xref: /openbmc/linux/net/wireless/mesh.c (revision 05bcf503)
1 #include <linux/ieee80211.h>
2 #include <linux/export.h>
3 #include <net/cfg80211.h>
4 #include "nl80211.h"
5 #include "core.h"
6 
7 /* Default values, timeouts in ms */
8 #define MESH_TTL 		31
9 #define MESH_DEFAULT_ELEMENT_TTL 31
10 #define MESH_MAX_RETR	 	3
11 #define MESH_RET_T 		100
12 #define MESH_CONF_T 		100
13 #define MESH_HOLD_T 		100
14 
15 #define MESH_PATH_TIMEOUT	5000
16 #define MESH_RANN_INTERVAL      5000
17 #define MESH_PATH_TO_ROOT_TIMEOUT      6000
18 #define MESH_ROOT_INTERVAL     5000
19 #define MESH_ROOT_CONFIRMATION_INTERVAL 2000
20 
21 /*
22  * Minimum interval between two consecutive PREQs originated by the same
23  * interface
24  */
25 #define MESH_PREQ_MIN_INT	10
26 #define MESH_PERR_MIN_INT	100
27 #define MESH_DIAM_TRAVERSAL_TIME 50
28 
29 #define MESH_RSSI_THRESHOLD	0
30 
31 /*
32  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
33  * before timing out.  This way it will remain ACTIVE and no data frames
34  * will be unnecessarily held in the pending queue.
35  */
36 #define MESH_PATH_REFRESH_TIME			1000
37 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
38 
39 /* Default maximum number of established plinks per interface */
40 #define MESH_MAX_ESTAB_PLINKS	32
41 
42 #define MESH_MAX_PREQ_RETRIES	4
43 
44 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
45 
46 const struct mesh_config default_mesh_config = {
47 	.dot11MeshRetryTimeout = MESH_RET_T,
48 	.dot11MeshConfirmTimeout = MESH_CONF_T,
49 	.dot11MeshHoldingTimeout = MESH_HOLD_T,
50 	.dot11MeshMaxRetries = MESH_MAX_RETR,
51 	.dot11MeshTTL = MESH_TTL,
52 	.element_ttl = MESH_DEFAULT_ELEMENT_TTL,
53 	.auto_open_plinks = true,
54 	.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
55 	.dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
56 	.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
57 	.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
58 	.dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
59 	.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
60 	.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
61 	.path_refresh_time = MESH_PATH_REFRESH_TIME,
62 	.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
63 	.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
64 	.dot11MeshGateAnnouncementProtocol = false,
65 	.dot11MeshForwarding = true,
66 	.rssi_threshold = MESH_RSSI_THRESHOLD,
67 	.ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
68 	.dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
69 	.dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
70 	.dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
71 };
72 
73 const struct mesh_setup default_mesh_setup = {
74 	/* cfg80211_join_mesh() will pick a channel if needed */
75 	.channel = NULL,
76 	.channel_type = NL80211_CHAN_NO_HT,
77 	.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
78 	.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
79 	.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
80 	.ie = NULL,
81 	.ie_len = 0,
82 	.is_secure = false,
83 };
84 
85 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
86 			 struct net_device *dev,
87 			 struct mesh_setup *setup,
88 			 const struct mesh_config *conf)
89 {
90 	struct wireless_dev *wdev = dev->ieee80211_ptr;
91 	int err;
92 
93 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
94 
95 	ASSERT_WDEV_LOCK(wdev);
96 
97 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
98 		return -EOPNOTSUPP;
99 
100 	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
101 	      setup->is_secure)
102 		return -EOPNOTSUPP;
103 
104 	if (wdev->mesh_id_len)
105 		return -EALREADY;
106 
107 	if (!setup->mesh_id_len)
108 		return -EINVAL;
109 
110 	if (!rdev->ops->join_mesh)
111 		return -EOPNOTSUPP;
112 
113 	if (!setup->channel) {
114 		/* if no channel explicitly given, use preset channel */
115 		setup->channel = wdev->preset_chan;
116 		setup->channel_type = wdev->preset_chantype;
117 	}
118 
119 	if (!setup->channel) {
120 		/* if we don't have that either, use the first usable channel */
121 		enum ieee80211_band band;
122 
123 		for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
124 			struct ieee80211_supported_band *sband;
125 			struct ieee80211_channel *chan;
126 			int i;
127 
128 			sband = rdev->wiphy.bands[band];
129 			if (!sband)
130 				continue;
131 
132 			for (i = 0; i < sband->n_channels; i++) {
133 				chan = &sband->channels[i];
134 				if (chan->flags & (IEEE80211_CHAN_NO_IBSS |
135 						   IEEE80211_CHAN_PASSIVE_SCAN |
136 						   IEEE80211_CHAN_DISABLED |
137 						   IEEE80211_CHAN_RADAR))
138 					continue;
139 				setup->channel = chan;
140 				break;
141 			}
142 
143 			if (setup->channel)
144 				break;
145 		}
146 
147 		/* no usable channel ... */
148 		if (!setup->channel)
149 			return -EINVAL;
150 
151 		setup->channel_type = NL80211_CHAN_NO_HT;
152 	}
153 
154 	if (!cfg80211_can_beacon_sec_chan(&rdev->wiphy, setup->channel,
155 					  setup->channel_type))
156 		return -EINVAL;
157 
158 	err = cfg80211_can_use_chan(rdev, wdev, setup->channel,
159 				    CHAN_MODE_SHARED);
160 	if (err)
161 		return err;
162 
163 	err = rdev->ops->join_mesh(&rdev->wiphy, dev, conf, setup);
164 	if (!err) {
165 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
166 		wdev->mesh_id_len = setup->mesh_id_len;
167 		wdev->channel = setup->channel;
168 	}
169 
170 	return err;
171 }
172 
173 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
174 		       struct net_device *dev,
175 		       struct mesh_setup *setup,
176 		       const struct mesh_config *conf)
177 {
178 	struct wireless_dev *wdev = dev->ieee80211_ptr;
179 	int err;
180 
181 	mutex_lock(&rdev->devlist_mtx);
182 	wdev_lock(wdev);
183 	err = __cfg80211_join_mesh(rdev, dev, setup, conf);
184 	wdev_unlock(wdev);
185 	mutex_unlock(&rdev->devlist_mtx);
186 
187 	return err;
188 }
189 
190 int cfg80211_set_mesh_freq(struct cfg80211_registered_device *rdev,
191 			   struct wireless_dev *wdev, int freq,
192 			   enum nl80211_channel_type channel_type)
193 {
194 	struct ieee80211_channel *channel;
195 	int err;
196 
197 	channel = rdev_freq_to_chan(rdev, freq, channel_type);
198 	if (!channel || !cfg80211_can_beacon_sec_chan(&rdev->wiphy,
199 						      channel,
200 						      channel_type)) {
201 		return -EINVAL;
202 	}
203 
204 	/*
205 	 * Workaround for libertas (only!), it puts the interface
206 	 * into mesh mode but doesn't implement join_mesh. Instead,
207 	 * it is configured via sysfs and then joins the mesh when
208 	 * you set the channel. Note that the libertas mesh isn't
209 	 * compatible with 802.11 mesh.
210 	 */
211 	if (rdev->ops->libertas_set_mesh_channel) {
212 		if (channel_type != NL80211_CHAN_NO_HT)
213 			return -EINVAL;
214 
215 		if (!netif_running(wdev->netdev))
216 			return -ENETDOWN;
217 
218 		err = cfg80211_can_use_chan(rdev, wdev, channel,
219 					    CHAN_MODE_SHARED);
220 		if (err)
221 			return err;
222 
223 		err = rdev->ops->libertas_set_mesh_channel(&rdev->wiphy,
224 							   wdev->netdev,
225 							   channel);
226 		if (!err)
227 			wdev->channel = channel;
228 
229 		return err;
230 	}
231 
232 	if (wdev->mesh_id_len)
233 		return -EBUSY;
234 
235 	wdev->preset_chan = channel;
236 	wdev->preset_chantype = channel_type;
237 	return 0;
238 }
239 
240 void cfg80211_notify_new_peer_candidate(struct net_device *dev,
241 		const u8 *macaddr, const u8* ie, u8 ie_len, gfp_t gfp)
242 {
243 	struct wireless_dev *wdev = dev->ieee80211_ptr;
244 
245 	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_MESH_POINT))
246 		return;
247 
248 	nl80211_send_new_peer_candidate(wiphy_to_dev(wdev->wiphy), dev,
249 			macaddr, ie, ie_len, gfp);
250 }
251 EXPORT_SYMBOL(cfg80211_notify_new_peer_candidate);
252 
253 static int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
254 				 struct net_device *dev)
255 {
256 	struct wireless_dev *wdev = dev->ieee80211_ptr;
257 	int err;
258 
259 	ASSERT_WDEV_LOCK(wdev);
260 
261 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
262 		return -EOPNOTSUPP;
263 
264 	if (!rdev->ops->leave_mesh)
265 		return -EOPNOTSUPP;
266 
267 	if (!wdev->mesh_id_len)
268 		return -ENOTCONN;
269 
270 	err = rdev->ops->leave_mesh(&rdev->wiphy, dev);
271 	if (!err) {
272 		wdev->mesh_id_len = 0;
273 		wdev->channel = NULL;
274 	}
275 
276 	return err;
277 }
278 
279 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
280 			struct net_device *dev)
281 {
282 	struct wireless_dev *wdev = dev->ieee80211_ptr;
283 	int err;
284 
285 	wdev_lock(wdev);
286 	err = __cfg80211_leave_mesh(rdev, dev);
287 	wdev_unlock(wdev);
288 
289 	return err;
290 }
291