summaryrefslogtreecommitdiff
path: root/indra/llmessage/llproxy.cpp
blob: 537efa69d88bb1bdaf33b31fb0f0a814f7a18ca3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
/**
 * @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;

// 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(NULL),
		mUDPProxy(),
		mTCPProxy(),
		mHTTPProxy(),
		mProxyType(LLPROXY_SOCKS),
		mAuthMethodSelected(METHOD_NOAUTH),
		mSocksUsername(),
		mSocksPassword()
{}

LLProxy::~LLProxy()
{
	if (ll_apr_is_initialized())
	{
		stopSOCKSProxy();
		disableHTTPProxy();
	}
}

/**
 * @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 = socks_username.size() + socks_password.size() + 3;
		char * password_auth = new char[request_size];
		password_auth[0] = 0x01;
		password_auth[1] = socks_username.size();
		memcpy(&password_auth[2], socks_username.c_str(), socks_username.size());
		password_auth[socks_username.size() + 2] = 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()
{
	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 (mHTTPProxyEnabled)
	{
		// We think we should proxy, lock the proxy mutex.
		LLMutexLock lock(&mProxyMutex);
		// Now test again to verify that the proxy wasn't disabled between the first check and the lock.
		if (mHTTPProxyEnabled)
		{
            LLCore::LLHttp::check_curl_code(curl_easy_setopt(handle, CURLOPT_PROXY, mHTTPProxy.getIPString().c_str()), CURLOPT_PROXY);
            LLCore::LLHttp::check_curl_code(curl_easy_setopt(handle, CURLOPT_PROXYPORT, mHTTPProxy.getPort()), CURLOPT_PROXYPORT);

			if (mProxyType == LLPROXY_SOCKS)
			{
                LLCore::LLHttp::check_curl_code(curl_easy_setopt(handle, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5), CURLOPT_PROXYTYPE);
				if (mAuthMethodSelected == METHOD_PASSWORD)
				{
					std::string auth_string = mSocksUsername + ":" + 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 1000ms 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(1000);

  	rv = apr_socket_send(apr_socket, dataout, &outlen);
	if (APR_SUCCESS != rv)
	{
		LL_WARNS("Proxy") << "Error sending data to proxy control channel, status: " << rv << 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)
		{
			LL_WARNS("Proxy") << "Error receiving data from proxy control channel, status: " << rv << 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();
}