xref: /openbmc/linux/net/wireless/mesh.c (revision 711aab1d)
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 	int err;
103 
104 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
105 
106 	ASSERT_WDEV_LOCK(wdev);
107 
108 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
109 		return -EOPNOTSUPP;
110 
111 	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
112 	      setup->is_secure)
113 		return -EOPNOTSUPP;
114 
115 	if (wdev->mesh_id_len)
116 		return -EALREADY;
117 
118 	if (!setup->mesh_id_len)
119 		return -EINVAL;
120 
121 	if (!rdev->ops->join_mesh)
122 		return -EOPNOTSUPP;
123 
124 	if (!setup->chandef.chan) {
125 		/* if no channel explicitly given, use preset channel */
126 		setup->chandef = wdev->preset_chandef;
127 	}
128 
129 	if (!setup->chandef.chan) {
130 		/* if we don't have that either, use the first usable channel */
131 		enum nl80211_band band;
132 
133 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
134 			struct ieee80211_supported_band *sband;
135 			struct ieee80211_channel *chan;
136 			int i;
137 
138 			sband = rdev->wiphy.bands[band];
139 			if (!sband)
140 				continue;
141 
142 			for (i = 0; i < sband->n_channels; i++) {
143 				chan = &sband->channels[i];
144 				if (chan->flags & (IEEE80211_CHAN_NO_IR |
145 						   IEEE80211_CHAN_DISABLED |
146 						   IEEE80211_CHAN_RADAR))
147 					continue;
148 				setup->chandef.chan = chan;
149 				break;
150 			}
151 
152 			if (setup->chandef.chan)
153 				break;
154 		}
155 
156 		/* no usable channel ... */
157 		if (!setup->chandef.chan)
158 			return -EINVAL;
159 
160 		setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
161 		setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
162 	}
163 
164 	/*
165 	 * check if basic rates are available otherwise use mandatory rates as
166 	 * basic rates
167 	 */
168 	if (!setup->basic_rates) {
169 		enum nl80211_bss_scan_width scan_width;
170 		struct ieee80211_supported_band *sband =
171 				rdev->wiphy.bands[setup->chandef.chan->band];
172 		scan_width = cfg80211_chandef_to_scan_width(&setup->chandef);
173 		setup->basic_rates = ieee80211_mandatory_rates(sband,
174 							       scan_width);
175 	}
176 
177 	err = cfg80211_chandef_dfs_required(&rdev->wiphy,
178 					    &setup->chandef,
179 					    NL80211_IFTYPE_MESH_POINT);
180 	if (err < 0)
181 		return err;
182 	if (err > 0 && !setup->userspace_handles_dfs)
183 		return -EINVAL;
184 
185 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef,
186 				     NL80211_IFTYPE_MESH_POINT))
187 		return -EINVAL;
188 
189 	err = rdev_join_mesh(rdev, dev, conf, setup);
190 	if (!err) {
191 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
192 		wdev->mesh_id_len = setup->mesh_id_len;
193 		wdev->chandef = setup->chandef;
194 		wdev->beacon_interval = setup->beacon_interval;
195 	}
196 
197 	return err;
198 }
199 
200 int cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
201 		       struct net_device *dev,
202 		       struct mesh_setup *setup,
203 		       const struct mesh_config *conf)
204 {
205 	struct wireless_dev *wdev = dev->ieee80211_ptr;
206 	int err;
207 
208 	wdev_lock(wdev);
209 	err = __cfg80211_join_mesh(rdev, dev, setup, conf);
210 	wdev_unlock(wdev);
211 
212 	return err;
213 }
214 
215 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
216 			      struct wireless_dev *wdev,
217 			      struct cfg80211_chan_def *chandef)
218 {
219 	int err;
220 
221 	/*
222 	 * Workaround for libertas (only!), it puts the interface
223 	 * into mesh mode but doesn't implement join_mesh. Instead,
224 	 * it is configured via sysfs and then joins the mesh when
225 	 * you set the channel. Note that the libertas mesh isn't
226 	 * compatible with 802.11 mesh.
227 	 */
228 	if (rdev->ops->libertas_set_mesh_channel) {
229 		if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
230 			return -EINVAL;
231 
232 		if (!netif_running(wdev->netdev))
233 			return -ENETDOWN;
234 
235 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
236 						     chandef->chan);
237 		if (!err)
238 			wdev->chandef = *chandef;
239 
240 		return err;
241 	}
242 
243 	if (wdev->mesh_id_len)
244 		return -EBUSY;
245 
246 	wdev->preset_chandef = *chandef;
247 	return 0;
248 }
249 
250 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->beacon_interval = 0;
271 		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
272 		rdev_set_qos_map(rdev, dev, NULL);
273 		cfg80211_sched_dfs_chan_update(rdev);
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