1//===-- GDBRemoteCommunicationServer.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 <cerrno>
10
11#include "lldb/Host/Config.h"
12
13#include "GDBRemoteCommunicationServer.h"
14
15#include "ProcessGDBRemoteLog.h"
16#include "lldb/Utility/StreamString.h"
17#include "lldb/Utility/StringExtractorGDBRemote.h"
18#include "lldb/Utility/UnimplementedError.h"
19#include "llvm/Support/JSON.h"
20#include <cstring>
21
22using namespace lldb;
23using namespace lldb_private;
24using namespace lldb_private::process_gdb_remote;
25using namespace llvm;
26
27GDBRemoteCommunicationServer::GDBRemoteCommunicationServer()
28    : GDBRemoteCommunication(), m_exit_now(false) {
29  RegisterPacketHandler(
30      StringExtractorGDBRemote::eServerPacketType_QEnableErrorStrings,
31      [this](StringExtractorGDBRemote packet, Status &error, bool &interrupt,
32             bool &quit) { return this->Handle_QErrorStringEnable(packet); });
33}
34
35GDBRemoteCommunicationServer::~GDBRemoteCommunicationServer() = default;
36
37void GDBRemoteCommunicationServer::RegisterPacketHandler(
38    StringExtractorGDBRemote::ServerPacketType packet_type,
39    PacketHandler handler) {
40  m_packet_handlers[packet_type] = std::move(handler);
41}
42
43GDBRemoteCommunication::PacketResult
44GDBRemoteCommunicationServer::GetPacketAndSendResponse(
45    Timeout<std::micro> timeout, Status &error, bool &interrupt, bool &quit) {
46  StringExtractorGDBRemote packet;
47
48  PacketResult packet_result = ReadPacket(packet, timeout, false);
49  if (packet_result == PacketResult::Success) {
50    const StringExtractorGDBRemote::ServerPacketType packet_type =
51        packet.GetServerPacketType();
52    switch (packet_type) {
53    case StringExtractorGDBRemote::eServerPacketType_nack:
54    case StringExtractorGDBRemote::eServerPacketType_ack:
55      break;
56
57    case StringExtractorGDBRemote::eServerPacketType_invalid:
58      error.SetErrorString("invalid packet");
59      quit = true;
60      break;
61
62    case StringExtractorGDBRemote::eServerPacketType_unimplemented:
63      packet_result = SendUnimplementedResponse(packet.GetStringRef().data());
64      break;
65
66    default:
67      auto handler_it = m_packet_handlers.find(packet_type);
68      if (handler_it == m_packet_handlers.end())
69        packet_result = SendUnimplementedResponse(packet.GetStringRef().data());
70      else
71        packet_result = handler_it->second(packet, error, interrupt, quit);
72      break;
73    }
74  } else {
75    if (!IsConnected()) {
76      error.SetErrorString("lost connection");
77      quit = true;
78    } else {
79      error.SetErrorString("timeout");
80    }
81  }
82
83  // Check if anything occurred that would force us to want to exit.
84  if (m_exit_now)
85    quit = true;
86
87  return packet_result;
88}
89
90GDBRemoteCommunication::PacketResult
91GDBRemoteCommunicationServer::SendUnimplementedResponse(const char *) {
92  // TODO: Log the packet we aren't handling...
93  return SendPacketNoLock("");
94}
95
96GDBRemoteCommunication::PacketResult
97GDBRemoteCommunicationServer::SendErrorResponse(uint8_t err) {
98  char packet[16];
99  int packet_len = ::snprintf(packet, sizeof(packet), "E%2.2x", err);
100  assert(packet_len < (int)sizeof(packet));
101  return SendPacketNoLock(llvm::StringRef(packet, packet_len));
102}
103
104GDBRemoteCommunication::PacketResult
105GDBRemoteCommunicationServer::SendErrorResponse(const Status &error) {
106  if (m_send_error_strings) {
107    lldb_private::StreamString packet;
108    packet.Printf("E%2.2x;", static_cast<uint8_t>(error.GetError()));
109    packet.PutStringAsRawHex8(error.AsCString());
110    return SendPacketNoLock(packet.GetString());
111  } else
112    return SendErrorResponse(error.GetError());
113}
114
115GDBRemoteCommunication::PacketResult
116GDBRemoteCommunicationServer::SendErrorResponse(llvm::Error error) {
117  assert(error);
118  std::unique_ptr<llvm::ErrorInfoBase> EIB;
119  std::unique_ptr<UnimplementedError> UE;
120  llvm::handleAllErrors(
121      std::move(error),
122      [&](std::unique_ptr<UnimplementedError> E) { UE = std::move(E); },
123      [&](std::unique_ptr<llvm::ErrorInfoBase> E) { EIB = std::move(E); });
124
125  if (EIB)
126    return SendErrorResponse(Status(llvm::Error(std::move(EIB))));
127  return SendUnimplementedResponse("");
128}
129
130GDBRemoteCommunication::PacketResult
131GDBRemoteCommunicationServer::Handle_QErrorStringEnable(
132    StringExtractorGDBRemote &packet) {
133  m_send_error_strings = true;
134  return SendOKResponse();
135}
136
137GDBRemoteCommunication::PacketResult
138GDBRemoteCommunicationServer::SendIllFormedResponse(
139    const StringExtractorGDBRemote &failed_packet, const char *message) {
140  Log *log = GetLog(GDBRLog::Packets);
141  LLDB_LOGF(log, "GDBRemoteCommunicationServer::%s: ILLFORMED: '%s' (%s)",
142            __FUNCTION__, failed_packet.GetStringRef().data(),
143            message ? message : "");
144  return SendErrorResponse(0x03);
145}
146
147GDBRemoteCommunication::PacketResult
148GDBRemoteCommunicationServer::SendOKResponse() {
149  return SendPacketNoLock("OK");
150}
151
152GDBRemoteCommunication::PacketResult
153GDBRemoteCommunicationServer::SendJSONResponse(const json::Value &value) {
154  std::string json_string;
155  raw_string_ostream os(json_string);
156  os << value;
157  os.flush();
158  StreamGDBRemote escaped_response;
159  escaped_response.PutEscapedBytes(json_string.c_str(), json_string.size());
160  return SendPacketNoLock(escaped_response.GetString());
161}
162
163GDBRemoteCommunication::PacketResult
164GDBRemoteCommunicationServer::SendJSONResponse(Expected<json::Value> value) {
165  if (!value)
166    return SendErrorResponse(value.takeError());
167  return SendJSONResponse(*value);
168}
169