/** * @file llproxy.h * @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 * $/LicenseInfo$ */ #ifndef LL_PROXY_H #define LL_PROXY_H #include "llhost.h" #include "lliosocket.h" #include "llmemory.h" #include "llsingleton.h" #include "llthread.h" #include "llmutex.h" #include #include // SOCKS error codes returned from the StartProxy method #define SOCKS_OK 0 #define SOCKS_CONNECT_ERROR (-1) #define SOCKS_NOT_PERMITTED (-2) #define SOCKS_NOT_ACCEPTABLE (-3) #define SOCKS_AUTH_FAIL (-4) #define SOCKS_UDP_FWD_NOT_GRANTED (-5) #define SOCKS_HOST_CONNECT_FAILED (-6) #define SOCKS_INVALID_HOST (-7) #ifndef MAXHOSTNAMELEN #define MAXHOSTNAMELEN (255 + 1) /* socks5: 255, +1 for len. */ #endif #define SOCKSMAXUSERNAMELEN 255 #define SOCKSMAXPASSWORDLEN 255 #define SOCKSMINUSERNAMELEN 1 #define SOCKSMINPASSWORDLEN 1 #define SOCKS_VERSION 0x05 // we are using SOCKS 5 #define SOCKS_HEADER_SIZE 10 // SOCKS 5 address/hostname types #define ADDRESS_IPV4 0x01 #define ADDRESS_HOSTNAME 0x03 #define ADDRESS_IPV6 0x04 // Lets just use our own ipv4 struct rather than dragging in system // specific headers union ipv4_address_t { U8 octets[4]; U32 addr32; }; // SOCKS 5 control channel commands #define COMMAND_TCP_STREAM 0x01 #define COMMAND_TCP_BIND 0x02 #define COMMAND_UDP_ASSOCIATE 0x03 // SOCKS 5 command replies #define REPLY_REQUEST_GRANTED 0x00 #define REPLY_GENERAL_FAIL 0x01 #define REPLY_RULESET_FAIL 0x02 #define REPLY_NETWORK_UNREACHABLE 0x03 #define REPLY_HOST_UNREACHABLE 0x04 #define REPLY_CONNECTION_REFUSED 0x05 #define REPLY_TTL_EXPIRED 0x06 #define REPLY_PROTOCOL_ERROR 0x07 #define REPLY_TYPE_NOT_SUPPORTED 0x08 #define FIELD_RESERVED 0x00 // The standard SOCKS 5 request packet // Push current alignment to stack and set alignment to 1 byte boundary // This enabled us to use structs directly to set up and receive network packets // into the correct fields, without fear of boundary alignment causing issues #pragma pack(push,1) // SOCKS 5 command packet struct socks_command_request_t { U8 version; U8 command; U8 reserved; U8 atype; U32 address; U16 port; }; // Standard SOCKS 5 reply packet struct socks_command_response_t { U8 version; U8 reply; U8 reserved; U8 atype; U8 add_bytes[4]; U16 port; }; #define AUTH_NOT_ACCEPTABLE 0xFF // reply if preferred methods are not available #define AUTH_SUCCESS 0x00 // reply if authentication successful // SOCKS 5 authentication request, stating which methods the client supports struct socks_auth_request_t { U8 version; U8 num_methods; U8 methods; // We are only using a single method currently }; // SOCKS 5 authentication response packet, stating server preferred method struct socks_auth_response_t { U8 version; U8 method; }; // SOCKS 5 password reply packet struct authmethod_password_reply_t { U8 version; U8 status; }; // SOCKS 5 UDP packet header struct proxywrap_t { U16 rsv; U8 frag; U8 atype; U32 addr; U16 port; }; #pragma pack(pop) /* restore original alignment from stack */ // Currently selected HTTP proxy type enum LLHttpProxyType { LLPROXY_SOCKS = 0, LLPROXY_HTTP = 1 }; // Auth types enum LLSocks5AuthType { METHOD_NOAUTH = 0x00, // Client supports no auth METHOD_GSSAPI = 0x01, // Client supports GSSAPI (Not currently supported) METHOD_PASSWORD = 0x02 // Client supports username/password }; /** * @brief Manage SOCKS 5 UDP proxy and HTTP proxy. * * This class is responsible for managing two interconnected tasks, * connecting to a SOCKS 5 proxy for use by LLPacketRing to send UDP * packets and managing proxy settings for HTTP requests. * *

Threading:

* Because HTTP requests can be generated in threads outside the * main thread, it is necessary for some of the information stored * by this class to be available to other threads. The members that * need to be read across threads are in a labeled section below. * To protect those members, a mutex, mProxyMutex should be locked * before reading or writing those members. Methods that can lock * mProxyMutex are in a labeled section below. Those methods should * not be called while the mutex is already locked. * * There is also a LLAtomic type flag (mHTTPProxyEnabled) that is used * to track whether the HTTP proxy is currently enabled. This allows * for faster unlocked checks to see if the proxy is enabled. This * allows us to cut down on the performance hit when the proxy is * disabled compared to before this class was introduced. * *

UDP Proxying:

* UDP datagrams are proxied via a SOCKS 5 proxy with the UDP associate * command. To initiate the proxy, a TCP socket connection is opened * to the SOCKS 5 host, and after a handshake exchange, the server * returns a port and address to send the UDP traffic that is to be * proxied to. The LLProxy class tracks this address and port after the * exchange and provides it to LLPacketRing when required to. All UDP * proxy management occurs in the main thread. * *

HTTP Proxying:

* This class allows all viewer HTTP packets to be sent through a proxy. * The user can select whether to send HTTP packets through a standard * "web" HTTP proxy, through a SOCKS 5 proxy, or to not proxy HTTP * communication. This class does not manage the integrated web browser * proxy, which is handled in llviewermedia.cpp. * * The implementation of HTTP proxying is handled by libcurl. LLProxy * is responsible for managing the HTTP proxy options and provides a * thread-safe method to apply those options to a curl request * (LLProxy::applyProxySettings()). This method is overloaded * to accommodate the various abstraction libcurl layers that exist * throughout the viewer (CURL). * * To ensure thread safety, all LLProxy members that relate to the HTTP * proxy require the LLProxyMutex to be locked before accessing. * * *TODO$: This should be moved into the LLCore::Http space. * */ class LLProxy: public LLSingleton { /*########################################################################################### METHODS THAT DO NOT LOCK mProxyMutex! ###########################################################################################*/ // Constructor, cannot have parameters due to LLSingleton parent class. Call from main thread only. LLSINGLETON(LLProxy); LOG_CLASS(LLProxy); /*virtual*/ void initSingleton(); public: // Static check for enabled status for UDP packets. Call from main thread only. static bool isSOCKSProxyEnabled() { return sUDPProxyEnabled; } // Get the UDP proxy address and port. Call from main thread only. LLHost getUDPProxy() const { return mUDPProxy; } /*########################################################################################### END OF NON-LOCKING METHODS ###########################################################################################*/ /*########################################################################################### METHODS THAT LOCK mProxyMutex! DO NOT CALL WHILE mProxyMutex IS LOCKED! ###########################################################################################*/ private: // Destructor, closes open connections. Do not call directly, use cleanupClass(). ~LLProxy(); public: // Delete LLProxy singleton. Allows the apr_socket used in the SOCKS 5 control channel to be // destroyed before the call to apr_terminate. Call from main thread only. static void cleanupClass(); // Apply the current proxy settings to a curl request. Doesn't do anything if mHTTPProxyEnabled is false. // Safe to call from any thread. static void applyProxySettings(CURL* handle); // Start a connection to the SOCKS 5 proxy. Call from main thread only. S32 startSOCKSProxy(LLHost host); // Disconnect and clean up any connection to the SOCKS 5 proxy. Call from main thread only. void stopSOCKSProxy(); // Use Password auth when connecting to the SOCKS proxy. Call from main thread only. bool setAuthPassword(const std::string &username, const std::string &password); // Disable authentication when connecting to the SOCKS proxy. Call from main thread only. void setAuthNone(); // Proxy HTTP packets via httpHost, which can be a SOCKS 5 or a HTTP proxy. // as specified in type. Call from main thread only. bool enableHTTPProxy(LLHost httpHost, LLHttpProxyType type); bool enableHTTPProxy(); // Stop proxying HTTP packets. Call from main thread only. void disableHTTPProxy(); /*########################################################################################### END OF LOCKING METHODS ###########################################################################################*/ private: /*########################################################################################### METHODS THAT LOCK mProxyMutex! DO NOT CALL WHILE mProxyMutex IS LOCKED! ###########################################################################################*/ // Perform a SOCKS 5 authentication and UDP association with the proxy server. S32 proxyHandshake(LLHost proxy); // Get the currently selected auth method. LLSocks5AuthType getSelectedAuthMethod() const; // Get the currently selected HTTP proxy type LLHttpProxyType getHTTPProxyType() const; std::string getSocksPwd() const; std::string getSocksUser() const; /*########################################################################################### END OF LOCKING METHODS ###########################################################################################*/ private: // Is the HTTP proxy enabled? Safe to read in any thread, but do not write directly. // Instead use enableHTTPProxy() and disableHTTPProxy() instead. mutable LLAtomicBool mHTTPProxyEnabled; // Mutex to protect shared members in non-main thread calls to applyProxySettings(). mutable LLMutex mProxyMutex; /*########################################################################################### MEMBERS READ AND WRITTEN ONLY IN THE MAIN THREAD. DO NOT SHARE! ###########################################################################################*/ // Is the UDP proxy enabled? static bool sUDPProxyEnabled; // UDP proxy address and port LLHost mUDPProxy; // TCP proxy control channel address and port LLHost mTCPProxy; // socket handle to proxy TCP control channel LLSocket::ptr_t mProxyControlChannel; /*########################################################################################### END OF UNSHARED MEMBERS ###########################################################################################*/ /*########################################################################################### MEMBERS WRITTEN IN MAIN THREAD AND READ IN ANY THREAD. ONLY READ OR WRITE AFTER LOCKING mProxyMutex! ###########################################################################################*/ // HTTP proxy address and port LLHost mHTTPProxy; // Currently selected HTTP proxy type. Can be web or socks. LLHttpProxyType mProxyType; // SOCKS 5 selected authentication method. LLSocks5AuthType mAuthMethodSelected; // SOCKS 5 username std::string mSocksUsername; // SOCKS 5 password std::string mSocksPassword; /*########################################################################################### END OF SHARED MEMBERS ###########################################################################################*/ // A hack to get arround getInstance() and capture_dependency() which are unsafe to use inside threads // set/reset on init/cleanup, strictly for use in applyProxySettings static LLProxy* sProxyInstance; }; #endif