/* * Generic advertisement service (GAS) query (hostapd) * Copyright (c) 2009, Atheros Communications * Copyright (c) 2011-2017, Qualcomm Atheros, Inc. * Copyright (c) 2011-2014, Jouni Malinen * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include "includes.h" #include "common.h" #include "utils/eloop.h" #include "utils/list.h" #include "common/ieee802_11_defs.h" #include "common/gas.h" #include "common/wpa_ctrl.h" #include "hostapd.h" #include "sta_info.h" #include "ap_drv_ops.h" #include "gas_query_ap.h" /** GAS query timeout in seconds */ #define GAS_QUERY_TIMEOUT_PERIOD 2 /* GAS query wait-time / duration in ms */ #define GAS_QUERY_WAIT_TIME_INITIAL 1000 #define GAS_QUERY_WAIT_TIME_COMEBACK 150 /** * struct gas_query_pending - Pending GAS query */ struct gas_query_pending { struct dl_list list; struct gas_query_ap *gas; u8 addr[ETH_ALEN]; u8 dialog_token; u8 next_frag_id; unsigned int wait_comeback:1; unsigned int offchannel_tx_started:1; unsigned int retry:1; int freq; u16 status_code; struct wpabuf *req; struct wpabuf *adv_proto; struct wpabuf *resp; struct os_reltime last_oper; void (*cb)(void *ctx, const u8 *dst, u8 dialog_token, enum gas_query_ap_result result, const struct wpabuf *adv_proto, const struct wpabuf *resp, u16 status_code); void *ctx; u8 sa[ETH_ALEN]; }; /** * struct gas_query_ap - Internal GAS query data */ struct gas_query_ap { struct hostapd_data *hapd; void *msg_ctx; struct dl_list pending; /* struct gas_query_pending */ struct gas_query_pending *current; }; static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx); static void gas_query_timeout(void *eloop_data, void *user_ctx); static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx); static void gas_query_tx_initial_req(struct gas_query_ap *gas, struct gas_query_pending *query); static int gas_query_new_dialog_token(struct gas_query_ap *gas, const u8 *dst); static int ms_from_time(struct os_reltime *last) { struct os_reltime now, res; os_get_reltime(&now); os_reltime_sub(&now, last, &res); return res.sec * 1000 + res.usec / 1000; } /** * gas_query_ap_init - Initialize GAS query component * @hapd: Pointer to hostapd data * Returns: Pointer to GAS query data or %NULL on failure */ struct gas_query_ap * gas_query_ap_init(struct hostapd_data *hapd, void *msg_ctx) { struct gas_query_ap *gas; gas = os_zalloc(sizeof(*gas)); if (!gas) return NULL; gas->hapd = hapd; gas->msg_ctx = msg_ctx; dl_list_init(&gas->pending); return gas; } static const char * gas_result_txt(enum gas_query_ap_result result) { switch (result) { case GAS_QUERY_AP_SUCCESS: return "SUCCESS"; case GAS_QUERY_AP_FAILURE: return "FAILURE"; case GAS_QUERY_AP_TIMEOUT: return "TIMEOUT"; case GAS_QUERY_AP_PEER_ERROR: return "PEER_ERROR"; case GAS_QUERY_AP_INTERNAL_ERROR: return "INTERNAL_ERROR"; case GAS_QUERY_AP_DELETED_AT_DEINIT: return "DELETED_AT_DEINIT"; } return "N/A"; } static void gas_query_free(struct gas_query_pending *query, int del_list) { if (del_list) dl_list_del(&query->list); wpabuf_free(query->req); wpabuf_free(query->adv_proto); wpabuf_free(query->resp); os_free(query); } static void gas_query_done(struct gas_query_ap *gas, struct gas_query_pending *query, enum gas_query_ap_result result) { wpa_msg(gas->msg_ctx, MSG_INFO, GAS_QUERY_DONE "addr=" MACSTR " dialog_token=%u freq=%d status_code=%u result=%s", MAC2STR(query->addr), query->dialog_token, query->freq, query->status_code, gas_result_txt(result)); if (gas->current == query) gas->current = NULL; eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query); eloop_cancel_timeout(gas_query_timeout, gas, query); eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query); dl_list_del(&query->list); query->cb(query->ctx, query->addr, query->dialog_token, result, query->adv_proto, query->resp, query->status_code); gas_query_free(query, 0); } /** * gas_query_ap_deinit - Deinitialize GAS query component * @gas: GAS query data from gas_query_init() */ void gas_query_ap_deinit(struct gas_query_ap *gas) { struct gas_query_pending *query, *next; if (gas == NULL) return; dl_list_for_each_safe(query, next, &gas->pending, struct gas_query_pending, list) gas_query_done(gas, query, GAS_QUERY_AP_DELETED_AT_DEINIT); os_free(gas); } static struct gas_query_pending * gas_query_get_pending(struct gas_query_ap *gas, const u8 *addr, u8 dialog_token) { struct gas_query_pending *q; dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) { if (os_memcmp(q->addr, addr, ETH_ALEN) == 0 && q->dialog_token == dialog_token) return q; } return NULL; } static int gas_query_append(struct gas_query_pending *query, const u8 *data, size_t len) { if (wpabuf_resize(&query->resp, len) < 0) { wpa_printf(MSG_DEBUG, "GAS: No memory to store the response"); return -1; } wpabuf_put_data(query->resp, data, len); return 0; } void gas_query_ap_tx_status(struct gas_query_ap *gas, const u8 *dst, const u8 *data, size_t data_len, int ok) { struct gas_query_pending *query; int dur; if (!gas || !gas->current) { wpa_printf(MSG_DEBUG, "GAS: Unexpected TX status: dst=" MACSTR " ok=%d - no query in progress", MAC2STR(dst), ok); return; } query = gas->current; dur = ms_from_time(&query->last_oper); wpa_printf(MSG_DEBUG, "GAS: TX status: dst=" MACSTR " ok=%d query=%p dialog_token=%u dur=%d ms", MAC2STR(dst), ok, query, query->dialog_token, dur); if (os_memcmp(dst, query->addr, ETH_ALEN) != 0) { wpa_printf(MSG_DEBUG, "GAS: TX status for unexpected destination"); return; } os_get_reltime(&query->last_oper); eloop_cancel_timeout(gas_query_timeout, gas, query); if (!ok) { wpa_printf(MSG_DEBUG, "GAS: No ACK to GAS request"); eloop_register_timeout(0, 250000, gas_query_timeout, gas, query); } else { eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0, gas_query_timeout, gas, query); } if (query->wait_comeback && !query->retry) { eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query); eloop_register_timeout( 0, (GAS_QUERY_WAIT_TIME_COMEBACK + 10) * 1000, gas_query_rx_comeback_timeout, gas, query); } } static int pmf_in_use(struct hostapd_data *hapd, const u8 *addr) { struct sta_info *sta; sta = ap_get_sta(hapd, addr); return sta && (sta->flags & WLAN_STA_MFP); } static int gas_query_tx(struct gas_query_ap *gas, struct gas_query_pending *query, struct wpabuf *req, unsigned int wait_time) { int res, prot = pmf_in_use(gas->hapd, query->addr); wpa_printf(MSG_DEBUG, "GAS: Send action frame to " MACSTR " len=%u " "freq=%d prot=%d using src addr " MACSTR, MAC2STR(query->addr), (unsigned int) wpabuf_len(req), query->freq, prot, MAC2STR(query->sa)); if (prot) { u8 *categ = wpabuf_mhead_u8(req); *categ = WLAN_ACTION_PROTECTED_DUAL; } os_get_reltime(&query->last_oper); res = hostapd_drv_send_action(gas->hapd, query->freq, wait_time, query->addr, wpabuf_head(req), wpabuf_len(req)); return res; } static void gas_query_tx_comeback_req(struct gas_query_ap *gas, struct gas_query_pending *query) { struct wpabuf *req; unsigned int wait_time; req = gas_build_comeback_req(query->dialog_token); if (req == NULL) { gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); return; } wait_time = (query->retry || !query->offchannel_tx_started) ? GAS_QUERY_WAIT_TIME_INITIAL : GAS_QUERY_WAIT_TIME_COMEBACK; if (gas_query_tx(gas, query, req, wait_time) < 0) { wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to " MACSTR, MAC2STR(query->addr)); gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); } wpabuf_free(req); } static void gas_query_rx_comeback_timeout(void *eloop_data, void *user_ctx) { struct gas_query_ap *gas = eloop_data; struct gas_query_pending *query = user_ctx; int dialog_token; wpa_printf(MSG_DEBUG, "GAS: No response to comeback request received (retry=%u)", query->retry); if (gas->current != query || query->retry) return; dialog_token = gas_query_new_dialog_token(gas, query->addr); if (dialog_token < 0) return; wpa_printf(MSG_DEBUG, "GAS: Retry GAS query due to comeback response timeout"); query->retry = 1; query->dialog_token = dialog_token; *(wpabuf_mhead_u8(query->req) + 2) = dialog_token; query->wait_comeback = 0; query->next_frag_id = 0; wpabuf_free(query->adv_proto); query->adv_proto = NULL; eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query); eloop_cancel_timeout(gas_query_timeout, gas, query); gas_query_tx_initial_req(gas, query); } static void gas_query_tx_comeback_timeout(void *eloop_data, void *user_ctx) { struct gas_query_ap *gas = eloop_data; struct gas_query_pending *query = user_ctx; wpa_printf(MSG_DEBUG, "GAS: Comeback timeout for request to " MACSTR, MAC2STR(query->addr)); gas_query_tx_comeback_req(gas, query); } static void gas_query_tx_comeback_req_delay(struct gas_query_ap *gas, struct gas_query_pending *query, u16 comeback_delay) { unsigned int secs, usecs; secs = (comeback_delay * 1024) / 1000000; usecs = comeback_delay * 1024 - secs * 1000000; wpa_printf(MSG_DEBUG, "GAS: Send comeback request to " MACSTR " in %u secs %u usecs", MAC2STR(query->addr), secs, usecs); eloop_cancel_timeout(gas_query_tx_comeback_timeout, gas, query); eloop_register_timeout(secs, usecs, gas_query_tx_comeback_timeout, gas, query); } static void gas_query_rx_initial(struct gas_query_ap *gas, struct gas_query_pending *query, const u8 *adv_proto, const u8 *resp, size_t len, u16 comeback_delay) { wpa_printf(MSG_DEBUG, "GAS: Received initial response from " MACSTR " (dialog_token=%u comeback_delay=%u)", MAC2STR(query->addr), query->dialog_token, comeback_delay); query->adv_proto = wpabuf_alloc_copy(adv_proto, 2 + adv_proto[1]); if (query->adv_proto == NULL) { gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); return; } if (comeback_delay) { eloop_cancel_timeout(gas_query_timeout, gas, query); query->wait_comeback = 1; gas_query_tx_comeback_req_delay(gas, query, comeback_delay); return; } /* Query was completed without comeback mechanism */ if (gas_query_append(query, resp, len) < 0) { gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); return; } gas_query_done(gas, query, GAS_QUERY_AP_SUCCESS); } static void gas_query_rx_comeback(struct gas_query_ap *gas, struct gas_query_pending *query, const u8 *adv_proto, const u8 *resp, size_t len, u8 frag_id, u8 more_frags, u16 comeback_delay) { wpa_printf(MSG_DEBUG, "GAS: Received comeback response from " MACSTR " (dialog_token=%u frag_id=%u more_frags=%u " "comeback_delay=%u)", MAC2STR(query->addr), query->dialog_token, frag_id, more_frags, comeback_delay); eloop_cancel_timeout(gas_query_rx_comeback_timeout, gas, query); if ((size_t) 2 + adv_proto[1] != wpabuf_len(query->adv_proto) || os_memcmp(adv_proto, wpabuf_head(query->adv_proto), wpabuf_len(query->adv_proto)) != 0) { wpa_printf(MSG_DEBUG, "GAS: Advertisement Protocol changed " "between initial and comeback response from " MACSTR, MAC2STR(query->addr)); gas_query_done(gas, query, GAS_QUERY_AP_PEER_ERROR); return; } if (comeback_delay) { if (frag_id) { wpa_printf(MSG_DEBUG, "GAS: Invalid comeback response " "with non-zero frag_id and comeback_delay " "from " MACSTR, MAC2STR(query->addr)); gas_query_done(gas, query, GAS_QUERY_AP_PEER_ERROR); return; } gas_query_tx_comeback_req_delay(gas, query, comeback_delay); return; } if (frag_id != query->next_frag_id) { wpa_printf(MSG_DEBUG, "GAS: Unexpected frag_id in response " "from " MACSTR, MAC2STR(query->addr)); if (frag_id + 1 == query->next_frag_id) { wpa_printf(MSG_DEBUG, "GAS: Drop frame as possible " "retry of previous fragment"); return; } gas_query_done(gas, query, GAS_QUERY_AP_PEER_ERROR); return; } query->next_frag_id++; if (gas_query_append(query, resp, len) < 0) { gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); return; } if (more_frags) { gas_query_tx_comeback_req(gas, query); return; } gas_query_done(gas, query, GAS_QUERY_AP_SUCCESS); } /** * gas_query_ap_rx - Indicate reception of a Public Action or Protected Dual * frame * @gas: GAS query data from gas_query_init() * @sa: Source MAC address of the Action frame * @categ: Category of the Action frame * @data: Payload of the Action frame * @len: Length of @data * @freq: Frequency (in MHz) on which the frame was received * Returns: 0 if the Public Action frame was a GAS frame or -1 if not */ int gas_query_ap_rx(struct gas_query_ap *gas, const u8 *sa, u8 categ, const u8 *data, size_t len, int freq) { struct gas_query_pending *query; u8 action, dialog_token, frag_id = 0, more_frags = 0; u16 comeback_delay, resp_len; const u8 *pos, *adv_proto; int prot, pmf; unsigned int left; if (!gas || len < 4) return -1; pos = data; action = *pos++; dialog_token = *pos++; if (action != WLAN_PA_GAS_INITIAL_RESP && action != WLAN_PA_GAS_COMEBACK_RESP) return -1; /* Not a GAS response */ prot = categ == WLAN_ACTION_PROTECTED_DUAL; pmf = pmf_in_use(gas->hapd, sa); if (prot && !pmf) { wpa_printf(MSG_DEBUG, "GAS: Drop unexpected protected GAS frame when PMF is disabled"); return 0; } if (!prot && pmf) { wpa_printf(MSG_DEBUG, "GAS: Drop unexpected unprotected GAS frame when PMF is enabled"); return 0; } query = gas_query_get_pending(gas, sa, dialog_token); if (query == NULL) { wpa_printf(MSG_DEBUG, "GAS: No pending query found for " MACSTR " dialog token %u", MAC2STR(sa), dialog_token); return -1; } wpa_printf(MSG_DEBUG, "GAS: Response in %d ms from " MACSTR, ms_from_time(&query->last_oper), MAC2STR(sa)); if (query->wait_comeback && action == WLAN_PA_GAS_INITIAL_RESP) { wpa_printf(MSG_DEBUG, "GAS: Unexpected initial response from " MACSTR " dialog token %u when waiting for comeback " "response", MAC2STR(sa), dialog_token); return 0; } if (!query->wait_comeback && action == WLAN_PA_GAS_COMEBACK_RESP) { wpa_printf(MSG_DEBUG, "GAS: Unexpected comeback response from " MACSTR " dialog token %u when waiting for initial " "response", MAC2STR(sa), dialog_token); return 0; } query->status_code = WPA_GET_LE16(pos); pos += 2; if (query->status_code == WLAN_STATUS_QUERY_RESP_OUTSTANDING && action == WLAN_PA_GAS_COMEBACK_RESP) { wpa_printf(MSG_DEBUG, "GAS: Allow non-zero status for outstanding comeback response"); } else if (query->status_code != WLAN_STATUS_SUCCESS) { wpa_printf(MSG_DEBUG, "GAS: Query to " MACSTR " dialog token " "%u failed - status code %u", MAC2STR(sa), dialog_token, query->status_code); gas_query_done(gas, query, GAS_QUERY_AP_FAILURE); return 0; } if (action == WLAN_PA_GAS_COMEBACK_RESP) { if (pos + 1 > data + len) return 0; frag_id = *pos & 0x7f; more_frags = (*pos & 0x80) >> 7; pos++; } /* Comeback Delay */ if (pos + 2 > data + len) return 0; comeback_delay = WPA_GET_LE16(pos); pos += 2; /* Advertisement Protocol element */ if (pos + 2 > data + len || pos + 2 + pos[1] > data + len) { wpa_printf(MSG_DEBUG, "GAS: No room for Advertisement " "Protocol element in the response from " MACSTR, MAC2STR(sa)); return 0; } if (*pos != WLAN_EID_ADV_PROTO) { wpa_printf(MSG_DEBUG, "GAS: Unexpected Advertisement " "Protocol element ID %u in response from " MACSTR, *pos, MAC2STR(sa)); return 0; } adv_proto = pos; pos += 2 + pos[1]; /* Query Response Length */ if (pos + 2 > data + len) { wpa_printf(MSG_DEBUG, "GAS: No room for GAS Response Length"); return 0; } resp_len = WPA_GET_LE16(pos); pos += 2; left = data + len - pos; if (resp_len > left) { wpa_printf(MSG_DEBUG, "GAS: Truncated Query Response in " "response from " MACSTR, MAC2STR(sa)); return 0; } if (resp_len < left) { wpa_printf(MSG_DEBUG, "GAS: Ignore %u octets of extra data " "after Query Response from " MACSTR, left - resp_len, MAC2STR(sa)); } if (action == WLAN_PA_GAS_COMEBACK_RESP) gas_query_rx_comeback(gas, query, adv_proto, pos, resp_len, frag_id, more_frags, comeback_delay); else gas_query_rx_initial(gas, query, adv_proto, pos, resp_len, comeback_delay); return 0; } static void gas_query_timeout(void *eloop_data, void *user_ctx) { struct gas_query_ap *gas = eloop_data; struct gas_query_pending *query = user_ctx; wpa_printf(MSG_DEBUG, "GAS: No response received for query to " MACSTR " dialog token %u", MAC2STR(query->addr), query->dialog_token); gas_query_done(gas, query, GAS_QUERY_AP_TIMEOUT); } static int gas_query_dialog_token_available(struct gas_query_ap *gas, const u8 *dst, u8 dialog_token) { struct gas_query_pending *q; dl_list_for_each(q, &gas->pending, struct gas_query_pending, list) { if (os_memcmp(dst, q->addr, ETH_ALEN) == 0 && dialog_token == q->dialog_token) return 0; } return 1; } static void gas_query_tx_initial_req(struct gas_query_ap *gas, struct gas_query_pending *query) { if (gas_query_tx(gas, query, query->req, GAS_QUERY_WAIT_TIME_INITIAL) < 0) { wpa_printf(MSG_DEBUG, "GAS: Failed to send Action frame to " MACSTR, MAC2STR(query->addr)); gas_query_done(gas, query, GAS_QUERY_AP_INTERNAL_ERROR); return; } gas->current = query; wpa_printf(MSG_DEBUG, "GAS: Starting query timeout for dialog token %u", query->dialog_token); eloop_register_timeout(GAS_QUERY_TIMEOUT_PERIOD, 0, gas_query_timeout, gas, query); } static int gas_query_new_dialog_token(struct gas_query_ap *gas, const u8 *dst) { static int next_start = 0; int dialog_token; for (dialog_token = 0; dialog_token < 256; dialog_token++) { if (gas_query_dialog_token_available( gas, dst, (next_start + dialog_token) % 256)) break; } if (dialog_token == 256) return -1; /* Too many pending queries */ dialog_token = (next_start + dialog_token) % 256; next_start = (dialog_token + 1) % 256; return dialog_token; } /** * gas_query_ap_req - Request a GAS query * @gas: GAS query data from gas_query_init() * @dst: Destination MAC address for the query * @freq: Frequency (in MHz) for the channel on which to send the query * @req: GAS query payload (to be freed by gas_query module in case of success * return) * @cb: Callback function for reporting GAS query result and response * @ctx: Context pointer to use with the @cb call * Returns: dialog token (>= 0) on success or -1 on failure */ int gas_query_ap_req(struct gas_query_ap *gas, const u8 *dst, int freq, struct wpabuf *req, void (*cb)(void *ctx, const u8 *dst, u8 dialog_token, enum gas_query_ap_result result, const struct wpabuf *adv_proto, const struct wpabuf *resp, u16 status_code), void *ctx) { struct gas_query_pending *query; int dialog_token; if (!gas || wpabuf_len(req) < 3) return -1; dialog_token = gas_query_new_dialog_token(gas, dst); if (dialog_token < 0) return -1; query = os_zalloc(sizeof(*query)); if (query == NULL) return -1; query->gas = gas; os_memcpy(query->addr, dst, ETH_ALEN); query->dialog_token = dialog_token; query->freq = freq; query->cb = cb; query->ctx = ctx; query->req = req; dl_list_add(&gas->pending, &query->list); *(wpabuf_mhead_u8(req) + 2) = dialog_token; wpa_msg(gas->msg_ctx, MSG_INFO, GAS_QUERY_START "addr=" MACSTR " dialog_token=%u freq=%d", MAC2STR(query->addr), query->dialog_token, query->freq); gas_query_tx_initial_req(gas, query); return dialog_token; }