BNetworkDevice: Implement Scan().

This depends on the previous commit to return the correct error code
from ioctl().

If there are no VAPs running (which is the case after a forced disconnect
from an access point), scans will fail. In that case, we call
IEEE80211_IOC_HAIKU_COMPAT_WLAN_UP, which will restart a VAP, and then
initiate the scan.

Change-Id: I732aefe67e386dbb0ed3d232ed9deda678132601
Reviewed-on: https://review.haiku-os.org/551
Reviewed-by: waddlesplash <[email protected]>

src/kits/network/libnetapi/NetworkDevice.cpp

@@ -13,9 +13,11 @@
 #include <sys/sockio.h>
 
 #include <Messenger.h>
+#include <Looper.h>
 
 #include <AutoDeleter.h>
 #include <NetServer.h>
+#include <NetworkNotifications.h>
 
 extern "C" {
 #	include <compat/sys/cdefs.h>
@@ -42,6 +44,9 @@ struct ie_data {
 };
 
 
+// #pragma mark - private functions (code shared with net_server)
+
+
 static status_t
 get_80211(const char* name, int32 type, void* data, int32& length)
 {
@@ -66,6 +71,30 @@ get_80211(const char* name, int32 type, void* data, int32& length)
 }
 
 
+static status_t
+set_80211(const char* name, int32 type, void* data,
+	int32 length = 0, int32 value = 0)
+{
+	int socket = ::socket(AF_INET, SOCK_DGRAM, 0);
+	if (socket < 0)
+		return errno;
+
+	FileDescriptorCloser closer(socket);
+
+	struct ieee80211req ireq;
+	strlcpy(ireq.i_name, name, IF_NAMESIZE);
+	ireq.i_type = type;
+	ireq.i_val = value;
+	ireq.i_len = length;
+	ireq.i_data = data;
+
+	if (ioctl(socket, SIOCS80211, &ireq, sizeof(struct ieee80211req)) < 0)
+		return errno;
+
+	return B_OK;
+}
+
+
 template<typename T> status_t
 do_request(T& request, const char* name, int option)
 {
@@ -687,17 +716,87 @@ BNetworkDevice::Control(int option, void* request)
 status_t
 BNetworkDevice::Scan(bool wait, bool forceRescan)
 {
-#if 0
-	if (index == 0) {
-		struct ieee80211_scan_req request;
-		memset(&request, 0, sizeof(request));
-		request.sr_flags = IEEE80211_IOC_SCAN_ACTIVE | IEEE80211_IOC_SCAN_ONCE
-			| IEEE80211_IOC_SCAN_NOJOIN;
-		request.sr_duration = IEEE80211_IOC_SCAN_FOREVER;
-		set_80211(Name(), IEEE80211_IOC_SCAN_REQ, NULL);
+	// Network status listener for change notifications
+	class ScanListener : public BLooper {
+	public:
+		ScanListener(BString iface)
+			:
+			fInterface(iface)
+		{
+			start_watching_network(B_WATCH_NETWORK_WLAN_CHANGES, this);
+		}
+		virtual ~ScanListener()
+		{
+			stop_watching_network(this);
+		}
+
+	protected:
+		virtual void MessageReceived(BMessage *message)
+		{
+			if (message->what != B_NETWORK_MONITOR) {
+				BLooper::MessageReceived(message);
+				return;
+			}
+
+			BString interfaceName;
+			if (message->FindString("interface", &interfaceName) != B_OK)
+				return;
+			if (fInterface.FindFirst(interfaceName) < 0)
+				return;
+			if (message->FindInt32("opcode") != B_NETWORK_WLAN_SCANNED)
+				return;
+
+			Lock();
+			Quit();
+		}
+
+	private:
+		BString fInterface;
+	};
+
+	ScanListener* listener = NULL;
+	if (wait)
+		listener = new ScanListener(Name());
+
+	// Trigger the scan
+	struct ieee80211_scan_req request;
+	memset(&request, 0, sizeof(request));
+	request.sr_flags = IEEE80211_IOC_SCAN_ACTIVE
+		| IEEE80211_IOC_SCAN_BGSCAN
+		| IEEE80211_IOC_SCAN_NOPICK
+		| IEEE80211_IOC_SCAN_ONCE
+		| (forceRescan ? IEEE80211_IOC_SCAN_FLUSH : 0);
+	request.sr_duration = IEEE80211_IOC_SCAN_FOREVER;
+	request.sr_nssid = 0;
+
+	status_t status = set_80211(Name(), IEEE80211_IOC_SCAN_REQ, &request,
+		sizeof(request));
+
+	// If there are no VAPs running, the net80211 layer will return ENXIO.
+	// Try to bring up the interface (which should start a VAP) and try again.
+	if (status == ENXIO) {
+		struct ieee80211req dummy;
+		status = set_80211(Name(), IEEE80211_IOC_HAIKU_COMPAT_WLAN_UP, &dummy,
+			sizeof(dummy));
+		if (status != B_OK)
+			return status;
+
+		status = set_80211(Name(), IEEE80211_IOC_SCAN_REQ, &request,
+			sizeof(request));
 	}
-#endif
-	return B_ERROR;
+
+	// If there is already a scan currently running, it's probably an "infinite"
+	// one, which we of course don't want to wait for. So just return immediately
+	// if that's the case.
+	if (status == EINPROGRESS)
+		return B_OK;
+
+	if (!wait || status != B_OK)
+		return status;
+
+	while (wait_for_thread(listener->Run(), NULL) == B_INTERRUPTED)
+		;
+	return B_OK;
 }