1 //===-- GDBRemoteCommunication.cpp ------------------------------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10
11 #include "GDBRemoteCommunication.h"
12
13 // C Includes
14 #include <limits.h>
15 #include <string.h>
16
17 // C++ Includes
18 // Other libraries and framework includes
19 #include "lldb/Core/Log.h"
20 #include "lldb/Core/StreamFile.h"
21 #include "lldb/Core/StreamString.h"
22 #include "lldb/Host/FileSpec.h"
23 #include "lldb/Host/Host.h"
24 #include "lldb/Host/TimeValue.h"
25 #include "lldb/Target/Process.h"
26
27 // Project includes
28 #include "ProcessGDBRemoteLog.h"
29
30 #define DEBUGSERVER_BASENAME "debugserver"
31
32 using namespace lldb;
33 using namespace lldb_private;
34
History(uint32_t size)35 GDBRemoteCommunication::History::History (uint32_t size) :
36 m_packets(),
37 m_curr_idx (0),
38 m_total_packet_count (0),
39 m_dumped_to_log (false)
40 {
41 m_packets.resize(size);
42 }
43
~History()44 GDBRemoteCommunication::History::~History ()
45 {
46 }
47
48 void
AddPacket(char packet_char,PacketType type,uint32_t bytes_transmitted)49 GDBRemoteCommunication::History::AddPacket (char packet_char,
50 PacketType type,
51 uint32_t bytes_transmitted)
52 {
53 const size_t size = m_packets.size();
54 if (size > 0)
55 {
56 const uint32_t idx = GetNextIndex();
57 m_packets[idx].packet.assign (1, packet_char);
58 m_packets[idx].type = type;
59 m_packets[idx].bytes_transmitted = bytes_transmitted;
60 m_packets[idx].packet_idx = m_total_packet_count;
61 m_packets[idx].tid = Host::GetCurrentThreadID();
62 }
63 }
64
65 void
AddPacket(const std::string & src,uint32_t src_len,PacketType type,uint32_t bytes_transmitted)66 GDBRemoteCommunication::History::AddPacket (const std::string &src,
67 uint32_t src_len,
68 PacketType type,
69 uint32_t bytes_transmitted)
70 {
71 const size_t size = m_packets.size();
72 if (size > 0)
73 {
74 const uint32_t idx = GetNextIndex();
75 m_packets[idx].packet.assign (src, 0, src_len);
76 m_packets[idx].type = type;
77 m_packets[idx].bytes_transmitted = bytes_transmitted;
78 m_packets[idx].packet_idx = m_total_packet_count;
79 m_packets[idx].tid = Host::GetCurrentThreadID();
80 }
81 }
82
83 void
Dump(lldb_private::Stream & strm) const84 GDBRemoteCommunication::History::Dump (lldb_private::Stream &strm) const
85 {
86 const uint32_t size = GetNumPacketsInHistory ();
87 const uint32_t first_idx = GetFirstSavedPacketIndex ();
88 const uint32_t stop_idx = m_curr_idx + size;
89 for (uint32_t i = first_idx; i < stop_idx; ++i)
90 {
91 const uint32_t idx = NormalizeIndex (i);
92 const Entry &entry = m_packets[idx];
93 if (entry.type == ePacketTypeInvalid || entry.packet.empty())
94 break;
95 strm.Printf ("history[%u] tid=0x%4.4" PRIx64 " <%4u> %s packet: %s\n",
96 entry.packet_idx,
97 entry.tid,
98 entry.bytes_transmitted,
99 (entry.type == ePacketTypeSend) ? "send" : "read",
100 entry.packet.c_str());
101 }
102 }
103
104 void
Dump(lldb_private::Log * log) const105 GDBRemoteCommunication::History::Dump (lldb_private::Log *log) const
106 {
107 if (log && !m_dumped_to_log)
108 {
109 m_dumped_to_log = true;
110 const uint32_t size = GetNumPacketsInHistory ();
111 const uint32_t first_idx = GetFirstSavedPacketIndex ();
112 const uint32_t stop_idx = m_curr_idx + size;
113 for (uint32_t i = first_idx; i < stop_idx; ++i)
114 {
115 const uint32_t idx = NormalizeIndex (i);
116 const Entry &entry = m_packets[idx];
117 if (entry.type == ePacketTypeInvalid || entry.packet.empty())
118 break;
119 log->Printf ("history[%u] tid=0x%4.4" PRIx64 " <%4u> %s packet: %s",
120 entry.packet_idx,
121 entry.tid,
122 entry.bytes_transmitted,
123 (entry.type == ePacketTypeSend) ? "send" : "read",
124 entry.packet.c_str());
125 }
126 }
127 }
128
129 //----------------------------------------------------------------------
130 // GDBRemoteCommunication constructor
131 //----------------------------------------------------------------------
GDBRemoteCommunication(const char * comm_name,const char * listener_name,bool is_platform)132 GDBRemoteCommunication::GDBRemoteCommunication(const char *comm_name,
133 const char *listener_name,
134 bool is_platform) :
135 Communication(comm_name),
136 m_packet_timeout (1),
137 m_sequence_mutex (Mutex::eMutexTypeRecursive),
138 m_public_is_running (false),
139 m_private_is_running (false),
140 m_history (512),
141 m_send_acks (true),
142 m_is_platform (is_platform)
143 {
144 }
145
146 //----------------------------------------------------------------------
147 // Destructor
148 //----------------------------------------------------------------------
~GDBRemoteCommunication()149 GDBRemoteCommunication::~GDBRemoteCommunication()
150 {
151 if (IsConnected())
152 {
153 Disconnect();
154 }
155 }
156
157 char
CalculcateChecksum(const char * payload,size_t payload_length)158 GDBRemoteCommunication::CalculcateChecksum (const char *payload, size_t payload_length)
159 {
160 int checksum = 0;
161
162 // We only need to compute the checksum if we are sending acks
163 if (GetSendAcks ())
164 {
165 for (size_t i = 0; i < payload_length; ++i)
166 checksum += payload[i];
167 }
168 return checksum & 255;
169 }
170
171 size_t
SendAck()172 GDBRemoteCommunication::SendAck ()
173 {
174 Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS));
175 ConnectionStatus status = eConnectionStatusSuccess;
176 char ch = '+';
177 const size_t bytes_written = Write (&ch, 1, status, NULL);
178 if (log)
179 log->Printf ("<%4zu> send packet: %c", bytes_written, ch);
180 m_history.AddPacket (ch, History::ePacketTypeSend, bytes_written);
181 return bytes_written;
182 }
183
184 size_t
SendNack()185 GDBRemoteCommunication::SendNack ()
186 {
187 Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS));
188 ConnectionStatus status = eConnectionStatusSuccess;
189 char ch = '-';
190 const size_t bytes_written = Write (&ch, 1, status, NULL);
191 if (log)
192 log->Printf ("<%4zu> send packet: %c", bytes_written, ch);
193 m_history.AddPacket (ch, History::ePacketTypeSend, bytes_written);
194 return bytes_written;
195 }
196
197 size_t
SendPacket(const char * payload,size_t payload_length)198 GDBRemoteCommunication::SendPacket (const char *payload, size_t payload_length)
199 {
200 Mutex::Locker locker(m_sequence_mutex);
201 return SendPacketNoLock (payload, payload_length);
202 }
203
204 size_t
SendPacketNoLock(const char * payload,size_t payload_length)205 GDBRemoteCommunication::SendPacketNoLock (const char *payload, size_t payload_length)
206 {
207 if (IsConnected())
208 {
209 StreamString packet(0, 4, eByteOrderBig);
210
211 packet.PutChar('$');
212 packet.Write (payload, payload_length);
213 packet.PutChar('#');
214 packet.PutHex8(CalculcateChecksum (payload, payload_length));
215
216 Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS));
217 ConnectionStatus status = eConnectionStatusSuccess;
218 size_t bytes_written = Write (packet.GetData(), packet.GetSize(), status, NULL);
219 if (log)
220 {
221 // If logging was just enabled and we have history, then dump out what
222 // we have to the log so we get the historical context. The Dump() call that
223 // logs all of the packet will set a boolean so that we don't dump this more
224 // than once
225 if (!m_history.DidDumpToLog ())
226 m_history.Dump (log);
227
228 log->Printf ("<%4zu> send packet: %.*s", bytes_written, (int)packet.GetSize(), packet.GetData());
229 }
230
231 m_history.AddPacket (packet.GetString(), packet.GetSize(), History::ePacketTypeSend, bytes_written);
232
233
234 if (bytes_written == packet.GetSize())
235 {
236 if (GetSendAcks ())
237 {
238 if (GetAck () != '+')
239 {
240 if (log)
241 log->Printf("get ack failed...");
242 return 0;
243 }
244 }
245 }
246 else
247 {
248 if (log)
249 log->Printf ("error: failed to send packet: %.*s", (int)packet.GetSize(), packet.GetData());
250 }
251 return bytes_written;
252 }
253 return 0;
254 }
255
256 char
GetAck()257 GDBRemoteCommunication::GetAck ()
258 {
259 StringExtractorGDBRemote packet;
260 if (WaitForPacketWithTimeoutMicroSecondsNoLock (packet, GetPacketTimeoutInMicroSeconds ()) == 1)
261 return packet.GetChar();
262 return 0;
263 }
264
265 bool
GetSequenceMutex(Mutex::Locker & locker,const char * failure_message)266 GDBRemoteCommunication::GetSequenceMutex (Mutex::Locker& locker, const char *failure_message)
267 {
268 if (IsRunning())
269 return locker.TryLock (m_sequence_mutex, failure_message);
270
271 locker.Lock (m_sequence_mutex);
272 return true;
273 }
274
275
276 bool
WaitForNotRunningPrivate(const TimeValue * timeout_ptr)277 GDBRemoteCommunication::WaitForNotRunningPrivate (const TimeValue *timeout_ptr)
278 {
279 return m_private_is_running.WaitForValueEqualTo (false, timeout_ptr, NULL);
280 }
281
282 size_t
WaitForPacketWithTimeoutMicroSecondsNoLock(StringExtractorGDBRemote & packet,uint32_t timeout_usec)283 GDBRemoteCommunication::WaitForPacketWithTimeoutMicroSecondsNoLock (StringExtractorGDBRemote &packet, uint32_t timeout_usec)
284 {
285 uint8_t buffer[8192];
286 Error error;
287
288 Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS | GDBR_LOG_VERBOSE));
289
290 // Check for a packet from our cache first without trying any reading...
291 if (CheckForPacket (NULL, 0, packet))
292 return packet.GetStringRef().size();
293
294 bool timed_out = false;
295 while (IsConnected() && !timed_out)
296 {
297 lldb::ConnectionStatus status = eConnectionStatusNoConnection;
298 size_t bytes_read = Read (buffer, sizeof(buffer), timeout_usec, status, &error);
299
300 if (log)
301 log->Printf ("%s: Read (buffer, (sizeof(buffer), timeout_usec = 0x%x, status = %s, error = %s) => bytes_read = %" PRIu64,
302 __PRETTY_FUNCTION__,
303 timeout_usec,
304 Communication::ConnectionStatusAsCString (status),
305 error.AsCString(),
306 (uint64_t)bytes_read);
307
308 if (bytes_read > 0)
309 {
310 if (CheckForPacket (buffer, bytes_read, packet))
311 return packet.GetStringRef().size();
312 }
313 else
314 {
315 switch (status)
316 {
317 case eConnectionStatusTimedOut:
318 timed_out = true;
319 break;
320 case eConnectionStatusSuccess:
321 //printf ("status = success but error = %s\n", error.AsCString("<invalid>"));
322 break;
323
324 case eConnectionStatusEndOfFile:
325 case eConnectionStatusNoConnection:
326 case eConnectionStatusLostConnection:
327 case eConnectionStatusError:
328 Disconnect();
329 break;
330 }
331 }
332 }
333 packet.Clear ();
334 return 0;
335 }
336
337 bool
CheckForPacket(const uint8_t * src,size_t src_len,StringExtractorGDBRemote & packet)338 GDBRemoteCommunication::CheckForPacket (const uint8_t *src, size_t src_len, StringExtractorGDBRemote &packet)
339 {
340 // Put the packet data into the buffer in a thread safe fashion
341 Mutex::Locker locker(m_bytes_mutex);
342
343 Log *log (ProcessGDBRemoteLog::GetLogIfAllCategoriesSet (GDBR_LOG_PACKETS));
344
345 if (src && src_len > 0)
346 {
347 if (log && log->GetVerbose())
348 {
349 StreamString s;
350 log->Printf ("GDBRemoteCommunication::%s adding %u bytes: %.*s",
351 __FUNCTION__,
352 (uint32_t)src_len,
353 (uint32_t)src_len,
354 src);
355 }
356 m_bytes.append ((const char *)src, src_len);
357 }
358
359 // Parse up the packets into gdb remote packets
360 if (!m_bytes.empty())
361 {
362 // end_idx must be one past the last valid packet byte. Start
363 // it off with an invalid value that is the same as the current
364 // index.
365 size_t content_start = 0;
366 size_t content_length = 0;
367 size_t total_length = 0;
368 size_t checksum_idx = std::string::npos;
369
370 switch (m_bytes[0])
371 {
372 case '+': // Look for ack
373 case '-': // Look for cancel
374 case '\x03': // ^C to halt target
375 content_length = total_length = 1; // The command is one byte long...
376 break;
377
378 case '$':
379 // Look for a standard gdb packet?
380 {
381 size_t hash_pos = m_bytes.find('#');
382 if (hash_pos != std::string::npos)
383 {
384 if (hash_pos + 2 < m_bytes.size())
385 {
386 checksum_idx = hash_pos + 1;
387 // Skip the dollar sign
388 content_start = 1;
389 // Don't include the # in the content or the $ in the content length
390 content_length = hash_pos - 1;
391
392 total_length = hash_pos + 3; // Skip the # and the two hex checksum bytes
393 }
394 else
395 {
396 // Checksum bytes aren't all here yet
397 content_length = std::string::npos;
398 }
399 }
400 }
401 break;
402
403 default:
404 {
405 // We have an unexpected byte and we need to flush all bad
406 // data that is in m_bytes, so we need to find the first
407 // byte that is a '+' (ACK), '-' (NACK), \x03 (CTRL+C interrupt),
408 // or '$' character (start of packet header) or of course,
409 // the end of the data in m_bytes...
410 const size_t bytes_len = m_bytes.size();
411 bool done = false;
412 uint32_t idx;
413 for (idx = 1; !done && idx < bytes_len; ++idx)
414 {
415 switch (m_bytes[idx])
416 {
417 case '+':
418 case '-':
419 case '\x03':
420 case '$':
421 done = true;
422 break;
423
424 default:
425 break;
426 }
427 }
428 if (log)
429 log->Printf ("GDBRemoteCommunication::%s tossing %u junk bytes: '%.*s'",
430 __FUNCTION__, idx, idx, m_bytes.c_str());
431 m_bytes.erase(0, idx);
432 }
433 break;
434 }
435
436 if (content_length == std::string::npos)
437 {
438 packet.Clear();
439 return false;
440 }
441 else if (total_length > 0)
442 {
443
444 // We have a valid packet...
445 assert (content_length <= m_bytes.size());
446 assert (total_length <= m_bytes.size());
447 assert (content_length <= total_length);
448
449 bool success = true;
450 std::string &packet_str = packet.GetStringRef();
451
452
453 if (log)
454 {
455 // If logging was just enabled and we have history, then dump out what
456 // we have to the log so we get the historical context. The Dump() call that
457 // logs all of the packet will set a boolean so that we don't dump this more
458 // than once
459 if (!m_history.DidDumpToLog ())
460 m_history.Dump (log);
461
462 log->Printf ("<%4zu> read packet: %.*s", total_length, (int)(total_length), m_bytes.c_str());
463 }
464
465 m_history.AddPacket (m_bytes.c_str(), total_length, History::ePacketTypeRecv, total_length);
466
467 packet_str.assign (m_bytes, content_start, content_length);
468
469 if (m_bytes[0] == '$')
470 {
471 assert (checksum_idx < m_bytes.size());
472 if (::isxdigit (m_bytes[checksum_idx+0]) ||
473 ::isxdigit (m_bytes[checksum_idx+1]))
474 {
475 if (GetSendAcks ())
476 {
477 const char *packet_checksum_cstr = &m_bytes[checksum_idx];
478 char packet_checksum = strtol (packet_checksum_cstr, NULL, 16);
479 char actual_checksum = CalculcateChecksum (packet_str.c_str(), packet_str.size());
480 success = packet_checksum == actual_checksum;
481 if (!success)
482 {
483 if (log)
484 log->Printf ("error: checksum mismatch: %.*s expected 0x%2.2x, got 0x%2.2x",
485 (int)(total_length),
486 m_bytes.c_str(),
487 (uint8_t)packet_checksum,
488 (uint8_t)actual_checksum);
489 }
490 // Send the ack or nack if needed
491 if (!success)
492 SendNack();
493 else
494 SendAck();
495 }
496 }
497 else
498 {
499 success = false;
500 if (log)
501 log->Printf ("error: invalid checksum in packet: '%s'\n", m_bytes.c_str());
502 }
503 }
504
505 m_bytes.erase(0, total_length);
506 packet.SetFilePos(0);
507 return success;
508 }
509 }
510 packet.Clear();
511 return false;
512 }
513
514 Error
StartDebugserverProcess(const char * debugserver_url,const char * unix_socket_name,lldb_private::ProcessLaunchInfo & launch_info)515 GDBRemoteCommunication::StartDebugserverProcess (const char *debugserver_url,
516 const char *unix_socket_name, // For handshaking
517 lldb_private::ProcessLaunchInfo &launch_info)
518 {
519 Error error;
520 // If we locate debugserver, keep that located version around
521 static FileSpec g_debugserver_file_spec;
522
523 // This function will fill in the launch information for the debugserver
524 // instance that gets launched.
525 launch_info.Clear();
526
527 char debugserver_path[PATH_MAX];
528 FileSpec &debugserver_file_spec = launch_info.GetExecutableFile();
529
530 // Always check to see if we have an environment override for the path
531 // to the debugserver to use and use it if we do.
532 const char *env_debugserver_path = getenv("LLDB_DEBUGSERVER_PATH");
533 if (env_debugserver_path)
534 debugserver_file_spec.SetFile (env_debugserver_path, false);
535 else
536 debugserver_file_spec = g_debugserver_file_spec;
537 bool debugserver_exists = debugserver_file_spec.Exists();
538 if (!debugserver_exists)
539 {
540 // The debugserver binary is in the LLDB.framework/Resources
541 // directory.
542 if (Host::GetLLDBPath (ePathTypeSupportExecutableDir, debugserver_file_spec))
543 {
544 debugserver_file_spec.GetFilename().SetCString(DEBUGSERVER_BASENAME);
545 debugserver_exists = debugserver_file_spec.Exists();
546 if (debugserver_exists)
547 {
548 g_debugserver_file_spec = debugserver_file_spec;
549 }
550 else
551 {
552 g_debugserver_file_spec.Clear();
553 debugserver_file_spec.Clear();
554 }
555 }
556 }
557
558 if (debugserver_exists)
559 {
560 debugserver_file_spec.GetPath (debugserver_path, sizeof(debugserver_path));
561
562 Args &debugserver_args = launch_info.GetArguments();
563 debugserver_args.Clear();
564 char arg_cstr[PATH_MAX];
565
566 // Start args with "debugserver /file/path -r --"
567 debugserver_args.AppendArgument(debugserver_path);
568 debugserver_args.AppendArgument(debugserver_url);
569 // use native registers, not the GDB registers
570 debugserver_args.AppendArgument("--native-regs");
571 // make debugserver run in its own session so signals generated by
572 // special terminal key sequences (^C) don't affect debugserver
573 debugserver_args.AppendArgument("--setsid");
574
575 if (unix_socket_name && unix_socket_name[0])
576 {
577 debugserver_args.AppendArgument("--unix-socket");
578 debugserver_args.AppendArgument(unix_socket_name);
579 }
580
581 const char *env_debugserver_log_file = getenv("LLDB_DEBUGSERVER_LOG_FILE");
582 if (env_debugserver_log_file)
583 {
584 ::snprintf (arg_cstr, sizeof(arg_cstr), "--log-file=%s", env_debugserver_log_file);
585 debugserver_args.AppendArgument(arg_cstr);
586 }
587
588 const char *env_debugserver_log_flags = getenv("LLDB_DEBUGSERVER_LOG_FLAGS");
589 if (env_debugserver_log_flags)
590 {
591 ::snprintf (arg_cstr, sizeof(arg_cstr), "--log-flags=%s", env_debugserver_log_flags);
592 debugserver_args.AppendArgument(arg_cstr);
593 }
594 // debugserver_args.AppendArgument("--log-file=/tmp/debugserver.txt");
595 // debugserver_args.AppendArgument("--log-flags=0x802e0e");
596
597 // We currently send down all arguments, attach pids, or attach
598 // process names in dedicated GDB server packets, so we don't need
599 // to pass them as arguments. This is currently because of all the
600 // things we need to setup prior to launching: the environment,
601 // current working dir, file actions, etc.
602 #if 0
603 // Now append the program arguments
604 if (inferior_argv)
605 {
606 // Terminate the debugserver args so we can now append the inferior args
607 debugserver_args.AppendArgument("--");
608
609 for (int i = 0; inferior_argv[i] != NULL; ++i)
610 debugserver_args.AppendArgument (inferior_argv[i]);
611 }
612 else if (attach_pid != LLDB_INVALID_PROCESS_ID)
613 {
614 ::snprintf (arg_cstr, sizeof(arg_cstr), "--attach=%u", attach_pid);
615 debugserver_args.AppendArgument (arg_cstr);
616 }
617 else if (attach_name && attach_name[0])
618 {
619 if (wait_for_launch)
620 debugserver_args.AppendArgument ("--waitfor");
621 else
622 debugserver_args.AppendArgument ("--attach");
623 debugserver_args.AppendArgument (attach_name);
624 }
625 #endif
626
627 // Close STDIN, STDOUT and STDERR. We might need to redirect them
628 // to "/dev/null" if we run into any problems.
629 // launch_info.AppendCloseFileAction (STDIN_FILENO);
630 // launch_info.AppendCloseFileAction (STDOUT_FILENO);
631 // launch_info.AppendCloseFileAction (STDERR_FILENO);
632
633 error = Host::LaunchProcess(launch_info);
634 }
635 else
636 {
637 error.SetErrorStringWithFormat ("unable to locate " DEBUGSERVER_BASENAME );
638 }
639 return error;
640 }
641
642 void
DumpHistory(Stream & strm)643 GDBRemoteCommunication::DumpHistory(Stream &strm)
644 {
645 m_history.Dump (strm);
646 }
647