/*
* Generic advertisement service (GAS) query (hostapd)
* Copyright (c) 2009, Atheros Communications
* Copyright (c) 2011-2017, Qualcomm Atheros, Inc.
* Copyright (c) 2011-2014, Jouni Malinen <j@w1.fi>
*
* 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;
}