xref: /linux/net/wireless/mesh.c (revision 836265d31631e28000fc8917ce697fc687a58724) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Portions
4  * Copyright (C) 2022-2024 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 (wdev->links[0].cac_started)
131 		return -EBUSY;
132 
133 	if (!setup->chandef.chan) {
134 		/* if no channel explicitly given, use preset channel */
135 		setup->chandef = wdev->u.mesh.preset_chandef;
136 	}
137 
138 	if (!setup->chandef.chan) {
139 		/* if we don't have that either, use the first usable channel */
140 		enum nl80211_band band;
141 
142 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
143 			struct ieee80211_supported_band *sband;
144 			struct ieee80211_channel *chan;
145 			int i;
146 
147 			sband = rdev->wiphy.bands[band];
148 			if (!sband)
149 				continue;
150 
151 			for (i = 0; i < sband->n_channels; i++) {
152 				chan = &sband->channels[i];
153 				if (chan->flags & (IEEE80211_CHAN_NO_IR |
154 						   IEEE80211_CHAN_DISABLED |
155 						   IEEE80211_CHAN_RADAR))
156 					continue;
157 				setup->chandef.chan = chan;
158 				break;
159 			}
160 
161 			if (setup->chandef.chan)
162 				break;
163 		}
164 
165 		/* no usable channel ... */
166 		if (!setup->chandef.chan)
167 			return -EINVAL;
168 
169 		setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
170 		setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
171 	}
172 
173 	/*
174 	 * check if basic rates are available otherwise use mandatory rates as
175 	 * basic rates
176 	 */
177 	if (!setup->basic_rates) {
178 		struct ieee80211_supported_band *sband =
179 				rdev->wiphy.bands[setup->chandef.chan->band];
180 
181 		if (setup->chandef.chan->band == NL80211_BAND_2GHZ) {
182 			int i;
183 
184 			/*
185 			 * Older versions selected the mandatory rates for
186 			 * 2.4 GHz as well, but were broken in that only
187 			 * 1 Mbps was regarded as a mandatory rate. Keep
188 			 * using just 1 Mbps as the default basic rate for
189 			 * mesh to be interoperable with older versions.
190 			 */
191 			for (i = 0; i < sband->n_bitrates; i++) {
192 				if (sband->bitrates[i].bitrate == 10) {
193 					setup->basic_rates = BIT(i);
194 					break;
195 				}
196 			}
197 		} else {
198 			setup->basic_rates = ieee80211_mandatory_rates(sband);
199 		}
200 	}
201 
202 	err = cfg80211_chandef_dfs_required(&rdev->wiphy,
203 					    &setup->chandef,
204 					    NL80211_IFTYPE_MESH_POINT);
205 	if (err < 0)
206 		return err;
207 	if (err > 0 && !setup->userspace_handles_dfs)
208 		return -EINVAL;
209 
210 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef,
211 				     NL80211_IFTYPE_MESH_POINT))
212 		return -EINVAL;
213 
214 	err = rdev_join_mesh(rdev, dev, conf, setup);
215 	if (!err) {
216 		memcpy(wdev->u.mesh.id, setup->mesh_id, setup->mesh_id_len);
217 		wdev->u.mesh.id_len = setup->mesh_id_len;
218 		wdev->u.mesh.chandef = setup->chandef;
219 		wdev->u.mesh.beacon_interval = setup->beacon_interval;
220 	}
221 
222 	return err;
223 }
224 
225 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
226 			      struct wireless_dev *wdev,
227 			      struct cfg80211_chan_def *chandef)
228 {
229 	int err;
230 
231 	/*
232 	 * Workaround for libertas (only!), it puts the interface
233 	 * into mesh mode but doesn't implement join_mesh. Instead,
234 	 * it is configured via sysfs and then joins the mesh when
235 	 * you set the channel. Note that the libertas mesh isn't
236 	 * compatible with 802.11 mesh.
237 	 */
238 	if (rdev->ops->libertas_set_mesh_channel) {
239 		if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
240 			return -EINVAL;
241 
242 		if (!netif_running(wdev->netdev))
243 			return -ENETDOWN;
244 
245 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
246 						     chandef->chan);
247 		if (!err)
248 			wdev->u.mesh.chandef = *chandef;
249 
250 		return err;
251 	}
252 
253 	if (wdev->u.mesh.id_len)
254 		return -EBUSY;
255 
256 	wdev->u.mesh.preset_chandef = *chandef;
257 	return 0;
258 }
259 
260 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
261 			struct net_device *dev)
262 {
263 	struct wireless_dev *wdev = dev->ieee80211_ptr;
264 	int err;
265 
266 	lockdep_assert_wiphy(wdev->wiphy);
267 
268 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
269 		return -EOPNOTSUPP;
270 
271 	if (!rdev->ops->leave_mesh)
272 		return -EOPNOTSUPP;
273 
274 	if (!wdev->u.mesh.id_len)
275 		return -ENOTCONN;
276 
277 	err = rdev_leave_mesh(rdev, dev);
278 	if (!err) {
279 		wdev->conn_owner_nlportid = 0;
280 		wdev->u.mesh.id_len = 0;
281 		wdev->u.mesh.beacon_interval = 0;
282 		memset(&wdev->u.mesh.chandef, 0,
283 		       sizeof(wdev->u.mesh.chandef));
284 		rdev_set_qos_map(rdev, dev, NULL);
285 		cfg80211_sched_dfs_chan_update(rdev);
286 	}
287 
288 	return err;
289 }
290