1/*
2 * hostapd / WMM (Wi-Fi Multimedia)
3 * Copyright 2002-2003, Instant802 Networks, Inc.
4 * Copyright 2005-2006, Devicescape Software, Inc.
5 * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
6 *
7 * This software may be distributed under the terms of the BSD license.
8 * See README for more details.
9 */
10
11#include "utils/includes.h"
12
13#include "utils/common.h"
14#include "common/ieee802_11_defs.h"
15#include "common/ieee802_11_common.h"
16#include "hostapd.h"
17#include "ieee802_11.h"
18#include "sta_info.h"
19#include "ap_config.h"
20#include "ap_drv_ops.h"
21#include "wmm.h"
22
23
24static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci)
25{
26	u8 ret;
27	ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK;
28	if (acm)
29		ret |= WMM_AC_ACM;
30	ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK;
31	return ret;
32}
33
34
35static inline u8 wmm_ecw(int ecwmin, int ecwmax)
36{
37	return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) |
38		((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK);
39}
40
41
42/*
43 * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association
44 * Response frames.
45 */
46u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid)
47{
48	u8 *pos = eid;
49	struct wmm_parameter_element *wmm =
50		(struct wmm_parameter_element *) (pos + 2);
51	int e;
52
53	if (!hapd->conf->wmm_enabled)
54		return eid;
55	eid[0] = WLAN_EID_VENDOR_SPECIFIC;
56	wmm->oui[0] = 0x00;
57	wmm->oui[1] = 0x50;
58	wmm->oui[2] = 0xf2;
59	wmm->oui_type = WMM_OUI_TYPE;
60	wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT;
61	wmm->version = WMM_VERSION;
62	wmm->qos_info = hapd->parameter_set_count & 0xf;
63
64	if (hapd->conf->wmm_uapsd &&
65	    (hapd->iface->drv_flags & WPA_DRIVER_FLAGS_AP_UAPSD))
66		wmm->qos_info |= 0x80;
67
68	wmm->reserved = 0;
69
70	/* fill in a parameter set record for each AC */
71	for (e = 0; e < 4; e++) {
72		struct wmm_ac_parameter *ac = &wmm->ac[e];
73		struct hostapd_wmm_ac_params *acp =
74			&hapd->iconf->wmm_ac_params[e];
75
76		ac->aci_aifsn = wmm_aci_aifsn(acp->aifs,
77					      acp->admission_control_mandatory,
78					      e);
79		ac->cw = wmm_ecw(acp->cwmin, acp->cwmax);
80		ac->txop_limit = host_to_le16(acp->txop_limit);
81	}
82
83	pos = (u8 *) (wmm + 1);
84	eid[1] = pos - eid - 2; /* element length */
85
86	return pos;
87}
88
89
90/*
91 * This function is called when a station sends an association request with
92 * WMM info element. The function returns 1 on success or 0 on any error in WMM
93 * element. eid does not include Element ID and Length octets.
94 */
95int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid, size_t len)
96{
97	struct wmm_information_element *wmm;
98
99	wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len);
100
101	if (len < sizeof(struct wmm_information_element)) {
102		wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)",
103			   (unsigned long) len);
104		return 0;
105	}
106
107	wmm = (struct wmm_information_element *) eid;
108	wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x  "
109		   "OUI type %d  OUI sub-type %d  version %d  QoS info 0x%x",
110		   wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type,
111		   wmm->oui_subtype, wmm->version, wmm->qos_info);
112	if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT ||
113	    wmm->version != WMM_VERSION) {
114		wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version");
115		return 0;
116	}
117
118	return 1;
119}
120
121
122static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr,
123			    const struct wmm_tspec_element *tspec,
124			    u8 action_code, u8 dialogue_token, u8 status_code)
125{
126	u8 buf[256];
127	struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf;
128	struct wmm_tspec_element *t = (struct wmm_tspec_element *)
129		m->u.action.u.wmm_action.variable;
130	int len;
131
132	hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211,
133		       HOSTAPD_LEVEL_DEBUG,
134		       "action response - reason %d", status_code);
135	os_memset(buf, 0, sizeof(buf));
136	m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
137					WLAN_FC_STYPE_ACTION);
138	os_memcpy(m->da, addr, ETH_ALEN);
139	os_memcpy(m->sa, hapd->own_addr, ETH_ALEN);
140	os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN);
141	m->u.action.category = WLAN_ACTION_WMM;
142	m->u.action.u.wmm_action.action_code = action_code;
143	m->u.action.u.wmm_action.dialog_token = dialogue_token;
144	m->u.action.u.wmm_action.status_code = status_code;
145	os_memcpy(t, tspec, sizeof(struct wmm_tspec_element));
146	len = ((u8 *) (t + 1)) - buf;
147
148	if (hostapd_drv_send_mlme(hapd, m, len, 0) < 0)
149		wpa_printf(MSG_INFO, "wmm_send_action: send failed");
150}
151
152
153int wmm_process_tspec(struct wmm_tspec_element *tspec)
154{
155	u64 medium_time;
156	unsigned int pps, duration;
157	unsigned int up, psb, dir, tid;
158	u16 val, surplus;
159
160	up = (tspec->ts_info[1] >> 3) & 0x07;
161	psb = (tspec->ts_info[1] >> 2) & 0x01;
162	dir = (tspec->ts_info[0] >> 5) & 0x03;
163	tid = (tspec->ts_info[0] >> 1) & 0x0f;
164	wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d",
165		   up, psb, dir, tid);
166	val = le_to_host16(tspec->nominal_msdu_size);
167	wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s",
168		   val & 0x7fff, val & 0x8000 ? " (fixed)" : "");
169	wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps",
170		   le_to_host32(tspec->mean_data_rate));
171	wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps",
172		   le_to_host32(tspec->minimum_phy_rate));
173	val = le_to_host16(tspec->surplus_bandwidth_allowance);
174	wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u",
175		   val >> 13, 10000 * (val & 0x1fff) / 0x2000);
176
177	val = le_to_host16(tspec->nominal_msdu_size);
178	if (val == 0) {
179		wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)");
180		return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
181	}
182	/* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */
183	pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val;
184	wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d",
185		   pps);
186
187	if (le_to_host32(tspec->minimum_phy_rate) < 1000000) {
188		wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate");
189		return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
190	}
191
192	duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 /
193		(le_to_host32(tspec->minimum_phy_rate) / 1000000) +
194		50 /* FIX: proper SIFS + ACK duration */;
195
196	/* unsigned binary number with an implicit binary point after the
197	 * leftmost 3 bits, i.e., 0x2000 = 1.0 */
198	surplus = le_to_host16(tspec->surplus_bandwidth_allowance);
199	if (surplus <= 0x2000) {
200		wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not "
201			   "greater than unity");
202		return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
203	}
204
205	medium_time = (u64) surplus * pps * duration / 0x2000;
206	wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %lu",
207		   (unsigned long) medium_time);
208
209	/*
210	 * TODO: store list of granted (and still active) TSPECs and check
211	 * whether there is available medium time for this request. For now,
212	 * just refuse requests that would by themselves take very large
213	 * portion of the available bandwidth.
214	 */
215	if (medium_time > 750000) {
216		wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over "
217			   "75%% of available bandwidth");
218		return WMM_ADDTS_STATUS_REFUSED;
219	}
220
221	/* Convert to 32 microseconds per second unit */
222	tspec->medium_time = host_to_le16(medium_time / 32);
223
224	return WMM_ADDTS_STATUS_ADMISSION_ACCEPTED;
225}
226
227
228static void wmm_addts_req(struct hostapd_data *hapd,
229			  const struct ieee80211_mgmt *mgmt,
230			  struct wmm_tspec_element *tspec, size_t len)
231{
232	const u8 *end = ((const u8 *) mgmt) + len;
233	int res;
234
235	if ((const u8 *) (tspec + 1) > end) {
236		wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request");
237		return;
238	}
239
240	wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC "
241		   "from " MACSTR,
242		   mgmt->u.action.u.wmm_action.dialog_token,
243		   MAC2STR(mgmt->sa));
244
245	res = wmm_process_tspec(tspec);
246	wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res);
247
248	wmm_send_action(hapd, mgmt->sa, tspec, WMM_ACTION_CODE_ADDTS_RESP,
249			mgmt->u.action.u.wmm_action.dialog_token, res);
250}
251
252
253void hostapd_wmm_action(struct hostapd_data *hapd,
254			const struct ieee80211_mgmt *mgmt, size_t len)
255{
256	int action_code;
257	int left = len - IEEE80211_HDRLEN - 4;
258	const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4;
259	struct ieee802_11_elems elems;
260	struct sta_info *sta = ap_get_sta(hapd, mgmt->sa);
261
262	/* check that the request comes from a valid station */
263	if (!sta ||
264	    (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) !=
265	    (WLAN_STA_ASSOC | WLAN_STA_WMM)) {
266		hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
267			       HOSTAPD_LEVEL_DEBUG,
268			       "wmm action received is not from associated wmm"
269			       " station");
270		/* TODO: respond with action frame refused status code */
271		return;
272	}
273
274	if (left < 0)
275		return; /* not a valid WMM Action frame */
276
277	/* extract the tspec info element */
278	if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) {
279		hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
280			       HOSTAPD_LEVEL_DEBUG,
281			       "hostapd_wmm_action - could not parse wmm "
282			       "action");
283		/* TODO: respond with action frame invalid parameters status
284		 * code */
285		return;
286	}
287
288	if (!elems.wmm_tspec ||
289	    elems.wmm_tspec_len != (sizeof(struct wmm_tspec_element) - 2)) {
290		hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
291			       HOSTAPD_LEVEL_DEBUG,
292			       "hostapd_wmm_action - missing or wrong length "
293			       "tspec");
294		/* TODO: respond with action frame invalid parameters status
295		 * code */
296		return;
297	}
298
299	/* TODO: check the request is for an AC with ACM set, if not, refuse
300	 * request */
301
302	action_code = mgmt->u.action.u.wmm_action.action_code;
303	switch (action_code) {
304	case WMM_ACTION_CODE_ADDTS_REQ:
305		wmm_addts_req(hapd, mgmt, (struct wmm_tspec_element *)
306			      (elems.wmm_tspec - 2), len);
307		return;
308#if 0
309	/* TODO: needed for client implementation */
310	case WMM_ACTION_CODE_ADDTS_RESP:
311		wmm_setup_request(hapd, mgmt, len);
312		return;
313	/* TODO: handle station teardown requests */
314	case WMM_ACTION_CODE_DELTS:
315		wmm_teardown(hapd, mgmt, len);
316		return;
317#endif
318	}
319
320	hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
321		       HOSTAPD_LEVEL_DEBUG,
322		       "hostapd_wmm_action - unknown action code %d",
323		       action_code);
324}
325