xref: /openbmc/linux/net/wireless/mesh.c (revision dbf563ee)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/ieee80211.h>
3 #include <linux/export.h>
4 #include <net/cfg80211.h>
5 #include "nl80211.h"
6 #include "core.h"
7 #include "rdev-ops.h"
8 
9 /* Default values, timeouts in ms */
10 #define MESH_TTL 		31
11 #define MESH_DEFAULT_ELEMENT_TTL 31
12 #define MESH_MAX_RETR	 	3
13 #define MESH_RET_T 		100
14 #define MESH_CONF_T 		100
15 #define MESH_HOLD_T 		100
16 
17 #define MESH_PATH_TIMEOUT	5000
18 #define MESH_RANN_INTERVAL      5000
19 #define MESH_PATH_TO_ROOT_TIMEOUT      6000
20 #define MESH_ROOT_INTERVAL     5000
21 #define MESH_ROOT_CONFIRMATION_INTERVAL 2000
22 #define MESH_DEFAULT_PLINK_TIMEOUT	1800 /* timeout in seconds */
23 
24 /*
25  * Minimum interval between two consecutive PREQs originated by the same
26  * interface
27  */
28 #define MESH_PREQ_MIN_INT	10
29 #define MESH_PERR_MIN_INT	100
30 #define MESH_DIAM_TRAVERSAL_TIME 50
31 
32 #define MESH_RSSI_THRESHOLD	0
33 
34 /*
35  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
36  * before timing out.  This way it will remain ACTIVE and no data frames
37  * will be unnecessarily held in the pending queue.
38  */
39 #define MESH_PATH_REFRESH_TIME			1000
40 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
41 
42 /* Default maximum number of established plinks per interface */
43 #define MESH_MAX_ESTAB_PLINKS	32
44 
45 #define MESH_MAX_PREQ_RETRIES	4
46 
47 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
48 
49 #define MESH_DEFAULT_BEACON_INTERVAL	1000	/* in 1024 us units (=TUs) */
50 #define MESH_DEFAULT_DTIM_PERIOD	2
51 #define MESH_DEFAULT_AWAKE_WINDOW	10	/* in 1024 us units (=TUs) */
52 
53 const struct mesh_config default_mesh_config = {
54 	.dot11MeshRetryTimeout = MESH_RET_T,
55 	.dot11MeshConfirmTimeout = MESH_CONF_T,
56 	.dot11MeshHoldingTimeout = MESH_HOLD_T,
57 	.dot11MeshMaxRetries = MESH_MAX_RETR,
58 	.dot11MeshTTL = MESH_TTL,
59 	.element_ttl = MESH_DEFAULT_ELEMENT_TTL,
60 	.auto_open_plinks = true,
61 	.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
62 	.dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
63 	.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
64 	.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
65 	.dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
66 	.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
67 	.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
68 	.path_refresh_time = MESH_PATH_REFRESH_TIME,
69 	.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
70 	.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
71 	.dot11MeshGateAnnouncementProtocol = false,
72 	.dot11MeshForwarding = true,
73 	.rssi_threshold = MESH_RSSI_THRESHOLD,
74 	.ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
75 	.dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
76 	.dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
77 	.dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
78 	.power_mode = NL80211_MESH_POWER_ACTIVE,
79 	.dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
80 	.plink_timeout = MESH_DEFAULT_PLINK_TIMEOUT,
81 	.dot11MeshNolearn = false,
82 };
83 
84 const struct mesh_setup default_mesh_setup = {
85 	/* cfg80211_join_mesh() will pick a channel if needed */
86 	.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
87 	.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
88 	.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
89 	.auth_id = 0, /* open */
90 	.ie = NULL,
91 	.ie_len = 0,
92 	.is_secure = false,
93 	.user_mpm = false,
94 	.beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
95 	.dtim_period = MESH_DEFAULT_DTIM_PERIOD,
96 };
97 
98 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
99 			 struct net_device *dev,
100 			 struct mesh_setup *setup,
101 			 const struct mesh_config *conf)
102 {
103 	struct wireless_dev *wdev = dev->ieee80211_ptr;
104 	int err;
105 
106 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
107 
108 	ASSERT_WDEV_LOCK(wdev);
109 
110 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
111 		return -EOPNOTSUPP;
112 
113 	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
114 	      setup->is_secure)
115 		return -EOPNOTSUPP;
116 
117 	if (wdev->mesh_id_len)
118 		return -EALREADY;
119 
120 	if (!setup->mesh_id_len)
121 		return -EINVAL;
122 
123 	if (!rdev->ops->join_mesh)
124 		return -EOPNOTSUPP;
125 
126 	if (!setup->chandef.chan) {
127 		/* if no channel explicitly given, use preset channel */
128 		setup->chandef = wdev->preset_chandef;
129 	}
130 
131 	if (!setup->chandef.chan) {
132 		/* if we don't have that either, use the first usable channel */
133 		enum nl80211_band band;
134 
135 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
136 			struct ieee80211_supported_band *sband;
137 			struct ieee80211_channel *chan;
138 			int i;
139 
140 			sband = rdev->wiphy.bands[band];
141 			if (!sband)
142 				continue;
143 
144 			for (i = 0; i < sband->n_channels; i++) {
145 				chan = &sband->channels[i];
146 				if (chan->flags & (IEEE80211_CHAN_NO_IR |
147 						   IEEE80211_CHAN_DISABLED |
148 						   IEEE80211_CHAN_RADAR))
149 					continue;
150 				setup->chandef.chan = chan;
151 				break;
152 			}
153 
154 			if (setup->chandef.chan)
155 				break;
156 		}
157 
158 		/* no usable channel ... */
159 		if (!setup->chandef.chan)
160 			return -EINVAL;
161 
162 		setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
163 		setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
164 	}
165 
166 	/*
167 	 * check if basic rates are available otherwise use mandatory rates as
168 	 * basic rates
169 	 */
170 	if (!setup->basic_rates) {
171 		enum nl80211_bss_scan_width scan_width;
172 		struct ieee80211_supported_band *sband =
173 				rdev->wiphy.bands[setup->chandef.chan->band];
174 
175 		if (setup->chandef.chan->band == NL80211_BAND_2GHZ) {
176 			int i;
177 
178 			/*
179 			 * Older versions selected the mandatory rates for
180 			 * 2.4 GHz as well, but were broken in that only
181 			 * 1 Mbps was regarded as a mandatory rate. Keep
182 			 * using just 1 Mbps as the default basic rate for
183 			 * mesh to be interoperable with older versions.
184 			 */
185 			for (i = 0; i < sband->n_bitrates; i++) {
186 				if (sband->bitrates[i].bitrate == 10) {
187 					setup->basic_rates = BIT(i);
188 					break;
189 				}
190 			}
191 		} else {
192 			scan_width = cfg80211_chandef_to_scan_width(&setup->chandef);
193 			setup->basic_rates = ieee80211_mandatory_rates(sband,
194 								       scan_width);
195 		}
196 	}
197 
198 	err = cfg80211_chandef_dfs_required(&rdev->wiphy,
199 					    &setup->chandef,
200 					    NL80211_IFTYPE_MESH_POINT);
201 	if (err < 0)
202 		return err;
203 	if (err > 0 && !setup->userspace_handles_dfs)
204 		return -EINVAL;
205 
206 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef,
207 				     NL80211_IFTYPE_MESH_POINT))
208 		return -EINVAL;
209 
210 	err = rdev_join_mesh(rdev, dev, conf, setup);
211 	if (!err) {
212 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
213 		wdev->mesh_id_len = setup->mesh_id_len;
214 		wdev->chandef = setup->chandef;
215 		wdev->beacon_interval = setup->beacon_interval;
216 	}
217 
218 	return err;
219 }
220 
221 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
222 			      struct wireless_dev *wdev,
223 			      struct cfg80211_chan_def *chandef)
224 {
225 	int err;
226 
227 	/*
228 	 * Workaround for libertas (only!), it puts the interface
229 	 * into mesh mode but doesn't implement join_mesh. Instead,
230 	 * it is configured via sysfs and then joins the mesh when
231 	 * you set the channel. Note that the libertas mesh isn't
232 	 * compatible with 802.11 mesh.
233 	 */
234 	if (rdev->ops->libertas_set_mesh_channel) {
235 		if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
236 			return -EINVAL;
237 
238 		if (!netif_running(wdev->netdev))
239 			return -ENETDOWN;
240 
241 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
242 						     chandef->chan);
243 		if (!err)
244 			wdev->chandef = *chandef;
245 
246 		return err;
247 	}
248 
249 	if (wdev->mesh_id_len)
250 		return -EBUSY;
251 
252 	wdev->preset_chandef = *chandef;
253 	return 0;
254 }
255 
256 int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
257 			  struct net_device *dev)
258 {
259 	struct wireless_dev *wdev = dev->ieee80211_ptr;
260 	int err;
261 
262 	ASSERT_WDEV_LOCK(wdev);
263 
264 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
265 		return -EOPNOTSUPP;
266 
267 	if (!rdev->ops->leave_mesh)
268 		return -EOPNOTSUPP;
269 
270 	if (!wdev->mesh_id_len)
271 		return -ENOTCONN;
272 
273 	err = rdev_leave_mesh(rdev, dev);
274 	if (!err) {
275 		wdev->conn_owner_nlportid = 0;
276 		wdev->mesh_id_len = 0;
277 		wdev->beacon_interval = 0;
278 		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
279 		rdev_set_qos_map(rdev, dev, NULL);
280 		cfg80211_sched_dfs_chan_update(rdev);
281 	}
282 
283 	return err;
284 }
285 
286 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
287 			struct net_device *dev)
288 {
289 	struct wireless_dev *wdev = dev->ieee80211_ptr;
290 	int err;
291 
292 	wdev_lock(wdev);
293 	err = __cfg80211_leave_mesh(rdev, dev);
294 	wdev_unlock(wdev);
295 
296 	return err;
297 }
298