xend: Implement DGRAM (connectionless) type socket listeners

Introduce SocketDgramListener and UnixDgramListener classes.
We already have STREAM (connection) type socket listener classes in
the source tree, but we need DGRAM (connectionless) type listeners to
receive udev events.

Signed-off-by: Yosuke Iwamatsu <y-iwamatsu@ab.jp.nec.com>

diff --git a/tools/python/xen/web/connection.py b/tools/python/xen/web/connection.py
index 7d5702fce066489dc8b62c021186aa2a81fdf114..e507323e9155ebbe4b279470d4dd72867ad1e420 100644 (file)
--- a/tools/python/xen/web/connection.py
+++ b/tools/python/xen/web/connection.py
@@ -292,3 +292,40 @@ def hostAllowed(addrport, hosts_allowed):
                 return True
         log.warn("Rejected connection from %s (%s).", addrport[0], fqdn)
         return False
+
+
+class SocketDgramListener:
+    """A connectionless server socket, running listen in a thread.
+    """
+
+    def __init__(self, protocol_class):
+        self.protocol = protocol_class()
+        self.sock = self.createSocket()
+        threading.Thread(target=self.main).start()
+
+
+    def close(self):
+        try:
+            self.sock.close()
+        except:
+            pass
+
+
+    def createSocket(self):
+        raise NotImplementedError()
+
+
+    def main(self):
+        try:
+            while True:
+                try:
+                    data = self.sock.recv(BUFFER_SIZE)
+                    self.protocol.dataReceived(data)
+                except socket.error, ex:
+                    if ex.args[0] not in (EWOULDBLOCK, EAGAIN, EINTR):
+                        break
+        finally:
+            try:
+                self.close()
+            except:
+                pass

diff --git a/tools/python/xen/web/unix.py b/tools/python/xen/web/unix.py
index 12b6e9694edb69401b25cf12222d392648a12526..180c0858ebd0c91c3b5957fbe411d573976f8f42 100644 (file)
--- a/tools/python/xen/web/unix.py
+++ b/tools/python/xen/web/unix.py
@@ -27,16 +27,19 @@ from xen.util import mkdir
 import connection
 
 
-def bind(path):
-    """Create a Unix socket, and bind it to the given path.  The socket is
-created such that only the current user may access it."""
+def bind(path, type = socket.SOCK_STREAM):
+    """Create a Unix socket, and bind it to the given path.
+    The socket is created such that only the current user may access it."""
 
-    parent = os.path.dirname(path)
-    mkdir.parents(parent, stat.S_IRWXU, True)
-    if os.path.exists(path):
-        os.unlink(path)
+    if path[0] == '\0': # Abstract namespace is used for the path
+        pass
+    else:
+        parent = os.path.dirname(path)
+        mkdir.parents(parent, stat.S_IRWXU, True)
+        if os.path.exists(path):
+            os.unlink(path)
 
-    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+    sock = socket.socket(socket.AF_UNIX, type)
     sock.bind(path)
     return sock
 
@@ -48,8 +51,19 @@ class UnixListener(connection.SocketListener):
 
 
     def createSocket(self):
-        return bind(self.path)
+        return bind(self.path, socket.SOCK_STREAM)
 
 
     def acceptConnection(self, sock, _):
         connection.SocketServerConnection(sock, self.protocol_class)
+
+
+class UnixDgramListener(connection.SocketDgramListener):
+    def __init__(self, path, protocol_class):
+        self.path = path
+        connection.SocketDgramListener.__init__(self, protocol_class)
+
+
+    def createSocket(self):
+        return bind(self.path, socket.SOCK_DGRAM)
+