1 //===-- GDBRemoteCommunication.cpp ------------------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "GDBRemoteCommunication.h"
18 // Other libraries and framework includes
19 #include "lldb/Core/StreamFile.h"
20 #include "lldb/Host/ConnectionFileDescriptor.h"
21 #include "lldb/Host/Host.h"
22 #include "lldb/Host/HostInfo.h"
23 #include "lldb/Host/Pipe.h"
24 #include "lldb/Host/Socket.h"
25 #include "lldb/Host/StringConvert.h"
26 #include "lldb/Host/ThreadLauncher.h"
27 #include "lldb/Target/Platform.h"
28 #include "lldb/Target/Process.h"
29 #include "lldb/Utility/FileSpec.h"
30 #include "lldb/Utility/Log.h"
31 #include "lldb/Utility/RegularExpression.h"
32 #include "lldb/Utility/StreamString.h"
33 #include "llvm/ADT/SmallString.h"
34 #include "llvm/Support/ScopedPrinter.h"
37 #include "ProcessGDBRemoteLog.h"
39 #if defined(__APPLE__)
40 #define DEBUGSERVER_BASENAME "debugserver"
42 #define DEBUGSERVER_BASENAME "lldb-server"
45 #if defined(HAVE_LIBCOMPRESSION)
46 #include <compression.h>
49 #if defined(HAVE_LIBZ)
54 using namespace lldb_private;
55 using namespace lldb_private::process_gdb_remote;
57 GDBRemoteCommunication::History::History(uint32_t size)
58 : m_packets(), m_curr_idx(0), m_total_packet_count(0),
59 m_dumped_to_log(false) {
60 m_packets.resize(size);
63 GDBRemoteCommunication::History::~History() {}
65 void GDBRemoteCommunication::History::AddPacket(char packet_char,
67 uint32_t bytes_transmitted) {
68 const size_t size = m_packets.size();
70 const uint32_t idx = GetNextIndex();
71 m_packets[idx].packet.assign(1, packet_char);
72 m_packets[idx].type = type;
73 m_packets[idx].bytes_transmitted = bytes_transmitted;
74 m_packets[idx].packet_idx = m_total_packet_count;
75 m_packets[idx].tid = llvm::get_threadid();
79 void GDBRemoteCommunication::History::AddPacket(const std::string &src,
82 uint32_t bytes_transmitted) {
83 const size_t size = m_packets.size();
85 const uint32_t idx = GetNextIndex();
86 m_packets[idx].packet.assign(src, 0, src_len);
87 m_packets[idx].type = type;
88 m_packets[idx].bytes_transmitted = bytes_transmitted;
89 m_packets[idx].packet_idx = m_total_packet_count;
90 m_packets[idx].tid = llvm::get_threadid();
94 void GDBRemoteCommunication::History::Dump(Stream &strm) const {
95 const uint32_t size = GetNumPacketsInHistory();
96 const uint32_t first_idx = GetFirstSavedPacketIndex();
97 const uint32_t stop_idx = m_curr_idx + size;
98 for (uint32_t i = first_idx; i < stop_idx; ++i) {
99 const uint32_t idx = NormalizeIndex(i);
100 const Entry &entry = m_packets[idx];
101 if (entry.type == ePacketTypeInvalid || entry.packet.empty())
103 strm.Printf("history[%u] tid=0x%4.4" PRIx64 " <%4u> %s packet: %s\n",
104 entry.packet_idx, entry.tid, entry.bytes_transmitted,
105 (entry.type == ePacketTypeSend) ? "send" : "read",
106 entry.packet.c_str());
110 void GDBRemoteCommunication::History::Dump(Log *log) const {
111 if (log && !m_dumped_to_log) {
112 m_dumped_to_log = true;
113 const uint32_t size = GetNumPacketsInHistory();
114 const uint32_t first_idx = GetFirstSavedPacketIndex();
115 const uint32_t stop_idx = m_curr_idx + size;
116 for (uint32_t i = first_idx; i < stop_idx; ++i) {
117 const uint32_t idx = NormalizeIndex(i);
118 const Entry &entry = m_packets[idx];
119 if (entry.type == ePacketTypeInvalid || entry.packet.empty())
121 log->Printf("history[%u] tid=0x%4.4" PRIx64 " <%4u> %s packet: %s",
122 entry.packet_idx, entry.tid, entry.bytes_transmitted,
123 (entry.type == ePacketTypeSend) ? "send" : "read",
124 entry.packet.c_str());
129 //----------------------------------------------------------------------
130 // GDBRemoteCommunication constructor
131 //----------------------------------------------------------------------
132 GDBRemoteCommunication::GDBRemoteCommunication(const char *comm_name,
133 const char *listener_name)
134 : Communication(comm_name),
135 #ifdef LLDB_CONFIGURATION_DEBUG
136 m_packet_timeout(1000),
140 m_echo_number(0), m_supports_qEcho(eLazyBoolCalculate), m_history(512),
141 m_send_acks(true), m_compression_type(CompressionType::None),
145 //----------------------------------------------------------------------
147 //----------------------------------------------------------------------
148 GDBRemoteCommunication::~GDBRemoteCommunication() {
153 // Stop the communications read thread which is used to parse all
154 // incoming packets. This function will block until the read
156 if (m_read_thread_enabled)
160 char GDBRemoteCommunication::CalculcateChecksum(llvm::StringRef payload) {
163 for (char c : payload)
166 return checksum & 255;
169 size_t GDBRemoteCommunication::SendAck() {
170 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS));
171 ConnectionStatus status = eConnectionStatusSuccess;
173 const size_t bytes_written = Write(&ch, 1, status, NULL);
175 log->Printf("<%4" PRIu64 "> send packet: %c", (uint64_t)bytes_written, ch);
176 m_history.AddPacket(ch, History::ePacketTypeSend, bytes_written);
177 return bytes_written;
180 size_t GDBRemoteCommunication::SendNack() {
181 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS));
182 ConnectionStatus status = eConnectionStatusSuccess;
184 const size_t bytes_written = Write(&ch, 1, status, NULL);
186 log->Printf("<%4" PRIu64 "> send packet: %c", (uint64_t)bytes_written, ch);
187 m_history.AddPacket(ch, History::ePacketTypeSend, bytes_written);
188 return bytes_written;
191 GDBRemoteCommunication::PacketResult
192 GDBRemoteCommunication::SendPacketNoLock(llvm::StringRef payload) {
194 StreamString packet(0, 4, eByteOrderBig);
197 packet.Write(payload.data(), payload.size());
199 packet.PutHex8(CalculcateChecksum(payload));
201 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS));
202 ConnectionStatus status = eConnectionStatusSuccess;
203 // TODO: Don't shimmy through a std::string, just use StringRef.
204 std::string packet_str = packet.GetString();
205 const char *packet_data = packet_str.c_str();
206 const size_t packet_length = packet.GetSize();
207 size_t bytes_written = Write(packet_data, packet_length, status, NULL);
209 size_t binary_start_offset = 0;
210 if (strncmp(packet_data, "$vFile:pwrite:", strlen("$vFile:pwrite:")) ==
212 const char *first_comma = strchr(packet_data, ',');
214 const char *second_comma = strchr(first_comma + 1, ',');
216 binary_start_offset = second_comma - packet_data + 1;
220 // If logging was just enabled and we have history, then dump out what
221 // we have to the log so we get the historical context. The Dump() call
223 // logs all of the packet will set a boolean so that we don't dump this
226 if (!m_history.DidDumpToLog())
229 if (binary_start_offset) {
231 // Print non binary data header
232 strm.Printf("<%4" PRIu64 "> send packet: %.*s", (uint64_t)bytes_written,
233 (int)binary_start_offset, packet_data);
235 // Print binary data exactly as sent
236 for (p = (const uint8_t *)packet_data + binary_start_offset; *p != '#';
238 strm.Printf("\\x%2.2x", *p);
239 // Print the checksum
240 strm.Printf("%*s", (int)3, p);
241 log->PutString(strm.GetString());
243 log->Printf("<%4" PRIu64 "> send packet: %.*s", (uint64_t)bytes_written,
244 (int)packet_length, packet_data);
247 m_history.AddPacket(packet.GetString(), packet_length,
248 History::ePacketTypeSend, bytes_written);
250 if (bytes_written == packet_length) {
254 return PacketResult::Success;
257 log->Printf("error: failed to send packet: %.*s", (int)packet_length,
261 return PacketResult::ErrorSendFailed;
264 GDBRemoteCommunication::PacketResult GDBRemoteCommunication::GetAck() {
265 StringExtractorGDBRemote packet;
266 PacketResult result = ReadPacket(packet, GetPacketTimeout(), false);
267 if (result == PacketResult::Success) {
268 if (packet.GetResponseType() ==
269 StringExtractorGDBRemote::ResponseType::eAck)
270 return PacketResult::Success;
272 return PacketResult::ErrorSendAck;
277 GDBRemoteCommunication::PacketResult
278 GDBRemoteCommunication::ReadPacket(StringExtractorGDBRemote &response,
279 Timeout<std::micro> timeout,
280 bool sync_on_timeout) {
281 if (m_read_thread_enabled)
282 return PopPacketFromQueue(response, timeout);
284 return WaitForPacketNoLock(response, timeout, sync_on_timeout);
287 // This function is called when a packet is requested.
288 // A whole packet is popped from the packet queue and returned to the caller.
289 // Packets are placed into this queue from the communication read thread.
290 // See GDBRemoteCommunication::AppendBytesToCache.
291 GDBRemoteCommunication::PacketResult
292 GDBRemoteCommunication::PopPacketFromQueue(StringExtractorGDBRemote &response,
293 Timeout<std::micro> timeout) {
294 auto pred = [&] { return !m_packet_queue.empty() && IsConnected(); };
295 // lock down the packet queue
296 std::unique_lock<std::mutex> lock(m_packet_queue_mutex);
299 m_condition_queue_not_empty.wait(lock, pred);
301 if (!m_condition_queue_not_empty.wait_for(lock, *timeout, pred))
302 return PacketResult::ErrorReplyTimeout;
304 return PacketResult::ErrorDisconnected;
307 // get the front element of the queue
308 response = m_packet_queue.front();
310 // remove the front element
311 m_packet_queue.pop();
314 return PacketResult::Success;
317 GDBRemoteCommunication::PacketResult
318 GDBRemoteCommunication::WaitForPacketNoLock(StringExtractorGDBRemote &packet,
319 Timeout<std::micro> timeout,
320 bool sync_on_timeout) {
321 uint8_t buffer[8192];
324 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS));
326 // Check for a packet from our cache first without trying any reading...
327 if (CheckForPacket(NULL, 0, packet) != PacketType::Invalid)
328 return PacketResult::Success;
330 bool timed_out = false;
331 bool disconnected = false;
332 while (IsConnected() && !timed_out) {
333 lldb::ConnectionStatus status = eConnectionStatusNoConnection;
334 size_t bytes_read = Read(buffer, sizeof(buffer), timeout, status, &error);
337 "Read(buffer, sizeof(buffer), timeout = {0}, "
338 "status = {1}, error = {2}) => bytes_read = {3}",
339 timeout, Communication::ConnectionStatusAsCString(status), error,
342 if (bytes_read > 0) {
343 if (CheckForPacket(buffer, bytes_read, packet) != PacketType::Invalid)
344 return PacketResult::Success;
347 case eConnectionStatusTimedOut:
348 case eConnectionStatusInterrupted:
349 if (sync_on_timeout) {
350 //------------------------------------------------------------------
351 /// Sync the remote GDB server and make sure we get a response that
352 /// corresponds to what we send.
354 /// Sends a "qEcho" packet and makes sure it gets the exact packet
355 /// echoed back. If the qEcho packet isn't supported, we send a qC
356 /// packet and make sure we get a valid thread ID back. We use the
357 /// "qC" packet since its response if very unique: is responds with
358 /// "QC%x" where %x is the thread ID of the current thread. This
359 /// makes the response unique enough from other packet responses to
360 /// ensure we are back on track.
362 /// This packet is needed after we time out sending a packet so we
363 /// can ensure that we are getting the response for the packet we
364 /// are sending. There are no sequence IDs in the GDB remote
365 /// protocol (there used to be, but they are not supported anymore)
366 /// so if you timeout sending packet "abc", you might then send
367 /// packet "cde" and get the response for the previous "abc" packet.
368 /// Many responses are "OK" or "" (unsupported) or "EXX" (error) so
369 /// many responses for packets can look like responses for other
370 /// packets. So if we timeout, we need to ensure that we can get
371 /// back on track. If we can't get back on track, we must
373 //------------------------------------------------------------------
374 bool sync_success = false;
375 bool got_actual_response = false;
376 // We timed out, we need to sync back up with the
377 char echo_packet[32];
378 int echo_packet_len = 0;
379 RegularExpression response_regex;
381 if (m_supports_qEcho == eLazyBoolYes) {
382 echo_packet_len = ::snprintf(echo_packet, sizeof(echo_packet),
383 "qEcho:%u", ++m_echo_number);
384 std::string regex_str = "^";
385 regex_str += echo_packet;
387 response_regex.Compile(regex_str);
390 ::snprintf(echo_packet, sizeof(echo_packet), "qC");
391 response_regex.Compile(llvm::StringRef("^QC[0-9A-Fa-f]+$"));
394 PacketResult echo_packet_result =
395 SendPacketNoLock(llvm::StringRef(echo_packet, echo_packet_len));
396 if (echo_packet_result == PacketResult::Success) {
397 const uint32_t max_retries = 3;
398 uint32_t successful_responses = 0;
399 for (uint32_t i = 0; i < max_retries; ++i) {
400 StringExtractorGDBRemote echo_response;
402 WaitForPacketNoLock(echo_response, timeout, false);
403 if (echo_packet_result == PacketResult::Success) {
404 ++successful_responses;
405 if (response_regex.Execute(echo_response.GetStringRef())) {
408 } else if (successful_responses == 1) {
409 // We got something else back as the first successful
410 // response, it probably is
411 // the response to the packet we actually wanted, so copy it
413 // is the first success and continue to try to get the qEcho
415 packet = echo_response;
416 got_actual_response = true;
418 } else if (echo_packet_result == PacketResult::ErrorReplyTimeout)
419 continue; // Packet timed out, continue waiting for a response
421 break; // Something else went wrong getting the packet back, we
422 // failed and are done trying
426 // We weren't able to sync back up with the server, we must abort
428 // all responses might not be from the right packets...
430 // We timed out, but were able to recover
431 if (got_actual_response) {
432 // We initially timed out, but we did get a response that came in
433 // before the successful
434 // reply to our qEcho packet, so lets say everything is fine...
435 return PacketResult::Success;
444 case eConnectionStatusSuccess:
445 // printf ("status = success but error = %s\n",
446 // error.AsCString("<invalid>"));
449 case eConnectionStatusEndOfFile:
450 case eConnectionStatusNoConnection:
451 case eConnectionStatusLostConnection:
452 case eConnectionStatusError:
461 return PacketResult::ErrorDisconnected;
463 return PacketResult::ErrorReplyTimeout;
465 return PacketResult::ErrorReplyFailed;
468 bool GDBRemoteCommunication::DecompressPacket() {
469 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS));
471 if (!CompressionIsEnabled())
474 size_t pkt_size = m_bytes.size();
476 // Smallest possible compressed packet is $N#00 - an uncompressed empty reply,
477 // most commonly indicating
478 // an unsupported packet. Anything less than 5 characters, it's definitely
479 // not a compressed packet.
483 if (m_bytes[0] != '$' && m_bytes[0] != '%')
485 if (m_bytes[1] != 'C' && m_bytes[1] != 'N')
488 size_t hash_mark_idx = m_bytes.find('#');
489 if (hash_mark_idx == std::string::npos)
491 if (hash_mark_idx + 2 >= m_bytes.size())
494 if (!::isxdigit(m_bytes[hash_mark_idx + 1]) ||
495 !::isxdigit(m_bytes[hash_mark_idx + 2]))
498 size_t content_length =
500 5; // not counting '$', 'C' | 'N', '#', & the two hex checksum chars
501 size_t content_start = 2; // The first character of the
502 // compressed/not-compressed text of the packet
503 size_t checksum_idx =
505 1; // The first character of the two hex checksum characters
507 // Normally size_of_first_packet == m_bytes.size() but m_bytes may contain
509 // size_of_first_packet is the size of the initial packet which we'll replace
510 // with the decompressed
511 // version of, leaving the rest of m_bytes unmodified.
512 size_t size_of_first_packet = hash_mark_idx + 3;
514 // Compressed packets ("$C") start with a base10 number which is the size of
515 // the uncompressed payload,
516 // then a : and then the compressed data. e.g. $C1024:<binary>#00
517 // Update content_start and content_length to only include the <binary> part
520 uint64_t decompressed_bufsize = ULONG_MAX;
521 if (m_bytes[1] == 'C') {
522 size_t i = content_start;
523 while (i < hash_mark_idx && isdigit(m_bytes[i]))
525 if (i < hash_mark_idx && m_bytes[i] == ':') {
528 content_length = hash_mark_idx - content_start;
529 std::string bufsize_str(m_bytes.data() + 2, i - 2 - 1);
531 decompressed_bufsize = ::strtoul(bufsize_str.c_str(), NULL, 10);
532 if (errno != 0 || decompressed_bufsize == ULONG_MAX) {
533 m_bytes.erase(0, size_of_first_packet);
540 char packet_checksum_cstr[3];
541 packet_checksum_cstr[0] = m_bytes[checksum_idx];
542 packet_checksum_cstr[1] = m_bytes[checksum_idx + 1];
543 packet_checksum_cstr[2] = '\0';
544 long packet_checksum = strtol(packet_checksum_cstr, NULL, 16);
546 long actual_checksum = CalculcateChecksum(
547 llvm::StringRef(m_bytes).substr(1, hash_mark_idx - 1));
548 bool success = packet_checksum == actual_checksum;
552 "error: checksum mismatch: %.*s expected 0x%2.2x, got 0x%2.2x",
553 (int)(pkt_size), m_bytes.c_str(), (uint8_t)packet_checksum,
554 (uint8_t)actual_checksum);
556 // Send the ack or nack if needed
559 m_bytes.erase(0, size_of_first_packet);
566 if (m_bytes[1] == 'N') {
567 // This packet was not compressed -- delete the 'N' character at the
568 // start and the packet may be processed as-is.
573 // Reverse the gdb-remote binary escaping that was done to the compressed text
575 // guard characters like '$', '#', '}', etc.
576 std::vector<uint8_t> unescaped_content;
577 unescaped_content.reserve(content_length);
578 size_t i = content_start;
579 while (i < hash_mark_idx) {
580 if (m_bytes[i] == '}') {
582 unescaped_content.push_back(m_bytes[i] ^ 0x20);
584 unescaped_content.push_back(m_bytes[i]);
589 uint8_t *decompressed_buffer = nullptr;
590 size_t decompressed_bytes = 0;
592 if (decompressed_bufsize != ULONG_MAX) {
593 decompressed_buffer = (uint8_t *)malloc(decompressed_bufsize + 1);
594 if (decompressed_buffer == nullptr) {
595 m_bytes.erase(0, size_of_first_packet);
600 #if defined(HAVE_LIBCOMPRESSION)
601 // libcompression is weak linked so check that compression_decode_buffer() is
603 if (compression_decode_buffer != NULL &&
604 (m_compression_type == CompressionType::ZlibDeflate ||
605 m_compression_type == CompressionType::LZFSE ||
606 m_compression_type == CompressionType::LZ4)) {
607 compression_algorithm compression_type;
608 if (m_compression_type == CompressionType::LZFSE)
609 compression_type = COMPRESSION_LZFSE;
610 else if (m_compression_type == CompressionType::ZlibDeflate)
611 compression_type = COMPRESSION_ZLIB;
612 else if (m_compression_type == CompressionType::LZ4)
613 compression_type = COMPRESSION_LZ4_RAW;
614 else if (m_compression_type == CompressionType::LZMA)
615 compression_type = COMPRESSION_LZMA;
617 // If we have the expected size of the decompressed payload, we can allocate
618 // the right-sized buffer and do it. If we don't have that information,
620 // need to try decoding into a big buffer and if the buffer wasn't big
622 // increase it and try again.
624 if (decompressed_bufsize != ULONG_MAX && decompressed_buffer != nullptr) {
625 decompressed_bytes = compression_decode_buffer(
626 decompressed_buffer, decompressed_bufsize + 10,
627 (uint8_t *)unescaped_content.data(), unescaped_content.size(), NULL,
633 #if defined(HAVE_LIBZ)
634 if (decompressed_bytes == 0 && decompressed_bufsize != ULONG_MAX &&
635 decompressed_buffer != nullptr &&
636 m_compression_type == CompressionType::ZlibDeflate) {
638 memset(&stream, 0, sizeof(z_stream));
639 stream.next_in = (Bytef *)unescaped_content.data();
640 stream.avail_in = (uInt)unescaped_content.size();
642 stream.next_out = (Bytef *)decompressed_buffer;
643 stream.avail_out = decompressed_bufsize;
644 stream.total_out = 0;
645 stream.zalloc = Z_NULL;
646 stream.zfree = Z_NULL;
647 stream.opaque = Z_NULL;
649 if (inflateInit2(&stream, -15) == Z_OK) {
650 int status = inflate(&stream, Z_NO_FLUSH);
652 if (status == Z_STREAM_END) {
653 decompressed_bytes = stream.total_out;
659 if (decompressed_bytes == 0 || decompressed_buffer == nullptr) {
660 if (decompressed_buffer)
661 free(decompressed_buffer);
662 m_bytes.erase(0, size_of_first_packet);
666 std::string new_packet;
667 new_packet.reserve(decompressed_bytes + 6);
668 new_packet.push_back(m_bytes[0]);
669 new_packet.append((const char *)decompressed_buffer, decompressed_bytes);
670 new_packet.push_back('#');
672 uint8_t decompressed_checksum = CalculcateChecksum(
673 llvm::StringRef((const char *)decompressed_buffer, decompressed_bytes));
674 char decompressed_checksum_str[3];
675 snprintf(decompressed_checksum_str, 3, "%02x", decompressed_checksum);
676 new_packet.append(decompressed_checksum_str);
678 new_packet.push_back('0');
679 new_packet.push_back('0');
682 m_bytes.replace(0, size_of_first_packet, new_packet.data(),
685 free(decompressed_buffer);
689 GDBRemoteCommunication::PacketType
690 GDBRemoteCommunication::CheckForPacket(const uint8_t *src, size_t src_len,
691 StringExtractorGDBRemote &packet) {
692 // Put the packet data into the buffer in a thread safe fashion
693 std::lock_guard<std::recursive_mutex> guard(m_bytes_mutex);
695 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS));
697 if (src && src_len > 0) {
698 if (log && log->GetVerbose()) {
700 log->Printf("GDBRemoteCommunication::%s adding %u bytes: %.*s",
701 __FUNCTION__, (uint32_t)src_len, (uint32_t)src_len, src);
703 m_bytes.append((const char *)src, src_len);
706 bool isNotifyPacket = false;
708 // Parse up the packets into gdb remote packets
709 if (!m_bytes.empty()) {
710 // end_idx must be one past the last valid packet byte. Start
711 // it off with an invalid value that is the same as the current
713 size_t content_start = 0;
714 size_t content_length = 0;
715 size_t total_length = 0;
716 size_t checksum_idx = std::string::npos;
718 // Size of packet before it is decompressed, for logging purposes
719 size_t original_packet_size = m_bytes.size();
720 if (CompressionIsEnabled()) {
721 if (DecompressPacket() == false) {
723 return GDBRemoteCommunication::PacketType::Standard;
727 switch (m_bytes[0]) {
728 case '+': // Look for ack
729 case '-': // Look for cancel
730 case '\x03': // ^C to halt target
731 content_length = total_length = 1; // The command is one byte long...
734 case '%': // Async notify packet
735 isNotifyPacket = true;
739 // Look for a standard gdb packet?
741 size_t hash_pos = m_bytes.find('#');
742 if (hash_pos != std::string::npos) {
743 if (hash_pos + 2 < m_bytes.size()) {
744 checksum_idx = hash_pos + 1;
745 // Skip the dollar sign
747 // Don't include the # in the content or the $ in the content length
748 content_length = hash_pos - 1;
751 hash_pos + 3; // Skip the # and the two hex checksum bytes
753 // Checksum bytes aren't all here yet
754 content_length = std::string::npos;
761 // We have an unexpected byte and we need to flush all bad
762 // data that is in m_bytes, so we need to find the first
763 // byte that is a '+' (ACK), '-' (NACK), \x03 (CTRL+C interrupt),
764 // or '$' character (start of packet header) or of course,
765 // the end of the data in m_bytes...
766 const size_t bytes_len = m_bytes.size();
769 for (idx = 1; !done && idx < bytes_len; ++idx) {
770 switch (m_bytes[idx]) {
784 log->Printf("GDBRemoteCommunication::%s tossing %u junk bytes: '%.*s'",
785 __FUNCTION__, idx - 1, idx - 1, m_bytes.c_str());
786 m_bytes.erase(0, idx - 1);
790 if (content_length == std::string::npos) {
792 return GDBRemoteCommunication::PacketType::Invalid;
793 } else if (total_length > 0) {
795 // We have a valid packet...
796 assert(content_length <= m_bytes.size());
797 assert(total_length <= m_bytes.size());
798 assert(content_length <= total_length);
799 size_t content_end = content_start + content_length;
802 std::string &packet_str = packet.GetStringRef();
804 // If logging was just enabled and we have history, then dump out what
805 // we have to the log so we get the historical context. The Dump() call
807 // logs all of the packet will set a boolean so that we don't dump this
810 if (!m_history.DidDumpToLog())
814 // Only detect binary for packets that start with a '$' and have a '#CC'
816 if (m_bytes[0] == '$' && total_length > 4) {
817 for (size_t i = 0; !binary && i < total_length; ++i) {
818 if (isprint(m_bytes[i]) == 0 && isspace(m_bytes[i]) == 0) {
826 if (CompressionIsEnabled())
827 strm.Printf("<%4" PRIu64 ":%" PRIu64 "> read packet: %c",
828 (uint64_t)original_packet_size, (uint64_t)total_length,
831 strm.Printf("<%4" PRIu64 "> read packet: %c",
832 (uint64_t)total_length, m_bytes[0]);
833 for (size_t i = content_start; i < content_end; ++i) {
834 // Remove binary escaped bytes when displaying the packet...
835 const char ch = m_bytes[i];
837 // 0x7d is the escape character. The next character is to
838 // be XOR'd with 0x20.
839 const char escapee = m_bytes[++i] ^ 0x20;
840 strm.Printf("%2.2x", escapee);
842 strm.Printf("%2.2x", (uint8_t)ch);
846 strm.Printf("%c%c%c", m_bytes[total_length - 3],
847 m_bytes[total_length - 2], m_bytes[total_length - 1]);
848 log->PutString(strm.GetString());
850 if (CompressionIsEnabled())
851 log->Printf("<%4" PRIu64 ":%" PRIu64 "> read packet: %.*s",
852 (uint64_t)original_packet_size, (uint64_t)total_length,
853 (int)(total_length), m_bytes.c_str());
855 log->Printf("<%4" PRIu64 "> read packet: %.*s",
856 (uint64_t)total_length, (int)(total_length),
861 m_history.AddPacket(m_bytes, total_length, History::ePacketTypeRecv,
864 // Clear packet_str in case there is some existing data in it.
866 // Copy the packet from m_bytes to packet_str expanding the
867 // run-length encoding in the process.
868 // Reserve enough byte for the most common case (no RLE used)
869 packet_str.reserve(m_bytes.length());
870 for (std::string::const_iterator c = m_bytes.begin() + content_start;
871 c != m_bytes.begin() + content_end; ++c) {
873 // '*' indicates RLE. Next character will give us the
874 // repeat count and previous character is what is to be
876 char char_to_repeat = packet_str.back();
877 // Number of time the previous character is repeated
878 int repeat_count = *++c + 3 - ' ';
879 // We have the char_to_repeat and repeat_count. Now push
881 for (int i = 0; i < repeat_count; ++i)
882 packet_str.push_back(char_to_repeat);
883 } else if (*c == 0x7d) {
884 // 0x7d is the escape character. The next character is to
885 // be XOR'd with 0x20.
886 char escapee = *++c ^ 0x20;
887 packet_str.push_back(escapee);
889 packet_str.push_back(*c);
893 if (m_bytes[0] == '$' || m_bytes[0] == '%') {
894 assert(checksum_idx < m_bytes.size());
895 if (::isxdigit(m_bytes[checksum_idx + 0]) ||
896 ::isxdigit(m_bytes[checksum_idx + 1])) {
898 const char *packet_checksum_cstr = &m_bytes[checksum_idx];
899 char packet_checksum = strtol(packet_checksum_cstr, NULL, 16);
900 char actual_checksum = CalculcateChecksum(packet_str);
901 success = packet_checksum == actual_checksum;
904 log->Printf("error: checksum mismatch: %.*s expected 0x%2.2x, "
906 (int)(total_length), m_bytes.c_str(),
907 (uint8_t)packet_checksum, (uint8_t)actual_checksum);
909 // Send the ack or nack if needed
918 log->Printf("error: invalid checksum in packet: '%s'\n",
923 m_bytes.erase(0, total_length);
924 packet.SetFilePos(0);
927 return GDBRemoteCommunication::PacketType::Notify;
929 return GDBRemoteCommunication::PacketType::Standard;
933 return GDBRemoteCommunication::PacketType::Invalid;
936 Error GDBRemoteCommunication::StartListenThread(const char *hostname,
939 if (m_listen_thread.IsJoinable()) {
940 error.SetErrorString("listen thread already running");
942 char listen_url[512];
943 if (hostname && hostname[0])
944 snprintf(listen_url, sizeof(listen_url), "listen://%s:%i", hostname,
947 snprintf(listen_url, sizeof(listen_url), "listen://%i", port);
948 m_listen_url = listen_url;
949 SetConnection(new ConnectionFileDescriptor());
950 m_listen_thread = ThreadLauncher::LaunchThread(
951 listen_url, GDBRemoteCommunication::ListenThread, this, &error);
956 bool GDBRemoteCommunication::JoinListenThread() {
957 if (m_listen_thread.IsJoinable())
958 m_listen_thread.Join(nullptr);
962 lldb::thread_result_t
963 GDBRemoteCommunication::ListenThread(lldb::thread_arg_t arg) {
964 GDBRemoteCommunication *comm = (GDBRemoteCommunication *)arg;
966 ConnectionFileDescriptor *connection =
967 (ConnectionFileDescriptor *)comm->GetConnection();
970 // Do the listen on another thread so we can continue on...
971 if (connection->Connect(comm->m_listen_url.c_str(), &error) !=
972 eConnectionStatusSuccess)
973 comm->SetConnection(NULL);
978 Error GDBRemoteCommunication::StartDebugserverProcess(
979 const char *url, Platform *platform, ProcessLaunchInfo &launch_info,
980 uint16_t *port, const Args *inferior_args, int pass_comm_fd) {
981 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PROCESS));
983 log->Printf("GDBRemoteCommunication::%s(url=%s, port=%" PRIu16 ")",
984 __FUNCTION__, url ? url : "<empty>",
985 port ? *port : uint16_t(0));
988 // If we locate debugserver, keep that located version around
989 static FileSpec g_debugserver_file_spec;
991 char debugserver_path[PATH_MAX];
992 FileSpec &debugserver_file_spec = launch_info.GetExecutableFile();
994 // Always check to see if we have an environment override for the path
995 // to the debugserver to use and use it if we do.
996 const char *env_debugserver_path = getenv("LLDB_DEBUGSERVER_PATH");
997 if (env_debugserver_path) {
998 debugserver_file_spec.SetFile(env_debugserver_path, false);
1000 log->Printf("GDBRemoteCommunication::%s() gdb-remote stub exe path set "
1001 "from environment variable: %s",
1002 __FUNCTION__, env_debugserver_path);
1004 debugserver_file_spec = g_debugserver_file_spec;
1005 bool debugserver_exists = debugserver_file_spec.Exists();
1006 if (!debugserver_exists) {
1007 // The debugserver binary is in the LLDB.framework/Resources
1009 if (HostInfo::GetLLDBPath(ePathTypeSupportExecutableDir,
1010 debugserver_file_spec)) {
1011 debugserver_file_spec.AppendPathComponent(DEBUGSERVER_BASENAME);
1012 debugserver_exists = debugserver_file_spec.Exists();
1013 if (debugserver_exists) {
1016 "GDBRemoteCommunication::%s() found gdb-remote stub exe '%s'",
1017 __FUNCTION__, debugserver_file_spec.GetPath().c_str());
1019 g_debugserver_file_spec = debugserver_file_spec;
1021 debugserver_file_spec =
1022 platform->LocateExecutable(DEBUGSERVER_BASENAME);
1023 if (debugserver_file_spec) {
1024 // Platform::LocateExecutable() wouldn't return a path if it doesn't
1026 debugserver_exists = true;
1029 log->Printf("GDBRemoteCommunication::%s() could not find "
1030 "gdb-remote stub exe '%s'",
1031 __FUNCTION__, debugserver_file_spec.GetPath().c_str());
1033 // Don't cache the platform specific GDB server binary as it could
1035 // from platform to platform
1036 g_debugserver_file_spec.Clear();
1041 if (debugserver_exists) {
1042 debugserver_file_spec.GetPath(debugserver_path, sizeof(debugserver_path));
1044 Args &debugserver_args = launch_info.GetArguments();
1045 debugserver_args.Clear();
1046 char arg_cstr[PATH_MAX];
1048 // Start args with "debugserver /file/path -r --"
1049 debugserver_args.AppendArgument(llvm::StringRef(debugserver_path));
1051 #if !defined(__APPLE__)
1052 // First argument to lldb-server must be mode in which to run.
1053 debugserver_args.AppendArgument(llvm::StringRef("gdbserver"));
1056 // If a url is supplied then use it
1058 debugserver_args.AppendArgument(llvm::StringRef(url));
1060 if (pass_comm_fd >= 0) {
1061 StreamString fd_arg;
1062 fd_arg.Printf("--fd=%i", pass_comm_fd);
1063 debugserver_args.AppendArgument(fd_arg.GetString());
1064 // Send "pass_comm_fd" down to the inferior so it can use it to
1065 // communicate back with this process
1066 launch_info.AppendDuplicateFileAction(pass_comm_fd, pass_comm_fd);
1069 // use native registers, not the GDB registers
1070 debugserver_args.AppendArgument(llvm::StringRef("--native-regs"));
1072 if (launch_info.GetLaunchInSeparateProcessGroup()) {
1073 debugserver_args.AppendArgument(llvm::StringRef("--setsid"));
1076 llvm::SmallString<PATH_MAX> named_pipe_path;
1077 // socket_pipe is used by debug server to communicate back either
1078 // TCP port or domain socket name which it listens on.
1079 // The second purpose of the pipe to serve as a synchronization point -
1080 // once data is written to the pipe, debug server is up and running.
1083 // port is null when debug server should listen on domain socket -
1084 // we're not interested in port value but rather waiting for debug server
1085 // to become available.
1086 if (pass_comm_fd == -1) {
1088 // Create a temporary file to get the stdout/stderr and redirect the
1089 // output of the command into this file. We will later read this file
1090 // if all goes well and fill the data into "command_output_ptr"
1091 #if defined(__APPLE__)
1092 // Binding to port zero, we need to figure out what port it ends up
1093 // using using a named pipe...
1094 error = socket_pipe.CreateWithUniqueName("debugserver-named-pipe",
1095 false, named_pipe_path);
1098 log->Printf("GDBRemoteCommunication::%s() "
1099 "named pipe creation failed: %s",
1100 __FUNCTION__, error.AsCString());
1103 debugserver_args.AppendArgument(llvm::StringRef("--named-pipe"));
1104 debugserver_args.AppendArgument(named_pipe_path);
1106 // Binding to port zero, we need to figure out what port it ends up
1107 // using using an unnamed pipe...
1108 error = socket_pipe.CreateNew(true);
1111 log->Printf("GDBRemoteCommunication::%s() "
1112 "unnamed pipe creation failed: %s",
1113 __FUNCTION__, error.AsCString());
1116 int write_fd = socket_pipe.GetWriteFileDescriptor();
1117 debugserver_args.AppendArgument(llvm::StringRef("--pipe"));
1118 debugserver_args.AppendArgument(llvm::to_string(write_fd));
1119 launch_info.AppendCloseFileAction(socket_pipe.GetReadFileDescriptor());
1122 // No host and port given, so lets listen on our end and make the
1125 error = StartListenThread("127.0.0.1", 0);
1128 log->Printf("GDBRemoteCommunication::%s() unable to start listen "
1130 __FUNCTION__, error.AsCString());
1134 ConnectionFileDescriptor *connection =
1135 (ConnectionFileDescriptor *)GetConnection();
1136 // Wait for 10 seconds to resolve the bound port
1137 uint16_t port_ = connection->GetListeningPort(10);
1140 snprintf(port_cstr, sizeof(port_cstr), "127.0.0.1:%i", port_);
1141 // Send the host and port down that debugserver and specify an option
1142 // so that it connects back to the port we are listening to in this
1144 debugserver_args.AppendArgument(llvm::StringRef("--reverse-connect"));
1145 debugserver_args.AppendArgument(llvm::StringRef(port_cstr));
1149 error.SetErrorString("failed to bind to port 0 on 127.0.0.1");
1151 log->Printf("GDBRemoteCommunication::%s() failed: %s", __FUNCTION__,
1158 const char *env_debugserver_log_file = getenv("LLDB_DEBUGSERVER_LOG_FILE");
1159 if (env_debugserver_log_file) {
1160 ::snprintf(arg_cstr, sizeof(arg_cstr), "--log-file=%s",
1161 env_debugserver_log_file);
1162 debugserver_args.AppendArgument(llvm::StringRef(arg_cstr));
1165 #if defined(__APPLE__)
1166 const char *env_debugserver_log_flags =
1167 getenv("LLDB_DEBUGSERVER_LOG_FLAGS");
1168 if (env_debugserver_log_flags) {
1169 ::snprintf(arg_cstr, sizeof(arg_cstr), "--log-flags=%s",
1170 env_debugserver_log_flags);
1171 debugserver_args.AppendArgument(llvm::StringRef(arg_cstr));
1174 const char *env_debugserver_log_channels =
1175 getenv("LLDB_SERVER_LOG_CHANNELS");
1176 if (env_debugserver_log_channels) {
1177 ::snprintf(arg_cstr, sizeof(arg_cstr), "--log-channels=%s",
1178 env_debugserver_log_channels);
1179 debugserver_args.AppendArgument(llvm::StringRef(arg_cstr));
1183 // Add additional args, starting with LLDB_DEBUGSERVER_EXTRA_ARG_1 until an
1184 // env var doesn't come back.
1185 uint32_t env_var_index = 1;
1188 char env_var_name[64];
1189 snprintf(env_var_name, sizeof(env_var_name),
1190 "LLDB_DEBUGSERVER_EXTRA_ARG_%" PRIu32, env_var_index++);
1191 const char *extra_arg = getenv(env_var_name);
1192 has_env_var = extra_arg != nullptr;
1195 debugserver_args.AppendArgument(llvm::StringRef(extra_arg));
1197 log->Printf("GDBRemoteCommunication::%s adding env var %s contents "
1198 "to stub command line (%s)",
1199 __FUNCTION__, env_var_name, extra_arg);
1201 } while (has_env_var);
1203 if (inferior_args && inferior_args->GetArgumentCount() > 0) {
1204 debugserver_args.AppendArgument(llvm::StringRef("--"));
1205 debugserver_args.AppendArguments(*inferior_args);
1208 // Copy the current environment to the gdbserver/debugserver instance
1210 if (Host::GetEnvironment(env)) {
1211 for (size_t i = 0; i < env.GetSize(); ++i)
1212 launch_info.GetEnvironmentEntries().AppendArgument(env[i]);
1215 // Close STDIN, STDOUT and STDERR.
1216 launch_info.AppendCloseFileAction(STDIN_FILENO);
1217 launch_info.AppendCloseFileAction(STDOUT_FILENO);
1218 launch_info.AppendCloseFileAction(STDERR_FILENO);
1220 // Redirect STDIN, STDOUT and STDERR to "/dev/null".
1221 launch_info.AppendSuppressFileAction(STDIN_FILENO, true, false);
1222 launch_info.AppendSuppressFileAction(STDOUT_FILENO, false, true);
1223 launch_info.AppendSuppressFileAction(STDERR_FILENO, false, true);
1226 StreamString string_stream;
1227 Platform *const platform = nullptr;
1228 launch_info.Dump(string_stream, platform);
1229 log->Printf("launch info for gdb-remote stub:\n%s",
1230 string_stream.GetData());
1232 error = Host::LaunchProcess(launch_info);
1234 if (error.Success() &&
1235 (launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID) &&
1236 pass_comm_fd == -1) {
1237 if (named_pipe_path.size() > 0) {
1238 error = socket_pipe.OpenAsReader(named_pipe_path, false);
1241 log->Printf("GDBRemoteCommunication::%s() "
1242 "failed to open named pipe %s for reading: %s",
1243 __FUNCTION__, named_pipe_path.c_str(),
1247 if (socket_pipe.CanWrite())
1248 socket_pipe.CloseWriteFileDescriptor();
1249 if (socket_pipe.CanRead()) {
1250 char port_cstr[PATH_MAX] = {0};
1251 port_cstr[0] = '\0';
1252 size_t num_bytes = sizeof(port_cstr);
1253 // Read port from pipe with 10 second timeout.
1254 error = socket_pipe.ReadWithTimeout(
1255 port_cstr, num_bytes, std::chrono::seconds{10}, num_bytes);
1256 if (error.Success() && (port != nullptr)) {
1257 assert(num_bytes > 0 && port_cstr[num_bytes - 1] == '\0');
1258 uint16_t child_port = StringConvert::ToUInt32(port_cstr, 0);
1259 if (*port == 0 || *port == child_port) {
1262 log->Printf("GDBRemoteCommunication::%s() "
1263 "debugserver listens %u port",
1264 __FUNCTION__, *port);
1267 log->Printf("GDBRemoteCommunication::%s() "
1268 "debugserver listening on port "
1269 "%d but requested port was %d",
1270 __FUNCTION__, (uint32_t)child_port,
1275 log->Printf("GDBRemoteCommunication::%s() "
1276 "failed to read a port value from pipe %s: %s",
1277 __FUNCTION__, named_pipe_path.c_str(),
1280 socket_pipe.Close();
1283 if (named_pipe_path.size() > 0) {
1284 const auto err = socket_pipe.Delete(named_pipe_path);
1288 "GDBRemoteCommunication::%s failed to delete pipe %s: %s",
1289 __FUNCTION__, named_pipe_path.c_str(), err.AsCString());
1293 // Make sure we actually connect with the debugserver...
1297 error.SetErrorStringWithFormat("unable to locate " DEBUGSERVER_BASENAME);
1302 log->Printf("GDBRemoteCommunication::%s() failed: %s", __FUNCTION__,
1309 void GDBRemoteCommunication::DumpHistory(Stream &strm) { m_history.Dump(strm); }
1311 GDBRemoteCommunication::ScopedTimeout::ScopedTimeout(
1312 GDBRemoteCommunication &gdb_comm, std::chrono::seconds timeout)
1313 : m_gdb_comm(gdb_comm), m_timeout_modified(false) {
1314 auto curr_timeout = gdb_comm.GetPacketTimeout();
1315 // Only update the timeout if the timeout is greater than the current
1316 // timeout. If the current timeout is larger, then just use that.
1317 if (curr_timeout < timeout) {
1318 m_timeout_modified = true;
1319 m_saved_timeout = m_gdb_comm.SetPacketTimeout(timeout);
1323 GDBRemoteCommunication::ScopedTimeout::~ScopedTimeout() {
1324 // Only restore the timeout if we set it in the constructor.
1325 if (m_timeout_modified)
1326 m_gdb_comm.SetPacketTimeout(m_saved_timeout);
1329 // This function is called via the Communications class read thread when bytes
1331 // for this connection. This function will consume all incoming bytes and try to
1333 // packets as they become available. Full packets are placed in a queue, so that
1335 // requests can simply pop from this queue. Async notification packets will be
1337 // immediately to the ProcessGDBRemote Async thread via an event.
1338 void GDBRemoteCommunication::AppendBytesToCache(const uint8_t *bytes,
1339 size_t len, bool broadcast,
1340 lldb::ConnectionStatus status) {
1341 StringExtractorGDBRemote packet;
1344 PacketType type = CheckForPacket(bytes, len, packet);
1346 // scrub the data so we do not pass it back to CheckForPacket
1347 // on future passes of the loop
1351 // we may have received no packet so lets bail out
1352 if (type == PacketType::Invalid)
1355 if (type == PacketType::Standard) {
1356 // scope for the mutex
1358 // lock down the packet queue
1359 std::lock_guard<std::mutex> guard(m_packet_queue_mutex);
1360 // push a new packet into the queue
1361 m_packet_queue.push(packet);
1362 // Signal condition variable that we have a packet
1363 m_condition_queue_not_empty.notify_one();
1367 if (type == PacketType::Notify) {
1368 // put this packet into an event
1369 const char *pdata = packet.GetStringRef().c_str();
1371 // as the communication class, we are a broadcaster and the
1372 // async thread is tuned to listen to us
1373 BroadcastEvent(eBroadcastBitGdbReadThreadGotNotify,
1374 new EventDataBytes(pdata));