/* 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 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 . * * Author: Nicolas Dufresne */ #include "config.h" #include "gsocks4aproxy.h" #include #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 ā€œ%sā€"), 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 ā€œ%sā€ 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; }