socket-util: Avoid using SO_ERROR.

[openvswitch] / python / ovs / socket_util.py

diff --git a/python/ovs/socket_util.py b/python/ovs/socket_util.py
index 4f4f603624b094bfd465131613c87c5098c3f706..e6b6fcef9c2a486cffd240d9af04427f6cfbb693 100644 (file)
--- a/python/ovs/socket_util.py
+++ b/python/ovs/socket_util.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2010 Nicira Networks
+# Copyright (c) 2010, 2012 Nicira, Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,13 +13,17 @@
 # limitations under the License.
 
 import errno
-import logging
 import os
 import select
 import socket
 import sys
 
 import ovs.fatal_signal
+import ovs.poller
+import ovs.vlog
+
+vlog = ovs.vlog.Vlog("socket_util")
+
 
 def make_unix_socket(style, nonblock, bind_path, connect_path):
     """Creates a Unix domain socket in the given 'style' (either
@@ -66,27 +70,75 @@ def make_unix_socket(style, nonblock, bind_path, connect_path):
         return 0, sock
     except socket.error, e:
         sock.close()
-        try:
-            os.unlink(bind_path)
-        except OSError, e:
-            pass
         if bind_path is not None:
-            ovs.fatal_signal.add_file_to_unlink(bind_path)
+            ovs.fatal_signal.unlink_file_now(bind_path)
         return get_exception_errno(e), None
 
+
 def check_connection_completion(sock):
-    p = select.poll()
-    p.register(sock, select.POLLOUT)
-    if len(p.poll(0)) == 1:
-        return get_socket_error(sock)
+    p = ovs.poller.SelectPoll()
+    p.register(sock, ovs.poller.POLLOUT)
+    pfds = p.poll(0)
+    if len(pfds) == 1:
+        revents = pfds[0][1]
+        if revents & ovs.poller.POLLERR:
+            try:
+                # The following should raise an exception.
+                socket.send("\0", socket.MSG_DONTWAIT)
+
+                # (Here's where we end up if it didn't.)
+                # XXX rate-limit
+                vlog.err("poll return POLLERR but send succeeded")
+                return errno.EPROTO
+            except socket.error, e:
+                return get_exception_errno(e)
+        else:
+            return 0
     else:
         return errno.EAGAIN
 
+
+def inet_parse_active(target, default_port):
+    address = target.split(":")
+    host_name = address[0]
+    if not host_name:
+        raise ValueError("%s: bad peer name format" % target)
+    if len(address) >= 2:
+        port = int(address[1])
+    elif default_port:
+        port = default_port
+    else:
+        raise ValueError("%s: port number must be specified" % target)
+    return (host_name, port)
+
+
+def inet_open_active(style, target, default_port, dscp):
+    address = inet_parse_active(target, default_port)
+    try:
+        sock = socket.socket(socket.AF_INET, style, 0)
+    except socket.error, e:
+        return get_exception_errno(e), None
+
+    try:
+        set_nonblocking(sock)
+        set_dscp(sock, dscp)
+        try:
+            sock.connect(address)
+        except socket.error, e:
+            if get_exception_errno(e) != errno.EINPROGRESS:
+                raise
+        return 0, sock
+    except socket.error, e:
+        sock.close()
+        return get_exception_errno(e), None
+
+
 def get_socket_error(sock):
     """Returns the errno value associated with 'socket' (0 if no error) and
     resets the socket's error status."""
     return sock.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
 
+
 def get_exception_errno(e):
     """A lot of methods on Python socket objects raise socket.error, but that
     exception is documented as having two completely different forms of
@@ -97,7 +149,10 @@ def get_exception_errno(e):
     else:
         return errno.EPROTO
 
+
 null_fd = -1
+
+
 def get_null_fd():
     """Returns a readable and writable fd for /dev/null, if successful,
     otherwise a negative errno value.  The caller must not close the returned
@@ -107,11 +162,11 @@ def get_null_fd():
         try:
             null_fd = os.open("/dev/null", os.O_RDWR)
         except OSError, e:
-            logging.error("could not open /dev/null: %s"
-                          % os.strerror(e.errno))
+            vlog.err("could not open /dev/null: %s" % os.strerror(e.errno))
             return -e.errno
     return null_fd
 
+
 def write_fully(fd, buf):
     """Returns an (error, bytes_written) tuple where 'error' is 0 on success,
     otherwise a positive errno value, and 'bytes_written' is the number of
@@ -127,7 +182,7 @@ def write_fully(fd, buf):
             if retval == len(buf):
                 return 0, bytes_written + len(buf)
             elif retval == 0:
-                logging.warning("write returned 0")
+                vlog.warn("write returned 0")
                 return errno.EPROTO, bytes_written
             else:
                 bytes_written += retval
@@ -135,9 +190,17 @@ def write_fully(fd, buf):
         except OSError, e:
             return e.errno, bytes_written
 
+
 def set_nonblocking(sock):
     try:
         sock.setblocking(0)
     except socket.error, e:
-        logging.error("could not set nonblocking mode on socket: %s"
-                      % os.strerror(get_socket_error(e)))
+        vlog.err("could not set nonblocking mode on socket: %s"
+                 % os.strerror(get_exception_errno(e)))
+
+
+def set_dscp(sock, dscp):
+    if dscp > 63:
+        raise ValueError("Invalid dscp %d" % dscp)
+    val = dscp << 2
+    sock.setsockopt(socket.IPPROTO_IP, socket.IP_TOS, val)