/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2010 Collabora, Ltd.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* Author: Nicolas Dufresne <nicolas.dufresne@collabora.co.uk>
*/
#include "config.h"
#include "gsocks4aproxy.h"
#include <string.h>
#include "giomodule.h"
#include "giomodule-priv.h"
#include "giostream.h"
#include "ginetaddress.h"
#include "ginputstream.h"
#include "glibintl.h"
#include "goutputstream.h"
#include "gproxy.h"
#include "gproxyaddress.h"
#include "gtask.h"
#define SOCKS4_VERSION 4
#define SOCKS4_CMD_CONNECT 1
#define SOCKS4_CMD_BIND 2
#define SOCKS4_MAX_LEN 255
#define SOCKS4_REP_VERSION 0
#define SOCKS4_REP_GRANTED 90
#define SOCKS4_REP_REJECTED 91
#define SOCKS4_REP_NO_IDENT 92
#define SOCKS4_REP_BAD_IDENT 93
static void g_socks4a_proxy_iface_init (GProxyInterface *proxy_iface);
#define g_socks4a_proxy_get_type _g_socks4a_proxy_get_type
G_DEFINE_TYPE_WITH_CODE (GSocks4aProxy, g_socks4a_proxy, G_TYPE_OBJECT,
G_IMPLEMENT_INTERFACE (G_TYPE_PROXY,
g_socks4a_proxy_iface_init)
_g_io_modules_ensure_extension_points_registered ();
g_io_extension_point_implement (G_PROXY_EXTENSION_POINT_NAME,
g_define_type_id,
"socks4a",
0))
static void
g_socks4a_proxy_finalize (GObject *object)
{
/* must chain up */
G_OBJECT_CLASS (g_socks4a_proxy_parent_class)->finalize (object);
}
static void
g_socks4a_proxy_init (GSocks4aProxy *proxy)
{
proxy->supports_hostname = TRUE;
}
/* |-> SOCKSv4a only
* +----+----+----+----+----+----+----+----+----+----+....+----+------+....+------+
* | VN | CD | DSTPORT | DSTIP | USERID |NULL| HOST | | NULL |
* +----+----+----+----+----+----+----+----+----+----+....+----+------+....+------+
* 1 1 2 4 variable 1 variable
*/
#define SOCKS4_CONN_MSG_LEN (9 + SOCKS4_MAX_LEN * 2)
static gint
set_connect_msg (guint8 *msg,
const gchar *hostname,
guint16 port,
const char *username,
GError **error)
{
GInetAddress *addr;
guint len = 0;
gsize addr_len;
gboolean is_ip;
const gchar *ip;
msg[len++] = SOCKS4_VERSION;
msg[len++] = SOCKS4_CMD_CONNECT;
{
guint16 hp = g_htons (port);
memcpy (msg + len, &hp, 2);
len += 2;
}
is_ip = g_hostname_is_ip_address (hostname);
if (is_ip)
ip = hostname;
else
ip = "0.0.0.1";
addr = g_inet_address_new_from_string (ip);
addr_len = g_inet_address_get_native_size (addr);
if (addr_len != 4)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
_("SOCKSv4 does not support IPv6 address “%s”"),
ip);
g_object_unref (addr);
return -1;
}
memcpy (msg + len, g_inet_address_to_bytes (addr), addr_len);
len += addr_len;
g_object_unref (addr);
if (username)
{
gsize user_len = strlen (username);
if (user_len > SOCKS4_MAX_LEN)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
_("Username is too long for SOCKSv4 protocol"));
return -1;
}
memcpy (msg + len, username, user_len);
len += user_len;
}
msg[len++] = '\0';
if (!is_ip)
{
gsize host_len = strlen (hostname);
if (host_len > SOCKS4_MAX_LEN)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
_("Hostname “%s” is too long for SOCKSv4 protocol"),
hostname);
return -1;
}
memcpy (msg + len, hostname, host_len);
len += host_len;
msg[len++] = '\0';
}
return len;
}
/*
* +----+----+----+----+----+----+----+----+
* | VN | CD | DSTPORT | DSTIP |
* +----+----+----+----+----+----+----+----+
* 1 1 2 4
*/
#define SOCKS4_CONN_REP_LEN 8
static gboolean
parse_connect_reply (const guint8 *data, GError **error)
{
if (data[0] != SOCKS4_REP_VERSION)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
_("The server is not a SOCKSv4 proxy server."));
return FALSE;
}
if (data[1] != SOCKS4_REP_GRANTED)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
_("Connection through SOCKSv4 server was rejected"));
return FALSE;
}
return TRUE;
}
static GIOStream *
g_socks4a_proxy_connect (GProxy *proxy,
GIOStream *io_stream,
GProxyAddress *proxy_address,
GCancellable *cancellable,
GError **error)
{
GInputStream *in;
GOutputStream *out;
const gchar *hostname;
guint16 port;
const gchar *username;
hostname = g_proxy_address_get_destination_hostname (proxy_address);
port = g_proxy_address_get_destination_port (proxy_address);
username = g_proxy_address_get_username (proxy_address);
in = g_io_stream_get_input_stream (io_stream);
out = g_io_stream_get_output_stream (io_stream);
/* Send SOCKS4 connection request */
{
guint8 msg[SOCKS4_CONN_MSG_LEN];
gint len;
len = set_connect_msg (msg, hostname, port, username, error);
if (len < 0)
goto error;
if (!g_output_stream_write_all (out, msg, len, NULL,
cancellable, error))
goto error;
}
/* Read SOCKS4 response */
{
guint8 data[SOCKS4_CONN_REP_LEN];
if (!g_input_stream_read_all (in, data, SOCKS4_CONN_REP_LEN, NULL,
cancellable, error))
goto error;
if (!parse_connect_reply (data, error))
goto error;
}
return g_object_ref (io_stream);
error:
return NULL;
}
typedef struct
{
GIOStream *io_stream;
/* For connecting */
guint8 *buffer;
gssize length;
gssize offset;
} ConnectAsyncData;
static void connect_msg_write_cb (GObject *source,
GAsyncResult *result,
gpointer user_data);
static void connect_reply_read_cb (GObject *source,
GAsyncResult *result,
gpointer user_data);
static void
free_connect_data (ConnectAsyncData *data)
{
g_object_unref (data->io_stream);
g_slice_free (ConnectAsyncData, data);
}
static void
do_read (GAsyncReadyCallback callback, GTask *task, ConnectAsyncData *data)
{
GInputStream *in;
in = g_io_stream_get_input_stream (data->io_stream);
g_input_stream_read_async (in,
data->buffer + data->offset,
data->length - data->offset,
g_task_get_priority (task),
g_task_get_cancellable (task),
callback, task);
}
static void
do_write (GAsyncReadyCallback callback, GTask *task, ConnectAsyncData *data)
{
GOutputStream *out;
out = g_io_stream_get_output_stream (data->io_stream);
g_output_stream_write_async (out,
data->buffer + data->offset,
data->length - data->offset,
g_task_get_priority (task),
g_task_get_cancellable (task),
callback, task);
}
static void
g_socks4a_proxy_connect_async (GProxy *proxy,
GIOStream *io_stream,
GProxyAddress *proxy_address,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GError *error = NULL;
GTask *task;
ConnectAsyncData *data;
const gchar *hostname;
guint16 port;
const gchar *username;
data = g_slice_new0 (ConnectAsyncData);
data->io_stream = g_object_ref (io_stream);
task = g_task_new (proxy, cancellable, callback, user_data);
g_task_set_source_tag (task, g_socks4a_proxy_connect_async);
g_task_set_task_data (task, data, (GDestroyNotify) free_connect_data);
hostname = g_proxy_address_get_destination_hostname (proxy_address);
port = g_proxy_address_get_destination_port (proxy_address);
username = g_proxy_address_get_username (proxy_address);
data->buffer = g_malloc0 (SOCKS4_CONN_MSG_LEN);
data->length = set_connect_msg (data->buffer,
hostname, port, username,
&error);
data->offset = 0;
if (data->length < 0)
{
g_task_return_error (task, error);
g_object_unref (task);
}
else
{
do_write (connect_msg_write_cb, task, data);
}
}
static void
connect_msg_write_cb (GObject *source,
GAsyncResult *result,
gpointer user_data)
{
GTask *task = user_data;
ConnectAsyncData *data = g_task_get_task_data (task);
GError *error = NULL;
gssize written;
written = g_output_stream_write_finish (G_OUTPUT_STREAM (source),
result, &error);
if (written < 0)
{
g_task_return_error (task, error);
g_object_unref (task);
return;
}
data->offset += written;
if (data->offset == data->length)
{
g_free (data->buffer);
data->buffer = g_malloc0 (SOCKS4_CONN_REP_LEN);
data->length = SOCKS4_CONN_REP_LEN;
data->offset = 0;
do_read (connect_reply_read_cb, task, data);
}
else
{
do_write (connect_msg_write_cb, task, data);
}
}
static void
connect_reply_read_cb (GObject *source,
GAsyncResult *result,
gpointer user_data)
{
GTask *task = user_data;
ConnectAsyncData *data = g_task_get_task_data (task);
GError *error = NULL;
gssize read;
read = g_input_stream_read_finish (G_INPUT_STREAM (source),
result, &error);
if (read < 0)
{
g_task_return_error (task, error);
g_object_unref (task);
return;
}
data->offset += read;
if (data->offset == data->length)
{
if (!parse_connect_reply (data->buffer, &error))
{
g_task_return_error (task, error);
g_object_unref (task);
return;
}
else
{
g_task_return_pointer (task, g_object_ref (data->io_stream), g_object_unref);
g_object_unref (task);
return;
}
}
else
{
do_read (connect_reply_read_cb, task, data);
}
}
static GIOStream *g_socks4a_proxy_connect_finish (GProxy *proxy,
GAsyncResult *result,
GError **error);
static GIOStream *
g_socks4a_proxy_connect_finish (GProxy *proxy,
GAsyncResult *result,
GError **error)
{
return g_task_propagate_pointer (G_TASK (result), error);
}
static gboolean
g_socks4a_proxy_supports_hostname (GProxy *proxy)
{
return G_SOCKS4A_PROXY (proxy)->supports_hostname;
}
static void
g_socks4a_proxy_class_init (GSocks4aProxyClass *class)
{
GObjectClass *object_class;
object_class = (GObjectClass *) class;
object_class->finalize = g_socks4a_proxy_finalize;
}
static void
g_socks4a_proxy_iface_init (GProxyInterface *proxy_iface)
{
proxy_iface->connect = g_socks4a_proxy_connect;
proxy_iface->connect_async = g_socks4a_proxy_connect_async;
proxy_iface->connect_finish = g_socks4a_proxy_connect_finish;
proxy_iface->supports_hostname = g_socks4a_proxy_supports_hostname;
}