1 //===-- GDBRemoteCommunication.cpp ----------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "GDBRemoteCommunication.h" 10 11 #include <future> 12 #include <limits.h> 13 #include <string.h> 14 #include <sys/stat.h> 15 16 #include "lldb/Core/StreamFile.h" 17 #include "lldb/Host/Config.h" 18 #include "lldb/Host/ConnectionFileDescriptor.h" 19 #include "lldb/Host/FileSystem.h" 20 #include "lldb/Host/Host.h" 21 #include "lldb/Host/HostInfo.h" 22 #include "lldb/Host/Pipe.h" 23 #include "lldb/Host/ProcessLaunchInfo.h" 24 #include "lldb/Host/Socket.h" 25 #include "lldb/Host/StringConvert.h" 26 #include "lldb/Host/ThreadLauncher.h" 27 #include "lldb/Host/common/TCPSocket.h" 28 #include "lldb/Host/posix/ConnectionFileDescriptorPosix.h" 29 #include "lldb/Target/Platform.h" 30 #include "lldb/Utility/Event.h" 31 #include "lldb/Utility/FileSpec.h" 32 #include "lldb/Utility/Log.h" 33 #include "lldb/Utility/RegularExpression.h" 34 #include "lldb/Utility/Reproducer.h" 35 #include "lldb/Utility/StreamString.h" 36 #include "llvm/ADT/SmallString.h" 37 #include "llvm/Support/ScopedPrinter.h" 38 39 #include "ProcessGDBRemoteLog.h" 40 41 #if defined(__APPLE__) 42 #define DEBUGSERVER_BASENAME "debugserver" 43 #elif defined(_WIN32) 44 #define DEBUGSERVER_BASENAME "lldb-server.exe" 45 #else 46 #define DEBUGSERVER_BASENAME "lldb-server" 47 #endif 48 49 #if defined(HAVE_LIBCOMPRESSION) 50 #include <compression.h> 51 #endif 52 53 #if defined(HAVE_LIBZ) 54 #include <zlib.h> 55 #endif 56 57 using namespace lldb; 58 using namespace lldb_private; 59 using namespace lldb_private::process_gdb_remote; 60 61 // GDBRemoteCommunication constructor 62 GDBRemoteCommunication::GDBRemoteCommunication(const char *comm_name, 63 const char *listener_name) 64 : Communication(comm_name), 65 #ifdef LLDB_CONFIGURATION_DEBUG 66 m_packet_timeout(1000), 67 #else 68 m_packet_timeout(1), 69 #endif 70 m_echo_number(0), m_supports_qEcho(eLazyBoolCalculate), m_history(512), 71 m_send_acks(true), m_compression_type(CompressionType::None), 72 m_listen_url() { 73 } 74 75 // Destructor 76 GDBRemoteCommunication::~GDBRemoteCommunication() { 77 if (IsConnected()) { 78 Disconnect(); 79 } 80 81 #if defined(HAVE_LIBCOMPRESSION) 82 if (m_decompression_scratch) 83 free (m_decompression_scratch); 84 #endif 85 86 // Stop the communications read thread which is used to parse all incoming 87 // packets. This function will block until the read thread returns. 88 if (m_read_thread_enabled) 89 StopReadThread(); 90 } 91 92 char GDBRemoteCommunication::CalculcateChecksum(llvm::StringRef payload) { 93 int checksum = 0; 94 95 for (char c : payload) 96 checksum += c; 97 98 return checksum & 255; 99 } 100 101 size_t GDBRemoteCommunication::SendAck() { 102 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS)); 103 ConnectionStatus status = eConnectionStatusSuccess; 104 char ch = '+'; 105 const size_t bytes_written = Write(&ch, 1, status, nullptr); 106 LLDB_LOGF(log, "<%4" PRIu64 "> send packet: %c", (uint64_t)bytes_written, ch); 107 m_history.AddPacket(ch, GDBRemotePacket::ePacketTypeSend, bytes_written); 108 return bytes_written; 109 } 110 111 size_t GDBRemoteCommunication::SendNack() { 112 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS)); 113 ConnectionStatus status = eConnectionStatusSuccess; 114 char ch = '-'; 115 const size_t bytes_written = Write(&ch, 1, status, nullptr); 116 LLDB_LOGF(log, "<%4" PRIu64 "> send packet: %c", (uint64_t)bytes_written, ch); 117 m_history.AddPacket(ch, GDBRemotePacket::ePacketTypeSend, bytes_written); 118 return bytes_written; 119 } 120 121 GDBRemoteCommunication::PacketResult 122 GDBRemoteCommunication::SendPacketNoLock(llvm::StringRef payload) { 123 StreamString packet(0, 4, eByteOrderBig); 124 packet.PutChar('$'); 125 packet.Write(payload.data(), payload.size()); 126 packet.PutChar('#'); 127 packet.PutHex8(CalculcateChecksum(payload)); 128 std::string packet_str = std::string(packet.GetString()); 129 130 return SendRawPacketNoLock(packet_str); 131 } 132 133 GDBRemoteCommunication::PacketResult 134 GDBRemoteCommunication::SendRawPacketNoLock(llvm::StringRef packet, 135 bool skip_ack) { 136 if (IsConnected()) { 137 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS)); 138 ConnectionStatus status = eConnectionStatusSuccess; 139 const char *packet_data = packet.data(); 140 const size_t packet_length = packet.size(); 141 size_t bytes_written = Write(packet_data, packet_length, status, nullptr); 142 if (log) { 143 size_t binary_start_offset = 0; 144 if (strncmp(packet_data, "$vFile:pwrite:", strlen("$vFile:pwrite:")) == 145 0) { 146 const char *first_comma = strchr(packet_data, ','); 147 if (first_comma) { 148 const char *second_comma = strchr(first_comma + 1, ','); 149 if (second_comma) 150 binary_start_offset = second_comma - packet_data + 1; 151 } 152 } 153 154 // If logging was just enabled and we have history, then dump out what we 155 // have to the log so we get the historical context. The Dump() call that 156 // logs all of the packet will set a boolean so that we don't dump this 157 // more than once 158 if (!m_history.DidDumpToLog()) 159 m_history.Dump(log); 160 161 if (binary_start_offset) { 162 StreamString strm; 163 // Print non binary data header 164 strm.Printf("<%4" PRIu64 "> send packet: %.*s", (uint64_t)bytes_written, 165 (int)binary_start_offset, packet_data); 166 const uint8_t *p; 167 // Print binary data exactly as sent 168 for (p = (const uint8_t *)packet_data + binary_start_offset; *p != '#'; 169 ++p) 170 strm.Printf("\\x%2.2x", *p); 171 // Print the checksum 172 strm.Printf("%*s", (int)3, p); 173 log->PutString(strm.GetString()); 174 } else 175 LLDB_LOGF(log, "<%4" PRIu64 "> send packet: %.*s", 176 (uint64_t)bytes_written, (int)packet_length, packet_data); 177 } 178 179 m_history.AddPacket(packet.str(), packet_length, 180 GDBRemotePacket::ePacketTypeSend, bytes_written); 181 182 if (bytes_written == packet_length) { 183 if (!skip_ack && GetSendAcks()) 184 return GetAck(); 185 else 186 return PacketResult::Success; 187 } else { 188 LLDB_LOGF(log, "error: failed to send packet: %.*s", (int)packet_length, 189 packet_data); 190 } 191 } 192 return PacketResult::ErrorSendFailed; 193 } 194 195 GDBRemoteCommunication::PacketResult GDBRemoteCommunication::GetAck() { 196 StringExtractorGDBRemote packet; 197 PacketResult result = ReadPacket(packet, GetPacketTimeout(), false); 198 if (result == PacketResult::Success) { 199 if (packet.GetResponseType() == 200 StringExtractorGDBRemote::ResponseType::eAck) 201 return PacketResult::Success; 202 else 203 return PacketResult::ErrorSendAck; 204 } 205 return result; 206 } 207 208 GDBRemoteCommunication::PacketResult 209 GDBRemoteCommunication::ReadPacketWithOutputSupport( 210 StringExtractorGDBRemote &response, Timeout<std::micro> timeout, 211 bool sync_on_timeout, 212 llvm::function_ref<void(llvm::StringRef)> output_callback) { 213 auto result = ReadPacket(response, timeout, sync_on_timeout); 214 while (result == PacketResult::Success && response.IsNormalResponse() && 215 response.PeekChar() == 'O') { 216 response.GetChar(); 217 std::string output; 218 if (response.GetHexByteString(output)) 219 output_callback(output); 220 result = ReadPacket(response, timeout, sync_on_timeout); 221 } 222 return result; 223 } 224 225 GDBRemoteCommunication::PacketResult 226 GDBRemoteCommunication::ReadPacket(StringExtractorGDBRemote &response, 227 Timeout<std::micro> timeout, 228 bool sync_on_timeout) { 229 if (m_read_thread_enabled) 230 return PopPacketFromQueue(response, timeout); 231 else 232 return WaitForPacketNoLock(response, timeout, sync_on_timeout); 233 } 234 235 // This function is called when a packet is requested. 236 // A whole packet is popped from the packet queue and returned to the caller. 237 // Packets are placed into this queue from the communication read thread. See 238 // GDBRemoteCommunication::AppendBytesToCache. 239 GDBRemoteCommunication::PacketResult 240 GDBRemoteCommunication::PopPacketFromQueue(StringExtractorGDBRemote &response, 241 Timeout<std::micro> timeout) { 242 auto pred = [&] { return !m_packet_queue.empty() && IsConnected(); }; 243 // lock down the packet queue 244 std::unique_lock<std::mutex> lock(m_packet_queue_mutex); 245 246 if (!timeout) 247 m_condition_queue_not_empty.wait(lock, pred); 248 else { 249 if (!m_condition_queue_not_empty.wait_for(lock, *timeout, pred)) 250 return PacketResult::ErrorReplyTimeout; 251 if (!IsConnected()) 252 return PacketResult::ErrorDisconnected; 253 } 254 255 // get the front element of the queue 256 response = m_packet_queue.front(); 257 258 // remove the front element 259 m_packet_queue.pop(); 260 261 // we got a packet 262 return PacketResult::Success; 263 } 264 265 GDBRemoteCommunication::PacketResult 266 GDBRemoteCommunication::WaitForPacketNoLock(StringExtractorGDBRemote &packet, 267 Timeout<std::micro> timeout, 268 bool sync_on_timeout) { 269 uint8_t buffer[8192]; 270 Status error; 271 272 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS)); 273 274 // Check for a packet from our cache first without trying any reading... 275 if (CheckForPacket(nullptr, 0, packet) != PacketType::Invalid) 276 return PacketResult::Success; 277 278 bool timed_out = false; 279 bool disconnected = false; 280 while (IsConnected() && !timed_out) { 281 lldb::ConnectionStatus status = eConnectionStatusNoConnection; 282 size_t bytes_read = Read(buffer, sizeof(buffer), timeout, status, &error); 283 284 LLDB_LOGV(log, 285 "Read(buffer, sizeof(buffer), timeout = {0}, " 286 "status = {1}, error = {2}) => bytes_read = {3}", 287 timeout, Communication::ConnectionStatusAsCString(status), error, 288 bytes_read); 289 290 if (bytes_read > 0) { 291 if (CheckForPacket(buffer, bytes_read, packet) != PacketType::Invalid) 292 return PacketResult::Success; 293 } else { 294 switch (status) { 295 case eConnectionStatusTimedOut: 296 case eConnectionStatusInterrupted: 297 if (sync_on_timeout) { 298 /// Sync the remote GDB server and make sure we get a response that 299 /// corresponds to what we send. 300 /// 301 /// Sends a "qEcho" packet and makes sure it gets the exact packet 302 /// echoed back. If the qEcho packet isn't supported, we send a qC 303 /// packet and make sure we get a valid thread ID back. We use the 304 /// "qC" packet since its response if very unique: is responds with 305 /// "QC%x" where %x is the thread ID of the current thread. This 306 /// makes the response unique enough from other packet responses to 307 /// ensure we are back on track. 308 /// 309 /// This packet is needed after we time out sending a packet so we 310 /// can ensure that we are getting the response for the packet we 311 /// are sending. There are no sequence IDs in the GDB remote 312 /// protocol (there used to be, but they are not supported anymore) 313 /// so if you timeout sending packet "abc", you might then send 314 /// packet "cde" and get the response for the previous "abc" packet. 315 /// Many responses are "OK" or "" (unsupported) or "EXX" (error) so 316 /// many responses for packets can look like responses for other 317 /// packets. So if we timeout, we need to ensure that we can get 318 /// back on track. If we can't get back on track, we must 319 /// disconnect. 320 bool sync_success = false; 321 bool got_actual_response = false; 322 // We timed out, we need to sync back up with the 323 char echo_packet[32]; 324 int echo_packet_len = 0; 325 RegularExpression response_regex; 326 327 if (m_supports_qEcho == eLazyBoolYes) { 328 echo_packet_len = ::snprintf(echo_packet, sizeof(echo_packet), 329 "qEcho:%u", ++m_echo_number); 330 std::string regex_str = "^"; 331 regex_str += echo_packet; 332 regex_str += "$"; 333 response_regex = RegularExpression(regex_str); 334 } else { 335 echo_packet_len = 336 ::snprintf(echo_packet, sizeof(echo_packet), "qC"); 337 response_regex = 338 RegularExpression(llvm::StringRef("^QC[0-9A-Fa-f]+$")); 339 } 340 341 PacketResult echo_packet_result = 342 SendPacketNoLock(llvm::StringRef(echo_packet, echo_packet_len)); 343 if (echo_packet_result == PacketResult::Success) { 344 const uint32_t max_retries = 3; 345 uint32_t successful_responses = 0; 346 for (uint32_t i = 0; i < max_retries; ++i) { 347 StringExtractorGDBRemote echo_response; 348 echo_packet_result = 349 WaitForPacketNoLock(echo_response, timeout, false); 350 if (echo_packet_result == PacketResult::Success) { 351 ++successful_responses; 352 if (response_regex.Execute(echo_response.GetStringRef())) { 353 sync_success = true; 354 break; 355 } else if (successful_responses == 1) { 356 // We got something else back as the first successful 357 // response, it probably is the response to the packet we 358 // actually wanted, so copy it over if this is the first 359 // success and continue to try to get the qEcho response 360 packet = echo_response; 361 got_actual_response = true; 362 } 363 } else if (echo_packet_result == PacketResult::ErrorReplyTimeout) 364 continue; // Packet timed out, continue waiting for a response 365 else 366 break; // Something else went wrong getting the packet back, we 367 // failed and are done trying 368 } 369 } 370 371 // We weren't able to sync back up with the server, we must abort 372 // otherwise all responses might not be from the right packets... 373 if (sync_success) { 374 // We timed out, but were able to recover 375 if (got_actual_response) { 376 // We initially timed out, but we did get a response that came in 377 // before the successful reply to our qEcho packet, so lets say 378 // everything is fine... 379 return PacketResult::Success; 380 } 381 } else { 382 disconnected = true; 383 Disconnect(); 384 } 385 } 386 timed_out = true; 387 break; 388 case eConnectionStatusSuccess: 389 // printf ("status = success but error = %s\n", 390 // error.AsCString("<invalid>")); 391 break; 392 393 case eConnectionStatusEndOfFile: 394 case eConnectionStatusNoConnection: 395 case eConnectionStatusLostConnection: 396 case eConnectionStatusError: 397 disconnected = true; 398 Disconnect(); 399 break; 400 } 401 } 402 } 403 packet.Clear(); 404 if (disconnected) 405 return PacketResult::ErrorDisconnected; 406 if (timed_out) 407 return PacketResult::ErrorReplyTimeout; 408 else 409 return PacketResult::ErrorReplyFailed; 410 } 411 412 bool GDBRemoteCommunication::DecompressPacket() { 413 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS)); 414 415 if (!CompressionIsEnabled()) 416 return true; 417 418 size_t pkt_size = m_bytes.size(); 419 420 // Smallest possible compressed packet is $N#00 - an uncompressed empty 421 // reply, most commonly indicating an unsupported packet. Anything less than 422 // 5 characters, it's definitely not a compressed packet. 423 if (pkt_size < 5) 424 return true; 425 426 if (m_bytes[0] != '$' && m_bytes[0] != '%') 427 return true; 428 if (m_bytes[1] != 'C' && m_bytes[1] != 'N') 429 return true; 430 431 size_t hash_mark_idx = m_bytes.find('#'); 432 if (hash_mark_idx == std::string::npos) 433 return true; 434 if (hash_mark_idx + 2 >= m_bytes.size()) 435 return true; 436 437 if (!::isxdigit(m_bytes[hash_mark_idx + 1]) || 438 !::isxdigit(m_bytes[hash_mark_idx + 2])) 439 return true; 440 441 size_t content_length = 442 pkt_size - 443 5; // not counting '$', 'C' | 'N', '#', & the two hex checksum chars 444 size_t content_start = 2; // The first character of the 445 // compressed/not-compressed text of the packet 446 size_t checksum_idx = 447 hash_mark_idx + 448 1; // The first character of the two hex checksum characters 449 450 // Normally size_of_first_packet == m_bytes.size() but m_bytes may contain 451 // multiple packets. size_of_first_packet is the size of the initial packet 452 // which we'll replace with the decompressed version of, leaving the rest of 453 // m_bytes unmodified. 454 size_t size_of_first_packet = hash_mark_idx + 3; 455 456 // Compressed packets ("$C") start with a base10 number which is the size of 457 // the uncompressed payload, then a : and then the compressed data. e.g. 458 // $C1024:<binary>#00 Update content_start and content_length to only include 459 // the <binary> part of the packet. 460 461 uint64_t decompressed_bufsize = ULONG_MAX; 462 if (m_bytes[1] == 'C') { 463 size_t i = content_start; 464 while (i < hash_mark_idx && isdigit(m_bytes[i])) 465 i++; 466 if (i < hash_mark_idx && m_bytes[i] == ':') { 467 i++; 468 content_start = i; 469 content_length = hash_mark_idx - content_start; 470 std::string bufsize_str(m_bytes.data() + 2, i - 2 - 1); 471 errno = 0; 472 decompressed_bufsize = ::strtoul(bufsize_str.c_str(), nullptr, 10); 473 if (errno != 0 || decompressed_bufsize == ULONG_MAX) { 474 m_bytes.erase(0, size_of_first_packet); 475 return false; 476 } 477 } 478 } 479 480 if (GetSendAcks()) { 481 char packet_checksum_cstr[3]; 482 packet_checksum_cstr[0] = m_bytes[checksum_idx]; 483 packet_checksum_cstr[1] = m_bytes[checksum_idx + 1]; 484 packet_checksum_cstr[2] = '\0'; 485 long packet_checksum = strtol(packet_checksum_cstr, nullptr, 16); 486 487 long actual_checksum = CalculcateChecksum( 488 llvm::StringRef(m_bytes).substr(1, hash_mark_idx - 1)); 489 bool success = packet_checksum == actual_checksum; 490 if (!success) { 491 LLDB_LOGF(log, 492 "error: checksum mismatch: %.*s expected 0x%2.2x, got 0x%2.2x", 493 (int)(pkt_size), m_bytes.c_str(), (uint8_t)packet_checksum, 494 (uint8_t)actual_checksum); 495 } 496 // Send the ack or nack if needed 497 if (!success) { 498 SendNack(); 499 m_bytes.erase(0, size_of_first_packet); 500 return false; 501 } else { 502 SendAck(); 503 } 504 } 505 506 if (m_bytes[1] == 'N') { 507 // This packet was not compressed -- delete the 'N' character at the start 508 // and the packet may be processed as-is. 509 m_bytes.erase(1, 1); 510 return true; 511 } 512 513 // Reverse the gdb-remote binary escaping that was done to the compressed 514 // text to guard characters like '$', '#', '}', etc. 515 std::vector<uint8_t> unescaped_content; 516 unescaped_content.reserve(content_length); 517 size_t i = content_start; 518 while (i < hash_mark_idx) { 519 if (m_bytes[i] == '}') { 520 i++; 521 unescaped_content.push_back(m_bytes[i] ^ 0x20); 522 } else { 523 unescaped_content.push_back(m_bytes[i]); 524 } 525 i++; 526 } 527 528 uint8_t *decompressed_buffer = nullptr; 529 size_t decompressed_bytes = 0; 530 531 if (decompressed_bufsize != ULONG_MAX) { 532 decompressed_buffer = (uint8_t *)malloc(decompressed_bufsize); 533 if (decompressed_buffer == nullptr) { 534 m_bytes.erase(0, size_of_first_packet); 535 return false; 536 } 537 } 538 539 #if defined(HAVE_LIBCOMPRESSION) 540 if (m_compression_type == CompressionType::ZlibDeflate || 541 m_compression_type == CompressionType::LZFSE || 542 m_compression_type == CompressionType::LZ4 || 543 m_compression_type == CompressionType::LZMA) { 544 compression_algorithm compression_type; 545 if (m_compression_type == CompressionType::LZFSE) 546 compression_type = COMPRESSION_LZFSE; 547 else if (m_compression_type == CompressionType::ZlibDeflate) 548 compression_type = COMPRESSION_ZLIB; 549 else if (m_compression_type == CompressionType::LZ4) 550 compression_type = COMPRESSION_LZ4_RAW; 551 else if (m_compression_type == CompressionType::LZMA) 552 compression_type = COMPRESSION_LZMA; 553 554 if (m_decompression_scratch_type != m_compression_type) { 555 if (m_decompression_scratch) { 556 free (m_decompression_scratch); 557 m_decompression_scratch = nullptr; 558 } 559 size_t scratchbuf_size = 0; 560 if (m_compression_type == CompressionType::LZFSE) 561 scratchbuf_size = compression_decode_scratch_buffer_size (COMPRESSION_LZFSE); 562 else if (m_compression_type == CompressionType::LZ4) 563 scratchbuf_size = compression_decode_scratch_buffer_size (COMPRESSION_LZ4_RAW); 564 else if (m_compression_type == CompressionType::ZlibDeflate) 565 scratchbuf_size = compression_decode_scratch_buffer_size (COMPRESSION_ZLIB); 566 else if (m_compression_type == CompressionType::LZMA) 567 scratchbuf_size = compression_decode_scratch_buffer_size (COMPRESSION_LZMA); 568 else if (m_compression_type == CompressionType::LZFSE) 569 scratchbuf_size = compression_decode_scratch_buffer_size (COMPRESSION_LZFSE); 570 if (scratchbuf_size > 0) { 571 m_decompression_scratch = (void*) malloc (scratchbuf_size); 572 m_decompression_scratch_type = m_compression_type; 573 } 574 } 575 576 if (decompressed_bufsize != ULONG_MAX && decompressed_buffer != nullptr) { 577 decompressed_bytes = compression_decode_buffer( 578 decompressed_buffer, decompressed_bufsize, 579 (uint8_t *)unescaped_content.data(), unescaped_content.size(), 580 m_decompression_scratch, compression_type); 581 } 582 } 583 #endif 584 585 #if defined(HAVE_LIBZ) 586 if (decompressed_bytes == 0 && decompressed_bufsize != ULONG_MAX && 587 decompressed_buffer != nullptr && 588 m_compression_type == CompressionType::ZlibDeflate) { 589 z_stream stream; 590 memset(&stream, 0, sizeof(z_stream)); 591 stream.next_in = (Bytef *)unescaped_content.data(); 592 stream.avail_in = (uInt)unescaped_content.size(); 593 stream.total_in = 0; 594 stream.next_out = (Bytef *)decompressed_buffer; 595 stream.avail_out = decompressed_bufsize; 596 stream.total_out = 0; 597 stream.zalloc = Z_NULL; 598 stream.zfree = Z_NULL; 599 stream.opaque = Z_NULL; 600 601 if (inflateInit2(&stream, -15) == Z_OK) { 602 int status = inflate(&stream, Z_NO_FLUSH); 603 inflateEnd(&stream); 604 if (status == Z_STREAM_END) { 605 decompressed_bytes = stream.total_out; 606 } 607 } 608 } 609 #endif 610 611 if (decompressed_bytes == 0 || decompressed_buffer == nullptr) { 612 if (decompressed_buffer) 613 free(decompressed_buffer); 614 m_bytes.erase(0, size_of_first_packet); 615 return false; 616 } 617 618 std::string new_packet; 619 new_packet.reserve(decompressed_bytes + 6); 620 new_packet.push_back(m_bytes[0]); 621 new_packet.append((const char *)decompressed_buffer, decompressed_bytes); 622 new_packet.push_back('#'); 623 if (GetSendAcks()) { 624 uint8_t decompressed_checksum = CalculcateChecksum( 625 llvm::StringRef((const char *)decompressed_buffer, decompressed_bytes)); 626 char decompressed_checksum_str[3]; 627 snprintf(decompressed_checksum_str, 3, "%02x", decompressed_checksum); 628 new_packet.append(decompressed_checksum_str); 629 } else { 630 new_packet.push_back('0'); 631 new_packet.push_back('0'); 632 } 633 634 m_bytes.replace(0, size_of_first_packet, new_packet.data(), 635 new_packet.size()); 636 637 free(decompressed_buffer); 638 return true; 639 } 640 641 GDBRemoteCommunication::PacketType 642 GDBRemoteCommunication::CheckForPacket(const uint8_t *src, size_t src_len, 643 StringExtractorGDBRemote &packet) { 644 // Put the packet data into the buffer in a thread safe fashion 645 std::lock_guard<std::recursive_mutex> guard(m_bytes_mutex); 646 647 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PACKETS)); 648 649 if (src && src_len > 0) { 650 if (log && log->GetVerbose()) { 651 StreamString s; 652 LLDB_LOGF(log, "GDBRemoteCommunication::%s adding %u bytes: %.*s", 653 __FUNCTION__, (uint32_t)src_len, (uint32_t)src_len, src); 654 } 655 m_bytes.append((const char *)src, src_len); 656 } 657 658 bool isNotifyPacket = false; 659 660 // Parse up the packets into gdb remote packets 661 if (!m_bytes.empty()) { 662 // end_idx must be one past the last valid packet byte. Start it off with 663 // an invalid value that is the same as the current index. 664 size_t content_start = 0; 665 size_t content_length = 0; 666 size_t total_length = 0; 667 size_t checksum_idx = std::string::npos; 668 669 // Size of packet before it is decompressed, for logging purposes 670 size_t original_packet_size = m_bytes.size(); 671 if (CompressionIsEnabled()) { 672 if (!DecompressPacket()) { 673 packet.Clear(); 674 return GDBRemoteCommunication::PacketType::Standard; 675 } 676 } 677 678 switch (m_bytes[0]) { 679 case '+': // Look for ack 680 case '-': // Look for cancel 681 case '\x03': // ^C to halt target 682 content_length = total_length = 1; // The command is one byte long... 683 break; 684 685 case '%': // Async notify packet 686 isNotifyPacket = true; 687 LLVM_FALLTHROUGH; 688 689 case '$': 690 // Look for a standard gdb packet? 691 { 692 size_t hash_pos = m_bytes.find('#'); 693 if (hash_pos != std::string::npos) { 694 if (hash_pos + 2 < m_bytes.size()) { 695 checksum_idx = hash_pos + 1; 696 // Skip the dollar sign 697 content_start = 1; 698 // Don't include the # in the content or the $ in the content 699 // length 700 content_length = hash_pos - 1; 701 702 total_length = 703 hash_pos + 3; // Skip the # and the two hex checksum bytes 704 } else { 705 // Checksum bytes aren't all here yet 706 content_length = std::string::npos; 707 } 708 } 709 } 710 break; 711 712 default: { 713 // We have an unexpected byte and we need to flush all bad data that is 714 // in m_bytes, so we need to find the first byte that is a '+' (ACK), '-' 715 // (NACK), \x03 (CTRL+C interrupt), or '$' character (start of packet 716 // header) or of course, the end of the data in m_bytes... 717 const size_t bytes_len = m_bytes.size(); 718 bool done = false; 719 uint32_t idx; 720 for (idx = 1; !done && idx < bytes_len; ++idx) { 721 switch (m_bytes[idx]) { 722 case '+': 723 case '-': 724 case '\x03': 725 case '%': 726 case '$': 727 done = true; 728 break; 729 730 default: 731 break; 732 } 733 } 734 LLDB_LOGF(log, "GDBRemoteCommunication::%s tossing %u junk bytes: '%.*s'", 735 __FUNCTION__, idx - 1, idx - 1, m_bytes.c_str()); 736 m_bytes.erase(0, idx - 1); 737 } break; 738 } 739 740 if (content_length == std::string::npos) { 741 packet.Clear(); 742 return GDBRemoteCommunication::PacketType::Invalid; 743 } else if (total_length > 0) { 744 745 // We have a valid packet... 746 assert(content_length <= m_bytes.size()); 747 assert(total_length <= m_bytes.size()); 748 assert(content_length <= total_length); 749 size_t content_end = content_start + content_length; 750 751 bool success = true; 752 if (log) { 753 // If logging was just enabled and we have history, then dump out what 754 // we have to the log so we get the historical context. The Dump() call 755 // that logs all of the packet will set a boolean so that we don't dump 756 // this more than once 757 if (!m_history.DidDumpToLog()) 758 m_history.Dump(log); 759 760 bool binary = false; 761 // Only detect binary for packets that start with a '$' and have a 762 // '#CC' checksum 763 if (m_bytes[0] == '$' && total_length > 4) { 764 for (size_t i = 0; !binary && i < total_length; ++i) { 765 unsigned char c = m_bytes[i]; 766 if (!llvm::isPrint(c) && !llvm::isSpace(c)) { 767 binary = true; 768 } 769 } 770 } 771 if (binary) { 772 StreamString strm; 773 // Packet header... 774 if (CompressionIsEnabled()) 775 strm.Printf("<%4" PRIu64 ":%" PRIu64 "> read packet: %c", 776 (uint64_t)original_packet_size, (uint64_t)total_length, 777 m_bytes[0]); 778 else 779 strm.Printf("<%4" PRIu64 "> read packet: %c", 780 (uint64_t)total_length, m_bytes[0]); 781 for (size_t i = content_start; i < content_end; ++i) { 782 // Remove binary escaped bytes when displaying the packet... 783 const char ch = m_bytes[i]; 784 if (ch == 0x7d) { 785 // 0x7d is the escape character. The next character is to be 786 // XOR'd with 0x20. 787 const char escapee = m_bytes[++i] ^ 0x20; 788 strm.Printf("%2.2x", escapee); 789 } else { 790 strm.Printf("%2.2x", (uint8_t)ch); 791 } 792 } 793 // Packet footer... 794 strm.Printf("%c%c%c", m_bytes[total_length - 3], 795 m_bytes[total_length - 2], m_bytes[total_length - 1]); 796 log->PutString(strm.GetString()); 797 } else { 798 if (CompressionIsEnabled()) 799 LLDB_LOGF(log, "<%4" PRIu64 ":%" PRIu64 "> read packet: %.*s", 800 (uint64_t)original_packet_size, (uint64_t)total_length, 801 (int)(total_length), m_bytes.c_str()); 802 else 803 LLDB_LOGF(log, "<%4" PRIu64 "> read packet: %.*s", 804 (uint64_t)total_length, (int)(total_length), 805 m_bytes.c_str()); 806 } 807 } 808 809 m_history.AddPacket(m_bytes, total_length, 810 GDBRemotePacket::ePacketTypeRecv, total_length); 811 812 // Copy the packet from m_bytes to packet_str expanding the run-length 813 // encoding in the process. 814 std ::string packet_str = 815 ExpandRLE(m_bytes.substr(content_start, content_end - content_start)); 816 packet = StringExtractorGDBRemote(packet_str); 817 818 if (m_bytes[0] == '$' || m_bytes[0] == '%') { 819 assert(checksum_idx < m_bytes.size()); 820 if (::isxdigit(m_bytes[checksum_idx + 0]) || 821 ::isxdigit(m_bytes[checksum_idx + 1])) { 822 if (GetSendAcks()) { 823 const char *packet_checksum_cstr = &m_bytes[checksum_idx]; 824 char packet_checksum = strtol(packet_checksum_cstr, nullptr, 16); 825 char actual_checksum = CalculcateChecksum( 826 llvm::StringRef(m_bytes).slice(content_start, content_end)); 827 success = packet_checksum == actual_checksum; 828 if (!success) { 829 LLDB_LOGF(log, 830 "error: checksum mismatch: %.*s expected 0x%2.2x, " 831 "got 0x%2.2x", 832 (int)(total_length), m_bytes.c_str(), 833 (uint8_t)packet_checksum, (uint8_t)actual_checksum); 834 } 835 // Send the ack or nack if needed 836 if (!success) 837 SendNack(); 838 else 839 SendAck(); 840 } 841 } else { 842 success = false; 843 LLDB_LOGF(log, "error: invalid checksum in packet: '%s'\n", 844 m_bytes.c_str()); 845 } 846 } 847 848 m_bytes.erase(0, total_length); 849 packet.SetFilePos(0); 850 851 if (isNotifyPacket) 852 return GDBRemoteCommunication::PacketType::Notify; 853 else 854 return GDBRemoteCommunication::PacketType::Standard; 855 } 856 } 857 packet.Clear(); 858 return GDBRemoteCommunication::PacketType::Invalid; 859 } 860 861 Status GDBRemoteCommunication::StartListenThread(const char *hostname, 862 uint16_t port) { 863 if (m_listen_thread.IsJoinable()) 864 return Status("listen thread already running"); 865 866 char listen_url[512]; 867 if (hostname && hostname[0]) 868 snprintf(listen_url, sizeof(listen_url), "listen://%s:%i", hostname, port); 869 else 870 snprintf(listen_url, sizeof(listen_url), "listen://%i", port); 871 m_listen_url = listen_url; 872 SetConnection(std::make_unique<ConnectionFileDescriptor>()); 873 llvm::Expected<HostThread> listen_thread = ThreadLauncher::LaunchThread( 874 listen_url, GDBRemoteCommunication::ListenThread, this); 875 if (!listen_thread) 876 return Status(listen_thread.takeError()); 877 m_listen_thread = *listen_thread; 878 879 return Status(); 880 } 881 882 bool GDBRemoteCommunication::JoinListenThread() { 883 if (m_listen_thread.IsJoinable()) 884 m_listen_thread.Join(nullptr); 885 return true; 886 } 887 888 lldb::thread_result_t 889 GDBRemoteCommunication::ListenThread(lldb::thread_arg_t arg) { 890 GDBRemoteCommunication *comm = (GDBRemoteCommunication *)arg; 891 Status error; 892 ConnectionFileDescriptor *connection = 893 (ConnectionFileDescriptor *)comm->GetConnection(); 894 895 if (connection) { 896 // Do the listen on another thread so we can continue on... 897 if (connection->Connect(comm->m_listen_url.c_str(), &error) != 898 eConnectionStatusSuccess) 899 comm->SetConnection(nullptr); 900 } 901 return {}; 902 } 903 904 Status GDBRemoteCommunication::StartDebugserverProcess( 905 const char *url, Platform *platform, ProcessLaunchInfo &launch_info, 906 uint16_t *port, const Args *inferior_args, int pass_comm_fd) { 907 Log *log(ProcessGDBRemoteLog::GetLogIfAllCategoriesSet(GDBR_LOG_PROCESS)); 908 LLDB_LOGF(log, "GDBRemoteCommunication::%s(url=%s, port=%" PRIu16 ")", 909 __FUNCTION__, url ? url : "<empty>", port ? *port : uint16_t(0)); 910 911 Status error; 912 // If we locate debugserver, keep that located version around 913 static FileSpec g_debugserver_file_spec; 914 915 char debugserver_path[PATH_MAX]; 916 FileSpec &debugserver_file_spec = launch_info.GetExecutableFile(); 917 918 Environment host_env = Host::GetEnvironment(); 919 920 // Always check to see if we have an environment override for the path to the 921 // debugserver to use and use it if we do. 922 std::string env_debugserver_path = host_env.lookup("LLDB_DEBUGSERVER_PATH"); 923 if (!env_debugserver_path.empty()) { 924 debugserver_file_spec.SetFile(env_debugserver_path, 925 FileSpec::Style::native); 926 LLDB_LOGF(log, 927 "GDBRemoteCommunication::%s() gdb-remote stub exe path set " 928 "from environment variable: %s", 929 __FUNCTION__, env_debugserver_path.c_str()); 930 } else 931 debugserver_file_spec = g_debugserver_file_spec; 932 bool debugserver_exists = 933 FileSystem::Instance().Exists(debugserver_file_spec); 934 if (!debugserver_exists) { 935 // The debugserver binary is in the LLDB.framework/Resources directory. 936 debugserver_file_spec = HostInfo::GetSupportExeDir(); 937 if (debugserver_file_spec) { 938 debugserver_file_spec.AppendPathComponent(DEBUGSERVER_BASENAME); 939 debugserver_exists = FileSystem::Instance().Exists(debugserver_file_spec); 940 if (debugserver_exists) { 941 LLDB_LOGF(log, 942 "GDBRemoteCommunication::%s() found gdb-remote stub exe '%s'", 943 __FUNCTION__, debugserver_file_spec.GetPath().c_str()); 944 945 g_debugserver_file_spec = debugserver_file_spec; 946 } else { 947 if (platform) 948 debugserver_file_spec = 949 platform->LocateExecutable(DEBUGSERVER_BASENAME); 950 else 951 debugserver_file_spec.Clear(); 952 if (debugserver_file_spec) { 953 // Platform::LocateExecutable() wouldn't return a path if it doesn't 954 // exist 955 debugserver_exists = true; 956 } else { 957 LLDB_LOGF(log, 958 "GDBRemoteCommunication::%s() could not find " 959 "gdb-remote stub exe '%s'", 960 __FUNCTION__, debugserver_file_spec.GetPath().c_str()); 961 } 962 // Don't cache the platform specific GDB server binary as it could 963 // change from platform to platform 964 g_debugserver_file_spec.Clear(); 965 } 966 } 967 } 968 969 if (debugserver_exists) { 970 debugserver_file_spec.GetPath(debugserver_path, sizeof(debugserver_path)); 971 972 Args &debugserver_args = launch_info.GetArguments(); 973 debugserver_args.Clear(); 974 975 // Start args with "debugserver /file/path -r --" 976 debugserver_args.AppendArgument(llvm::StringRef(debugserver_path)); 977 978 #if !defined(__APPLE__) 979 // First argument to lldb-server must be mode in which to run. 980 debugserver_args.AppendArgument(llvm::StringRef("gdbserver")); 981 #endif 982 983 // If a url is supplied then use it 984 if (url) 985 debugserver_args.AppendArgument(llvm::StringRef(url)); 986 987 if (pass_comm_fd >= 0) { 988 StreamString fd_arg; 989 fd_arg.Printf("--fd=%i", pass_comm_fd); 990 debugserver_args.AppendArgument(fd_arg.GetString()); 991 // Send "pass_comm_fd" down to the inferior so it can use it to 992 // communicate back with this process 993 launch_info.AppendDuplicateFileAction(pass_comm_fd, pass_comm_fd); 994 } 995 996 // use native registers, not the GDB registers 997 debugserver_args.AppendArgument(llvm::StringRef("--native-regs")); 998 999 if (launch_info.GetLaunchInSeparateProcessGroup()) { 1000 debugserver_args.AppendArgument(llvm::StringRef("--setsid")); 1001 } 1002 1003 llvm::SmallString<128> named_pipe_path; 1004 // socket_pipe is used by debug server to communicate back either 1005 // TCP port or domain socket name which it listens on. 1006 // The second purpose of the pipe to serve as a synchronization point - 1007 // once data is written to the pipe, debug server is up and running. 1008 Pipe socket_pipe; 1009 1010 // port is null when debug server should listen on domain socket - we're 1011 // not interested in port value but rather waiting for debug server to 1012 // become available. 1013 if (pass_comm_fd == -1) { 1014 if (url) { 1015 // Create a temporary file to get the stdout/stderr and redirect the output of 1016 // the command into this file. We will later read this file if all goes well 1017 // and fill the data into "command_output_ptr" 1018 #if defined(__APPLE__) 1019 // Binding to port zero, we need to figure out what port it ends up 1020 // using using a named pipe... 1021 error = socket_pipe.CreateWithUniqueName("debugserver-named-pipe", 1022 false, named_pipe_path); 1023 if (error.Fail()) { 1024 LLDB_LOGF(log, 1025 "GDBRemoteCommunication::%s() " 1026 "named pipe creation failed: %s", 1027 __FUNCTION__, error.AsCString()); 1028 return error; 1029 } 1030 debugserver_args.AppendArgument(llvm::StringRef("--named-pipe")); 1031 debugserver_args.AppendArgument(named_pipe_path); 1032 #else 1033 // Binding to port zero, we need to figure out what port it ends up 1034 // using using an unnamed pipe... 1035 error = socket_pipe.CreateNew(true); 1036 if (error.Fail()) { 1037 LLDB_LOGF(log, 1038 "GDBRemoteCommunication::%s() " 1039 "unnamed pipe creation failed: %s", 1040 __FUNCTION__, error.AsCString()); 1041 return error; 1042 } 1043 pipe_t write = socket_pipe.GetWritePipe(); 1044 debugserver_args.AppendArgument(llvm::StringRef("--pipe")); 1045 debugserver_args.AppendArgument(llvm::to_string(write)); 1046 launch_info.AppendCloseFileAction(socket_pipe.GetReadFileDescriptor()); 1047 #endif 1048 } else { 1049 // No host and port given, so lets listen on our end and make the 1050 // debugserver connect to us.. 1051 error = StartListenThread("127.0.0.1", 0); 1052 if (error.Fail()) { 1053 LLDB_LOGF(log, 1054 "GDBRemoteCommunication::%s() unable to start listen " 1055 "thread: %s", 1056 __FUNCTION__, error.AsCString()); 1057 return error; 1058 } 1059 1060 ConnectionFileDescriptor *connection = 1061 (ConnectionFileDescriptor *)GetConnection(); 1062 // Wait for 10 seconds to resolve the bound port 1063 uint16_t port_ = connection->GetListeningPort(std::chrono::seconds(10)); 1064 if (port_ > 0) { 1065 char port_cstr[32]; 1066 snprintf(port_cstr, sizeof(port_cstr), "127.0.0.1:%i", port_); 1067 // Send the host and port down that debugserver and specify an option 1068 // so that it connects back to the port we are listening to in this 1069 // process 1070 debugserver_args.AppendArgument(llvm::StringRef("--reverse-connect")); 1071 debugserver_args.AppendArgument(llvm::StringRef(port_cstr)); 1072 if (port) 1073 *port = port_; 1074 } else { 1075 error.SetErrorString("failed to bind to port 0 on 127.0.0.1"); 1076 LLDB_LOGF(log, "GDBRemoteCommunication::%s() failed: %s", 1077 __FUNCTION__, error.AsCString()); 1078 return error; 1079 } 1080 } 1081 } 1082 std::string env_debugserver_log_file = 1083 host_env.lookup("LLDB_DEBUGSERVER_LOG_FILE"); 1084 if (!env_debugserver_log_file.empty()) { 1085 debugserver_args.AppendArgument( 1086 llvm::formatv("--log-file={0}", env_debugserver_log_file).str()); 1087 } 1088 1089 #if defined(__APPLE__) 1090 const char *env_debugserver_log_flags = 1091 getenv("LLDB_DEBUGSERVER_LOG_FLAGS"); 1092 if (env_debugserver_log_flags) { 1093 debugserver_args.AppendArgument( 1094 llvm::formatv("--log-flags={0}", env_debugserver_log_flags).str()); 1095 } 1096 #else 1097 std::string env_debugserver_log_channels = 1098 host_env.lookup("LLDB_SERVER_LOG_CHANNELS"); 1099 if (!env_debugserver_log_channels.empty()) { 1100 debugserver_args.AppendArgument( 1101 llvm::formatv("--log-channels={0}", env_debugserver_log_channels) 1102 .str()); 1103 } 1104 #endif 1105 1106 // Add additional args, starting with LLDB_DEBUGSERVER_EXTRA_ARG_1 until an 1107 // env var doesn't come back. 1108 uint32_t env_var_index = 1; 1109 bool has_env_var; 1110 do { 1111 char env_var_name[64]; 1112 snprintf(env_var_name, sizeof(env_var_name), 1113 "LLDB_DEBUGSERVER_EXTRA_ARG_%" PRIu32, env_var_index++); 1114 std::string extra_arg = host_env.lookup(env_var_name); 1115 has_env_var = !extra_arg.empty(); 1116 1117 if (has_env_var) { 1118 debugserver_args.AppendArgument(llvm::StringRef(extra_arg)); 1119 LLDB_LOGF(log, 1120 "GDBRemoteCommunication::%s adding env var %s contents " 1121 "to stub command line (%s)", 1122 __FUNCTION__, env_var_name, extra_arg.c_str()); 1123 } 1124 } while (has_env_var); 1125 1126 if (inferior_args && inferior_args->GetArgumentCount() > 0) { 1127 debugserver_args.AppendArgument(llvm::StringRef("--")); 1128 debugserver_args.AppendArguments(*inferior_args); 1129 } 1130 1131 // Copy the current environment to the gdbserver/debugserver instance 1132 launch_info.GetEnvironment() = host_env; 1133 1134 // Close STDIN, STDOUT and STDERR. 1135 launch_info.AppendCloseFileAction(STDIN_FILENO); 1136 launch_info.AppendCloseFileAction(STDOUT_FILENO); 1137 launch_info.AppendCloseFileAction(STDERR_FILENO); 1138 1139 // Redirect STDIN, STDOUT and STDERR to "/dev/null". 1140 launch_info.AppendSuppressFileAction(STDIN_FILENO, true, false); 1141 launch_info.AppendSuppressFileAction(STDOUT_FILENO, false, true); 1142 launch_info.AppendSuppressFileAction(STDERR_FILENO, false, true); 1143 1144 if (log) { 1145 StreamString string_stream; 1146 Platform *const platform = nullptr; 1147 launch_info.Dump(string_stream, platform); 1148 LLDB_LOGF(log, "launch info for gdb-remote stub:\n%s", 1149 string_stream.GetData()); 1150 } 1151 error = Host::LaunchProcess(launch_info); 1152 1153 if (error.Success() && 1154 (launch_info.GetProcessID() != LLDB_INVALID_PROCESS_ID) && 1155 pass_comm_fd == -1) { 1156 if (named_pipe_path.size() > 0) { 1157 error = socket_pipe.OpenAsReader(named_pipe_path, false); 1158 if (error.Fail()) 1159 LLDB_LOGF(log, 1160 "GDBRemoteCommunication::%s() " 1161 "failed to open named pipe %s for reading: %s", 1162 __FUNCTION__, named_pipe_path.c_str(), error.AsCString()); 1163 } 1164 1165 if (socket_pipe.CanWrite()) 1166 socket_pipe.CloseWriteFileDescriptor(); 1167 if (socket_pipe.CanRead()) { 1168 char port_cstr[PATH_MAX] = {0}; 1169 port_cstr[0] = '\0'; 1170 size_t num_bytes = sizeof(port_cstr); 1171 // Read port from pipe with 10 second timeout. 1172 error = socket_pipe.ReadWithTimeout( 1173 port_cstr, num_bytes, std::chrono::seconds{10}, num_bytes); 1174 if (error.Success() && (port != nullptr)) { 1175 assert(num_bytes > 0 && port_cstr[num_bytes - 1] == '\0'); 1176 uint16_t child_port = StringConvert::ToUInt32(port_cstr, 0); 1177 if (*port == 0 || *port == child_port) { 1178 *port = child_port; 1179 LLDB_LOGF(log, 1180 "GDBRemoteCommunication::%s() " 1181 "debugserver listens %u port", 1182 __FUNCTION__, *port); 1183 } else { 1184 LLDB_LOGF(log, 1185 "GDBRemoteCommunication::%s() " 1186 "debugserver listening on port " 1187 "%d but requested port was %d", 1188 __FUNCTION__, (uint32_t)child_port, (uint32_t)(*port)); 1189 } 1190 } else { 1191 LLDB_LOGF(log, 1192 "GDBRemoteCommunication::%s() " 1193 "failed to read a port value from pipe %s: %s", 1194 __FUNCTION__, named_pipe_path.c_str(), error.AsCString()); 1195 } 1196 socket_pipe.Close(); 1197 } 1198 1199 if (named_pipe_path.size() > 0) { 1200 const auto err = socket_pipe.Delete(named_pipe_path); 1201 if (err.Fail()) { 1202 LLDB_LOGF(log, 1203 "GDBRemoteCommunication::%s failed to delete pipe %s: %s", 1204 __FUNCTION__, named_pipe_path.c_str(), err.AsCString()); 1205 } 1206 } 1207 1208 // Make sure we actually connect with the debugserver... 1209 JoinListenThread(); 1210 } 1211 } else { 1212 error.SetErrorStringWithFormat("unable to locate " DEBUGSERVER_BASENAME); 1213 } 1214 1215 if (error.Fail()) { 1216 LLDB_LOGF(log, "GDBRemoteCommunication::%s() failed: %s", __FUNCTION__, 1217 error.AsCString()); 1218 } 1219 1220 return error; 1221 } 1222 1223 void GDBRemoteCommunication::DumpHistory(Stream &strm) { m_history.Dump(strm); } 1224 1225 void GDBRemoteCommunication::SetPacketRecorder( 1226 repro::PacketRecorder *recorder) { 1227 m_history.SetRecorder(recorder); 1228 } 1229 1230 llvm::Error 1231 GDBRemoteCommunication::ConnectLocally(GDBRemoteCommunication &client, 1232 GDBRemoteCommunication &server) { 1233 const bool child_processes_inherit = false; 1234 const int backlog = 5; 1235 TCPSocket listen_socket(true, child_processes_inherit); 1236 if (llvm::Error error = 1237 listen_socket.Listen("127.0.0.1:0", backlog).ToError()) 1238 return error; 1239 1240 Socket *accept_socket; 1241 std::future<Status> accept_status = std::async( 1242 std::launch::async, [&] { return listen_socket.Accept(accept_socket); }); 1243 1244 llvm::SmallString<32> remote_addr; 1245 llvm::raw_svector_ostream(remote_addr) 1246 << "connect://127.0.0.1:" << listen_socket.GetLocalPortNumber(); 1247 1248 std::unique_ptr<ConnectionFileDescriptor> conn_up( 1249 new ConnectionFileDescriptor()); 1250 Status status; 1251 if (conn_up->Connect(remote_addr, &status) != lldb::eConnectionStatusSuccess) 1252 return llvm::createStringError(llvm::inconvertibleErrorCode(), 1253 "Unable to connect: %s", status.AsCString()); 1254 1255 client.SetConnection(std::move(conn_up)); 1256 if (llvm::Error error = accept_status.get().ToError()) 1257 return error; 1258 1259 server.SetConnection( 1260 std::make_unique<ConnectionFileDescriptor>(accept_socket)); 1261 return llvm::Error::success(); 1262 } 1263 1264 GDBRemoteCommunication::ScopedTimeout::ScopedTimeout( 1265 GDBRemoteCommunication &gdb_comm, std::chrono::seconds timeout) 1266 : m_gdb_comm(gdb_comm), m_timeout_modified(false) { 1267 auto curr_timeout = gdb_comm.GetPacketTimeout(); 1268 // Only update the timeout if the timeout is greater than the current 1269 // timeout. If the current timeout is larger, then just use that. 1270 if (curr_timeout < timeout) { 1271 m_timeout_modified = true; 1272 m_saved_timeout = m_gdb_comm.SetPacketTimeout(timeout); 1273 } 1274 } 1275 1276 GDBRemoteCommunication::ScopedTimeout::~ScopedTimeout() { 1277 // Only restore the timeout if we set it in the constructor. 1278 if (m_timeout_modified) 1279 m_gdb_comm.SetPacketTimeout(m_saved_timeout); 1280 } 1281 1282 // This function is called via the Communications class read thread when bytes 1283 // become available for this connection. This function will consume all 1284 // incoming bytes and try to parse whole packets as they become available. Full 1285 // packets are placed in a queue, so that all packet requests can simply pop 1286 // from this queue. Async notification packets will be dispatched immediately 1287 // to the ProcessGDBRemote Async thread via an event. 1288 void GDBRemoteCommunication::AppendBytesToCache(const uint8_t *bytes, 1289 size_t len, bool broadcast, 1290 lldb::ConnectionStatus status) { 1291 StringExtractorGDBRemote packet; 1292 1293 while (true) { 1294 PacketType type = CheckForPacket(bytes, len, packet); 1295 1296 // scrub the data so we do not pass it back to CheckForPacket on future 1297 // passes of the loop 1298 bytes = nullptr; 1299 len = 0; 1300 1301 // we may have received no packet so lets bail out 1302 if (type == PacketType::Invalid) 1303 break; 1304 1305 if (type == PacketType::Standard) { 1306 // scope for the mutex 1307 { 1308 // lock down the packet queue 1309 std::lock_guard<std::mutex> guard(m_packet_queue_mutex); 1310 // push a new packet into the queue 1311 m_packet_queue.push(packet); 1312 // Signal condition variable that we have a packet 1313 m_condition_queue_not_empty.notify_one(); 1314 } 1315 } 1316 1317 if (type == PacketType::Notify) { 1318 // put this packet into an event 1319 const char *pdata = packet.GetStringRef().data(); 1320 1321 // as the communication class, we are a broadcaster and the async thread 1322 // is tuned to listen to us 1323 BroadcastEvent(eBroadcastBitGdbReadThreadGotNotify, 1324 new EventDataBytes(pdata)); 1325 } 1326 } 1327 } 1328 1329 void llvm::format_provider<GDBRemoteCommunication::PacketResult>::format( 1330 const GDBRemoteCommunication::PacketResult &result, raw_ostream &Stream, 1331 StringRef Style) { 1332 using PacketResult = GDBRemoteCommunication::PacketResult; 1333 1334 switch (result) { 1335 case PacketResult::Success: 1336 Stream << "Success"; 1337 break; 1338 case PacketResult::ErrorSendFailed: 1339 Stream << "ErrorSendFailed"; 1340 break; 1341 case PacketResult::ErrorSendAck: 1342 Stream << "ErrorSendAck"; 1343 break; 1344 case PacketResult::ErrorReplyFailed: 1345 Stream << "ErrorReplyFailed"; 1346 break; 1347 case PacketResult::ErrorReplyTimeout: 1348 Stream << "ErrorReplyTimeout"; 1349 break; 1350 case PacketResult::ErrorReplyInvalid: 1351 Stream << "ErrorReplyInvalid"; 1352 break; 1353 case PacketResult::ErrorReplyAck: 1354 Stream << "ErrorReplyAck"; 1355 break; 1356 case PacketResult::ErrorDisconnected: 1357 Stream << "ErrorDisconnected"; 1358 break; 1359 case PacketResult::ErrorNoSequenceLock: 1360 Stream << "ErrorNoSequenceLock"; 1361 break; 1362 } 1363 } 1364 1365 std::string GDBRemoteCommunication::ExpandRLE(std::string packet) { 1366 // Reserve enough byte for the most common case (no RLE used). 1367 std::string decoded; 1368 decoded.reserve(packet.size()); 1369 for (std::string::const_iterator c = packet.begin(); c != packet.end(); ++c) { 1370 if (*c == '*') { 1371 // '*' indicates RLE. Next character will give us the repeat count and 1372 // previous character is what is to be repeated. 1373 char char_to_repeat = decoded.back(); 1374 // Number of time the previous character is repeated. 1375 int repeat_count = *++c + 3 - ' '; 1376 // We have the char_to_repeat and repeat_count. Now push it in the 1377 // packet. 1378 for (int i = 0; i < repeat_count; ++i) 1379 decoded.push_back(char_to_repeat); 1380 } else if (*c == 0x7d) { 1381 // 0x7d is the escape character. The next character is to be XOR'd with 1382 // 0x20. 1383 char escapee = *++c ^ 0x20; 1384 decoded.push_back(escapee); 1385 } else { 1386 decoded.push_back(*c); 1387 } 1388 } 1389 return decoded; 1390 } 1391