[glib] Store protocol by id, add lookup function for name

[Alexander Larsson <alexl src gnome org>]

commit f662e7e86bc27102948683c0925815efefb43bbc
Author: Alexander Larsson <alexl redhat com>
Date:   Fri May 15 09:10:23 2009 +0200

    Store protocol by id, add lookup function for name
    
    We want to use the protocol id for lookup in the GSocketConnection
    code, so we expose it. We also make GSocket store the protocol
    as an int for less memory use and to allow platform specific protocols
    to be specified.
    
    Also added g_socket_protocol_id_lookup_by_name() to allow the higher
    level code to specify the name by string, and g_socket_get_protocol_name()
    to get it.
---
 gio/gio.symbols |    4 +-
 gio/gsocket.c   |  178 +++++++++++++++++++++++++++++++++++++++++--------------
 gio/gsocket.h   |    6 +-
 3 files changed, 141 insertions(+), 47 deletions(-)

diff --git a/gio/gio.symbols b/gio/gio.symbols
index d24979e..3078b3b 100644
--- a/gio/gio.symbols
+++ b/gio/gio.symbols
@@ -1077,7 +1077,9 @@ g_socket_get_fd
 g_socket_get_keepalive
 g_socket_get_listen_backlog
 g_socket_get_local_address
-g_socket_get_protocol
+g_socket_get_protocol_id
+g_socket_get_protocol_name
+g_socket_protocol_id_lookup_by_name
 g_socket_get_remote_address
 g_socket_get_socket_type
 g_socket_is_closed
diff --git a/gio/gsocket.c b/gio/gsocket.c
index c03cdb7..8d5069f 100644
--- a/gio/gsocket.c
+++ b/gio/gsocket.c
@@ -28,6 +28,8 @@
 #include "config.h"
 
 #include <errno.h>
+#include <string.h>
+#include <stdlib.h>
 
 #ifndef G_OS_WIN32
 # include <netinet/in.h>
@@ -132,7 +134,7 @@ struct _GSocketPrivate
 {
   GSocketFamily   family;
   GSocketType     type;
-  char           *protocol;
+  gint            protocol;
   gint            fd;
   gint            listen_backlog;
   GError         *construct_error;
@@ -404,16 +406,92 @@ 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,
-			const char     *protocol_name,
+			int             protocol_id,
 			GError        **error)
 {
   gint native_type;
   gint fd;
-  gint protocol;
-  struct protoent *protoent;
 
   switch (type)
     {
@@ -433,41 +511,24 @@ g_socket_create_socket (GSocketFamily   family,
       g_assert_not_reached ();
     }
 
-  protocol = 0;
-  if (protocol_name)
+  if (protocol_id == -1)
     {
-#ifdef HAVE_GETPROTOBYNAME_R
-      char buffer[1024];
-      struct protoent my_protoent;
-
-      protoent = NULL;
-      getprotobyname_r (protocol_name,
-			&my_protoent, buffer, sizeof (buffer),
-			&protoent);
-#else
-      protoent = getprotobyname (protocol_name);
-#endif
-      if (protoent == NULL)
-	{
-	  g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
-		       _("unable to create socket: Protocol %s not supported"),
-		       protocol_name);
-	  return -1;
-	}
-      protocol = protoent->p_proto;
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_ARGUMENT,
+		   _("Unable to create socket: %s"), _("Unknown protocol was specified"));
+      return -1;
     }
 
 #ifdef SOCK_CLOEXEC
   native_type |= SOCK_CLOEXEC;
 #endif
-  fd = socket (family, native_type, protocol);
+  fd = socket (family, native_type, protocol_id);
 
   if (fd < 0)
     {
       int errsv = get_socket_errno ();
 
       g_set_error (error, G_IO_ERROR, socket_io_error_from_errno (errsv),
-		   _("unable to create socket: %s"), socket_strerror (errsv));
+		   _("Unable to create socket: %s"), socket_strerror (errsv));
     }
 
 #ifndef G_OS_WIN32
@@ -533,7 +594,7 @@ g_socket_get_property (GObject    *object,
 	break;
 
       case PROP_PROTOCOL:
-	g_value_set_string (value, socket->priv->protocol);
+	g_value_set_int (value, socket->priv->protocol);
 	break;
 
       case PROP_FD:
@@ -584,7 +645,7 @@ g_socket_set_property (GObject      *object,
 	break;
 
       case PROP_PROTOCOL:
-	socket->priv->protocol = g_value_dup_string (value);
+	socket->priv->protocol = g_value_get_int (value);
 	break;
 
       case PROP_FD:
@@ -619,8 +680,6 @@ g_socket_finalize (GObject *object)
       !socket->priv->closed)
     g_socket_close (socket, NULL);
 
-  g_free (socket->priv->protocol);
-
 #ifdef G_OS_WIN32
   g_assert (socket->priv->requested_conditions == NULL);
 #endif
@@ -684,11 +743,13 @@ 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_string ("protocol",
-							P_("Socket protocol"),
-							P_("The name of the protocol to use, or NULL"),
-							NULL,
-							G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+				   g_param_spec_int ("protocol",
+						     P_("Socket protocol"),
+						     P_("The id of the protocol to use, or -1 for unknown"),
+						     G_MININT,
+						     G_MAXINT,
+						     -1,
+						     G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
   g_object_class_install_property (gobject_class, PROP_FD,
 				   g_param_spec_int ("fd",
@@ -794,13 +855,21 @@ 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: the name of the protocol to use, or %NULL.
+ * @protocol_id: 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 is %NULL 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. 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.
+ *
  * Returns: a #GSocket or %NULL on error.
  *     Free the returned object with g_object_unref().
  *
@@ -809,14 +878,14 @@ g_socket_initable_init (GInitable *initable,
 GSocket *
 g_socket_new (GSocketFamily family,
 	      GSocketType type,
-	      const char *protocol,
+	      int protocol_id,
 	      GError **error)
 {
   return G_SOCKET (g_initable_new (G_TYPE_SOCKET,
 				   NULL, error,
 				   "family", family,
 				   "type", type,
-				   "protocol", protocol,
+				   "protocol", protocol_id,
 				   NULL));
 }
 
@@ -1043,22 +1112,41 @@ g_socket_get_socket_type (GSocket *socket)
 }
 
 /**
- * g_socket_get_protocol:
+ * g_socket_get_protocol_id:
+ * @socket: a #GSocket.
+ *
+ * Gets the socket protocol id the socket was created with.
+ * In case the protocol is unknown, -1 is returned.
+ *
+ * Returns: a protocol id, or -1 if unknown
+ *
+ * Since: 2.22
+ **/
+gint
+g_socket_get_protocol_id (GSocket *socket)
+{
+  g_return_val_if_fail (G_IS_SOCKET (socket), -1);
+
+  return socket->priv->protocol;
+}
+
+/**
+ * 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, do not free
+ * Returns: a string or %NULL, free with g_free
  *
  * Since: 2.22
  **/
-const char *
-g_socket_get_protocol (GSocket *socket)
+char *
+g_socket_get_protocol_name (GSocket *socket)
 {
   g_return_val_if_fail (G_IS_SOCKET (socket), NULL);
 
-  return socket->priv->protocol;
+  return get_protocol_name (socket->priv->protocol);
 }
 
 /**
@@ -1388,6 +1476,8 @@ g_socket_accept (GSocket       *socket,
       close (ret);
 #endif
     }
+  else
+    new_socket->priv->protocol = socket->priv->protocol;
 
   return new_socket;
 }
diff --git a/gio/gsocket.h b/gio/gsocket.h
index b389333..9a6a85d 100644
--- a/gio/gsocket.h
+++ b/gio/gsocket.h
@@ -76,14 +76,15 @@ struct _GSocket
 GType                  g_socket_get_type                (void) G_GNUC_CONST;
 GSocket *              g_socket_new                     (GSocketFamily            family,
 							 GSocketType              type,
-							 const char              *protocol,
+							 gint                     protocol_id,
 							 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);
-const char *           g_socket_get_protocol            (GSocket                 *socket);
+gint                   g_socket_get_protocol_id         (GSocket                 *socket);
+char *                 g_socket_get_protocol_name       (GSocket                 *socket);
 GSocketAddress *       g_socket_get_local_address       (GSocket                 *socket,
 							 GError                 **error);
 GSocketAddress *       g_socket_get_remote_address      (GSocket                 *socket,
@@ -166,6 +167,7 @@ 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