python: Add TCP/SSL probes for OVSDB python lib

stream_or_pstream_needs_probes always return 0. This causes TCP/SSL
connection not be probed, and no reconnect when the connection
is aborted

Signed-off-by: Guoshuai Li <ligs@dtdream.com>
Signed-off-by: Ben Pfaff <blp@ovn.org>

python/ovs/stream.py

@@ -39,16 +39,18 @@ vlog = ovs.vlog.Vlog("stream")
 
 
 def stream_or_pstream_needs_probes(name):
-    """ 1 if the stream or pstream specified by 'name' needs periodic probes to
-    verify connectivity.  For [p]streams which need probes, it can take a long
-    time to notice the connection was dropped.  Returns 0 if probes aren't
-    needed, and -1 if 'name' is invalid"""
+    """ True if the stream or pstream specified by 'name' needs periodic probes
+    to verify connectivity.  For [p]streams which need probes, it can take a
+    long time to notice the connection was dropped.  Returns False if probes
+    aren't needed, and None if 'name' is invalid"""
 
-    if PassiveStream.is_valid_name(name) or Stream.is_valid_name(name):
-        # Only unix and punix are supported currently.
-        return 0
+    cls = Stream._find_method(name)
+    if cls:
+        return cls.needs_probes()
+    elif PassiveStream.is_valid_name(name):
+        return PassiveStream.needs_probes(name)
     else:
-        return -1
+        return None
 
 
 class Stream(object):
@@ -524,6 +526,10 @@ class PassiveStream(object):
     connect = None                  # overlapped for read operation
     connect_pending = False
 
+    @staticmethod
+    def needs_probes(name):
+        return False if name.startswith("punix:") else True
+
     @staticmethod
     def is_valid_name(name):
         """Returns True if 'name' is a passive stream name in the form
@@ -708,6 +714,10 @@ Passive %s connection methods:
 
 
 class UnixStream(Stream):
+    @staticmethod
+    def needs_probes():
+        return False
+
     @staticmethod
     def _open(suffix, dscp):
         connect_path = suffix
@@ -719,6 +729,10 @@ Stream.register_method("unix", UnixStream)
 
 
 class TCPStream(Stream):
+    @staticmethod
+    def needs_probes():
+        return True
+
     @staticmethod
     def _open(suffix, dscp):
         error, sock = ovs.socket_util.inet_open_active(socket.SOCK_STREAM,
@@ -732,6 +746,9 @@ Stream.register_method("tcp", TCPStream)
 
 
 class SSLStream(Stream):
+    @staticmethod
+    def needs_probes():
+        return True
 
     @staticmethod
     def verify_cb(conn, cert, errnum, depth, ok):