xref: /openbmc/linux/net/wireless/mesh.c (revision 37744fee)
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 };
82 
83 const struct mesh_setup default_mesh_setup = {
84 	/* cfg80211_join_mesh() will pick a channel if needed */
85 	.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
86 	.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
87 	.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
88 	.auth_id = 0, /* open */
89 	.ie = NULL,
90 	.ie_len = 0,
91 	.is_secure = false,
92 	.user_mpm = false,
93 	.beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
94 	.dtim_period = MESH_DEFAULT_DTIM_PERIOD,
95 };
96 
97 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
98 			 struct net_device *dev,
99 			 struct mesh_setup *setup,
100 			 const struct mesh_config *conf)
101 {
102 	struct wireless_dev *wdev = dev->ieee80211_ptr;
103 	int err;
104 
105 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
106 
107 	ASSERT_WDEV_LOCK(wdev);
108 
109 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
110 		return -EOPNOTSUPP;
111 
112 	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
113 	      setup->is_secure)
114 		return -EOPNOTSUPP;
115 
116 	if (wdev->mesh_id_len)
117 		return -EALREADY;
118 
119 	if (!setup->mesh_id_len)
120 		return -EINVAL;
121 
122 	if (!rdev->ops->join_mesh)
123 		return -EOPNOTSUPP;
124 
125 	if (!setup->chandef.chan) {
126 		/* if no channel explicitly given, use preset channel */
127 		setup->chandef = wdev->preset_chandef;
128 	}
129 
130 	if (!setup->chandef.chan) {
131 		/* if we don't have that either, use the first usable channel */
132 		enum nl80211_band band;
133 
134 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
135 			struct ieee80211_supported_band *sband;
136 			struct ieee80211_channel *chan;
137 			int i;
138 
139 			sband = rdev->wiphy.bands[band];
140 			if (!sband)
141 				continue;
142 
143 			for (i = 0; i < sband->n_channels; i++) {
144 				chan = &sband->channels[i];
145 				if (chan->flags & (IEEE80211_CHAN_NO_IR |
146 						   IEEE80211_CHAN_DISABLED |
147 						   IEEE80211_CHAN_RADAR))
148 					continue;
149 				setup->chandef.chan = chan;
150 				break;
151 			}
152 
153 			if (setup->chandef.chan)
154 				break;
155 		}
156 
157 		/* no usable channel ... */
158 		if (!setup->chandef.chan)
159 			return -EINVAL;
160 
161 		setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
162 		setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
163 	}
164 
165 	/*
166 	 * check if basic rates are available otherwise use mandatory rates as
167 	 * basic rates
168 	 */
169 	if (!setup->basic_rates) {
170 		enum nl80211_bss_scan_width scan_width;
171 		struct ieee80211_supported_band *sband =
172 				rdev->wiphy.bands[setup->chandef.chan->band];
173 
174 		if (setup->chandef.chan->band == NL80211_BAND_2GHZ) {
175 			int i;
176 
177 			/*
178 			 * Older versions selected the mandatory rates for
179 			 * 2.4 GHz as well, but were broken in that only
180 			 * 1 Mbps was regarded as a mandatory rate. Keep
181 			 * using just 1 Mbps as the default basic rate for
182 			 * mesh to be interoperable with older versions.
183 			 */
184 			for (i = 0; i < sband->n_bitrates; i++) {
185 				if (sband->bitrates[i].bitrate == 10) {
186 					setup->basic_rates = BIT(i);
187 					break;
188 				}
189 			}
190 		} else {
191 			scan_width = cfg80211_chandef_to_scan_width(&setup->chandef);
192 			setup->basic_rates = ieee80211_mandatory_rates(sband,
193 								       scan_width);
194 		}
195 	}
196 
197 	err = cfg80211_chandef_dfs_required(&rdev->wiphy,
198 					    &setup->chandef,
199 					    NL80211_IFTYPE_MESH_POINT);
200 	if (err < 0)
201 		return err;
202 	if (err > 0 && !setup->userspace_handles_dfs)
203 		return -EINVAL;
204 
205 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef,
206 				     NL80211_IFTYPE_MESH_POINT))
207 		return -EINVAL;
208 
209 	err = rdev_join_mesh(rdev, dev, conf, setup);
210 	if (!err) {
211 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
212 		wdev->mesh_id_len = setup->mesh_id_len;
213 		wdev->chandef = setup->chandef;
214 		wdev->beacon_interval = setup->beacon_interval;
215 	}
216 
217 	return err;
218 }
219 
220 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
221 			      struct wireless_dev *wdev,
222 			      struct cfg80211_chan_def *chandef)
223 {
224 	int err;
225 
226 	/*
227 	 * Workaround for libertas (only!), it puts the interface
228 	 * into mesh mode but doesn't implement join_mesh. Instead,
229 	 * it is configured via sysfs and then joins the mesh when
230 	 * you set the channel. Note that the libertas mesh isn't
231 	 * compatible with 802.11 mesh.
232 	 */
233 	if (rdev->ops->libertas_set_mesh_channel) {
234 		if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
235 			return -EINVAL;
236 
237 		if (!netif_running(wdev->netdev))
238 			return -ENETDOWN;
239 
240 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
241 						     chandef->chan);
242 		if (!err)
243 			wdev->chandef = *chandef;
244 
245 		return err;
246 	}
247 
248 	if (wdev->mesh_id_len)
249 		return -EBUSY;
250 
251 	wdev->preset_chandef = *chandef;
252 	return 0;
253 }
254 
255 int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
256 			  struct net_device *dev)
257 {
258 	struct wireless_dev *wdev = dev->ieee80211_ptr;
259 	int err;
260 
261 	ASSERT_WDEV_LOCK(wdev);
262 
263 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
264 		return -EOPNOTSUPP;
265 
266 	if (!rdev->ops->leave_mesh)
267 		return -EOPNOTSUPP;
268 
269 	if (!wdev->mesh_id_len)
270 		return -ENOTCONN;
271 
272 	err = rdev_leave_mesh(rdev, dev);
273 	if (!err) {
274 		wdev->conn_owner_nlportid = 0;
275 		wdev->mesh_id_len = 0;
276 		wdev->beacon_interval = 0;
277 		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
278 		rdev_set_qos_map(rdev, dev, NULL);
279 		cfg80211_sched_dfs_chan_update(rdev);
280 	}
281 
282 	return err;
283 }
284 
285 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
286 			struct net_device *dev)
287 {
288 	struct wireless_dev *wdev = dev->ieee80211_ptr;
289 	int err;
290 
291 	wdev_lock(wdev);
292 	err = __cfg80211_leave_mesh(rdev, dev);
293 	wdev_unlock(wdev);
294 
295 	return err;
296 }
297