libnice/socket/socks5.c
Olivier Crête b58e852de6 socket: Assert trying to use free'd socket
Cleanly returnign makes no sense and may hide
worse problems.
2016-06-02 19:23:49 -04:00

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/*
* This file is part of the Nice GLib ICE library.
*
* (C) 2008 Collabora Ltd.
* Contact: Youness Alaoui
* (C) 2008 Nokia Corporation. All rights reserved.
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Nice GLib ICE library.
*
* The Initial Developers of the Original Code are Collabora Ltd and Nokia
* Corporation. All Rights Reserved.
*
* Contributors:
* Youness Alaoui, Collabora Ltd.
*
* Alternatively, the contents of this file may be used under the terms of the
* the GNU Lesser General Public License Version 2.1 (the "LGPL"), in which
* case the provisions of LGPL are applicable instead of those above. If you
* wish to allow use of your version of this file only under the terms of the
* LGPL and not to allow others to use your version of this file under the
* MPL, indicate your decision by deleting the provisions above and replace
* them with the notice and other provisions required by the LGPL. If you do
* not delete the provisions above, a recipient may use your version of this
* file under either the MPL or the LGPL.
*/
/*
* Implementation of TCP relay socket interface using TCP Berkeley sockets. (See
* http://en.wikipedia.org/wiki/Berkeley_sockets.)
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "socks5.h"
#include "agent-priv.h"
#include "socket-priv.h"
#include <string.h>
#ifndef G_OS_WIN32
#include <unistd.h>
#endif
typedef enum {
SOCKS_STATE_INIT,
SOCKS_STATE_AUTH,
SOCKS_STATE_CONNECT,
SOCKS_STATE_CONNECTED,
SOCKS_STATE_ERROR
} SocksState;
typedef struct {
SocksState state;
NiceSocket *base_socket;
NiceAddress addr;
gchar *username;
gchar *password;
GQueue send_queue;
} Socks5Priv;
static void socket_close (NiceSocket *sock);
static gint socket_recv_messages (NiceSocket *sock,
NiceInputMessage *recv_messages, guint n_recv_messages);
static gint socket_send_messages (NiceSocket *sock, const NiceAddress *to,
const NiceOutputMessage *messages, guint n_messages);
static gint socket_send_messages_reliable (NiceSocket *sock,
const NiceAddress *to, const NiceOutputMessage *messages, guint n_messages);
static gboolean socket_is_reliable (NiceSocket *sock);
static gboolean socket_can_send (NiceSocket *sock, NiceAddress *addr);
static void socket_set_writable_callback (NiceSocket *sock,
NiceSocketWritableCb callback, gpointer user_data);
static gboolean socket_is_based_on (NiceSocket *sock, NiceSocket *other);
NiceSocket *
nice_socks5_socket_new (NiceSocket *base_socket,
NiceAddress *addr, gchar *username, gchar *password)
{
Socks5Priv *priv;
NiceSocket *sock = NULL;
if (addr) {
sock = g_slice_new0 (NiceSocket);
sock->priv = priv = g_slice_new0 (Socks5Priv);
priv->base_socket = base_socket;
priv->addr = *addr;
priv->username = g_strdup (username);
priv->password = g_strdup (password);
sock->type = NICE_SOCKET_TYPE_SOCKS5;
sock->fileno = priv->base_socket->fileno;
sock->addr = priv->base_socket->addr;
sock->send_messages = socket_send_messages;
sock->send_messages_reliable = socket_send_messages_reliable;
sock->recv_messages = socket_recv_messages;
sock->is_reliable = socket_is_reliable;
sock->can_send = socket_can_send;
sock->set_writable_callback = socket_set_writable_callback;
sock->is_based_on = socket_is_based_on;
sock->close = socket_close;
/* Send SOCKS5 handshake */
{
gchar msg[4];
gint len = 3;
msg[0] = 0x05; /* SOCKS version */
msg[1] = 0x01; /* number of methods supported */
msg[2] = 0x00; /* no authentication method*/
g_debug ("user/pass : %s - %s", username, password);
/* add support for authentication method */
if (username || password) {
msg[1] = 0x02; /* number of methods supported */
msg[3] = 0x02; /* authentication method */
len++;
}
/* We send 'to' NULL because it will always be to an already connected
* TCP base socket, which ignores the destination */
nice_socket_send_reliable (priv->base_socket, NULL, len, msg);
priv->state = SOCKS_STATE_INIT;
}
}
return sock;
}
static void
socket_close (NiceSocket *sock)
{
Socks5Priv *priv = sock->priv;
if (priv->base_socket)
nice_socket_free (priv->base_socket);
if (priv->username)
g_free (priv->username);
if (priv->password)
g_free (priv->password);
nice_socket_free_send_queue (&priv->send_queue);
g_slice_free(Socks5Priv, sock->priv);
sock->priv = NULL;
}
static gint
socket_recv_messages (NiceSocket *sock,
NiceInputMessage *recv_messages, guint n_recv_messages)
{
Socks5Priv *priv = sock->priv;
guint i;
gint ret = -1;
/* Make sure socket has not been freed: */
g_assert (sock->priv != NULL);
switch (priv->state) {
case SOCKS_STATE_CONNECTED:
/* Common case: fast pass-through to the base socket once were
* connected. */
if (priv->base_socket) {
ret = nice_socket_recv_messages (priv->base_socket,
recv_messages, n_recv_messages);
}
if (ret <= 0)
return ret;
/* After successfully receiving into at least one NiceInputMessage,
* update the from address in each valid NiceInputMessage. */
for (i = 0; i < (guint) ret; i++) {
if (recv_messages[i].from != NULL)
*recv_messages[i].from = priv->addr;
}
return ret;
case SOCKS_STATE_INIT:
{
guint8 data[2];
GInputVector local_recv_buf = { data, sizeof (data) };
NiceInputMessage local_recv_message = { &local_recv_buf, 1, NULL, 0 };
nice_debug ("Socks5 state Init");
if (priv->base_socket) {
ret = nice_socket_recv_messages (priv->base_socket,
&local_recv_message, 1);
}
if (ret <= 0) {
return ret;
} else if (ret == 1 && local_recv_buf.size == sizeof(data)) {
if (data[0] == 0x05) {
if (data[1] == 0x02) {
gchar msg[515];
gint len = 0;
if (priv->username || priv->password) {
gint ulen = 0;
gint plen = 0;
if (priv->username)
ulen = strlen (priv->username);
if (ulen > 255) {
nice_debug ("Socks5 username length > 255");
goto error;
}
if (priv->password)
plen = strlen (priv->password);
if (plen > 255) {
nice_debug ("Socks5 password length > 255");
goto error;
}
msg[len++] = 0x01; /* auth version */
msg[len++] = ulen; /* username length */
if (ulen > 0)
memcpy (msg + len, priv->username, ulen); /* Username */
len += ulen;
msg[len++] = plen; /* Password length */
if (plen > 0)
memcpy (msg + len, priv->password, plen); /* Password */
len += plen;
nice_socket_send_reliable (priv->base_socket, NULL, len, msg);
priv->state = SOCKS_STATE_AUTH;
} else {
/* Authentication required but no auth info available */
goto error;
}
} else if (data[1] == 0x00) {
goto send_connect;
} else {
/* method not supported by socks server */
goto error;
}
} else {
/* invalid SOCKS server version */
goto error;
}
} else {
/* read error */
goto error;
}
}
break;
case SOCKS_STATE_AUTH:
{
guint8 data[2];
GInputVector local_recv_buf = { data, sizeof (data) };
NiceInputMessage local_recv_message = { &local_recv_buf, 1, NULL, 0 };
nice_debug ("Socks5 state auth");
if (priv->base_socket) {
ret = nice_socket_recv_messages (priv->base_socket,
&local_recv_message, 1);
}
if (ret <= 0) {
return ret;
} else if (ret == 1 && local_recv_buf.size == sizeof(data)) {
if (data[0] == 0x01 && data[1] == 0x00) {
/* Authenticated */
goto send_connect;
} else {
/* Authentication failed */
goto error;
}
}
}
break;
case SOCKS_STATE_CONNECT:
{
guint8 data[22];
GInputVector local_recv_buf = { data, sizeof (data) };
NiceInputMessage local_recv_message = { &local_recv_buf, 1, NULL, 0 };
nice_debug ("Socks5 state connect");
if (priv->base_socket) {
local_recv_buf.size = 4;
ret = nice_socket_recv_messages (priv->base_socket,
&local_recv_message, 1);
}
if (ret <= 0) {
return ret;
} else if (ret == 1 && local_recv_buf.size == 4) {
if (data[0] == 0x05) {
switch (data[1]) {
case 0x00:
if (data[2] == 0x00) {
switch (data[3]) {
case 0x01: /* IPV4 bound address */
local_recv_buf.size = 6;
ret = nice_socket_recv_messages (priv->base_socket,
&local_recv_message, 1);
if (ret != 1 || local_recv_buf.size != 6) {
/* Could not read server bound address */
goto error;
}
break;
case 0x04: /* IPV6 bound address */
local_recv_buf.size = 18;
ret = nice_socket_recv_messages (priv->base_socket,
&local_recv_message, 1);
if (ret != 1 || local_recv_buf.size != 18) {
/* Could not read server bound address */
goto error;
}
break;
default:
/* Unsupported address type */
goto error;
}
nice_socket_flush_send_queue (priv->base_socket,
&priv->send_queue);
priv->state = SOCKS_STATE_CONNECTED;
} else {
/* Wrong reserved value */
goto error;
}
break;
case 0x01: /* general SOCKS server failure */
case 0x02: /* connection not allowed by ruleset */
case 0x03: /* Network unreachable */
case 0x04: /* Host unreachable */
case 0x05: /* Connection refused */
case 0x06: /* TTL expired */
case 0x07: /* Command not supported */
case 0x08: /* Address type not supported */
default: /* Unknown error */
goto error;
break;
}
} else {
/* Wrong server version */
goto error;
}
} else {
/* Invalid data received */
goto error;
}
}
break;
case SOCKS_STATE_ERROR:
default:
/* Unknown status */
goto error;
}
return 0;
send_connect:
{
gchar msg[22];
gint len = 0;
union {
struct sockaddr_storage storage;
struct sockaddr addr;
struct sockaddr_in in;
struct sockaddr_in6 in6;
} name;
nice_address_copy_to_sockaddr(&priv->addr, &name.addr);
msg[len++] = 0x05; /* SOCKS version */
msg[len++] = 0x01; /* connect command */
msg[len++] = 0x00; /* reserved */
if (name.storage.ss_family == AF_INET) {
msg[len++] = 0x01; /* IPV4 address type */
/* Address */
memcpy (msg + len, &(&name.in)->sin_addr, 4);
len += 4;
/* Port */
memcpy (msg + len, &(&name.in)->sin_port, 2);
len += 2;
} else if (name.storage.ss_family == AF_INET6) {
msg[len++] = 0x04; /* IPV6 address type */
/* Address */
memcpy (msg + len, &(&name.in6)->sin6_addr, 16);
len += 16;
/* Port */
memcpy (msg + len, &(&name.in6)->sin6_port, 2);
len += 2;
}
nice_socket_send_reliable (priv->base_socket, NULL, len, msg);
priv->state = SOCKS_STATE_CONNECT;
return 0;
}
error:
nice_debug ("Socks5 error");
if (priv->base_socket)
nice_socket_free (priv->base_socket);
priv->base_socket = NULL;
priv->state = SOCKS_STATE_ERROR;
return -1;
}
static gint
socket_send_messages (NiceSocket *sock, const NiceAddress *to,
const NiceOutputMessage *messages, guint n_messages)
{
Socks5Priv *priv = sock->priv;
/* Make sure socket has not been freed: */
g_assert (sock->priv != NULL);
if (priv->state == SOCKS_STATE_CONNECTED) {
/* Fast path: pass through to the base socket once connected. */
if (priv->base_socket == NULL)
return -1;
return nice_socket_send_messages (priv->base_socket, to, messages,
n_messages);
} else if (priv->state == SOCKS_STATE_ERROR) {
return -1;
} else {
return 0;
}
}
static gint
socket_send_messages_reliable (NiceSocket *sock, const NiceAddress *to,
const NiceOutputMessage *messages, guint n_messages)
{
Socks5Priv *priv = sock->priv;
if (priv->state == SOCKS_STATE_CONNECTED) {
/* Fast path: pass through to the base socket once connected. */
if (priv->base_socket == NULL)
return -1;
return nice_socket_send_messages_reliable (priv->base_socket, to, messages,
n_messages);
} else if (priv->state == SOCKS_STATE_ERROR) {
return -1;
} else {
nice_socket_queue_send (&priv->send_queue, to, messages, n_messages);
}
return n_messages;
}
static gboolean
socket_is_reliable (NiceSocket *sock)
{
Socks5Priv *priv = sock->priv;
return nice_socket_is_reliable (priv->base_socket);
}
static gboolean
socket_can_send (NiceSocket *sock, NiceAddress *addr)
{
Socks5Priv *priv = sock->priv;
return nice_socket_can_send (priv->base_socket, addr);
}
static void
socket_set_writable_callback (NiceSocket *sock,
NiceSocketWritableCb callback, gpointer user_data)
{
Socks5Priv *priv = sock->priv;
nice_socket_set_writable_callback (priv->base_socket, callback, user_data);
}
static gboolean
socket_is_based_on (NiceSocket *sock, NiceSocket *other)
{
Socks5Priv *priv = sock->priv;
return (sock == other) ||
(priv && nice_socket_is_based_on (priv->base_socket, other));
}