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
24 /* TODO: maintain separate sequence and fragment numbers for each AC
25 * TODO: IGMP snooping to track which multicasts to forward - and use QOS-DATA
26 * if only WMM stations are receiving a certain group */
27
28
wmm_aci_aifsn(int aifsn,int acm,int aci)29 static inline u8 wmm_aci_aifsn(int aifsn, int acm, int aci)
30 {
31 u8 ret;
32 ret = (aifsn << WMM_AC_AIFNS_SHIFT) & WMM_AC_AIFSN_MASK;
33 if (acm)
34 ret |= WMM_AC_ACM;
35 ret |= (aci << WMM_AC_ACI_SHIFT) & WMM_AC_ACI_MASK;
36 return ret;
37 }
38
39
wmm_ecw(int ecwmin,int ecwmax)40 static inline u8 wmm_ecw(int ecwmin, int ecwmax)
41 {
42 return ((ecwmin << WMM_AC_ECWMIN_SHIFT) & WMM_AC_ECWMIN_MASK) |
43 ((ecwmax << WMM_AC_ECWMAX_SHIFT) & WMM_AC_ECWMAX_MASK);
44 }
45
46
47 /*
48 * Add WMM Parameter Element to Beacon, Probe Response, and (Re)Association
49 * Response frames.
50 */
hostapd_eid_wmm(struct hostapd_data * hapd,u8 * eid)51 u8 * hostapd_eid_wmm(struct hostapd_data *hapd, u8 *eid)
52 {
53 u8 *pos = eid;
54 struct wmm_parameter_element *wmm =
55 (struct wmm_parameter_element *) (pos + 2);
56 int e;
57
58 if (!hapd->conf->wmm_enabled)
59 return eid;
60 eid[0] = WLAN_EID_VENDOR_SPECIFIC;
61 wmm->oui[0] = 0x00;
62 wmm->oui[1] = 0x50;
63 wmm->oui[2] = 0xf2;
64 wmm->oui_type = WMM_OUI_TYPE;
65 wmm->oui_subtype = WMM_OUI_SUBTYPE_PARAMETER_ELEMENT;
66 wmm->version = WMM_VERSION;
67 wmm->qos_info = hapd->parameter_set_count & 0xf;
68
69 if (hapd->conf->wmm_uapsd &&
70 (hapd->iface->drv_flags & WPA_DRIVER_FLAGS_AP_UAPSD))
71 wmm->qos_info |= 0x80;
72
73 wmm->reserved = 0;
74
75 /* fill in a parameter set record for each AC */
76 for (e = 0; e < 4; e++) {
77 struct wmm_ac_parameter *ac = &wmm->ac[e];
78 struct hostapd_wmm_ac_params *acp =
79 &hapd->iconf->wmm_ac_params[e];
80
81 ac->aci_aifsn = wmm_aci_aifsn(acp->aifs,
82 acp->admission_control_mandatory,
83 e);
84 ac->cw = wmm_ecw(acp->cwmin, acp->cwmax);
85 ac->txop_limit = host_to_le16(acp->txop_limit);
86 }
87
88 pos = (u8 *) (wmm + 1);
89 eid[1] = pos - eid - 2; /* element length */
90
91 return pos;
92 }
93
94
95 /*
96 * This function is called when a station sends an association request with
97 * WMM info element. The function returns 1 on success or 0 on any error in WMM
98 * element. eid does not include Element ID and Length octets.
99 */
hostapd_eid_wmm_valid(struct hostapd_data * hapd,const u8 * eid,size_t len)100 int hostapd_eid_wmm_valid(struct hostapd_data *hapd, const u8 *eid, size_t len)
101 {
102 struct wmm_information_element *wmm;
103
104 wpa_hexdump(MSG_MSGDUMP, "WMM IE", eid, len);
105
106 if (len < sizeof(struct wmm_information_element)) {
107 wpa_printf(MSG_DEBUG, "Too short WMM IE (len=%lu)",
108 (unsigned long) len);
109 return 0;
110 }
111
112 wmm = (struct wmm_information_element *) eid;
113 wpa_printf(MSG_DEBUG, "Validating WMM IE: OUI %02x:%02x:%02x "
114 "OUI type %d OUI sub-type %d version %d QoS info 0x%x",
115 wmm->oui[0], wmm->oui[1], wmm->oui[2], wmm->oui_type,
116 wmm->oui_subtype, wmm->version, wmm->qos_info);
117 if (wmm->oui_subtype != WMM_OUI_SUBTYPE_INFORMATION_ELEMENT ||
118 wmm->version != WMM_VERSION) {
119 wpa_printf(MSG_DEBUG, "Unsupported WMM IE Subtype/Version");
120 return 0;
121 }
122
123 return 1;
124 }
125
126
wmm_send_action(struct hostapd_data * hapd,const u8 * addr,const struct wmm_tspec_element * tspec,u8 action_code,u8 dialogue_token,u8 status_code)127 static void wmm_send_action(struct hostapd_data *hapd, const u8 *addr,
128 const struct wmm_tspec_element *tspec,
129 u8 action_code, u8 dialogue_token, u8 status_code)
130 {
131 u8 buf[256];
132 struct ieee80211_mgmt *m = (struct ieee80211_mgmt *) buf;
133 struct wmm_tspec_element *t = (struct wmm_tspec_element *)
134 m->u.action.u.wmm_action.variable;
135 int len;
136
137 hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211,
138 HOSTAPD_LEVEL_DEBUG,
139 "action response - reason %d", status_code);
140 os_memset(buf, 0, sizeof(buf));
141 m->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
142 WLAN_FC_STYPE_ACTION);
143 os_memcpy(m->da, addr, ETH_ALEN);
144 os_memcpy(m->sa, hapd->own_addr, ETH_ALEN);
145 os_memcpy(m->bssid, hapd->own_addr, ETH_ALEN);
146 m->u.action.category = WLAN_ACTION_WMM;
147 m->u.action.u.wmm_action.action_code = action_code;
148 m->u.action.u.wmm_action.dialog_token = dialogue_token;
149 m->u.action.u.wmm_action.status_code = status_code;
150 os_memcpy(t, tspec, sizeof(struct wmm_tspec_element));
151 len = ((u8 *) (t + 1)) - buf;
152
153 if (hostapd_drv_send_mlme(hapd, m, len, 0) < 0)
154 wpa_printf(MSG_INFO, "wmm_send_action: send failed");
155 }
156
157
wmm_process_tspec(struct wmm_tspec_element * tspec)158 int wmm_process_tspec(struct wmm_tspec_element *tspec)
159 {
160 int medium_time, pps, duration;
161 int up, psb, dir, tid;
162 u16 val, surplus;
163
164 up = (tspec->ts_info[1] >> 3) & 0x07;
165 psb = (tspec->ts_info[1] >> 2) & 0x01;
166 dir = (tspec->ts_info[0] >> 5) & 0x03;
167 tid = (tspec->ts_info[0] >> 1) & 0x0f;
168 wpa_printf(MSG_DEBUG, "WMM: TS Info: UP=%d PSB=%d Direction=%d TID=%d",
169 up, psb, dir, tid);
170 val = le_to_host16(tspec->nominal_msdu_size);
171 wpa_printf(MSG_DEBUG, "WMM: Nominal MSDU Size: %d%s",
172 val & 0x7fff, val & 0x8000 ? " (fixed)" : "");
173 wpa_printf(MSG_DEBUG, "WMM: Mean Data Rate: %u bps",
174 le_to_host32(tspec->mean_data_rate));
175 wpa_printf(MSG_DEBUG, "WMM: Minimum PHY Rate: %u bps",
176 le_to_host32(tspec->minimum_phy_rate));
177 val = le_to_host16(tspec->surplus_bandwidth_allowance);
178 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance: %u.%04u",
179 val >> 13, 10000 * (val & 0x1fff) / 0x2000);
180
181 val = le_to_host16(tspec->nominal_msdu_size);
182 if (val == 0) {
183 wpa_printf(MSG_DEBUG, "WMM: Invalid Nominal MSDU Size (0)");
184 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
185 }
186 /* pps = Ceiling((Mean Data Rate / 8) / Nominal MSDU Size) */
187 pps = ((le_to_host32(tspec->mean_data_rate) / 8) + val - 1) / val;
188 wpa_printf(MSG_DEBUG, "WMM: Packets-per-second estimate for TSPEC: %d",
189 pps);
190
191 if (le_to_host32(tspec->minimum_phy_rate) < 1000000) {
192 wpa_printf(MSG_DEBUG, "WMM: Too small Minimum PHY Rate");
193 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
194 }
195
196 duration = (le_to_host16(tspec->nominal_msdu_size) & 0x7fff) * 8 /
197 (le_to_host32(tspec->minimum_phy_rate) / 1000000) +
198 50 /* FIX: proper SIFS + ACK duration */;
199
200 /* unsigned binary number with an implicit binary point after the
201 * leftmost 3 bits, i.e., 0x2000 = 1.0 */
202 surplus = le_to_host16(tspec->surplus_bandwidth_allowance);
203 if (surplus <= 0x2000) {
204 wpa_printf(MSG_DEBUG, "WMM: Surplus Bandwidth Allowance not "
205 "greater than unity");
206 return WMM_ADDTS_STATUS_INVALID_PARAMETERS;
207 }
208
209 medium_time = surplus * pps * duration / 0x2000;
210 wpa_printf(MSG_DEBUG, "WMM: Estimated medium time: %u", medium_time);
211
212 /*
213 * TODO: store list of granted (and still active) TSPECs and check
214 * whether there is available medium time for this request. For now,
215 * just refuse requests that would by themselves take very large
216 * portion of the available bandwidth.
217 */
218 if (medium_time > 750000) {
219 wpa_printf(MSG_DEBUG, "WMM: Refuse TSPEC request for over "
220 "75%% of available bandwidth");
221 return WMM_ADDTS_STATUS_REFUSED;
222 }
223
224 /* Convert to 32 microseconds per second unit */
225 tspec->medium_time = host_to_le16(medium_time / 32);
226
227 return WMM_ADDTS_STATUS_ADMISSION_ACCEPTED;
228 }
229
230
wmm_addts_req(struct hostapd_data * hapd,const struct ieee80211_mgmt * mgmt,struct wmm_tspec_element * tspec,size_t len)231 static void wmm_addts_req(struct hostapd_data *hapd,
232 const struct ieee80211_mgmt *mgmt,
233 struct wmm_tspec_element *tspec, size_t len)
234 {
235 const u8 *end = ((const u8 *) mgmt) + len;
236 int res;
237
238 if ((const u8 *) (tspec + 1) > end) {
239 wpa_printf(MSG_DEBUG, "WMM: TSPEC overflow in ADDTS Request");
240 return;
241 }
242
243 wpa_printf(MSG_DEBUG, "WMM: ADDTS Request (Dialog Token %d) for TSPEC "
244 "from " MACSTR,
245 mgmt->u.action.u.wmm_action.dialog_token,
246 MAC2STR(mgmt->sa));
247
248 res = wmm_process_tspec(tspec);
249 wpa_printf(MSG_DEBUG, "WMM: ADDTS processing result: %d", res);
250
251 wmm_send_action(hapd, mgmt->sa, tspec, WMM_ACTION_CODE_ADDTS_RESP,
252 mgmt->u.action.u.wmm_action.dialog_token, res);
253 }
254
255
hostapd_wmm_action(struct hostapd_data * hapd,const struct ieee80211_mgmt * mgmt,size_t len)256 void hostapd_wmm_action(struct hostapd_data *hapd,
257 const struct ieee80211_mgmt *mgmt, size_t len)
258 {
259 int action_code;
260 int left = len - IEEE80211_HDRLEN - 4;
261 const u8 *pos = ((const u8 *) mgmt) + IEEE80211_HDRLEN + 4;
262 struct ieee802_11_elems elems;
263 struct sta_info *sta = ap_get_sta(hapd, mgmt->sa);
264
265 /* check that the request comes from a valid station */
266 if (!sta ||
267 (sta->flags & (WLAN_STA_ASSOC | WLAN_STA_WMM)) !=
268 (WLAN_STA_ASSOC | WLAN_STA_WMM)) {
269 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
270 HOSTAPD_LEVEL_DEBUG,
271 "wmm action received is not from associated wmm"
272 " station");
273 /* TODO: respond with action frame refused status code */
274 return;
275 }
276
277 if (left < 0)
278 return; /* not a valid WMM Action frame */
279
280 /* extract the tspec info element */
281 if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) {
282 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
283 HOSTAPD_LEVEL_DEBUG,
284 "hostapd_wmm_action - could not parse wmm "
285 "action");
286 /* TODO: respond with action frame invalid parameters status
287 * code */
288 return;
289 }
290
291 if (!elems.wmm_tspec ||
292 elems.wmm_tspec_len != (sizeof(struct wmm_tspec_element) - 2)) {
293 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
294 HOSTAPD_LEVEL_DEBUG,
295 "hostapd_wmm_action - missing or wrong length "
296 "tspec");
297 /* TODO: respond with action frame invalid parameters status
298 * code */
299 return;
300 }
301
302 /* TODO: check the request is for an AC with ACM set, if not, refuse
303 * request */
304
305 action_code = mgmt->u.action.u.wmm_action.action_code;
306 switch (action_code) {
307 case WMM_ACTION_CODE_ADDTS_REQ:
308 wmm_addts_req(hapd, mgmt, (struct wmm_tspec_element *)
309 (elems.wmm_tspec - 2), len);
310 return;
311 #if 0
312 /* TODO: needed for client implementation */
313 case WMM_ACTION_CODE_ADDTS_RESP:
314 wmm_setup_request(hapd, mgmt, len);
315 return;
316 /* TODO: handle station teardown requests */
317 case WMM_ACTION_CODE_DELTS:
318 wmm_teardown(hapd, mgmt, len);
319 return;
320 #endif
321 }
322
323 hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
324 HOSTAPD_LEVEL_DEBUG,
325 "hostapd_wmm_action - unknown action code %d",
326 action_code);
327 }
328