1 //===-- lldb-gdbserver.cpp --------------------------------------*- C++ -*-===// 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 <cerrno> 10 #include <cstdint> 11 #include <cstdio> 12 #include <cstdlib> 13 #include <cstring> 14 15 #ifndef _WIN32 16 #include <csignal> 17 #include <unistd.h> 18 #endif 19 20 #include "LLDBServerUtilities.h" 21 #include "Plugins/Process/gdb-remote/GDBRemoteCommunicationServerLLGS.h" 22 #include "Plugins/Process/gdb-remote/ProcessGDBRemoteLog.h" 23 #include "lldb/Host/Config.h" 24 #include "lldb/Host/ConnectionFileDescriptor.h" 25 #include "lldb/Host/FileSystem.h" 26 #include "lldb/Host/Pipe.h" 27 #include "lldb/Host/Socket.h" 28 #include "lldb/Host/common/NativeProcessProtocol.h" 29 #include "lldb/Target/Process.h" 30 #include "lldb/Utility/LLDBLog.h" 31 #include "lldb/Utility/Status.h" 32 #include "llvm/ADT/StringRef.h" 33 #include "llvm/Option/ArgList.h" 34 #include "llvm/Option/OptTable.h" 35 #include "llvm/Option/Option.h" 36 #include "llvm/Support/Errno.h" 37 #include "llvm/Support/WithColor.h" 38 39 #if defined(__linux__) 40 #include "Plugins/Process/Linux/NativeProcessLinux.h" 41 #elif defined(__FreeBSD__) 42 #include "Plugins/Process/FreeBSD/NativeProcessFreeBSD.h" 43 #elif defined(__NetBSD__) 44 #include "Plugins/Process/NetBSD/NativeProcessNetBSD.h" 45 #elif defined(_WIN32) 46 #include "Plugins/Process/Windows/Common/NativeProcessWindows.h" 47 #endif 48 49 #ifndef LLGS_PROGRAM_NAME 50 #define LLGS_PROGRAM_NAME "lldb-server" 51 #endif 52 53 #ifndef LLGS_VERSION_STR 54 #define LLGS_VERSION_STR "local_build" 55 #endif 56 57 using namespace llvm; 58 using namespace lldb; 59 using namespace lldb_private; 60 using namespace lldb_private::lldb_server; 61 using namespace lldb_private::process_gdb_remote; 62 63 namespace { 64 #if defined(__linux__) 65 typedef process_linux::NativeProcessLinux::Factory NativeProcessFactory; 66 #elif defined(__FreeBSD__) 67 typedef process_freebsd::NativeProcessFreeBSD::Factory NativeProcessFactory; 68 #elif defined(__NetBSD__) 69 typedef process_netbsd::NativeProcessNetBSD::Factory NativeProcessFactory; 70 #elif defined(_WIN32) 71 typedef NativeProcessWindows::Factory NativeProcessFactory; 72 #else 73 // Dummy implementation to make sure the code compiles 74 class NativeProcessFactory : public NativeProcessProtocol::Factory { 75 public: 76 llvm::Expected<std::unique_ptr<NativeProcessProtocol>> 77 Launch(ProcessLaunchInfo &launch_info, 78 NativeProcessProtocol::NativeDelegate &delegate, 79 MainLoop &mainloop) const override { 80 llvm_unreachable("Not implemented"); 81 } 82 llvm::Expected<std::unique_ptr<NativeProcessProtocol>> 83 Attach(lldb::pid_t pid, NativeProcessProtocol::NativeDelegate &delegate, 84 MainLoop &mainloop) const override { 85 llvm_unreachable("Not implemented"); 86 } 87 }; 88 #endif 89 } 90 91 #ifndef _WIN32 92 // Watch for signals 93 static int g_sighup_received_count = 0; 94 95 static void sighup_handler(MainLoopBase &mainloop) { 96 ++g_sighup_received_count; 97 98 Log *log = GetLog(LLDBLog::Process); 99 LLDB_LOGF(log, "lldb-server:%s swallowing SIGHUP (receive count=%d)", 100 __FUNCTION__, g_sighup_received_count); 101 102 if (g_sighup_received_count >= 2) 103 mainloop.RequestTermination(); 104 } 105 #endif // #ifndef _WIN32 106 107 void handle_attach_to_pid(GDBRemoteCommunicationServerLLGS &gdb_server, 108 lldb::pid_t pid) { 109 Status error = gdb_server.AttachToProcess(pid); 110 if (error.Fail()) { 111 fprintf(stderr, "error: failed to attach to pid %" PRIu64 ": %s\n", pid, 112 error.AsCString()); 113 exit(1); 114 } 115 } 116 117 void handle_attach_to_process_name(GDBRemoteCommunicationServerLLGS &gdb_server, 118 const std::string &process_name) { 119 // FIXME implement. 120 } 121 122 void handle_attach(GDBRemoteCommunicationServerLLGS &gdb_server, 123 const std::string &attach_target) { 124 assert(!attach_target.empty() && "attach_target cannot be empty"); 125 126 // First check if the attach_target is convertible to a long. If so, we'll use 127 // it as a pid. 128 char *end_p = nullptr; 129 const long int pid = strtol(attach_target.c_str(), &end_p, 10); 130 131 // We'll call it a match if the entire argument is consumed. 132 if (end_p && 133 static_cast<size_t>(end_p - attach_target.c_str()) == 134 attach_target.size()) 135 handle_attach_to_pid(gdb_server, static_cast<lldb::pid_t>(pid)); 136 else 137 handle_attach_to_process_name(gdb_server, attach_target); 138 } 139 140 void handle_launch(GDBRemoteCommunicationServerLLGS &gdb_server, 141 llvm::ArrayRef<llvm::StringRef> Arguments) { 142 ProcessLaunchInfo info; 143 info.GetFlags().Set(eLaunchFlagStopAtEntry | eLaunchFlagDebug | 144 eLaunchFlagDisableASLR); 145 info.SetArguments(Args(Arguments), true); 146 147 llvm::SmallString<64> cwd; 148 if (std::error_code ec = llvm::sys::fs::current_path(cwd)) { 149 llvm::errs() << "Error getting current directory: " << ec.message() << "\n"; 150 exit(1); 151 } 152 FileSpec cwd_spec(cwd); 153 FileSystem::Instance().Resolve(cwd_spec); 154 info.SetWorkingDirectory(cwd_spec); 155 info.GetEnvironment() = Host::GetEnvironment(); 156 157 gdb_server.SetLaunchInfo(info); 158 159 Status error = gdb_server.LaunchProcess(); 160 if (error.Fail()) { 161 llvm::errs() << llvm::formatv("error: failed to launch '{0}': {1}\n", 162 Arguments[0], error); 163 exit(1); 164 } 165 } 166 167 Status writeSocketIdToPipe(Pipe &port_pipe, llvm::StringRef socket_id) { 168 size_t bytes_written = 0; 169 // Write the port number as a C string with the NULL terminator. 170 return port_pipe.Write(socket_id.data(), socket_id.size() + 1, bytes_written); 171 } 172 173 Status writeSocketIdToPipe(const char *const named_pipe_path, 174 llvm::StringRef socket_id) { 175 Pipe port_name_pipe; 176 // Wait for 10 seconds for pipe to be opened. 177 auto error = port_name_pipe.OpenAsWriterWithTimeout(named_pipe_path, false, 178 std::chrono::seconds{10}); 179 if (error.Fail()) 180 return error; 181 return writeSocketIdToPipe(port_name_pipe, socket_id); 182 } 183 184 Status writeSocketIdToPipe(lldb::pipe_t unnamed_pipe, 185 llvm::StringRef socket_id) { 186 Pipe port_pipe{LLDB_INVALID_PIPE, unnamed_pipe}; 187 return writeSocketIdToPipe(port_pipe, socket_id); 188 } 189 190 void ConnectToRemote(MainLoop &mainloop, 191 GDBRemoteCommunicationServerLLGS &gdb_server, 192 bool reverse_connect, llvm::StringRef host_and_port, 193 const char *const progname, const char *const subcommand, 194 const char *const named_pipe_path, pipe_t unnamed_pipe, 195 int connection_fd) { 196 Status error; 197 198 std::unique_ptr<Connection> connection_up; 199 std::string url; 200 201 if (connection_fd != -1) { 202 url = llvm::formatv("fd://{0}", connection_fd).str(); 203 204 // Create the connection. 205 #if LLDB_ENABLE_POSIX && !defined _WIN32 206 ::fcntl(connection_fd, F_SETFD, FD_CLOEXEC); 207 #endif 208 } else if (!host_and_port.empty()) { 209 llvm::Expected<std::string> url_exp = 210 LLGSArgToURL(host_and_port, reverse_connect); 211 if (!url_exp) { 212 llvm::errs() << llvm::formatv("error: invalid host:port or URL '{0}': " 213 "{1}\n", 214 host_and_port, 215 llvm::toString(url_exp.takeError())); 216 exit(-1); 217 } 218 219 url = std::move(url_exp.get()); 220 } 221 222 if (!url.empty()) { 223 // Create the connection or server. 224 std::unique_ptr<ConnectionFileDescriptor> conn_fd_up{ 225 new ConnectionFileDescriptor}; 226 auto connection_result = conn_fd_up->Connect( 227 url, 228 [named_pipe_path, unnamed_pipe](llvm::StringRef socket_id) { 229 // If we have a named pipe to write the socket id back to, do that 230 // now. 231 if (named_pipe_path && named_pipe_path[0]) { 232 Status error = writeSocketIdToPipe(named_pipe_path, socket_id); 233 if (error.Fail()) 234 llvm::errs() << llvm::formatv( 235 "failed to write to the named peipe '{0}': {1}\n", 236 named_pipe_path, error.AsCString()); 237 } 238 // If we have an unnamed pipe to write the socket id back to, do 239 // that now. 240 else if (unnamed_pipe != LLDB_INVALID_PIPE) { 241 Status error = writeSocketIdToPipe(unnamed_pipe, socket_id); 242 if (error.Fail()) 243 llvm::errs() << llvm::formatv( 244 "failed to write to the unnamed pipe: {0}\n", error); 245 } 246 }, 247 &error); 248 249 if (error.Fail()) { 250 llvm::errs() << llvm::formatv( 251 "error: failed to connect to client at '{0}': {1}\n", url, error); 252 exit(-1); 253 } 254 if (connection_result != eConnectionStatusSuccess) { 255 llvm::errs() << llvm::formatv( 256 "error: failed to connect to client at '{0}' " 257 "(connection status: {1})\n", 258 url, static_cast<int>(connection_result)); 259 exit(-1); 260 } 261 connection_up = std::move(conn_fd_up); 262 } 263 error = gdb_server.InitializeConnection(std::move(connection_up)); 264 if (error.Fail()) { 265 llvm::errs() << llvm::formatv("failed to initialize connection\n", error); 266 exit(-1); 267 } 268 llvm::outs() << "Connection established.\n"; 269 } 270 271 namespace { 272 enum ID { 273 OPT_INVALID = 0, // This is not an option ID. 274 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \ 275 HELPTEXT, METAVAR, VALUES) \ 276 OPT_##ID, 277 #include "LLGSOptions.inc" 278 #undef OPTION 279 }; 280 281 #define PREFIX(NAME, VALUE) \ 282 constexpr llvm::StringLiteral NAME##_init[] = VALUE; \ 283 constexpr llvm::ArrayRef<llvm::StringLiteral> NAME( \ 284 NAME##_init, std::size(NAME##_init) - 1); 285 #include "LLGSOptions.inc" 286 #undef PREFIX 287 288 static constexpr opt::OptTable::Info InfoTable[] = { 289 #define OPTION(PREFIX, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM, \ 290 HELPTEXT, METAVAR, VALUES) \ 291 { \ 292 PREFIX, NAME, HELPTEXT, \ 293 METAVAR, OPT_##ID, opt::Option::KIND##Class, \ 294 PARAM, FLAGS, OPT_##GROUP, \ 295 OPT_##ALIAS, ALIASARGS, VALUES}, 296 #include "LLGSOptions.inc" 297 #undef OPTION 298 }; 299 300 class LLGSOptTable : public opt::GenericOptTable { 301 public: 302 LLGSOptTable() : opt::GenericOptTable(InfoTable) {} 303 304 void PrintHelp(llvm::StringRef Name) { 305 std::string Usage = 306 (Name + " [options] [[host]:port] [[--] program args...]").str(); 307 OptTable::printHelp(llvm::outs(), Usage.c_str(), "lldb-server"); 308 llvm::outs() << R"( 309 DESCRIPTION 310 lldb-server connects to the LLDB client, which drives the debugging session. 311 If no connection options are given, the [host]:port argument must be present 312 and will denote the address that lldb-server will listen on. [host] defaults 313 to "localhost" if empty. Port can be zero, in which case the port number will 314 be chosen dynamically and written to destinations given by --named-pipe and 315 --pipe arguments. 316 317 If no target is selected at startup, lldb-server can be directed by the LLDB 318 client to launch or attach to a process. 319 320 )"; 321 } 322 }; 323 } // namespace 324 325 int main_gdbserver(int argc, char *argv[]) { 326 Status error; 327 MainLoop mainloop; 328 #ifndef _WIN32 329 // Setup signal handlers first thing. 330 signal(SIGPIPE, SIG_IGN); 331 MainLoop::SignalHandleUP sighup_handle = 332 mainloop.RegisterSignal(SIGHUP, sighup_handler, error); 333 #endif 334 335 const char *progname = argv[0]; 336 const char *subcommand = argv[1]; 337 std::string attach_target; 338 std::string named_pipe_path; 339 std::string log_file; 340 StringRef 341 log_channels; // e.g. "lldb process threads:gdb-remote default:linux all" 342 lldb::pipe_t unnamed_pipe = LLDB_INVALID_PIPE; 343 bool reverse_connect = false; 344 int connection_fd = -1; 345 346 // ProcessLaunchInfo launch_info; 347 ProcessAttachInfo attach_info; 348 349 LLGSOptTable Opts; 350 llvm::BumpPtrAllocator Alloc; 351 llvm::StringSaver Saver(Alloc); 352 bool HasError = false; 353 opt::InputArgList Args = Opts.parseArgs(argc - 1, argv + 1, OPT_UNKNOWN, 354 Saver, [&](llvm::StringRef Msg) { 355 WithColor::error() << Msg << "\n"; 356 HasError = true; 357 }); 358 std::string Name = 359 (llvm::sys::path::filename(argv[0]) + " g[dbserver]").str(); 360 std::string HelpText = 361 "Use '" + Name + " --help' for a complete list of options.\n"; 362 if (HasError) { 363 llvm::errs() << HelpText; 364 return 1; 365 } 366 367 if (Args.hasArg(OPT_help)) { 368 Opts.PrintHelp(Name); 369 return 0; 370 } 371 372 #ifndef _WIN32 373 if (Args.hasArg(OPT_setsid)) { 374 // Put llgs into a new session. Terminals group processes 375 // into sessions and when a special terminal key sequences 376 // (like control+c) are typed they can cause signals to go out to 377 // all processes in a session. Using this --setsid (-S) option 378 // will cause debugserver to run in its own sessions and be free 379 // from such issues. 380 // 381 // This is useful when llgs is spawned from a command 382 // line application that uses llgs to do the debugging, 383 // yet that application doesn't want llgs receiving the 384 // signals sent to the session (i.e. dying when anyone hits ^C). 385 { 386 const ::pid_t new_sid = setsid(); 387 if (new_sid == -1) { 388 WithColor::warning() 389 << llvm::formatv("failed to set new session id for {0} ({1})\n", 390 LLGS_PROGRAM_NAME, llvm::sys::StrError()); 391 } 392 } 393 } 394 #endif 395 396 log_file = Args.getLastArgValue(OPT_log_file).str(); 397 log_channels = Args.getLastArgValue(OPT_log_channels); 398 named_pipe_path = Args.getLastArgValue(OPT_named_pipe).str(); 399 reverse_connect = Args.hasArg(OPT_reverse_connect); 400 attach_target = Args.getLastArgValue(OPT_attach).str(); 401 if (Args.hasArg(OPT_pipe)) { 402 uint64_t Arg; 403 if (!llvm::to_integer(Args.getLastArgValue(OPT_pipe), Arg)) { 404 WithColor::error() << "invalid '--pipe' argument\n" << HelpText; 405 return 1; 406 } 407 unnamed_pipe = (pipe_t)Arg; 408 } 409 if (Args.hasArg(OPT_fd)) { 410 if (!llvm::to_integer(Args.getLastArgValue(OPT_fd), connection_fd)) { 411 WithColor::error() << "invalid '--fd' argument\n" << HelpText; 412 return 1; 413 } 414 } 415 416 if (!LLDBServerUtilities::SetupLogging( 417 log_file, log_channels, 418 LLDB_LOG_OPTION_PREPEND_TIMESTAMP | 419 LLDB_LOG_OPTION_PREPEND_FILE_FUNCTION)) 420 return -1; 421 422 std::vector<llvm::StringRef> Inputs; 423 for (opt::Arg *Arg : Args.filtered(OPT_INPUT)) 424 Inputs.push_back(Arg->getValue()); 425 if (opt::Arg *Arg = Args.getLastArg(OPT_REM)) { 426 for (const char *Val : Arg->getValues()) 427 Inputs.push_back(Val); 428 } 429 if (Inputs.empty() && connection_fd == -1) { 430 WithColor::error() << "no connection arguments\n" << HelpText; 431 return 1; 432 } 433 434 NativeProcessFactory factory; 435 GDBRemoteCommunicationServerLLGS gdb_server(mainloop, factory); 436 437 llvm::StringRef host_and_port; 438 if (!Inputs.empty()) { 439 host_and_port = Inputs.front(); 440 Inputs.erase(Inputs.begin()); 441 } 442 443 // Any arguments left over are for the program that we need to launch. If 444 // there 445 // are no arguments, then the GDB server will start up and wait for an 'A' 446 // packet 447 // to launch a program, or a vAttach packet to attach to an existing process, 448 // unless 449 // explicitly asked to attach with the --attach={pid|program_name} form. 450 if (!attach_target.empty()) 451 handle_attach(gdb_server, attach_target); 452 else if (!Inputs.empty()) 453 handle_launch(gdb_server, Inputs); 454 455 // Print version info. 456 printf("%s-%s\n", LLGS_PROGRAM_NAME, LLGS_VERSION_STR); 457 458 ConnectToRemote(mainloop, gdb_server, reverse_connect, host_and_port, 459 progname, subcommand, named_pipe_path.c_str(), 460 unnamed_pipe, connection_fd); 461 462 if (!gdb_server.IsConnected()) { 463 fprintf(stderr, "no connection information provided, unable to run\n"); 464 return 1; 465 } 466 467 Status ret = mainloop.Run(); 468 if (ret.Fail()) { 469 fprintf(stderr, "lldb-server terminating due to error: %s\n", 470 ret.AsCString()); 471 return 1; 472 } 473 fprintf(stderr, "lldb-server exiting...\n"); 474 475 return 0; 476 } 477