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