1 //===-- GDBRemoteCommunication.h --------------------------------*- 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 #ifndef LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATION_H 10 #define LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATION_H 11 12 #include "GDBRemoteCommunicationHistory.h" 13 14 #include <condition_variable> 15 #include <future> 16 #include <mutex> 17 #include <queue> 18 #include <string> 19 #include <vector> 20 21 #include "lldb/Core/Communication.h" 22 #include "lldb/Host/Config.h" 23 #include "lldb/Host/HostThread.h" 24 #include "lldb/Utility/Args.h" 25 #include "lldb/Utility/Listener.h" 26 #include "lldb/Utility/Predicate.h" 27 #include "lldb/Utility/StringExtractorGDBRemote.h" 28 #include "lldb/lldb-public.h" 29 30 namespace lldb_private { 31 namespace repro { 32 class PacketRecorder; 33 } 34 namespace process_gdb_remote { 35 36 enum GDBStoppointType { 37 eStoppointInvalid = -1, 38 eBreakpointSoftware = 0, 39 eBreakpointHardware, 40 eWatchpointWrite, 41 eWatchpointRead, 42 eWatchpointReadWrite 43 }; 44 45 enum class CompressionType { 46 None = 0, // no compression 47 ZlibDeflate, // zlib's deflate compression scheme, requires zlib or Apple's 48 // libcompression 49 LZFSE, // an Apple compression scheme, requires Apple's libcompression 50 LZ4, // lz compression - called "lz4 raw" in libcompression terms, compat with 51 // https://code.google.com/p/lz4/ 52 LZMA, // Lempel–Ziv–Markov chain algorithm 53 }; 54 55 // Data included in the vFile:fstat packet. 56 // https://sourceware.org/gdb/onlinedocs/gdb/struct-stat.html#struct-stat 57 struct GDBRemoteFStatData { 58 llvm::support::ubig32_t gdb_st_dev; 59 llvm::support::ubig32_t gdb_st_ino; 60 llvm::support::ubig32_t gdb_st_mode; 61 llvm::support::ubig32_t gdb_st_nlink; 62 llvm::support::ubig32_t gdb_st_uid; 63 llvm::support::ubig32_t gdb_st_gid; 64 llvm::support::ubig32_t gdb_st_rdev; 65 llvm::support::ubig64_t gdb_st_size; 66 llvm::support::ubig64_t gdb_st_blksize; 67 llvm::support::ubig64_t gdb_st_blocks; 68 llvm::support::ubig32_t gdb_st_atime; 69 llvm::support::ubig32_t gdb_st_mtime; 70 llvm::support::ubig32_t gdb_st_ctime; 71 }; 72 static_assert(sizeof(GDBRemoteFStatData) == 64, 73 "size of GDBRemoteFStatData is not 64"); 74 75 enum GDBErrno { 76 #define HANDLE_ERRNO(name, value) GDB_##name = value, 77 #include "Plugins/Process/gdb-remote/GDBRemoteErrno.def" 78 GDB_EUNKNOWN = 9999 79 }; 80 81 class ProcessGDBRemote; 82 83 class GDBRemoteCommunication : public Communication { 84 public: 85 enum class PacketType { Invalid = 0, Standard, Notify }; 86 87 enum class PacketResult { 88 Success = 0, // Success 89 ErrorSendFailed, // Status sending the packet 90 ErrorSendAck, // Didn't get an ack back after sending a packet 91 ErrorReplyFailed, // Status getting the reply 92 ErrorReplyTimeout, // Timed out waiting for reply 93 ErrorReplyInvalid, // Got a reply but it wasn't valid for the packet that 94 // was sent 95 ErrorReplyAck, // Sending reply ack failed 96 ErrorDisconnected, // We were disconnected 97 ErrorNoSequenceLock // We couldn't get the sequence lock for a multi-packet 98 // request 99 }; 100 101 // Class to change the timeout for a given scope and restore it to the 102 // original value when the 103 // created ScopedTimeout object got out of scope 104 class ScopedTimeout { 105 public: 106 ScopedTimeout(GDBRemoteCommunication &gdb_comm, 107 std::chrono::seconds timeout); 108 ~ScopedTimeout(); 109 110 private: 111 GDBRemoteCommunication &m_gdb_comm; 112 std::chrono::seconds m_saved_timeout; 113 // Don't ever reduce the timeout for a packet, only increase it. If the 114 // requested timeout if less than the current timeout, we don't set it 115 // and won't need to restore it. 116 bool m_timeout_modified; 117 }; 118 119 GDBRemoteCommunication(); 120 121 ~GDBRemoteCommunication() override; 122 123 PacketResult GetAck(); 124 125 size_t SendAck(); 126 127 size_t SendNack(); 128 129 char CalculcateChecksum(llvm::StringRef payload); 130 131 PacketType CheckForPacket(const uint8_t *src, size_t src_len, 132 StringExtractorGDBRemote &packet); 133 GetSendAcks()134 bool GetSendAcks() { return m_send_acks; } 135 136 // Set the global packet timeout. 137 // 138 // For clients, this is the timeout that gets used when sending 139 // packets and waiting for responses. For servers, this is used when waiting 140 // for ACKs. SetPacketTimeout(std::chrono::seconds packet_timeout)141 std::chrono::seconds SetPacketTimeout(std::chrono::seconds packet_timeout) { 142 const auto old_packet_timeout = m_packet_timeout; 143 m_packet_timeout = packet_timeout; 144 return old_packet_timeout; 145 } 146 GetPacketTimeout()147 std::chrono::seconds GetPacketTimeout() const { return m_packet_timeout; } 148 149 // Start a debugserver instance on the current host using the 150 // supplied connection URL. 151 Status StartDebugserverProcess( 152 const char *url, 153 Platform *platform, // If non nullptr, then check with the platform for 154 // the GDB server binary if it can't be located 155 ProcessLaunchInfo &launch_info, uint16_t *port, const Args *inferior_args, 156 int pass_comm_fd); // Communication file descriptor to pass during 157 // fork/exec to avoid having to connect/accept 158 159 void DumpHistory(Stream &strm); 160 161 void SetPacketRecorder(repro::PacketRecorder *recorder); 162 163 static llvm::Error ConnectLocally(GDBRemoteCommunication &client, 164 GDBRemoteCommunication &server); 165 166 /// Expand GDB run-length encoding. 167 static std::string ExpandRLE(std::string); 168 169 protected: 170 std::chrono::seconds m_packet_timeout; 171 uint32_t m_echo_number; 172 LazyBool m_supports_qEcho; 173 GDBRemoteCommunicationHistory m_history; 174 bool m_send_acks; 175 bool m_is_platform; // Set to true if this class represents a platform, 176 // false if this class represents a debug session for 177 // a single process 178 179 std::string m_bytes; 180 std::recursive_mutex m_bytes_mutex; 181 CompressionType m_compression_type; 182 183 PacketResult SendPacketNoLock(llvm::StringRef payload); 184 PacketResult SendNotificationPacketNoLock(llvm::StringRef notify_type, 185 std::deque<std::string>& queue, 186 llvm::StringRef payload); 187 PacketResult SendRawPacketNoLock(llvm::StringRef payload, 188 bool skip_ack = false); 189 190 PacketResult ReadPacket(StringExtractorGDBRemote &response, 191 Timeout<std::micro> timeout, bool sync_on_timeout); 192 193 PacketResult WaitForPacketNoLock(StringExtractorGDBRemote &response, 194 Timeout<std::micro> timeout, 195 bool sync_on_timeout); 196 CompressionIsEnabled()197 bool CompressionIsEnabled() { 198 return m_compression_type != CompressionType::None; 199 } 200 201 // If compression is enabled, decompress the packet in m_bytes and update 202 // m_bytes with the uncompressed version. 203 // Returns 'true' packet was decompressed and m_bytes is the now-decompressed 204 // text. 205 // Returns 'false' if unable to decompress or if the checksum was invalid. 206 // 207 // NB: Once the packet has been decompressed, checksum cannot be computed 208 // based 209 // on m_bytes. The checksum was for the compressed packet. 210 bool DecompressPacket(); 211 212 Status StartListenThread(const char *hostname = "127.0.0.1", 213 uint16_t port = 0); 214 215 bool JoinListenThread(); 216 217 lldb::thread_result_t ListenThread(); 218 219 private: 220 // Promise used to grab the port number from listening thread 221 std::promise<uint16_t> m_port_promise; 222 223 HostThread m_listen_thread; 224 std::string m_listen_url; 225 226 #if defined(HAVE_LIBCOMPRESSION) 227 CompressionType m_decompression_scratch_type = CompressionType::None; 228 void *m_decompression_scratch = nullptr; 229 #endif 230 231 GDBRemoteCommunication(const GDBRemoteCommunication &) = delete; 232 const GDBRemoteCommunication & 233 operator=(const GDBRemoteCommunication &) = delete; 234 }; 235 236 } // namespace process_gdb_remote 237 } // namespace lldb_private 238 239 namespace llvm { 240 template <> 241 struct format_provider< 242 lldb_private::process_gdb_remote::GDBRemoteCommunication::PacketResult> { 243 static void format(const lldb_private::process_gdb_remote:: 244 GDBRemoteCommunication::PacketResult &state, 245 raw_ostream &Stream, StringRef Style); 246 }; 247 } // namespace llvm 248 249 #endif // LLDB_SOURCE_PLUGINS_PROCESS_GDB_REMOTE_GDBREMOTECOMMUNICATION_H 250