xref: /kernel/linux/linux-6.6/net/wireless/mesh.c (revision 62306a36) 
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Portions
4 * Copyright (C) 2022 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
57const 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
88const 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
102int __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	ASSERT_WDEV_LOCK(wdev);
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		enum nl80211_bss_scan_width scan_width;
176		struct ieee80211_supported_band *sband =
177				rdev->wiphy.bands[setup->chandef.chan->band];
178
179		if (setup->chandef.chan->band == NL80211_BAND_2GHZ) {
180			int i;
181
182			/*
183			 * Older versions selected the mandatory rates for
184			 * 2.4 GHz as well, but were broken in that only
185			 * 1 Mbps was regarded as a mandatory rate. Keep
186			 * using just 1 Mbps as the default basic rate for
187			 * mesh to be interoperable with older versions.
188			 */
189			for (i = 0; i < sband->n_bitrates; i++) {
190				if (sband->bitrates[i].bitrate == 10) {
191					setup->basic_rates = BIT(i);
192					break;
193				}
194			}
195		} else {
196			scan_width = cfg80211_chandef_to_scan_width(&setup->chandef);
197			setup->basic_rates = ieee80211_mandatory_rates(sband,
198								       scan_width);
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
225int 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
260int __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	ASSERT_WDEV_LOCK(wdev);
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
291int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
292			struct net_device *dev)
293{
294	struct wireless_dev *wdev = dev->ieee80211_ptr;
295	int err;
296
297	wdev_lock(wdev);
298	err = __cfg80211_leave_mesh(rdev, dev);
299	wdev_unlock(wdev);
300
301	return err;
302}
303