1 //===-- PlatformRemoteGDBServer.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 "PlatformRemoteGDBServer.h"
10 #include "lldb/Host/Config.h"
11 
12 #include "lldb/Breakpoint/BreakpointLocation.h"
13 #include "lldb/Core/Debugger.h"
14 #include "lldb/Core/Module.h"
15 #include "lldb/Core/ModuleList.h"
16 #include "lldb/Core/ModuleSpec.h"
17 #include "lldb/Core/PluginManager.h"
18 #include "lldb/Core/StreamFile.h"
19 #include "lldb/Host/ConnectionFileDescriptor.h"
20 #include "lldb/Host/Host.h"
21 #include "lldb/Host/HostInfo.h"
22 #include "lldb/Host/PosixApi.h"
23 #include "lldb/Target/Process.h"
24 #include "lldb/Target/Target.h"
25 #include "lldb/Utility/FileSpec.h"
26 #include "lldb/Utility/LLDBLog.h"
27 #include "lldb/Utility/Log.h"
28 #include "lldb/Utility/ProcessInfo.h"
29 #include "lldb/Utility/Status.h"
30 #include "lldb/Utility/StreamString.h"
31 #include "lldb/Utility/UriParser.h"
32 
33 #include "Plugins/Process/Utility/GDBRemoteSignals.h"
34 #include "Plugins/Process/gdb-remote/ProcessGDBRemote.h"
35 
36 using namespace lldb;
37 using namespace lldb_private;
38 using namespace lldb_private::platform_gdb_server;
39 
40 LLDB_PLUGIN_DEFINE_ADV(PlatformRemoteGDBServer, PlatformGDB)
41 
42 static bool g_initialized = false;
43 
44 void PlatformRemoteGDBServer::Initialize() {
45   Platform::Initialize();
46 
47   if (!g_initialized) {
48     g_initialized = true;
49     PluginManager::RegisterPlugin(
50         PlatformRemoteGDBServer::GetPluginNameStatic(),
51         PlatformRemoteGDBServer::GetDescriptionStatic(),
52         PlatformRemoteGDBServer::CreateInstance);
53   }
54 }
55 
56 void PlatformRemoteGDBServer::Terminate() {
57   if (g_initialized) {
58     g_initialized = false;
59     PluginManager::UnregisterPlugin(PlatformRemoteGDBServer::CreateInstance);
60   }
61 
62   Platform::Terminate();
63 }
64 
65 PlatformSP PlatformRemoteGDBServer::CreateInstance(bool force,
66                                                    const ArchSpec *arch) {
67   bool create = force;
68   if (!create) {
69     create = !arch->TripleVendorWasSpecified() && !arch->TripleOSWasSpecified();
70   }
71   if (create)
72     return PlatformSP(new PlatformRemoteGDBServer());
73   return PlatformSP();
74 }
75 
76 llvm::StringRef PlatformRemoteGDBServer::GetDescriptionStatic() {
77   return "A platform that uses the GDB remote protocol as the communication "
78          "transport.";
79 }
80 
81 llvm::StringRef PlatformRemoteGDBServer::GetDescription() {
82   if (m_platform_description.empty()) {
83     if (IsConnected()) {
84       // Send the get description packet
85     }
86   }
87 
88   if (!m_platform_description.empty())
89     return m_platform_description.c_str();
90   return GetDescriptionStatic();
91 }
92 
93 bool PlatformRemoteGDBServer::GetModuleSpec(const FileSpec &module_file_spec,
94                                             const ArchSpec &arch,
95                                             ModuleSpec &module_spec) {
96   Log *log = GetLog(LLDBLog::Platform);
97 
98   const auto module_path = module_file_spec.GetPath(false);
99 
100   if (!m_gdb_client_up ||
101       !m_gdb_client_up->GetModuleInfo(module_file_spec, arch, module_spec)) {
102     LLDB_LOGF(
103         log,
104         "PlatformRemoteGDBServer::%s - failed to get module info for %s:%s",
105         __FUNCTION__, module_path.c_str(),
106         arch.GetTriple().getTriple().c_str());
107     return false;
108   }
109 
110   if (log) {
111     StreamString stream;
112     module_spec.Dump(stream);
113     LLDB_LOGF(log,
114               "PlatformRemoteGDBServer::%s - got module info for (%s:%s) : %s",
115               __FUNCTION__, module_path.c_str(),
116               arch.GetTriple().getTriple().c_str(), stream.GetData());
117   }
118 
119   return true;
120 }
121 
122 Status PlatformRemoteGDBServer::GetFileWithUUID(const FileSpec &platform_file,
123                                                 const UUID *uuid_ptr,
124                                                 FileSpec &local_file) {
125   // Default to the local case
126   local_file = platform_file;
127   return Status();
128 }
129 
130 /// Default Constructor
131 PlatformRemoteGDBServer::PlatformRemoteGDBServer()
132     : Platform(/*is_host=*/false) {}
133 
134 /// Destructor.
135 ///
136 /// The destructor is virtual since this class is designed to be
137 /// inherited from by the plug-in instance.
138 PlatformRemoteGDBServer::~PlatformRemoteGDBServer() = default;
139 
140 size_t PlatformRemoteGDBServer::GetSoftwareBreakpointTrapOpcode(
141     Target &target, BreakpointSite *bp_site) {
142   // This isn't needed if the z/Z packets are supported in the GDB remote
143   // server. But we might need a packet to detect this.
144   return 0;
145 }
146 
147 bool PlatformRemoteGDBServer::GetRemoteOSVersion() {
148   if (m_gdb_client_up)
149     m_os_version = m_gdb_client_up->GetOSVersion();
150   return !m_os_version.empty();
151 }
152 
153 llvm::Optional<std::string> PlatformRemoteGDBServer::GetRemoteOSBuildString() {
154   if (!m_gdb_client_up)
155     return llvm::None;
156   return m_gdb_client_up->GetOSBuildString();
157 }
158 
159 llvm::Optional<std::string>
160 PlatformRemoteGDBServer::GetRemoteOSKernelDescription() {
161   if (!m_gdb_client_up)
162     return llvm::None;
163   return m_gdb_client_up->GetOSKernelDescription();
164 }
165 
166 // Remote Platform subclasses need to override this function
167 ArchSpec PlatformRemoteGDBServer::GetRemoteSystemArchitecture() {
168   if (!m_gdb_client_up)
169     return ArchSpec();
170   return m_gdb_client_up->GetSystemArchitecture();
171 }
172 
173 FileSpec PlatformRemoteGDBServer::GetRemoteWorkingDirectory() {
174   if (IsConnected()) {
175     Log *log = GetLog(LLDBLog::Platform);
176     FileSpec working_dir;
177     if (m_gdb_client_up->GetWorkingDir(working_dir) && log)
178       LLDB_LOGF(log,
179                 "PlatformRemoteGDBServer::GetRemoteWorkingDirectory() -> '%s'",
180                 working_dir.GetPath().c_str());
181     return working_dir;
182   } else {
183     return Platform::GetRemoteWorkingDirectory();
184   }
185 }
186 
187 bool PlatformRemoteGDBServer::SetRemoteWorkingDirectory(
188     const FileSpec &working_dir) {
189   if (IsConnected()) {
190     // Clear the working directory it case it doesn't get set correctly. This
191     // will for use to re-read it
192     Log *log = GetLog(LLDBLog::Platform);
193     LLDB_LOGF(log, "PlatformRemoteGDBServer::SetRemoteWorkingDirectory('%s')",
194               working_dir.GetPath().c_str());
195     return m_gdb_client_up->SetWorkingDir(working_dir) == 0;
196   } else
197     return Platform::SetRemoteWorkingDirectory(working_dir);
198 }
199 
200 bool PlatformRemoteGDBServer::IsConnected() const {
201   if (m_gdb_client_up) {
202     assert(m_gdb_client_up->IsConnected());
203     return true;
204   }
205   return false;
206 }
207 
208 Status PlatformRemoteGDBServer::ConnectRemote(Args &args) {
209   Status error;
210   if (IsConnected()) {
211     error.SetErrorStringWithFormat("the platform is already connected to '%s', "
212                                    "execute 'platform disconnect' to close the "
213                                    "current connection",
214                                    GetHostname());
215     return error;
216   }
217 
218   if (args.GetArgumentCount() != 1) {
219     error.SetErrorString(
220         "\"platform connect\" takes a single argument: <connect-url>");
221     return error;
222   }
223 
224   const char *url = args.GetArgumentAtIndex(0);
225   if (!url)
226     return Status("URL is null.");
227 
228   llvm::Optional<URI> parsed_url = URI::Parse(url);
229   if (!parsed_url)
230     return Status("Invalid URL: %s", url);
231 
232   // We're going to reuse the hostname when we connect to the debugserver.
233   m_platform_scheme = parsed_url->scheme.str();
234   m_platform_hostname = parsed_url->hostname.str();
235 
236   auto client_up =
237       std::make_unique<process_gdb_remote::GDBRemoteCommunicationClient>();
238   client_up->SetPacketTimeout(
239       process_gdb_remote::ProcessGDBRemote::GetPacketTimeout());
240   client_up->SetConnection(std::make_unique<ConnectionFileDescriptor>());
241   if (repro::Generator *g = repro::Reproducer::Instance().GetGenerator()) {
242     repro::GDBRemoteProvider &provider =
243         g->GetOrCreate<repro::GDBRemoteProvider>();
244     client_up->SetPacketRecorder(provider.GetNewPacketRecorder());
245   }
246   client_up->Connect(url, &error);
247 
248   if (error.Fail())
249     return error;
250 
251   if (client_up->HandshakeWithServer(&error)) {
252     m_gdb_client_up = std::move(client_up);
253     m_gdb_client_up->GetHostInfo();
254     // If a working directory was set prior to connecting, send it down
255     // now.
256     if (m_working_dir)
257       m_gdb_client_up->SetWorkingDir(m_working_dir);
258 
259     m_supported_architectures.clear();
260     ArchSpec remote_arch = m_gdb_client_up->GetSystemArchitecture();
261     if (remote_arch) {
262       m_supported_architectures.push_back(remote_arch);
263       if (remote_arch.GetTriple().isArch64Bit())
264         m_supported_architectures.push_back(
265             ArchSpec(remote_arch.GetTriple().get32BitArchVariant()));
266     }
267   } else {
268     client_up->Disconnect();
269     if (error.Success())
270       error.SetErrorString("handshake failed");
271   }
272   return error;
273 }
274 
275 Status PlatformRemoteGDBServer::DisconnectRemote() {
276   Status error;
277   m_gdb_client_up.reset();
278   m_remote_signals_sp.reset();
279   return error;
280 }
281 
282 const char *PlatformRemoteGDBServer::GetHostname() {
283   if (m_gdb_client_up)
284     m_gdb_client_up->GetHostname(m_hostname);
285   if (m_hostname.empty())
286     return nullptr;
287   return m_hostname.c_str();
288 }
289 
290 llvm::Optional<std::string>
291 PlatformRemoteGDBServer::DoGetUserName(UserIDResolver::id_t uid) {
292   std::string name;
293   if (m_gdb_client_up && m_gdb_client_up->GetUserName(uid, name))
294     return std::move(name);
295   return llvm::None;
296 }
297 
298 llvm::Optional<std::string>
299 PlatformRemoteGDBServer::DoGetGroupName(UserIDResolver::id_t gid) {
300   std::string name;
301   if (m_gdb_client_up && m_gdb_client_up->GetGroupName(gid, name))
302     return std::move(name);
303   return llvm::None;
304 }
305 
306 uint32_t PlatformRemoteGDBServer::FindProcesses(
307     const ProcessInstanceInfoMatch &match_info,
308     ProcessInstanceInfoList &process_infos) {
309   if (m_gdb_client_up)
310     return m_gdb_client_up->FindProcesses(match_info, process_infos);
311   return 0;
312 }
313 
314 bool PlatformRemoteGDBServer::GetProcessInfo(
315     lldb::pid_t pid, ProcessInstanceInfo &process_info) {
316   if (m_gdb_client_up)
317     return m_gdb_client_up->GetProcessInfo(pid, process_info);
318   return false;
319 }
320 
321 Status PlatformRemoteGDBServer::LaunchProcess(ProcessLaunchInfo &launch_info) {
322   Log *log = GetLog(LLDBLog::Platform);
323   Status error;
324 
325   LLDB_LOGF(log, "PlatformRemoteGDBServer::%s() called", __FUNCTION__);
326 
327   if (!IsConnected())
328     return Status("Not connected.");
329   auto num_file_actions = launch_info.GetNumFileActions();
330   for (decltype(num_file_actions) i = 0; i < num_file_actions; ++i) {
331     const auto file_action = launch_info.GetFileActionAtIndex(i);
332     if (file_action->GetAction() != FileAction::eFileActionOpen)
333       continue;
334     switch (file_action->GetFD()) {
335     case STDIN_FILENO:
336       m_gdb_client_up->SetSTDIN(file_action->GetFileSpec());
337       break;
338     case STDOUT_FILENO:
339       m_gdb_client_up->SetSTDOUT(file_action->GetFileSpec());
340       break;
341     case STDERR_FILENO:
342       m_gdb_client_up->SetSTDERR(file_action->GetFileSpec());
343       break;
344     }
345   }
346 
347   m_gdb_client_up->SetDisableASLR(
348       launch_info.GetFlags().Test(eLaunchFlagDisableASLR));
349   m_gdb_client_up->SetDetachOnError(
350       launch_info.GetFlags().Test(eLaunchFlagDetachOnError));
351 
352   FileSpec working_dir = launch_info.GetWorkingDirectory();
353   if (working_dir) {
354     m_gdb_client_up->SetWorkingDir(working_dir);
355   }
356 
357   // Send the environment and the program + arguments after we connect
358   m_gdb_client_up->SendEnvironment(launch_info.GetEnvironment());
359 
360   ArchSpec arch_spec = launch_info.GetArchitecture();
361   const char *arch_triple = arch_spec.GetTriple().str().c_str();
362 
363   m_gdb_client_up->SendLaunchArchPacket(arch_triple);
364   LLDB_LOGF(
365       log,
366       "PlatformRemoteGDBServer::%s() set launch architecture triple to '%s'",
367       __FUNCTION__, arch_triple ? arch_triple : "<NULL>");
368 
369   int arg_packet_err;
370   {
371     // Scope for the scoped timeout object
372     process_gdb_remote::GDBRemoteCommunication::ScopedTimeout timeout(
373         *m_gdb_client_up, std::chrono::seconds(5));
374     arg_packet_err = m_gdb_client_up->SendArgumentsPacket(launch_info);
375   }
376 
377   if (arg_packet_err == 0) {
378     std::string error_str;
379     if (m_gdb_client_up->GetLaunchSuccess(error_str)) {
380       const auto pid = m_gdb_client_up->GetCurrentProcessID(false);
381       if (pid != LLDB_INVALID_PROCESS_ID) {
382         launch_info.SetProcessID(pid);
383         LLDB_LOGF(log,
384                   "PlatformRemoteGDBServer::%s() pid %" PRIu64
385                   " launched successfully",
386                   __FUNCTION__, pid);
387       } else {
388         LLDB_LOGF(log,
389                   "PlatformRemoteGDBServer::%s() launch succeeded but we "
390                   "didn't get a valid process id back!",
391                   __FUNCTION__);
392         error.SetErrorString("failed to get PID");
393       }
394     } else {
395       error.SetErrorString(error_str.c_str());
396       LLDB_LOGF(log, "PlatformRemoteGDBServer::%s() launch failed: %s",
397                 __FUNCTION__, error.AsCString());
398     }
399   } else {
400     error.SetErrorStringWithFormat("'A' packet returned an error: %i",
401                                    arg_packet_err);
402   }
403   return error;
404 }
405 
406 Status PlatformRemoteGDBServer::KillProcess(const lldb::pid_t pid) {
407   if (!KillSpawnedProcess(pid))
408     return Status("failed to kill remote spawned process");
409   return Status();
410 }
411 
412 lldb::ProcessSP
413 PlatformRemoteGDBServer::DebugProcess(ProcessLaunchInfo &launch_info,
414                                       Debugger &debugger, Target &target,
415                                       Status &error) {
416   lldb::ProcessSP process_sp;
417   if (IsRemote()) {
418     if (IsConnected()) {
419       lldb::pid_t debugserver_pid = LLDB_INVALID_PROCESS_ID;
420       std::string connect_url;
421       if (!LaunchGDBServer(debugserver_pid, connect_url)) {
422         error.SetErrorStringWithFormat("unable to launch a GDB server on '%s'",
423                                        GetHostname());
424       } else {
425         // The darwin always currently uses the GDB remote debugger plug-in
426         // so even when debugging locally we are debugging remotely!
427         process_sp = target.CreateProcess(launch_info.GetListener(),
428                                           "gdb-remote", nullptr, true);
429 
430         if (process_sp) {
431           process_sp->HijackProcessEvents(launch_info.GetHijackListener());
432 
433           error = process_sp->ConnectRemote(connect_url.c_str());
434           // Retry the connect remote one time...
435           if (error.Fail())
436             error = process_sp->ConnectRemote(connect_url.c_str());
437           if (error.Success())
438             error = process_sp->Launch(launch_info);
439           else if (debugserver_pid != LLDB_INVALID_PROCESS_ID) {
440             printf("error: connect remote failed (%s)\n", error.AsCString());
441             KillSpawnedProcess(debugserver_pid);
442           }
443         }
444       }
445     } else {
446       error.SetErrorString("not connected to remote gdb server");
447     }
448   }
449   return process_sp;
450 }
451 
452 bool PlatformRemoteGDBServer::LaunchGDBServer(lldb::pid_t &pid,
453                                               std::string &connect_url) {
454   assert(IsConnected());
455 
456   ArchSpec remote_arch = GetRemoteSystemArchitecture();
457   llvm::Triple &remote_triple = remote_arch.GetTriple();
458 
459   uint16_t port = 0;
460   std::string socket_name;
461   bool launch_result = false;
462   if (remote_triple.getVendor() == llvm::Triple::Apple &&
463       remote_triple.getOS() == llvm::Triple::IOS) {
464     // When remote debugging to iOS, we use a USB mux that always talks to
465     // localhost, so we will need the remote debugserver to accept connections
466     // only from localhost, no matter what our current hostname is
467     launch_result =
468         m_gdb_client_up->LaunchGDBServer("127.0.0.1", pid, port, socket_name);
469   } else {
470     // All other hosts should use their actual hostname
471     launch_result =
472         m_gdb_client_up->LaunchGDBServer(nullptr, pid, port, socket_name);
473   }
474 
475   if (!launch_result)
476     return false;
477 
478   connect_url =
479       MakeGdbServerUrl(m_platform_scheme, m_platform_hostname, port,
480                        (socket_name.empty()) ? nullptr : socket_name.c_str());
481   return true;
482 }
483 
484 bool PlatformRemoteGDBServer::KillSpawnedProcess(lldb::pid_t pid) {
485   assert(IsConnected());
486   return m_gdb_client_up->KillSpawnedProcess(pid);
487 }
488 
489 lldb::ProcessSP PlatformRemoteGDBServer::Attach(
490     ProcessAttachInfo &attach_info, Debugger &debugger,
491     Target *target, // Can be NULL, if NULL create a new target, else use
492                     // existing one
493     Status &error) {
494   lldb::ProcessSP process_sp;
495   if (IsRemote()) {
496     if (IsConnected()) {
497       lldb::pid_t debugserver_pid = LLDB_INVALID_PROCESS_ID;
498       std::string connect_url;
499       if (!LaunchGDBServer(debugserver_pid, connect_url)) {
500         error.SetErrorStringWithFormat("unable to launch a GDB server on '%s'",
501                                        GetHostname());
502       } else {
503         if (target == nullptr) {
504           TargetSP new_target_sp;
505 
506           error = debugger.GetTargetList().CreateTarget(
507               debugger, "", "", eLoadDependentsNo, nullptr, new_target_sp);
508           target = new_target_sp.get();
509         } else
510           error.Clear();
511 
512         if (target && error.Success()) {
513           // The darwin always currently uses the GDB remote debugger plug-in
514           // so even when debugging locally we are debugging remotely!
515           process_sp =
516               target->CreateProcess(attach_info.GetListenerForProcess(debugger),
517                                     "gdb-remote", nullptr, true);
518           if (process_sp) {
519             error = process_sp->ConnectRemote(connect_url.c_str());
520             if (error.Success()) {
521               ListenerSP listener_sp = attach_info.GetHijackListener();
522               if (listener_sp)
523                 process_sp->HijackProcessEvents(listener_sp);
524               error = process_sp->Attach(attach_info);
525             }
526 
527             if (error.Fail() && debugserver_pid != LLDB_INVALID_PROCESS_ID) {
528               KillSpawnedProcess(debugserver_pid);
529             }
530           }
531         }
532       }
533     } else {
534       error.SetErrorString("not connected to remote gdb server");
535     }
536   }
537   return process_sp;
538 }
539 
540 Status PlatformRemoteGDBServer::MakeDirectory(const FileSpec &file_spec,
541                                               uint32_t mode) {
542   if (!IsConnected())
543     return Status("Not connected.");
544   Status error = m_gdb_client_up->MakeDirectory(file_spec, mode);
545   Log *log = GetLog(LLDBLog::Platform);
546   LLDB_LOGF(log,
547             "PlatformRemoteGDBServer::MakeDirectory(path='%s', mode=%o) "
548             "error = %u (%s)",
549             file_spec.GetPath().c_str(), mode, error.GetError(),
550             error.AsCString());
551   return error;
552 }
553 
554 Status PlatformRemoteGDBServer::GetFilePermissions(const FileSpec &file_spec,
555                                                    uint32_t &file_permissions) {
556   if (!IsConnected())
557     return Status("Not connected.");
558   Status error =
559       m_gdb_client_up->GetFilePermissions(file_spec, file_permissions);
560   Log *log = GetLog(LLDBLog::Platform);
561   LLDB_LOGF(log,
562             "PlatformRemoteGDBServer::GetFilePermissions(path='%s', "
563             "file_permissions=%o) error = %u (%s)",
564             file_spec.GetPath().c_str(), file_permissions, error.GetError(),
565             error.AsCString());
566   return error;
567 }
568 
569 Status PlatformRemoteGDBServer::SetFilePermissions(const FileSpec &file_spec,
570                                                    uint32_t file_permissions) {
571   if (!IsConnected())
572     return Status("Not connected.");
573   Status error =
574       m_gdb_client_up->SetFilePermissions(file_spec, file_permissions);
575   Log *log = GetLog(LLDBLog::Platform);
576   LLDB_LOGF(log,
577             "PlatformRemoteGDBServer::SetFilePermissions(path='%s', "
578             "file_permissions=%o) error = %u (%s)",
579             file_spec.GetPath().c_str(), file_permissions, error.GetError(),
580             error.AsCString());
581   return error;
582 }
583 
584 lldb::user_id_t PlatformRemoteGDBServer::OpenFile(const FileSpec &file_spec,
585                                                   File::OpenOptions flags,
586                                                   uint32_t mode,
587                                                   Status &error) {
588   if (IsConnected())
589     return m_gdb_client_up->OpenFile(file_spec, flags, mode, error);
590   return LLDB_INVALID_UID;
591 }
592 
593 bool PlatformRemoteGDBServer::CloseFile(lldb::user_id_t fd, Status &error) {
594   if (IsConnected())
595     return m_gdb_client_up->CloseFile(fd, error);
596   error = Status("Not connected.");
597   return false;
598 }
599 
600 lldb::user_id_t
601 PlatformRemoteGDBServer::GetFileSize(const FileSpec &file_spec) {
602   if (IsConnected())
603     return m_gdb_client_up->GetFileSize(file_spec);
604   return LLDB_INVALID_UID;
605 }
606 
607 void PlatformRemoteGDBServer::AutoCompleteDiskFileOrDirectory(
608     CompletionRequest &request, bool only_dir) {
609   if (IsConnected())
610     m_gdb_client_up->AutoCompleteDiskFileOrDirectory(request, only_dir);
611 }
612 
613 uint64_t PlatformRemoteGDBServer::ReadFile(lldb::user_id_t fd, uint64_t offset,
614                                            void *dst, uint64_t dst_len,
615                                            Status &error) {
616   if (IsConnected())
617     return m_gdb_client_up->ReadFile(fd, offset, dst, dst_len, error);
618   error = Status("Not connected.");
619   return 0;
620 }
621 
622 uint64_t PlatformRemoteGDBServer::WriteFile(lldb::user_id_t fd, uint64_t offset,
623                                             const void *src, uint64_t src_len,
624                                             Status &error) {
625   if (IsConnected())
626     return m_gdb_client_up->WriteFile(fd, offset, src, src_len, error);
627   error = Status("Not connected.");
628   return 0;
629 }
630 
631 Status PlatformRemoteGDBServer::PutFile(const FileSpec &source,
632                                         const FileSpec &destination,
633                                         uint32_t uid, uint32_t gid) {
634   return Platform::PutFile(source, destination, uid, gid);
635 }
636 
637 Status PlatformRemoteGDBServer::CreateSymlink(
638     const FileSpec &src, // The name of the link is in src
639     const FileSpec &dst) // The symlink points to dst
640 {
641   if (!IsConnected())
642     return Status("Not connected.");
643   Status error = m_gdb_client_up->CreateSymlink(src, dst);
644   Log *log = GetLog(LLDBLog::Platform);
645   LLDB_LOGF(log,
646             "PlatformRemoteGDBServer::CreateSymlink(src='%s', dst='%s') "
647             "error = %u (%s)",
648             src.GetPath().c_str(), dst.GetPath().c_str(), error.GetError(),
649             error.AsCString());
650   return error;
651 }
652 
653 Status PlatformRemoteGDBServer::Unlink(const FileSpec &file_spec) {
654   if (!IsConnected())
655     return Status("Not connected.");
656   Status error = m_gdb_client_up->Unlink(file_spec);
657   Log *log = GetLog(LLDBLog::Platform);
658   LLDB_LOGF(log, "PlatformRemoteGDBServer::Unlink(path='%s') error = %u (%s)",
659             file_spec.GetPath().c_str(), error.GetError(), error.AsCString());
660   return error;
661 }
662 
663 bool PlatformRemoteGDBServer::GetFileExists(const FileSpec &file_spec) {
664   if (IsConnected())
665     return m_gdb_client_up->GetFileExists(file_spec);
666   return false;
667 }
668 
669 Status PlatformRemoteGDBServer::RunShellCommand(
670     llvm::StringRef shell, llvm::StringRef command,
671     const FileSpec &
672         working_dir, // Pass empty FileSpec to use the current working directory
673     int *status_ptr, // Pass NULL if you don't want the process exit status
674     int *signo_ptr,  // Pass NULL if you don't want the signal that caused the
675                      // process to exit
676     std::string
677         *command_output, // Pass NULL if you don't want the command output
678     const Timeout<std::micro> &timeout) {
679   if (!IsConnected())
680     return Status("Not connected.");
681   return m_gdb_client_up->RunShellCommand(command, working_dir, status_ptr,
682                                           signo_ptr, command_output, timeout);
683 }
684 
685 void PlatformRemoteGDBServer::CalculateTrapHandlerSymbolNames() {
686   m_trap_handlers.push_back(ConstString("_sigtramp"));
687 }
688 
689 const UnixSignalsSP &PlatformRemoteGDBServer::GetRemoteUnixSignals() {
690   if (!IsConnected())
691     return Platform::GetRemoteUnixSignals();
692 
693   if (m_remote_signals_sp)
694     return m_remote_signals_sp;
695 
696   // If packet not implemented or JSON failed to parse, we'll guess the signal
697   // set based on the remote architecture.
698   m_remote_signals_sp = UnixSignals::Create(GetRemoteSystemArchitecture());
699 
700   StringExtractorGDBRemote response;
701   auto result =
702       m_gdb_client_up->SendPacketAndWaitForResponse("jSignalsInfo", response);
703 
704   if (result != decltype(result)::Success ||
705       response.GetResponseType() != response.eResponse)
706     return m_remote_signals_sp;
707 
708   auto object_sp =
709       StructuredData::ParseJSON(std::string(response.GetStringRef()));
710   if (!object_sp || !object_sp->IsValid())
711     return m_remote_signals_sp;
712 
713   auto array_sp = object_sp->GetAsArray();
714   if (!array_sp || !array_sp->IsValid())
715     return m_remote_signals_sp;
716 
717   auto remote_signals_sp = std::make_shared<lldb_private::GDBRemoteSignals>();
718 
719   bool done = array_sp->ForEach(
720       [&remote_signals_sp](StructuredData::Object *object) -> bool {
721         if (!object || !object->IsValid())
722           return false;
723 
724         auto dict = object->GetAsDictionary();
725         if (!dict || !dict->IsValid())
726           return false;
727 
728         // Signal number and signal name are required.
729         int signo;
730         if (!dict->GetValueForKeyAsInteger("signo", signo))
731           return false;
732 
733         llvm::StringRef name;
734         if (!dict->GetValueForKeyAsString("name", name))
735           return false;
736 
737         // We can live without short_name, description, etc.
738         bool suppress{false};
739         auto object_sp = dict->GetValueForKey("suppress");
740         if (object_sp && object_sp->IsValid())
741           suppress = object_sp->GetBooleanValue();
742 
743         bool stop{false};
744         object_sp = dict->GetValueForKey("stop");
745         if (object_sp && object_sp->IsValid())
746           stop = object_sp->GetBooleanValue();
747 
748         bool notify{false};
749         object_sp = dict->GetValueForKey("notify");
750         if (object_sp && object_sp->IsValid())
751           notify = object_sp->GetBooleanValue();
752 
753         std::string description;
754         object_sp = dict->GetValueForKey("description");
755         if (object_sp && object_sp->IsValid())
756           description = std::string(object_sp->GetStringValue());
757 
758         remote_signals_sp->AddSignal(signo, name.str().c_str(), suppress, stop,
759                                      notify, description.c_str());
760         return true;
761       });
762 
763   if (done)
764     m_remote_signals_sp = std::move(remote_signals_sp);
765 
766   return m_remote_signals_sp;
767 }
768 
769 std::string PlatformRemoteGDBServer::MakeGdbServerUrl(
770     const std::string &platform_scheme, const std::string &platform_hostname,
771     uint16_t port, const char *socket_name) {
772   const char *override_scheme =
773       getenv("LLDB_PLATFORM_REMOTE_GDB_SERVER_SCHEME");
774   const char *override_hostname =
775       getenv("LLDB_PLATFORM_REMOTE_GDB_SERVER_HOSTNAME");
776   const char *port_offset_c_str =
777       getenv("LLDB_PLATFORM_REMOTE_GDB_SERVER_PORT_OFFSET");
778   int port_offset = port_offset_c_str ? ::atoi(port_offset_c_str) : 0;
779 
780   return MakeUrl(override_scheme ? override_scheme : platform_scheme.c_str(),
781                  override_hostname ? override_hostname
782                                    : platform_hostname.c_str(),
783                  port + port_offset, socket_name);
784 }
785 
786 std::string PlatformRemoteGDBServer::MakeUrl(const char *scheme,
787                                              const char *hostname,
788                                              uint16_t port, const char *path) {
789   StreamString result;
790   result.Printf("%s://[%s]", scheme, hostname);
791   if (port != 0)
792     result.Printf(":%u", port);
793   if (path)
794     result.Write(path, strlen(path));
795   return std::string(result.GetString());
796 }
797 
798 size_t PlatformRemoteGDBServer::ConnectToWaitingProcesses(Debugger &debugger,
799                                                           Status &error) {
800   std::vector<std::string> connection_urls;
801   GetPendingGdbServerList(connection_urls);
802 
803   for (size_t i = 0; i < connection_urls.size(); ++i) {
804     ConnectProcess(connection_urls[i].c_str(), "gdb-remote", debugger, nullptr, error);
805     if (error.Fail())
806       return i; // We already connected to i process succsessfully
807   }
808   return connection_urls.size();
809 }
810 
811 size_t PlatformRemoteGDBServer::GetPendingGdbServerList(
812     std::vector<std::string> &connection_urls) {
813   std::vector<std::pair<uint16_t, std::string>> remote_servers;
814   if (!IsConnected())
815     return 0;
816   m_gdb_client_up->QueryGDBServer(remote_servers);
817   for (const auto &gdbserver : remote_servers) {
818     const char *socket_name_cstr =
819         gdbserver.second.empty() ? nullptr : gdbserver.second.c_str();
820     connection_urls.emplace_back(
821         MakeGdbServerUrl(m_platform_scheme, m_platform_hostname,
822                          gdbserver.first, socket_name_cstr));
823   }
824   return connection_urls.size();
825 }
826