From 28946da763e8b8d8ffd01ab861b684a4afb4bc3b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Fri, 4 Nov 2011 11:18:12 +0100 Subject: [PATCH] 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 Signed-off-by: John W. Linville --- include/linux/nl80211.h | 12 ++++++++ include/net/cfg80211.h | 17 +++++++++++ net/wireless/mlme.c | 16 ++++++++++ net/wireless/nl80211.c | 66 +++++++++++++++++++++++++++++++++++++++++ net/wireless/nl80211.h | 3 ++ 5 files changed, 114 insertions(+) diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h index 8049bf77d799..9107adc73e0b 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 @@ 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 */ diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 0c71d4a30cd6..ef118e452589 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -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 */ diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c index 21fc9702f81c..f4d868b1e11c 100644 --- a/net/wireless/mlme.c +++ b/net/wireless/mlme.c @@ -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); diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 2bcaa579cebf..9910c3cb9a85 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -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) diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h index f24a1fbeaf19..d94456e54f4e 100644 --- a/net/wireless/nl80211.h +++ b/net/wireless/nl80211.h @@ -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 */ -- 2.39.5