Remove protocol names, instead use an enum with common protocols

The whole protocol name thing is pretty weird. The getprotobyname functions
seem to only specify one mapping for name <-> ids, so all families/types
must use the same values. Plus the values used for the protocols are
standardized by IANA, so are always the same.

So, we drop using names for protocols, intead introducing an enum with
a few commonly availible and used protocols.

16 files changed, 417 insertions, 172 deletions

diff --git a/docs/reference/gio/#gio-unused.txt# b/docs/reference/gio/#gio-unused.txt#
new file mode 100644
index 000000000..bf3faa5a1
--- /dev/null
+++ b/docs/reference/gio/#gio-unused.txt#
@@ -0,0 +1,100 @@
+GFenDirectoryMonitor
+GFenDirectoryMonitorClass
+GFenFileMonitor
+GFenFileMonitorClass
+GLocalFileIOStream
+GLocalFileIOStreamClass
+GLocalFileIOStreamPrivate
+GSocketInputStream
+GSocketInputStreamClass
+GSocketInputStreamPrivate
+GSocketOutputStream
+GSocketOutputStreamClass
+GSocketOutputStreamPrivate
+GWin32DirectoryMonitor
+GWin32DirectoryMonitorClass
+GWin32DirectoryMonitorPrivate
+GWin32Mount
+GWin32MountClass
+GWin32Volume
+GWin32VolumeMonitor
+GWin32VolumeMonitorClass
+GWinHttpDllFuncs
+GWinHttpFile
+GWinHttpFileClass
+GWinHttpFileInputStream
+GWinHttpFileInputStreamClass
+GWinHttpFileOutputStream
+GWinHttpFileOutputStreamClass
+GWinHttpVfs
+GWinHttpVfsClass
+G_FEN_DIRECTORY_MONITOR
+G_FEN_DIRECTORY_MONITOR_CLASS
+G_FEN_FILE_MONITOR
+G_FEN_FILE_MONITOR_CLASS
+G_FILE_ATTRIBUTE_STANDARD_ALLOCATED_SIZE
+G_IS_FEN_DIRECTORY_MONITOR
+G_IS_FEN_DIRECTORY_MONITOR_CLASS
+G_IS_FEN_FILE_MONITOR
+G_IS_FEN_FILE_MONITOR_CLASS
+G_IS_LOCAL_FILE_IO_STREAM
+G_IS_LOCAL_FILE_IO_STREAM_CLASS
+G_IS_SOCKET_INPUT_STREAM
+G_IS_SOCKET_INPUT_STREAM_CLASS
+G_IS_SOCKET_OUTPUT_STREAM
+G_IS_SOCKET_OUTPUT_STREAM_CLASS
+G_IS_WIN32_DIRECTORY_MONITOR
+G_IS_WIN32_DIRECTORY_MONITOR_CLASS
+G_IS_WIN32_MOUNT
+G_IS_WIN32_MOUNT_CLASS
+G_IS_WIN32_VOLUME_MONITOR
+G_IS_WIN32_VOLUME_MONITOR_CLASS
+G_IS_WINHTTP_FILE
+G_IS_WINHTTP_FILE_CLASS
+G_IS_WINHTTP_FILE_INPUT_STREAM
+G_IS_WINHTTP_FILE_INPUT_STREAM_CLASS
+G_IS_WINHTTP_FILE_OUTPUT_STREAM
+G_IS_WINHTTP_FILE_OUTPUT_STREAM_CLASS
+G_IS_WINHTTP_VFS
+G_IS_WINHTTP_VFS_CLASS
+G_LOCAL_FILE_IO_STREAM
+G_LOCAL_FILE_IO_STREAM_CLASS
+G_LOCAL_FILE_IO_STREAM_GET_CLASS
+G_SOCKET_INPUT_STREAM
+G_SOCKET_INPUT_STREAM_CLASS
+G_SOCKET_INPUT_STREAM_GET_CLASS
+G_SOCKET_OUTPUT_STREAM
+G_SOCKET_OUTPUT_STREAM_CLASS
+G_SOCKET_OUTPUT_STREAM_GET_CLASS
+G_TYPE_FEN_DIRECTORY_MONITOR
+G_TYPE_FEN_FILE_MONITOR
+G_TYPE_LOCAL_FILE_IO_STREAM
+G_TYPE_SOCKET_OUTPUT_STREAM
+G_TYPE_WIN32_DIRECTORY_MONITOR
+G_TYPE_WIN32_MOUNT
+G_TYPE_WIN32_VOLUME_MONITOR
+G_TYPE_WINHTTP_FILE
+G_TYPE_WINHTTP_FILE_INPUT_STREAM
+G_TYPE_WINHTTP_FILE_OUTPUT_STREAM
+G_TYPE_WINHTTP_VFS
+G_WIN32_DIRECTORY_MONITOR
+G_WIN32_DIRECTORY_MONITOR_CLASS
+G_WIN32_DIRECTORY_MONITOR_GET_CLASS
+G_WIN32_MOUNT
+G_WIN32_MOUNT_CLASS
+G_WIN32_VOLUME_MONITOR
+G_WIN32_VOLUME_MONITOR_CLASS
+G_WINHTTP_FILE
+G_WINHTTP_FILE_CLASS
+G_WINHTTP_FILE_GET_CLASS
+G_WINHTTP_FILE_INPUT_STREAM
+G_WINHTTP_FILE_INPUT_STREAM_CLASS
+G_WINHTTP_FILE_INPUT_STREAM_GET_CLASS
+G_WINHTTP_FILE_OUTPUT_STREAM
+G_WINHTTP_FILE_OUTPUT_STREAM_CLASS
+G_WINHTTP_FILE_OUTPUT_STREAM_GET_CLASS
+G_WINHTTP_VFS
+G_WINHTTP_VFS_CLASS
+G_WINHTTP_VFS_GET_CLASS
+g_win32_directory_monitor_get_type
+g_win32_directory_monitor_register
diff --git a/docs/reference/gio/aa b/docs/reference/gio/aa
new file mode 100644
index 000000000..13ab1c020
--- /dev/null
+++ b/docs/reference/gio/aa
@@ -0,0 +1,74 @@
+               
+<book lang=
+<!ENTITY version SYSTEM 
+xml/extensionpoints.xml
+xml/gappinfo.xml
+xml/gasyncinitable.xml
+xml/gasyncresult.xml
+xml/gbufferedinputstream.xml
+xml/gbufferedoutputstream.xml
+xml/gcancellable.xml
+xml/gcontenttype.xml
+xml/gdatainputstream.xml
+xml/gdataoutputstream.xml
+xml/gdesktopappinfo.xml
+xml/gdrive.xml
+xml/gemblemedicon.xml
+xml/gemblem.xml
+xml/gfileattribute.xml
+xml/gfileenumerator.xml
+xml/gfileicon.xml
+xml/gfileinfo.xml
+xml/gfileinputstream.xml
+xml/gfileiostream.xml
+xml/gfilemonitor.xml
+xml/gfilenamecompleter.xml
+xml/gfileoutputstream.xml
+xml/gfile.xml
+xml/gfilterinputstream.xml
+xml/gfilteroutputstream.xml
+xml/gicon.xml
+xml/ginetaddress.xml
+xml/ginetsocketaddress.xml
+xml/ginitable.xml
+xml/ginputstream.xml
+xml/gioerror.xml
+xml/giomodule.xml
+xml/gioscheduler.xml
+xml/giostream.xml
+xml/gloadableicon.xml
+xml/gmemoryinputstream.xml
+xml/gmemoryoutputstream.xml
+xml/gmountoperation.xml
+xml/gmount.xml
+xml/gnetworkaddress.xml
+xml/gnetworkservice.xml
+xml/goutputstream.xml
+xml/gresolver.xml
+xml/gseekable.xml
+xml/gsimpleasyncresult.xml
+xml/gsocketaddress.xml
+xml/gsocketclient.xml
+xml/gsocketconnectable.xml
+xml/gsocketconnection.xml
+xml/gsocketcontrolmessage.xml
+xml/gsocketlistener.xml
+xml/gsocketservice.xml
+xml/gsocket.xml
+xml/gsrvtarget.xml
+xml/gtcpconnection.xml
+xml/gthemedicon.xml
+xml/gthreadedsocketservice.xml
+xml/gunixconnection.xml
+xml/gunixfdmessage.xml
+xml/gunixinputstream.xml
+xml/gunixmounts.xml
+xml/gunixoutputstream.xml
+xml/gunixsocketaddress.xml
+xml/gvfs.xml
+xml/gvolumemonitor.xml
+xml/gvolume.xml
+xml/migrating.xml
+xml/overview.xml
+xml/tree_index.sgml
+<?xml version=
diff --git a/docs/reference/gio/b b/docs/reference/gio/b
new file mode 100644
index 000000000..4bf6ec2b5
--- /dev/null
+++ b/docs/reference/gio/b
@@ -0,0 +1,77 @@
+xml/api-index-2.18.xml
+xml/api-index-2.18..xml
+xml/api-index-2,20.xml
+xml/api-index-2.20.xml
+xml/api-index-2.22.xml
+xml/api-index-2.22..xml
+xml/api-index-deprecated.xml
+xml/api-index-full.xml
+xml/extensionpoints.xml
+xml/gappinfo.xml
+xml/gasyncinitable.xml
+xml/gasyncresult.xml
+xml/gbufferedinputstream.xml
+xml/gbufferedoutputstream.xml
+xml/gcancellable.xml
+xml/gcontenttype.xml
+xml/gdatainputstream.xml
+xml/gdataoutputstream.xml
+xml/gdesktopappinfo.xml
+xml/gdrive.xml
+xml/gemblemedicon.xml
+xml/gemblem.xml
+xml/gfileattribute.xml
+xml/gfileenumerator.xml
+xml/gfileicon.xml
+xml/gfileinfo.xml
+xml/gfileinputstream.xml
+xml/gfileiostream.xml
+xml/gfilemonitor.xml
+xml/gfilenamecompleter.xml
+xml/gfileoutputstream.xml
+xml/gfile.xml
+xml/gfilterinputstream.xml
+xml/gfilteroutputstream.xml
+xml/gicon.xml
+xml/ginetaddress.xml
+xml/ginetsocketaddress.xml
+xml/ginitable.xml
+xml/ginputstream.xml
+xml/gioerror.xml
+xml/giomodule.xml
+xml/gioscheduler.xml
+xml/giostream.xml
+xml/gloadableicon.xml
+xml/gmemoryinputstream.xml
+xml/gmemoryoutputstream.xml
+xml/gmountoperation.xml
+xml/gmount.xml
+xml/gnetworkaddress.xml
+xml/gnetworkservice.xml
+xml/goutputstream.xml
+xml/gresolver.xml
+xml/gseekable.xml
+xml/gsimpleasyncresult.xml
+xml/gsocketaddress.xml
+xml/gsocketclient.xml
+xml/gsocketconnectable.xml
+xml/gsocketconnection.xml
+xml/gsocketcontrolmessage.xml
+xml/gsocketlistener.xml
+xml/gsocketservice.xml
+xml/gsocket.xml
+xml/gsrvtarget.xml
+xml/gtcpconnection.xml
+xml/gthemedicon.xml
+xml/gthreadedsocketservice.xml
+xml/gunixconnection.xml
+xml/gunixfdmessage.xml
+xml/gunixinputstream.xml
+xml/gunixmounts.xml
+xml/gunixoutputstream.xml
+xml/gunixsocketaddress.xml
+xml/gvfs.xml
+xml/gvolumemonitor.xml
+xml/gvolume.xml
+xml/migrating.xml
+xml/overview.xml
diff --git a/docs/reference/gio/bb b/docs/reference/gio/bb
new file mode 100644
index 000000000..4bf6ec2b5
--- /dev/null
+++ b/docs/reference/gio/bb
@@ -0,0 +1,77 @@
+xml/api-index-2.18.xml
+xml/api-index-2.18..xml
+xml/api-index-2,20.xml
+xml/api-index-2.20.xml
+xml/api-index-2.22.xml
+xml/api-index-2.22..xml
+xml/api-index-deprecated.xml
+xml/api-index-full.xml
+xml/extensionpoints.xml
+xml/gappinfo.xml
+xml/gasyncinitable.xml
+xml/gasyncresult.xml
+xml/gbufferedinputstream.xml
+xml/gbufferedoutputstream.xml
+xml/gcancellable.xml
+xml/gcontenttype.xml
+xml/gdatainputstream.xml
+xml/gdataoutputstream.xml
+xml/gdesktopappinfo.xml
+xml/gdrive.xml
+xml/gemblemedicon.xml
+xml/gemblem.xml
+xml/gfileattribute.xml
+xml/gfileenumerator.xml
+xml/gfileicon.xml
+xml/gfileinfo.xml
+xml/gfileinputstream.xml
+xml/gfileiostream.xml
+xml/gfilemonitor.xml
+xml/gfilenamecompleter.xml
+xml/gfileoutputstream.xml
+xml/gfile.xml
+xml/gfilterinputstream.xml
+xml/gfilteroutputstream.xml
+xml/gicon.xml
+xml/ginetaddress.xml
+xml/ginetsocketaddress.xml
+xml/ginitable.xml
+xml/ginputstream.xml
+xml/gioerror.xml
+xml/giomodule.xml
+xml/gioscheduler.xml
+xml/giostream.xml
+xml/gloadableicon.xml
+xml/gmemoryinputstream.xml
+xml/gmemoryoutputstream.xml
+xml/gmountoperation.xml
+xml/gmount.xml
+xml/gnetworkaddress.xml
+xml/gnetworkservice.xml
+xml/goutputstream.xml
+xml/gresolver.xml
+xml/gseekable.xml
+xml/gsimpleasyncresult.xml
+xml/gsocketaddress.xml
+xml/gsocketclient.xml
+xml/gsocketconnectable.xml
+xml/gsocketconnection.xml
+xml/gsocketcontrolmessage.xml
+xml/gsocketlistener.xml
+xml/gsocketservice.xml
+xml/gsocket.xml
+xml/gsrvtarget.xml
+xml/gtcpconnection.xml
+xml/gthemedicon.xml
+xml/gthreadedsocketservice.xml
+xml/gunixconnection.xml
+xml/gunixfdmessage.xml
+xml/gunixinputstream.xml
+xml/gunixmounts.xml
+xml/gunixoutputstream.xml
+xml/gunixsocketaddress.xml
+xml/gvfs.xml
+xml/gvolumemonitor.xml
+xml/gvolume.xml
+xml/migrating.xml
+xml/overview.xml
diff --git a/docs/reference/gio/gio-sections.txt b/docs/reference/gio/gio-sections.txt
index e2fce8fbf..d882c01a7 100644
--- a/docs/reference/gio/gio-sections.txt
+++ b/docs/reference/gio/gio-sections.txt
@@ -1631,6 +1631,7 @@ g_network_service_get_type
 GSocket
 GSocketSourceFunc
 GSocketType
+GSocketProtocol
 GSocketMsgFlags
 GInputVector
 GOutputVector
@@ -1663,11 +1664,9 @@ g_socket_set_keepalive
 g_socket_get_family
 g_socket_get_fd
 g_socket_get_local_address
-g_socket_get_protocol_id
-g_socket_get_protocol_name
+g_socket_get_protocol
 g_socket_get_remote_address
 g_socket_get_socket_type
-g_socket_protocol_id_lookup_by_name
 <SUBSECTION Standard>
 GSocketClass
 G_IS_SOCKET
diff --git a/gio/gio.symbols b/gio/gio.symbols
index 7db9b5c25..70ba75000 100644
--- a/gio/gio.symbols
+++ b/gio/gio.symbols
@@ -1078,9 +1078,7 @@ g_socket_get_fd
 g_socket_get_keepalive
 g_socket_get_listen_backlog
 g_socket_get_local_address
-g_socket_get_protocol_id
-g_socket_get_protocol_name
-g_socket_protocol_id_lookup_by_name
+g_socket_get_protocol
 g_socket_get_remote_address
 g_socket_get_socket_type
 g_socket_is_closed
diff --git a/gio/gioenums.h b/gio/gioenums.h
index 2f5ad760a..6b6ef4027 100644
--- a/gio/gioenums.h
+++ b/gio/gioenums.h
@@ -556,6 +556,30 @@ typedef enum
   G_SOCKET_MSG_DONTROUTE = GLIB_SYSDEF_MSG_DONTROUTE
 } GSocketMsgFlags;
 
+/**
+ * GSocketProtocol:
+ * @G_SOCKET_PROTOCOL_UNKNOWN: The protocol type is unknown
+ * @G_SOCKET_PROTOCOL_DEFAULT: The default protocol for the family/type
+ * @G_SOCKET_PROTOCOL_TCP: Tcp over IP
+ * @G_SOCKET_PROTOCOL_UDP: UDP over IP
+ * @G_SOCKET_PROTOCOL_SCTP: SCTP over IP
+ *
+ * A protocol identifier is specified when creating a #GSocket, which is a family/type
+ * specific identifier, where 0 means the default protocol for the particular family/type.
+ * This enum contains a set of commonly availible and used protocols. You can also
+ * pass any other identifiers handled by the platform in order to use protocols not
+ * listed here.
+ *
+ * Since: 2.22
+ */
+typedef enum {
+  G_SOCKET_PROTOCOL_UNKNOWN = -1,
+  G_SOCKET_PROTOCOL_DEFAULT = 0,
+  G_SOCKET_PROTOCOL_TCP     = 6,
+  G_SOCKET_PROTOCOL_UDP     = 17,
+  G_SOCKET_PROTOCOL_SCTP    = 132
+} GSocketProtocol;
+
 G_END_DECLS
 
 #endif /* __GIO_ENUMS_H__ */
diff --git a/gio/gsocket.c b/gio/gsocket.c
index e5e6fe810..4d33394ba 100644
--- a/gio/gsocket.c
+++ b/gio/gsocket.c
@@ -132,7 +132,7 @@ struct _GSocketPrivate
 {
   GSocketFamily   family;
   GSocketType     type;
-  gint            protocol;
+  GSocketProtocol protocol;
   gint            fd;
   gint            listen_backlog;
   GError         *construct_error;
@@ -400,88 +400,10 @@ g_socket_details_from_fd (GSocket *socket)
 	       socket_strerror (errsv));
 }
 
-static char *
-get_protocol_name (int protocol_id)
-{
-  struct protoent *protoent;
-#ifdef HAVE_GETPROTOBYNUMBER_R
-  char buffer[1024];
-  struct protoent my_protoent;
-#endif
-
-  if (protocol_id == 0)
-    return NULL;
-
-  if (protocol_id == -1)
-    return g_strdup ("unknown");
-
-#ifdef HAVE_GETPROTOBYNUMBER_R
-  protoent = NULL;
-  getprotobynumber_r (protocol_id,
-		      &my_protoent, buffer, sizeof (buffer),
-		      &protoent);
-#else
-  protoent = getprotobynumber (protocol_id);
-#endif
-
-  if (protoent == NULL)
-    return g_strdup_printf ("proto-%d", protocol_id);
-
-  return g_strdup (protoent->p_name);
-}
-
-/**
- * g_socket_protocol_id_lookup_by_name:
- * @protocol_name: The name of a protocol, or %NULL
- *
- * Tries to look up the protocol id for a given
- * protocol name. If the protocol name is not known
- * on this system it returns -1.
- *
- * If @protocol_name is %NULL (default protocol) then
- * 0 is returned.
- *
- * Returns: a protocol id, or -1 if unknown
- *
- * Since: 2.22
- **/
-gint
-g_socket_protocol_id_lookup_by_name (const char *protocol_name)
-{
-  struct protoent *protoent;
-  int protocol = 0;
-#ifdef HAVE_GETPROTOBYNAME_R
-  char buffer[1024];
-  struct protoent my_protoent;
-#endif
-
-  if (!protocol_name)
-    return 0;
-
-#ifdef HAVE_GETPROTOBYNAME_R
-  protoent = NULL;
-  getprotobyname_r (protocol_name,
-		    &my_protoent, buffer, sizeof (buffer),
-		    &protoent);
-#else
-  protoent = getprotobyname (protocol_name);
-#endif
-
-  if (protoent == NULL)
-    {
-      if (g_str_has_prefix (protocol_name, "proto-"))
-	return atoi (protocol_name + strlen ("proto-"));
-      return -1;
-    }
-  protocol = protoent->p_proto;
-
-  return protocol;
-}
-
 static gint
 g_socket_create_socket (GSocketFamily   family,
 			GSocketType     type,
-			int             protocol_id,
+			int             protocol,
 			GError        **error)
 {
   gint native_type;
@@ -505,7 +427,7 @@ g_socket_create_socket (GSocketFamily   family,
       g_assert_not_reached ();
     }
 
-  if (protocol_id == -1)
+  if (protocol == -1)
     {
       g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
 		   _("Unable to create socket: %s"), _("Unknown protocol was specified"));
@@ -515,7 +437,7 @@ g_socket_create_socket (GSocketFamily   family,
 #ifdef SOCK_CLOEXEC
   native_type |= SOCK_CLOEXEC;
 #endif
-  fd = socket (family, native_type, protocol_id);
+  fd = socket (family, native_type, protocol);
 
   if (fd < 0)
     {
@@ -589,7 +511,7 @@ g_socket_get_property (GObject    *object,
 	break;
 
       case PROP_PROTOCOL:
-	g_value_set_int (value, socket->priv->protocol);
+	g_value_set_enum (value, socket->priv->protocol);
 	break;
 
       case PROP_FD:
@@ -642,7 +564,7 @@ g_socket_set_property (GObject      *object,
 	break;
 
       case PROP_PROTOCOL:
-	socket->priv->protocol = g_value_get_int (value);
+	socket->priv->protocol = g_value_get_enum (value);
 	break;
 
       case PROP_FD:
@@ -718,12 +640,11 @@ g_socket_class_init (GSocketClass *klass)
 						      G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   g_object_class_install_property (gobject_class, PROP_PROTOCOL,
-				   g_param_spec_int ("protocol",
+				   g_param_spec_enum ("protocol",
 						     P_("Socket protocol"),
 						     P_("The id of the protocol to use, or -1 for unknown"),
-						     G_MININT,
-						     G_MAXINT,
-						     -1,
+						      G_TYPE_SOCKET_PROTOCOL,
+						      G_SOCKET_PROTOCOL_UNKNOWN,
 						     G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   g_object_class_install_property (gobject_class, PROP_FD,
@@ -828,20 +749,22 @@ g_socket_initable_init (GInitable *initable,
  * g_socket_new:
  * @family: the socket family to use, e.g. %G_SOCKET_FAMILY_IPV4.
  * @type: the socket type to use.
- * @protocol_id: the id of the protocol to use, or 0 for default.
+ * @protocol: the id of the protocol to use, or 0 for default.
  * @error: #GError for error reporting, or %NULL to ignore.
  *
  * Creates a new #GSocket with the defined family, type and protocol.
- * If @protocol_id is 0 the default protocol type for the family and
- * type is used.
+ * If @protocol is 0 (%G_SOCKET_PROTOCOL_DEFAULT) the default protocol type
+ * for the family and type is used.
+ *
+ * The @protocol is a family and type specific int that specifies what
+ * kind of protocol to use. #GSocketProtocol lists several common ones.
+ * Many families only support one protocol, and use 0 for this, others
+ * support several and using 0 means to use the default protocol for
+ * the family and type.
  *
- * The @protocol_id is a family and type specific int that specifies what
- * kind of protocol to use. Many families only support one protocol,
- * and use 0 for this, others support several and using 0 means
- * to use the default protocol for the family and type. To use
- * other protocol, you can use g_socket_protocol_id_lookup_by_name()
- * to look up the protocol by name, or if you known the system specific
- * protocol id you can use that.
+ * The protocol id is passed directly to the operating
+ * system, so you can use protocols not listed in #GSocketProtocol if you
+ * know the protocol number used for it.
  *
  * Returns: a #GSocket or %NULL on error.
  *     Free the returned object with g_object_unref().
@@ -851,14 +774,14 @@ g_socket_initable_init (GInitable *initable,
 GSocket *
 g_socket_new (GSocketFamily family,
 	      GSocketType type,
-	      int protocol_id,
+	      GSocketProtocol protocol,
 	      GError **error)
 {
   return G_SOCKET (g_initable_new (G_TYPE_SOCKET,
 				   NULL, error,
 				   "family", family,
 				   "type", type,
-				   "protocol", protocol_id,
+				   "protocol", protocol,
 				   NULL));
 }
 
@@ -1089,7 +1012,7 @@ g_socket_get_socket_type (GSocket *socket)
 }
 
 /**
- * g_socket_get_protocol_id:
+ * g_socket_get_protocol:
  * @socket: a #GSocket.
  *
  * Gets the socket protocol id the socket was created with.
@@ -1099,8 +1022,8 @@ g_socket_get_socket_type (GSocket *socket)
  *
  * Since: 2.22
  **/
-gint
-g_socket_get_protocol_id (GSocket *socket)
+GSocketProtocol
+g_socket_get_protocol (GSocket *socket)
 {
   g_return_val_if_fail (G_IS_SOCKET (socket), -1);
 
@@ -1108,25 +1031,6 @@ g_socket_get_protocol_id (GSocket *socket)
 }
 
 /**
- * g_socket_get_protocol_name:
- * @socket: a #GSocket.
- *
- * Gets the socket protocol type name the socket was created with.
- * This can be %NULL if the socket was created with a NULL protocol.
- *
- * Returns: a string or %NULL, free with g_free
- *
- * Since: 2.22
- **/
-char *
-g_socket_get_protocol_name (GSocket *socket)
-{
-  g_return_val_if_fail (G_IS_SOCKET (socket), NULL);
-
-  return get_protocol_name (socket->priv->protocol);
-}
-
-/**
  * g_socket_get_fd:
  * @socket: a #GSocket.
  *
diff --git a/gio/gsocket.h b/gio/gsocket.h
index 7d5d0d48e..2ca90d287 100644
--- a/gio/gsocket.h
+++ b/gio/gsocket.h
@@ -76,15 +76,14 @@ struct _GSocket
 GType                  g_socket_get_type                (void) G_GNUC_CONST;
 GSocket *              g_socket_new                     (GSocketFamily            family,
 							 GSocketType              type,
-							 gint                     protocol_id,
+							 GSocketProtocol          protocol,
 							 GError                 **error);
 GSocket *              g_socket_new_from_fd             (gint                     fd,
 							 GError                 **error);
 int                    g_socket_get_fd                  (GSocket                 *socket);
 GSocketFamily          g_socket_get_family              (GSocket                 *socket);
 GSocketType            g_socket_get_socket_type         (GSocket                 *socket);
-gint                   g_socket_get_protocol_id         (GSocket                 *socket);
-char *                 g_socket_get_protocol_name       (GSocket                 *socket);
+GSocketProtocol        g_socket_get_protocol            (GSocket                 *socket);
 GSocketAddress *       g_socket_get_local_address       (GSocket                 *socket,
 							 GError                 **error);
 GSocketAddress *       g_socket_get_remote_address      (GSocket                 *socket,
@@ -163,8 +162,6 @@ GSource *              g_socket_create_source           (GSocket
 							 GIOCondition             condition,
 							 GCancellable            *cancellable);
 
-gint                  g_socket_protocol_id_lookup_by_name (const char            *protocol_name);
-
 G_END_DECLS
 
 #endif /* __G_SOCKET_H__ */
diff --git a/gio/gsocketclient.c b/gio/gsocketclient.c
index 922479347..944b73cb2 100644
--- a/gio/gsocketclient.c
+++ b/gio/gsocketclient.c
@@ -77,7 +77,7 @@ struct _GSocketClientPrivate
 {
   GSocketFamily family;
   GSocketType type;
-  char *protocol;
+  GSocketProtocol protocol;
   GSocketAddress *local_address;
 };
 
@@ -88,7 +88,6 @@ create_socket (GSocketClient  *client,
 {
   GSocketFamily family;
   GSocket *socket;
-  int proto;
 
   family = client->priv->family;
   if (family == G_SOCKET_FAMILY_INVALID &&
@@ -97,10 +96,9 @@ create_socket (GSocketClient  *client,
   if (family == G_SOCKET_FAMILY_INVALID)
     family = g_socket_address_get_family (dest_address);
 
-  proto = g_socket_protocol_id_lookup_by_name (client->priv->protocol);
   socket = g_socket_new (family,
 			 client->priv->type,
-			 proto,
+			 client->priv->protocol,
 			 error);
   if (socket == NULL)
     return NULL;
@@ -153,8 +151,6 @@ g_socket_client_finalize (GObject *object)
   if (client->priv->local_address)
     g_object_unref (client->priv->local_address);
 
-  g_free (client->priv->protocol);
-
   if (G_OBJECT_CLASS (g_socket_client_parent_class)->finalize)
     (*G_OBJECT_CLASS (g_socket_client_parent_class)->finalize) (object);
 }
@@ -178,7 +174,7 @@ g_socket_client_get_property (GObject    *object,
 	break;
 
       case PROP_PROTOCOL:
-	g_value_set_string (value, client->priv->protocol);
+	g_value_set_enum (value, client->priv->protocol);
 	break;
 
       case PROP_LOCAL_ADDRESS:
@@ -209,7 +205,7 @@ g_socket_client_set_property (GObject      *object,
       break;
 
     case PROP_PROTOCOL:
-      g_socket_client_set_protocol (client, g_value_get_string (value));
+      g_socket_client_set_protocol (client, g_value_get_enum (value));
       break;
 
     case PROP_LOCAL_ADDRESS:
@@ -317,11 +313,11 @@ g_socket_client_set_socket_type (GSocketClient *client,
  *
  * See g_socket_client_set_protocol() for details.
  *
- * Returns: a string or %NULL. don't free
+ * Returns: a #GSocketProtocol
  *
  * Since: 2.22
  **/
-const char *
+GSocketProtocol
 g_socket_client_get_protocol (GSocketClient *client)
 {
   return client->priv->protocol;
@@ -330,26 +326,25 @@ g_socket_client_get_protocol (GSocketClient *client)
 /**
  * g_socket_client_set_protocol:
  * @client: a #GSocketClient.
- * @protocol: a string, or %NULL
+ * @protocol: a #GSocketProtocol
  *
  * Sets the protocol of the socket client.
  * The sockets created by this object will use of the specified
  * protocol.
  *
- * If @protocol is %NULL that means to use the default
+ * If @protocol is %0 that means to use the default
  * protocol for the socket family and type.
  *
  * Since: 2.22
  **/
 void
-g_socket_client_set_protocol (GSocketClient        *client,
-			      const char           *protocol)
+g_socket_client_set_protocol (GSocketClient *client,
+			      GSocketProtocol protocol)
 {
-  if (g_strcmp0 (client->priv->protocol, protocol) == 0)
+  if (client->priv->protocol == protocol)
     return;
 
-  g_free (client->priv->protocol);
-  client->priv->protocol = g_strdup (protocol);
+  client->priv->protocol = protocol;
   g_object_notify (G_OBJECT (client), "protocol");
 }
 
@@ -429,11 +424,12 @@ g_socket_client_class_init (GSocketClientClass *class)
 						      G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   g_object_class_install_property (gobject_class, PROP_PROTOCOL,
-				   g_param_spec_string ("protocol",
-							P_("Socket protocol"),
-							P_("The protocol to use for socket construction, or %NULL for default"),
-							NULL,
-							G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+				   g_param_spec_enum ("protocol",
+						      P_("Socket protocol"),
+						      P_("The protocol to use for socket construction, or 0 for default"),
+						      G_TYPE_SOCKET_PROTOCOL,
+						      G_SOCKET_PROTOCOL_DEFAULT,
+						      G_PARAM_CONSTRUCT | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   g_object_class_install_property (gobject_class, PROP_LOCAL_ADDRESS,
 				   g_param_spec_object ("local-address",
diff --git a/gio/gsocketclient.h b/gio/gsocketclient.h
index b70246fa0..b04f57be5 100644
--- a/gio/gsocketclient.h
+++ b/gio/gsocketclient.h
@@ -76,9 +76,9 @@ void                    g_socket_client_set_family                      (GSocket
 GSocketType             g_socket_client_get_socket_type                 (GSocketClient        *client);
 void                    g_socket_client_set_socket_type                 (GSocketClient        *client,
 									 GSocketType           type);
-const char             *g_socket_client_get_protocol                    (GSocketClient        *client);
+GSocketProtocol         g_socket_client_get_protocol                    (GSocketClient        *client);
 void                    g_socket_client_set_protocol                    (GSocketClient        *client,
-									 const char           *protocol);
+									 GSocketProtocol       protocol);
 GSocketAddress         *g_socket_client_get_local_address               (GSocketClient        *client);
 void                    g_socket_client_set_local_address               (GSocketClient        *client,
 									 GSocketAddress       *address);
diff --git a/gio/gsocketconnection.c b/gio/gsocketconnection.c
index c14e3c1f3..3033c3a8e 100644
--- a/gio/gsocketconnection.c
+++ b/gio/gsocketconnection.c
@@ -483,7 +483,7 @@ g_socket_connection_factory_create_connection (GSocket *socket)
 
   type = g_socket_connection_factory_lookup_type (g_socket_get_family (socket),
 						  g_socket_get_socket_type (socket),
-						  g_socket_get_protocol_id (socket));
+						  g_socket_get_protocol (socket));
   return g_object_new (type, "socket", socket, NULL);
 }
 
diff --git a/gio/gsocketlistener.c b/gio/gsocketlistener.c
index 6fa5d709a..1d75a51a3 100644
--- a/gio/gsocketlistener.c
+++ b/gio/gsocketlistener.c
@@ -246,9 +246,9 @@ g_socket_listener_add_socket (GSocketListener *listener,
 /**
  * g_socket_listener_add_address:
  * @listener: a #GSocketListener
- * @address: a #GSocketAddres
+ * @address: a #GSocketAddress
  * @type: a #GSocketType
- * @protocol: a protocol name, or %NULL
+ * @protocol: a #GSocketProtocol
  * @source_object: Optional #GObject identifying this source
  * @error: #GError for error reporting, or %NULL to ignore.
  *
@@ -269,7 +269,7 @@ gboolean
 g_socket_listener_add_address (GSocketListener *listener,
 			       GSocketAddress *address,
 			       GSocketType type,
-			       const char *protocol,
+			       GSocketProtocol protocol,
 			       GObject *source_object,
 			       GError **error)
 {
@@ -280,8 +280,7 @@ g_socket_listener_add_address (GSocketListener *listener,
     return FALSE;
 
   family = g_socket_address_get_family (address);
-  socket = g_socket_new (family, type,
-			 g_socket_protocol_id_lookup_by_name (protocol), error);
+  socket = g_socket_new (family, type, protocol, error);
   if (socket == NULL)
     return FALSE;
 
@@ -347,7 +346,7 @@ g_socket_listener_add_inet_port (GSocketListener *listener,
   if (!g_socket_listener_add_address (listener,
 				      address6,
 				      G_SOCKET_TYPE_STREAM,
-				      NULL,
+				      G_SOCKET_PROTOCOL_DEFAULT,
 				      source_object,
 				      NULL))
     {
@@ -356,7 +355,7 @@ g_socket_listener_add_inet_port (GSocketListener *listener,
       res = g_socket_listener_add_address (listener,
 					   address4,
 					   G_SOCKET_TYPE_STREAM,
-					   NULL,
+					   G_SOCKET_PROTOCOL_DEFAULT,
 					   source_object,
 					   error);
     }
@@ -368,7 +367,7 @@ g_socket_listener_add_inet_port (GSocketListener *listener,
       g_socket_listener_add_address (listener,
 				     address4,
 				     G_SOCKET_TYPE_STREAM,
-				     NULL,
+				     G_SOCKET_PROTOCOL_DEFAULT,
 				     source_object,
 				     NULL);
     }
diff --git a/gio/gsocketlistener.h b/gio/gsocketlistener.h
index 9a13209a2..da51a760d 100644
--- a/gio/gsocketlistener.h
+++ b/gio/gsocketlistener.h
@@ -90,7 +90,7 @@ gboolean                g_socket_listener_add_socket                    (GSocket
 gboolean                g_socket_listener_add_address                   (GSocketListener      *listener,
                                                                          GSocketAddress      *address,
 									 GSocketType          type,
-									 const char          *protocol,
+									 GSocketProtocol      protocol,
 									 GObject             *source_object,
 									 GError             **error);
 gboolean                g_socket_listener_add_inet_port                 (GSocketListener      *listener,
diff --git a/gio/gtcpconnection.c b/gio/gtcpconnection.c
index 6c4e320bf..62a90b3ad 100644
--- a/gio/gtcpconnection.c
+++ b/gio/gtcpconnection.c
@@ -41,19 +41,19 @@ G_DEFINE_TYPE_WITH_CODE (GTcpConnection, g_tcp_connection,
   g_socket_connection_factory_register_type (g_define_type_id,
 					     G_SOCKET_FAMILY_IPV4,
 					     G_SOCKET_TYPE_STREAM,
-					     0);
+					     G_SOCKET_PROTOCOL_DEFAULT);
   g_socket_connection_factory_register_type (g_define_type_id,
 					     G_SOCKET_FAMILY_IPV6,
 					     G_SOCKET_TYPE_STREAM,
-					     0);
+					     G_SOCKET_PROTOCOL_DEFAULT);
   g_socket_connection_factory_register_type (g_define_type_id,
 					     G_SOCKET_FAMILY_IPV4,
 					     G_SOCKET_TYPE_STREAM,
-					     g_socket_protocol_id_lookup_by_name ("tcp"));
+					     G_SOCKET_PROTOCOL_TCP);
   g_socket_connection_factory_register_type (g_define_type_id,
 					     G_SOCKET_FAMILY_IPV6,
 					     G_SOCKET_TYPE_STREAM,
-					     g_socket_protocol_id_lookup_by_name ("tcp"));
+					     G_SOCKET_PROTOCOL_TCP);
 			 );
 
 static gboolean g_tcp_connection_close       (GIOStream            *stream,
diff --git a/gio/gunixconnection.c b/gio/gunixconnection.c
index 1877f3772..47d172396 100644
--- a/gio/gunixconnection.c
+++ b/gio/gunixconnection.c
@@ -43,7 +43,7 @@ G_DEFINE_TYPE_WITH_CODE (GUnixConnection, g_unix_connection,
   g_socket_connection_factory_register_type (g_define_type_id,
 					     G_SOCKET_FAMILY_UNIX,
 					     G_SOCKET_TYPE_STREAM,
-					     0);
+					     G_SOCKET_PROTOCOL_DEFAULT);
 			 );
 
 /**