1 /* GIO - GLib Input, Output and Streaming Library
2  *
3  * Copyright (C) 2008 Red Hat, Inc.
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General
16  * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include "config.h"
20 #include "gsocketconnectable.h"
21 #include "glibintl.h"
22 
23 
24 /**
25  * SECTION:gsocketconnectable
26  * @short_description: Interface for potential socket endpoints
27  * @include: gio/gio.h
28  *
29  * Objects that describe one or more potential socket endpoints
30  * implement #GSocketConnectable. Callers can then use
31  * g_socket_connectable_enumerate() to get a #GSocketAddressEnumerator
32  * to try out each socket address in turn until one succeeds, as shown
33  * in the sample code below.
34  *
35  * |[<!-- language="C" -->
36  * MyConnectionType *
37  * connect_to_host (const char    *hostname,
38  *                  guint16        port,
39  *                  GCancellable  *cancellable,
40  *                  GError       **error)
41  * {
42  *   MyConnection *conn = NULL;
43  *   GSocketConnectable *addr;
44  *   GSocketAddressEnumerator *enumerator;
45  *   GSocketAddress *sockaddr;
46  *   GError *conn_error = NULL;
47  *
48  *   addr = g_network_address_new (hostname, port);
49  *   enumerator = g_socket_connectable_enumerate (addr);
50  *   g_object_unref (addr);
51  *
52  *   // Try each sockaddr until we succeed. Record the first connection error,
53  *   // but not any further ones (since they'll probably be basically the same
54  *   // as the first).
55  *   while (!conn && (sockaddr = g_socket_address_enumerator_next (enumerator, cancellable, error))
56  *     {
57  *       conn = connect_to_sockaddr (sockaddr, conn_error ? NULL : &conn_error);
58  *       g_object_unref (sockaddr);
59  *     }
60  *   g_object_unref (enumerator);
61  *
62  *   if (conn)
63  *     {
64  *       if (conn_error)
65  *         {
66  *           // We couldn't connect to the first address, but we succeeded
67  *           // in connecting to a later address.
68  *           g_error_free (conn_error);
69  *         }
70  *       return conn;
71  *     }
72  *   else if (error)
73  *     {
74  *       /// Either initial lookup failed, or else the caller cancelled us.
75  *       if (conn_error)
76  *         g_error_free (conn_error);
77  *       return NULL;
78  *     }
79  *   else
80  *     {
81  *       g_error_propagate (error, conn_error);
82  *       return NULL;
83  *     }
84  * }
85  * ]|
86  */
87 
88 
89 typedef GSocketConnectableIface GSocketConnectableInterface;
G_DEFINE_INTERFACE(GSocketConnectable,g_socket_connectable,G_TYPE_OBJECT)90 G_DEFINE_INTERFACE (GSocketConnectable, g_socket_connectable, G_TYPE_OBJECT)
91 
92 static void
93 g_socket_connectable_default_init (GSocketConnectableInterface *iface)
94 {
95 }
96 
97 /**
98  * g_socket_connectable_enumerate:
99  * @connectable: a #GSocketConnectable
100  *
101  * Creates a #GSocketAddressEnumerator for @connectable.
102  *
103  * Returns: (transfer full): a new #GSocketAddressEnumerator.
104  *
105  * Since: 2.22
106  */
107 GSocketAddressEnumerator *
g_socket_connectable_enumerate(GSocketConnectable * connectable)108 g_socket_connectable_enumerate (GSocketConnectable *connectable)
109 {
110   GSocketConnectableIface *iface;
111 
112   g_return_val_if_fail (G_IS_SOCKET_CONNECTABLE (connectable), NULL);
113 
114   iface = G_SOCKET_CONNECTABLE_GET_IFACE (connectable);
115 
116   return (* iface->enumerate) (connectable);
117 }
118 
119 /**
120  * g_socket_connectable_proxy_enumerate:
121  * @connectable: a #GSocketConnectable
122  *
123  * Creates a #GSocketAddressEnumerator for @connectable that will
124  * return a #GProxyAddress for each of its addresses that you must connect
125  * to via a proxy.
126  *
127  * If @connectable does not implement
128  * g_socket_connectable_proxy_enumerate(), this will fall back to
129  * calling g_socket_connectable_enumerate().
130  *
131  * Returns: (transfer full): a new #GSocketAddressEnumerator.
132  *
133  * Since: 2.26
134  */
135 GSocketAddressEnumerator *
g_socket_connectable_proxy_enumerate(GSocketConnectable * connectable)136 g_socket_connectable_proxy_enumerate (GSocketConnectable *connectable)
137 {
138   GSocketConnectableIface *iface;
139 
140   g_return_val_if_fail (G_IS_SOCKET_CONNECTABLE (connectable), NULL);
141 
142   iface = G_SOCKET_CONNECTABLE_GET_IFACE (connectable);
143 
144   if (iface->proxy_enumerate)
145     return (* iface->proxy_enumerate) (connectable);
146   else
147     return (* iface->enumerate) (connectable);
148 }
149 
150 /**
151  * g_socket_connectable_to_string:
152  * @connectable: a #GSocketConnectable
153  *
154  * Format a #GSocketConnectable as a string. This is a human-readable format for
155  * use in debugging output, and is not a stable serialization format. It is not
156  * suitable for use in user interfaces as it exposes too much information for a
157  * user.
158  *
159  * If the #GSocketConnectable implementation does not support string formatting,
160  * the implementation’s type name will be returned as a fallback.
161  *
162  * Returns: (transfer full): the formatted string
163  *
164  * Since: 2.48
165  */
166 gchar *
g_socket_connectable_to_string(GSocketConnectable * connectable)167 g_socket_connectable_to_string (GSocketConnectable *connectable)
168 {
169   GSocketConnectableIface *iface;
170 
171   g_return_val_if_fail (G_IS_SOCKET_CONNECTABLE (connectable), NULL);
172 
173   iface = G_SOCKET_CONNECTABLE_GET_IFACE (connectable);
174 
175   if (iface->to_string != NULL)
176     return iface->to_string (connectable);
177   else
178     return g_strdup (G_OBJECT_TYPE_NAME (connectable));
179 }
180