//===-- GDBRemoteCommunication.cpp ------------------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// #include "GDBRemoteCommunication.h" // C Includes #include #include #include // C++ Includes // Other libraries and framework includes #include "lldb/Core/Log.h" #include "lldb/Core/RegularExpression.h" #include "lldb/Core/StreamFile.h" #include "lldb/Core/StreamString.h" #include "lldb/Host/ConnectionFileDescriptor.h" #include "lldb/Host/FileSpec.h" #include "lldb/Host/Host.h" #include "lldb/Host/HostInfo.h" #include "lldb/Host/Pipe.h" #include "lldb/Host/Socket.h" #include "lldb/Host/StringConvert.h" #include "lldb/Host/ThreadLauncher.h" #include "lldb/Host/TimeValue.h" #include "lldb/Target/Platform.h" #include "lldb/Target/Process.h" #include "llvm/ADT/SmallString.h" // Project includes #include "ProcessGDBRemoteLog.h" #if defined(__APPLE__) # define DEBUGSERVER_BASENAME "debugserver" #else # define DEBUGSERVER_BASENAME "lldb-server" #endif #if defined (HAVE_LIBCOMPRESSION) #include #endif #if defined (HAVE_LIBZ) #include #endif using namespace lldb; using namespace lldb_private; using namespace lldb_private::process_gdb_remote; GDBRemoteCommunication::History::History (uint32_t size) : m_packets(), m_curr_idx (0), m_total_packet_count (0), m_dumped_to_log (false) { m_packets.resize(size); } GDBRemoteCommunication::History::~History () { } void GDBRemoteCommunication::History::AddPacket (char packet_char, PacketType type, uint32_t bytes_transmitted) { const size_t size = m_packets.size(); if (size > 0) { const uint32_t idx = GetNextIndex(); m_packets[idx].packet.assign (1, packet_char); m_packets[idx].type = type; m_packets[idx].bytes_transmitted = bytes_transmitted; m_packets[idx].packet_idx = m_total_packet_count; m_packets[idx].tid = Host::GetCurrentThreadID(); } } void GDBRemoteCommunication::History::AddPacket (const std::string &src, uint32_t src_len, PacketType type, uint32_t bytes_transmitted) { const size_t size = m_packets.size(); if (size > 0) { const uint32_t idx = GetNextIndex(); m_packets[idx].packet.assign (src, 0, src_len); m_packets[idx].type = type; m_packets[idx].bytes_transmitted = bytes_transmitted; m_packets[idx].packet_idx = m_total_packet_count; m_packets[idx].tid = Host::GetCurrentThreadID(); } } void GDBRemoteCommunication::History::Dump (Stream &strm) const { const uint32_t size = GetNumPacketsInHistory (); const uint32_t first_idx = GetFirstSavedPacketIndex (); const uint32_t stop_idx = m_curr_idx + size; for (uint32_t i = first_idx; i < stop_idx; ++i) { const uint32_t idx = NormalizeIndex (i); const Entry &entry = m_packets[idx]; if (entry.type == ePacketTypeInvalid || entry.packet.empty()) break; strm.Printf ("history[%u] tid=0x%4.4" PRIx64 " <%4u> %s packet: %s\n", entry.packet_idx, entry.tid, entry.bytes_transmitted, (entry.type == ePacketTypeSend) ? "send" : "read", entry.packet.c_str()); } } void GDBRemoteCommunication::History::Dump (Log *log) const { if (log && !m_dumped_to_log) { m_dumped_to_log = true; const uint32_t size = GetNumPacketsInHistory (); const uint32_t first_idx = GetFirstSavedPacketIndex (); const uint32_t stop_idx = m_curr_idx + size; for (uint32_t i = first_idx; i < stop_idx; ++i) { const uint32_t idx = NormalizeIndex (i); const Entry &entry = m_packets[idx]; if (entry.type == ePacketTypeInvalid || entry.packet.empty()) break; log->Printf ("history[%u] tid=0x%4.4" PRIx64 " <%4u> %s packet: %s", entry.packet_idx, entry.tid, entry.bytes_transmitted, (entry.type == ePacketTypeSend) ? "send" : "read", entry.packet.c_str()); } } } //---------------------------------------------------------------------- // GDBRemoteCommunication constructor //---------------------------------------------------------------------- GDBRemoteCommunication::GDBRemoteCommunication(const char *comm_name, const char *listener_name) : Communication(comm_name), #ifdef LLDB_CONFIGURATION_DEBUG m_packet_timeout (1000), #else m_packet_timeout (1), #endif m_echo_number(0), m_supports_qEcho (eLazyBoolCalculate), m_sequence_mutex (Mutex::eMutexTypeRecursive), m_public_is_running (false), m_private_is_running (false), m_history (512), m_send_acks (true), m_compression_type (CompressionType::None), m_listen_url () { } //---------------------------------------------------------------------- // Destructor //---------------------------------------------------------------------- GDBRemoteCommunication::~GDBRemoteCommunication() { if (IsConnected()) { Disconnect(); } // Stop the communications read thread which is used to parse all // incoming packets. This function will block until the read // thread returns. if (m_read_thread_enabled) StopReadThread(); } char GDBRemoteCommunication::CalculcateChecksum (const char *payload, size_t payload_length) { int checksum = 0; for (size_t i = 0; i < payload_length; ++i) checksum += payload[i]; return checksum & 255; } size_t GDBRemoteCommunication::SendAck () { Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS)); ConnectionStatus status = eConnectionStatusSuccess; char ch = '+'; const size_t bytes_written = Write (&ch, 1, status, NULL); if (log) log->Printf ("<%4" PRIu64 "> send packet: %c", (uint64_t)bytes_written, ch); m_history.AddPacket (ch, History::ePacketTypeSend, bytes_written); return bytes_written; } size_t GDBRemoteCommunication::SendNack () { Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS)); ConnectionStatus status = eConnectionStatusSuccess; char ch = '-'; const size_t bytes_written = Write (&ch, 1, status, NULL); if (log) log->Printf("<%4" PRIu64 "> send packet: %c", (uint64_t)bytes_written, ch); m_history.AddPacket (ch, History::ePacketTypeSend, bytes_written); return bytes_written; } GDBRemoteCommunication::PacketResult GDBRemoteCommunication::SendPacket (const char *payload, size_t payload_length) { Mutex::Locker locker(m_sequence_mutex); return SendPacketNoLock (payload, payload_length); } GDBRemoteCommunication::PacketResult GDBRemoteCommunication::SendPacketNoLock (const char *payload, size_t payload_length) { if (IsConnected()) { StreamString packet(0, 4, eByteOrderBig); packet.PutChar('$'); packet.Write (payload, payload_length); packet.PutChar('#'); packet.PutHex8(CalculcateChecksum (payload, payload_length)); Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS)); ConnectionStatus status = eConnectionStatusSuccess; const char *packet_data = packet.GetData(); const size_t packet_length = packet.GetSize(); size_t bytes_written = Write (packet_data, packet_length, status, NULL); if (log) { size_t binary_start_offset = 0; if (strncmp(packet_data, "$vFile:pwrite:", strlen("$vFile:pwrite:")) == 0) { const char *first_comma = strchr(packet_data, ','); if (first_comma) { const char *second_comma = strchr(first_comma + 1, ','); if (second_comma) binary_start_offset = second_comma - packet_data + 1; } } // If logging was just enabled and we have history, then dump out what // we have to the log so we get the historical context. The Dump() call that // logs all of the packet will set a boolean so that we don't dump this more // than once if (!m_history.DidDumpToLog ()) m_history.Dump (log); if (binary_start_offset) { StreamString strm; // Print non binary data header strm.Printf("<%4" PRIu64 "> send packet: %.*s", (uint64_t)bytes_written, (int)binary_start_offset, packet_data); const uint8_t *p; // Print binary data exactly as sent for (p = (const uint8_t*)packet_data + binary_start_offset; *p != '#'; ++p) strm.Printf("\\x%2.2x", *p); // Print the checksum strm.Printf("%*s", (int)3, p); log->PutCString(strm.GetString().c_str()); } else log->Printf("<%4" PRIu64 "> send packet: %.*s", (uint64_t)bytes_written, (int)packet_length, packet_data); } m_history.AddPacket (packet.GetString(), packet_length, History::ePacketTypeSend, bytes_written); if (bytes_written == packet_length) { if (GetSendAcks ()) return GetAck (); else return PacketResult::Success; } else { if (log) log->Printf ("error: failed to send packet: %.*s", (int)packet_length, packet_data); } } return PacketResult::ErrorSendFailed; } GDBRemoteCommunication::PacketResult GDBRemoteCommunication::GetAck () { StringExtractorGDBRemote packet; PacketResult result = ReadPacket (packet, GetPacketTimeoutInMicroSeconds (), false); if (result == PacketResult::Success) { if (packet.GetResponseType() == StringExtractorGDBRemote::ResponseType::eAck) return PacketResult::Success; else return PacketResult::ErrorSendAck; } return result; } bool GDBRemoteCommunication::GetSequenceMutex (Mutex::Locker& locker, const char *failure_message) { if (IsRunning()) return locker.TryLock (m_sequence_mutex, failure_message); locker.Lock (m_sequence_mutex); return true; } bool GDBRemoteCommunication::WaitForNotRunningPrivate (const TimeValue *timeout_ptr) { return m_private_is_running.WaitForValueEqualTo (false, timeout_ptr, NULL); } GDBRemoteCommunication::PacketResult GDBRemoteCommunication::ReadPacket (StringExtractorGDBRemote &response, uint32_t timeout_usec, bool sync_on_timeout) { if (m_read_thread_enabled) return PopPacketFromQueue (response, timeout_usec); else return WaitForPacketWithTimeoutMicroSecondsNoLock (response, timeout_usec, sync_on_timeout); } // This function is called when a packet is requested. // A whole packet is popped from the packet queue and returned to the caller. // Packets are placed into this queue from the communication read thread. // See GDBRemoteCommunication::AppendBytesToCache. GDBRemoteCommunication::PacketResult GDBRemoteCommunication::PopPacketFromQueue (StringExtractorGDBRemote &response, uint32_t timeout_usec) { // Calculate absolute timeout value TimeValue timeout = TimeValue::Now(); timeout.OffsetWithMicroSeconds(timeout_usec); do { // scope for the mutex { // lock down the packet queue Mutex::Locker locker(m_packet_queue_mutex); // Wait on condition variable. if (m_packet_queue.size() == 0) m_condition_queue_not_empty.Wait(m_packet_queue_mutex, &timeout); if (m_packet_queue.size() > 0) { // get the front element of the queue response = m_packet_queue.front(); // remove the front element m_packet_queue.pop(); // we got a packet return PacketResult::Success; } } // Disconnected if (!IsConnected()) return PacketResult::ErrorDisconnected; // Loop while not timed out } while (TimeValue::Now() < timeout); return PacketResult::ErrorReplyTimeout; } GDBRemoteCommunication::PacketResult GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock (StringExtractorGDBRemote &packet, uint32_t timeout_usec, bool sync_on_timeout) { uint8_t buffer[8192]; Error error; Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS | GDBR_LOG_VERBOSE)); // Check for a packet from our cache first without trying any reading... if (CheckForPacket(NULL, 0, packet) != PacketType::Invalid) return PacketResult::Success; bool timed_out = false; bool disconnected = false; while (IsConnected() && !timed_out) { lldb::ConnectionStatus status = eConnectionStatusNoConnection; size_t bytes_read = Read (buffer, sizeof(buffer), timeout_usec, status, &error); if (log) log->Printf ("%s: Read (buffer, (sizeof(buffer), timeout_usec = 0x%x, status = %s, error = %s) => bytes_read = %" PRIu64, __PRETTY_FUNCTION__, timeout_usec, Communication::ConnectionStatusAsCString (status), error.AsCString(), (uint64_t)bytes_read); if (bytes_read > 0) { if (CheckForPacket(buffer, bytes_read, packet) != PacketType::Invalid) return PacketResult::Success; } else { switch (status) { case eConnectionStatusTimedOut: case eConnectionStatusInterrupted: if (sync_on_timeout) { //------------------------------------------------------------------ /// Sync the remote GDB server and make sure we get a response that /// corresponds to what we send. /// /// Sends a "qEcho" packet and makes sure it gets the exact packet /// echoed back. If the qEcho packet isn't supported, we send a qC /// packet and make sure we get a valid thread ID back. We use the /// "qC" packet since its response if very unique: is responds with /// "QC%x" where %x is the thread ID of the current thread. This /// makes the response unique enough from other packet responses to /// ensure we are back on track. /// /// This packet is needed after we time out sending a packet so we /// can ensure that we are getting the response for the packet we /// are sending. There are no sequence IDs in the GDB remote /// protocol (there used to be, but they are not supported anymore) /// so if you timeout sending packet "abc", you might then send /// packet "cde" and get the response for the previous "abc" packet. /// Many responses are "OK" or "" (unsupported) or "EXX" (error) so /// many responses for packets can look like responses for other /// packets. So if we timeout, we need to ensure that we can get /// back on track. If we can't get back on track, we must /// disconnect. //------------------------------------------------------------------ bool sync_success = false; bool got_actual_response = false; // We timed out, we need to sync back up with the char echo_packet[32]; int echo_packet_len = 0; RegularExpression response_regex; if (m_supports_qEcho == eLazyBoolYes) { echo_packet_len = ::snprintf (echo_packet, sizeof(echo_packet), "qEcho:%u", ++m_echo_number); std::string regex_str = "^"; regex_str += echo_packet; regex_str += "$"; response_regex.Compile(regex_str.c_str()); } else { echo_packet_len = ::snprintf (echo_packet, sizeof(echo_packet), "qC"); response_regex.Compile("^QC[0-9A-Fa-f]+$"); } PacketResult echo_packet_result = SendPacketNoLock (echo_packet, echo_packet_len); if (echo_packet_result == PacketResult::Success) { const uint32_t max_retries = 3; uint32_t successful_responses = 0; for (uint32_t i=0; i")); break; case eConnectionStatusEndOfFile: case eConnectionStatusNoConnection: case eConnectionStatusLostConnection: case eConnectionStatusError: disconnected = true; Disconnect(); break; } } } packet.Clear (); if (disconnected) return PacketResult::ErrorDisconnected; if (timed_out) return PacketResult::ErrorReplyTimeout; else return PacketResult::ErrorReplyFailed; } bool GDBRemoteCommunication::DecompressPacket () { Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS)); if (!CompressionIsEnabled()) return true; size_t pkt_size = m_bytes.size(); // Smallest possible compressed packet is $N#00 - an uncompressed empty reply, most commonly indicating // an unsupported packet. Anything less than 5 characters, it's definitely not a compressed packet. if (pkt_size < 5) return true; if (m_bytes[0] != '$' && m_bytes[0] != '%') return true; if (m_bytes[1] != 'C' && m_bytes[1] != 'N') return true; size_t hash_mark_idx = m_bytes.find ('#'); if (hash_mark_idx == std::string::npos) return true; if (hash_mark_idx + 2 >= m_bytes.size()) return true; if (!::isxdigit (m_bytes[hash_mark_idx + 1]) || !::isxdigit (m_bytes[hash_mark_idx + 2])) return true; size_t content_length = pkt_size - 5; // not counting '$', 'C' | 'N', '#', & the two hex checksum chars size_t content_start = 2; // The first character of the compressed/not-compressed text of the packet size_t checksum_idx = hash_mark_idx + 1; // The first character of the two hex checksum characters // Normally size_of_first_packet == m_bytes.size() but m_bytes may contain multiple packets. // size_of_first_packet is the size of the initial packet which we'll replace with the decompressed // version of, leaving the rest of m_bytes unmodified. size_t size_of_first_packet = hash_mark_idx + 3; // Compressed packets ("$C") start with a base10 number which is the size of the uncompressed payload, // then a : and then the compressed data. e.g. $C1024:#00 // Update content_start and content_length to only include the part of the packet. uint64_t decompressed_bufsize = ULONG_MAX; if (m_bytes[1] == 'C') { size_t i = content_start; while (i < hash_mark_idx && isdigit(m_bytes[i])) i++; if (i < hash_mark_idx && m_bytes[i] == ':') { i++; content_start = i; content_length = hash_mark_idx - content_start; std::string bufsize_str (m_bytes.data() + 2, i - 2 - 1); errno = 0; decompressed_bufsize = ::strtoul (bufsize_str.c_str(), NULL, 10); if (errno != 0 || decompressed_bufsize == ULONG_MAX) { m_bytes.erase (0, size_of_first_packet); return false; } } } if (GetSendAcks ()) { char packet_checksum_cstr[3]; packet_checksum_cstr[0] = m_bytes[checksum_idx]; packet_checksum_cstr[1] = m_bytes[checksum_idx + 1]; packet_checksum_cstr[2] = '\0'; long packet_checksum = strtol (packet_checksum_cstr, NULL, 16); long actual_checksum = CalculcateChecksum (m_bytes.data() + 1, hash_mark_idx - 1); bool success = packet_checksum == actual_checksum; if (!success) { if (log) log->Printf ("error: checksum mismatch: %.*s expected 0x%2.2x, got 0x%2.2x", (int)(pkt_size), m_bytes.c_str(), (uint8_t)packet_checksum, (uint8_t)actual_checksum); } // Send the ack or nack if needed if (!success) { SendNack(); m_bytes.erase (0, size_of_first_packet); return false; } else { SendAck(); } } if (m_bytes[1] == 'N') { // This packet was not compressed -- delete the 'N' character at the // start and the packet may be processed as-is. m_bytes.erase(1, 1); return true; } // Reverse the gdb-remote binary escaping that was done to the compressed text to // guard characters like '$', '#', '}', etc. std::vector unescaped_content; unescaped_content.reserve (content_length); size_t i = content_start; while (i < hash_mark_idx) { if (m_bytes[i] == '}') { i++; unescaped_content.push_back (m_bytes[i] ^ 0x20); } else { unescaped_content.push_back (m_bytes[i]); } i++; } uint8_t *decompressed_buffer = nullptr; size_t decompressed_bytes = 0; if (decompressed_bufsize != ULONG_MAX) { decompressed_buffer = (uint8_t *) malloc (decompressed_bufsize + 1); if (decompressed_buffer == nullptr) { m_bytes.erase (0, size_of_first_packet); return false; } } #if defined (HAVE_LIBCOMPRESSION) // libcompression is weak linked so check that compression_decode_buffer() is available if (compression_decode_buffer != NULL && (m_compression_type == CompressionType::ZlibDeflate || m_compression_type == CompressionType::LZFSE || m_compression_type == CompressionType::LZ4)) { compression_algorithm compression_type; if (m_compression_type == CompressionType::ZlibDeflate) compression_type = COMPRESSION_ZLIB; else if (m_compression_type == CompressionType::LZFSE) compression_type = COMPRESSION_LZFSE; else if (m_compression_type == CompressionType::LZ4) compression_type = COMPRESSION_LZ4_RAW; else if (m_compression_type == CompressionType::LZMA) compression_type = COMPRESSION_LZMA; // If we have the expected size of the decompressed payload, we can allocate // the right-sized buffer and do it. If we don't have that information, we'll // need to try decoding into a big buffer and if the buffer wasn't big enough, // increase it and try again. if (decompressed_bufsize != ULONG_MAX && decompressed_buffer != nullptr) { decompressed_bytes = compression_decode_buffer (decompressed_buffer, decompressed_bufsize + 10 , (uint8_t*) unescaped_content.data(), unescaped_content.size(), NULL, compression_type); } } #endif #if defined (HAVE_LIBZ) if (decompressed_bytes == 0 && decompressed_bufsize != ULONG_MAX && decompressed_buffer != nullptr && m_compression_type == CompressionType::ZlibDeflate) { z_stream stream; memset (&stream, 0, sizeof (z_stream)); stream.next_in = (Bytef *) unescaped_content.data(); stream.avail_in = (uInt) unescaped_content.size(); stream.total_in = 0; stream.next_out = (Bytef *) decompressed_buffer; stream.avail_out = decompressed_bufsize; stream.total_out = 0; stream.zalloc = Z_NULL; stream.zfree = Z_NULL; stream.opaque = Z_NULL; if (inflateInit2 (&stream, -15) == Z_OK) { int status = inflate (&stream, Z_NO_FLUSH); inflateEnd (&stream); if (status == Z_STREAM_END) { decompressed_bytes = stream.total_out; } } } #endif if (decompressed_bytes == 0 || decompressed_buffer == nullptr) { if (decompressed_buffer) free (decompressed_buffer); m_bytes.erase (0, size_of_first_packet); return false; } std::string new_packet; new_packet.reserve (decompressed_bytes + 6); new_packet.push_back (m_bytes[0]); new_packet.append ((const char *) decompressed_buffer, decompressed_bytes); new_packet.push_back ('#'); if (GetSendAcks ()) { uint8_t decompressed_checksum = CalculcateChecksum ((const char *) decompressed_buffer, decompressed_bytes); char decompressed_checksum_str[3]; snprintf (decompressed_checksum_str, 3, "%02x", decompressed_checksum); new_packet.append (decompressed_checksum_str); } else { new_packet.push_back ('0'); new_packet.push_back ('0'); } m_bytes.replace (0, size_of_first_packet, new_packet.data(), new_packet.size()); free (decompressed_buffer); return true; } GDBRemoteCommunication::PacketType GDBRemoteCommunication::CheckForPacket (const uint8_t *src, size_t src_len, StringExtractorGDBRemote &packet) { // Put the packet data into the buffer in a thread safe fashion Mutex::Locker locker(m_bytes_mutex); Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS)); if (src && src_len > 0) { if (log && log->GetVerbose()) { StreamString s; log->Printf ("GDBRemoteCommunication::%s adding %u bytes: %.*s", __FUNCTION__, (uint32_t)src_len, (uint32_t)src_len, src); } m_bytes.append ((const char *)src, src_len); } bool isNotifyPacket = false; // Parse up the packets into gdb remote packets if (!m_bytes.empty()) { // end_idx must be one past the last valid packet byte. Start // it off with an invalid value that is the same as the current // index. size_t content_start = 0; size_t content_length = 0; size_t total_length = 0; size_t checksum_idx = std::string::npos; // Size of packet before it is decompressed, for logging purposes size_t original_packet_size = m_bytes.size(); if (CompressionIsEnabled()) { if (DecompressPacket() == false) { packet.Clear(); return GDBRemoteCommunication::PacketType::Standard; } } switch (m_bytes[0]) { case '+': // Look for ack case '-': // Look for cancel case '\x03': // ^C to halt target content_length = total_length = 1; // The command is one byte long... break; case '%': // Async notify packet isNotifyPacket = true; LLVM_FALLTHROUGH; case '$': // Look for a standard gdb packet? { size_t hash_pos = m_bytes.find('#'); if (hash_pos != std::string::npos) { if (hash_pos + 2 < m_bytes.size()) { checksum_idx = hash_pos + 1; // Skip the dollar sign content_start = 1; // Don't include the # in the content or the $ in the content length content_length = hash_pos - 1; total_length = hash_pos + 3; // Skip the # and the two hex checksum bytes } else { // Checksum bytes aren't all here yet content_length = std::string::npos; } } } break; default: { // We have an unexpected byte and we need to flush all bad // data that is in m_bytes, so we need to find the first // byte that is a '+' (ACK), '-' (NACK), \x03 (CTRL+C interrupt), // or '$' character (start of packet header) or of course, // the end of the data in m_bytes... const size_t bytes_len = m_bytes.size(); bool done = false; uint32_t idx; for (idx = 1; !done && idx < bytes_len; ++idx) { switch (m_bytes[idx]) { case '+': case '-': case '\x03': case '%': case '$': done = true; break; default: break; } } if (log) log->Printf ("GDBRemoteCommunication::%s tossing %u junk bytes: '%.*s'", __FUNCTION__, idx - 1, idx - 1, m_bytes.c_str()); m_bytes.erase(0, idx - 1); } break; } if (content_length == std::string::npos) { packet.Clear(); return GDBRemoteCommunication::PacketType::Invalid; } else if (total_length > 0) { // We have a valid packet... assert (content_length <= m_bytes.size()); assert (total_length <= m_bytes.size()); assert (content_length <= total_length); size_t content_end = content_start + content_length; bool success = true; std::string &packet_str = packet.GetStringRef(); if (log) { // If logging was just enabled and we have history, then dump out what // we have to the log so we get the historical context. The Dump() call that // logs all of the packet will set a boolean so that we don't dump this more // than once if (!m_history.DidDumpToLog ()) m_history.Dump (log); bool binary = false; // Only detect binary for packets that start with a '$' and have a '#CC' checksum if (m_bytes[0] == '$' && total_length > 4) { for (size_t i=0; !binary && i read packet: %c", (uint64_t) original_packet_size, (uint64_t)total_length, m_bytes[0]); else strm.Printf("<%4" PRIu64 "> read packet: %c", (uint64_t)total_length, m_bytes[0]); for (size_t i=content_start; iPutCString(strm.GetString().c_str()); } else { if (CompressionIsEnabled()) log->Printf("<%4" PRIu64 ":%" PRIu64 "> read packet: %.*s", (uint64_t) original_packet_size, (uint64_t)total_length, (int)(total_length), m_bytes.c_str()); else log->Printf("<%4" PRIu64 "> read packet: %.*s", (uint64_t)total_length, (int)(total_length), m_bytes.c_str()); } } m_history.AddPacket (m_bytes.c_str(), total_length, History::ePacketTypeRecv, total_length); // Clear packet_str in case there is some existing data in it. packet_str.clear(); // Copy the packet from m_bytes to packet_str expanding the // run-length encoding in the process. // Reserve enough byte for the most common case (no RLE used) packet_str.reserve(m_bytes.length()); for (std::string::const_iterator c = m_bytes.begin() + content_start; c != m_bytes.begin() + content_end; ++c) { if (*c == '*') { // '*' indicates RLE. Next character will give us the // repeat count and previous character is what is to be // repeated. char char_to_repeat = packet_str.back(); // Number of time the previous character is repeated int repeat_count = *++c + 3 - ' '; // We have the char_to_repeat and repeat_count. Now push // it in the packet. for (int i = 0; i < repeat_count; ++i) packet_str.push_back(char_to_repeat); } else if (*c == 0x7d) { // 0x7d is the escape character. The next character is to // be XOR'd with 0x20. char escapee = *++c ^ 0x20; packet_str.push_back(escapee); } else { packet_str.push_back(*c); } } if (m_bytes[0] == '$' || m_bytes[0] == '%') { assert (checksum_idx < m_bytes.size()); if (::isxdigit (m_bytes[checksum_idx+0]) || ::isxdigit (m_bytes[checksum_idx+1])) { if (GetSendAcks ()) { const char *packet_checksum_cstr = &m_bytes[checksum_idx]; char packet_checksum = strtol (packet_checksum_cstr, NULL, 16); char actual_checksum = CalculcateChecksum (packet_str.c_str(), packet_str.size()); success = packet_checksum == actual_checksum; if (!success) { if (log) log->Printf ("error: checksum mismatch: %.*s expected 0x%2.2x, got 0x%2.2x", (int)(total_length), m_bytes.c_str(), (uint8_t)packet_checksum, (uint8_t)actual_checksum); } // Send the ack or nack if needed if (!success) SendNack(); else SendAck(); } } else { success = false; if (log) log->Printf ("error: invalid checksum in packet: '%s'\n", m_bytes.c_str()); } } m_bytes.erase(0, total_length); packet.SetFilePos(0); if (isNotifyPacket) return GDBRemoteCommunication::PacketType::Notify; else return GDBRemoteCommunication::PacketType::Standard; } } packet.Clear(); return GDBRemoteCommunication::PacketType::Invalid; } Error GDBRemoteCommunication::StartListenThread (const char *hostname, uint16_t port) { Error error; if (m_listen_thread.IsJoinable()) { error.SetErrorString("listen thread already running"); } else { char listen_url[512]; if (hostname && hostname[0]) snprintf(listen_url, sizeof(listen_url), "listen://%s:%i", hostname, port); else snprintf(listen_url, sizeof(listen_url), "listen://%i", port); m_listen_url = listen_url; SetConnection(new ConnectionFileDescriptor()); m_listen_thread = ThreadLauncher::LaunchThread(listen_url, GDBRemoteCommunication::ListenThread, this, &error); } return error; } bool GDBRemoteCommunication::JoinListenThread () { if (m_listen_thread.IsJoinable()) m_listen_thread.Join(nullptr); return true; } lldb::thread_result_t GDBRemoteCommunication::ListenThread (lldb::thread_arg_t arg) { GDBRemoteCommunication *comm = (GDBRemoteCommunication *)arg; Error error; ConnectionFileDescriptor *connection = (ConnectionFileDescriptor *)comm->GetConnection (); if (connection) { // Do the listen on another thread so we can continue on... if (connection->Connect(comm->m_listen_url.c_str(), &error) != eConnectionStatusSuccess) comm->SetConnection(NULL); } return NULL; } Error GDBRemoteCommunication::StartDebugserverProcess (const char *url, Platform *platform, ProcessLaunchInfo &launch_info, uint16_t *port, const Args& inferior_args) { Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PROCESS)); if (log) log->Printf ("GDBRemoteCommunication::%s(url=%s, port=%" PRIu16, __FUNCTION__, url ? url : "", port ? *port : uint16_t(0)); Error error; // If we locate debugserver, keep that located version around static FileSpec g_debugserver_file_spec; char debugserver_path[PATH_MAX]; FileSpec &debugserver_file_spec = launch_info.GetExecutableFile(); // Always check to see if we have an environment override for the path // to the debugserver to use and use it if we do. const char *env_debugserver_path = getenv("LLDB_DEBUGSERVER_PATH"); if (env_debugserver_path) { debugserver_file_spec.SetFile (env_debugserver_path, false); if (log) log->Printf ("GDBRemoteCommunication::%s() gdb-remote stub exe path set from environment variable: %s", __FUNCTION__, env_debugserver_path); } else debugserver_file_spec = g_debugserver_file_spec; bool debugserver_exists = debugserver_file_spec.Exists(); if (!debugserver_exists) { // The debugserver binary is in the LLDB.framework/Resources // directory. if (HostInfo::GetLLDBPath(ePathTypeSupportExecutableDir, debugserver_file_spec)) { debugserver_file_spec.AppendPathComponent (DEBUGSERVER_BASENAME); debugserver_exists = debugserver_file_spec.Exists(); if (debugserver_exists) { if (log) log->Printf ("GDBRemoteCommunication::%s() found gdb-remote stub exe '%s'", __FUNCTION__, debugserver_file_spec.GetPath ().c_str ()); g_debugserver_file_spec = debugserver_file_spec; } else { debugserver_file_spec = platform->LocateExecutable(DEBUGSERVER_BASENAME); if (debugserver_file_spec) { // Platform::LocateExecutable() wouldn't return a path if it doesn't exist debugserver_exists = true; } else { if (log) log->Printf ("GDBRemoteCommunication::%s() could not find gdb-remote stub exe '%s'", __FUNCTION__, debugserver_file_spec.GetPath ().c_str ()); } // Don't cache the platform specific GDB server binary as it could change // from platform to platform g_debugserver_file_spec.Clear(); } } } if (debugserver_exists) { debugserver_file_spec.GetPath (debugserver_path, sizeof(debugserver_path)); Args &debugserver_args = launch_info.GetArguments(); debugserver_args.Clear(); char arg_cstr[PATH_MAX]; // Start args with "debugserver /file/path -r --" debugserver_args.AppendArgument(debugserver_path); #if !defined(__APPLE__) // First argument to lldb-server must be mode in which to run. debugserver_args.AppendArgument("gdbserver"); #endif // If a url is supplied then use it if (url) debugserver_args.AppendArgument(url); // use native registers, not the GDB registers debugserver_args.AppendArgument("--native-regs"); if (launch_info.GetLaunchInSeparateProcessGroup()) { debugserver_args.AppendArgument("--setsid"); } llvm::SmallString named_pipe_path; // socket_pipe is used by debug server to communicate back either // TCP port or domain socket name which it listens on. // The second purpose of the pipe to serve as a synchronization point - // once data is written to the pipe, debug server is up and running. Pipe socket_pipe; // port is null when debug server should listen on domain socket - // we're not interested in port value but rather waiting for debug server // to become available. if ((port != nullptr && *port == 0) || port == nullptr) { if (url) { // Create a temporary file to get the stdout/stderr and redirect the // output of the command into this file. We will later read this file // if all goes well and fill the data into "command_output_ptr" #if defined(__APPLE__) // Binding to port zero, we need to figure out what port it ends up // using using a named pipe... error = socket_pipe.CreateWithUniqueName("debugserver-named-pipe", false, named_pipe_path); if (error.Fail()) { if (log) log->Printf("GDBRemoteCommunication::%s() " "named pipe creation failed: %s", __FUNCTION__, error.AsCString()); return error; } debugserver_args.AppendArgument("--named-pipe"); debugserver_args.AppendArgument(named_pipe_path.c_str()); #else // Binding to port zero, we need to figure out what port it ends up // using using an unnamed pipe... error = socket_pipe.CreateNew(true); if (error.Fail()) { if (log) log->Printf("GDBRemoteCommunication::%s() " "unnamed pipe creation failed: %s", __FUNCTION__, error.AsCString()); return error; } int write_fd = socket_pipe.GetWriteFileDescriptor(); debugserver_args.AppendArgument("--pipe"); debugserver_args.AppendArgument(std::to_string(write_fd).c_str()); launch_info.AppendCloseFileAction(socket_pipe.GetReadFileDescriptor()); #endif } else { // No host and port given, so lets listen on our end and make the debugserver // connect to us.. error = StartListenThread ("127.0.0.1", 0); if (error.Fail()) { if (log) log->Printf ("GDBRemoteCommunication::%s() unable to start listen thread: %s", __FUNCTION__, error.AsCString()); return error; } ConnectionFileDescriptor *connection = (ConnectionFileDescriptor *)GetConnection (); // Wait for 10 seconds to resolve the bound port *port = connection->GetListeningPort(10); if (*port > 0) { char port_cstr[32]; snprintf(port_cstr, sizeof(port_cstr), "127.0.0.1:%i", *port); // Send the host and port down that debugserver and specify an option // so that it connects back to the port we are listening to in this process debugserver_args.AppendArgument("--reverse-connect"); debugserver_args.AppendArgument(port_cstr); } else { error.SetErrorString ("failed to bind to port 0 on 127.0.0.1"); if (log) log->Printf ("GDBRemoteCommunication::%s() failed: %s", __FUNCTION__, error.AsCString()); return error; } } } const char *env_debugserver_log_file = getenv("LLDB_DEBUGSERVER_LOG_FILE"); if (env_debugserver_log_file) { ::snprintf (arg_cstr, sizeof(arg_cstr), "--log-file=%s", env_debugserver_log_file); debugserver_args.AppendArgument(arg_cstr); } #if defined(__APPLE__) const char *env_debugserver_log_flags = getenv("LLDB_DEBUGSERVER_LOG_FLAGS"); if (env_debugserver_log_flags) { ::snprintf (arg_cstr, sizeof(arg_cstr), "--log-flags=%s", env_debugserver_log_flags); debugserver_args.AppendArgument(arg_cstr); } #else const char *env_debugserver_log_channels = getenv("LLDB_SERVER_LOG_CHANNELS"); if (env_debugserver_log_channels) { ::snprintf (arg_cstr, sizeof(arg_cstr), "--log-channels=%s", env_debugserver_log_channels); debugserver_args.AppendArgument(arg_cstr); } #endif // Add additional args, starting with LLDB_DEBUGSERVER_EXTRA_ARG_1 until an env var doesn't come back. uint32_t env_var_index = 1; bool has_env_var; do { char env_var_name[64]; snprintf (env_var_name, sizeof (env_var_name), "LLDB_DEBUGSERVER_EXTRA_ARG_%" PRIu32, env_var_index++); const char *extra_arg = getenv(env_var_name); has_env_var = extra_arg != nullptr; if (has_env_var) { debugserver_args.AppendArgument (extra_arg); if (log) log->Printf ("GDBRemoteCommunication::%s adding env var %s contents to stub command line (%s)", __FUNCTION__, env_var_name, extra_arg); } } while (has_env_var); if (inferior_args.GetArgumentCount() > 0) { debugserver_args.AppendArgument ("--"); debugserver_args.AppendArguments (inferior_args); } // Copy the current environment to the gdbserver/debugserver instance StringList env; if (Host::GetEnvironment(env)) { for (size_t i = 0; i < env.GetSize(); ++i) launch_info.GetEnvironmentEntries().AppendArgument(env[i].c_str()); } // Close STDIN, STDOUT and STDERR. launch_info.AppendCloseFileAction (STDIN_FILENO); launch_info.AppendCloseFileAction (STDOUT_FILENO); launch_info.AppendCloseFileAction (STDERR_FILENO); // Redirect STDIN, STDOUT and STDERR to "/dev/null". launch_info.AppendSuppressFileAction (STDIN_FILENO, true, false); launch_info.AppendSuppressFileAction (STDOUT_FILENO, false, true); launch_info.AppendSuppressFileAction (STDERR_FILENO, false, true); error = Host::LaunchProcess(launch_info); if (error.Success() && launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID) { if (named_pipe_path.size() > 0) { error = socket_pipe.OpenAsReader(named_pipe_path, false); if (error.Fail()) if (log) log->Printf("GDBRemoteCommunication::%s() " "failed to open named pipe %s for reading: %s", __FUNCTION__, named_pipe_path.c_str(), error.AsCString()); } if (socket_pipe.CanWrite()) socket_pipe.CloseWriteFileDescriptor(); if (socket_pipe.CanRead()) { char port_cstr[PATH_MAX] = {0}; port_cstr[0] = '\0'; size_t num_bytes = sizeof(port_cstr); // Read port from pipe with 10 second timeout. error = socket_pipe.ReadWithTimeout(port_cstr, num_bytes, std::chrono::seconds{10}, num_bytes); if (error.Success() && (port != nullptr)) { assert(num_bytes > 0 && port_cstr[num_bytes-1] == '\0'); *port = StringConvert::ToUInt32(port_cstr, 0); if (log) log->Printf("GDBRemoteCommunication::%s() " "debugserver listens %u port", __FUNCTION__, *port); } else { if (log) log->Printf("GDBRemoteCommunication::%s() " "failed to read a port value from pipe %s: %s", __FUNCTION__, named_pipe_path.c_str(), error.AsCString()); } socket_pipe.Close(); } if (named_pipe_path.size() > 0) { const auto err = socket_pipe.Delete(named_pipe_path); if (err.Fail()) { if (log) log->Printf ("GDBRemoteCommunication::%s failed to delete pipe %s: %s", __FUNCTION__, named_pipe_path.c_str(), err.AsCString()); } } // Make sure we actually connect with the debugserver... JoinListenThread(); } } else { error.SetErrorStringWithFormat ("unable to locate " DEBUGSERVER_BASENAME ); } if (error.Fail()) { if (log) log->Printf ("GDBRemoteCommunication::%s() failed: %s", __FUNCTION__, error.AsCString()); } return error; } void GDBRemoteCommunication::DumpHistory(Stream &strm) { m_history.Dump (strm); } GDBRemoteCommunication::ScopedTimeout::ScopedTimeout (GDBRemoteCommunication& gdb_comm, uint32_t timeout) : m_gdb_comm (gdb_comm) { m_saved_timeout = m_gdb_comm.SetPacketTimeout (timeout); } GDBRemoteCommunication::ScopedTimeout::~ScopedTimeout () { m_gdb_comm.SetPacketTimeout (m_saved_timeout); } // This function is called via the Communications class read thread when bytes become available // for this connection. This function will consume all incoming bytes and try to parse whole // packets as they become available. Full packets are placed in a queue, so that all packet // requests can simply pop from this queue. Async notification packets will be dispatched // immediately to the ProcessGDBRemote Async thread via an event. void GDBRemoteCommunication::AppendBytesToCache (const uint8_t * bytes, size_t len, bool broadcast, lldb::ConnectionStatus status) { StringExtractorGDBRemote packet; while (true) { PacketType type = CheckForPacket(bytes, len, packet); // scrub the data so we do not pass it back to CheckForPacket // on future passes of the loop bytes = nullptr; len = 0; // we may have received no packet so lets bail out if (type == PacketType::Invalid) break; if (type == PacketType::Standard) { // scope for the mutex { // lock down the packet queue Mutex::Locker locker(m_packet_queue_mutex); // push a new packet into the queue m_packet_queue.push(packet); // Signal condition variable that we have a packet m_condition_queue_not_empty.Signal(); } } if (type == PacketType::Notify) { // put this packet into an event const char *pdata = packet.GetStringRef().c_str(); // as the communication class, we are a broadcaster and the // async thread is tuned to listen to us BroadcastEvent( eBroadcastBitGdbReadThreadGotNotify, new EventDataBytes(pdata)); } } }