/**
* @file llproxy.cpp
* @brief UDP and HTTP proxy communications
*
* $LicenseInfo:firstyear=2011&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2011, Linden Research, Inc.
*
* 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;
* version 2.1 of the License only.
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#include "linden_common.h"
#include "llproxy.h"
#include <string>
#include <curl/curl.h>
#include "httpcommon.h"
#include "llapr.h"
#include "llhost.h"
// Static class variable instances
// We want this to be static to avoid excessive indirection on every
// incoming packet just to do a simple bool test. The getter for this
// member is also static
bool LLProxy::sUDPProxyEnabled = false;
LLProxy* LLProxy::sProxyInstance = NULL;
// Some helpful TCP static functions.
static apr_status_t tcp_blocking_handshake(LLSocket::ptr_t handle, char * dataout, apr_size_t outlen, char * datain, apr_size_t maxinlen); // Do a TCP data handshake
static LLSocket::ptr_t tcp_open_channel(LLHost host); // Open a TCP channel to a given host
static void tcp_close_channel(LLSocket::ptr_t* handle_ptr); // Close an open TCP channel
LLProxy::LLProxy():
mHTTPProxyEnabled(false),
mProxyMutex(),
mUDPProxy(),
mTCPProxy(),
mHTTPProxy(),
mProxyType(LLPROXY_SOCKS),
mAuthMethodSelected(METHOD_NOAUTH),
mSocksUsername(),
mSocksPassword()
{}
LLProxy::~LLProxy()
{
if (ll_apr_is_initialized())
{
// locks mutex
stopSOCKSProxy();
disableHTTPProxy();
}
// The primary safety of sProxyInstance is the fact that by the
// point SUBSYSTEM_CLEANUP(LLProxy) gets called, nothing should
// be capable of using proxy
sProxyInstance = NULL;
}
void LLProxy::initSingleton()
{
sProxyInstance = this;
}
/**
* @brief Open the SOCKS 5 TCP control channel.
*
* Perform a SOCKS 5 authentication and UDP association with the proxy server.
*
* @param proxy The SOCKS 5 server to connect to.
* @return SOCKS_OK if successful, otherwise a socks error code from llproxy.h.
*/
S32 LLProxy::proxyHandshake(LLHost proxy)
{
S32 result;
/* SOCKS 5 Auth request */
socks_auth_request_t socks_auth_request;
socks_auth_response_t socks_auth_response;
socks_auth_request.version = SOCKS_VERSION; // SOCKS version 5
socks_auth_request.num_methods = 1; // Sending 1 method.
socks_auth_request.methods = getSelectedAuthMethod(); // Send only the selected method.
result = tcp_blocking_handshake(mProxyControlChannel,
static_cast<char*>(static_cast<void*>(&socks_auth_request)),
sizeof(socks_auth_request),
static_cast<char*>(static_cast<void*>(&socks_auth_response)),
sizeof(socks_auth_response));
if (result != APR_SUCCESS)
{
LL_WARNS("Proxy") << "SOCKS authentication request failed, error on TCP control channel : " << result << LL_ENDL;
stopSOCKSProxy();
return SOCKS_CONNECT_ERROR;
}
if (socks_auth_response.method == AUTH_NOT_ACCEPTABLE)
{
LL_WARNS("Proxy") << "SOCKS 5 server refused all our authentication methods." << LL_ENDL;
stopSOCKSProxy();
return SOCKS_NOT_ACCEPTABLE;
}
/* SOCKS 5 USERNAME/PASSWORD authentication */
if (socks_auth_response.method == METHOD_PASSWORD)
{
// The server has requested a username/password combination
std::string socks_username(getSocksUser());
std::string socks_password(getSocksPwd());
U32 request_size = static_cast<S32>(socks_username.size() + socks_password.size() + 3);
char * password_auth = new char[request_size];
password_auth[0] = 0x01;
password_auth[1] = (char)(socks_username.size());
memcpy(&password_auth[2], socks_username.c_str(), socks_username.size());
password_auth[socks_username.size() + 2] = (char)(socks_password.size());
memcpy(&password_auth[socks_username.size() + 3], socks_password.c_str(), socks_password.size());
authmethod_password_reply_t password_reply;
result = tcp_blocking_handshake(mProxyControlChannel,
password_auth,
request_size,
static_cast<char*>(static_cast<void*>(&password_reply)),
sizeof(password_reply));
delete[] password_auth;
if (result != APR_SUCCESS)
{
LL_WARNS("Proxy") << "SOCKS authentication failed, error on TCP control channel : " << result << LL_ENDL;
stopSOCKSProxy();
return SOCKS_CONNECT_ERROR;
}
if (password_reply.status != AUTH_SUCCESS)
{
LL_WARNS("Proxy") << "SOCKS authentication failed" << LL_ENDL;
stopSOCKSProxy();
return SOCKS_AUTH_FAIL;
}
}
/* SOCKS5 connect request */
socks_command_request_t connect_request;
socks_command_response_t connect_reply;
connect_request.version = SOCKS_VERSION; // SOCKS V5
connect_request.command = COMMAND_UDP_ASSOCIATE; // Associate UDP
connect_request.reserved = FIELD_RESERVED;
connect_request.atype = ADDRESS_IPV4;
connect_request.address = htonl(0); // 0.0.0.0
connect_request.port = htons(0); // 0
// "If the client is not in possession of the information at the time of the UDP ASSOCIATE,
// the client MUST use a port number and address of all zeros. RFC 1928"
result = tcp_blocking_handshake(mProxyControlChannel,
static_cast<char*>(static_cast<void*>(&connect_request)),
sizeof(connect_request),
static_cast<char*>(static_cast<void*>(&connect_reply)),
sizeof(connect_reply));
if (result != APR_SUCCESS)
{
LL_WARNS("Proxy") << "SOCKS connect request failed, error on TCP control channel : " << result << LL_ENDL;
stopSOCKSProxy();
return SOCKS_CONNECT_ERROR;
}
if (connect_reply.reply != REPLY_REQUEST_GRANTED)
{
LL_WARNS("Proxy") << "Connection to SOCKS 5 server failed, UDP forward request not granted" << LL_ENDL;
stopSOCKSProxy();
return SOCKS_UDP_FWD_NOT_GRANTED;
}
mUDPProxy.setPort(ntohs(connect_reply.port)); // reply port is in network byte order
mUDPProxy.setAddress(proxy.getAddress());
// The connection was successful. We now have the UDP port to send requests that need forwarding to.
LL_INFOS("Proxy") << "SOCKS 5 UDP proxy connected on " << mUDPProxy << LL_ENDL;
return SOCKS_OK;
}
/**
* @brief Initiates a SOCKS 5 proxy session.
*
* Performs basic checks on host to verify that it is a valid address. Opens the control channel
* and then negotiates the proxy connection with the server. Closes any existing SOCKS
* connection before proceeding. Also disables an HTTP proxy if it is using SOCKS as the proxy.
*
*
* @param host Socks server to connect to.
* @return SOCKS_OK if successful, otherwise a SOCKS error code defined in llproxy.h.
*/
S32 LLProxy::startSOCKSProxy(LLHost host)
{
if (host.isOk())
{
mTCPProxy = host;
}
else
{
return SOCKS_INVALID_HOST;
}
// Close any running SOCKS connection.
stopSOCKSProxy();
mProxyControlChannel = tcp_open_channel(mTCPProxy);
if (!mProxyControlChannel)
{
return SOCKS_HOST_CONNECT_FAILED;
}
S32 status = proxyHandshake(mTCPProxy);
if (status != SOCKS_OK)
{
// Shut down the proxy if any of the above steps failed.
stopSOCKSProxy();
}
else
{
// Connection was successful.
sUDPProxyEnabled = true;
}
return status;
}
/**
* @brief Stop using the SOCKS 5 proxy.
*
* This will stop sending UDP packets through the SOCKS 5 proxy
* and will also stop the HTTP proxy if it is configured to use SOCKS.
* The proxy control channel will also be disconnected.
*/
void LLProxy::stopSOCKSProxy()
{
sUDPProxyEnabled = false;
// If the SOCKS proxy is requested to stop and we are using that for HTTP as well
// then we must shut down any HTTP proxy operations. But it is allowable if web
// proxy is being used to continue proxying HTTP.
if (LLPROXY_SOCKS == getHTTPProxyType())
{
disableHTTPProxy();
}
if (mProxyControlChannel)
{
tcp_close_channel(&mProxyControlChannel);
}
}
/**
* @brief Set the proxy's SOCKS authentication method to none.
*/
void LLProxy::setAuthNone()
{
LLMutexLock lock(&mProxyMutex);
mAuthMethodSelected = METHOD_NOAUTH;
}
/**
* @brief Set the proxy's SOCKS authentication method to password.
*
* Check whether the lengths of the supplied username
* and password conform to the lengths allowed by the
* SOCKS protocol.
*
* @param username The SOCKS username to send.
* @param password The SOCKS password to send.
* @return Return true if applying the settings was successful. No changes are made if false.
*
*/
bool LLProxy::setAuthPassword(const std::string &username, const std::string &password)
{
if (username.length() > SOCKSMAXUSERNAMELEN || password.length() > SOCKSMAXPASSWORDLEN ||
username.length() < SOCKSMINUSERNAMELEN || password.length() < SOCKSMINPASSWORDLEN)
{
LL_WARNS("Proxy") << "Invalid SOCKS 5 password or username length." << LL_ENDL;
return false;
}
LLMutexLock lock(&mProxyMutex);
mAuthMethodSelected = METHOD_PASSWORD;
mSocksUsername = username;
mSocksPassword = password;
return true;
}
/**
* @brief Enable the HTTP proxy for either SOCKS or HTTP.
*
* Check the supplied host to see if it is a valid IP and port.
*
* @param httpHost Proxy server to connect to.
* @param type Is the host a SOCKS or HTTP proxy.
* @return Return true if applying the setting was successful. No changes are made if false.
*/
bool LLProxy::enableHTTPProxy(LLHost httpHost, LLHttpProxyType type)
{
if (!httpHost.isOk())
{
LL_WARNS("Proxy") << "Invalid SOCKS 5 Server" << LL_ENDL;
return false;
}
LLMutexLock lock(&mProxyMutex);
mHTTPProxy = httpHost;
mProxyType = type;
mHTTPProxyEnabled = true;
return true;
}
/**
* @brief Enable the HTTP proxy without changing the proxy settings.
*
* This should not be called unless the proxy has already been set up.
*
* @return Return true only if the current settings are valid and the proxy was enabled.
*/
bool LLProxy::enableHTTPProxy()
{
bool ok;
LLMutexLock lock(&mProxyMutex);
ok = (mHTTPProxy.isOk());
if (ok)
{
mHTTPProxyEnabled = true;
}
return ok;
}
/**
* @brief Disable the HTTP proxy.
*/
void LLProxy::disableHTTPProxy()
{
LLMutexLock lock(&mProxyMutex);
mHTTPProxyEnabled = false;
}
/**
* @brief Get the currently selected HTTP proxy type
*/
LLHttpProxyType LLProxy::getHTTPProxyType() const
{
LLMutexLock lock(&mProxyMutex);
return mProxyType;
}
/**
* @brief Get the SOCKS 5 password.
*/
std::string LLProxy::getSocksPwd() const
{
LLMutexLock lock(&mProxyMutex);
return mSocksPassword;
}
/**
* @brief Get the SOCKS 5 username.
*/
std::string LLProxy::getSocksUser() const
{
LLMutexLock lock(&mProxyMutex);
return mSocksUsername;
}
/**
* @brief Get the currently selected SOCKS 5 authentication method.
*
* @return Returns either none or password.
*/
LLSocks5AuthType LLProxy::getSelectedAuthMethod() const
{
LLMutexLock lock(&mProxyMutex);
return mAuthMethodSelected;
}
/**
* @brief Stop the LLProxy and make certain that any APR pools and classes are deleted before terminating APR.
*
* Deletes the LLProxy singleton, destroying the APR pool used by the control channel as well as .
*/
//static
void LLProxy::cleanupClass()
{
if (instanceExists())
{
getInstance()->stopSOCKSProxy();
deleteSingleton();
}
}
/**
* @brief Apply proxy settings to a CuRL request if an HTTP proxy is enabled.
*
* This method has been designed to be safe to call from
* any thread in the viewer. This allows requests in the
* texture fetch thread to be aware of the proxy settings.
* When the HTTP proxy is enabled, the proxy mutex will
* be locked every time this method is called.
*
* @param handle A pointer to a valid CURL request, before it has been performed.
*/
void LLProxy::applyProxySettings(CURL* handle)
{
// Do a faster unlocked check to see if we are supposed to proxy.
if (sProxyInstance && sProxyInstance->mHTTPProxyEnabled)
{
// We think we should proxy, lock the proxy mutex. sProxyInstance is not protected by mutex
LLMutexLock lock(&sProxyInstance->mProxyMutex);
// Now test again to verify that the proxy wasn't disabled between the first check and the lock.
if (sProxyInstance->mHTTPProxyEnabled)
{
LLCore::LLHttp::check_curl_code(curl_easy_setopt(handle, CURLOPT_PROXY, sProxyInstance->mHTTPProxy.getIPString().c_str()), CURLOPT_PROXY);
LLCore::LLHttp::check_curl_code(curl_easy_setopt(handle, CURLOPT_PROXYPORT, sProxyInstance->mHTTPProxy.getPort()), CURLOPT_PROXYPORT);
if (sProxyInstance->mProxyType == LLPROXY_SOCKS)
{
LLCore::LLHttp::check_curl_code(curl_easy_setopt(handle, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5), CURLOPT_PROXYTYPE);
if (sProxyInstance->mAuthMethodSelected == METHOD_PASSWORD)
{
std::string auth_string = sProxyInstance->mSocksUsername + ":" + sProxyInstance->mSocksPassword;
LLCore::LLHttp::check_curl_code(curl_easy_setopt(handle, CURLOPT_PROXYUSERPWD, auth_string.c_str()), CURLOPT_PROXYUSERPWD);
}
}
else
{
LLCore::LLHttp::check_curl_code(curl_easy_setopt(handle, CURLOPT_PROXYTYPE, CURLPROXY_HTTP), CURLOPT_PROXYTYPE);
}
}
}
}
/**
* @brief Send one TCP packet and receive one in return.
*
* This operation is done synchronously with a 100ms timeout. Therefore, it should not be used when a blocking
* operation would impact the operation of the viewer.
*
* @param handle_ptr Pointer to a connected LLSocket of type STREAM_TCP.
* @param dataout Data to send.
* @param outlen Length of dataout.
* @param datain Buffer for received data. Undefined if return value is not APR_SUCCESS.
* @param maxinlen Maximum possible length of received data. Short reads are allowed.
* @return Indicates APR status code of exchange. APR_SUCCESS if exchange was successful, -1 if invalid data length was received.
*/
static apr_status_t tcp_blocking_handshake(LLSocket::ptr_t handle, char * dataout, apr_size_t outlen, char * datain, apr_size_t maxinlen)
{
apr_socket_t* apr_socket = handle->getSocket();
apr_status_t rv = APR_SUCCESS;
apr_size_t expected_len = outlen;
handle->setBlocking(100000); // 100ms, 100000us. Should be sufficient for localhost, nearby network
rv = apr_socket_send(apr_socket, dataout, &outlen);
if (APR_SUCCESS != rv)
{
char buf[MAX_STRING];
LL_WARNS("Proxy") << "Error sending data to proxy control channel, status: " << rv << " " << apr_strerror(rv, buf, MAX_STRING) << LL_ENDL;
ll_apr_warn_status(rv);
}
else if (expected_len != outlen)
{
LL_WARNS("Proxy") << "Incorrect data length sent. Expected: " << expected_len <<
" Sent: " << outlen << LL_ENDL;
rv = -1;
}
if (APR_SUCCESS == rv)
{
expected_len = maxinlen;
rv = apr_socket_recv(apr_socket, datain, &maxinlen);
if (rv != APR_SUCCESS)
{
char buf[MAX_STRING];
LL_WARNS("Proxy") << "Error receiving data from proxy control channel, status: " << rv << " " << apr_strerror(rv, buf, MAX_STRING) << LL_ENDL;
ll_apr_warn_status(rv);
}
else if (expected_len < maxinlen)
{
LL_WARNS("Proxy") << "Incorrect data length received. Expected: " << expected_len <<
" Received: " << maxinlen << LL_ENDL;
rv = -1;
}
}
handle->setNonBlocking();
return rv;
}
/**
* @brief Open a LLSocket and do a blocking connect to the chosen host.
*
* Checks for a successful connection, and makes sure the connection is closed if it fails.
*
* @param host The host to open the connection to.
* @return The created socket. Will evaluate as NULL if the connection is unsuccessful.
*/
static LLSocket::ptr_t tcp_open_channel(LLHost host)
{
LLSocket::ptr_t socket = LLSocket::create(NULL, LLSocket::STREAM_TCP);
bool connected = socket->blockingConnect(host);
if (!connected)
{
tcp_close_channel(&socket);
}
return socket;
}
/**
* @brief Close the socket.
*
* @param handle_ptr The handle of the socket being closed. A pointer-to-pointer to avoid increasing the use count.
*/
static void tcp_close_channel(LLSocket::ptr_t* handle_ptr)
{
LL_DEBUGS("Proxy") << "Resetting proxy LLSocket handle, use_count == " << handle_ptr->use_count() << LL_ENDL;
handle_ptr->reset();
}