text: /*
   * hostapd / IEEE 802.11 authentication (ACL)
   * Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
   *
   * This software may be distributed under the terms of the BSD license.
   * See README for more details.
   *
   * Access control list for IEEE 802.11 authentication can uses statically
   * configured ACL from configuration files or an external RADIUS server.
   * Results from external RADIUS queries are cached to allow faster
   * authentication frame processing.
   */
  
  #include "utils/includes.h"
  
  #include "utils/common.h"
  #include "utils/eloop.h"
  #include "crypto/sha1.h"
  #include "radius/radius.h"
  #include "radius/radius_client.h"
  #include "hostapd.h"
  #include "ap_config.h"
  #include "ap_drv_ops.h"
  #include "ieee802_11.h"
  #include "ieee802_1x.h"
  #include "ieee802_11_auth.h"
  
  #define RADIUS_ACL_TIMEOUT 30
  
  
  struct hostapd_cached_radius_acl {
  	struct os_reltime timestamp;
  	macaddr addr;
  	int accepted; /* HOSTAPD_ACL_* */
  	struct hostapd_cached_radius_acl *next;
  	u32 session_timeout;
  	u32 acct_interim_interval;
  	int vlan_id;
  	struct hostapd_sta_wpa_psk_short *psk;
  	char *identity;
  	char *radius_cui;
  };
  
  
  struct hostapd_acl_query_data {
  	struct os_reltime timestamp;
  	u8 radius_id;
  	macaddr addr;
  	u8 *auth_msg; /* IEEE 802.11 authentication frame from station */
  	size_t auth_msg_len;
  	struct hostapd_acl_query_data *next;
  };
  
  
  #ifndef CONFIG_NO_RADIUS
  static void hostapd_acl_cache_free_entry(struct hostapd_cached_radius_acl *e)
  {
  	os_free(e->identity);
  	os_free(e->radius_cui);
  	hostapd_free_psk_list(e->psk);
  	os_free(e);
  }
  
  
  static void hostapd_acl_cache_free(struct hostapd_cached_radius_acl *acl_cache)
  {
  	struct hostapd_cached_radius_acl *prev;
  
  	while (acl_cache) {
  		prev = acl_cache;
  		acl_cache = acl_cache->next;
  		hostapd_acl_cache_free_entry(prev);
  	}
  }
  
  
  static void copy_psk_list(struct hostapd_sta_wpa_psk_short **psk,
  			  struct hostapd_sta_wpa_psk_short *src)
  {
  	struct hostapd_sta_wpa_psk_short **copy_to;
  	struct hostapd_sta_wpa_psk_short *copy_from;
  
  	/* Copy PSK linked list */
  	copy_to = psk;
  	copy_from = src;
  	while (copy_from && copy_to) {
  		*copy_to = os_zalloc(sizeof(struct hostapd_sta_wpa_psk_short));
  		if (*copy_to == NULL)
  			break;
  		os_memcpy(*copy_to, copy_from,
  			  sizeof(struct hostapd_sta_wpa_psk_short));
  		copy_from = copy_from->next;
  		copy_to = &((*copy_to)->next);
  	}
  	if (copy_to)
  		*copy_to = NULL;
  }
  
  
  static int hostapd_acl_cache_get(struct hostapd_data *hapd, const u8 *addr,
  				 u32 *session_timeout,
  				 u32 *acct_interim_interval, int *vlan_id,
  				 struct hostapd_sta_wpa_psk_short **psk,
  				 char **identity, char **radius_cui)
  {
  	struct hostapd_cached_radius_acl *entry;
  	struct os_reltime now;
  
  	os_get_reltime(&now);
  
  	for (entry = hapd->acl_cache; entry; entry = entry->next) {
  		if (os_memcmp(entry->addr, addr, ETH_ALEN) != 0)
  			continue;
  
  		if (os_reltime_expired(&now, &entry->timestamp,
  				       RADIUS_ACL_TIMEOUT))
  			return -1; /* entry has expired */
  		if (entry->accepted == HOSTAPD_ACL_ACCEPT_TIMEOUT)
  			if (session_timeout)
  				*session_timeout = entry->session_timeout;
  		if (acct_interim_interval)
  			*acct_interim_interval =
  				entry->acct_interim_interval;
  		if (vlan_id)
  			*vlan_id = entry->vlan_id;
  		copy_psk_list(psk, entry->psk);
  		if (identity) {
  			if (entry->identity)
  				*identity = os_strdup(entry->identity);
  			else
  				*identity = NULL;
  		}
  		if (radius_cui) {
  			if (entry->radius_cui)
  				*radius_cui = os_strdup(entry->radius_cui);
  			else
  				*radius_cui = NULL;
  		}
  		return entry->accepted;
  	}
  
  	return -1;
  }
  #endif /* CONFIG_NO_RADIUS */
  
  
  static void hostapd_acl_query_free(struct hostapd_acl_query_data *query)
  {
  	if (query == NULL)
  		return;
  	os_free(query->auth_msg);
  	os_free(query);
  }
  
  
  #ifndef CONFIG_NO_RADIUS
  static int hostapd_radius_acl_query(struct hostapd_data *hapd, const u8 *addr,
  				    struct hostapd_acl_query_data *query)
  {
  	struct radius_msg *msg;
  	char buf[128];
  
  	query->radius_id = radius_client_get_id(hapd->radius);
  	msg = radius_msg_new(RADIUS_CODE_ACCESS_REQUEST, query->radius_id);
  	if (msg == NULL)
  		return -1;
  
  	radius_msg_make_authenticator(msg, addr, ETH_ALEN);
  
  	os_snprintf(buf, sizeof(buf), RADIUS_ADDR_FORMAT, MAC2STR(addr));
  	if (!radius_msg_add_attr(msg, RADIUS_ATTR_USER_NAME, (u8 *) buf,
  				 os_strlen(buf))) {
  		wpa_printf(MSG_DEBUG, "Could not add User-Name");
  		goto fail;
  	}
  
  	if (!radius_msg_add_attr_user_password(
  		    msg, (u8 *) buf, os_strlen(buf),
  		    hapd->conf->radius->auth_server->shared_secret,
  		    hapd->conf->radius->auth_server->shared_secret_len)) {
  		wpa_printf(MSG_DEBUG, "Could not add User-Password");
  		goto fail;
  	}
  
  	if (add_common_radius_attr(hapd, hapd->conf->radius_auth_req_attr,
  				   NULL, msg) < 0)
  		goto fail;
  
  	os_snprintf(buf, sizeof(buf), RADIUS_802_1X_ADDR_FORMAT,
  		    MAC2STR(addr));
  	if (!radius_msg_add_attr(msg, RADIUS_ATTR_CALLING_STATION_ID,
  				 (u8 *) buf, os_strlen(buf))) {
  		wpa_printf(MSG_DEBUG, "Could not add Calling-Station-Id");
  		goto fail;
  	}
  
  	os_snprintf(buf, sizeof(buf), "CONNECT 11Mbps 802.11b");
  	if (!radius_msg_add_attr(msg, RADIUS_ATTR_CONNECT_INFO,
  				 (u8 *) buf, os_strlen(buf))) {
  		wpa_printf(MSG_DEBUG, "Could not add Connect-Info");
  		goto fail;
  	}
  
  	if (radius_client_send(hapd->radius, msg, RADIUS_AUTH, addr) < 0)
  		goto fail;
  	return 0;
  
   fail:
  	radius_msg_free(msg);
  	return -1;
  }
  #endif /* CONFIG_NO_RADIUS */
  
  
  /**
   * hostapd_check_acl - Check a specified STA against accept/deny ACLs
   * @hapd: hostapd BSS data
   * @addr: MAC address of the STA
   * @vlan_id: Buffer for returning VLAN ID
   * Returns: HOSTAPD_ACL_ACCEPT, HOSTAPD_ACL_REJECT, or HOSTAPD_ACL_PENDING
   */
   int hostapd_check_acl(struct hostapd_data *hapd, const u8 *addr, int *vlan_id)
  {
  	if (hostapd_maclist_found(hapd->conf->accept_mac,
  				  hapd->conf->num_accept_mac, addr, vlan_id))
  		return HOSTAPD_ACL_ACCEPT;
  
  	if (hostapd_maclist_found(hapd->conf->deny_mac,
  				  hapd->conf->num_deny_mac, addr, vlan_id))
  		return HOSTAPD_ACL_REJECT;
  
  	if (hapd->conf->macaddr_acl == ACCEPT_UNLESS_DENIED)
  		return HOSTAPD_ACL_ACCEPT;
  	if (hapd->conf->macaddr_acl == DENY_UNLESS_ACCEPTED)
  		return HOSTAPD_ACL_REJECT;
  
  	return HOSTAPD_ACL_PENDING;
  }
  
  
  /**
   * hostapd_allowed_address - Check whether a specified STA can be authenticated
   * @hapd: hostapd BSS data
   * @addr: MAC address of the STA
   * @msg: Authentication message
   * @len: Length of msg in octets
   * @session_timeout: Buffer for returning session timeout (from RADIUS)
   * @acct_interim_interval: Buffer for returning account interval (from RADIUS)
   * @vlan_id: Buffer for returning VLAN ID
   * @psk: Linked list buffer for returning WPA PSK
   * @identity: Buffer for returning identity (from RADIUS)
   * @radius_cui: Buffer for returning CUI (from RADIUS)
   * Returns: HOSTAPD_ACL_ACCEPT, HOSTAPD_ACL_REJECT, or HOSTAPD_ACL_PENDING
   *
   * The caller is responsible for freeing the returned *identity and *radius_cui
   * values with os_free().
   */
  int hostapd_allowed_address(struct hostapd_data *hapd, const u8 *addr,
  			    const u8 *msg, size_t len, u32 *session_timeout,
  			    u32 *acct_interim_interval, int *vlan_id,
  			    struct hostapd_sta_wpa_psk_short **psk,
  			    char **identity, char **radius_cui)
  {
  	int res;
  
  	if (session_timeout)
  		*session_timeout = 0;
  	if (acct_interim_interval)
  		*acct_interim_interval = 0;
  	if (vlan_id)
  		*vlan_id = 0;
  	if (psk)
  		*psk = NULL;
  	if (identity)
  		*identity = NULL;
  	if (radius_cui)
  		*radius_cui = NULL;
  
  	res = hostapd_check_acl(hapd, addr, vlan_id);
  	if (res != HOSTAPD_ACL_PENDING)
  		return res;
  
  	if (hapd->conf->macaddr_acl == USE_EXTERNAL_RADIUS_AUTH) {
  #ifdef CONFIG_NO_RADIUS
  		return HOSTAPD_ACL_REJECT;
  #else /* CONFIG_NO_RADIUS */
  		struct hostapd_acl_query_data *query;
  
  		/* Check whether ACL cache has an entry for this station */
  		res = hostapd_acl_cache_get(hapd, addr, session_timeout,
  					    acct_interim_interval, vlan_id, psk,
  					    identity, radius_cui);
  		if (res == HOSTAPD_ACL_ACCEPT ||
  		    res == HOSTAPD_ACL_ACCEPT_TIMEOUT)
  			return res;
  		if (res == HOSTAPD_ACL_REJECT)
  			return HOSTAPD_ACL_REJECT;
  
  		query = hapd->acl_queries;
  		while (query) {
  			if (os_memcmp(query->addr, addr, ETH_ALEN) == 0) {
  				/* pending query in RADIUS retransmit queue;
  				 * do not generate a new one */
  				if (identity) {
  					os_free(*identity);
  					*identity = NULL;
  				}
  				if (radius_cui) {
  					os_free(*radius_cui);
  					*radius_cui = NULL;
  				}
  				return HOSTAPD_ACL_PENDING;
  			}
  			query = query->next;
  		}
  
  		if (!hapd->conf->radius->auth_server)
  			return HOSTAPD_ACL_REJECT;
  
  		/* No entry in the cache - query external RADIUS server */
  		query = os_zalloc(sizeof(*query));
  		if (query == NULL) {
  			wpa_printf(MSG_ERROR, "malloc for query data failed");
  			return HOSTAPD_ACL_REJECT;
  		}
  		os_get_reltime(&query->timestamp);
  		os_memcpy(query->addr, addr, ETH_ALEN);
  		if (hostapd_radius_acl_query(hapd, addr, query)) {
  			wpa_printf(MSG_DEBUG, "Failed to send Access-Request "
  				   "for ACL query.");
  			hostapd_acl_query_free(query);
  			return HOSTAPD_ACL_REJECT;
  		}
  
  		query->auth_msg = os_malloc(len);
  		if (query->auth_msg == NULL) {
  			wpa_printf(MSG_ERROR, "Failed to allocate memory for "
  				   "auth frame.");
  			hostapd_acl_query_free(query);
  			return HOSTAPD_ACL_REJECT;
  		}
  		os_memcpy(query->auth_msg, msg, len);
  		query->auth_msg_len = len;
  		query->next = hapd->acl_queries;
  		hapd->acl_queries = query;
  
  		/* Queued data will be processed in hostapd_acl_recv_radius()
  		 * when RADIUS server replies to the sent Access-Request. */
  		return HOSTAPD_ACL_PENDING;
  #endif /* CONFIG_NO_RADIUS */
  	}
  
  	return HOSTAPD_ACL_REJECT;
  }
  
  
  #ifndef CONFIG_NO_RADIUS
  static void hostapd_acl_expire_cache(struct hostapd_data *hapd,
  				     struct os_reltime *now)
  {
  	struct hostapd_cached_radius_acl *prev, *entry, *tmp;
  
  	prev = NULL;
  	entry = hapd->acl_cache;
  
  	while (entry) {
  		if (os_reltime_expired(now, &entry->timestamp,
  				       RADIUS_ACL_TIMEOUT)) {
  			wpa_printf(MSG_DEBUG, "Cached ACL entry for " MACSTR
  				   " has expired.", MAC2STR(entry->addr));
  			if (prev)
  				prev->next = entry->next;
  			else
  				hapd->acl_cache = entry->next;
  			hostapd_drv_set_radius_acl_expire(hapd, entry->addr);
  			tmp = entry;
  			entry = entry->next;
  			hostapd_acl_cache_free_entry(tmp);
  			continue;
  		}
  
  		prev = entry;
  		entry = entry->next;
  	}
  }
  
  
  static void hostapd_acl_expire_queries(struct hostapd_data *hapd,
  				       struct os_reltime *now)
  {
  	struct hostapd_acl_query_data *prev, *entry, *tmp;
  
  	prev = NULL;
  	entry = hapd->acl_queries;
  
  	while (entry) {
  		if (os_reltime_expired(now, &entry->timestamp,
  				       RADIUS_ACL_TIMEOUT)) {
  			wpa_printf(MSG_DEBUG, "ACL query for " MACSTR
  				   " has expired.", MAC2STR(entry->addr));
  			if (prev)
  				prev->next = entry->next;
  			else
  				hapd->acl_queries = entry->next;
  
  			tmp = entry;
  			entry = entry->next;
  			hostapd_acl_query_free(tmp);
  			continue;
  		}
  
  		prev = entry;
  		entry = entry->next;
  	}
  }
  
  
  /**
   * hostapd_acl_expire - ACL cache expiration callback
   * @hapd: struct hostapd_data *
   */
  void hostapd_acl_expire(struct hostapd_data *hapd)
  {
  	struct os_reltime now;
  
  	os_get_reltime(&now);
  	hostapd_acl_expire_cache(hapd, &now);
  	hostapd_acl_expire_queries(hapd, &now);
  }
  
  
  static void decode_tunnel_passwords(struct hostapd_data *hapd,
  				    const u8 *shared_secret,
  				    size_t shared_secret_len,
  				    struct radius_msg *msg,
  				    struct radius_msg *req,
  				    struct hostapd_cached_radius_acl *cache)
  {
  	int passphraselen;
  	char *passphrase, *strpassphrase;
  	size_t i;
  	struct hostapd_sta_wpa_psk_short *psk;
  
  	/*
  	 * Decode all tunnel passwords as PSK and save them into a linked list.
  	 */
  	for (i = 0; ; i++) {
  		passphrase = radius_msg_get_tunnel_password(
  			msg, &passphraselen, shared_secret, shared_secret_len,
  			req, i);
  		/*
  		 * Passphrase is NULL iff there is no i-th Tunnel-Password
  		 * attribute in msg.
  		 */
  		if (passphrase == NULL)
  			break;
  		/*
  		 * passphrase does not contain the NULL termination.
  		 * Add it here as pbkdf2_sha1() requires it.
  		 */
  		strpassphrase = os_zalloc(passphraselen + 1);
  		psk = os_zalloc(sizeof(struct hostapd_sta_wpa_psk_short));
  		if (strpassphrase && psk) {
  			os_memcpy(strpassphrase, passphrase, passphraselen);
  			pbkdf2_sha1(strpassphrase,
  				    hapd->conf->ssid.ssid,
  				    hapd->conf->ssid.ssid_len, 4096,
  				    psk->psk, PMK_LEN);
  			psk->next = cache->psk;
  			cache->psk = psk;
  			psk = NULL;
  		}
  		os_free(strpassphrase);
  		os_free(psk);
  		os_free(passphrase);
  	}
  }
  
  
  /**
   * hostapd_acl_recv_radius - Process incoming RADIUS Authentication messages
   * @msg: RADIUS response message
   * @req: RADIUS request message
   * @shared_secret: RADIUS shared secret
   * @shared_secret_len: Length of shared_secret in octets
   * @data: Context data (struct hostapd_data *)
   * Returns: RADIUS_RX_PROCESSED if RADIUS message was a reply to ACL query (and
   * was processed here) or RADIUS_RX_UNKNOWN if not.
   */
  static RadiusRxResult
  hostapd_acl_recv_radius(struct radius_msg *msg, struct radius_msg *req,
  			const u8 *shared_secret, size_t shared_secret_len,
  			void *data)
  {
  	struct hostapd_data *hapd = data;
  	struct hostapd_acl_query_data *query, *prev;
  	struct hostapd_cached_radius_acl *cache;
  	struct radius_hdr *hdr = radius_msg_get_hdr(msg);
  
  	query = hapd->acl_queries;
  	prev = NULL;
  	while (query) {
  		if (query->radius_id == hdr->identifier)
  			break;
  		prev = query;
  		query = query->next;
  	}
  	if (query == NULL)
  		return RADIUS_RX_UNKNOWN;
  
  	wpa_printf(MSG_DEBUG, "Found matching Access-Request for RADIUS "
  		   "message (id=%d)", query->radius_id);
  
  	if (radius_msg_verify(msg, shared_secret, shared_secret_len, req, 0)) {
  		wpa_printf(MSG_INFO, "Incoming RADIUS packet did not have "
  			   "correct authenticator - dropped\n");
  		return RADIUS_RX_INVALID_AUTHENTICATOR;
  	}
  
  	if (hdr->code != RADIUS_CODE_ACCESS_ACCEPT &&
  	    hdr->code != RADIUS_CODE_ACCESS_REJECT) {
  		wpa_printf(MSG_DEBUG, "Unknown RADIUS message code %d to ACL "
  			   "query", hdr->code);
  		return RADIUS_RX_UNKNOWN;
  	}
  
  	/* Insert Accept/Reject info into ACL cache */
  	cache = os_zalloc(sizeof(*cache));
  	if (cache == NULL) {
  		wpa_printf(MSG_DEBUG, "Failed to add ACL cache entry");
  		goto done;
  	}
  	os_get_reltime(&cache->timestamp);
  	os_memcpy(cache->addr, query->addr, sizeof(cache->addr));
  	if (hdr->code == RADIUS_CODE_ACCESS_ACCEPT) {
  		u8 *buf;
  		size_t len;
  
  		if (radius_msg_get_attr_int32(msg, RADIUS_ATTR_SESSION_TIMEOUT,
  					      &cache->session_timeout) == 0)
  			cache->accepted = HOSTAPD_ACL_ACCEPT_TIMEOUT;
  		else
  			cache->accepted = HOSTAPD_ACL_ACCEPT;
  
  		if (radius_msg_get_attr_int32(
  			    msg, RADIUS_ATTR_ACCT_INTERIM_INTERVAL,
  			    &cache->acct_interim_interval) == 0 &&
  		    cache->acct_interim_interval < 60) {
  			wpa_printf(MSG_DEBUG, "Ignored too small "
  				   "Acct-Interim-Interval %d for STA " MACSTR,
  				   cache->acct_interim_interval,
  				   MAC2STR(query->addr));
  			cache->acct_interim_interval = 0;
  		}
  
  		cache->vlan_id = radius_msg_get_vlanid(msg);
  
  		decode_tunnel_passwords(hapd, shared_secret, shared_secret_len,
  					msg, req, cache);
  
  		if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_USER_NAME,
  					    &buf, &len, NULL) == 0) {
  			cache->identity = os_zalloc(len + 1);
  			if (cache->identity)
  				os_memcpy(cache->identity, buf, len);
  		}
  		if (radius_msg_get_attr_ptr(
  			    msg, RADIUS_ATTR_CHARGEABLE_USER_IDENTITY,
  			    &buf, &len, NULL) == 0) {
  			cache->radius_cui = os_zalloc(len + 1);
  			if (cache->radius_cui)
  				os_memcpy(cache->radius_cui, buf, len);
  		}
  
  		if (hapd->conf->wpa_psk_radius == PSK_RADIUS_REQUIRED &&
  		    !cache->psk)
  			cache->accepted = HOSTAPD_ACL_REJECT;
  
  		if (cache->vlan_id &&
  		    !hostapd_vlan_id_valid(hapd->conf->vlan, cache->vlan_id)) {
  			hostapd_logger(hapd, query->addr,
  				       HOSTAPD_MODULE_RADIUS,
  				       HOSTAPD_LEVEL_INFO,
  				       "Invalid VLAN ID %d received from RADIUS server",
  				       cache->vlan_id);
  			cache->vlan_id = 0;
  		}
  		if (hapd->conf->ssid.dynamic_vlan == DYNAMIC_VLAN_REQUIRED &&
  		    !cache->vlan_id)
  			cache->accepted = HOSTAPD_ACL_REJECT;
  	} else
  		cache->accepted = HOSTAPD_ACL_REJECT;
  	cache->next = hapd->acl_cache;
  	hapd->acl_cache = cache;
  
  #ifdef CONFIG_DRIVER_RADIUS_ACL
  	hostapd_drv_set_radius_acl_auth(hapd, query->addr, cache->accepted,
  					cache->session_timeout);
  #else /* CONFIG_DRIVER_RADIUS_ACL */
  #ifdef NEED_AP_MLME
  	/* Re-send original authentication frame for 802.11 processing */
  	wpa_printf(MSG_DEBUG, "Re-sending authentication frame after "
  		   "successful RADIUS ACL query");
  	ieee802_11_mgmt(hapd, query->auth_msg, query->auth_msg_len, NULL);
  #endif /* NEED_AP_MLME */
  #endif /* CONFIG_DRIVER_RADIUS_ACL */
  
   done:
  	if (prev == NULL)
  		hapd->acl_queries = query->next;
  	else
  		prev->next = query->next;
  
  	hostapd_acl_query_free(query);
  
  	return RADIUS_RX_PROCESSED;
  }
  #endif /* CONFIG_NO_RADIUS */
  
  
  /**
   * hostapd_acl_init: Initialize IEEE 802.11 ACL
   * @hapd: hostapd BSS data
   * Returns: 0 on success, -1 on failure
   */
  int hostapd_acl_init(struct hostapd_data *hapd)
  {
  #ifndef CONFIG_NO_RADIUS
  	if (radius_client_register(hapd->radius, RADIUS_AUTH,
  				   hostapd_acl_recv_radius, hapd))
  		return -1;
  #endif /* CONFIG_NO_RADIUS */
  
  	return 0;
  }
  
  
  /**
   * hostapd_acl_deinit - Deinitialize IEEE 802.11 ACL
   * @hapd: hostapd BSS data
   */
  void hostapd_acl_deinit(struct hostapd_data *hapd)
  {
  	struct hostapd_acl_query_data *query, *prev;
  
  #ifndef CONFIG_NO_RADIUS
  	hostapd_acl_cache_free(hapd->acl_cache);
  #endif /* CONFIG_NO_RADIUS */
  
  	query = hapd->acl_queries;
  	while (query) {
  		prev = query;
  		query = query->next;
  		hostapd_acl_query_free(prev);
  	}
  }
  
  
  void hostapd_free_psk_list(struct hostapd_sta_wpa_psk_short *psk)
  {
  	while (psk) {
  		struct hostapd_sta_wpa_psk_short *prev = psk;
  		psk = psk->next;
  		os_free(prev);
  	}
  }
  