Commit ed3557c9 authored by Miquel Raynal's avatar Miquel Raynal Committed by Stefan Schmidt
Browse files

ieee802154: Add support for user scanning requests 



The ieee802154 layer should be able to scan a set of channels in order
to look for beacons advertizing PANs. Supporting this involves adding
two user commands: triggering scans and aborting scans. The user should
also be notified when a new beacon is received and also upon scan
termination.

A scan request structure is created to list the requirements and to be
accessed asynchronously when changing channels or receiving beacons.

Mac layers may now implement the ->trigger_scan() and ->abort_scan()
hooks.

Co-developed-by: default avatarDavid Girault <david.girault@qorvo.com>
Signed-off-by: default avatarDavid Girault <david.girault@qorvo.com>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Acked-by: default avatarAlexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20230103165644.432209-2-miquel.raynal@bootlin.com


Signed-off-by: default avatarStefan Schmidt <stefan@datenfreihafen.org>
parent d8b879c0

include/linux/ieee802154.h

+3 −0
Original line number Diff line number Diff line
@@ -44,6 +44,9 @@ 
#define IEEE802154_SHORT_ADDR_LEN	2

#define IEEE802154_PAN_ID_LEN		2



/* Duration in superframe order */

#define IEEE802154_MAX_SCAN_DURATION	14

#define IEEE802154_ACTIVE_SCAN_DURATION	15

#define IEEE802154_LIFS_PERIOD		40

#define IEEE802154_SIFS_PERIOD		12

#define IEEE802154_MAX_SIFS_FRAME_SIZE	18

include/net/cfg802154.h

+25 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 


struct wpan_phy;

struct wpan_phy_cca;

struct cfg802154_scan_request;



#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL

struct ieee802154_llsec_device_key;
@@ -67,6 +68,10 @@ struct cfg802154_ops { 
				struct wpan_dev *wpan_dev, bool mode);

	int	(*set_ackreq_default)(struct wpan_phy *wpan_phy,

				      struct wpan_dev *wpan_dev, bool ackreq);

	int	(*trigger_scan)(struct wpan_phy *wpan_phy,

				struct cfg802154_scan_request *request);

	int	(*abort_scan)(struct wpan_phy *wpan_phy,

			      struct wpan_dev *wpan_dev);

#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL

	void	(*get_llsec_table)(struct wpan_phy *wpan_phy,

				   struct wpan_dev *wpan_dev,
@@ -278,6 +283,26 @@ struct ieee802154_coord_desc { 
	bool gts_permit;

};



/**

 * struct cfg802154_scan_request - Scan request

 *

 * @type: type of scan to be performed

 * @page: page on which to perform the scan

 * @channels: channels in te %page to be scanned

 * @duration: time spent on each channel, calculated with:

 *            aBaseSuperframeDuration * (2 ^ duration + 1)

 * @wpan_dev: the wpan device on which to perform the scan

 * @wpan_phy: the wpan phy on which to perform the scan

 */

struct cfg802154_scan_request {

	enum nl802154_scan_types type;

	u8 page;

	u32 channels;

	u8 duration;

	struct wpan_dev *wpan_dev;

	struct wpan_phy *wpan_phy;

};



struct ieee802154_llsec_key_id {

	u8 mode;

	u8 id;

include/net/nl802154.h

+58 −0
Original line number Diff line number Diff line
@@ -73,6 +73,9 @@ enum nl802154_commands { 
	NL802154_CMD_DEL_SEC_LEVEL,



	NL802154_CMD_SCAN_EVENT,

	NL802154_CMD_TRIGGER_SCAN,

	NL802154_CMD_ABORT_SCAN,

	NL802154_CMD_SCAN_DONE,



	/* add new commands above here */
@@ -134,6 +137,13 @@ enum nl802154_attrs { 
	NL802154_ATTR_NETNS_FD,



	NL802154_ATTR_COORDINATOR,

	NL802154_ATTR_SCAN_TYPE,

	NL802154_ATTR_SCAN_FLAGS,

	NL802154_ATTR_SCAN_CHANNELS,

	NL802154_ATTR_SCAN_PREAMBLE_CODES,

	NL802154_ATTR_SCAN_MEAN_PRF,

	NL802154_ATTR_SCAN_DURATION,

	NL802154_ATTR_SCAN_DONE_REASON,



	/* add attributes here, update the policy in nl802154.c */
@@ -259,6 +269,54 @@ enum nl802154_coord { 
	NL802154_COORD_MAX,

};



/**

 * enum nl802154_scan_types - Scan types

 *

 * @__NL802154_SCAN_INVALID: scan type number 0 is reserved

 * @NL802154_SCAN_ED: An ED scan allows a device to obtain a measure of the peak

 *	energy in each requested channel

 * @NL802154_SCAN_ACTIVE: Locate any coordinator transmitting Beacon frames using

 *	a Beacon Request command

 * @NL802154_SCAN_PASSIVE: Locate any coordinator transmitting Beacon frames

 * @NL802154_SCAN_ORPHAN: Relocate coordinator following a loss of synchronisation

 * @NL802154_SCAN_ENHANCED_ACTIVE: Same as Active using Enhanced Beacon Request

 *	command instead of Beacon Request command

 * @NL802154_SCAN_RIT_PASSIVE: Passive scan for RIT Data Request command frames

 *	instead of Beacon frames

 * @NL802154_SCAN_ATTR_MAX: Maximum SCAN attribute number

 */

enum nl802154_scan_types {

	__NL802154_SCAN_INVALID,

	NL802154_SCAN_ED,

	NL802154_SCAN_ACTIVE,

	NL802154_SCAN_PASSIVE,

	NL802154_SCAN_ORPHAN,

	NL802154_SCAN_ENHANCED_ACTIVE,

	NL802154_SCAN_RIT_PASSIVE,



	/* keep last */

	NL802154_SCAN_ATTR_MAX,

};



/**

 * enum nl802154_scan_done_reasons - End of scan reasons

 *

 * @__NL802154_SCAN_DONE_REASON_INVALID: scan done reason number 0 is reserved.

 * @NL802154_SCAN_DONE_REASON_FINISHED: The scan just finished naturally after

 *	going through all the requested and possible (complex) channels.

 * @NL802154_SCAN_DONE_REASON_ABORTED: The scan was aborted upon user request.

 *	a Beacon Request command

 * @NL802154_SCAN_DONE_REASON_MAX: Maximum scan done reason attribute number.

 */

enum nl802154_scan_done_reasons {

	__NL802154_SCAN_DONE_REASON_INVALID,

	NL802154_SCAN_DONE_REASON_FINISHED,

	NL802154_SCAN_DONE_REASON_ABORTED,



	/* keep last */

	NL802154_SCAN_DONE_REASON_MAX,

};



/**

 * enum nl802154_cca_modes - cca modes

 *

net/ieee802154/nl802154.c

+220 −0
Original line number Diff line number Diff line
@@ -221,6 +221,13 @@ static const struct nla_policy nl802154_policy[NL802154_ATTR_MAX+1] = { 


	[NL802154_ATTR_COORDINATOR] = { .type = NLA_NESTED },



	[NL802154_ATTR_SCAN_TYPE] = { .type = NLA_U8 },

	[NL802154_ATTR_SCAN_CHANNELS] = { .type = NLA_U32 },

	[NL802154_ATTR_SCAN_PREAMBLE_CODES] = { .type = NLA_U64 },

	[NL802154_ATTR_SCAN_MEAN_PRF] = { .type = NLA_U8 },

	[NL802154_ATTR_SCAN_DURATION] = { .type = NLA_U8 },

	[NL802154_ATTR_SCAN_DONE_REASON] = { .type = NLA_U8 },



#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL

	[NL802154_ATTR_SEC_ENABLED] = { .type = NLA_U8, },

	[NL802154_ATTR_SEC_OUT_LEVEL] = { .type = NLA_U32, },
@@ -1384,6 +1391,203 @@ int nl802154_scan_event(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev, 
}

EXPORT_SYMBOL_GPL(nl802154_scan_event);



static int nl802154_trigger_scan(struct sk_buff *skb, struct genl_info *info)

{

	struct cfg802154_registered_device *rdev = info->user_ptr[0];

	struct net_device *dev = info->user_ptr[1];

	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;

	struct wpan_phy *wpan_phy = &rdev->wpan_phy;

	struct cfg802154_scan_request *request;

	u8 type;

	int err;



	/* Monitors are not allowed to perform scans */

	if (wpan_dev->iftype == NL802154_IFTYPE_MONITOR)

		return -EPERM;



	request = kzalloc(sizeof(*request), GFP_KERNEL);

	if (!request)

		return -ENOMEM;



	request->wpan_dev = wpan_dev;

	request->wpan_phy = wpan_phy;



	type = nla_get_u8(info->attrs[NL802154_ATTR_SCAN_TYPE]);

	switch (type) {

	case NL802154_SCAN_PASSIVE:

		request->type = type;

		break;

	default:

		pr_err("Unsupported scan type: %d\n", type);

		err = -EINVAL;

		goto free_request;

	}



	if (info->attrs[NL802154_ATTR_PAGE]) {

		request->page = nla_get_u8(info->attrs[NL802154_ATTR_PAGE]);

		if (request->page > IEEE802154_MAX_PAGE) {

			pr_err("Invalid page %d > %d\n",

			       request->page, IEEE802154_MAX_PAGE);

			err = -EINVAL;

			goto free_request;

		}

	} else {

		/* Use current page by default */

		request->page = wpan_phy->current_page;

	}



	if (info->attrs[NL802154_ATTR_SCAN_CHANNELS]) {

		request->channels = nla_get_u32(info->attrs[NL802154_ATTR_SCAN_CHANNELS]);

		if (request->channels >= BIT(IEEE802154_MAX_CHANNEL + 1)) {

			pr_err("Invalid channels bitfield %x ≥ %lx\n",

			       request->channels,

			       BIT(IEEE802154_MAX_CHANNEL + 1));

			err = -EINVAL;

			goto free_request;

		}

	} else {

		/* Scan all supported channels by default */

		request->channels = wpan_phy->supported.channels[request->page];

	}



	if (info->attrs[NL802154_ATTR_SCAN_PREAMBLE_CODES] ||

	    info->attrs[NL802154_ATTR_SCAN_MEAN_PRF]) {

		pr_err("Preamble codes and mean PRF not supported yet\n");

		err = -EINVAL;

		goto free_request;

	}



	if (info->attrs[NL802154_ATTR_SCAN_DURATION]) {

		request->duration = nla_get_u8(info->attrs[NL802154_ATTR_SCAN_DURATION]);

		if (request->duration > IEEE802154_MAX_SCAN_DURATION) {

			pr_err("Duration is out of range\n");

			err = -EINVAL;

			goto free_request;

		}

	} else {

		/* Use maximum duration order by default */

		request->duration = IEEE802154_MAX_SCAN_DURATION;

	}



	if (wpan_dev->netdev)

		dev_hold(wpan_dev->netdev);



	err = rdev_trigger_scan(rdev, request);

	if (err) {

		pr_err("Failure starting scanning (%d)\n", err);

		goto free_device;

	}



	return 0;



free_device:

	if (wpan_dev->netdev)

		dev_put(wpan_dev->netdev);

free_request:

	kfree(request);



	return err;

}



static int nl802154_prep_scan_msg(struct sk_buff *msg,

				  struct cfg802154_registered_device *rdev,

				  struct wpan_dev *wpan_dev, u32 portid,

				  u32 seq, int flags, u8 cmd, u8 arg)

{

	void *hdr;



	hdr = nl802154hdr_put(msg, portid, seq, flags, cmd);

	if (!hdr)

		return -ENOBUFS;



	if (nla_put_u32(msg, NL802154_ATTR_WPAN_PHY, rdev->wpan_phy_idx))

		goto nla_put_failure;



	if (wpan_dev->netdev &&

	    nla_put_u32(msg, NL802154_ATTR_IFINDEX, wpan_dev->netdev->ifindex))

		goto nla_put_failure;



	if (nla_put_u64_64bit(msg, NL802154_ATTR_WPAN_DEV,

			      wpan_dev_id(wpan_dev), NL802154_ATTR_PAD))

		goto nla_put_failure;



	if (cmd == NL802154_CMD_SCAN_DONE &&

	    nla_put_u8(msg, NL802154_ATTR_SCAN_DONE_REASON, arg))

		goto nla_put_failure;



	genlmsg_end(msg, hdr);



	return 0;



nla_put_failure:

	genlmsg_cancel(msg, hdr);



	return -EMSGSIZE;

}



static int nl802154_send_scan_msg(struct cfg802154_registered_device *rdev,

				  struct wpan_dev *wpan_dev, u8 cmd, u8 arg)

{

	struct sk_buff *msg;

	int ret;



	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

	if (!msg)

		return -ENOMEM;



	ret = nl802154_prep_scan_msg(msg, rdev, wpan_dev, 0, 0, 0, cmd, arg);

	if (ret < 0) {

		nlmsg_free(msg);

		return ret;

	}



	return genlmsg_multicast_netns(&nl802154_fam,

				       wpan_phy_net(&rdev->wpan_phy), msg, 0,

				       NL802154_MCGRP_SCAN, GFP_KERNEL);

}



int nl802154_scan_started(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev)

{

	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(wpan_phy);

	int err;



	/* Ignore errors when there are no listeners */

	err = nl802154_send_scan_msg(rdev, wpan_dev, NL802154_CMD_TRIGGER_SCAN, 0);

	if (err == -ESRCH)

		err = 0;



	return err;

}

EXPORT_SYMBOL_GPL(nl802154_scan_started);



int nl802154_scan_done(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev,

		       enum nl802154_scan_done_reasons reason)

{

	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(wpan_phy);

	int err;



	/* Ignore errors when there are no listeners */

	err = nl802154_send_scan_msg(rdev, wpan_dev, NL802154_CMD_SCAN_DONE, reason);

	if (err == -ESRCH)

		err = 0;



	if (wpan_dev->netdev)

		dev_put(wpan_dev->netdev);



	return err;

}

EXPORT_SYMBOL_GPL(nl802154_scan_done);



static int nl802154_abort_scan(struct sk_buff *skb, struct genl_info *info)

{

	struct cfg802154_registered_device *rdev = info->user_ptr[0];

	struct net_device *dev = info->user_ptr[1];

	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;



	/* Resources are released in the notification helper above */

	return rdev_abort_scan(rdev, wpan_dev);

}



#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL

static const struct nla_policy nl802154_dev_addr_policy[NL802154_DEV_ADDR_ATTR_MAX + 1] = {

	[NL802154_DEV_ADDR_ATTR_PAN_ID] = { .type = NLA_U16 },
@@ -2474,6 +2678,22 @@ static const struct genl_ops nl802154_ops[] = { 
		.internal_flags = NL802154_FLAG_NEED_NETDEV |

				  NL802154_FLAG_NEED_RTNL,

	},

	{

		.cmd = NL802154_CMD_TRIGGER_SCAN,

		.doit = nl802154_trigger_scan,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL802154_FLAG_NEED_NETDEV |

				  NL802154_FLAG_CHECK_NETDEV_UP |

				  NL802154_FLAG_NEED_RTNL,

	},

	{

		.cmd = NL802154_CMD_ABORT_SCAN,

		.doit = nl802154_abort_scan,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL802154_FLAG_NEED_NETDEV |

				  NL802154_FLAG_CHECK_NETDEV_UP |

				  NL802154_FLAG_NEED_RTNL,

	},

#ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL

	{

		.cmd = NL802154_CMD_SET_SEC_PARAMS,

net/ieee802154/nl802154.h

+3 −0
Original line number Diff line number Diff line
@@ -6,5 +6,8 @@ int nl802154_init(void); 
void nl802154_exit(void);

int nl802154_scan_event(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev,

			struct ieee802154_coord_desc *desc);

int nl802154_scan_started(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev);

int nl802154_scan_done(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev,

		       enum nl802154_scan_done_reasons reason);



#endif /* __IEEE802154_NL802154_H */