/* * Copyright (c) 2013-2016, The PurpleI2P Project * * This file is part of Purple i2pd project and licensed under BSD3 * * See full license text in LICENSE file at top of project tree */ #include #include #include #include "I2PEndian.h" #include "Log.h" #include "Timestamp.h" #include "LeaseSet.h" #include "ClientContext.h" #include "Transports.h" #include "Signature.h" #include "I2CP.h" namespace i2p { namespace client { I2CPDestination::I2CPDestination (std::shared_ptr owner, std::shared_ptr identity, bool isPublic, const std::map& params): LeaseSetDestination (isPublic, ¶ms), m_Owner (owner), m_Identity (identity) { } void I2CPDestination::SetEncryptionPrivateKey (const uint8_t * key) { memcpy (m_EncryptionPrivateKey, key, 256); } void I2CPDestination::HandleDataMessage (const uint8_t * buf, size_t len) { uint32_t length = bufbe32toh (buf); if (length > len - 4) length = len - 4; m_Owner->SendMessagePayloadMessage (buf + 4, length); } void I2CPDestination::CreateNewLeaseSet (std::vector > tunnels) { i2p::data::LocalLeaseSet ls (m_Identity, m_EncryptionPrivateKey, tunnels); // we don't care about encryption key m_LeaseSetExpirationTime = ls.GetExpirationTime (); uint8_t * leases = ls.GetLeases (); leases[-1] = tunnels.size (); htobe16buf (leases - 3, m_Owner->GetSessionID ()); size_t l = 2/*sessionID*/ + 1/*num leases*/ + i2p::data::LEASE_SIZE*tunnels.size (); m_Owner->SendI2CPMessage (I2CP_REQUEST_VARIABLE_LEASESET_MESSAGE, leases - 3, l); } void I2CPDestination::LeaseSetCreated (const uint8_t * buf, size_t len) { auto ls = new i2p::data::LocalLeaseSet (m_Identity, buf, len); ls->SetExpirationTime (m_LeaseSetExpirationTime); SetLeaseSet (ls); } void I2CPDestination::SendMsgTo (const uint8_t * payload, size_t len, const i2p::data::IdentHash& ident, uint32_t nonce) { auto msg = NewI2NPMessage (); uint8_t * buf = msg->GetPayload (); htobe32buf (buf, len); memcpy (buf + 4, payload, len); msg->len += len + 4; msg->FillI2NPMessageHeader (eI2NPData); auto remote = FindLeaseSet (ident); if (remote) GetService ().post (std::bind (&I2CPDestination::SendMsg, GetSharedFromThis (), msg, remote)); else { auto s = GetSharedFromThis (); RequestDestination (ident, [s, msg, nonce](std::shared_ptr ls) { if (ls) { bool sent = s->SendMsg (msg, ls); s->m_Owner->SendMessageStatusMessage (nonce, sent ? eI2CPMessageStatusGuaranteedSuccess : eI2CPMessageStatusGuaranteedFailure); } else s->m_Owner->SendMessageStatusMessage (nonce, eI2CPMessageStatusNoLeaseSet); }); } } bool I2CPDestination::SendMsg (std::shared_ptr msg, std::shared_ptr remote) { auto outboundTunnel = GetTunnelPool ()->GetNextOutboundTunnel (); auto leases = remote->GetNonExpiredLeases (); if (!leases.empty () && outboundTunnel) { std::vector msgs; uint32_t i = rand () % leases.size (); auto garlic = WrapMessage (remote, msg, true); msgs.push_back (i2p::tunnel::TunnelMessageBlock { i2p::tunnel::eDeliveryTypeTunnel, leases[i]->tunnelGateway, leases[i]->tunnelID, garlic }); outboundTunnel->SendTunnelDataMsg (msgs); return true; } else { if (outboundTunnel) LogPrint (eLogWarning, "I2CP: Failed to send message. All leases expired"); else LogPrint (eLogWarning, "I2CP: Failed to send message. No outbound tunnels"); return false; } } I2CPSession::I2CPSession (I2CPServer& owner, std::shared_ptr socket): m_Owner (owner), m_Socket (socket), m_NextMessage (nullptr), m_NextMessageLen (0), m_NextMessageOffset (0), m_MessageID (0), m_IsSendAccepted (true) { RAND_bytes ((uint8_t *)&m_SessionID, 2); } I2CPSession::~I2CPSession () { delete[] m_NextMessage; } void I2CPSession::Start () { ReadProtocolByte (); } void I2CPSession::Stop () { Terminate (); } void I2CPSession::ReadProtocolByte () { if (m_Socket) { auto s = shared_from_this (); m_Socket->async_read_some (boost::asio::buffer (m_Buffer, 1), [s](const boost::system::error_code& ecode, std::size_t bytes_transferred) { if (!ecode && bytes_transferred > 0 && s->m_Buffer[0] == I2CP_PROTOCOL_BYTE) s->Receive (); else s->Terminate (); }); } } void I2CPSession::Receive () { m_Socket->async_read_some (boost::asio::buffer (m_Buffer, I2CP_SESSION_BUFFER_SIZE), std::bind (&I2CPSession::HandleReceived, shared_from_this (), std::placeholders::_1, std::placeholders::_2)); } void I2CPSession::HandleReceived (const boost::system::error_code& ecode, std::size_t bytes_transferred) { if (ecode) Terminate (); else { size_t offset = 0; // from m_Buffer if (m_NextMessage) { if (m_NextMessageOffset + bytes_transferred <= m_NextMessageLen) { memcpy (m_NextMessage + m_NextMessageOffset, m_Buffer, bytes_transferred); m_NextMessageOffset += bytes_transferred; offset = bytes_transferred; } else { // m_NextMessage complete offset = m_NextMessageLen - m_NextMessageOffset; memcpy (m_NextMessage + m_NextMessageOffset, m_Buffer, offset); HandleNextMessage (m_NextMessage); delete[] m_NextMessage; m_NextMessage = nullptr; } } while (offset < bytes_transferred) { auto msgLen = bufbe32toh (m_Buffer + offset + I2CP_HEADER_LENGTH_OFFSET) + I2CP_HEADER_SIZE; if (msgLen > 0xFFFF) // 64K { LogPrint (eLogError, "I2CP: message length ", msgLen, " exceeds 64K. Terminated"); Terminate (); return; } if (msgLen <= bytes_transferred - offset) { HandleNextMessage (m_Buffer + offset); offset += msgLen; } else { m_NextMessageLen = msgLen; m_NextMessageOffset = bytes_transferred - offset; m_NextMessage = new uint8_t[m_NextMessageLen]; memcpy (m_NextMessage, m_Buffer + offset, m_NextMessageOffset); offset = bytes_transferred; } } Receive (); } } void I2CPSession::HandleNextMessage (const uint8_t * buf) { auto handler = m_Owner.GetMessagesHandlers ()[buf[I2CP_HEADER_TYPE_OFFSET]]; if (handler) (this->*handler)(buf + I2CP_HEADER_SIZE, bufbe32toh (buf + I2CP_HEADER_LENGTH_OFFSET)); else LogPrint (eLogError, "I2CP: Unknown I2CP messsage ", (int)buf[I2CP_HEADER_TYPE_OFFSET]); } void I2CPSession::Terminate () { if (m_Destination) { m_Destination->Stop (); m_Destination = nullptr; } if (m_Socket) { m_Socket->close (); m_Socket = nullptr; } m_Owner.RemoveSession (GetSessionID ()); } void I2CPSession::SendI2CPMessage (uint8_t type, const uint8_t * payload, size_t len) { auto l = len + I2CP_HEADER_SIZE; uint8_t * buf = new uint8_t[l]; htobe32buf (buf + I2CP_HEADER_LENGTH_OFFSET, len); buf[I2CP_HEADER_TYPE_OFFSET] = type; memcpy (buf + I2CP_HEADER_SIZE, payload, len); boost::asio::async_write (*m_Socket, boost::asio::buffer (buf, l), boost::asio::transfer_all (), std::bind(&I2CPSession::HandleI2CPMessageSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2, buf)); } void I2CPSession::HandleI2CPMessageSent (const boost::system::error_code& ecode, std::size_t bytes_transferred, const uint8_t * buf) { delete[] buf; if (ecode && ecode != boost::asio::error::operation_aborted) Terminate (); } std::string I2CPSession::ExtractString (const uint8_t * buf, size_t len) { uint8_t l = buf[0]; if (l > len) l = len; return std::string ((const char *)(buf + 1), l); } size_t I2CPSession::PutString (uint8_t * buf, size_t len, const std::string& str) { auto l = str.length (); if (l + 1 >= len) l = len - 1; if (l > 255) l = 255; // 1 byte max buf[0] = l; memcpy (buf + 1, str.c_str (), l); return l + 1; } void I2CPSession::ExtractMapping (const uint8_t * buf, size_t len, std::map& mapping) // TODO: move to Base.cpp { size_t offset = 0; while (offset < len) { std::string param = ExtractString (buf + offset, len - offset); offset += param.length (); if (buf[offset] != '=') { LogPrint (eLogWarning, "I2CP: Unexpected character ", buf[offset], " instead '=' after ", param); break; } offset++; std::string value = ExtractString (buf + offset, len - offset); offset += value.length (); if (buf[offset] != ';') { LogPrint (eLogWarning, "I2CP: Unexpected character ", buf[offset], " instead ';' after ", value); break; } offset++; mapping.insert (std::make_pair (param, value)); } } void I2CPSession::GetDateMessageHandler (const uint8_t * buf, size_t len) { // get version auto version = ExtractString (buf, len); auto l = version.length () + 1 + 8; uint8_t * payload = new uint8_t[l]; // set date auto ts = i2p::util::GetMillisecondsSinceEpoch (); htobe64buf (payload, ts); // echo vesrion back PutString (payload + 8, l - 8, version); SendI2CPMessage (I2CP_SET_DATE_MESSAGE, payload, l); delete[] payload; } void I2CPSession::CreateSessionMessageHandler (const uint8_t * buf, size_t len) { auto identity = std::make_shared(); size_t offset = identity->FromBuffer (buf, len); if (!offset) { LogPrint (eLogError, "I2CP: create session maformed identity"); SendSessionStatusMessage (3); // invalid return; } uint16_t optionsSize = bufbe16toh (buf + offset); offset += 2; if (optionsSize > len - offset) { LogPrint (eLogError, "I2CP: options size ", optionsSize, "exceeds message size"); SendSessionStatusMessage (3); // invalid return; } std::map params; ExtractMapping (buf + offset, optionsSize, params); offset += optionsSize; // options if (params[I2CP_PARAM_MESSAGE_RELIABILITY] == "none") m_IsSendAccepted = false; offset += 8; // date if (identity->Verify (buf, offset, buf + offset)) // signature { bool isPublic = true; if (params[I2CP_PARAM_DONT_PUBLISH_LEASESET] == "true") isPublic = false; if (!m_Destination) { m_Destination = std::make_shared(shared_from_this (), identity, isPublic, params); SendSessionStatusMessage (1); // created LogPrint (eLogDebug, "I2CP: session ", m_SessionID, " created"); m_Destination->Start (); } else { LogPrint (eLogError, "I2CP: session already exists"); SendSessionStatusMessage (4); // refused } } else { LogPrint (eLogError, "I2CP: create session signature verification falied"); SendSessionStatusMessage (3); // invalid } } void I2CPSession::DestroySessionMessageHandler (const uint8_t * buf, size_t len) { SendSessionStatusMessage (0); // destroy LogPrint (eLogDebug, "I2CP: session ", m_SessionID, " destroyed"); Terminate (); } void I2CPSession::ReconfigureSessionMessageHandler (const uint8_t * buf, size_t len) { // TODO: implement actual reconfiguration SendSessionStatusMessage (2); // updated } void I2CPSession::SendSessionStatusMessage (uint8_t status) { uint8_t buf[3]; htobe16buf (buf, m_SessionID); buf[2] = status; SendI2CPMessage (I2CP_SESSION_STATUS_MESSAGE, buf, 3); } void I2CPSession::SendMessageStatusMessage (uint32_t nonce, I2CPMessageStatus status) { if (!nonce) return; // don't send status with zero nonce uint8_t buf[15]; htobe16buf (buf, m_SessionID); htobe32buf (buf + 2, m_MessageID++); buf[6] = (uint8_t)status; memset (buf + 7, 0, 4); // size htobe32buf (buf + 11, nonce); SendI2CPMessage (I2CP_MESSAGE_STATUS_MESSAGE, buf, 15); } void I2CPSession::CreateLeaseSetMessageHandler (const uint8_t * buf, size_t len) { uint16_t sessionID = bufbe16toh (buf); if (sessionID == m_SessionID) { size_t offset = 2; if (m_Destination) { offset += i2p::crypto::DSA_PRIVATE_KEY_LENGTH; // skip signing private key // we always assume this field as 20 bytes (DSA) regardless actual size // instead of //offset += m_Destination->GetIdentity ()->GetSigningPrivateKeyLen (); m_Destination->SetEncryptionPrivateKey (buf + offset); offset += 256; m_Destination->LeaseSetCreated (buf + offset, len - offset); } } else LogPrint (eLogError, "I2CP: unexpected sessionID ", sessionID); } void I2CPSession::SendMessageMessageHandler (const uint8_t * buf, size_t len) { uint16_t sessionID = bufbe16toh (buf); if (sessionID == m_SessionID) { size_t offset = 2; if (m_Destination) { i2p::data::IdentityEx identity; offset += identity.FromBuffer (buf + offset, len - offset); uint32_t payloadLen = bufbe32toh (buf + offset); offset += 4; uint32_t nonce = bufbe32toh (buf + offset + payloadLen); if (m_IsSendAccepted) SendMessageStatusMessage (nonce, eI2CPMessageStatusAccepted); // accepted m_Destination->SendMsgTo (buf + offset, payloadLen, identity.GetIdentHash (), nonce); } } else LogPrint (eLogError, "I2CP: unexpected sessionID ", sessionID); } void I2CPSession::SendMessageExpiresMessageHandler (const uint8_t * buf, size_t len) { SendMessageMessageHandler (buf, len - 8); // ignore flags(2) and expiration(6) } void I2CPSession::HostLookupMessageHandler (const uint8_t * buf, size_t len) { uint16_t sessionID = bufbe16toh (buf); if (sessionID == m_SessionID) { uint32_t requestID = bufbe32toh (buf + 2); //uint32_t timeout = bufbe32toh (buf + 6); i2p::data::IdentHash ident; switch (buf[10]) { case 0: // hash ident = i2p::data::IdentHash (buf + 11); break; case 1: // address { auto name = ExtractString (buf + 11, len - 11); if (!i2p::client::context.GetAddressBook ().GetIdentHash (name, ident)) { LogPrint (eLogError, "I2CP: address ", name, " not found"); SendHostReplyMessage (requestID, nullptr); return; } break; } default: LogPrint (eLogError, "I2CP: request type ", (int)buf[10], " is not supported"); SendHostReplyMessage (requestID, nullptr); return; } if (m_Destination) { auto ls = m_Destination->FindLeaseSet (ident); if (ls) SendHostReplyMessage (requestID, ls->GetIdentity ()); else { auto s = shared_from_this (); m_Destination->RequestDestination (ident, [s, requestID](std::shared_ptr leaseSet) { s->SendHostReplyMessage (requestID, leaseSet ? leaseSet->GetIdentity () : nullptr); }); } } else SendHostReplyMessage (requestID, nullptr); } else LogPrint (eLogError, "I2CP: unexpected sessionID ", sessionID); } void I2CPSession::SendHostReplyMessage (uint32_t requestID, std::shared_ptr identity) { if (identity) { size_t l = identity->GetFullLen () + 7; uint8_t * buf = new uint8_t[l]; htobe16buf (buf, m_SessionID); htobe32buf (buf + 2, requestID); buf[6] = 0; // result code identity->ToBuffer (buf + 7, l - 7); SendI2CPMessage (I2CP_HOST_REPLY_MESSAGE, buf, l); delete[] buf; } else { uint8_t buf[7]; htobe16buf (buf, m_SessionID); htobe32buf (buf + 2, requestID); buf[6] = 1; // result code SendI2CPMessage (I2CP_HOST_REPLY_MESSAGE, buf, 7); } } void I2CPSession::DestLookupMessageHandler (const uint8_t * buf, size_t len) { if (m_Destination) { auto ls = m_Destination->FindLeaseSet (buf); if (ls) { auto l = ls->GetIdentity ()->GetFullLen (); uint8_t * identBuf = new uint8_t[l]; ls->GetIdentity ()->ToBuffer (identBuf, l); SendI2CPMessage (I2CP_DEST_REPLY_MESSAGE, identBuf, l); delete[] identBuf; } else { auto s = shared_from_this (); i2p::data::IdentHash ident (buf); m_Destination->RequestDestination (ident, [s, ident](std::shared_ptr leaseSet) { if (leaseSet) // found { auto l = leaseSet->GetIdentity ()->GetFullLen (); uint8_t * identBuf = new uint8_t[l]; leaseSet->GetIdentity ()->ToBuffer (identBuf, l); s->SendI2CPMessage (I2CP_DEST_REPLY_MESSAGE, identBuf, l); delete[] identBuf; } else s->SendI2CPMessage (I2CP_DEST_REPLY_MESSAGE, ident, 32); // not found }); } } else SendI2CPMessage (I2CP_DEST_REPLY_MESSAGE, buf, 32); } void I2CPSession::GetBandwidthLimitsMessageHandler (const uint8_t * buf, size_t len) { uint8_t limits[64]; memset (limits, 0, 64); htobe32buf (limits, i2p::transport::transports.GetInBandwidth ()); // inbound htobe32buf (limits + 4, i2p::transport::transports.GetOutBandwidth ()); // outbound SendI2CPMessage (I2CP_BANDWIDTH_LIMITS_MESSAGE, limits, 64); } void I2CPSession::SendMessagePayloadMessage (const uint8_t * payload, size_t len) { // we don't use SendI2CPMessage to eliminate additional copy auto l = len + 10 + I2CP_HEADER_SIZE; uint8_t * buf = new uint8_t[l]; htobe32buf (buf + I2CP_HEADER_LENGTH_OFFSET, len + 10); buf[I2CP_HEADER_TYPE_OFFSET] = I2CP_MESSAGE_PAYLOAD_MESSAGE; htobe16buf (buf + I2CP_HEADER_SIZE, m_SessionID); htobe32buf (buf + I2CP_HEADER_SIZE + 2, m_MessageID++); htobe32buf (buf + I2CP_HEADER_SIZE + 6, len); memcpy (buf + I2CP_HEADER_SIZE + 10, payload, len); boost::asio::async_write (*m_Socket, boost::asio::buffer (buf, l), boost::asio::transfer_all (), std::bind(&I2CPSession::HandleI2CPMessageSent, shared_from_this (), std::placeholders::_1, std::placeholders::_2, buf)); } I2CPServer::I2CPServer (const std::string& interface, int port): m_IsRunning (false), m_Thread (nullptr), m_Acceptor (m_Service, boost::asio::ip::tcp::endpoint(boost::asio::ip::address::from_string(interface), port)) { memset (m_MessagesHandlers, 0, sizeof (m_MessagesHandlers)); m_MessagesHandlers[I2CP_GET_DATE_MESSAGE] = &I2CPSession::GetDateMessageHandler; m_MessagesHandlers[I2CP_CREATE_SESSION_MESSAGE] = &I2CPSession::CreateSessionMessageHandler; m_MessagesHandlers[I2CP_DESTROY_SESSION_MESSAGE] = &I2CPSession::DestroySessionMessageHandler; m_MessagesHandlers[I2CP_RECONFIGURE_SESSION_MESSAGE] = &I2CPSession::ReconfigureSessionMessageHandler; m_MessagesHandlers[I2CP_CREATE_LEASESET_MESSAGE] = &I2CPSession::CreateLeaseSetMessageHandler; m_MessagesHandlers[I2CP_SEND_MESSAGE_MESSAGE] = &I2CPSession::SendMessageMessageHandler; m_MessagesHandlers[I2CP_SEND_MESSAGE_EXPIRES_MESSAGE] = &I2CPSession::SendMessageExpiresMessageHandler; m_MessagesHandlers[I2CP_HOST_LOOKUP_MESSAGE] = &I2CPSession::HostLookupMessageHandler; m_MessagesHandlers[I2CP_DEST_LOOKUP_MESSAGE] = &I2CPSession::DestLookupMessageHandler; m_MessagesHandlers[I2CP_GET_BANDWIDTH_LIMITS_MESSAGE] = &I2CPSession::GetBandwidthLimitsMessageHandler; } I2CPServer::~I2CPServer () { if (m_IsRunning) Stop (); } void I2CPServer::Start () { Accept (); m_IsRunning = true; m_Thread = new std::thread (std::bind (&I2CPServer::Run, this)); } void I2CPServer::Stop () { m_IsRunning = false; m_Acceptor.cancel (); for (auto it: m_Sessions) it.second->Stop (); m_Sessions.clear (); m_Service.stop (); if (m_Thread) { m_Thread->join (); delete m_Thread; m_Thread = nullptr; } } void I2CPServer::Run () { while (m_IsRunning) { try { m_Service.run (); } catch (std::exception& ex) { LogPrint (eLogError, "I2CP: runtime exception: ", ex.what ()); } } } void I2CPServer::Accept () { auto newSocket = std::make_shared (m_Service); m_Acceptor.async_accept (*newSocket, std::bind (&I2CPServer::HandleAccept, this, std::placeholders::_1, newSocket)); } void I2CPServer::HandleAccept(const boost::system::error_code& ecode, std::shared_ptr socket) { if (!ecode && socket) { boost::system::error_code ec; auto ep = socket->remote_endpoint (ec); if (!ec) { LogPrint (eLogDebug, "I2CP: new connection from ", ep); auto session = std::make_shared(*this, socket); m_Sessions[session->GetSessionID ()] = session; session->Start (); } else LogPrint (eLogError, "I2CP: incoming connection error ", ec.message ()); } else LogPrint (eLogError, "I2CP: accept error: ", ecode.message ()); if (ecode != boost::asio::error::operation_aborted) Accept (); } void I2CPServer::RemoveSession (uint16_t sessionID) { m_Sessions.erase (sessionID); } } }