaddr");
                                goto error;
                        }
                        break;
                default:
                        cf_log_err(cs, "ipaddr was not defined");
                        goto error;
                }
                cl_srcipaddr = NULL;
        } else {
                c->src_ipaddr.af = c->ipaddr.af; /* leave the rest as IFADDR_ANY */
        }
 
        /*
         *      A response_window of zero is OK, and means that it's
         *      ignored by the rest of the server timers.
         */
        if (fr_time_delta_ispos(c->response_window)) {
                FR_TIME_DELTA_BOUND_CHECK("response_window", c->response_window, >=, fr_time_delta_from_usec(1000));
                FR_TIME_DELTA_BOUND_CHECK("response_window", c->response_window, <=, fr_time_delta_from_sec(60));
                FR_TIME_DELTA_BOUND_CHECK("response_window", c->response_window, <=, main_config->max_request_time);
        }
 
#ifdef WITH_TLS
        /*
         *      If the client is TLS only, the secret can be
         *      omitted.  When omitted, it's hard-coded to
         *      "radsec".  See RFC 6614.
         */
        if (c->tls_required) {
                c->secret = talloc_typed_strdup(cs, "radsec");
        }
#endif
 
        if ((c->proto == IPPROTO_TCP) || (c->proto == IPPROTO_IP)) {
                if (fr_time_delta_ispos(c->limit.idle_timeout) && fr_time_delta_lt(c->limit.idle_timeout, fr_time_delta_from_sec(5)))
                        c->limit.idle_timeout = fr_time_delta_from_sec(5);
                if (fr_time_delta_ispos(c->limit.lifetime) && (fr_time_delta_lt(c->limit.lifetime, fr_time_delta_from_sec(5))))
                        c->limit.lifetime = fr_time_delta_from_sec(5);
                if (fr_time_delta_ispos(c->limit.lifetime) && (fr_time_delta_lt(c->limit.idle_timeout, c->limit.lifetime)))
                        c->limit.idle_timeout = fr_time_delta_wrap(0);
        }
 
        return c;
}
 
/** Create a new client, consuming all attributes in the control list of the request
 *
 * @param ctx the talloc context
 * @param request containing the client attributes.
 * @return
 *      - New client on success.
 *      - NULL on error.
 */
fr_client_t *client_afrom_request(TALLOC_CTX *ctx, request_t *request)
{
        static int      cnt;
        CONF_SECTION    *cs;
        char            src_buf[128], buffer[256];
        fr_client_t     *c;
 
        if (!request) return NULL;
 
        fr_value_box_print(&FR_SBUFF_OUT(src_buf, sizeof(src_buf)), fr_box_ipaddr(request->packet->socket.inet.src_ipaddr), NULL);
 
        snprintf(buffer, sizeof(buffer), "dynamic_%i_%s", cnt++, src_buf);
 
        cs = cf_section_alloc(ctx, NULL, "client", buffer);
 
        RDEBUG2("Converting &control.FreeRADIUS-Client-* to client {...} section");
        RINDENT();
 
        fr_pair_list_foreach(&request->control_pairs, vp) {
                CONF_PAIR       *cp = NULL;
                char const      *value;
                char const      *attr;
 
                if (!fr_dict_attr_is_top_level(vp->da)) continue;
 
                switch (vp->da->attr) {
                case FR_FREERADIUS_CLIENT_IP_ADDRESS:
                        attr = "ipv4addr";
                        value = fr_inet_ntop(buffer, sizeof(buffer), &vp->vp_ip);
                        break;
 
                case FR_FREERADIUS_CLIENT_IP_PREFIX:
                        attr = "ipv4addr";
                        value = fr_inet_ntop_prefix(buffer, sizeof(buffer), &vp->vp_ip);
                        break;
 
                case FR_FREERADIUS_CLIENT_IPV6_ADDRESS:
                        attr = "ipv6addr";
                        value = fr_inet_ntop(buffer, sizeof(buffer), &vp->vp_ip);
                        break;
 
                case FR_FREERADIUS_CLIENT_IPV6_PREFIX:
                        attr = "ipv6addr";
                        value = fr_inet_ntop_prefix(buffer, sizeof(buffer), &vp->vp_ip);
                        break;
 
                case FR_FREERADIUS_CLIENT_SECRET:
                        attr = "secret";
                        value = vp->vp_strvalue;
                        break;
 
                case FR_FREERADIUS_CLIENT_NAS_TYPE:
                        attr = "nas_type";
                        value = vp->vp_strvalue;
                        break;
 
                case FR_FREERADIUS_CLIENT_SHORTNAME:
                        attr = "shortname";
                        value = vp->vp_strvalue;
                        break;
 
                case FR_FREERADIUS_CLIENT_SRC_IP_ADDRESS:
                        attr = "src_ipaddr";
                        value = fr_inet_ntop(buffer, sizeof(buffer), &vp->vp_ip);
                        break;
 
                case FR_FREERADIUS_CLIENT_REQUIRE_MA:
                        attr = "require_message_authenticator";
                        if (vp->vp_bool) {
                                value = "true";
                        } else {
                                value = "false";
                        }
                        break;
 
                case FR_FREERADIUS_CLIENT_TRACK_CONNECTIONS:
                        attr = "track_connections";
                        if (vp->vp_bool) {
                                value = "true";
                        } else {
                                value = "false";
                        }
                        break;
 
                default:
                        RERROR("Ignoring attribute %s", vp->da->name);
                        continue;
                }
 
                cp = cf_pair_alloc(cs, attr, value, T_OP_SET, T_BARE_WORD, T_BARE_WORD);
                if (!cp) {
                        RERROR("Error creating equivalent conf pair for %s", vp->da->name);
                        goto error;
                }
 
                RDEBUG2("%s = %s", cf_pair_attr(cp), cf_pair_value(cp));
        }
 
        REXDENT();
 
        /*
         *      @todo - allow for setting a DIFFERENT virtual server,
         *      src IP, protocol, etc.  This should all be in TLVs..
         */
        c = client_afrom_cs(cs, cs, unlang_call_current(request), 0);
        if (!c) {
        error:
                talloc_free(cs);
                return NULL;
        }
 
        return c;
}
 
/** Read a single client from a file
 *
 * This function supports asynchronous runtime loading of clients.
 *
 * @param[in] filename          To read clients from.
 * @param[in] server_cs         of virtual server clients should be added to.
 * @param[in] check_dns         Check reverse lookup of IP address matches filename.
 * @return
 *      - The new client on success.
 *      - NULL on failure.
 */
fr_client_t *client_read(char const *filename, CONF_SECTION *server_cs, bool check_dns)
{
        char const      *p;
        fr_client_t     *c;
        CONF_SECTION    *cs;
        char buffer[256];
 
        if (!filename) return NULL;
 
        cs = cf_section_alloc(NULL, NULL, "main", NULL);
        if (!cs) return NULL;
 
        if ((cf_file_read(cs, filename) < 0) || (cf_section_pass2(cs) < 0)) {
                talloc_free(cs);
                return NULL;
        }
 
        cs = cf_section_find(cs, "client", CF_IDENT_ANY);
        if (!cs) {
                ERROR("No \"client\" section found in client file");
                return NULL;
        }
 
        c = client_afrom_cs(cs, cs, server_cs, 0);
        if (!c) return NULL;
        talloc_steal(cs, c);
 
        p = strrchr(filename, FR_DIR_SEP);
        if (p) {
                p++;
        } else {
                p = filename;
        }
 
        if (!check_dns) return c;
 
        /*
         *      Additional validations
         */
        fr_inet_ntoh(&c->ipaddr, buffer, sizeof(buffer));
        if (strcmp(p, buffer) != 0) {
                ERROR("Invalid client definition in %s: IP address %s does not match name %s", filename, buffer, p);
                client_free(c);
                return NULL;
        }
 
        return c;
}
 
/** Search up a list of requests trying to locate one which has a client
 *
 */
fr_client_t *client_from_request(request_t *request)
{
        fr_client_t *client;
        request_t *parent = request;
 
        do {
                client = parent->client;
        } while (!client && (parent = request->parent));
 
        return client;
}