xref: /linux/net/wireless/mesh.c (revision e467705a9fb37f51595aa6deaca085ccb4005454) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Portions
4  * Copyright (C) 2022-2023 Intel Corporation
5  */
6 #include <linux/ieee80211.h>
7 #include <linux/export.h>
8 #include <net/cfg80211.h>
9 #include "nl80211.h"
10 #include "core.h"
11 #include "rdev-ops.h"
12 
13 /* Default values, timeouts in ms */
14 #define MESH_TTL 		31
15 #define MESH_DEFAULT_ELEMENT_TTL 31
16 #define MESH_MAX_RETR	 	3
17 #define MESH_RET_T 		100
18 #define MESH_CONF_T 		100
19 #define MESH_HOLD_T 		100
20 
21 #define MESH_PATH_TIMEOUT	5000
22 #define MESH_RANN_INTERVAL      5000
23 #define MESH_PATH_TO_ROOT_TIMEOUT      6000
24 #define MESH_ROOT_INTERVAL     5000
25 #define MESH_ROOT_CONFIRMATION_INTERVAL 2000
26 #define MESH_DEFAULT_PLINK_TIMEOUT	1800 /* timeout in seconds */
27 
28 /*
29  * Minimum interval between two consecutive PREQs originated by the same
30  * interface
31  */
32 #define MESH_PREQ_MIN_INT	10
33 #define MESH_PERR_MIN_INT	100
34 #define MESH_DIAM_TRAVERSAL_TIME 50
35 
36 #define MESH_RSSI_THRESHOLD	0
37 
38 /*
39  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
40  * before timing out.  This way it will remain ACTIVE and no data frames
41  * will be unnecessarily held in the pending queue.
42  */
43 #define MESH_PATH_REFRESH_TIME			1000
44 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)
45 
46 /* Default maximum number of established plinks per interface */
47 #define MESH_MAX_ESTAB_PLINKS	32
48 
49 #define MESH_MAX_PREQ_RETRIES	4
50 
51 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50
52 
53 #define MESH_DEFAULT_BEACON_INTERVAL	1000	/* in 1024 us units (=TUs) */
54 #define MESH_DEFAULT_DTIM_PERIOD	2
55 #define MESH_DEFAULT_AWAKE_WINDOW	10	/* in 1024 us units (=TUs) */
56 
57 const struct mesh_config default_mesh_config = {
58 	.dot11MeshRetryTimeout = MESH_RET_T,
59 	.dot11MeshConfirmTimeout = MESH_CONF_T,
60 	.dot11MeshHoldingTimeout = MESH_HOLD_T,
61 	.dot11MeshMaxRetries = MESH_MAX_RETR,
62 	.dot11MeshTTL = MESH_TTL,
63 	.element_ttl = MESH_DEFAULT_ELEMENT_TTL,
64 	.auto_open_plinks = true,
65 	.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
66 	.dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
67 	.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
68 	.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
69 	.dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
70 	.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
71 	.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
72 	.path_refresh_time = MESH_PATH_REFRESH_TIME,
73 	.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
74 	.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
75 	.dot11MeshGateAnnouncementProtocol = false,
76 	.dot11MeshForwarding = true,
77 	.rssi_threshold = MESH_RSSI_THRESHOLD,
78 	.ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
79 	.dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
80 	.dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
81 	.dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
82 	.power_mode = NL80211_MESH_POWER_ACTIVE,
83 	.dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
84 	.plink_timeout = MESH_DEFAULT_PLINK_TIMEOUT,
85 	.dot11MeshNolearn = false,
86 };
87 
88 const struct mesh_setup default_mesh_setup = {
89 	/* cfg80211_join_mesh() will pick a channel if needed */
90 	.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
91 	.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
92 	.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
93 	.auth_id = 0, /* open */
94 	.ie = NULL,
95 	.ie_len = 0,
96 	.is_secure = false,
97 	.user_mpm = false,
98 	.beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
99 	.dtim_period = MESH_DEFAULT_DTIM_PERIOD,
100 };
101 
102 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
103 			 struct net_device *dev,
104 			 struct mesh_setup *setup,
105 			 const struct mesh_config *conf)
106 {
107 	struct wireless_dev *wdev = dev->ieee80211_ptr;
108 	int err;
109 
110 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);
111 
112 	lockdep_assert_wiphy(wdev->wiphy);
113 
114 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
115 		return -EOPNOTSUPP;
116 
117 	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
118 	      setup->is_secure)
119 		return -EOPNOTSUPP;
120 
121 	if (wdev->u.mesh.id_len)
122 		return -EALREADY;
123 
124 	if (!setup->mesh_id_len)
125 		return -EINVAL;
126 
127 	if (!rdev->ops->join_mesh)
128 		return -EOPNOTSUPP;
129 
130 	if (!setup->chandef.chan) {
131 		/* if no channel explicitly given, use preset channel */
132 		setup->chandef = wdev->u.mesh.preset_chandef;
133 	}
134 
135 	if (!setup->chandef.chan) {
136 		/* if we don't have that either, use the first usable channel */
137 		enum nl80211_band band;
138 
139 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
140 			struct ieee80211_supported_band *sband;
141 			struct ieee80211_channel *chan;
142 			int i;
143 
144 			sband = rdev->wiphy.bands[band];
145 			if (!sband)
146 				continue;
147 
148 			for (i = 0; i < sband->n_channels; i++) {
149 				chan = &sband->channels[i];
150 				if (chan->flags & (IEEE80211_CHAN_NO_IR |
151 						   IEEE80211_CHAN_DISABLED |
152 						   IEEE80211_CHAN_RADAR))
153 					continue;
154 				setup->chandef.chan = chan;
155 				break;
156 			}
157 
158 			if (setup->chandef.chan)
159 				break;
160 		}
161 
162 		/* no usable channel ... */
163 		if (!setup->chandef.chan)
164 			return -EINVAL;
165 
166 		setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
167 		setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
168 	}
169 
170 	/*
171 	 * check if basic rates are available otherwise use mandatory rates as
172 	 * basic rates
173 	 */
174 	if (!setup->basic_rates) {
175 		struct ieee80211_supported_band *sband =
176 				rdev->wiphy.bands[setup->chandef.chan->band];
177 
178 		if (setup->chandef.chan->band == NL80211_BAND_2GHZ) {
179 			int i;
180 
181 			/*
182 			 * Older versions selected the mandatory rates for
183 			 * 2.4 GHz as well, but were broken in that only
184 			 * 1 Mbps was regarded as a mandatory rate. Keep
185 			 * using just 1 Mbps as the default basic rate for
186 			 * mesh to be interoperable with older versions.
187 			 */
188 			for (i = 0; i < sband->n_bitrates; i++) {
189 				if (sband->bitrates[i].bitrate == 10) {
190 					setup->basic_rates = BIT(i);
191 					break;
192 				}
193 			}
194 		} else {
195 			setup->basic_rates = ieee80211_mandatory_rates(sband);
196 		}
197 	}
198 
199 	err = cfg80211_chandef_dfs_required(&rdev->wiphy,
200 					    &setup->chandef,
201 					    NL80211_IFTYPE_MESH_POINT);
202 	if (err < 0)
203 		return err;
204 	if (err > 0 && !setup->userspace_handles_dfs)
205 		return -EINVAL;
206 
207 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef,
208 				     NL80211_IFTYPE_MESH_POINT))
209 		return -EINVAL;
210 
211 	err = rdev_join_mesh(rdev, dev, conf, setup);
212 	if (!err) {
213 		memcpy(wdev->u.mesh.id, setup->mesh_id, setup->mesh_id_len);
214 		wdev->u.mesh.id_len = setup->mesh_id_len;
215 		wdev->u.mesh.chandef = setup->chandef;
216 		wdev->u.mesh.beacon_interval = setup->beacon_interval;
217 	}
218 
219 	return err;
220 }
221 
222 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
223 			      struct wireless_dev *wdev,
224 			      struct cfg80211_chan_def *chandef)
225 {
226 	int err;
227 
228 	/*
229 	 * Workaround for libertas (only!), it puts the interface
230 	 * into mesh mode but doesn't implement join_mesh. Instead,
231 	 * it is configured via sysfs and then joins the mesh when
232 	 * you set the channel. Note that the libertas mesh isn't
233 	 * compatible with 802.11 mesh.
234 	 */
235 	if (rdev->ops->libertas_set_mesh_channel) {
236 		if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
237 			return -EINVAL;
238 
239 		if (!netif_running(wdev->netdev))
240 			return -ENETDOWN;
241 
242 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
243 						     chandef->chan);
244 		if (!err)
245 			wdev->u.mesh.chandef = *chandef;
246 
247 		return err;
248 	}
249 
250 	if (wdev->u.mesh.id_len)
251 		return -EBUSY;
252 
253 	wdev->u.mesh.preset_chandef = *chandef;
254 	return 0;
255 }
256 
257 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
258 			struct net_device *dev)
259 {
260 	struct wireless_dev *wdev = dev->ieee80211_ptr;
261 	int err;
262 
263 	lockdep_assert_wiphy(wdev->wiphy);
264 
265 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
266 		return -EOPNOTSUPP;
267 
268 	if (!rdev->ops->leave_mesh)
269 		return -EOPNOTSUPP;
270 
271 	if (!wdev->u.mesh.id_len)
272 		return -ENOTCONN;
273 
274 	err = rdev_leave_mesh(rdev, dev);
275 	if (!err) {
276 		wdev->conn_owner_nlportid = 0;
277 		wdev->u.mesh.id_len = 0;
278 		wdev->u.mesh.beacon_interval = 0;
279 		memset(&wdev->u.mesh.chandef, 0,
280 		       sizeof(wdev->u.mesh.chandef));
281 		rdev_set_qos_map(rdev, dev, NULL);
282 		cfg80211_sched_dfs_chan_update(rdev);
283 	}
284 
285 	return err;
286 }
287