cfg80211: issue netlink notification when scan starts

To ease multiple apps working together smoothly,
send a notification when a scan is started.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 34 insertions, 10 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index f91e5d472c60..5a6c4ca59398 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2839,6 +2839,9 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
         drv->scan_req = request;
         err = drv->ops->scan(&drv->wiphy, dev, request);
 
+        if (!err)
+                nl80211_send_scan_start(drv, dev);
+
  out_free:
         if (err) {
                 drv->scan_req = NULL;
@@ -3665,11 +3668,11 @@ static int nl80211_add_scan_req(struct sk_buff *msg,
         return -ENOBUFS;
 }
 
-static int nl80211_send_scan_donemsg(struct sk_buff *msg,
-                                     struct cfg80211_registered_device *rdev,
-                                     struct net_device *netdev,
-                                     u32 pid, u32 seq, int flags,
-                                     u32 cmd)
+static int nl80211_send_scan_msg(struct sk_buff *msg,
+                                 struct cfg80211_registered_device *rdev,
+                                 struct net_device *netdev,
+                                 u32 pid, u32 seq, int flags,
+                                 u32 cmd)
 {
         void *hdr;
 
@@ -3690,6 +3693,24 @@ static int nl80211_send_scan_donemsg(struct sk_buff *msg,
         return -EMSGSIZE;
 }
 
+void nl80211_send_scan_start(struct cfg80211_registered_device *rdev,
+                             struct net_device *netdev)
+{
+        struct sk_buff *msg;
+
+        msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+        if (!msg)
+                return;
+
+        if (nl80211_send_scan_msg(msg, rdev, netdev, 0, 0, 0,
+                                  NL80211_CMD_TRIGGER_SCAN) < 0) {
+                nlmsg_free(msg);
+                return;
+        }
+
+        genlmsg_multicast(msg, 0, nl80211_scan_mcgrp.id, GFP_KERNEL);
+}
+
 void nl80211_send_scan_done(struct cfg80211_registered_device *rdev,
                             struct net_device *netdev)
 {
@@ -3699,8 +3720,8 @@ void nl80211_send_scan_done(struct cfg80211_registered_device *rdev,
         if (!msg)
                 return;
 
-        if (nl80211_send_scan_donemsg(msg, rdev, netdev, 0, 0, 0,
-                                      NL80211_CMD_NEW_SCAN_RESULTS) < 0) {
+        if (nl80211_send_scan_msg(msg, rdev, netdev, 0, 0, 0,
+                                  NL80211_CMD_NEW_SCAN_RESULTS) < 0) {
                 nlmsg_free(msg);
                 return;
         }
@@ -3717,8 +3738,8 @@ void nl80211_send_scan_aborted(struct cfg80211_registered_device *rdev,
         if (!msg)
                 return;
 
-        if (nl80211_send_scan_donemsg(msg, rdev, netdev, 0, 0, 0,
-                                      NL80211_CMD_SCAN_ABORTED) < 0) {
+        if (nl80211_send_scan_msg(msg, rdev, netdev, 0, 0, 0,
+                                  NL80211_CMD_SCAN_ABORTED) < 0) {
                 nlmsg_free(msg);
                 return;
         }
diff --git a/net/wireless/nl80211.h b/net/wireless/nl80211.h
index 5c12ad13499b..a3872a40cfa7 100644
--- a/net/wireless/nl80211.h
+++ b/net/wireless/nl80211.h
@@ -6,6 +6,8 @@
 extern int nl80211_init(void);
 extern void nl80211_exit(void);
 extern void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev);
+extern void nl80211_send_scan_start(struct cfg80211_registered_device *rdev,
+                                    struct net_device *netdev);
 extern void nl80211_send_scan_done(struct cfg80211_registered_device *rdev,
                                    struct net_device *netdev);
 extern void nl80211_send_scan_aborted(struct cfg80211_registered_device *rdev,
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index f8e71b300001..261a06386822 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -647,7 +647,8 @@ int cfg80211_wext_siwscan(struct net_device *dev,
         if (err) {
                 rdev->scan_req = NULL;
                 kfree(creq);
-        }
+        } else
+                nl80211_send_scan_start(rdev, dev);
  out:
         cfg80211_put_dev(rdev);
         return err;