/** * FreeRDP: A Remote Desktop Protocol Implementation * Network Transport Layer * * Copyright 2011 Vic Lee * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef _WIN32 #include #include #endif /* _WIN32 */ #ifdef HAVE_VALGRIND_MEMCHECK_H #include #endif #include "tpkt.h" #include "fastpath.h" #include "transport.h" #include "rdp.h" #define TAG FREERDP_TAG("core.transport") #define BUFFER_SIZE 16384 static void* transport_client_thread(void* arg); wStream* transport_send_stream_init(rdpTransport* transport, int size) { wStream* s; if (!(s = StreamPool_Take(transport->ReceivePool, size))) return NULL; if (!Stream_EnsureCapacity(s, size)) { Stream_Release(s); return NULL; } Stream_SetPosition(s, 0); return s; } BOOL transport_attach(rdpTransport* transport, int sockfd) { BIO* socketBio; BIO* bufferedBio; socketBio = BIO_new(BIO_s_simple_socket()); if (!socketBio) return FALSE; BIO_set_fd(socketBio, sockfd, BIO_CLOSE); bufferedBio = BIO_new(BIO_s_buffered_socket()); if (!bufferedBio) return FALSE; bufferedBio = BIO_push(bufferedBio, socketBio); transport->frontBio = bufferedBio; return TRUE; } BOOL transport_connect_rdp(rdpTransport* transport) { /* RDP encryption */ return TRUE; } BOOL transport_connect_tls(rdpTransport* transport) { int tlsStatus; rdpTls* tls = NULL; rdpContext* context = transport->context; rdpSettings* settings = transport->settings; if (transport->GatewayEnabled) { tls = transport->tls = tls_new(settings); transport->layer = TRANSPORT_LAYER_TSG_TLS; } else { tls = transport->tls = tls_new(settings); transport->layer = TRANSPORT_LAYER_TLS; } transport->tls = tls; tls->hostname = settings->ServerHostname; tls->port = settings->ServerPort; if (tls->port == 0) tls->port = 3389; tls->isGatewayTransport = FALSE; tlsStatus = tls_connect(tls, transport->frontBio); if (tlsStatus < 1) { if (tlsStatus < 0) { if (!freerdp_get_last_error(context)) freerdp_set_last_error(context, FREERDP_ERROR_TLS_CONNECT_FAILED); } else { if (!freerdp_get_last_error(context)) freerdp_set_last_error(context, FREERDP_ERROR_CONNECT_CANCELLED); } return FALSE; } transport->frontBio = tls->bio; if (!transport->frontBio) { WLog_ERR(TAG, "unable to prepend a filtering TLS bio"); return FALSE; } return TRUE; } BOOL transport_connect_nla(rdpTransport* transport) { rdpContext* context = transport->context; rdpSettings* settings = context->settings; freerdp* instance = context->instance; rdpRdp* rdp = context->rdp; if (!transport_connect_tls(transport)) return FALSE; if (!settings->Authentication) return TRUE; rdp->nla = nla_new(instance, transport, settings); if (!rdp->nla) return FALSE; transport_set_nla_mode(transport, TRUE); if (settings->AuthenticationServiceClass) { rdp->nla->ServicePrincipalName = nla_make_spn(settings->AuthenticationServiceClass, settings->ServerHostname); if (!rdp->nla->ServicePrincipalName) return FALSE; } if (nla_client_begin(rdp->nla) < 0) { if (!freerdp_get_last_error(context)) freerdp_set_last_error(context, FREERDP_ERROR_AUTHENTICATION_FAILED); transport_set_nla_mode(transport, FALSE); return FALSE; } rdp_client_transition_to_state(rdp, CONNECTION_STATE_NLA); return TRUE; } BOOL transport_connect(rdpTransport* transport, const char* hostname, UINT16 port, int timeout) { int sockfd; BOOL status = FALSE; rdpSettings* settings = transport->settings; transport->async = settings->AsyncTransport; if (transport->GatewayEnabled) { if (!status && settings->GatewayHttpTransport) { transport->rdg = rdg_new(transport); if (!transport->rdg) return FALSE; status = rdg_connect(transport->rdg, hostname, port, timeout); if (status) { transport->frontBio = transport->rdg->frontBio; BIO_set_nonblock(transport->frontBio, 0); transport->layer = TRANSPORT_LAYER_TSG; status = TRUE; } else { rdg_free(transport->rdg); transport->rdg = NULL; } } if (!status && settings->GatewayRpcTransport) { transport->tsg = tsg_new(transport); if (!transport->tsg) return FALSE; status = tsg_connect(transport->tsg, hostname, port, timeout); if (status) { transport->frontBio = transport->tsg->bio; transport->layer = TRANSPORT_LAYER_TSG; status = TRUE; } else { tsg_free(transport->tsg); transport->tsg = NULL; } } } else { sockfd = freerdp_tcp_connect(settings, hostname, port, timeout); if (sockfd < 1) return FALSE; transport_attach(transport, sockfd); status = TRUE; } if (status) { if (transport->async) { transport->stopEvent = CreateEvent(NULL, TRUE, FALSE, NULL); transport->thread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE) transport_client_thread, transport, 0, NULL); } } return status; } BOOL transport_accept_rdp(rdpTransport* transport) { /* RDP encryption */ return TRUE; } BOOL transport_accept_tls(rdpTransport* transport) { rdpSettings* settings = transport->settings; if (!transport->tls) transport->tls = tls_new(transport->settings); transport->layer = TRANSPORT_LAYER_TLS; if (!tls_accept(transport->tls, transport->frontBio, settings->CertificateFile, settings->PrivateKeyFile)) return FALSE; transport->frontBio = transport->tls->bio; return TRUE; } BOOL transport_accept_nla(rdpTransport* transport) { rdpSettings* settings = transport->settings; freerdp* instance = (freerdp*) settings->instance; if (!transport->tls) transport->tls = tls_new(transport->settings); transport->layer = TRANSPORT_LAYER_TLS; if (!tls_accept(transport->tls, transport->frontBio, settings->CertificateFile, settings->PrivateKeyFile)) return FALSE; transport->frontBio = transport->tls->bio; /* Network Level Authentication */ if (!settings->Authentication) return TRUE; if (!transport->nla) { transport->nla = nla_new(instance, transport, settings); transport_set_nla_mode(transport, TRUE); } if (nla_authenticate(transport->nla) < 0) { WLog_ERR(TAG, "client authentication failure"); transport_set_nla_mode(transport, FALSE); nla_free(transport->nla); transport->nla = NULL; tls_set_alert_code(transport->tls, TLS_ALERT_LEVEL_FATAL, TLS_ALERT_DESCRIPTION_ACCESS_DENIED); return FALSE; } /* don't free nla module yet, we need to copy the credentials from it first */ transport_set_nla_mode(transport, FALSE); return TRUE; } int transport_read_layer(rdpTransport* transport, BYTE* data, int bytes) { int read = 0; int status = -1; if (!transport->frontBio) { transport->layer = TRANSPORT_LAYER_CLOSED; return -1; } while (read < bytes) { status = BIO_read(transport->frontBio, data + read, bytes - read); if (status <= 0) { if (!transport->frontBio || !BIO_should_retry(transport->frontBio)) { /* something unexpected happened, let's close */ transport->layer = TRANSPORT_LAYER_CLOSED; return -1; } /* non blocking will survive a partial read */ if (!transport->blocking) return read; /* blocking means that we can't continue until we have read the number of requested bytes */ if (BIO_wait_read(transport->frontBio, 100) < 0) { WLog_ERR(TAG, "error when selecting for read"); return -1; } continue; } #ifdef HAVE_VALGRIND_MEMCHECK_H VALGRIND_MAKE_MEM_DEFINED(data + read, bytes - read); #endif read += status; } return read; } /** * @brief Tries to read toRead bytes from the specified transport * * Try to read toRead bytes from the transport to the stream. * In case it was not possible to read toRead bytes 0 is returned. The stream is always advanced by the * number of bytes read. * * The function assumes that the stream has enough capacity to hold the data. * * @param[in] transport rdpTransport * @param[in] s wStream * @param[in] toRead number of bytes to read * @return < 0 on error; 0 if not enough data is available (non blocking mode); 1 toRead bytes read */ static int transport_read_layer_bytes(rdpTransport* transport, wStream* s, unsigned int toRead) { int status; status = transport_read_layer(transport, Stream_Pointer(s), toRead); if (status <= 0) return status; Stream_Seek(s, status); return status == toRead ? 1 : 0; } /** * @brief Try to read a complete PDU (NLA, fast-path or tpkt) from the underlying transport. * * If possible a complete PDU is read, in case of non blocking transport this might not succeed. * Except in case of an error the passed stream will point to the last byte read (correct * position). When the pdu read is completed the stream is sealed and the pointer set to 0 * * @param[in] transport rdpTransport * @param[in] s wStream * @return < 0 on error; 0 if not enough data is available (non blocking mode); > 0 number of * bytes of the *complete* pdu read */ int transport_read_pdu(rdpTransport* transport, wStream* s) { int status; int position; int pduLength; BYTE* header; position = 0; pduLength = 0; if (!transport) return -1; if (!s) return -1; position = Stream_GetPosition(s); /* Make sure there is enough space for the longest header within the stream */ if (!Stream_EnsureCapacity(s, 4)) return -1; /* Make sure at least two bytes are read for further processing */ if (position < 2 && (status = transport_read_layer_bytes(transport, s, 2 - position)) != 1) { /* No data available at the moment */ return status; } /* update position value for further checks */ position = Stream_GetPosition(s); header = Stream_Buffer(s); if (transport->NlaMode) { /* * In case NlaMode is set TSRequest package(s) are expected * 0x30 = DER encoded data with these bits set: * bit 6 P/C constructed * bit 5 tag number - sequence */ if (header[0] == 0x30) { /* TSRequest (NLA) */ if (header[1] & 0x80) { if ((header[1] & ~(0x80)) == 1) { /* check for header bytes already was readed in previous calls */ if (position < 3 && (status = transport_read_layer_bytes(transport, s, 3 - position)) != 1) return status; pduLength = header[2]; pduLength += 3; } else if ((header[1] & ~(0x80)) == 2) { /* check for header bytes already was readed in previous calls */ if (position < 4 && (status = transport_read_layer_bytes(transport, s, 4 - position)) != 1) return status; pduLength = (header[2] << 8) | header[3]; pduLength += 4; } else { WLog_ERR(TAG, "Error reading TSRequest!"); return -1; } } else { pduLength = header[1]; pduLength += 2; } } } else { if (header[0] == 0x03) { /* TPKT header */ /* check for header bytes already was readed in previous calls */ if (position < 4 && (status = transport_read_layer_bytes(transport, s, 4 - position)) != 1) return status; pduLength = (header[2] << 8) | header[3]; /* min and max values according to ITU-T Rec. T.123 (01/2007) section 8 */ if (pduLength < 7 || pduLength > 0xFFFF) { WLog_ERR(TAG, "tpkt - invalid pduLength: %d", pduLength); return -1; } } else { /* Fast-Path Header */ if (header[1] & 0x80) { /* check for header bytes already was readed in previous calls */ if (position < 3 && (status = transport_read_layer_bytes(transport, s, 3 - position)) != 1) return status; pduLength = ((header[1] & 0x7F) << 8) | header[2]; } else pduLength = header[1]; /* * fast-path has 7 bits for length so the maximum size, including headers is 0x8000 * The theoretical minimum fast-path PDU consists only of two header bytes plus one * byte for data (e.g. fast-path input synchronize pdu) */ if (pduLength < 3 || pduLength > 0x8000) { WLog_ERR(TAG, "fast path - invalid pduLength: %d", pduLength); return -1; } } } if (!Stream_EnsureCapacity(s, Stream_GetPosition(s) + pduLength)) return -1; status = transport_read_layer_bytes(transport, s, pduLength - Stream_GetPosition(s)); if (status != 1) return status; if (Stream_GetPosition(s) >= pduLength) WLog_Packet(WLog_Get(TAG), WLOG_TRACE, Stream_Buffer(s), pduLength, WLOG_PACKET_INBOUND); Stream_SealLength(s); Stream_SetPosition(s, 0); return Stream_Length(s); } int transport_write(rdpTransport* transport, wStream* s) { int length; int status = -1; EnterCriticalSection(&(transport->WriteLock)); length = Stream_GetPosition(s); Stream_SetPosition(s, 0); if (length > 0) { WLog_Packet(WLog_Get(TAG), WLOG_TRACE, Stream_Buffer(s), length, WLOG_PACKET_OUTBOUND); } while (length > 0) { status = BIO_write(transport->frontBio, Stream_Pointer(s), length); if (status <= 0) { /* the buffered BIO that is at the end of the chain always says OK for writing, * so a retry means that for any reason we need to read. The most probable * is a SSL or TSG BIO in the chain. */ if (!BIO_should_retry(transport->frontBio)) goto out_cleanup; /* non-blocking can live with blocked IOs */ if (!transport->blocking) goto out_cleanup; if (BIO_wait_write(transport->frontBio, 100) < 0) { WLog_ERR(TAG, "error when selecting for write"); status = -1; goto out_cleanup; } continue; } if (transport->blocking || transport->settings->WaitForOutputBufferFlush) { while (BIO_write_blocked(transport->frontBio)) { if (BIO_wait_write(transport->frontBio, 100) < 0) { WLog_ERR(TAG, "error when selecting for write"); status = -1; goto out_cleanup; } if (BIO_flush(transport->frontBio) < 1) { WLog_ERR(TAG, "error when flushing outputBuffer"); status = -1; goto out_cleanup; } } } length -= status; Stream_Seek(s, status); } out_cleanup: if (status < 0) { /* A write error indicates that the peer has dropped the connection */ transport->layer = TRANSPORT_LAYER_CLOSED; } if (s->pool) Stream_Release(s); LeaveCriticalSection(&(transport->WriteLock)); return status; } UINT32 transport_get_event_handles(rdpTransport* transport, HANDLE* events) { UINT32 nCount = 0; if (!transport->GatewayEnabled) { if (events) BIO_get_event(transport->frontBio, &events[nCount]); nCount++; } else { if (transport->rdg) { nCount += rdg_get_event_handles(transport->rdg, events); } else if (transport->tsg) { nCount += tsg_get_event_handles(transport->tsg, events); } } return nCount; } void transport_get_fds(rdpTransport* transport, void** rfds, int* rcount) { UINT32 index; UINT32 nCount; HANDLE events[64]; nCount = transport_get_event_handles(transport, events); for (index = 0; index < nCount; index++) { rfds[*rcount] = GetEventWaitObject(events[index]); (*rcount)++; } } BOOL transport_is_write_blocked(rdpTransport* transport) { return BIO_write_blocked(transport->frontBio); } int transport_drain_output_buffer(rdpTransport* transport) { BOOL status = FALSE; if (BIO_write_blocked(transport->frontBio)) { if (BIO_flush(transport->frontBio) < 1) return -1; status |= BIO_write_blocked(transport->frontBio); } return status; } int transport_check_fds(rdpTransport* transport) { int status; int recv_status; wStream* received; if (!transport) return -1; /** * Loop through and read all available PDUs. Since multiple * PDUs can exist, it's important to deliver them all before * returning. Otherwise we run the risk of having a thread * wait for a socket to get signaled that data is available * (which may never happen). */ for (;;) { /** * Note: transport_read_pdu tries to read one PDU from * the transport layer. * The ReceiveBuffer might have a position > 0 in case of a non blocking * transport. If transport_read_pdu returns 0 the pdu couldn't be read at * this point. * Note that transport->ReceiveBuffer is replaced after each iteration * of this loop with a fresh stream instance from a pool. */ if ((status = transport_read_pdu(transport, transport->ReceiveBuffer)) <= 0) { return status; } received = transport->ReceiveBuffer; if (!(transport->ReceiveBuffer = StreamPool_Take(transport->ReceivePool, 0))) return -1; /** * status: * -1: error * 0: success * 1: redirection */ recv_status = transport->ReceiveCallback(transport, received, transport->ReceiveExtra); Stream_Release(received); /* session redirection or activation */ if (recv_status == 1 || recv_status == 2) { return recv_status; } if (recv_status < 0) return -1; } return 0; } BOOL transport_set_blocking_mode(rdpTransport* transport, BOOL blocking) { transport->blocking = blocking; if (!BIO_set_nonblock(transport->frontBio, blocking ? FALSE : TRUE)) return FALSE; return TRUE; } void transport_set_gateway_enabled(rdpTransport* transport, BOOL GatewayEnabled) { transport->GatewayEnabled = GatewayEnabled; } void transport_set_nla_mode(rdpTransport* transport, BOOL NlaMode) { transport->NlaMode = NlaMode; } void transport_stop(rdpTransport* transport) { if (transport->async) { if (transport->stopEvent) { SetEvent(transport->stopEvent); WaitForSingleObject(transport->thread, INFINITE); CloseHandle(transport->thread); CloseHandle(transport->stopEvent); transport->thread = NULL; transport->stopEvent = NULL; } } } BOOL transport_disconnect(rdpTransport* transport) { BOOL status = TRUE; if (!transport) return FALSE; transport_stop(transport); if (transport->tls) { tls_free(transport->tls); transport->tls = NULL; } else { if (transport->frontBio) BIO_free(transport->frontBio); } if (transport->tsg) { tsg_free(transport->tsg); transport->tsg = NULL; } if (transport->rdg) { rdg_free(transport->rdg); transport->rdg = NULL; } transport->frontBio = NULL; transport->layer = TRANSPORT_LAYER_TCP; return status; } static void* transport_client_thread(void* arg) { DWORD status; DWORD nCount; HANDLE handles[64]; rdpTransport* transport = (rdpTransport*) arg; rdpContext* context = transport->context; rdpRdp* rdp = context->rdp; WLog_DBG(TAG, "Starting transport thread"); nCount = 0; handles[nCount++] = transport->stopEvent; handles[nCount++] = transport->connectedEvent; status = WaitForMultipleObjects(nCount, handles, FALSE, INFINITE); if (WaitForSingleObject(transport->stopEvent, 0) == WAIT_OBJECT_0) { WLog_DBG(TAG, "Terminating transport thread"); ExitThread(0); return NULL; } WLog_DBG(TAG, "Asynchronous transport activated"); while (1) { nCount = 0; handles[nCount++] = transport->stopEvent; nCount += freerdp_get_event_handles(context, &handles[nCount]); status = WaitForMultipleObjects(nCount, handles, FALSE, INFINITE); if (transport->layer == TRANSPORT_LAYER_CLOSED) { rdp_set_error_info(rdp, ERRINFO_PEER_DISCONNECTED); break; } if (WaitForSingleObject(transport->stopEvent, 0) == WAIT_OBJECT_0) break; if (WaitForMultipleObjects(nCount - 1, &handles[1], FALSE, 0) != WAIT_TIMEOUT) { if (!freerdp_check_event_handles(context)) { rdp_set_error_info(rdp, ERRINFO_PEER_DISCONNECTED); break; } } } WLog_DBG(TAG, "Terminating transport thread"); ExitThread(0); return NULL; } rdpTransport* transport_new(rdpContext* context) { rdpTransport* transport; transport = (rdpTransport*) calloc(1, sizeof(rdpTransport)); if (!transport) return NULL; transport->context = context; transport->settings = context->settings; transport->ReceivePool = StreamPool_New(TRUE, BUFFER_SIZE); if (!transport->ReceivePool) goto out_free_transport; /* receive buffer for non-blocking read. */ transport->ReceiveBuffer = StreamPool_Take(transport->ReceivePool, 0); if (!transport->ReceiveBuffer) goto out_free_receivepool; transport->connectedEvent = CreateEvent(NULL, TRUE, FALSE, NULL); if (!transport->connectedEvent || transport->connectedEvent == INVALID_HANDLE_VALUE) goto out_free_receivebuffer; transport->blocking = TRUE; transport->GatewayEnabled = FALSE; transport->layer = TRANSPORT_LAYER_TCP; if (!InitializeCriticalSectionAndSpinCount(&(transport->ReadLock), 4000)) goto out_free_connectedEvent; if (!InitializeCriticalSectionAndSpinCount(&(transport->WriteLock), 4000)) goto out_free_readlock; return transport; out_free_readlock: DeleteCriticalSection(&(transport->ReadLock)); out_free_connectedEvent: CloseHandle(transport->connectedEvent); out_free_receivebuffer: StreamPool_Return(transport->ReceivePool, transport->ReceiveBuffer); out_free_receivepool: StreamPool_Free(transport->ReceivePool); out_free_transport: free(transport); return NULL; } void transport_free(rdpTransport* transport) { if (!transport) return; transport_disconnect(transport); if (transport->ReceiveBuffer) Stream_Release(transport->ReceiveBuffer); StreamPool_Free(transport->ReceivePool); CloseHandle(transport->connectedEvent); DeleteCriticalSection(&(transport->ReadLock)); DeleteCriticalSection(&(transport->WriteLock)); free(transport); }