xref: /openbmc/linux/net/wireless/mesh.c (revision 840ef8b7cc584a23c4f9d05352f4dbaf8e56e5ab)
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 #define MESH_DEFAULT_BEACON_INTERVAL	1000	/* in 1024 us units (=TUs) */
48 #define MESH_DEFAULT_DTIM_PERIOD	2
49 #define MESH_DEFAULT_AWAKE_WINDOW	10	/* in 1024 us units (=TUs) */
50 
51 const struct mesh_config default_mesh_config = {
52 	.dot11MeshRetryTimeout = MESH_RET_T,
53 	.dot11MeshConfirmTimeout = MESH_CONF_T,
54 	.dot11MeshHoldingTimeout = MESH_HOLD_T,
55 	.dot11MeshMaxRetries = MESH_MAX_RETR,
56 	.dot11MeshTTL = MESH_TTL,
57 	.element_ttl = MESH_DEFAULT_ELEMENT_TTL,
58 	.auto_open_plinks = true,
59 	.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
60 	.dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
61 	.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
62 	.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
63 	.dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
64 	.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
65 	.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
66 	.path_refresh_time = MESH_PATH_REFRESH_TIME,
67 	.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
68 	.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
69 	.dot11MeshGateAnnouncementProtocol = false,
70 	.dot11MeshForwarding = true,
71 	.rssi_threshold = MESH_RSSI_THRESHOLD,
72 	.ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
73 	.dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
74 	.dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
75 	.dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
76 	.power_mode = NL80211_MESH_POWER_ACTIVE,
77 	.dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
78 };
79 
80 const struct mesh_setup default_mesh_setup = {
81 	/* cfg80211_join_mesh() will pick a channel if needed */
82 	.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
83 	.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
84 	.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
85 	.ie = NULL,
86 	.ie_len = 0,
87 	.is_secure = false,
88 	.beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
89 	.dtim_period = MESH_DEFAULT_DTIM_PERIOD,
90 };
91 
92 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
93 			 struct net_device *dev,
94 			 struct mesh_setup *setup,
95 			 const struct mesh_config *conf)
96 {
97 	struct wireless_dev *wdev = dev->ieee80211_ptr;
98 	int err;
99 
100 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
101 
102 	ASSERT_WDEV_LOCK(wdev);
103 
104 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
105 		return -EOPNOTSUPP;
106 
107 	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
108 	      setup->is_secure)
109 		return -EOPNOTSUPP;
110 
111 	if (wdev->mesh_id_len)
112 		return -EALREADY;
113 
114 	if (!setup->mesh_id_len)
115 		return -EINVAL;
116 
117 	if (!rdev->ops->join_mesh)
118 		return -EOPNOTSUPP;
119 
120 	if (!setup->chandef.chan) {
121 		/* if no channel explicitly given, use preset channel */
122 		setup->chandef = wdev->preset_chandef;
123 	}
124 
125 	if (!setup->chandef.chan) {
126 		/* if we don't have that either, use the first usable channel */
127 		enum ieee80211_band band;
128 
129 		for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
130 			struct ieee80211_supported_band *sband;
131 			struct ieee80211_channel *chan;
132 			int i;
133 
134 			sband = rdev->wiphy.bands[band];
135 			if (!sband)
136 				continue;
137 
138 			for (i = 0; i < sband->n_channels; i++) {
139 				chan = &sband->channels[i];
140 				if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
141 						   IEEE80211_CHAN_PASSIVE_SCAN |
142 						   IEEE80211_CHAN_DISABLED |
143 						   IEEE80211_CHAN_RADAR))
144 					continue;
145 				setup->chandef.chan = chan;
146 				break;
147 			}
148 
149 			if (setup->chandef.chan)
150 				break;
151 		}
152 
153 		/* no usable channel ... */
154 		if (!setup->chandef.chan)
155 			return -EINVAL;
156 
157 		setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
158 		setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
159 	}
160 
161 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef))
162 		return -EINVAL;
163 
164 	err = cfg80211_can_use_chan(rdev, wdev, setup->chandef.chan,
165 				    CHAN_MODE_SHARED);
166 	if (err)
167 		return err;
168 
169 	err = rdev_join_mesh(rdev, dev, conf, setup);
170 	if (!err) {
171 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
172 		wdev->mesh_id_len = setup->mesh_id_len;
173 		wdev->channel = setup->chandef.chan;
174 	}
175 
176 	return err;
177 }
178 
179 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
180 		       struct net_device *dev,
181 		       struct mesh_setup *setup,
182 		       const struct mesh_config *conf)
183 {
184 	struct wireless_dev *wdev = dev->ieee80211_ptr;
185 	int err;
186 
187 	mutex_lock(&rdev->devlist_mtx);
188 	wdev_lock(wdev);
189 	err = __cfg80211_join_mesh(rdev, dev, setup, conf);
190 	wdev_unlock(wdev);
191 	mutex_unlock(&rdev->devlist_mtx);
192 
193 	return err;
194 }
195 
196 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
197 			      struct wireless_dev *wdev,
198 			      struct cfg80211_chan_def *chandef)
199 {
200 	int err;
201 
202 	/*
203 	 * Workaround for libertas (only!), it puts the interface
204 	 * into mesh mode but doesn't implement join_mesh. Instead,
205 	 * it is configured via sysfs and then joins the mesh when
206 	 * you set the channel. Note that the libertas mesh isn't
207 	 * compatible with 802.11 mesh.
208 	 */
209 	if (rdev->ops->libertas_set_mesh_channel) {
210 		if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
211 			return -EINVAL;
212 
213 		if (!netif_running(wdev->netdev))
214 			return -ENETDOWN;
215 
216 		err = cfg80211_can_use_chan(rdev, wdev, chandef->chan,
217 					    CHAN_MODE_SHARED);
218 		if (err)
219 			return err;
220 
221 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
222 						     chandef->chan);
223 		if (!err)
224 			wdev->channel = chandef->chan;
225 
226 		return err;
227 	}
228 
229 	if (wdev->mesh_id_len)
230 		return -EBUSY;
231 
232 	wdev->preset_chandef = *chandef;
233 	return 0;
234 }
235 
236 void cfg80211_notify_new_peer_candidate(struct net_device *dev,
237 		const u8 *macaddr, const u8* ie, u8 ie_len, gfp_t gfp)
238 {
239 	struct wireless_dev *wdev = dev->ieee80211_ptr;
240 
241 	trace_cfg80211_notify_new_peer_candidate(dev, macaddr);
242 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_MESH_POINT))
243 		return;
244 
245 	nl80211_send_new_peer_candidate(wiphy_to_dev(wdev->wiphy), dev,
246 			macaddr, ie, ie_len, gfp);
247 }
248 EXPORT_SYMBOL(cfg80211_notify_new_peer_candidate);
249 
250 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
251 				 struct net_device *dev)
252 {
253 	struct wireless_dev *wdev = dev->ieee80211_ptr;
254 	int err;
255 
256 	ASSERT_WDEV_LOCK(wdev);
257 
258 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
259 		return -EOPNOTSUPP;
260 
261 	if (!rdev->ops->leave_mesh)
262 		return -EOPNOTSUPP;
263 
264 	if (!wdev->mesh_id_len)
265 		return -ENOTCONN;
266 
267 	err = rdev_leave_mesh(rdev, dev);
268 	if (!err) {
269 		wdev->mesh_id_len = 0;
270 		wdev->channel = NULL;
271 	}
272 
273 	return err;
274 }
275 
276 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
277 			struct net_device *dev)
278 {
279 	struct wireless_dev *wdev = dev->ieee80211_ptr;
280 	int err;
281 
282 	wdev_lock(wdev);
283 	err = __cfg80211_leave_mesh(rdev, dev);
284 	wdev_unlock(wdev);
285 
286 	return err;
287 }
288