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>

1 files changed, 66 insertions, 0 deletions

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)