xref: /kernel/linux/linux-5.10/net/wireless/mesh.c (revision 8c2ecf20) 
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
53const 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
84const 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
98int __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
221int 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
256int __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
286int 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