xref: /linux/net/wireless/mesh.c (revision c5aec4c76af1a2d89ee2f2d4d5463b2ad2d85de5)
1 #include <linux/ieee80211.h>
2 #include <linux/export.h>
3 #include <net/cfg80211.h>
4 #include "nl80211.h"
5 #include "core.h"
6 #include "rdev-ops.h"
7 
8 /* Default values, timeouts in ms */
9 #define MESH_TTL 		31
10 #define MESH_DEFAULT_ELEMENT_TTL 31
11 #define MESH_MAX_RETR	 	3
12 #define MESH_RET_T 		100
13 #define MESH_CONF_T 		100
14 #define MESH_HOLD_T 		100
15 
16 #define MESH_PATH_TIMEOUT	5000
17 #define MESH_RANN_INTERVAL      5000
18 #define MESH_PATH_TO_ROOT_TIMEOUT      6000
19 #define MESH_ROOT_INTERVAL     5000
20 #define MESH_ROOT_CONFIRMATION_INTERVAL 2000
21 #define MESH_DEFAULT_PLINK_TIMEOUT	1800 /* timeout in seconds */
22 
23 /*
24  * Minimum interval between two consecutive PREQs originated by the same
25  * interface
26  */
27 #define MESH_PREQ_MIN_INT	10
28 #define MESH_PERR_MIN_INT	100
29 #define MESH_DIAM_TRAVERSAL_TIME 50
30 
31 #define MESH_RSSI_THRESHOLD	0
32 
33 /*
34  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
35  * before timing out.  This way it will remain ACTIVE and no data frames
36  * will be unnecessarily held in the pending queue.
37  */
38 #define MESH_PATH_REFRESH_TIME			1000
39 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
40 
41 /* Default maximum number of established plinks per interface */
42 #define MESH_MAX_ESTAB_PLINKS	32
43 
44 #define MESH_MAX_PREQ_RETRIES	4
45 
46 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
47 
48 #define MESH_DEFAULT_BEACON_INTERVAL	1000	/* in 1024 us units (=TUs) */
49 #define MESH_DEFAULT_DTIM_PERIOD	2
50 #define MESH_DEFAULT_AWAKE_WINDOW	10	/* in 1024 us units (=TUs) */
51 
52 const struct mesh_config default_mesh_config = {
53 	.dot11MeshRetryTimeout = MESH_RET_T,
54 	.dot11MeshConfirmTimeout = MESH_CONF_T,
55 	.dot11MeshHoldingTimeout = MESH_HOLD_T,
56 	.dot11MeshMaxRetries = MESH_MAX_RETR,
57 	.dot11MeshTTL = MESH_TTL,
58 	.element_ttl = MESH_DEFAULT_ELEMENT_TTL,
59 	.auto_open_plinks = true,
60 	.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
61 	.dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
62 	.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
63 	.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
64 	.dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
65 	.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
66 	.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
67 	.path_refresh_time = MESH_PATH_REFRESH_TIME,
68 	.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
69 	.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
70 	.dot11MeshGateAnnouncementProtocol = false,
71 	.dot11MeshForwarding = true,
72 	.rssi_threshold = MESH_RSSI_THRESHOLD,
73 	.ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
74 	.dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
75 	.dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
76 	.dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
77 	.power_mode = NL80211_MESH_POWER_ACTIVE,
78 	.dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
79 	.plink_timeout = MESH_DEFAULT_PLINK_TIMEOUT,
80 };
81 
82 const struct mesh_setup default_mesh_setup = {
83 	/* cfg80211_join_mesh() will pick a channel if needed */
84 	.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
85 	.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
86 	.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
87 	.auth_id = 0, /* open */
88 	.ie = NULL,
89 	.ie_len = 0,
90 	.is_secure = false,
91 	.user_mpm = false,
92 	.beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
93 	.dtim_period = MESH_DEFAULT_DTIM_PERIOD,
94 };
95 
96 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
97 			 struct net_device *dev,
98 			 struct mesh_setup *setup,
99 			 const struct mesh_config *conf)
100 {
101 	struct wireless_dev *wdev = dev->ieee80211_ptr;
102 	u8 radar_detect_width = 0;
103 	int err;
104 
105 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
106 
107 	ASSERT_WDEV_LOCK(wdev);
108 
109 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
110 		return -EOPNOTSUPP;
111 
112 	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
113 	      setup->is_secure)
114 		return -EOPNOTSUPP;
115 
116 	if (wdev->mesh_id_len)
117 		return -EALREADY;
118 
119 	if (!setup->mesh_id_len)
120 		return -EINVAL;
121 
122 	if (!rdev->ops->join_mesh)
123 		return -EOPNOTSUPP;
124 
125 	if (!setup->chandef.chan) {
126 		/* if no channel explicitly given, use preset channel */
127 		setup->chandef = wdev->preset_chandef;
128 	}
129 
130 	if (!setup->chandef.chan) {
131 		/* if we don't have that either, use the first usable channel */
132 		enum ieee80211_band band;
133 
134 		for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
135 			struct ieee80211_supported_band *sband;
136 			struct ieee80211_channel *chan;
137 			int i;
138 
139 			sband = rdev->wiphy.bands[band];
140 			if (!sband)
141 				continue;
142 
143 			for (i = 0; i < sband->n_channels; i++) {
144 				chan = &sband->channels[i];
145 				if (chan->flags & (IEEE80211_CHAN_NO_IR |
146 						   IEEE80211_CHAN_DISABLED |
147 						   IEEE80211_CHAN_RADAR))
148 					continue;
149 				setup->chandef.chan = chan;
150 				break;
151 			}
152 
153 			if (setup->chandef.chan)
154 				break;
155 		}
156 
157 		/* no usable channel ... */
158 		if (!setup->chandef.chan)
159 			return -EINVAL;
160 
161 		setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
162 		setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
163 	}
164 
165 	/*
166 	 * check if basic rates are available otherwise use mandatory rates as
167 	 * basic rates
168 	 */
169 	if (!setup->basic_rates) {
170 		enum nl80211_bss_scan_width scan_width;
171 		struct ieee80211_supported_band *sband =
172 				rdev->wiphy.bands[setup->chandef.chan->band];
173 		scan_width = cfg80211_chandef_to_scan_width(&setup->chandef);
174 		setup->basic_rates = ieee80211_mandatory_rates(sband,
175 							       scan_width);
176 	}
177 
178 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef))
179 		return -EINVAL;
180 
181 	err = cfg80211_chandef_dfs_required(wdev->wiphy, &setup->chandef);
182 	if (err < 0)
183 		return err;
184 	if (err)
185 		radar_detect_width = BIT(setup->chandef.width);
186 
187 	err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
188 					   setup->chandef.chan,
189 					   CHAN_MODE_SHARED,
190 					   radar_detect_width);
191 	if (err)
192 		return err;
193 
194 	err = rdev_join_mesh(rdev, dev, conf, setup);
195 	if (!err) {
196 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
197 		wdev->mesh_id_len = setup->mesh_id_len;
198 		wdev->chandef = setup->chandef;
199 	}
200 
201 	return err;
202 }
203 
204 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
205 		       struct net_device *dev,
206 		       struct mesh_setup *setup,
207 		       const struct mesh_config *conf)
208 {
209 	struct wireless_dev *wdev = dev->ieee80211_ptr;
210 	int err;
211 
212 	wdev_lock(wdev);
213 	err = __cfg80211_join_mesh(rdev, dev, setup, conf);
214 	wdev_unlock(wdev);
215 
216 	return err;
217 }
218 
219 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
220 			      struct wireless_dev *wdev,
221 			      struct cfg80211_chan_def *chandef)
222 {
223 	int err;
224 
225 	/*
226 	 * Workaround for libertas (only!), it puts the interface
227 	 * into mesh mode but doesn't implement join_mesh. Instead,
228 	 * it is configured via sysfs and then joins the mesh when
229 	 * you set the channel. Note that the libertas mesh isn't
230 	 * compatible with 802.11 mesh.
231 	 */
232 	if (rdev->ops->libertas_set_mesh_channel) {
233 		if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
234 			return -EINVAL;
235 
236 		if (!netif_running(wdev->netdev))
237 			return -ENETDOWN;
238 
239 		/* cfg80211_can_use_chan() calls
240 		 * cfg80211_can_use_iftype_chan() with no radar
241 		 * detection, so if we're trying to use a radar
242 		 * channel here, something is wrong.
243 		 */
244 		WARN_ON_ONCE(chandef->chan->flags & IEEE80211_CHAN_RADAR);
245 		err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
246 					    CHAN_MODE_SHARED);
247 		if (err)
248 			return err;
249 
250 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
251 						     chandef->chan);
252 		if (!err)
253 			wdev->chandef = *chandef;
254 
255 		return err;
256 	}
257 
258 	if (wdev->mesh_id_len)
259 		return -EBUSY;
260 
261 	wdev->preset_chandef = *chandef;
262 	return 0;
263 }
264 
265 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
266 				 struct net_device *dev)
267 {
268 	struct wireless_dev *wdev = dev->ieee80211_ptr;
269 	int err;
270 
271 	ASSERT_WDEV_LOCK(wdev);
272 
273 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
274 		return -EOPNOTSUPP;
275 
276 	if (!rdev->ops->leave_mesh)
277 		return -EOPNOTSUPP;
278 
279 	if (!wdev->mesh_id_len)
280 		return -ENOTCONN;
281 
282 	err = rdev_leave_mesh(rdev, dev);
283 	if (!err) {
284 		wdev->mesh_id_len = 0;
285 		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
286 		rdev_set_qos_map(rdev, dev, NULL);
287 	}
288 
289 	return err;
290 }
291 
292 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
293 			struct net_device *dev)
294 {
295 	struct wireless_dev *wdev = dev->ieee80211_ptr;
296 	int err;
297 
298 	wdev_lock(wdev);
299 	err = __cfg80211_leave_mesh(rdev, dev);
300 	wdev_unlock(wdev);
301 
302 	return err;
303 }
304