1 files changed, 147 insertions, 0 deletions
diff --git a/src/killswitch.vala b/src/killswitch.vala
new file mode 100644
index 0000000..92b1a3c
--- /dev/null
+++ b/src/killswitch.vala
@@ -0,0 +1,147 @@
+/*
+ * Copyright 2013 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 3.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *   Charles Kerr <charles.kerr@canonical.com>
+ */
+
+/**
+ * Monitors whether or not bluetooth is blocked,
+ * either by software (e.g., a session configuration setting)
+ * or by hardware (e.g., user disabled it via a physical switch on her laptop)
+ */
+public class KillSwitch: Object
+{
+  public bool blocked { get; protected set; default = false; }
+
+  public void try_set_blocked (bool blocked)
+  {
+    return_if_fail (this.blocked != blocked);
+
+    // write a 'soft kill' event to fkill
+    var event = Linux.RfKillEvent() {
+      op    = Linux.RfKillOp.CHANGE_ALL,
+      type  = Linux.RfKillType.BLUETOOTH,
+      soft  = (uint8)blocked
+    };
+
+    var bwritten = Posix.write (fd, &event, sizeof(Linux.RfKillEvent));
+    if (bwritten == -1)
+      warning ("Could not write rfkill event: %s", strerror(errno));
+  }
+
+  /***
+  ****  Past this point, it's all RfKill implementation details...
+  ***/
+
+  private class Entry
+  {
+    public uint32 idx;
+    public Linux.RfKillType type;
+    public bool soft;
+    public bool hard;
+  }
+
+  private HashTable<uint32,Entry> entries;
+  private int fd;
+  private IOChannel channel;
+  private uint watch;
+
+  private bool calculate_blocked ()
+  {
+    foreach (Entry entry in entries.get_values())
+      if (entry.soft || entry.hard)
+        return true;
+
+    return false;
+  }
+
+  ~KillSwitch ()
+  {
+    Source.remove (watch);
+    Posix.close (fd);
+  }
+
+  public KillSwitch ()
+  {
+    entries = new HashTable<uint32,Entry>(direct_hash, direct_equal);
+
+    var path = "/dev/rfkill";
+    fd = Posix.open (path, Posix.O_RDWR | Posix.O_NONBLOCK );
+    message ("fd is %d", fd);
+    if (fd == -1)
+      {
+        warning (@"Can't open $path: $(strerror(errno)); KillSwitch disable");
+      }
+    else
+      {
+        // read everything that's already there, then watch for more
+        while (read_event());
+        channel = new IOChannel.unix_new (fd);
+        watch = channel.add_watch (IOCondition.IN, on_channel_event);
+      }
+  }
+
+  private bool on_channel_event (IOChannel source, IOCondition condition)
+  {
+    read_event ();
+    return true;
+  }
+
+  private bool read_event ()
+  {
+    assert (fd != -1);
+
+    var event = Linux.RfKillEvent();
+    var n = sizeof (Linux.RfKillEvent);
+    var bytesread = Posix.read (fd, &event, n);
+   
+    if (bytesread == n)
+      {
+        process_event (event);
+        return true;
+      }
+
+    return false;
+  }
+
+  private void process_event (Linux.RfKillEvent event)
+  {
+    // we only want things that affect bluetooth
+    if ((event.type != Linux.RfKillType.ALL) &&
+        (event.type != Linux.RfKillType.BLUETOOTH))
+      return;
+
+    switch (event.op)
+      {
+        case Linux.RfKillOp.CHANGE:
+        case Linux.RfKillOp.ADD:
+          Entry entry = new Entry ();
+          entry.idx = event.idx;
+          entry.type = event.type;
+          entry.soft = event.soft != 0;
+          entry.hard = event.hard != 0;
+          entries.insert (entry.idx, entry);
+          break;
+
+        case Linux.RfKillOp.DEL:
+          entries.remove (event.idx);
+          break;
+      }
+
+    // update the 'blocked' property
+    blocked = calculate_blocked ();
+  }
+}