Commit 28946da7 authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
Browse files

nl80211: allow subscribing to unexpected class3 frames 



To implement AP mode without monitor interfaces we
need to be able to send a deauth to stations that
send frames without being associated. Enable this
by adding a new nl80211 event for such frames that
an application can subscribe to.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 665c93a9

include/linux/nl80211.h

+12 −0
Original line number Diff line number Diff line
@@ -509,6 +509,16 @@ 
 * @NL80211_CMD_TDLS_OPER: Perform a high-level TDLS command (e.g. link setup).

 * @NL80211_CMD_TDLS_MGMT: Send a TDLS management frame.

 *

 * @NL80211_CMD_UNEXPECTED_FRAME: Used by an application controlling an AP

 *	(or GO) interface (i.e. hostapd) to ask for unexpected frames to

 *	implement sending deauth to stations that send unexpected class 3

 *	frames. Also used as the event sent by the kernel when such a frame

 *	is received.

 *	For the event, the %NL80211_ATTR_MAC attribute carries the TA and

 *	other attributes like the interface index are present.

 *	If used as the command it must have an interface index and you can

 *	only unsubscribe from the event by closing the socket.

 *

 * @NL80211_CMD_MAX: highest used command number

 * @__NL80211_CMD_AFTER_LAST: internal use

 */
@@ -638,6 +648,8 @@ enum nl80211_commands { 
	NL80211_CMD_TDLS_OPER,

	NL80211_CMD_TDLS_MGMT,



	NL80211_CMD_UNEXPECTED_FRAME,



	/* add new commands above here */



	/* used to define NL80211_CMD_MAX below */

include/net/cfg80211.h

+17 −0
Original line number Diff line number Diff line
@@ -2183,6 +2183,8 @@ struct wireless_dev { 


	int beacon_interval;



	u32 ap_unexpected_nlpid;



#ifdef CONFIG_CFG80211_WEXT

	/* wext data */

	struct {
@@ -3193,6 +3195,21 @@ void cfg80211_gtk_rekey_notify(struct net_device *dev, const u8 *bssid, 
void cfg80211_pmksa_candidate_notify(struct net_device *dev, int index,

				     const u8 *bssid, bool preauth, gfp_t gfp);



/**

 * cfg80211_rx_spurious_frame - inform userspace about a spurious frame

 * @dev: The device the frame matched to

 * @addr: the transmitter address

 * @gfp: context flags

 *

 * This function is used in AP mode (only!) to inform userspace that

 * a spurious class 3 frame was received, to be able to deauth the

 * sender.

 * Returns %true if the frame was passed to userspace (or this failed

 * for a reason other than not having a subscription.)

 */

bool cfg80211_rx_spurious_frame(struct net_device *dev,

				const u8 *addr, gfp_t gfp);



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



/* wiphy_printk helpers, similar to dev_printk */

net/wireless/mlme.c

+16 −0
Original line number Diff line number Diff line
@@ -879,6 +879,9 @@ void cfg80211_mlme_unregister_socket(struct wireless_dev *wdev, u32 nlpid) 
	}



	spin_unlock_bh(&wdev->mgmt_registrations_lock);



	if (nlpid == wdev->ap_unexpected_nlpid)

		wdev->ap_unexpected_nlpid = 0;

}



void cfg80211_mlme_purge_registrations(struct wireless_dev *wdev)
@@ -1107,3 +1110,16 @@ void cfg80211_pmksa_candidate_notify(struct net_device *dev, int index, 
	nl80211_pmksa_candidate_notify(rdev, dev, index, bssid, preauth, gfp);

}

EXPORT_SYMBOL(cfg80211_pmksa_candidate_notify);



bool cfg80211_rx_spurious_frame(struct net_device *dev,

				const u8 *addr, gfp_t gfp)

{

	struct wireless_dev *wdev = dev->ieee80211_ptr;



	if (WARN_ON(wdev->iftype != NL80211_IFTYPE_AP &&

		    wdev->iftype != NL80211_IFTYPE_P2P_GO))

		return false;



	return nl80211_unexpected_frame(dev, addr, gfp);

}

EXPORT_SYMBOL(cfg80211_rx_spurious_frame);

net/wireless/nl80211.c

+66 −0
Original line number Diff line number Diff line
@@ -5832,6 +5832,23 @@ static int nl80211_set_rekey_data(struct sk_buff *skb, struct genl_info *info) 
	return err;

}



static int nl80211_register_unexpected_frame(struct sk_buff *skb,

					     struct genl_info *info)

{

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

	struct wireless_dev *wdev = dev->ieee80211_ptr;



	if (wdev->iftype != NL80211_IFTYPE_AP &&

	    wdev->iftype != NL80211_IFTYPE_P2P_GO)

		return -EINVAL;



	if (wdev->ap_unexpected_nlpid)

		return -EBUSY;



	wdev->ap_unexpected_nlpid = info->snd_pid;

	return 0;

}



#define NL80211_FLAG_NEED_WIPHY		0x01

#define NL80211_FLAG_NEED_NETDEV	0x02

#define NL80211_FLAG_NEED_RTNL		0x04
@@ -6387,6 +6404,14 @@ static struct genl_ops nl80211_ops[] = { 
		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |

				  NL80211_FLAG_NEED_RTNL,

	},

	{

		.cmd = NL80211_CMD_UNEXPECTED_FRAME,

		.doit = nl80211_register_unexpected_frame,

		.policy = nl80211_policy,

		.flags = GENL_ADMIN_PERM,

		.internal_flags = NL80211_FLAG_NEED_NETDEV |

				  NL80211_FLAG_NEED_RTNL,

	},

};



static struct genl_multicast_group nl80211_mlme_mcgrp = {
@@ -7171,6 +7196,47 @@ void nl80211_send_sta_del_event(struct cfg80211_registered_device *rdev, 
	nlmsg_free(msg);

}



bool nl80211_unexpected_frame(struct net_device *dev, const u8 *addr, gfp_t gfp)

{

	struct wireless_dev *wdev = dev->ieee80211_ptr;

	struct cfg80211_registered_device *rdev = wiphy_to_dev(wdev->wiphy);

	struct sk_buff *msg;

	void *hdr;

	int err;

	u32 nlpid = ACCESS_ONCE(wdev->ap_unexpected_nlpid);



	if (!nlpid)

		return false;



	msg = nlmsg_new(100, gfp);

	if (!msg)

		return true;



	hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_UNEXPECTED_FRAME);

	if (!hdr) {

		nlmsg_free(msg);

		return true;

	}



	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx);

	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);

	NLA_PUT(msg, NL80211_ATTR_MAC, ETH_ALEN, addr);



	err = genlmsg_end(msg, hdr);

	if (err < 0) {

		nlmsg_free(msg);

		return true;

	}



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

	return true;



 nla_put_failure:

	genlmsg_cancel(msg, hdr);

	nlmsg_free(msg);

	return true;

}



int nl80211_send_mgmt(struct cfg80211_registered_device *rdev,

		      struct net_device *netdev, u32 nlpid,

		      int freq, const u8 *buf, size_t len, gfp_t gfp)

net/wireless/nl80211.h

+3 −0
Original line number Diff line number Diff line
@@ -117,4 +117,7 @@ void nl80211_pmksa_candidate_notify(struct cfg80211_registered_device *rdev, 
				    struct net_device *netdev, int index,

				    const u8 *bssid, bool preauth, gfp_t gfp);



bool nl80211_unexpected_frame(struct net_device *dev,

			      const u8 *addr, gfp_t gfp);



#endif /* __NET_WIRELESS_NL80211_H */