contrib/hostapd-0.4.9/ieee802_11_auth.c

   1 /*
   2  * Host AP (software wireless LAN access point) user space daemon for
   3  * Host AP kernel driver / IEEE 802.11 authentication (ACL)
   4  * Copyright (c) 2003-2005, Jouni Malinen <jkmaline@cc.hut.fi>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * Alternatively, this software may be distributed under the terms of BSD
  11  * license.
  12  *
  13  * See README and COPYING for more details.
  14  */
  15
  16 #include <stdlib.h>
  17 #include <stdio.h>
  18 #include <string.h>
  19 #include <time.h>
  20 #include <netinet/in.h>
  21 #include <arpa/inet.h>
  22 #include <sys/types.h>
  23 #include <sys/socket.h>
  24
  25 #include "hostapd.h"
  26 #include "ieee802_11.h"
  27 #include "ieee802_11_auth.h"
  28 #include "radius.h"
  29 #include "radius_client.h"
  30 #include "eloop.h"
  31 #include "hostap_common.h"
  32
  33 #define RADIUS_ACL_TIMEOUT 30
  34
  35
  36 struct hostapd_cached_radius_acl {
  37         time_t timestamp;
  38         macaddr addr;
  39         int accepted; /* HOSTAPD_ACL_* */
  40         struct hostapd_cached_radius_acl *next;
  41         u32 session_timeout;
  42         u32 acct_interim_interval;
  43 };
  44
  45
  46 struct hostapd_acl_query_data {
  47         time_t timestamp;
  48         u8 radius_id;
  49         macaddr addr;
  50         u8 *auth_msg; /* IEEE 802.11 authentication frame from station */
  51         size_t auth_msg_len;
  52         struct hostapd_acl_query_data *next;
  53 };
  54
  55
  56 static void hostapd_acl_cache_free(struct hostapd_cached_radius_acl *acl_cache)
  57 {
  58         struct hostapd_cached_radius_acl *prev;
  59
  60         while (acl_cache) {
  61                 prev = acl_cache;
  62                 acl_cache = acl_cache->next;
  63                 free(prev);
  64         }
  65 }
  66
  67
  68 static int hostapd_acl_cache_get(struct hostapd_data *hapd, u8 *addr,
  69                                  u32 *session_timeout,
  70                                  u32 *acct_interim_interval)
  71 {
  72         struct hostapd_cached_radius_acl *entry;
  73         time_t now;
  74
  75         time(&now);
  76         entry = hapd->acl_cache;
  77
  78         while (entry) {
  79                 if (memcmp(entry->addr, addr, ETH_ALEN) == 0) {
  80                         if (now - entry->timestamp > RADIUS_ACL_TIMEOUT)
  81                                 return -1; /* entry has expired */
  82                         if (entry->accepted == HOSTAPD_ACL_ACCEPT_TIMEOUT)
  83                                 *session_timeout = entry->session_timeout;
  84                         *acct_interim_interval = entry->acct_interim_interval;
  85                         return entry->accepted;
  86                 }
  87
  88                 entry = entry->next;
  89         }
  90
  91         return -1;
  92 }
  93
  94
  95 static void hostapd_acl_query_free(struct hostapd_acl_query_data *query)
  96 {
  97         if (query == NULL)
  98                 return;
  99         free(query->auth_msg);
 100         free(query);
 101 }
 102
 103
 104 static int hostapd_radius_acl_query(hostapd *hapd, u8 *addr,
 105                                     struct hostapd_acl_query_data *query)
 106 {
 107         struct radius_msg *msg;
 108         char buf[128];
 109
 110         query->radius_id = radius_client_get_id(hapd->radius);
 111         msg = radius_msg_new(RADIUS_CODE_ACCESS_REQUEST, query->radius_id);
 112         if (msg == NULL)
 113                 return -1;
 114
 115         radius_msg_make_authenticator(msg, addr, ETH_ALEN);
 116
 117         snprintf(buf, sizeof(buf), RADIUS_ADDR_FORMAT, MAC2STR(addr));
 118         if (!radius_msg_add_attr(msg, RADIUS_ATTR_USER_NAME, (u8 *) buf,
 119                                  strlen(buf))) {
 120                 printf("Could not add User-Name\n");
 121                 goto fail;
 122         }
 123
 124         if (!radius_msg_add_attr_user_password(
 125                     msg, (u8 *) buf, strlen(buf),
 126                     hapd->conf->radius->auth_server->shared_secret,
 127                     hapd->conf->radius->auth_server->shared_secret_len)) {
 128                 printf("Could not add User-Password\n");
 129                 goto fail;
 130         }
 131
 132         if (hapd->conf->own_ip_addr.af == AF_INET &&
 133             !radius_msg_add_attr(msg, RADIUS_ATTR_NAS_IP_ADDRESS,
 134                                  (u8 *) &hapd->conf->own_ip_addr.u.v4, 4)) {
 135                 printf("Could not add NAS-IP-Address\n");
 136                 goto fail;
 137         }
 138
 139 #ifdef CONFIG_IPV6
 140         if (hapd->conf->own_ip_addr.af == AF_INET6 &&
 141             !radius_msg_add_attr(msg, RADIUS_ATTR_NAS_IPV6_ADDRESS,
 142                                  (u8 *) &hapd->conf->own_ip_addr.u.v6, 16)) {
 143                 printf("Could not add NAS-IPv6-Address\n");
 144                 goto fail;
 145         }
 146 #endif /* CONFIG_IPV6 */
 147
 148         if (hapd->conf->nas_identifier &&
 149             !radius_msg_add_attr(msg, RADIUS_ATTR_NAS_IDENTIFIER,
 150                                  (u8 *) hapd->conf->nas_identifier,
 151                                  strlen(hapd->conf->nas_identifier))) {
 152                 printf("Could not add NAS-Identifier\n");
 153                 goto fail;
 154         }
 155
 156         snprintf(buf, sizeof(buf), RADIUS_802_1X_ADDR_FORMAT ":%s",
 157                  MAC2STR(hapd->own_addr), hapd->conf->ssid);
 158         if (!radius_msg_add_attr(msg, RADIUS_ATTR_CALLED_STATION_ID,
 159                                  (u8 *) buf, strlen(buf))) {
 160                 printf("Could not add Called-Station-Id\n");
 161                 goto fail;
 162         }
 163
 164         snprintf(buf, sizeof(buf), RADIUS_802_1X_ADDR_FORMAT,
 165                  MAC2STR(addr));
 166         if (!radius_msg_add_attr(msg, RADIUS_ATTR_CALLING_STATION_ID,
 167                                  (u8 *) buf, strlen(buf))) {
 168                 printf("Could not add Calling-Station-Id\n");
 169                 goto fail;
 170         }
 171
 172         if (!radius_msg_add_attr_int32(msg, RADIUS_ATTR_NAS_PORT_TYPE,
 173                                        RADIUS_NAS_PORT_TYPE_IEEE_802_11)) {
 174                 printf("Could not add NAS-Port-Type\n");
 175                 goto fail;
 176         }
 177
 178         snprintf(buf, sizeof(buf), "CONNECT 11Mbps 802.11b");
 179         if (!radius_msg_add_attr(msg, RADIUS_ATTR_CONNECT_INFO,
 180                                  (u8 *) buf, strlen(buf))) {
 181                 printf("Could not add Connect-Info\n");
 182                 goto fail;
 183         }
 184
 185         radius_client_send(hapd->radius, msg, RADIUS_AUTH, addr);
 186         return 0;
 187
 188  fail:
 189         radius_msg_free(msg);
 190         free(msg);
 191         return -1;
 192 }
 193
 194
 195 int hostapd_allowed_address(hostapd *hapd, u8 *addr, u8 *msg, size_t len,
 196                             u32 *session_timeout, u32 *acct_interim_interval)
 197 {
 198         *session_timeout = 0;
 199         *acct_interim_interval = 0;
 200
 201         if (hostapd_maclist_found(hapd->conf->accept_mac,
 202                                   hapd->conf->num_accept_mac, addr))
 203                 return HOSTAPD_ACL_ACCEPT;
 204
 205         if (hostapd_maclist_found(hapd->conf->deny_mac,
 206                                   hapd->conf->num_deny_mac, addr))
 207                 return HOSTAPD_ACL_REJECT;
 208
 209         if (hapd->conf->macaddr_acl == ACCEPT_UNLESS_DENIED)
 210                 return HOSTAPD_ACL_ACCEPT;
 211         if (hapd->conf->macaddr_acl == DENY_UNLESS_ACCEPTED)
 212                 return HOSTAPD_ACL_REJECT;
 213
 214         if (hapd->conf->macaddr_acl == USE_EXTERNAL_RADIUS_AUTH) {
 215                 struct hostapd_acl_query_data *query;
 216
 217                 /* Check whether ACL cache has an entry for this station */
 218                 int res = hostapd_acl_cache_get(hapd, addr, session_timeout,
 219                                                 acct_interim_interval);
 220                 if (res == HOSTAPD_ACL_ACCEPT ||
 221                     res == HOSTAPD_ACL_ACCEPT_TIMEOUT)
 222                         return res;
 223                 if (res == HOSTAPD_ACL_REJECT)
 224                         return HOSTAPD_ACL_REJECT;
 225
 226                 query = hapd->acl_queries;
 227                 while (query) {
 228                         if (memcmp(query->addr, addr, ETH_ALEN) == 0) {
 229                                 /* pending query in RADIUS retransmit queue;
 230                                  * do not generate a new one */
 231                                 return HOSTAPD_ACL_PENDING;
 232                         }
 233                         query = query->next;
 234                 }
 235
 236                 if (!hapd->conf->radius->auth_server)
 237                         return HOSTAPD_ACL_REJECT;
 238
 239                 /* No entry in the cache - query external RADIUS server */
 240                 query = malloc(sizeof(*query));
 241                 if (query == NULL) {
 242                         printf("malloc for query data failed\n");
 243                         return HOSTAPD_ACL_REJECT;
 244                 }
 245                 memset(query, 0, sizeof(*query));
 246                 time(&query->timestamp);
 247                 memcpy(query->addr, addr, ETH_ALEN);
 248                 if (hostapd_radius_acl_query(hapd, addr, query)) {
 249                         printf("Failed to send Access-Request for ACL "
 250                                "query.\n");
 251                         hostapd_acl_query_free(query);
 252                         return HOSTAPD_ACL_REJECT;
 253                 }
 254
 255                 query->auth_msg = malloc(len);
 256                 if (query->auth_msg == NULL) {
 257                         printf("Failed to allocate memory for auth frame.\n");
 258                         hostapd_acl_query_free(query);
 259                         return HOSTAPD_ACL_REJECT;
 260                 }
 261                 memcpy(query->auth_msg, msg, len);
 262                 query->auth_msg_len = len;
 263                 query->next = hapd->acl_queries;
 264                 hapd->acl_queries = query;
 265
 266                 /* Queued data will be processed in hostapd_acl_recv_radius()
 267                  * when RADIUS server replies to the sent Access-Request. */
 268                 return HOSTAPD_ACL_PENDING;
 269         }
 270
 271         return HOSTAPD_ACL_REJECT;
 272 }
 273
 274
 275 static void hostapd_acl_expire_cache(hostapd *hapd, time_t now)
 276 {
 277         struct hostapd_cached_radius_acl *prev, *entry, *tmp;
 278
 279         prev = NULL;
 280         entry = hapd->acl_cache;
 281
 282         while (entry) {
 283                 if (now - entry->timestamp > RADIUS_ACL_TIMEOUT) {
 284                         HOSTAPD_DEBUG(HOSTAPD_DEBUG_MINIMAL,
 285                                       "Cached ACL entry for " MACSTR
 286                                       " has expired.\n", MAC2STR(entry->addr));
 287                         if (prev)
 288                                 prev->next = entry->next;
 289                         else
 290                                 hapd->acl_cache = entry->next;
 291
 292                         tmp = entry;
 293                         entry = entry->next;
 294                         free(tmp);
 295                         continue;
 296                 }
 297
 298                 prev = entry;
 299                 entry = entry->next;
 300         }
 301 }
 302
 303
 304 static void hostapd_acl_expire_queries(hostapd *hapd, time_t now)
 305 {
 306         struct hostapd_acl_query_data *prev, *entry, *tmp;
 307
 308         prev = NULL;
 309         entry = hapd->acl_queries;
 310
 311         while (entry) {
 312                 if (now - entry->timestamp > RADIUS_ACL_TIMEOUT) {
 313                         HOSTAPD_DEBUG(HOSTAPD_DEBUG_MINIMAL,
 314                                       "ACL query for " MACSTR
 315                                       " has expired.\n", MAC2STR(entry->addr));
 316                         if (prev)
 317                                 prev->next = entry->next;
 318                         else
 319                                 hapd->acl_queries = entry->next;
 320
 321                         tmp = entry;
 322                         entry = entry->next;
 323                         hostapd_acl_query_free(tmp);
 324                         continue;
 325                 }
 326
 327                 prev = entry;
 328                 entry = entry->next;
 329         }
 330 }
 331
 332
 333 static void hostapd_acl_expire(void *eloop_ctx, void *timeout_ctx)
 334 {
 335         hostapd *hapd = eloop_ctx;
 336         time_t now;
 337
 338         time(&now);
 339         hostapd_acl_expire_cache(hapd, now);
 340         hostapd_acl_expire_queries(hapd, now);
 341
 342         eloop_register_timeout(10, 0, hostapd_acl_expire, hapd, NULL);
 343 }
 344
 345
 346 /* Return 0 if RADIUS message was a reply to ACL query (and was processed here)
 347  * or -1 if not. */
 348 static RadiusRxResult
 349 hostapd_acl_recv_radius(struct radius_msg *msg, struct radius_msg *req,
 350                         u8 *shared_secret, size_t shared_secret_len,
 351                         void *data)
 352 {
 353         struct hostapd_data *hapd = data;
 354         struct hostapd_acl_query_data *query, *prev;
 355         struct hostapd_cached_radius_acl *cache;
 356
 357         query = hapd->acl_queries;
 358         prev = NULL;
 359         while (query) {
 360                 if (query->radius_id == msg->hdr->identifier)
 361                         break;
 362                 prev = query;
 363                 query = query->next;
 364         }
 365         if (query == NULL)
 366                 return RADIUS_RX_UNKNOWN;
 367
 368         HOSTAPD_DEBUG(HOSTAPD_DEBUG_MINIMAL, "Found matching Access-Request "
 369                       "for RADIUS message (id=%d)\n", query->radius_id);
 370
 371         if (radius_msg_verify(msg, shared_secret, shared_secret_len, req, 0)) {
 372                 printf("Incoming RADIUS packet did not have correct "
 373                        "authenticator - dropped\n");
 374                 return RADIUS_RX_INVALID_AUTHENTICATOR;
 375         }
 376
 377         if (msg->hdr->code != RADIUS_CODE_ACCESS_ACCEPT &&
 378             msg->hdr->code != RADIUS_CODE_ACCESS_REJECT) {
 379                 printf("Unknown RADIUS message code %d to ACL query\n",
 380                        msg->hdr->code);
 381                 return RADIUS_RX_UNKNOWN;
 382         }
 383
 384         /* Insert Accept/Reject info into ACL cache */
 385         cache = malloc(sizeof(*cache));
 386         if (cache == NULL) {
 387                 printf("Failed to add ACL cache entry\n");
 388                 goto done;
 389         }
 390         memset(cache, 0, sizeof(*cache));
 391         time(&cache->timestamp);
 392         memcpy(cache->addr, query->addr, sizeof(cache->addr));
 393         if (msg->hdr->code == RADIUS_CODE_ACCESS_ACCEPT) {
 394                 if (radius_msg_get_attr_int32(msg, RADIUS_ATTR_SESSION_TIMEOUT,
 395                                               &cache->session_timeout) == 0)
 396                         cache->accepted = HOSTAPD_ACL_ACCEPT_TIMEOUT;
 397                 else
 398                         cache->accepted = HOSTAPD_ACL_ACCEPT;
 399
 400                 if (radius_msg_get_attr_int32(
 401                             msg, RADIUS_ATTR_ACCT_INTERIM_INTERVAL,
 402                             &cache->acct_interim_interval) == 0 &&
 403                     cache->acct_interim_interval < 60) {
 404                         HOSTAPD_DEBUG(HOSTAPD_DEBUG_MINIMAL, "Ignored too "
 405                                       "small Acct-Interim-Interval %d for "
 406                                       "STA " MACSTR "\n",
 407                                       cache->acct_interim_interval,
 408                                       MAC2STR(query->addr));
 409                         cache->acct_interim_interval = 0;
 410                 }
 411         } else
 412                 cache->accepted = HOSTAPD_ACL_REJECT;
 413         cache->next = hapd->acl_cache;
 414         hapd->acl_cache = cache;
 415
 416         /* Re-send original authentication frame for 802.11 processing */
 417         HOSTAPD_DEBUG(HOSTAPD_DEBUG_MINIMAL, "Re-sending authentication frame "
 418                       "after successful RADIUS ACL query\n");
 419         ieee802_11_mgmt(hapd, query->auth_msg, query->auth_msg_len,
 420                         WLAN_FC_STYPE_AUTH);
 421
 422  done:
 423         if (prev == NULL)
 424                 hapd->acl_queries = query->next;
 425         else
 426                 prev->next = query->next;
 427
 428         hostapd_acl_query_free(query);
 429
 430         return RADIUS_RX_PROCESSED;
 431 }
 432
 433
 434 int hostapd_acl_init(hostapd *hapd)
 435 {
 436         if (radius_client_register(hapd->radius, RADIUS_AUTH,
 437                                    hostapd_acl_recv_radius, hapd))
 438                 return -1;
 439
 440         eloop_register_timeout(10, 0, hostapd_acl_expire, hapd, NULL);
 441
 442         return 0;
 443 }
 444
 445
 446 void hostapd_acl_deinit(hostapd *hapd)
 447 {
 448         struct hostapd_acl_query_data *query, *prev;
 449
 450         hostapd_acl_cache_free(hapd->acl_cache);
 451
 452         query = hapd->acl_queries;
 453         while (query) {
 454                 prev = query;
 455                 query = query->next;
 456                 hostapd_acl_query_free(prev);
 457         }
 458 }