4 files changed, 98 insertions, 1 deletions

diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 901a70d327d1..c29a284c27e6 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -527,6 +527,11 @@
  *      up the event with the request. The event includes the same data and
  *      has %NL80211_ATTR_ACK set if the frame was ACKed.
  *
+ * @NL80211_CMD_REGISTER_BEACONS: Register this socket to receive beacons from
+ *      other BSSes when any interfaces are in AP mode. This helps implement
+ *      OLBC handling in hostapd. Beacons are reported in %NL80211_CMD_FRAME
+ *      messages. Note that per PHY only one application may register.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -660,6 +665,8 @@ enum nl80211_commands {
 
         NL80211_CMD_PROBE_CLIENT,
 
+        NL80211_CMD_REGISTER_BEACONS,
+
         /* 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 389e85e8c03d..d01307f54faa 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1686,6 +1686,9 @@ struct cfg80211_ops {
  *      command. When this flag is not set, @NL80211_CMD_TDLS_OPER should be
  *      used for asking the driver/firmware to perform a TDLS operation.
  * @WIPHY_FLAG_HAVE_AP_SME: device integrates AP SME
+ * @WIPHY_FLAG_REPORTS_OBSS: the device will report beacons from other BSSes
+ *      when there are virtual interfaces in AP mode by calling
+ *      cfg80211_report_obss_beacon().
  */
 enum wiphy_flags {
         WIPHY_FLAG_CUSTOM_REGULATORY            = BIT(0),
@@ -1705,6 +1708,7 @@ enum wiphy_flags {
         WIPHY_FLAG_SUPPORTS_TDLS                = BIT(15),
         WIPHY_FLAG_TDLS_EXTERNAL_SETUP          = BIT(16),
         WIPHY_FLAG_HAVE_AP_SME                  = BIT(17),
+        WIPHY_FLAG_REPORTS_OBSS                 = BIT(18),
 };
 
 /**
@@ -3233,6 +3237,22 @@ bool cfg80211_rx_spurious_frame(struct net_device *dev,
 void cfg80211_probe_status(struct net_device *dev, const u8 *addr,
                            u64 cookie, bool acked, gfp_t gfp);
 
+/**
+ * cfg80211_report_obss_beacon - report beacon from other APs
+ * @wiphy: The wiphy that received the beacon
+ * @frame: the frame
+ * @len: length of the frame
+ * @freq: frequency the frame was received on
+ * @gfp: allocation flags
+ *
+ * Use this function to report to userspace when a beacon was
+ * received. It is not useful to call this when there is no
+ * netdev that is in AP/GO mode.
+ */
+void cfg80211_report_obss_beacon(struct wiphy *wiphy,
+                                 const u8 *frame, size_t len,
+                                 int freq, gfp_t gfp);
+
 /* Logging, debugging and troubleshooting/diagnostic helpers. */
 
 /* wiphy_printk helpers, similar to dev_printk */
diff --git a/net/wireless/core.h b/net/wireless/core.h
index b9ec3061ed72..4c6ff4024356 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -54,6 +54,8 @@ struct cfg80211_registered_device {
         int opencount; /* also protected by devlist_mtx */
         wait_queue_head_t dev_wait;
 
+        u32 ap_beacons_nlpid;
+
         /* BSSes/scanning */
         spinlock_t bss_lock;
         struct list_head bss_list;
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index a8eda12b46a8..68b6708b996f 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -891,6 +891,10 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
         if (dev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SCHED_SCAN)
                 CMD(sched_scan_start, START_SCHED_SCAN);
         CMD(probe_client, PROBE_CLIENT);
+        if (dev->wiphy.flags & WIPHY_FLAG_REPORTS_OBSS) {
+                i++;
+                NLA_PUT_U32(msg, i, NL80211_CMD_REGISTER_BEACONS);
+        }
 
 #undef CMD
 
@@ -5907,6 +5911,21 @@ static int nl80211_probe_client(struct sk_buff *skb,
         return err;
 }
 
+static int nl80211_register_beacons(struct sk_buff *skb, struct genl_info *info)
+{
+        struct cfg80211_registered_device *rdev = info->user_ptr[0];
+
+        if (!(rdev->wiphy.flags & WIPHY_FLAG_REPORTS_OBSS))
+                return -EOPNOTSUPP;
+
+        if (rdev->ap_beacons_nlpid)
+                return -EBUSY;
+
+        rdev->ap_beacons_nlpid = info->snd_pid;
+
+        return 0;
+}
+
 #define NL80211_FLAG_NEED_WIPHY         0x01
 #define NL80211_FLAG_NEED_NETDEV        0x02
 #define NL80211_FLAG_NEED_RTNL          0x04
@@ -6478,6 +6497,14 @@ static struct genl_ops nl80211_ops[] = {
                 .internal_flags = NL80211_FLAG_NEED_NETDEV |
                                   NL80211_FLAG_NEED_RTNL,
         },
+        {
+                .cmd = NL80211_CMD_REGISTER_BEACONS,
+                .doit = nl80211_register_beacons,
+                .policy = nl80211_policy,
+                .flags = GENL_ADMIN_PERM,
+                .internal_flags = NL80211_FLAG_NEED_WIPHY |
+                                  NL80211_FLAG_NEED_RTNL,
+        },
 };
 
 static struct genl_multicast_group nl80211_mlme_mcgrp = {
@@ -7582,6 +7609,44 @@ void cfg80211_probe_status(struct net_device *dev, const u8 *addr,
 }
 EXPORT_SYMBOL(cfg80211_probe_status);
 
+void cfg80211_report_obss_beacon(struct wiphy *wiphy,
+                                 const u8 *frame, size_t len,
+                                 int freq, gfp_t gfp)
+{
+        struct cfg80211_registered_device *rdev = wiphy_to_dev(wiphy);
+        struct sk_buff *msg;
+        void *hdr;
+        u32 nlpid = ACCESS_ONCE(rdev->ap_beacons_nlpid);
+
+        if (!nlpid)
+                return;
+
+        msg = nlmsg_new(len + 100, gfp);
+        if (!msg)
+                return;
+
+        hdr = nl80211hdr_put(msg, 0, 0, 0, NL80211_CMD_FRAME);
+        if (!hdr) {
+                nlmsg_free(msg);
+                return;
+        }
+
+        NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, rdev->wiphy_idx);
+        if (freq)
+                NLA_PUT_U32(msg, NL80211_ATTR_WIPHY_FREQ, freq);
+        NLA_PUT(msg, NL80211_ATTR_FRAME, len, frame);
+
+        genlmsg_end(msg, hdr);
+
+        genlmsg_unicast(wiphy_net(&rdev->wiphy), msg, nlpid);
+        return;
+
+ nla_put_failure:
+        genlmsg_cancel(msg, hdr);
+        nlmsg_free(msg);
+}
+EXPORT_SYMBOL(cfg80211_report_obss_beacon);
+
 static int nl80211_netlink_notify(struct notifier_block * nb,
                                   unsigned long state,
                                   void *_notify)
@@ -7595,9 +7660,12 @@ static int nl80211_netlink_notify(struct notifier_block * nb,
 
         rcu_read_lock();
 
-        list_for_each_entry_rcu(rdev, &cfg80211_rdev_list, list)
+        list_for_each_entry_rcu(rdev, &cfg80211_rdev_list, list) {
                 list_for_each_entry_rcu(wdev, &rdev->netdev_list, list)
                         cfg80211_mlme_unregister_socket(wdev, notify->pid);
+                if (rdev->ap_beacons_nlpid == notify->pid)
+                        rdev->ap_beacons_nlpid = 0;
+        }
 
         rcu_read_unlock();