LLDB mainline
GDBRemoteCommunicationServerPlatform.cpp
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1//===-- GDBRemoteCommunicationServerPlatform.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
10
11#include <cerrno>
12
13#include <chrono>
14#include <csignal>
15#include <cstring>
16#include <mutex>
17#include <optional>
18#include <sstream>
19#include <thread>
20
21#include "llvm/Support/FileSystem.h"
22#include "llvm/Support/JSON.h"
23#include "llvm/Support/Threading.h"
24
25#include "lldb/Host/Config.h"
28#include "lldb/Host/Host.h"
29#include "lldb/Host/HostInfo.h"
35#include "lldb/Utility/Log.h"
40
42
43using namespace lldb;
45using namespace lldb_private;
46
48 uint16_t max_port) {
49 for (; min_port < max_port; ++min_port)
51}
52
54 // Do not modify existing mappings
56}
57
58llvm::Expected<uint16_t>
60 if (m_port_map.empty())
61 return 0; // Bind to port zero and get a port, we didn't have any
62 // limitations
63
64 for (auto &pair : m_port_map) {
65 if (pair.second == LLDB_INVALID_PROCESS_ID) {
67 return pair.first;
68 }
69 }
70 return llvm::createStringError(llvm::inconvertibleErrorCode(),
71 "No free port found in port map");
72}
73
76 auto pos = m_port_map.find(port);
77 if (pos != m_port_map.end()) {
78 pos->second = pid;
79 return true;
80 }
81 return false;
82}
83
85 std::map<uint16_t, lldb::pid_t>::iterator pos = m_port_map.find(port);
86 if (pos != m_port_map.end()) {
87 pos->second = LLDB_INVALID_PROCESS_ID;
88 return true;
89 }
90 return false;
91}
92
95 if (!m_port_map.empty()) {
96 for (auto &pair : m_port_map) {
97 if (pair.second == pid) {
98 pair.second = LLDB_INVALID_PROCESS_ID;
99 return true;
100 }
101 }
102 }
103 return false;
104}
105
107 return m_port_map.empty();
108}
109
110// GDBRemoteCommunicationServerPlatform constructor
112 const Socket::SocketProtocol socket_protocol, const char *socket_scheme)
114 m_socket_protocol(socket_protocol), m_socket_scheme(socket_scheme),
117 m_pending_gdb_server.port = 0;
118
146
149 bool &interrupt, bool &quit) {
150 error.SetErrorString("interrupt received");
151 interrupt = true;
153 });
154}
155
156// Destructor
158 default;
159
161 const lldb_private::Args &args, std::string hostname, lldb::pid_t &pid,
162 std::optional<uint16_t> &port, std::string &socket_name) {
163 if (!port) {
164 llvm::Expected<uint16_t> available_port = m_port_map.GetNextAvailablePort();
165 if (available_port)
166 port = *available_port;
167 else
168 return Status(available_port.takeError());
169 }
170
171 // Spawn a new thread to accept the port that gets bound after binding to
172 // port 0 (zero).
173
174 // ignore the hostname send from the remote end, just use the ip address that
175 // we're currently communicating with as the hostname
176
177 // Spawn a debugserver and try to get the port it listens to.
178 ProcessLaunchInfo debugserver_launch_info;
179 if (hostname.empty())
180 hostname = "127.0.0.1";
181
183 LLDB_LOGF(log, "Launching debugserver with: %s:%u...", hostname.c_str(),
184 *port);
185
186 // Do not run in a new session so that it can not linger after the platform
187 // closes.
188 debugserver_launch_info.SetLaunchInSeparateProcessGroup(false);
189 debugserver_launch_info.SetMonitorProcessCallback(
191 this, std::placeholders::_1));
192
193 std::ostringstream url;
194// debugserver does not accept the URL scheme prefix.
195#if !defined(__APPLE__)
196 url << m_socket_scheme << "://";
197#endif
198 uint16_t *port_ptr = &*port;
200 std::string platform_uri = GetConnection()->GetURI();
201 std::optional<URI> parsed_uri = URI::Parse(platform_uri);
202 url << '[' << parsed_uri->hostname.str() << "]:" << *port;
203 } else {
204 socket_name = GetDomainSocketPath("gdbserver").GetPath();
205 url << socket_name;
206 port_ptr = nullptr;
207 }
208
210 url.str().c_str(), nullptr, debugserver_launch_info, port_ptr, &args, -1);
211
212 pid = debugserver_launch_info.GetProcessID();
214 std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
215 m_spawned_pids.insert(pid);
216 if (*port > 0)
218 } else {
219 if (*port > 0)
221 }
222 return error;
223}
224
227 StringExtractorGDBRemote &packet) {
228 // Spawn a local debugserver as a platform so we can then attach or launch a
229 // process...
230
232 LLDB_LOGF(log, "GDBRemoteCommunicationServerPlatform::%s() called",
233 __FUNCTION__);
234
235 ConnectionFileDescriptor file_conn;
236 std::string hostname;
237 packet.SetFilePos(::strlen("qLaunchGDBServer;"));
238 llvm::StringRef name;
239 llvm::StringRef value;
240 std::optional<uint16_t> port;
241 while (packet.GetNameColonValue(name, value)) {
242 if (name.equals("host"))
243 hostname = std::string(value);
244 else if (name.equals("port")) {
245 // Make the Optional valid so we can use its value
246 port = 0;
247 value.getAsInteger(0, *port);
248 }
249 }
250
251 lldb::pid_t debugserver_pid = LLDB_INVALID_PROCESS_ID;
252 std::string socket_name;
253 Status error =
254 LaunchGDBServer(Args(), hostname, debugserver_pid, port, socket_name);
255 if (error.Fail()) {
256 LLDB_LOGF(log,
257 "GDBRemoteCommunicationServerPlatform::%s() debugserver "
258 "launch failed: %s",
259 __FUNCTION__, error.AsCString());
260 return SendErrorResponse(9);
261 }
262
263 LLDB_LOGF(log,
264 "GDBRemoteCommunicationServerPlatform::%s() debugserver "
265 "launched successfully as pid %" PRIu64,
266 __FUNCTION__, debugserver_pid);
267
268 StreamGDBRemote response;
269 assert(port);
270 response.Printf("pid:%" PRIu64 ";port:%u;", debugserver_pid,
272 if (!socket_name.empty()) {
273 response.PutCString("socket_name:");
275 response.PutChar(';');
276 }
277
278 PacketResult packet_result = SendPacketNoLock(response.GetString());
279 if (packet_result != PacketResult::Success) {
280 if (debugserver_pid != LLDB_INVALID_PROCESS_ID)
281 Host::Kill(debugserver_pid, SIGINT);
282 }
283 return packet_result;
284}
285
288 StringExtractorGDBRemote &packet) {
289 namespace json = llvm::json;
290
292 return SendErrorResponse(4);
293
294 json::Object server{{"port", m_pending_gdb_server.port}};
295
296 if (!m_pending_gdb_server.socket_name.empty())
297 server.try_emplace("socket_name", m_pending_gdb_server.socket_name);
298
299 json::Array server_list;
300 server_list.push_back(std::move(server));
301
302 StreamGDBRemote response;
303 response.AsRawOstream() << std::move(server_list);
304
305 StreamGDBRemote escaped_response;
306 escaped_response.PutEscapedBytes(response.GetString().data(),
307 response.GetSize());
308 return SendPacketNoLock(escaped_response.GetString());
309}
310
313 StringExtractorGDBRemote &packet) {
314 packet.SetFilePos(::strlen("qKillSpawnedProcess:"));
315
317
318 // verify that we know anything about this pid. Scope for locker
319 {
320 std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
321 if (m_spawned_pids.find(pid) == m_spawned_pids.end()) {
322 // not a pid we know about
323 return SendErrorResponse(10);
324 }
325 }
326
327 // go ahead and attempt to kill the spawned process
329 return SendOKResponse();
330 else
331 return SendErrorResponse(11);
332}
333
335 // make sure we know about this process
336 {
337 std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
338 if (m_spawned_pids.find(pid) == m_spawned_pids.end())
339 return false;
340 }
341
342 // first try a SIGTERM (standard kill)
343 Host::Kill(pid, SIGTERM);
344
345 // check if that worked
346 for (size_t i = 0; i < 10; ++i) {
347 {
348 std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
349 if (m_spawned_pids.find(pid) == m_spawned_pids.end()) {
350 // it is now killed
351 return true;
352 }
353 }
354 std::this_thread::sleep_for(std::chrono::milliseconds(10));
355 }
356
357 {
358 std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
359 if (m_spawned_pids.find(pid) == m_spawned_pids.end())
360 return true;
361 }
362
363 // the launched process still lives. Now try killing it again, this time
364 // with an unblockable signal.
366
367 for (size_t i = 0; i < 10; ++i) {
368 {
369 std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
370 if (m_spawned_pids.find(pid) == m_spawned_pids.end()) {
371 // it is now killed
372 return true;
373 }
374 }
375 std::this_thread::sleep_for(std::chrono::milliseconds(10));
376 }
377
378 // check one more time after the final sleep
379 {
380 std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
381 if (m_spawned_pids.find(pid) == m_spawned_pids.end())
382 return true;
383 }
384
385 // no luck - the process still lives
386 return false;
387}
388
391 StringExtractorGDBRemote &packet) {
394
396 return SendErrorResponse(1);
397
398 ProcessInstanceInfo proc_info;
399 if (!Host::GetProcessInfo(pid, proc_info))
400 return SendErrorResponse(1);
401
402 StreamString response;
404 return SendPacketNoLock(response.GetString());
405}
406
409 StringExtractorGDBRemote &packet) {
410 packet.SetFilePos(::strlen("qPathComplete:"));
411 const bool only_dir = (packet.GetHexMaxU32(false, 0) == 1);
412 if (packet.GetChar() != ',')
413 return SendErrorResponse(85);
414 std::string path;
415 packet.GetHexByteString(path);
416
417 StringList matches;
419 if (only_dir)
420 CommandCompletions::DiskDirectories(path, matches, resolver);
421 else
422 CommandCompletions::DiskFiles(path, matches, resolver);
423
424 StreamString response;
425 response.PutChar('M');
426 llvm::StringRef separator;
427 std::sort(matches.begin(), matches.end());
428 for (const auto &match : matches) {
429 response << separator;
430 separator = ",";
431 // encode result strings into hex bytes to avoid unexpected error caused by
432 // special characters like '$'.
433 response.PutStringAsRawHex8(match.c_str());
434 }
435
436 return SendPacketNoLock(response.GetString());
437}
438
441 StringExtractorGDBRemote &packet) {
442
443 llvm::SmallString<64> cwd;
444 if (std::error_code ec = llvm::sys::fs::current_path(cwd))
445 return SendErrorResponse(ec.value());
446
447 StreamString response;
448 response.PutBytesAsRawHex8(cwd.data(), cwd.size());
449 return SendPacketNoLock(response.GetString());
450}
451
454 StringExtractorGDBRemote &packet) {
455 packet.SetFilePos(::strlen("QSetWorkingDir:"));
456 std::string path;
457 packet.GetHexByteString(path);
458
459 if (std::error_code ec = llvm::sys::fs::set_current_path(path))
460 return SendErrorResponse(ec.value());
461 return SendOKResponse();
462}
463
466 StringExtractorGDBRemote &packet) {
467 // NOTE: lldb should now be using qProcessInfo for process IDs. This path
468 // here
469 // should not be used. It is reporting process id instead of thread id. The
470 // correct answer doesn't seem to make much sense for lldb-platform.
471 // CONSIDER: flip to "unsupported".
473
474 StreamString response;
475 response.Printf("QC%" PRIx64, pid);
476
477 // If we launch a process and this GDB server is acting as a platform, then
478 // we need to clear the process launch state so we can start launching
479 // another process. In order to launch a process a bunch or packets need to
480 // be sent: environment packets, working directory, disable ASLR, and many
481 // more settings. When we launch a process we then need to know when to clear
482 // this information. Currently we are selecting the 'qC' packet as that
483 // packet which seems to make the most sense.
486 }
487
488 return SendPacketNoLock(response.GetString());
489}
490
493 StringExtractorGDBRemote &packet) {
494 StructuredData::Array signal_array;
495
496 lldb::UnixSignalsSP signals = UnixSignals::CreateForHost();
497 for (auto signo = signals->GetFirstSignalNumber();
499 signo = signals->GetNextSignalNumber(signo)) {
500 auto dictionary = std::make_shared<StructuredData::Dictionary>();
501
502 dictionary->AddIntegerItem("signo", signo);
503 dictionary->AddStringItem("name", signals->GetSignalAsCString(signo));
504
505 bool suppress, stop, notify;
506 signals->GetSignalInfo(signo, suppress, stop, notify);
507 dictionary->AddBooleanItem("suppress", suppress);
508 dictionary->AddBooleanItem("stop", stop);
509 dictionary->AddBooleanItem("notify", notify);
510
511 signal_array.Push(dictionary);
512 }
513
514 StreamString response;
515 signal_array.Dump(response);
516 return SendPacketNoLock(response.GetString());
517}
518
520 lldb::pid_t pid) {
521 std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
523 m_spawned_pids.erase(pid);
524}
525
528 return Status("%s: no process command line specified to launch",
529 __FUNCTION__);
530
531 // specify the process monitor if not already set. This should generally be
532 // what happens since we need to reap started processes.
536 std::placeholders::_1));
537
539 if (!error.Success()) {
540 fprintf(stderr, "%s: failed to launch executable %s", __FUNCTION__,
542 return error;
543 }
544
545 printf("Launched '%s' as process %" PRIu64 "...\n",
548
549 // add to list of spawned processes. On an lldb-gdbserver, we would expect
550 // there to be only one.
553 // add to spawned pids
554 std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
555 m_spawned_pids.insert(pid);
556 }
557
558 return error;
559}
560
562 m_port_map = std::move(port_map);
563}
564
566 static FileSpec g_domainsocket_dir;
567 static llvm::once_flag g_once_flag;
568
569 llvm::call_once(g_once_flag, []() {
570 const char *domainsocket_dir_env =
571 ::getenv("LLDB_DEBUGSERVER_DOMAINSOCKET_DIR");
572 if (domainsocket_dir_env != nullptr)
573 g_domainsocket_dir = FileSpec(domainsocket_dir_env);
574 else
575 g_domainsocket_dir = HostInfo::GetProcessTempDir();
576 });
577
578 return g_domainsocket_dir;
579}
580
583 llvm::SmallString<128> socket_path;
584 llvm::SmallString<128> socket_name(
585 (llvm::StringRef(prefix) + ".%%%%%%").str());
586
587 FileSpec socket_path_spec(GetDomainSocketDir());
588 socket_path_spec.AppendPathComponent(socket_name.c_str());
589
590 llvm::sys::fs::createUniqueFile(socket_path_spec.GetPath().c_str(),
591 socket_path);
592 return FileSpec(socket_path.c_str());
593}
594
596 m_port_offset = port_offset;
597}
598
600 lldb::pid_t pid, uint16_t port, const std::string &socket_name) {
603 m_pending_gdb_server.socket_name = socket_name;
604}
static llvm::raw_ostream & error(Stream &strm)
#define LLDB_LOGF(log,...)
Definition: Log.h:344
void SetFilePos(uint32_t idx)
uint32_t GetHexMaxU32(bool little_endian, uint32_t fail_value)
bool GetNameColonValue(llvm::StringRef &name, llvm::StringRef &value)
uint64_t GetU64(uint64_t fail_value, int base=0)
size_t GetHexByteString(std::string &str)
char GetChar(char fail_value='\0')
A command line argument class.
Definition: Args.h:33
size_t GetArgumentCount() const
Gets the number of arguments left in this command object.
Definition: Args.h:116
const char * GetArgumentAtIndex(size_t idx) const
Gets the NULL terminated C string argument pointer for the argument at index idx.
Definition: Args.cpp:264
static void DiskDirectories(CommandInterpreter &interpreter, CompletionRequest &request, SearchFilter *searcher)
static void DiskFiles(CommandInterpreter &interpreter, CompletionRequest &request, SearchFilter *searcher)
lldb_private::Connection * GetConnection()
Definition: Communication.h:87
virtual std::string GetURI()=0
Returns a URI that describes this connection object.
A file utility class.
Definition: FileSpec.h:56
void AppendPathComponent(llvm::StringRef component)
Definition: FileSpec.cpp:453
size_t GetPath(char *path, size_t max_path_length, bool denormalize=true) const
Extract the full path to the file.
Definition: FileSpec.cpp:366
static Status LaunchProcess(ProcessLaunchInfo &launch_info)
Launch the process specified in launch_info.
static bool GetProcessInfo(lldb::pid_t pid, ProcessInstanceInfo &proc_info)
static void Kill(lldb::pid_t pid, int signo)
lldb::pid_t GetProcessID() const
Definition: ProcessInfo.h:66
const Host::MonitorChildProcessCallback & GetMonitorProcessCallback() const
void SetMonitorProcessCallback(Host::MonitorChildProcessCallback callback)
void SetLaunchInSeparateProcessGroup(bool separate)
An error handling class.
Definition: Status.h:44
int PutEscapedBytes(const void *s, size_t src_len)
Output a block of data to the stream performing GDB-remote escaping.
Definition: GDBRemote.cpp:28
llvm::StringRef GetString() const
llvm::raw_ostream & AsRawOstream()
Returns a raw_ostream that forwards the data to this Stream object.
Definition: Stream.h:357
size_t PutStringAsRawHex8(llvm::StringRef s)
Definition: Stream.cpp:383
size_t Printf(const char *format,...) __attribute__((format(printf
Output printf formatted output to the stream.
Definition: Stream.cpp:107
size_t PutCString(llvm::StringRef cstr)
Output a C string to the stream.
Definition: Stream.cpp:63
size_t PutChar(char ch)
Definition: Stream.cpp:104
size_t PutBytesAsRawHex8(const void *src, size_t src_len, lldb::ByteOrder src_byte_order=lldb::eByteOrderInvalid, lldb::ByteOrder dst_byte_order=lldb::eByteOrderInvalid)
Definition: Stream.cpp:356
void Push(const ObjectSP &item)
void Dump(lldb_private::Stream &s, bool pretty_print=true) const
static lldb::UnixSignalsSP CreateForHost()
Definition: UnixSignals.cpp:57
void RegisterMemberFunctionHandler(StringExtractorGDBRemote::ServerPacketType packet_type, PacketResult(T::*handler)(StringExtractorGDBRemote &packet))
static void CreateProcessInfoResponse_DebugServerStyle(const ProcessInstanceInfo &proc_info, StreamString &response)
Status LaunchGDBServer(const lldb_private::Args &args, std::string hostname, lldb::pid_t &pid, std::optional< uint16_t > &port, std::string &socket_name)
void SetPendingGdbServer(lldb::pid_t pid, uint16_t port, const std::string &socket_name)
struct lldb_private::process_gdb_remote::GDBRemoteCommunicationServerPlatform::@76 m_pending_gdb_server
GDBRemoteCommunicationServerPlatform(const Socket::SocketProtocol socket_protocol, const char *socket_scheme)
Status LaunchProcess() override
Launch a process with the current launch settings.
void RegisterPacketHandler(StringExtractorGDBRemote::ServerPacketType packet_type, PacketHandler handler)
Status StartDebugserverProcess(const char *url, Platform *platform, ProcessLaunchInfo &launch_info, uint16_t *port, const Args *inferior_args, int pass_comm_fd)
#define LLDB_INVALID_SIGNAL_NUMBER
Definition: lldb-defines.h:84
#define LLDB_INVALID_PROCESS_ID
Definition: lldb-defines.h:81
A class that represents a running process on the host machine.
Log * GetLog(Cat mask)
Retrieve the Log object for the channel associated with the given log enum.
Definition: Log.h:309
Definition: SBAddress.h:15
uint64_t pid_t
Definition: lldb-types.h:85
static std::optional< URI > Parse(llvm::StringRef uri)
Definition: UriParser.cpp:28
#define SIGKILL