#include #include #include #include #include "Base.h" #include "Log.h" #include "Crypto.h" #include "I2PEndian.h" #include "Timestamp.h" #include "RouterContext.h" #include "NetDb.h" #include "Tunnel.h" #include "Transports.h" #include "Garlic.h" #include "I2NPProtocol.h" using namespace i2p::transport; namespace i2p { std::shared_ptr NewI2NPMessage () { return std::make_shared >(); } std::shared_ptr NewI2NPShortMessage () { return std::make_shared >(); } std::shared_ptr NewI2NPMessage (size_t len) { return (len < I2NP_MAX_SHORT_MESSAGE_SIZE/2) ? NewI2NPShortMessage () : NewI2NPMessage (); } void I2NPMessage::FillI2NPMessageHeader (I2NPMessageType msgType, uint32_t replyMsgID) { SetTypeID (msgType); if (!replyMsgID) RAND_bytes ((uint8_t *)&replyMsgID, 4); SetMsgID (replyMsgID); SetExpiration (i2p::util::GetMillisecondsSinceEpoch () + 8000); // 8 secs means initial RTT UpdateSize (); UpdateChks (); } void I2NPMessage::RenewI2NPMessageHeader () { uint32_t msgID; RAND_bytes ((uint8_t *)&msgID, 4); SetMsgID (msgID); SetExpiration (i2p::util::GetMillisecondsSinceEpoch () + 8000); } bool I2NPMessage::IsExpired () const { return i2p::util::GetMillisecondsSinceEpoch () > GetExpiration (); } std::shared_ptr CreateI2NPMessage (I2NPMessageType msgType, const uint8_t * buf, size_t len, uint32_t replyMsgID) { auto msg = NewI2NPMessage (len); if (msg->Concat (buf, len) < len) LogPrint (eLogError, "I2NP: message length ", len, " exceeds max length ", msg->maxLen); msg->FillI2NPMessageHeader (msgType, replyMsgID); return msg; } std::shared_ptr CreateI2NPMessage (const uint8_t * buf, size_t len, std::shared_ptr from) { auto msg = NewI2NPMessage (); if (msg->offset + len < msg->maxLen) { memcpy (msg->GetBuffer (), buf, len); msg->len = msg->offset + len; msg->from = from; } else LogPrint (eLogError, "I2NP: message length ", len, " exceeds max length"); return msg; } std::shared_ptr CreateDeliveryStatusMsg (uint32_t msgID) { auto m = NewI2NPShortMessage (); uint8_t * buf = m->GetPayload (); if (msgID) { htobe32buf (buf + DELIVERY_STATUS_MSGID_OFFSET, msgID); htobe64buf (buf + DELIVERY_STATUS_TIMESTAMP_OFFSET, i2p::util::GetMillisecondsSinceEpoch ()); } else // for SSU establishment { RAND_bytes ((uint8_t *)&msgID, 4); htobe32buf (buf + DELIVERY_STATUS_MSGID_OFFSET, msgID); htobe64buf (buf + DELIVERY_STATUS_TIMESTAMP_OFFSET, 2); // netID = 2 } m->len += DELIVERY_STATUS_SIZE; m->FillI2NPMessageHeader (eI2NPDeliveryStatus); return m; } std::shared_ptr CreateRouterInfoDatabaseLookupMsg (const uint8_t * key, const uint8_t * from, uint32_t replyTunnelID, bool exploratory, std::set * excludedPeers) { auto m = excludedPeers ? NewI2NPMessage () : NewI2NPShortMessage (); uint8_t * buf = m->GetPayload (); memcpy (buf, key, 32); // key buf += 32; memcpy (buf, from, 32); // from buf += 32; uint8_t flag = exploratory ? DATABASE_LOOKUP_TYPE_EXPLORATORY_LOOKUP : DATABASE_LOOKUP_TYPE_ROUTERINFO_LOOKUP; if (replyTunnelID) { *buf = flag | DATABASE_LOOKUP_DELIVERY_FLAG; // set delivery flag htobe32buf (buf+1, replyTunnelID); buf += 5; } else { *buf = flag; // flag buf++; } if (excludedPeers) { int cnt = excludedPeers->size (); htobe16buf (buf, cnt); buf += 2; for (auto& it: *excludedPeers) { memcpy (buf, it, 32); buf += 32; } } else { // nothing to exclude htobuf16 (buf, 0); buf += 2; } m->len += (buf - m->GetPayload ()); m->FillI2NPMessageHeader (eI2NPDatabaseLookup); return m; } std::shared_ptr CreateLeaseSetDatabaseLookupMsg (const i2p::data::IdentHash& dest, const std::set& excludedFloodfills, const i2p::tunnel::InboundTunnel * replyTunnel, const uint8_t * replyKey, const uint8_t * replyTag) { int cnt = excludedFloodfills.size (); auto m = cnt > 0 ? NewI2NPMessage () : NewI2NPShortMessage (); uint8_t * buf = m->GetPayload (); memcpy (buf, dest, 32); // key buf += 32; memcpy (buf, replyTunnel->GetNextIdentHash (), 32); // reply tunnel GW buf += 32; *buf = DATABASE_LOOKUP_DELIVERY_FLAG | DATABASE_LOOKUP_ENCYPTION_FLAG | DATABASE_LOOKUP_TYPE_LEASESET_LOOKUP; // flags htobe32buf (buf + 1, replyTunnel->GetNextTunnelID ()); // reply tunnel ID buf += 5; // excluded htobe16buf (buf, cnt); buf += 2; if (cnt > 0) { for (auto& it: excludedFloodfills) { memcpy (buf, it, 32); buf += 32; } } // encryption memcpy (buf, replyKey, 32); buf[32] = 1; // 1 tag memcpy (buf + 33, replyTag, 32); buf += 65; m->len += (buf - m->GetPayload ()); m->FillI2NPMessageHeader (eI2NPDatabaseLookup); return m; } std::shared_ptr CreateDatabaseSearchReply (const i2p::data::IdentHash& ident, std::vector routers) { auto m = NewI2NPShortMessage (); uint8_t * buf = m->GetPayload (); size_t len = 0; memcpy (buf, ident, 32); len += 32; buf[len] = routers.size (); len++; for (auto it: routers) { memcpy (buf + len, it, 32); len += 32; } memcpy (buf + len, i2p::context.GetRouterInfo ().GetIdentHash (), 32); len += 32; m->len += len; m->FillI2NPMessageHeader (eI2NPDatabaseSearchReply); return m; } std::shared_ptr CreateDatabaseStoreMsg (std::shared_ptr router, uint32_t replyToken) { if (!router) // we send own RouterInfo router = context.GetSharedRouterInfo (); auto m = NewI2NPShortMessage (); uint8_t * payload = m->GetPayload (); memcpy (payload + DATABASE_STORE_KEY_OFFSET, router->GetIdentHash (), 32); payload[DATABASE_STORE_TYPE_OFFSET] = 0; // RouterInfo htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, replyToken); uint8_t * buf = payload + DATABASE_STORE_HEADER_SIZE; if (replyToken) { memset (buf, 0, 4); // zero tunnelID means direct reply buf += 4; memcpy (buf, router->GetIdentHash (), 32); buf += 32; } uint8_t * sizePtr = buf; buf += 2; m->len += (buf - payload); // payload size i2p::data::GzipDeflator deflator; size_t size = deflator.Deflate (router->GetBuffer (), router->GetBufferLen (), buf, m->maxLen -m->len); if (size) { htobe16buf (sizePtr, size); // size m->len += size; } else m = nullptr; if (m) m->FillI2NPMessageHeader (eI2NPDatabaseStore); return m; } std::shared_ptr CreateDatabaseStoreMsg (std::shared_ptr leaseSet, uint32_t replyToken) { if (!leaseSet) return nullptr; auto m = NewI2NPShortMessage (); uint8_t * payload = m->GetPayload (); memcpy (payload + DATABASE_STORE_KEY_OFFSET, leaseSet->GetIdentHash (), 32); payload[DATABASE_STORE_TYPE_OFFSET] = 1; // LeaseSet htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, replyToken); size_t size = DATABASE_STORE_HEADER_SIZE; if (replyToken) { auto leases = leaseSet->GetNonExpiredLeases (); if (leases.size () > 0) { htobe32buf (payload + size, leases[0].tunnelID); size += 4; // reply tunnelID memcpy (payload + size, leases[0].tunnelGateway, 32); size += 32; // reply tunnel gateway } else htobe32buf (payload + DATABASE_STORE_REPLY_TOKEN_OFFSET, 0); } memcpy (payload + size, leaseSet->GetBuffer (), leaseSet->GetBufferLen ()); size += leaseSet->GetBufferLen (); m->len += size; m->FillI2NPMessageHeader (eI2NPDatabaseStore); return m; } bool IsRouterInfoMsg (std::shared_ptr msg) { if (!msg || msg->GetTypeID () != eI2NPDatabaseStore) return false; return !msg->GetPayload ()[DATABASE_STORE_TYPE_OFFSET]; // 0- RouterInfo } bool HandleBuildRequestRecords (int num, uint8_t * records, uint8_t * clearText) { for (int i = 0; i < num; i++) { uint8_t * record = records + i*TUNNEL_BUILD_RECORD_SIZE; if (!memcmp (record + BUILD_REQUEST_RECORD_TO_PEER_OFFSET, (const uint8_t *)i2p::context.GetRouterInfo ().GetIdentHash (), 16)) { LogPrint (eLogDebug, "I2NP: Build request record ", i, " is ours"); i2p::crypto::ElGamalDecrypt (i2p::context.GetEncryptionPrivateKey (), record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET, clearText); // replace record to reply if (i2p::context.AcceptsTunnels () && i2p::tunnel::tunnels.GetTransitTunnels ().size () <= MAX_NUM_TRANSIT_TUNNELS && !i2p::transport::transports.IsBandwidthExceeded ()) { i2p::tunnel::TransitTunnel * transitTunnel = i2p::tunnel::CreateTransitTunnel ( bufbe32toh (clearText + BUILD_REQUEST_RECORD_RECEIVE_TUNNEL_OFFSET), clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, bufbe32toh (clearText + BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), clearText + BUILD_REQUEST_RECORD_LAYER_KEY_OFFSET, clearText + BUILD_REQUEST_RECORD_IV_KEY_OFFSET, clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET] & 0x80, clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET ] & 0x40); i2p::tunnel::tunnels.AddTransitTunnel (transitTunnel); record[BUILD_RESPONSE_RECORD_RET_OFFSET] = 0; } else record[BUILD_RESPONSE_RECORD_RET_OFFSET] = 30; // always reject with bandwidth reason (30) //TODO: fill filler SHA256 (record + BUILD_RESPONSE_RECORD_PADDING_OFFSET, BUILD_RESPONSE_RECORD_PADDING_SIZE + 1, // + 1 byte of ret record + BUILD_RESPONSE_RECORD_HASH_OFFSET); // encrypt reply i2p::crypto::CBCEncryption encryption; for (int j = 0; j < num; j++) { encryption.SetKey (clearText + BUILD_REQUEST_RECORD_REPLY_KEY_OFFSET); encryption.SetIV (clearText + BUILD_REQUEST_RECORD_REPLY_IV_OFFSET); uint8_t * reply = records + j*TUNNEL_BUILD_RECORD_SIZE; encryption.Encrypt(reply, TUNNEL_BUILD_RECORD_SIZE, reply); } return true; } } return false; } void HandleVariableTunnelBuildMsg (uint32_t replyMsgID, uint8_t * buf, size_t len) { int num = buf[0]; LogPrint (eLogDebug, "I2NP: VariableTunnelBuild ", num, " records"); auto tunnel = i2p::tunnel::tunnels.GetPendingInboundTunnel (replyMsgID); if (tunnel) { // endpoint of inbound tunnel LogPrint (eLogDebug, "I2NP: VariableTunnelBuild reply for tunnel ", tunnel->GetTunnelID ()); if (tunnel->HandleTunnelBuildResponse (buf, len)) { LogPrint (eLogInfo, "I2NP: Inbound tunnel ", tunnel->GetTunnelID (), " has been created"); tunnel->SetState (i2p::tunnel::eTunnelStateEstablished); i2p::tunnel::tunnels.AddInboundTunnel (tunnel); } else { LogPrint (eLogInfo, "I2NP: Inbound tunnel ", tunnel->GetTunnelID (), " has been declined"); tunnel->SetState (i2p::tunnel::eTunnelStateBuildFailed); } } else { uint8_t clearText[BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE]; if (HandleBuildRequestRecords (num, buf + 1, clearText)) { if (clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET] & 0x40) // we are endpoint of outboud tunnel { // so we send it to reply tunnel transports.SendMessage (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, CreateTunnelGatewayMsg (bufbe32toh (clearText + BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), eI2NPVariableTunnelBuildReply, buf, len, bufbe32toh (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); } else transports.SendMessage (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, CreateI2NPMessage (eI2NPVariableTunnelBuild, buf, len, bufbe32toh (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); } } } void HandleTunnelBuildMsg (uint8_t * buf, size_t len) { uint8_t clearText[BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE]; if (HandleBuildRequestRecords (NUM_TUNNEL_BUILD_RECORDS, buf, clearText)) { if (clearText[BUILD_REQUEST_RECORD_FLAG_OFFSET] & 0x40) // we are endpoint of outbound tunnel { // so we send it to reply tunnel transports.SendMessage (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, CreateTunnelGatewayMsg (bufbe32toh (clearText + BUILD_REQUEST_RECORD_NEXT_TUNNEL_OFFSET), eI2NPTunnelBuildReply, buf, len, bufbe32toh (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); } else transports.SendMessage (clearText + BUILD_REQUEST_RECORD_NEXT_IDENT_OFFSET, CreateI2NPMessage (eI2NPTunnelBuild, buf, len, bufbe32toh (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET))); } } void HandleVariableTunnelBuildReplyMsg (uint32_t replyMsgID, uint8_t * buf, size_t len) { LogPrint (eLogDebug, "I2NP: VariableTunnelBuildReplyMsg replyMsgID=", replyMsgID); auto tunnel = i2p::tunnel::tunnels.GetPendingOutboundTunnel (replyMsgID); if (tunnel) { // reply for outbound tunnel if (tunnel->HandleTunnelBuildResponse (buf, len)) { LogPrint (eLogInfo, "I2NP: Outbound tunnel ", tunnel->GetTunnelID (), " has been created"); tunnel->SetState (i2p::tunnel::eTunnelStateEstablished); i2p::tunnel::tunnels.AddOutboundTunnel (tunnel); } else { LogPrint (eLogInfo, "I2NP: Outbound tunnel ", tunnel->GetTunnelID (), " has been declined"); tunnel->SetState (i2p::tunnel::eTunnelStateBuildFailed); } } else LogPrint (eLogWarning, "I2NP: Pending tunnel for message ", replyMsgID, " not found"); } std::shared_ptr CreateTunnelDataMsg (const uint8_t * buf) { auto msg = NewI2NPShortMessage (); msg->Concat (buf, i2p::tunnel::TUNNEL_DATA_MSG_SIZE); msg->FillI2NPMessageHeader (eI2NPTunnelData); return msg; } std::shared_ptr CreateTunnelDataMsg (uint32_t tunnelID, const uint8_t * payload) { auto msg = NewI2NPShortMessage (); htobe32buf (msg->GetPayload (), tunnelID); msg->len += 4; // tunnelID msg->Concat (payload, i2p::tunnel::TUNNEL_DATA_MSG_SIZE - 4); msg->FillI2NPMessageHeader (eI2NPTunnelData); return msg; } std::shared_ptr CreateEmptyTunnelDataMsg () { auto msg = NewI2NPShortMessage (); msg->len += i2p::tunnel::TUNNEL_DATA_MSG_SIZE; return msg; } std::shared_ptr CreateTunnelGatewayMsg (uint32_t tunnelID, const uint8_t * buf, size_t len) { auto msg = NewI2NPMessage (len); uint8_t * payload = msg->GetPayload (); htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID); htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len); msg->len += TUNNEL_GATEWAY_HEADER_SIZE; if (msg->Concat (buf, len) < len) LogPrint (eLogError, "I2NP: tunnel gateway buffer overflow ", msg->maxLen); msg->FillI2NPMessageHeader (eI2NPTunnelGateway); return msg; } std::shared_ptr CreateTunnelGatewayMsg (uint32_t tunnelID, std::shared_ptr msg) { if (msg->offset >= I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE) { // message is capable to be used without copying uint8_t * payload = msg->GetBuffer () - TUNNEL_GATEWAY_HEADER_SIZE; htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID); int len = msg->GetLength (); htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len); msg->offset -= (I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE); msg->len = msg->offset + I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE +len; msg->FillI2NPMessageHeader (eI2NPTunnelGateway); return msg; } else return CreateTunnelGatewayMsg (tunnelID, msg->GetBuffer (), msg->GetLength ()); } std::shared_ptr CreateTunnelGatewayMsg (uint32_t tunnelID, I2NPMessageType msgType, const uint8_t * buf, size_t len, uint32_t replyMsgID) { auto msg = NewI2NPMessage (len); size_t gatewayMsgOffset = I2NP_HEADER_SIZE + TUNNEL_GATEWAY_HEADER_SIZE; msg->offset += gatewayMsgOffset; msg->len += gatewayMsgOffset; if (msg->Concat (buf, len) < len) LogPrint (eLogError, "I2NP: tunnel gateway buffer overflow ", msg->maxLen); msg->FillI2NPMessageHeader (msgType, replyMsgID); // create content message len = msg->GetLength (); msg->offset -= gatewayMsgOffset; uint8_t * payload = msg->GetPayload (); htobe32buf (payload + TUNNEL_GATEWAY_HEADER_TUNNELID_OFFSET, tunnelID); htobe16buf (payload + TUNNEL_GATEWAY_HEADER_LENGTH_OFFSET, len); msg->FillI2NPMessageHeader (eI2NPTunnelGateway); // gateway message return msg; } size_t GetI2NPMessageLength (const uint8_t * msg) { return bufbe16toh (msg + I2NP_HEADER_SIZE_OFFSET) + I2NP_HEADER_SIZE; } void HandleI2NPMessage (uint8_t * msg, size_t len) { uint8_t typeID = msg[I2NP_HEADER_TYPEID_OFFSET]; uint32_t msgID = bufbe32toh (msg + I2NP_HEADER_MSGID_OFFSET); LogPrint (eLogDebug, "I2NP: msg received len=", len,", type=", (int)typeID, ", msgID=", (unsigned int)msgID); uint8_t * buf = msg + I2NP_HEADER_SIZE; int size = bufbe16toh (msg + I2NP_HEADER_SIZE_OFFSET); switch (typeID) { case eI2NPVariableTunnelBuild: HandleVariableTunnelBuildMsg (msgID, buf, size); break; case eI2NPVariableTunnelBuildReply: HandleVariableTunnelBuildReplyMsg (msgID, buf, size); break; case eI2NPTunnelBuild: HandleTunnelBuildMsg (buf, size); break; case eI2NPTunnelBuildReply: // TODO: break; default: LogPrint (eLogWarning, "I2NP: Unexpected message ", (int)typeID); } } void HandleI2NPMessage (std::shared_ptr msg) { if (msg) { uint8_t typeID = msg->GetTypeID (); LogPrint (eLogDebug, "I2NP: Handling message with type ", (int)typeID); switch (typeID) { case eI2NPTunnelData: i2p::tunnel::tunnels.PostTunnelData (msg); break; case eI2NPTunnelGateway: i2p::tunnel::tunnels.PostTunnelData (msg); break; case eI2NPGarlic: { if (msg->from) { if (msg->from->GetTunnelPool ()) msg->from->GetTunnelPool ()->ProcessGarlicMessage (msg); else LogPrint (eLogInfo, "I2NP: Local destination for garlic doesn't exist anymore"); } else i2p::context.ProcessGarlicMessage (msg); break; } case eI2NPDatabaseStore: case eI2NPDatabaseSearchReply: case eI2NPDatabaseLookup: // forward to netDb i2p::data::netdb.PostI2NPMsg (msg); break; case eI2NPDeliveryStatus: { if (msg->from && msg->from->GetTunnelPool ()) msg->from->GetTunnelPool ()->ProcessDeliveryStatus (msg); else i2p::context.ProcessDeliveryStatusMessage (msg); break; } case eI2NPVariableTunnelBuild: case eI2NPVariableTunnelBuildReply: case eI2NPTunnelBuild: case eI2NPTunnelBuildReply: // forward to tunnel thread i2p::tunnel::tunnels.PostTunnelData (msg); break; default: HandleI2NPMessage (msg->GetBuffer (), msg->GetLength ()); } } } I2NPMessagesHandler::~I2NPMessagesHandler () { Flush (); } void I2NPMessagesHandler::PutNextMessage (std::shared_ptr msg) { if (msg) { switch (msg->GetTypeID ()) { case eI2NPTunnelData: m_TunnelMsgs.push_back (msg); break; case eI2NPTunnelGateway: m_TunnelGatewayMsgs.push_back (msg); break; default: HandleI2NPMessage (msg); } } } void I2NPMessagesHandler::Flush () { if (!m_TunnelMsgs.empty ()) { i2p::tunnel::tunnels.PostTunnelData (m_TunnelMsgs); m_TunnelMsgs.clear (); } if (!m_TunnelGatewayMsgs.empty ()) { i2p::tunnel::tunnels.PostTunnelData (m_TunnelGatewayMsgs); m_TunnelGatewayMsgs.clear (); } } }