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: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 8049bf7..9107adc 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -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 @@
NL80211_CMD_TDLS_OPER,
NL80211_CMD_TDLS_MGMT,
+ NL80211_CMD_UNEXPECTED_FRAME,
+
/* add new commands above here */
/* used to define NL80211_CMD_MAX below */
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 0c71d4a..ef118e4 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2183,6 +2183,8 @@
int beacon_interval;
+ u32 ap_unexpected_nlpid;
+
#ifdef CONFIG_CFG80211_WEXT
/* wext data */
struct {
@@ -3193,6 +3195,21 @@
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 */
diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index 21fc970..f4d868b 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -879,6 +879,9 @@
}
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 @@
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);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 2bcaa57..9910c3c 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5832,6 +5832,23 @@
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 @@
.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 @@
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)
diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h
index f24a1fb..d94456e 100644
--- a/net/wireless/nl80211.h
+++ b/net/wireless/nl80211.h
@@ -117,4 +117,7 @@
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 */