net/wireless/mesh.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 #include <linux/ieee80211.h>
 #include <linux/export.h>
 #include <net/cfg80211.h>
 #include "nl80211.h"
 #include "core.h"
 #include "rdev-ops.h"

 /* Default values, timeouts in ms */
 #define MESH_TTL 		31
 #define MESH_DEFAULT_ELEMENT_TTL 31
 #define MESH_MAX_RETR	 	3
 #define MESH_RET_T 		100
 #define MESH_CONF_T 		100
 #define MESH_HOLD_T 		100

 #define MESH_PATH_TIMEOUT	5000
 #define MESH_RANN_INTERVAL      5000
 #define MESH_PATH_TO_ROOT_TIMEOUT      6000
 #define MESH_ROOT_INTERVAL     5000
 #define MESH_ROOT_CONFIRMATION_INTERVAL 2000
 #define MESH_DEFAULT_PLINK_TIMEOUT	1800 /* timeout in seconds */

 /*
  * Minimum interval between two consecutive PREQs originated by the same
  * interface
  */
 #define MESH_PREQ_MIN_INT	10
 #define MESH_PERR_MIN_INT	100
 #define MESH_DIAM_TRAVERSAL_TIME 50

 #define MESH_RSSI_THRESHOLD	0

 /*
  * A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
  * before timing out.  This way it will remain ACTIVE and no data frames
  * will be unnecessarily held in the pending queue.
  */
 #define MESH_PATH_REFRESH_TIME			1000
 #define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)

 /* Default maximum number of established plinks per interface */
 #define MESH_MAX_ESTAB_PLINKS	32

 #define MESH_MAX_PREQ_RETRIES	4

 #define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50

 #define MESH_DEFAULT_BEACON_INTERVAL	1000	/* in 1024 us units (=TUs) */
 #define MESH_DEFAULT_DTIM_PERIOD	2
 #define MESH_DEFAULT_AWAKE_WINDOW	10	/* in 1024 us units (=TUs) */

 const struct mesh_config default_mesh_config = {
 	.dot11MeshRetryTimeout = MESH_RET_T,
 	.dot11MeshConfirmTimeout = MESH_CONF_T,
 	.dot11MeshHoldingTimeout = MESH_HOLD_T,
 	.dot11MeshMaxRetries = MESH_MAX_RETR,
 	.dot11MeshTTL = MESH_TTL,
 	.element_ttl = MESH_DEFAULT_ELEMENT_TTL,
 	.auto_open_plinks = true,
 	.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
 	.dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
 	.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
 	.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
 	.dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
 	.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
 	.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
 	.path_refresh_time = MESH_PATH_REFRESH_TIME,
 	.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
 	.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
 	.dot11MeshGateAnnouncementProtocol = false,
 	.dot11MeshForwarding = true,
 	.rssi_threshold = MESH_RSSI_THRESHOLD,
 	.ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
 	.dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
 	.dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
 	.dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
 	.power_mode = NL80211_MESH_POWER_ACTIVE,
 	.dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
 	.plink_timeout = MESH_DEFAULT_PLINK_TIMEOUT,
 	.dot11MeshNolearn = false,
 };

 const struct mesh_setup default_mesh_setup = {
 	/* cfg80211_join_mesh() will pick a channel if needed */
 	.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
 	.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
 	.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
 	.auth_id = 0, /* open */
 	.ie = NULL,
 	.ie_len = 0,
 	.is_secure = false,
 	.user_mpm = false,
 	.beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
 	.dtim_period = MESH_DEFAULT_DTIM_PERIOD,
 };

 int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
 			 struct net_device *dev,
 			 struct mesh_setup *setup,
 			 const struct mesh_config *conf)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;

 	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);

 	ASSERT_WDEV_LOCK(wdev);

 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 		return -EOPNOTSUPP;

 	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
 	      setup->is_secure)
 		return -EOPNOTSUPP;

 	if (wdev->mesh_id_len)
 		return -EALREADY;

 	if (!setup->mesh_id_len)
 		return -EINVAL;

 	if (!rdev->ops->join_mesh)
 		return -EOPNOTSUPP;

 	if (!setup->chandef.chan) {
 		/* if no channel explicitly given, use preset channel */
 		setup->chandef = wdev->preset_chandef;
 	}

 	if (!setup->chandef.chan) {
 		/* if we don't have that either, use the first usable channel */
 		enum nl80211_band band;

 		for (band = 0; band < NUM_NL80211_BANDS; band++) {
 			struct ieee80211_supported_band *sband;
 			struct ieee80211_channel *chan;
 			int i;

 			sband = rdev->wiphy.bands[band];
 			if (!sband)
 				continue;

 			for (i = 0; i < sband->n_channels; i++) {
 				chan = &sband->channels[i];
 				if (chan->flags & (IEEE80211_CHAN_NO_IR |
 						   IEEE80211_CHAN_DISABLED |
 						   IEEE80211_CHAN_RADAR))
 					continue;
 				setup->chandef.chan = chan;
 				break;
 			}

 			if (setup->chandef.chan)
 				break;
 		}

 		/* no usable channel ... */
 		if (!setup->chandef.chan)
 			return -EINVAL;

 		setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
 		setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
 	}

 	/*
 	 * check if basic rates are available otherwise use mandatory rates as
 	 * basic rates
 	 */
 	if (!setup->basic_rates) {
 		enum nl80211_bss_scan_width scan_width;
 		struct ieee80211_supported_band *sband =
 				rdev->wiphy.bands[setup->chandef.chan->band];

 		if (setup->chandef.chan->band == NL80211_BAND_2GHZ) {
 			int i;

 			/*
 			 * Older versions selected the mandatory rates for
 			 * 2.4 GHz as well, but were broken in that only
 			 * 1 Mbps was regarded as a mandatory rate. Keep
 			 * using just 1 Mbps as the default basic rate for
 			 * mesh to be interoperable with older versions.
 			 */
 			for (i = 0; i < sband->n_bitrates; i++) {
 				if (sband->bitrates[i].bitrate == 10) {
 					setup->basic_rates = BIT(i);
 					break;
 				}
 			}
 		} else {
 			scan_width = cfg80211_chandef_to_scan_width(&setup->chandef);
 			setup->basic_rates = ieee80211_mandatory_rates(sband,
 								       scan_width);
 		}
 	}

 	err = cfg80211_chandef_dfs_required(&rdev->wiphy,
 					    &setup->chandef,
 					    NL80211_IFTYPE_MESH_POINT);
 	if (err < 0)
 		return err;
 	if (err > 0 && !setup->userspace_handles_dfs)
 		return -EINVAL;

 	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef,
 				     NL80211_IFTYPE_MESH_POINT))
 		return -EINVAL;

 	err = rdev_join_mesh(rdev, dev, conf, setup);
 	if (!err) {
 		memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
 		wdev->mesh_id_len = setup->mesh_id_len;
 		wdev->chandef = setup->chandef;
 		wdev->beacon_interval = setup->beacon_interval;
 	}

 	return err;
 }

 int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
 			      struct wireless_dev *wdev,
 			      struct cfg80211_chan_def *chandef)
 {
 	int err;

 	/*
 	 * Workaround for libertas (only!), it puts the interface
 	 * into mesh mode but doesn't implement join_mesh. Instead,
 	 * it is configured via sysfs and then joins the mesh when
 	 * you set the channel. Note that the libertas mesh isn't
 	 * compatible with 802.11 mesh.
 	 */
 	if (rdev->ops->libertas_set_mesh_channel) {
 		if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
 			return -EINVAL;

 		if (!netif_running(wdev->netdev))
 			return -ENETDOWN;

 		err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
 						     chandef->chan);
 		if (!err)
 			wdev->chandef = *chandef;

 		return err;
 	}

 	if (wdev->mesh_id_len)
 		return -EBUSY;

 	wdev->preset_chandef = *chandef;
 	return 0;
 }

 int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 			  struct net_device *dev)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;

 	ASSERT_WDEV_LOCK(wdev);

 	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
 		return -EOPNOTSUPP;

 	if (!rdev->ops->leave_mesh)
 		return -EOPNOTSUPP;

 	if (!wdev->mesh_id_len)
 		return -ENOTCONN;

 	err = rdev_leave_mesh(rdev, dev);
 	if (!err) {
 		wdev->conn_owner_nlportid = 0;
 		wdev->mesh_id_len = 0;
 		wdev->beacon_interval = 0;
 		memset(&wdev->chandef, 0, sizeof(wdev->chandef));
 		rdev_set_qos_map(rdev, dev, NULL);
 		cfg80211_sched_dfs_chan_update(rdev);
 	}

 	return err;
 }

 int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
 			struct net_device *dev)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	int err;

 	wdev_lock(wdev);
 	err = __cfg80211_leave_mesh(rdev, dev);
 	wdev_unlock(wdev);

 	return err;
 }
	// SPDX-License-Identifier: GPL-2.0
	#include <linux/ieee80211.h>
	#include <linux/export.h>
	#include <net/cfg80211.h>
	#include "nl80211.h"
	#include "core.h"
	#include "rdev-ops.h"

	/* Default values, timeouts in ms */
	#define MESH_TTL 31
	#define MESH_DEFAULT_ELEMENT_TTL 31
	#define MESH_MAX_RETR 3
	#define MESH_RET_T 100
	#define MESH_CONF_T 100
	#define MESH_HOLD_T 100

	#define MESH_PATH_TIMEOUT 5000
	#define MESH_RANN_INTERVAL 5000
	#define MESH_PATH_TO_ROOT_TIMEOUT 6000
	#define MESH_ROOT_INTERVAL 5000
	#define MESH_ROOT_CONFIRMATION_INTERVAL 2000
	#define MESH_DEFAULT_PLINK_TIMEOUT 1800 /* timeout in seconds */

	/*
	* Minimum interval between two consecutive PREQs originated by the same
	* interface
	*/
	#define MESH_PREQ_MIN_INT 10
	#define MESH_PERR_MIN_INT 100
	#define MESH_DIAM_TRAVERSAL_TIME 50

	#define MESH_RSSI_THRESHOLD 0

	/*
	* A path will be refreshed if it is used PATH_REFRESH_TIME milliseconds
	* before timing out. This way it will remain ACTIVE and no data frames
	* will be unnecessarily held in the pending queue.
	*/
	#define MESH_PATH_REFRESH_TIME 1000
	#define MESH_MIN_DISCOVERY_TIMEOUT (2 * MESH_DIAM_TRAVERSAL_TIME)

	/* Default maximum number of established plinks per interface */
	#define MESH_MAX_ESTAB_PLINKS 32

	#define MESH_MAX_PREQ_RETRIES 4

	#define MESH_SYNC_NEIGHBOR_OFFSET_MAX 50

	#define MESH_DEFAULT_BEACON_INTERVAL 1000 /* in 1024 us units (=TUs) */
	#define MESH_DEFAULT_DTIM_PERIOD 2
	#define MESH_DEFAULT_AWAKE_WINDOW 10 /* in 1024 us units (=TUs) */

	const struct mesh_config default_mesh_config = {
	.dot11MeshRetryTimeout = MESH_RET_T,
	.dot11MeshConfirmTimeout = MESH_CONF_T,
	.dot11MeshHoldingTimeout = MESH_HOLD_T,
	.dot11MeshMaxRetries = MESH_MAX_RETR,
	.dot11MeshTTL = MESH_TTL,
	.element_ttl = MESH_DEFAULT_ELEMENT_TTL,
	.auto_open_plinks = true,
	.dot11MeshMaxPeerLinks = MESH_MAX_ESTAB_PLINKS,
	.dot11MeshNbrOffsetMaxNeighbor = MESH_SYNC_NEIGHBOR_OFFSET_MAX,
	.dot11MeshHWMPactivePathTimeout = MESH_PATH_TIMEOUT,
	.dot11MeshHWMPpreqMinInterval = MESH_PREQ_MIN_INT,
	.dot11MeshHWMPperrMinInterval = MESH_PERR_MIN_INT,
	.dot11MeshHWMPnetDiameterTraversalTime = MESH_DIAM_TRAVERSAL_TIME,
	.dot11MeshHWMPmaxPREQretries = MESH_MAX_PREQ_RETRIES,
	.path_refresh_time = MESH_PATH_REFRESH_TIME,
	.min_discovery_timeout = MESH_MIN_DISCOVERY_TIMEOUT,
	.dot11MeshHWMPRannInterval = MESH_RANN_INTERVAL,
	.dot11MeshGateAnnouncementProtocol = false,
	.dot11MeshForwarding = true,
	.rssi_threshold = MESH_RSSI_THRESHOLD,
	.ht_opmode = IEEE80211_HT_OP_MODE_PROTECTION_NONHT_MIXED,
	.dot11MeshHWMPactivePathToRootTimeout = MESH_PATH_TO_ROOT_TIMEOUT,
	.dot11MeshHWMProotInterval = MESH_ROOT_INTERVAL,
	.dot11MeshHWMPconfirmationInterval = MESH_ROOT_CONFIRMATION_INTERVAL,
	.power_mode = NL80211_MESH_POWER_ACTIVE,
	.dot11MeshAwakeWindowDuration = MESH_DEFAULT_AWAKE_WINDOW,
	.plink_timeout = MESH_DEFAULT_PLINK_TIMEOUT,
	.dot11MeshNolearn = false,
	};

	const struct mesh_setup default_mesh_setup = {
	/* cfg80211_join_mesh() will pick a channel if needed */
	.sync_method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
	.path_sel_proto = IEEE80211_PATH_PROTOCOL_HWMP,
	.path_metric = IEEE80211_PATH_METRIC_AIRTIME,
	.auth_id = 0, /* open */
	.ie = NULL,
	.ie_len = 0,
	.is_secure = false,
	.user_mpm = false,
	.beacon_interval = MESH_DEFAULT_BEACON_INTERVAL,
	.dtim_period = MESH_DEFAULT_DTIM_PERIOD,
	};

	int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev,
	struct net_device *dev,
	struct mesh_setup *setup,
	const struct mesh_config *conf)
	{
	struct wireless_dev *wdev = dev->ieee80211_ptr;
	int err;

	BUILD_BUG_ON(IEEE80211_MAX_SSID_LEN != IEEE80211_MAX_MESH_ID_LEN);

	ASSERT_WDEV_LOCK(wdev);

	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
	return -EOPNOTSUPP;

	if (!(rdev->wiphy.flags & WIPHY_FLAG_MESH_AUTH) &&
	setup->is_secure)
	return -EOPNOTSUPP;

	if (wdev->mesh_id_len)
	return -EALREADY;

	if (!setup->mesh_id_len)
	return -EINVAL;

	if (!rdev->ops->join_mesh)
	return -EOPNOTSUPP;

	if (!setup->chandef.chan) {
	/* if no channel explicitly given, use preset channel */
	setup->chandef = wdev->preset_chandef;
	}

	if (!setup->chandef.chan) {
	/* if we don't have that either, use the first usable channel */
	enum nl80211_band band;

	for (band = 0; band < NUM_NL80211_BANDS; band++) {
	struct ieee80211_supported_band *sband;
	struct ieee80211_channel *chan;
	int i;

	sband = rdev->wiphy.bands[band];
	if (!sband)
	continue;

	for (i = 0; i < sband->n_channels; i++) {
	chan = &sband->channels[i];
	if (chan->flags & (IEEE80211_CHAN_NO_IR \|
	IEEE80211_CHAN_DISABLED \|
	IEEE80211_CHAN_RADAR))
	continue;
	setup->chandef.chan = chan;
	break;
	}

	if (setup->chandef.chan)
	break;
	}

	/* no usable channel ... */
	if (!setup->chandef.chan)
	return -EINVAL;

	setup->chandef.width = NL80211_CHAN_WIDTH_20_NOHT;
	setup->chandef.center_freq1 = setup->chandef.chan->center_freq;
	}

	/*
	* check if basic rates are available otherwise use mandatory rates as
	* basic rates
	*/
	if (!setup->basic_rates) {
	enum nl80211_bss_scan_width scan_width;
	struct ieee80211_supported_band *sband =
	rdev->wiphy.bands[setup->chandef.chan->band];

	if (setup->chandef.chan->band == NL80211_BAND_2GHZ) {
	int i;

	/*
	* Older versions selected the mandatory rates for
	* 2.4 GHz as well, but were broken in that only
	* 1 Mbps was regarded as a mandatory rate. Keep
	* using just 1 Mbps as the default basic rate for
	* mesh to be interoperable with older versions.
	*/
	for (i = 0; i < sband->n_bitrates; i++) {
	if (sband->bitrates[i].bitrate == 10) {
	setup->basic_rates = BIT(i);
	break;
	}
	}
	} else {
	scan_width = cfg80211_chandef_to_scan_width(&setup->chandef);
	setup->basic_rates = ieee80211_mandatory_rates(sband,
	scan_width);
	}
	}

	err = cfg80211_chandef_dfs_required(&rdev->wiphy,
	&setup->chandef,
	NL80211_IFTYPE_MESH_POINT);
	if (err < 0)
	return err;
	if (err > 0 && !setup->userspace_handles_dfs)
	return -EINVAL;

	if (!cfg80211_reg_can_beacon(&rdev->wiphy, &setup->chandef,
	NL80211_IFTYPE_MESH_POINT))
	return -EINVAL;

	err = rdev_join_mesh(rdev, dev, conf, setup);
	if (!err) {
	memcpy(wdev->ssid, setup->mesh_id, setup->mesh_id_len);
	wdev->mesh_id_len = setup->mesh_id_len;
	wdev->chandef = setup->chandef;
	wdev->beacon_interval = setup->beacon_interval;
	}

	return err;
	}

	int cfg80211_set_mesh_channel(struct cfg80211_registered_device *rdev,
	struct wireless_dev *wdev,
	struct cfg80211_chan_def *chandef)
	{
	int err;

	/*
	* Workaround for libertas (only!), it puts the interface
	* into mesh mode but doesn't implement join_mesh. Instead,
	* it is configured via sysfs and then joins the mesh when
	* you set the channel. Note that the libertas mesh isn't
	* compatible with 802.11 mesh.
	*/
	if (rdev->ops->libertas_set_mesh_channel) {
	if (chandef->width != NL80211_CHAN_WIDTH_20_NOHT)
	return -EINVAL;

	if (!netif_running(wdev->netdev))
	return -ENETDOWN;

	err = rdev_libertas_set_mesh_channel(rdev, wdev->netdev,
	chandef->chan);
	if (!err)
	wdev->chandef = *chandef;

	return err;
	}

	if (wdev->mesh_id_len)
	return -EBUSY;

	wdev->preset_chandef = *chandef;
	return 0;
	}

	int __cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
	struct net_device *dev)
	{
	struct wireless_dev *wdev = dev->ieee80211_ptr;
	int err;

	ASSERT_WDEV_LOCK(wdev);

	if (dev->ieee80211_ptr->iftype != NL80211_IFTYPE_MESH_POINT)
	return -EOPNOTSUPP;

	if (!rdev->ops->leave_mesh)
	return -EOPNOTSUPP;

	if (!wdev->mesh_id_len)
	return -ENOTCONN;

	err = rdev_leave_mesh(rdev, dev);
	if (!err) {
	wdev->conn_owner_nlportid = 0;
	wdev->mesh_id_len = 0;
	wdev->beacon_interval = 0;
	memset(&wdev->chandef, 0, sizeof(wdev->chandef));
	rdev_set_qos_map(rdev, dev, NULL);
	cfg80211_sched_dfs_chan_update(rdev);
	}

	return err;
	}

	int cfg80211_leave_mesh(struct cfg80211_registered_device *rdev,
	struct net_device *dev)
	{
	struct wireless_dev *wdev = dev->ieee80211_ptr;
	int err;

	wdev_lock(wdev);
	err = __cfg80211_leave_mesh(rdev, dev);
	wdev_unlock(wdev);

	return err;
	}