1 /*
2  * hostapd - MBO
3  * Copyright (c) 2016, Qualcomm Atheros, Inc.
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  */
8 
9 #include "utils/includes.h"
10 
11 #include "utils/common.h"
12 #include "common/ieee802_11_defs.h"
13 #include "common/ieee802_11_common.h"
14 #include "hostapd.h"
15 #include "sta_info.h"
16 #include "mbo_ap.h"
17 
18 
19 void mbo_ap_sta_free(struct sta_info *sta)
20 {
21 	struct mbo_non_pref_chan_info *info, *prev;
22 
23 	info = sta->non_pref_chan;
24 	sta->non_pref_chan = NULL;
25 	while (info) {
26 		prev = info;
27 		info = info->next;
28 		os_free(prev);
29 	}
30 }
31 
32 
33 static void mbo_ap_parse_non_pref_chan(struct sta_info *sta,
34 				       const u8 *buf, size_t len)
35 {
36 	struct mbo_non_pref_chan_info *info, *tmp;
37 	char channels[200], *pos, *end;
38 	size_t num_chan, i;
39 	int ret;
40 
41 	if (len <= 3)
42 		return; /* Not enough room for any channels */
43 
44 	num_chan = len - 3;
45 	info = os_zalloc(sizeof(*info) + num_chan);
46 	if (!info)
47 		return;
48 	info->op_class = buf[0];
49 	info->pref = buf[len - 2];
50 	info->reason_code = buf[len - 1];
51 	info->num_channels = num_chan;
52 	buf++;
53 	os_memcpy(info->channels, buf, num_chan);
54 	if (!sta->non_pref_chan) {
55 		sta->non_pref_chan = info;
56 	} else {
57 		tmp = sta->non_pref_chan;
58 		while (tmp->next)
59 			tmp = tmp->next;
60 		tmp->next = info;
61 	}
62 
63 	pos = channels;
64 	end = pos + sizeof(channels);
65 	*pos = '\0';
66 	for (i = 0; i < num_chan; i++) {
67 		ret = os_snprintf(pos, end - pos, "%s%u",
68 				  i == 0 ? "" : " ", buf[i]);
69 		if (os_snprintf_error(end - pos, ret)) {
70 			*pos = '\0';
71 			break;
72 		}
73 		pos += ret;
74 	}
75 
76 	wpa_printf(MSG_DEBUG, "MBO: STA " MACSTR
77 		   " non-preferred channel list (op class %u, pref %u, reason code %u, channels %s)",
78 		   MAC2STR(sta->addr), info->op_class, info->pref,
79 		   info->reason_code, channels);
80 }
81 
82 
83 void mbo_ap_check_sta_assoc(struct hostapd_data *hapd, struct sta_info *sta,
84 			    struct ieee802_11_elems *elems)
85 {
86 	const u8 *pos, *attr, *end;
87 	size_t len;
88 
89 	if (!hapd->conf->mbo_enabled || !elems->mbo)
90 		return;
91 
92 	pos = elems->mbo + 4;
93 	len = elems->mbo_len - 4;
94 	wpa_hexdump(MSG_DEBUG, "MBO: Association Request attributes", pos, len);
95 
96 	attr = get_ie(pos, len, MBO_ATTR_ID_CELL_DATA_CAPA);
97 	if (attr && attr[1] >= 1)
98 		sta->cell_capa = attr[2];
99 
100 	mbo_ap_sta_free(sta);
101 	end = pos + len;
102 	while (end - pos > 1) {
103 		u8 ie_len = pos[1];
104 
105 		if (2 + ie_len > end - pos)
106 			break;
107 
108 		if (pos[0] == MBO_ATTR_ID_NON_PREF_CHAN_REPORT)
109 			mbo_ap_parse_non_pref_chan(sta, pos + 2, ie_len);
110 		pos += 2 + pos[1];
111 	}
112 }
113 
114 
115 int mbo_ap_get_info(struct sta_info *sta, char *buf, size_t buflen)
116 {
117 	char *pos = buf, *end = buf + buflen;
118 	int ret;
119 	struct mbo_non_pref_chan_info *info;
120 	u8 i;
121 	unsigned int count = 0;
122 
123 	if (!sta->cell_capa)
124 		return 0;
125 
126 	ret = os_snprintf(pos, end - pos, "mbo_cell_capa=%u\n", sta->cell_capa);
127 	if (os_snprintf_error(end - pos, ret))
128 		return pos - buf;
129 	pos += ret;
130 
131 	for (info = sta->non_pref_chan; info; info = info->next) {
132 		char *pos2 = pos;
133 
134 		ret = os_snprintf(pos2, end - pos2,
135 				  "non_pref_chan[%u]=%u:%u:%u:",
136 				  count, info->op_class, info->pref,
137 				  info->reason_code);
138 		count++;
139 		if (os_snprintf_error(end - pos2, ret))
140 			break;
141 		pos2 += ret;
142 
143 		for (i = 0; i < info->num_channels; i++) {
144 			ret = os_snprintf(pos2, end - pos2, "%u%s",
145 					  info->channels[i],
146 					  i + 1 < info->num_channels ?
147 					  "," : "");
148 			if (os_snprintf_error(end - pos2, ret)) {
149 				pos2 = NULL;
150 				break;
151 			}
152 			pos2 += ret;
153 		}
154 
155 		if (!pos2)
156 			break;
157 		ret = os_snprintf(pos2, end - pos2, "\n");
158 		if (os_snprintf_error(end - pos2, ret))
159 			break;
160 		pos2 += ret;
161 		pos = pos2;
162 	}
163 
164 	return pos - buf;
165 }
166 
167 
168 static void mbo_ap_wnm_notif_req_cell_capa(struct sta_info *sta,
169 					   const u8 *buf, size_t len)
170 {
171 	if (len < 1)
172 		return;
173 	wpa_printf(MSG_DEBUG, "MBO: STA " MACSTR
174 		   " updated cellular data capability: %u",
175 		   MAC2STR(sta->addr), buf[0]);
176 	sta->cell_capa = buf[0];
177 }
178 
179 
180 static void mbo_ap_wnm_notif_req_elem(struct sta_info *sta, u8 type,
181 				      const u8 *buf, size_t len,
182 				      int *first_non_pref_chan)
183 {
184 	switch (type) {
185 	case WFA_WNM_NOTIF_SUBELEM_NON_PREF_CHAN_REPORT:
186 		if (*first_non_pref_chan) {
187 			/*
188 			 * Need to free the previously stored entries now to
189 			 * allow the update to replace all entries.
190 			 */
191 			*first_non_pref_chan = 0;
192 			mbo_ap_sta_free(sta);
193 		}
194 		mbo_ap_parse_non_pref_chan(sta, buf, len);
195 		break;
196 	case WFA_WNM_NOTIF_SUBELEM_CELL_DATA_CAPA:
197 		mbo_ap_wnm_notif_req_cell_capa(sta, buf, len);
198 		break;
199 	default:
200 		wpa_printf(MSG_DEBUG,
201 			   "MBO: Ignore unknown WNM Notification WFA subelement %u",
202 			   type);
203 		break;
204 	}
205 }
206 
207 
208 void mbo_ap_wnm_notification_req(struct hostapd_data *hapd, const u8 *addr,
209 				 const u8 *buf, size_t len)
210 {
211 	const u8 *pos, *end;
212 	u8 ie_len;
213 	struct sta_info *sta;
214 	int first_non_pref_chan = 1;
215 
216 	if (!hapd->conf->mbo_enabled)
217 		return;
218 
219 	sta = ap_get_sta(hapd, addr);
220 	if (!sta)
221 		return;
222 
223 	pos = buf;
224 	end = buf + len;
225 
226 	while (end - pos > 1) {
227 		ie_len = pos[1];
228 
229 		if (2 + ie_len > end - pos)
230 			break;
231 
232 		if (pos[0] == WLAN_EID_VENDOR_SPECIFIC &&
233 		    ie_len >= 4 && WPA_GET_BE24(pos + 2) == OUI_WFA)
234 			mbo_ap_wnm_notif_req_elem(sta, pos[5],
235 						  pos + 6, ie_len - 4,
236 						  &first_non_pref_chan);
237 		else
238 			wpa_printf(MSG_DEBUG,
239 				   "MBO: Ignore unknown WNM Notification element %u (len=%u)",
240 				   pos[0], pos[1]);
241 
242 		pos += 2 + pos[1];
243 	}
244 }
245