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