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Commit 5de17984 authored by Arend van Spriel's avatar Arend van Spriel Committed by Johannes Berg
Browse files

cfg80211: introduce critical protocol indication from user-space 



Some protocols need a more reliable connection to complete
successful in reasonable time. This patch adds a user-space
API to indicate the wireless driver that a critical protocol
is about to commence and when it is done, using nl80211 primitives
NL80211_CMD_CRIT_PROTOCOL_START and NL80211_CRIT_PROTOCOL_STOP.

There can be only on critical protocol session started per
registered cfg80211 device.

The driver can support this by implementing the cfg80211 callbacks
.crit_proto_start() and .crit_proto_stop(). Examples of protocols
that can benefit from this are DHCP, EAPOL, APIPA. Exactly how the
link can/should be made more reliable is up to the driver. Things
to consider are avoid scanning, no multi-channel operations, and
alter coexistence schemes.

Reviewed-by: default avatarPieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: default avatarFranky (Zhenhui) Lin <frankyl@broadcom.com>
Signed-off-by: default avatarArend van Spriel <arend@broadcom.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent a3647362

include/net/cfg80211.h

+23 −0
Original line number Diff line number Diff line
@@ -2002,6 +2002,12 @@ struct cfg80211_update_ft_ies_params { 
 * @update_ft_ies: Provide updated Fast BSS Transition information to the

 *	driver. If the SME is in the driver/firmware, this information can be

 *	used in building Authentication and Reassociation Request frames.

 *

 * @crit_proto_start: Indicates a critical protocol needs more link reliability

 *	for a given duration (milliseconds). The protocol is provided so the

 *	driver can take the most appropriate actions.

 * @crit_proto_stop: Indicates critical protocol no longer needs increased link

 *	reliability. This operation can not fail.

 */

struct cfg80211_ops {

	int	(*suspend)(struct wiphy *wiphy, struct cfg80211_wowlan *wow);
@@ -2231,6 +2237,12 @@ struct cfg80211_ops { 
					 struct cfg80211_chan_def *chandef);

	int	(*update_ft_ies)(struct wiphy *wiphy, struct net_device *dev,

				 struct cfg80211_update_ft_ies_params *ftie);

	int	(*crit_proto_start)(struct wiphy *wiphy,

				    struct wireless_dev *wdev,

				    enum nl80211_crit_proto_id protocol,

				    u16 duration);

	void	(*crit_proto_stop)(struct wiphy *wiphy,

				   struct wireless_dev *wdev);

};



/*
@@ -4137,6 +4149,17 @@ void cfg80211_report_wowlan_wakeup(struct wireless_dev *wdev, 
				   struct cfg80211_wowlan_wakeup *wakeup,

				   gfp_t gfp);



/**

 * cfg80211_crit_proto_stopped() - indicate critical protocol stopped by driver.

 *

 * @wdev: the wireless device for which critical protocol is stopped.

 *

 * This function can be called by the driver to indicate it has reverted

 * operation back to normal. One reason could be that the duration given

 * by .crit_proto_start() has expired.

 */

void cfg80211_crit_proto_stopped(struct wireless_dev *wdev, gfp_t gfp);



/* Logging, debugging and troubleshooting/diagnostic helpers. */



/* wiphy_printk helpers, similar to dev_printk */

include/uapi/linux/nl80211.h

+39 −0
Original line number Diff line number Diff line
@@ -639,6 +639,13 @@ 
 *	with the relevant Information Elements. This event is used to report

 *	received FT IEs (MDIE, FTIE, RSN IE, TIE, RICIE).

 *

 * @NL80211_CMD_CRIT_PROTOCOL_START: Indicates user-space will start running

 *	a critical protocol that needs more reliability in the connection to

 *	complete.

 *

 * @NL80211_CMD_CRIT_PROTOCOL_STOP: Indicates the connection reliability can

 *	return back to normal.

 *

 * @NL80211_CMD_MAX: highest used command number

 * @__NL80211_CMD_AFTER_LAST: internal use

 */
@@ -798,6 +805,9 @@ enum nl80211_commands { 
	NL80211_CMD_UPDATE_FT_IES,

	NL80211_CMD_FT_EVENT,



	NL80211_CMD_CRIT_PROTOCOL_START,

	NL80211_CMD_CRIT_PROTOCOL_STOP,



	/* add new commands above here */



	/* used to define NL80211_CMD_MAX below */
@@ -1414,6 +1424,11 @@ enum nl80211_commands { 
 * @NL80211_ATTR_IE_RIC: Resource Information Container Information

 *	Element

 *

 * @NL80211_ATTR_CRIT_PROT_ID: critical protocol identifier requiring increased

 *	reliability, see &enum nl80211_crit_proto_id (u16).

 * @NL80211_ATTR_MAX_CRIT_PROT_DURATION: duration in milliseconds in which

 *      the connection should have increased reliability (u16).

 *

 * @NL80211_ATTR_MAX: highest attribute number currently defined

 * @__NL80211_ATTR_AFTER_LAST: internal use

 */
@@ -1709,6 +1724,9 @@ enum nl80211_attrs { 
	NL80211_ATTR_MDID,

	NL80211_ATTR_IE_RIC,



	NL80211_ATTR_CRIT_PROT_ID,

	NL80211_ATTR_MAX_CRIT_PROT_DURATION,



	/* add attributes here, update the policy in nl80211.c */



	__NL80211_ATTR_AFTER_LAST,
@@ -3682,4 +3700,25 @@ enum nl80211_protocol_features { 
	NL80211_PROTOCOL_FEATURE_SPLIT_WIPHY_DUMP =	1 << 0,

};



/**

 * enum nl80211_crit_proto_id - nl80211 critical protocol identifiers

 *

 * @NL80211_CRIT_PROTO_UNSPEC: protocol unspecified.

 * @NL80211_CRIT_PROTO_DHCP: BOOTP or DHCPv6 protocol.

 * @NL80211_CRIT_PROTO_EAPOL: EAPOL protocol.

 * @NL80211_CRIT_PROTO_APIPA: APIPA protocol.

 * @NUM_NL80211_CRIT_PROTO: must be kept last.

 */

enum nl80211_crit_proto_id {

	NL80211_CRIT_PROTO_UNSPEC,

	NL80211_CRIT_PROTO_DHCP,

	NL80211_CRIT_PROTO_EAPOL,

	NL80211_CRIT_PROTO_APIPA,

	/* add other protocols before this one */

	NUM_NL80211_CRIT_PROTO

};



/* maximum duration for critical protocol measures */

#define NL80211_CRIT_PROTO_MAX_DURATION		5000 /* msec */



#endif /* __LINUX_NL80211_H */

net/wireless/core.h

+3 −0
Original line number Diff line number Diff line
@@ -88,6 +88,9 @@ struct cfg80211_registered_device { 


	struct delayed_work dfs_update_channels_wk;



	/* netlink port which started critical protocol (0 means not started) */

	u32 crit_proto_nlportid;



	/* must be last because of the way we do wiphy_priv(),

	 * and it should at least be aligned to NETDEV_ALIGN */

	struct wiphy wiphy __aligned(NETDEV_ALIGN);

net/wireless/mlme.c

+5 −0
Original line number Diff line number Diff line
@@ -648,6 +648,11 @@ void cfg80211_mlme_unregister_socket(struct wireless_dev *wdev, u32 nlportid) 


	spin_unlock_bh(&wdev->mgmt_registrations_lock);



	if (nlportid && rdev->crit_proto_nlportid == nlportid) {

		rdev->crit_proto_nlportid = 0;

		rdev_crit_proto_stop(rdev, wdev);

	}



	if (nlportid == wdev->ap_unexpected_nlportid)

		wdev->ap_unexpected_nlportid = 0;

}

net/wireless/nl80211.c

+117 −0
Original line number Diff line number Diff line
@@ -1424,6 +1424,10 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *dev, 
		}

		CMD(start_p2p_device, START_P2P_DEVICE);

		CMD(set_mcast_rate, SET_MCAST_RATE);

		if (split) {

			CMD(crit_proto_start, CRIT_PROTOCOL_START);

			CMD(crit_proto_stop, CRIT_PROTOCOL_STOP);

		}



#ifdef CONFIG_NL80211_TESTMODE

		CMD(testmode_cmd, TESTMODE);
@@ -8216,6 +8220,64 @@ static int nl80211_update_ft_ies(struct sk_buff *skb, struct genl_info *info) 
	return rdev_update_ft_ies(rdev, dev, &ft_params);

}



static int nl80211_crit_protocol_start(struct sk_buff *skb,

				       struct genl_info *info)

{

	struct cfg80211_registered_device *rdev = info->user_ptr[0];

	struct wireless_dev *wdev = info->user_ptr[1];

	enum nl80211_crit_proto_id proto = NL80211_CRIT_PROTO_UNSPEC;

	u16 duration;

	int ret;



	if (!rdev->ops->crit_proto_start)

		return -EOPNOTSUPP;



	if (WARN_ON(!rdev->ops->crit_proto_stop))

		return -EINVAL;



	if (rdev->crit_proto_nlportid)

		return -EBUSY;



	/* determine protocol if provided */

	if (info->attrs[NL80211_ATTR_CRIT_PROT_ID])

		proto = nla_get_u16(info->attrs[NL80211_ATTR_CRIT_PROT_ID]);



	if (proto >= NUM_NL80211_CRIT_PROTO)

		return -EINVAL;



	/* timeout must be provided */

	if (!info->attrs[NL80211_ATTR_MAX_CRIT_PROT_DURATION])

		return -EINVAL;



	duration =

		nla_get_u16(info->attrs[NL80211_ATTR_MAX_CRIT_PROT_DURATION]);



	if (duration > NL80211_CRIT_PROTO_MAX_DURATION)

		return -ERANGE;



	ret = rdev_crit_proto_start(rdev, wdev, proto, duration);

	if (!ret)

		rdev->crit_proto_nlportid = info->snd_portid;



	return ret;

}



static int nl80211_crit_protocol_stop(struct sk_buff *skb,

				      struct genl_info *info)

{

	struct cfg80211_registered_device *rdev = info->user_ptr[0];

	struct wireless_dev *wdev = info->user_ptr[1];



	if (!rdev->ops->crit_proto_stop)

		return -EOPNOTSUPP;



	if (rdev->crit_proto_nlportid) {

		rdev->crit_proto_nlportid = 0;

		rdev_crit_proto_stop(rdev, wdev);

	}

	return 0;

}



#define NL80211_FLAG_NEED_WIPHY		0x01

#define NL80211_FLAG_NEED_NETDEV	0x02

#define NL80211_FLAG_NEED_RTNL		0x04
@@ -8905,6 +8967,22 @@ static struct genl_ops nl80211_ops[] = { 
		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |

				  NL80211_FLAG_NEED_RTNL,

	},

	{

		.cmd = NL80211_CMD_CRIT_PROTOCOL_START,

		.doit = nl80211_crit_protocol_start,

		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL80211_FLAG_NEED_WDEV_UP |

				  NL80211_FLAG_NEED_RTNL,

	},

	{

		.cmd = NL80211_CMD_CRIT_PROTOCOL_STOP,

		.doit = nl80211_crit_protocol_stop,

		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL80211_FLAG_NEED_WDEV_UP |

				  NL80211_FLAG_NEED_RTNL,

	}

};



static struct genl_multicast_group nl80211_mlme_mcgrp = {
@@ -10650,6 +10728,45 @@ void cfg80211_ft_event(struct net_device *netdev, 
}

EXPORT_SYMBOL(cfg80211_ft_event);



void cfg80211_crit_proto_stopped(struct wireless_dev *wdev, gfp_t gfp)

{

	struct cfg80211_registered_device *rdev;

	struct sk_buff *msg;

	void *hdr;

	u32 nlportid;



	rdev = wiphy_to_dev(wdev->wiphy);

	if (!rdev->crit_proto_nlportid)

		return;



	nlportid = rdev->crit_proto_nlportid;

	rdev->crit_proto_nlportid = 0;



	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);

	if (!msg)

		return;



	hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_CRIT_PROTOCOL_STOP);

	if (!hdr)

		goto nla_put_failure;



	if (nla_put_u32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx) ||

	    nla_put_u64(msg, NL80211_ATTR_WDEV, wdev_id(wdev)))

		goto nla_put_failure;



	genlmsg_end(msg, hdr);



	genlmsg_unicast(wiphy_net(&rdev->wiphy), msg, nlportid);

	return;



 nla_put_failure:

	if (hdr)

		genlmsg_cancel(msg, hdr);

	nlmsg_free(msg);



}

EXPORT_SYMBOL(cfg80211_crit_proto_stopped);



/* initialisation/exit functions */



int nl80211_init(void)