xref: /linux/net/wireless/mesh.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 
22 /*
23  * Minimum interval between two consecutive PREQs originated by the same
24  * interface
25  */
26 #define MESH_PREQ_MIN_INT	10
27 #define MESH_PERR_MIN_INT	100
28 #define MESH_DIAM_TRAVERSAL_TIME 50
29 
30 #define MESH_RSSI_THRESHOLD	0
31 
32 /*
33  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
34  * before timing out.  This way it will remain ACTIVE and no data frames
35  * will be unnecessarily held in the pending queue.
36  */
37 #define MESH_PATH_REFRESH_TIME			1000
38 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
39 
40 /* Default maximum number of established plinks per interface */
41 #define MESH_MAX_ESTAB_PLINKS	32
42 
43 #define MESH_MAX_PREQ_RETRIES	4
44 
45 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
46 
47 const struct mesh_config default_mesh_config = {
48 	.dot11MeshRetryTimeout = MESH_RET_T,
49 	.dot11MeshConfirmTimeout = MESH_CONF_T,
50 	.dot11MeshHoldingTimeout = MESH_HOLD_T,
51 	.dot11MeshMaxRetries = MESH_MAX_RETR,
52 	.dot11MeshTTL = MESH_TTL,
53 	.element_ttl = MESH_DEFAULT_ELEMENT_TTL,
54 	.auto_open_plinks = true,
55 	.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
56 	.dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
57 	.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
58 	.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
59 	.dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
60 	.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
61 	.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
62 	.path_refresh_time = MESH_PATH_REFRESH_TIME,
63 	.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
64 	.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
65 	.dot11MeshGateAnnouncementProtocol = false,
66 	.dot11MeshForwarding = true,
67 	.rssi_threshold = MESH_RSSI_THRESHOLD,
68 	.ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
69 	.dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
70 	.dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
71 	.dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
72 };
73 
74 const struct mesh_setup default_mesh_setup = {
75 	/* cfg80211_join_mesh() will pick a channel if needed */
76 	.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
77 	.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
78 	.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
79 	.ie = NULL,
80 	.ie_len = 0,
81 	.is_secure = false,
82 };
83 
84 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
85 			 struct net_device *dev,
86 			 struct mesh_setup *setup,
87 			 const struct mesh_config *conf)
88 {
89 	struct wireless_dev *wdev = dev->ieee80211_ptr;
90 	int err;
91 
92 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
93 
94 	ASSERT_WDEV_LOCK(wdev);
95 
96 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
97 		return -EOPNOTSUPP;
98 
99 	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
100 	      setup->is_secure)
101 		return -EOPNOTSUPP;
102 
103 	if (wdev->mesh_id_len)
104 		return -EALREADY;
105 
106 	if (!setup->mesh_id_len)
107 		return -EINVAL;
108 
109 	if (!rdev->ops->join_mesh)
110 		return -EOPNOTSUPP;
111 
112 	if (!setup->chandef.chan) {
113 		/* if no channel explicitly given, use preset channel */
114 		setup->chandef = wdev->preset_chandef;
115 	}
116 
117 	if (!setup->chandef.chan) {
118 		/* if we don't have that either, use the first usable channel */
119 		enum ieee80211_band band;
120 
121 		for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
122 			struct ieee80211_supported_band *sband;
123 			struct ieee80211_channel *chan;
124 			int i;
125 
126 			sband = rdev->wiphy.bands[band];
127 			if (!sband)
128 				continue;
129 
130 			for (i = 0; i < sband->n_channels; i++) {
131 				chan = &sband->channels[i];
132 				if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
133 						   IEEE80211_CHAN_PASSIVE_SCAN |
134 						   IEEE80211_CHAN_DISABLED |
135 						   IEEE80211_CHAN_RADAR))
136 					continue;
137 				setup->chandef.chan = chan;
138 				break;
139 			}
140 
141 			if (setup->chandef.chan)
142 				break;
143 		}
144 
145 		/* no usable channel ... */
146 		if (!setup->chandef.chan)
147 			return -EINVAL;
148 
149 		setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
150 		setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
151 	}
152 
153 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef))
154 		return -EINVAL;
155 
156 	err = cfg80211_can_use_chan(rdev, wdev, setup->chandef.chan,
157 				    CHAN_MODE_SHARED);
158 	if (err)
159 		return err;
160 
161 	err = rdev_join_mesh(rdev, dev, conf, setup);
162 	if (!err) {
163 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
164 		wdev->mesh_id_len = setup->mesh_id_len;
165 		wdev->channel = setup->chandef.chan;
166 	}
167 
168 	return err;
169 }
170 
171 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
172 		       struct net_device *dev,
173 		       struct mesh_setup *setup,
174 		       const struct mesh_config *conf)
175 {
176 	struct wireless_dev *wdev = dev->ieee80211_ptr;
177 	int err;
178 
179 	mutex_lock(&rdev->devlist_mtx);
180 	wdev_lock(wdev);
181 	err = __cfg80211_join_mesh(rdev, dev, setup, conf);
182 	wdev_unlock(wdev);
183 	mutex_unlock(&rdev->devlist_mtx);
184 
185 	return err;
186 }
187 
188 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
189 			      struct wireless_dev *wdev,
190 			      struct cfg80211_chan_def *chandef)
191 {
192 	int err;
193 
194 	/*
195 	 * Workaround for libertas (only!), it puts the interface
196 	 * into mesh mode but doesn't implement join_mesh. Instead,
197 	 * it is configured via sysfs and then joins the mesh when
198 	 * you set the channel. Note that the libertas mesh isn't
199 	 * compatible with 802.11 mesh.
200 	 */
201 	if (rdev->ops->libertas_set_mesh_channel) {
202 		if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
203 			return -EINVAL;
204 
205 		if (!netif_running(wdev->netdev))
206 			return -ENETDOWN;
207 
208 		err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
209 					    CHAN_MODE_SHARED);
210 		if (err)
211 			return err;
212 
213 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
214 						     chandef->chan);
215 		if (!err)
216 			wdev->channel = chandef->chan;
217 
218 		return err;
219 	}
220 
221 	if (wdev->mesh_id_len)
222 		return -EBUSY;
223 
224 	wdev->preset_chandef = *chandef;
225 	return 0;
226 }
227 
228 void cfg80211_notify_new_peer_candidate(struct net_device *dev,
229 		const u8 *macaddr, const u8* ie, u8 ie_len, gfp_t gfp)
230 {
231 	struct wireless_dev *wdev = dev->ieee80211_ptr;
232 
233 	trace_cfg80211_notify_new_peer_candidate(dev, macaddr);
234 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_MESH_POINT))
235 		return;
236 
237 	nl80211_send_new_peer_candidate(wiphy_to_dev(wdev->wiphy), dev,
238 			macaddr, ie, ie_len, gfp);
239 }
240 EXPORT_SYMBOL(cfg80211_notify_new_peer_candidate);
241 
242 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
243 				 struct net_device *dev)
244 {
245 	struct wireless_dev *wdev = dev->ieee80211_ptr;
246 	int err;
247 
248 	ASSERT_WDEV_LOCK(wdev);
249 
250 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
251 		return -EOPNOTSUPP;
252 
253 	if (!rdev->ops->leave_mesh)
254 		return -EOPNOTSUPP;
255 
256 	if (!wdev->mesh_id_len)
257 		return -ENOTCONN;
258 
259 	err = rdev_leave_mesh(rdev, dev);
260 	if (!err) {
261 		wdev->mesh_id_len = 0;
262 		wdev->channel = NULL;
263 	}
264 
265 	return err;
266 }
267 
268 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
269 			struct net_device *dev)
270 {
271 	struct wireless_dev *wdev = dev->ieee80211_ptr;
272 	int err;
273 
274 	wdev_lock(wdev);
275 	err = __cfg80211_leave_mesh(rdev, dev);
276 	wdev_unlock(wdev);
277 
278 	return err;
279 }
280