radius_server.c

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/*
 * RADIUS authentication server
 * Copyright (c) 2005-2009, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"
#include <net/if.h>

#include "common.h"
#include "radius.h"
#include "eloop.h"
#include "eap_server/eap.h"
#include "radius_server.h"

#define RADIUS_SESSION_TIMEOUT 60

#define RADIUS_MAX_SESSION 100

#define RADIUS_MAX_MSG_LEN 3000

static struct eapol_callbacks radius_server_eapol_cb;

struct radius_client;
struct radius_server_data;

struct radius_server_counters {
        u32 access_requests;
        u32 invalid_requests;
        u32 dup_access_requests;
        u32 access_accepts;
        u32 access_rejects;
        u32 access_challenges;
        u32 malformed_access_requests;
        u32 bad_authenticators;
        u32 packets_dropped;
        u32 unknown_types;
};

struct radius_session {
        struct radius_session *next;
        struct radius_client *client;
        struct radius_server_data *server;
        unsigned int sess_id;
        struct eap_sm *eap;
        struct eap_eapol_interface *eap_if;

        struct radius_msg *last_msg;
        char *last_from_addr;
        int last_from_port;
        struct sockaddr_storage last_from;
        socklen_t last_fromlen;
        u8 last_identifier;
        struct radius_msg *last_reply;
        u8 last_authenticator[16];
};

struct radius_client {
        struct radius_client *next;
        struct in_addr addr;
        struct in_addr mask;
#ifdef CONFIG_IPV6
        struct in6_addr addr6;
        struct in6_addr mask6;
#endif /* CONFIG_IPV6 */
        char *shared_secret;
        int shared_secret_len;
        struct radius_session *sessions;
        struct radius_server_counters counters;
};

struct radius_server_data {
        int auth_sock;

        struct radius_client *clients;

        unsigned int next_sess_id;

        void *conf_ctx;

        int num_sess;

        void *eap_sim_db_priv;

        void *ssl_ctx;

        u8 *pac_opaque_encr_key;

        u8 *eap_fast_a_id;

        size_t eap_fast_a_id_len;

        char *eap_fast_a_id_info;

        int eap_fast_prov;

        int pac_key_lifetime;

        int pac_key_refresh_time;

        int eap_sim_aka_result_ind;

        int tnc;

        struct wps_context *wps;

        int ipv6;

        struct os_time start_time;

        struct radius_server_counters counters;

        int (*get_eap_user)(void *ctx, const u8 *identity, size_t identity_len,
                            int phase2, struct eap_user *user);

        char *eap_req_id_text;

        size_t eap_req_id_text_len;

        /*
         * msg_ctx - Context data for wpa_msg() calls
         */
        void *msg_ctx;
};


extern int wpa_debug_level;

#define RADIUS_DEBUG(args...) \
wpa_printf(MSG_DEBUG, "RADIUS SRV: " args)
#define RADIUS_ERROR(args...) \
wpa_printf(MSG_ERROR, "RADIUS SRV: " args)
#define RADIUS_DUMP(args...) \
wpa_hexdump(MSG_MSGDUMP, "RADIUS SRV: " args)
#define RADIUS_DUMP_ASCII(args...) \
wpa_hexdump_ascii(MSG_MSGDUMP, "RADIUS SRV: " args)


static void radius_server_session_timeout(void *eloop_ctx, void *timeout_ctx);
static void radius_server_session_remove_timeout(void *eloop_ctx,
                                                 void *timeout_ctx);


static struct radius_client *
radius_server_get_client(struct radius_server_data *data, struct in_addr *addr,
                         int ipv6)
{
        struct radius_client *client = data->clients;

        while (client) {
#ifdef CONFIG_IPV6
                if (ipv6) {
                        struct in6_addr *addr6;
                        int i;

                        addr6 = (struct in6_addr *) addr;
                        for (i = 0; i < 16; i++) {
                                if ((addr6->s6_addr[i] &
                                     client->mask6.s6_addr[i]) !=
                                    (client->addr6.s6_addr[i] &
                                     client->mask6.s6_addr[i])) {
                                        i = 17;
                                        break;
                                }
                        }
                        if (i == 16) {
                                break;
                        }
                }
#endif /* CONFIG_IPV6 */
                if (!ipv6 && (client->addr.s_addr & client->mask.s_addr) ==
                    (addr->s_addr & client->mask.s_addr)) {
                        break;
                }

                client = client->next;
        }

        return client;
}


static struct radius_session *
radius_server_get_session(struct radius_client *client, unsigned int sess_id)
{
        struct radius_session *sess = client->sessions;

        while (sess) {
                if (sess->sess_id == sess_id) {
                        break;
                }
                sess = sess->next;
        }

        return sess;
}


static void radius_server_session_free(struct radius_server_data *data,
                                       struct radius_session *sess)
{
        eloop_cancel_timeout(radius_server_session_timeout, data, sess);
        eloop_cancel_timeout(radius_server_session_remove_timeout, data, sess);
        eap_server_sm_deinit(sess->eap);
        radius_msg_free(sess->last_msg);
        os_free(sess->last_from_addr);
        radius_msg_free(sess->last_reply);
        os_free(sess);
        data->num_sess--;
}


static void radius_server_session_remove(struct radius_server_data *data,
                                         struct radius_session *sess)
{
        struct radius_client *client = sess->client;
        struct radius_session *session, *prev;

        eloop_cancel_timeout(radius_server_session_remove_timeout, data, sess);

        prev = NULL;
        session = client->sessions;
        while (session) {
                if (session == sess) {
                        if (prev == NULL) {
                                client->sessions = sess->next;
                        } else {
                                prev->next = sess->next;
                        }
                        radius_server_session_free(data, sess);
                        break;
                }
                prev = session;
                session = session->next;
        }
}


static void radius_server_session_remove_timeout(void *eloop_ctx,
                                                 void *timeout_ctx)
{
        struct radius_server_data *data = eloop_ctx;
        struct radius_session *sess = timeout_ctx;
        RADIUS_DEBUG("Removing completed session 0x%x", sess->sess_id);
        radius_server_session_remove(data, sess);
}


static void radius_server_session_timeout(void *eloop_ctx, void *timeout_ctx)
{
        struct radius_server_data *data = eloop_ctx;
        struct radius_session *sess = timeout_ctx;

        RADIUS_DEBUG("Timing out authentication session 0x%x", sess->sess_id);
        radius_server_session_remove(data, sess);
}


static struct radius_session *
radius_server_new_session(struct radius_server_data *data,
                          struct radius_client *client)
{
        struct radius_session *sess;

        if (data->num_sess >= RADIUS_MAX_SESSION) {
                RADIUS_DEBUG("Maximum number of existing session - no room "
                             "for a new session");
                return NULL;
        }

        sess = os_zalloc(sizeof(*sess));
        if (sess == NULL)
                return NULL;

        sess->server = data;
        sess->client = client;
        sess->sess_id = data->next_sess_id++;
        sess->next = client->sessions;
        client->sessions = sess;
        eloop_register_timeout(RADIUS_SESSION_TIMEOUT, 0,
                               radius_server_session_timeout, data, sess);
        data->num_sess++;
        return sess;
}


static struct radius_session *
radius_server_get_new_session(struct radius_server_data *data,
                              struct radius_client *client,
                              struct radius_msg *msg)
{
        u8 *user;
        size_t user_len;
        int res;
        struct radius_session *sess;
        struct eap_config eap_conf;

        RADIUS_DEBUG("Creating a new session");

        user = os_malloc(256);
        if (user == NULL) {
                return NULL;
        }
        res = radius_msg_get_attr(msg, RADIUS_ATTR_USER_NAME, user, 256);
        if (res < 0 || res > 256) {
                RADIUS_DEBUG("Could not get User-Name");
                os_free(user);
                return NULL;
        }
        user_len = res;
        RADIUS_DUMP_ASCII("User-Name", user, user_len);

        res = data->get_eap_user(data->conf_ctx, user, user_len, 0, NULL);
        os_free(user);

        if (res == 0) {
                RADIUS_DEBUG("Matching user entry found");
                sess = radius_server_new_session(data, client);
                if (sess == NULL) {
                        RADIUS_DEBUG("Failed to create a new session");
                        return NULL;
                }
        } else {
                RADIUS_DEBUG("User-Name not found from user database");
                return NULL;
        }

        os_memset(&eap_conf, 0, sizeof(eap_conf));
        eap_conf.ssl_ctx = data->ssl_ctx;
        eap_conf.msg_ctx = data->msg_ctx;
        eap_conf.eap_sim_db_priv = data->eap_sim_db_priv;
        eap_conf.backend_auth = TRUE;
        eap_conf.eap_server = 1;
        eap_conf.pac_opaque_encr_key = data->pac_opaque_encr_key;
        eap_conf.eap_fast_a_id = data->eap_fast_a_id;
        eap_conf.eap_fast_a_id_len = data->eap_fast_a_id_len;
        eap_conf.eap_fast_a_id_info = data->eap_fast_a_id_info;
        eap_conf.eap_fast_prov = data->eap_fast_prov;
        eap_conf.pac_key_lifetime = data->pac_key_lifetime;
        eap_conf.pac_key_refresh_time = data->pac_key_refresh_time;
        eap_conf.eap_sim_aka_result_ind = data->eap_sim_aka_result_ind;
        eap_conf.tnc = data->tnc;
        eap_conf.wps = data->wps;
        sess->eap = eap_server_sm_init(sess, &radius_server_eapol_cb,
                                       &eap_conf);
        if (sess->eap == NULL) {
                RADIUS_DEBUG("Failed to initialize EAP state machine for the "
                             "new session");
                radius_server_session_free(data, sess);
                return NULL;
        }
        sess->eap_if = eap_get_interface(sess->eap);
        sess->eap_if->eapRestart = TRUE;
        sess->eap_if->portEnabled = TRUE;

        RADIUS_DEBUG("New session 0x%x initialized", sess->sess_id);

        return sess;
}


static struct radius_msg *
radius_server_encapsulate_eap(struct radius_server_data *data,
                              struct radius_client *client,
                              struct radius_session *sess,
                              struct radius_msg *request)
{
        struct radius_msg *msg;
        int code;
        unsigned int sess_id;
        struct radius_hdr *hdr = radius_msg_get_hdr(request);

        if (sess->eap_if->eapFail) {
                sess->eap_if->eapFail = FALSE;
                code = RADIUS_CODE_ACCESS_REJECT;
        } else if (sess->eap_if->eapSuccess) {
                sess->eap_if->eapSuccess = FALSE;
                code = RADIUS_CODE_ACCESS_ACCEPT;
        } else {
                sess->eap_if->eapReq = FALSE;
                code = RADIUS_CODE_ACCESS_CHALLENGE;
        }

        msg = radius_msg_new(code, hdr->identifier);
        if (msg == NULL) {
                RADIUS_DEBUG("Failed to allocate reply message");
                return NULL;
        }

        sess_id = htonl(sess->sess_id);
        if (code == RADIUS_CODE_ACCESS_CHALLENGE &&
            !radius_msg_add_attr(msg, RADIUS_ATTR_STATE,
                                 (u8 *) &sess_id, sizeof(sess_id))) {
                RADIUS_DEBUG("Failed to add State attribute");
        }

        if (sess->eap_if->eapReqData &&
            !radius_msg_add_eap(msg, wpabuf_head(sess->eap_if->eapReqData),
                                wpabuf_len(sess->eap_if->eapReqData))) {
                RADIUS_DEBUG("Failed to add EAP-Message attribute");
        }

        if (code == RADIUS_CODE_ACCESS_ACCEPT && sess->eap_if->eapKeyData) {
                int len;
                if (sess->eap_if->eapKeyDataLen > 64) {
                        len = 32;
                } else {
                        len = sess->eap_if->eapKeyDataLen / 2;
                }
                if (!radius_msg_add_mppe_keys(msg, hdr->authenticator,
                                              (u8 *) client->shared_secret,
                                              client->shared_secret_len,
                                              sess->eap_if->eapKeyData + len,
                                              len, sess->eap_if->eapKeyData,
                                              len)) {
                        RADIUS_DEBUG("Failed to add MPPE key attributes");
                }
        }

        if (radius_msg_copy_attr(msg, request, RADIUS_ATTR_PROXY_STATE) < 0) {
                RADIUS_DEBUG("Failed to copy Proxy-State attribute(s)");
                radius_msg_free(msg);
                return NULL;
        }

        if (radius_msg_finish_srv(msg, (u8 *) client->shared_secret,
                                  client->shared_secret_len,
                                  hdr->authenticator) < 0) {
                RADIUS_DEBUG("Failed to add Message-Authenticator attribute");
        }

        return msg;
}


static int radius_server_reject(struct radius_server_data *data,
                                struct radius_client *client,
                                struct radius_msg *request,
                                struct sockaddr *from, socklen_t fromlen,
                                const char *from_addr, int from_port)
{
        struct radius_msg *msg;
        int ret = 0;
        struct eap_hdr eapfail;
        struct wpabuf *buf;
        struct radius_hdr *hdr = radius_msg_get_hdr(request);

        RADIUS_DEBUG("Reject invalid request from %s:%d",
                     from_addr, from_port);

        msg = radius_msg_new(RADIUS_CODE_ACCESS_REJECT, hdr->identifier);
        if (msg == NULL) {
                return -1;
        }

        os_memset(&eapfail, 0, sizeof(eapfail));
        eapfail.code = EAP_CODE_FAILURE;
        eapfail.identifier = 0;
        eapfail.length = host_to_be16(sizeof(eapfail));

        if (!radius_msg_add_eap(msg, (u8 *) &eapfail, sizeof(eapfail))) {
                RADIUS_DEBUG("Failed to add EAP-Message attribute");
        }

        if (radius_msg_copy_attr(msg, request, RADIUS_ATTR_PROXY_STATE) < 0) {
                RADIUS_DEBUG("Failed to copy Proxy-State attribute(s)");
                radius_msg_free(msg);
                return -1;
        }

        if (radius_msg_finish_srv(msg, (u8 *) client->shared_secret,
                                  client->shared_secret_len,
                                  hdr->authenticator) <
            0) {
                RADIUS_DEBUG("Failed to add Message-Authenticator attribute");
        }

        if (wpa_debug_level <= MSG_MSGDUMP) {
                radius_msg_dump(msg);
        }

        data->counters.access_rejects++;
        client->counters.access_rejects++;
        buf = radius_msg_get_buf(msg);
        if (sendto(data->auth_sock, wpabuf_head(buf), wpabuf_len(buf), 0,
                   (struct sockaddr *) from, sizeof(*from)) < 0) {
                perror("sendto[RADIUS SRV]");
                ret = -1;
        }

        radius_msg_free(msg);

        return ret;
}


static int radius_server_request(struct radius_server_data *data,
                                 struct radius_msg *msg,
                                 struct sockaddr *from, socklen_t fromlen,
                                 struct radius_client *client,
                                 const char *from_addr, int from_port,
                                 struct radius_session *force_sess)
{
        u8 *eap = NULL;
        size_t eap_len;
        int res, state_included = 0;
        u8 statebuf[4];
        unsigned int state;
        struct radius_session *sess;
        struct radius_msg *reply;
        int is_complete = 0;

        if (force_sess)
                sess = force_sess;
        else {
                res = radius_msg_get_attr(msg, RADIUS_ATTR_STATE, statebuf,
                                          sizeof(statebuf));
                state_included = res >= 0;
                if (res == sizeof(statebuf)) {
                        state = WPA_GET_BE32(statebuf);
                        sess = radius_server_get_session(client, state);
                } else {
                        sess = NULL;
                }
        }

        if (sess) {
                RADIUS_DEBUG("Request for session 0x%x", sess->sess_id);
        } else if (state_included) {
                RADIUS_DEBUG("State attribute included but no session found");
                radius_server_reject(data, client, msg, from, fromlen,
                                     from_addr, from_port);
                return -1;
        } else {
                sess = radius_server_get_new_session(data, client, msg);
                if (sess == NULL) {
                        RADIUS_DEBUG("Could not create a new session");
                        radius_server_reject(data, client, msg, from, fromlen,
                                             from_addr, from_port);
                        return -1;
                }
        }

        if (sess->last_from_port == from_port &&
            sess->last_identifier == radius_msg_get_hdr(msg)->identifier &&
            os_memcmp(sess->last_authenticator,
                      radius_msg_get_hdr(msg)->authenticator, 16) == 0) {
                RADIUS_DEBUG("Duplicate message from %s", from_addr);
                data->counters.dup_access_requests++;
                client->counters.dup_access_requests++;

                if (sess->last_reply) {
                        struct wpabuf *buf;
                        buf = radius_msg_get_buf(sess->last_reply);
                        res = sendto(data->auth_sock, wpabuf_head(buf),
                                     wpabuf_len(buf), 0,
                                     (struct sockaddr *) from, fromlen);
                        if (res < 0) {
                                perror("sendto[RADIUS SRV]");
                        }
                        return 0;
                }

                RADIUS_DEBUG("No previous reply available for duplicate "
                             "message");
                return -1;
        }
                      
        eap = radius_msg_get_eap(msg, &eap_len);
        if (eap == NULL) {
                RADIUS_DEBUG("No EAP-Message in RADIUS packet from %s",
                             from_addr);
                data->counters.packets_dropped++;
                client->counters.packets_dropped++;
                return -1;
        }

        RADIUS_DUMP("Received EAP data", eap, eap_len);

        /* FIX: if Code is Request, Success, or Failure, send Access-Reject;
         * RFC3579 Sect. 2.6.2.
         * Include EAP-Response/Nak with no preferred method if
         * code == request.
         * If code is not 1-4, discard the packet silently.
         * Or is this already done by the EAP state machine? */

        wpabuf_free(sess->eap_if->eapRespData);
        sess->eap_if->eapRespData = wpabuf_alloc_ext_data(eap, eap_len);
        if (sess->eap_if->eapRespData == NULL)
                os_free(eap);
        eap = NULL;
        sess->eap_if->eapResp = TRUE;
        eap_server_sm_step(sess->eap);

        if ((sess->eap_if->eapReq || sess->eap_if->eapSuccess ||
             sess->eap_if->eapFail) && sess->eap_if->eapReqData) {
                RADIUS_DUMP("EAP data from the state machine",
                            wpabuf_head(sess->eap_if->eapReqData),
                            wpabuf_len(sess->eap_if->eapReqData));
        } else if (sess->eap_if->eapFail) {
                RADIUS_DEBUG("No EAP data from the state machine, but eapFail "
                             "set");
        } else if (eap_sm_method_pending(sess->eap)) {
                radius_msg_free(sess->last_msg);
                sess->last_msg = msg;
                sess->last_from_port = from_port;
                os_free(sess->last_from_addr);
                sess->last_from_addr = os_strdup(from_addr);
                sess->last_fromlen = fromlen;
                os_memcpy(&sess->last_from, from, fromlen);
                return -2;
        } else {
                RADIUS_DEBUG("No EAP data from the state machine - ignore this"
                             " Access-Request silently (assuming it was a "
                             "duplicate)");
                data->counters.packets_dropped++;
                client->counters.packets_dropped++;
                return -1;
        }

        if (sess->eap_if->eapSuccess || sess->eap_if->eapFail)
                is_complete = 1;

        reply = radius_server_encapsulate_eap(data, client, sess, msg);

        if (reply) {
                struct wpabuf *buf;
                struct radius_hdr *hdr;

                RADIUS_DEBUG("Reply to %s:%d", from_addr, from_port);
                if (wpa_debug_level <= MSG_MSGDUMP) {
                        radius_msg_dump(reply);
                }

                switch (radius_msg_get_hdr(reply)->code) {
                case RADIUS_CODE_ACCESS_ACCEPT:
                        data->counters.access_accepts++;
                        client->counters.access_accepts++;
                        break;
                case RADIUS_CODE_ACCESS_REJECT:
                        data->counters.access_rejects++;
                        client->counters.access_rejects++;
                        break;
                case RADIUS_CODE_ACCESS_CHALLENGE:
                        data->counters.access_challenges++;
                        client->counters.access_challenges++;
                        break;
                }
                buf = radius_msg_get_buf(reply);
                res = sendto(data->auth_sock, wpabuf_head(buf),
                             wpabuf_len(buf), 0,
                             (struct sockaddr *) from, fromlen);
                if (res < 0) {
                        perror("sendto[RADIUS SRV]");
                }
                radius_msg_free(sess->last_reply);
                sess->last_reply = reply;
                sess->last_from_port = from_port;
                hdr = radius_msg_get_hdr(msg);
                sess->last_identifier = hdr->identifier;
                os_memcpy(sess->last_authenticator, hdr->authenticator, 16);
        } else {
                data->counters.packets_dropped++;
                client->counters.packets_dropped++;
        }

        if (is_complete) {
                RADIUS_DEBUG("Removing completed session 0x%x after timeout",
                             sess->sess_id);
                eloop_cancel_timeout(radius_server_session_remove_timeout,
                                     data, sess);
                eloop_register_timeout(10, 0,
                                       radius_server_session_remove_timeout,
                                       data, sess);
        }

        return 0;
}


static void radius_server_receive_auth(int sock, void *eloop_ctx,
                                       void *sock_ctx)
{
        struct radius_server_data *data = eloop_ctx;
        u8 *buf = NULL;
        union {
                struct sockaddr_storage ss;
                struct sockaddr_in sin;
#ifdef CONFIG_IPV6
                struct sockaddr_in6 sin6;
#endif /* CONFIG_IPV6 */
        } from;
        socklen_t fromlen;
        int len;
        struct radius_client *client = NULL;
        struct radius_msg *msg = NULL;
        char abuf[50];
        int from_port = 0;

        buf = os_malloc(RADIUS_MAX_MSG_LEN);
        if (buf == NULL) {
                goto fail;
        }

        fromlen = sizeof(from);
        len = recvfrom(sock, buf, RADIUS_MAX_MSG_LEN, 0,
                       (struct sockaddr *) &from.ss, &fromlen);
        if (len < 0) {
                perror("recvfrom[radius_server]");
                goto fail;
        }

#ifdef CONFIG_IPV6
        if (data->ipv6) {
                if (inet_ntop(AF_INET6, &from.sin6.sin6_addr, abuf,
                              sizeof(abuf)) == NULL)
                        abuf[0] = '\0';
                from_port = ntohs(from.sin6.sin6_port);
                RADIUS_DEBUG("Received %d bytes from %s:%d",
                             len, abuf, from_port);

                client = radius_server_get_client(data,
                                                  (struct in_addr *)
                                                  &from.sin6.sin6_addr, 1);
        }
#endif /* CONFIG_IPV6 */

        if (!data->ipv6) {
                os_strlcpy(abuf, inet_ntoa(from.sin.sin_addr), sizeof(abuf));
                from_port = ntohs(from.sin.sin_port);
                RADIUS_DEBUG("Received %d bytes from %s:%d",
                             len, abuf, from_port);

                client = radius_server_get_client(data, &from.sin.sin_addr, 0);
        }

        RADIUS_DUMP("Received data", buf, len);

        if (client == NULL) {
                RADIUS_DEBUG("Unknown client %s - packet ignored", abuf);
                data->counters.invalid_requests++;
                goto fail;
        }

        msg = radius_msg_parse(buf, len);
        if (msg == NULL) {
                RADIUS_DEBUG("Parsing incoming RADIUS frame failed");
                data->counters.malformed_access_requests++;
                client->counters.malformed_access_requests++;
                goto fail;
        }

        os_free(buf);
        buf = NULL;

        if (wpa_debug_level <= MSG_MSGDUMP) {
                radius_msg_dump(msg);
        }

        if (radius_msg_get_hdr(msg)->code != RADIUS_CODE_ACCESS_REQUEST) {
                RADIUS_DEBUG("Unexpected RADIUS code %d",
                             radius_msg_get_hdr(msg)->code);
                data->counters.unknown_types++;
                client->counters.unknown_types++;
                goto fail;
        }

        data->counters.access_requests++;
        client->counters.access_requests++;

        if (radius_msg_verify_msg_auth(msg, (u8 *) client->shared_secret,
                                       client->shared_secret_len, NULL)) {
                RADIUS_DEBUG("Invalid Message-Authenticator from %s", abuf);
                data->counters.bad_authenticators++;
                client->counters.bad_authenticators++;
                goto fail;
        }

        if (radius_server_request(data, msg, (struct sockaddr *) &from,
                                  fromlen, client, abuf, from_port, NULL) ==
            -2)
                return; /* msg was stored with the session */

fail:
        radius_msg_free(msg);
        os_free(buf);
}


static int radius_server_disable_pmtu_discovery(int s)
{
        int r = -1;
#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
        /* Turn off Path MTU discovery on IPv4/UDP sockets. */
        int action = IP_PMTUDISC_DONT;
        r = setsockopt(s, IPPROTO_IP, IP_MTU_DISCOVER, &action,
                       sizeof(action));
        if (r == -1)
                wpa_printf(MSG_ERROR, "Failed to set IP_MTU_DISCOVER: "
                           "%s", strerror(errno));
#endif
        return r;
}


static int radius_server_open_socket(int port)
{
        int s;
        struct sockaddr_in addr;

        s = socket(PF_INET, SOCK_DGRAM, 0);
        if (s < 0) {
                perror("socket");
                return -1;
        }

        radius_server_disable_pmtu_discovery(s);

        os_memset(&addr, 0, sizeof(addr));
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port);
        if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
                perror("bind");
                close(s);
                return -1;
        }

        return s;
}


#ifdef CONFIG_IPV6
static int radius_server_open_socket6(int port)
{
        int s;
        struct sockaddr_in6 addr;

        s = socket(PF_INET6, SOCK_DGRAM, 0);
        if (s < 0) {
                perror("socket[IPv6]");
                return -1;
        }

        os_memset(&addr, 0, sizeof(addr));
        addr.sin6_family = AF_INET6;
        os_memcpy(&addr.sin6_addr, &in6addr_any, sizeof(in6addr_any));
        addr.sin6_port = htons(port);
        if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
                perror("bind");
                close(s);
                return -1;
        }

        return s;
}
#endif /* CONFIG_IPV6 */


static void radius_server_free_sessions(struct radius_server_data *data,
                                        struct radius_session *sessions)
{
        struct radius_session *session, *prev;

        session = sessions;
        while (session) {
                prev = session;
                session = session->next;
                radius_server_session_free(data, prev);
        }
}


static void radius_server_free_clients(struct radius_server_data *data,
                                       struct radius_client *clients)
{
        struct radius_client *client, *prev;

        client = clients;
        while (client) {
                prev = client;
                client = client->next;

                radius_server_free_sessions(data, prev->sessions);
                os_free(prev->shared_secret);
                os_free(prev);
        }
}


static struct radius_client *
radius_server_read_clients(const char *client_file, int ipv6)
{
        FILE *f;
        const int buf_size = 1024;
        char *buf, *pos;
        struct radius_client *clients, *tail, *entry;
        int line = 0, mask, failed = 0, i;
        struct in_addr addr;
#ifdef CONFIG_IPV6
        struct in6_addr addr6;
#endif /* CONFIG_IPV6 */
        unsigned int val;

        f = fopen(client_file, "r");
        if (f == NULL) {
                RADIUS_ERROR("Could not open client file '%s'", client_file);
                return NULL;
        }

        buf = os_malloc(buf_size);
        if (buf == NULL) {
                fclose(f);
                return NULL;
        }

        clients = tail = NULL;
        while (fgets(buf, buf_size, f)) {
                /* Configuration file format:
                 * 192.168.1.0/24 secret
                 * 192.168.1.2 secret
                 * fe80::211:22ff:fe33:4455/64 secretipv6
                 */
                line++;
                buf[buf_size - 1] = '\0';
                pos = buf;
                while (*pos != '\0' && *pos != '\n')
                        pos++;
                if (*pos == '\n')
                        *pos = '\0';
                if (*buf == '\0' || *buf == '#')
                        continue;

                pos = buf;
                while ((*pos >= '0' && *pos <= '9') || *pos == '.' ||
                       (*pos >= 'a' && *pos <= 'f') || *pos == ':' ||
                       (*pos >= 'A' && *pos <= 'F')) {
                        pos++;
                }

                if (*pos == '\0') {
                        failed = 1;
                        break;
                }

                if (*pos == '/') {
                        char *end;
                        *pos++ = '\0';
                        mask = strtol(pos, &end, 10);
                        if ((pos == end) ||
                            (mask < 0 || mask > (ipv6 ? 128 : 32))) {
                                failed = 1;
                                break;
                        }
                        pos = end;
                } else {
                        mask = ipv6 ? 128 : 32;
                        *pos++ = '\0';
                }

                if (!ipv6 && inet_aton(buf, &addr) == 0) {
                        failed = 1;
                        break;
                }
#ifdef CONFIG_IPV6
                if (ipv6 && inet_pton(AF_INET6, buf, &addr6) <= 0) {
                        if (inet_pton(AF_INET, buf, &addr) <= 0) {
                                failed = 1;
                                break;
                        }
                        /* Convert IPv4 address to IPv6 */
                        if (mask <= 32)
                                mask += (128 - 32);
                        os_memset(addr6.s6_addr, 0, 10);
                        addr6.s6_addr[10] = 0xff;
                        addr6.s6_addr[11] = 0xff;
                        os_memcpy(addr6.s6_addr + 12, (char *) &addr.s_addr,
                                  4);
                }
#endif /* CONFIG_IPV6 */

                while (*pos == ' ' || *pos == '\t') {
                        pos++;
                }

                if (*pos == '\0') {
                        failed = 1;
                        break;
                }

                entry = os_zalloc(sizeof(*entry));
                if (entry == NULL) {
                        failed = 1;
                        break;
                }
                entry->shared_secret = os_strdup(pos);
                if (entry->shared_secret == NULL) {
                        failed = 1;
                        os_free(entry);
                        break;
                }
                entry->shared_secret_len = os_strlen(entry->shared_secret);
                entry->addr.s_addr = addr.s_addr;
                if (!ipv6) {
                        val = 0;
                        for (i = 0; i < mask; i++)
                                val |= 1 << (31 - i);
                        entry->mask.s_addr = htonl(val);
                }
#ifdef CONFIG_IPV6
                if (ipv6) {
                        int offset = mask / 8;

                        os_memcpy(entry->addr6.s6_addr, addr6.s6_addr, 16);
                        os_memset(entry->mask6.s6_addr, 0xff, offset);
                        val = 0;
                        for (i = 0; i < (mask % 8); i++)
                                val |= 1 << (7 - i);
                        if (offset < 16)
                                entry->mask6.s6_addr[offset] = val;
                }
#endif /* CONFIG_IPV6 */

                if (tail == NULL) {
                        clients = tail = entry;
                } else {
                        tail->next = entry;
                        tail = entry;
                }
        }

        if (failed) {
                RADIUS_ERROR("Invalid line %d in '%s'", line, client_file);
                radius_server_free_clients(NULL, clients);
                clients = NULL;
        }

        os_free(buf);
        fclose(f);

        return clients;
}


struct radius_server_data *
radius_server_init(struct radius_server_conf *conf)
{
        struct radius_server_data *data;

#ifndef CONFIG_IPV6
        if (conf->ipv6) {
                fprintf(stderr, "RADIUS server compiled without IPv6 "
                        "support.\n");
                return NULL;
        }
#endif /* CONFIG_IPV6 */

        data = os_zalloc(sizeof(*data));
        if (data == NULL)
                return NULL;

        os_get_time(&data->start_time);
        data->conf_ctx = conf->conf_ctx;
        data->eap_sim_db_priv = conf->eap_sim_db_priv;
        data->ssl_ctx = conf->ssl_ctx;
        data->msg_ctx = conf->msg_ctx;
        data->ipv6 = conf->ipv6;
        if (conf->pac_opaque_encr_key) {
                data->pac_opaque_encr_key = os_malloc(16);
                os_memcpy(data->pac_opaque_encr_key, conf->pac_opaque_encr_key,
                          16);
        }
        if (conf->eap_fast_a_id) {
                data->eap_fast_a_id = os_malloc(conf->eap_fast_a_id_len);
                if (data->eap_fast_a_id) {
                        os_memcpy(data->eap_fast_a_id, conf->eap_fast_a_id,
                                  conf->eap_fast_a_id_len);
                        data->eap_fast_a_id_len = conf->eap_fast_a_id_len;
                }
        }
        if (conf->eap_fast_a_id_info)
                data->eap_fast_a_id_info = os_strdup(conf->eap_fast_a_id_info);
        data->eap_fast_prov = conf->eap_fast_prov;
        data->pac_key_lifetime = conf->pac_key_lifetime;
        data->pac_key_refresh_time = conf->pac_key_refresh_time;
        data->get_eap_user = conf->get_eap_user;
        data->eap_sim_aka_result_ind = conf->eap_sim_aka_result_ind;
        data->tnc = conf->tnc;
        data->wps = conf->wps;
        if (conf->eap_req_id_text) {
                data->eap_req_id_text = os_malloc(conf->eap_req_id_text_len);
                if (data->eap_req_id_text) {
                        os_memcpy(data->eap_req_id_text, conf->eap_req_id_text,
                                  conf->eap_req_id_text_len);
                        data->eap_req_id_text_len = conf->eap_req_id_text_len;
                }
        }

        data->clients = radius_server_read_clients(conf->client_file,
                                                   conf->ipv6);
        if (data->clients == NULL) {
                printf("No RADIUS clients configured.\n");
                radius_server_deinit(data);
                return NULL;
        }

#ifdef CONFIG_IPV6
        if (conf->ipv6)
                data->auth_sock = radius_server_open_socket6(conf->auth_port);
        else
#endif /* CONFIG_IPV6 */
        data->auth_sock = radius_server_open_socket(conf->auth_port);
        if (data->auth_sock < 0) {
                printf("Failed to open UDP socket for RADIUS authentication "
                       "server\n");
                radius_server_deinit(data);
                return NULL;
        }
        if (eloop_register_read_sock(data->auth_sock,
                                     radius_server_receive_auth,
                                     data, NULL)) {
                radius_server_deinit(data);
                return NULL;
        }

        return data;
}


void radius_server_deinit(struct radius_server_data *data)
{
        if (data == NULL)
                return;

        if (data->auth_sock >= 0) {
                eloop_unregister_read_sock(data->auth_sock);
                close(data->auth_sock);
        }

        radius_server_free_clients(data, data->clients);

        os_free(data->pac_opaque_encr_key);
        os_free(data->eap_fast_a_id);
        os_free(data->eap_fast_a_id_info);
        os_free(data->eap_req_id_text);
        os_free(data);
}


int radius_server_get_mib(struct radius_server_data *data, char *buf,
                          size_t buflen)
{
        int ret, uptime;
        unsigned int idx;
        char *end, *pos;
        struct os_time now;
        struct radius_client *cli;

        /* RFC 2619 - RADIUS Authentication Server MIB */

        if (data == NULL || buflen == 0)
                return 0;

        pos = buf;
        end = buf + buflen;

        os_get_time(&now);
        uptime = (now.sec - data->start_time.sec) * 100 +
                ((now.usec - data->start_time.usec) / 10000) % 100;
        ret = os_snprintf(pos, end - pos,
                          "RADIUS-AUTH-SERVER-MIB\n"
                          "radiusAuthServIdent=hostapd\n"
                          "radiusAuthServUpTime=%d\n"
                          "radiusAuthServResetTime=0\n"
                          "radiusAuthServConfigReset=4\n",
                          uptime);
        if (ret < 0 || ret >= end - pos) {
                *pos = '\0';
                return pos - buf;
        }
        pos += ret;

        ret = os_snprintf(pos, end - pos,
                          "radiusAuthServTotalAccessRequests=%u\n"
                          "radiusAuthServTotalInvalidRequests=%u\n"
                          "radiusAuthServTotalDupAccessRequests=%u\n"
                          "radiusAuthServTotalAccessAccepts=%u\n"
                          "radiusAuthServTotalAccessRejects=%u\n"
                          "radiusAuthServTotalAccessChallenges=%u\n"
                          "radiusAuthServTotalMalformedAccessRequests=%u\n"
                          "radiusAuthServTotalBadAuthenticators=%u\n"
                          "radiusAuthServTotalPacketsDropped=%u\n"
                          "radiusAuthServTotalUnknownTypes=%u\n",
                          data->counters.access_requests,
                          data->counters.invalid_requests,
                          data->counters.dup_access_requests,
                          data->counters.access_accepts,
                          data->counters.access_rejects,
                          data->counters.access_challenges,
                          data->counters.malformed_access_requests,
                          data->counters.bad_authenticators,
                          data->counters.packets_dropped,
                          data->counters.unknown_types);
        if (ret < 0 || ret >= end - pos) {
                *pos = '\0';
                return pos - buf;
        }
        pos += ret;

        for (cli = data->clients, idx = 0; cli; cli = cli->next, idx++) {
                char abuf[50], mbuf[50];
#ifdef CONFIG_IPV6
                if (data->ipv6) {
                        if (inet_ntop(AF_INET6, &cli->addr6, abuf,
                                      sizeof(abuf)) == NULL)
                                abuf[0] = '\0';
                        if (inet_ntop(AF_INET6, &cli->mask6, abuf,
                                      sizeof(mbuf)) == NULL)
                                mbuf[0] = '\0';
                }
#endif /* CONFIG_IPV6 */
                if (!data->ipv6) {
                        os_strlcpy(abuf, inet_ntoa(cli->addr), sizeof(abuf));
                        os_strlcpy(mbuf, inet_ntoa(cli->mask), sizeof(mbuf));
                }

                ret = os_snprintf(pos, end - pos,
                                  "radiusAuthClientIndex=%u\n"
                                  "radiusAuthClientAddress=%s/%s\n"
                                  "radiusAuthServAccessRequests=%u\n"
                                  "radiusAuthServDupAccessRequests=%u\n"
                                  "radiusAuthServAccessAccepts=%u\n"
                                  "radiusAuthServAccessRejects=%u\n"
                                  "radiusAuthServAccessChallenges=%u\n"
                                  "radiusAuthServMalformedAccessRequests=%u\n"
                                  "radiusAuthServBadAuthenticators=%u\n"
                                  "radiusAuthServPacketsDropped=%u\n"
                                  "radiusAuthServUnknownTypes=%u\n",
                                  idx,
                                  abuf, mbuf,
                                  cli->counters.access_requests,
                                  cli->counters.dup_access_requests,
                                  cli->counters.access_accepts,
                                  cli->counters.access_rejects,
                                  cli->counters.access_challenges,
                                  cli->counters.malformed_access_requests,
                                  cli->counters.bad_authenticators,
                                  cli->counters.packets_dropped,
                                  cli->counters.unknown_types);
                if (ret < 0 || ret >= end - pos) {
                        *pos = '\0';
                        return pos - buf;
                }
                pos += ret;
        }

        return pos - buf;
}


static int radius_server_get_eap_user(void *ctx, const u8 *identity,
                                      size_t identity_len, int phase2,
                                      struct eap_user *user)
{
        struct radius_session *sess = ctx;
        struct radius_server_data *data = sess->server;

        return data->get_eap_user(data->conf_ctx, identity, identity_len,
                                  phase2, user);
}


static const char * radius_server_get_eap_req_id_text(void *ctx, size_t *len)
{
        struct radius_session *sess = ctx;
        struct radius_server_data *data = sess->server;
        *len = data->eap_req_id_text_len;
        return data->eap_req_id_text;
}


static struct eapol_callbacks radius_server_eapol_cb =
{
        .get_eap_user = radius_server_get_eap_user,
        .get_eap_req_id_text = radius_server_get_eap_req_id_text,
};


void radius_server_eap_pending_cb(struct radius_server_data *data, void *ctx)
{
        struct radius_client *cli;
        struct radius_session *s, *sess = NULL;
        struct radius_msg *msg;

        if (data == NULL)
                return;

        for (cli = data->clients; cli; cli = cli->next) {
                for (s = cli->sessions; s; s = s->next) {
                        if (s->eap == ctx && s->last_msg) {
                                sess = s;
                                break;
                        }
                        if (sess)
                                break;
                }
                if (sess)
                        break;
        }

        if (sess == NULL) {
                RADIUS_DEBUG("No session matched callback ctx");
                return;
        }

        msg = sess->last_msg;
        sess->last_msg = NULL;
        eap_sm_pending_cb(sess->eap);
        if (radius_server_request(data, msg,
                                  (struct sockaddr *) &sess->last_from,
                                  sess->last_fromlen, cli,
                                  sess->last_from_addr,
                                  sess->last_from_port, sess) == -2)
                return; /* msg was stored with the session */

        radius_msg_free(msg);
}