1//===-- Socket.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 "lldb/Host/Socket.h"
10
11#include "lldb/Host/Config.h"
12#include "lldb/Host/Host.h"
13#include "lldb/Host/SocketAddress.h"
14#include "lldb/Host/common/TCPSocket.h"
15#include "lldb/Host/common/UDPSocket.h"
16#include "lldb/Utility/LLDBLog.h"
17#include "lldb/Utility/Log.h"
18
19#include "llvm/ADT/STLExtras.h"
20#include "llvm/ADT/StringExtras.h"
21#include "llvm/Support/Errno.h"
22#include "llvm/Support/Error.h"
23#include "llvm/Support/Regex.h"
24#include "llvm/Support/WindowsError.h"
25
26#if LLDB_ENABLE_POSIX
27#include "lldb/Host/posix/DomainSocket.h"
28
29#include <arpa/inet.h>
30#include <netdb.h>
31#include <netinet/in.h>
32#include <netinet/tcp.h>
33#include <sys/socket.h>
34#include <sys/un.h>
35#include <unistd.h>
36#endif
37
38#ifdef __linux__
39#include "lldb/Host/linux/AbstractSocket.h"
40#endif
41
42#ifdef __ANDROID__
43#include <arpa/inet.h>
44#include <asm-generic/errno-base.h>
45#include <cerrno>
46#include <fcntl.h>
47#include <linux/tcp.h>
48#include <sys/syscall.h>
49#include <unistd.h>
50#endif // __ANDROID__
51
52using namespace lldb;
53using namespace lldb_private;
54
55#if defined(_WIN32)
56typedef const char *set_socket_option_arg_type;
57typedef char *get_socket_option_arg_type;
58const NativeSocket Socket::kInvalidSocketValue = INVALID_SOCKET;
59#else  // #if defined(_WIN32)
60typedef const void *set_socket_option_arg_type;
61typedef void *get_socket_option_arg_type;
62const NativeSocket Socket::kInvalidSocketValue = -1;
63#endif // #if defined(_WIN32)
64
65static bool IsInterrupted() {
66#if defined(_WIN32)
67  return ::WSAGetLastError() == WSAEINTR;
68#else
69  return errno == EINTR;
70#endif
71}
72
73Socket::Socket(SocketProtocol protocol, bool should_close,
74               bool child_processes_inherit)
75    : IOObject(eFDTypeSocket), m_protocol(protocol),
76      m_socket(kInvalidSocketValue),
77      m_child_processes_inherit(child_processes_inherit),
78      m_should_close_fd(should_close) {}
79
80Socket::~Socket() { Close(); }
81
82llvm::Error Socket::Initialize() {
83#if defined(_WIN32)
84  auto wVersion = WINSOCK_VERSION;
85  WSADATA wsaData;
86  int err = ::WSAStartup(wVersion, &wsaData);
87  if (err == 0) {
88    if (wsaData.wVersion < wVersion) {
89      WSACleanup();
90      return llvm::make_error<llvm::StringError>(
91          "WSASock version is not expected.", llvm::inconvertibleErrorCode());
92    }
93  } else {
94    return llvm::errorCodeToError(llvm::mapWindowsError(::WSAGetLastError()));
95  }
96#endif
97
98  return llvm::Error::success();
99}
100
101void Socket::Terminate() {
102#if defined(_WIN32)
103  ::WSACleanup();
104#endif
105}
106
107std::unique_ptr<Socket> Socket::Create(const SocketProtocol protocol,
108                                       bool child_processes_inherit,
109                                       Status &error) {
110  error.Clear();
111
112  std::unique_ptr<Socket> socket_up;
113  switch (protocol) {
114  case ProtocolTcp:
115    socket_up =
116        std::make_unique<TCPSocket>(true, child_processes_inherit);
117    break;
118  case ProtocolUdp:
119    socket_up =
120        std::make_unique<UDPSocket>(true, child_processes_inherit);
121    break;
122  case ProtocolUnixDomain:
123#if LLDB_ENABLE_POSIX
124    socket_up =
125        std::make_unique<DomainSocket>(true, child_processes_inherit);
126#else
127    error.SetErrorString(
128        "Unix domain sockets are not supported on this platform.");
129#endif
130    break;
131  case ProtocolUnixAbstract:
132#ifdef __linux__
133    socket_up =
134        std::make_unique<AbstractSocket>(child_processes_inherit);
135#else
136    error.SetErrorString(
137        "Abstract domain sockets are not supported on this platform.");
138#endif
139    break;
140  }
141
142  if (error.Fail())
143    socket_up.reset();
144
145  return socket_up;
146}
147
148llvm::Expected<std::unique_ptr<Socket>>
149Socket::TcpConnect(llvm::StringRef host_and_port,
150                   bool child_processes_inherit) {
151  Log *log = GetLog(LLDBLog::Connection);
152  LLDB_LOG(log, "host_and_port = {0}", host_and_port);
153
154  Status error;
155  std::unique_ptr<Socket> connect_socket(
156      Create(ProtocolTcp, child_processes_inherit, error));
157  if (error.Fail())
158    return error.ToError();
159
160  error = connect_socket->Connect(host_and_port);
161  if (error.Success())
162    return std::move(connect_socket);
163
164  return error.ToError();
165}
166
167llvm::Expected<std::unique_ptr<TCPSocket>>
168Socket::TcpListen(llvm::StringRef host_and_port, bool child_processes_inherit,
169                  int backlog) {
170  Log *log = GetLog(LLDBLog::Connection);
171  LLDB_LOG(log, "host_and_port = {0}", host_and_port);
172
173  std::unique_ptr<TCPSocket> listen_socket(
174      new TCPSocket(true, child_processes_inherit));
175
176  Status error = listen_socket->Listen(host_and_port, backlog);
177  if (error.Fail())
178    return error.ToError();
179
180  return std::move(listen_socket);
181}
182
183llvm::Expected<std::unique_ptr<UDPSocket>>
184Socket::UdpConnect(llvm::StringRef host_and_port,
185                   bool child_processes_inherit) {
186  return UDPSocket::Connect(host_and_port, child_processes_inherit);
187}
188
189llvm::Expected<Socket::HostAndPort> Socket::DecodeHostAndPort(llvm::StringRef host_and_port) {
190  static llvm::Regex g_regex("([^:]+|\\[[0-9a-fA-F:]+.*\\]):([0-9]+)");
191  HostAndPort ret;
192  llvm::SmallVector<llvm::StringRef, 3> matches;
193  if (g_regex.match(host_and_port, &matches)) {
194    ret.hostname = matches[1].str();
195    // IPv6 addresses are wrapped in [] when specified with ports
196    if (ret.hostname.front() == '[' && ret.hostname.back() == ']')
197      ret.hostname = ret.hostname.substr(1, ret.hostname.size() - 2);
198    if (to_integer(matches[2], ret.port, 10))
199      return ret;
200  } else {
201    // If this was unsuccessful, then check if it's simply an unsigned 16-bit
202    // integer, representing a port with an empty host.
203    if (to_integer(host_and_port, ret.port, 10))
204      return ret;
205  }
206
207  return llvm::createStringError(llvm::inconvertibleErrorCode(),
208                                 "invalid host:port specification: '%s'",
209                                 host_and_port.str().c_str());
210}
211
212IOObject::WaitableHandle Socket::GetWaitableHandle() {
213  // TODO: On Windows, use WSAEventSelect
214  return m_socket;
215}
216
217Status Socket::Read(void *buf, size_t &num_bytes) {
218  Status error;
219  int bytes_received = 0;
220  do {
221    bytes_received = ::recv(m_socket, static_cast<char *>(buf), num_bytes, 0);
222  } while (bytes_received < 0 && IsInterrupted());
223
224  if (bytes_received < 0) {
225    SetLastError(error);
226    num_bytes = 0;
227  } else
228    num_bytes = bytes_received;
229
230  Log *log = GetLog(LLDBLog::Communication);
231  if (log) {
232    LLDB_LOGF(log,
233              "%p Socket::Read() (socket = %" PRIu64
234              ", src = %p, src_len = %" PRIu64 ", flags = 0) => %" PRIi64
235              " (error = %s)",
236              static_cast<void *>(this), static_cast<uint64_t>(m_socket), buf,
237              static_cast<uint64_t>(num_bytes),
238              static_cast<int64_t>(bytes_received), error.AsCString());
239  }
240
241  return error;
242}
243
244Status Socket::Write(const void *buf, size_t &num_bytes) {
245  const size_t src_len = num_bytes;
246  Status error;
247  int bytes_sent = 0;
248  do {
249    bytes_sent = Send(buf, num_bytes);
250  } while (bytes_sent < 0 && IsInterrupted());
251
252  if (bytes_sent < 0) {
253    SetLastError(error);
254    num_bytes = 0;
255  } else
256    num_bytes = bytes_sent;
257
258  Log *log = GetLog(LLDBLog::Communication);
259  if (log) {
260    LLDB_LOGF(log,
261              "%p Socket::Write() (socket = %" PRIu64
262              ", src = %p, src_len = %" PRIu64 ", flags = 0) => %" PRIi64
263              " (error = %s)",
264              static_cast<void *>(this), static_cast<uint64_t>(m_socket), buf,
265              static_cast<uint64_t>(src_len),
266              static_cast<int64_t>(bytes_sent), error.AsCString());
267  }
268
269  return error;
270}
271
272Status Socket::Close() {
273  Status error;
274  if (!IsValid() || !m_should_close_fd)
275    return error;
276
277  Log *log = GetLog(LLDBLog::Connection);
278  LLDB_LOGF(log, "%p Socket::Close (fd = %" PRIu64 ")",
279            static_cast<void *>(this), static_cast<uint64_t>(m_socket));
280
281#if defined(_WIN32)
282  bool success = closesocket(m_socket) == 0;
283#else
284  bool success = ::close(m_socket) == 0;
285#endif
286  // A reference to a FD was passed in, set it to an invalid value
287  m_socket = kInvalidSocketValue;
288  if (!success) {
289    SetLastError(error);
290  }
291
292  return error;
293}
294
295int Socket::GetOption(int level, int option_name, int &option_value) {
296  get_socket_option_arg_type option_value_p =
297      reinterpret_cast<get_socket_option_arg_type>(&option_value);
298  socklen_t option_value_size = sizeof(int);
299  return ::getsockopt(m_socket, level, option_name, option_value_p,
300                      &option_value_size);
301}
302
303int Socket::SetOption(int level, int option_name, int option_value) {
304  set_socket_option_arg_type option_value_p =
305      reinterpret_cast<get_socket_option_arg_type>(&option_value);
306  return ::setsockopt(m_socket, level, option_name, option_value_p,
307                      sizeof(option_value));
308}
309
310size_t Socket::Send(const void *buf, const size_t num_bytes) {
311  return ::send(m_socket, static_cast<const char *>(buf), num_bytes, 0);
312}
313
314void Socket::SetLastError(Status &error) {
315#if defined(_WIN32)
316  error.SetError(::WSAGetLastError(), lldb::eErrorTypeWin32);
317#else
318  error.SetErrorToErrno();
319#endif
320}
321
322NativeSocket Socket::CreateSocket(const int domain, const int type,
323                                  const int protocol,
324                                  bool child_processes_inherit, Status &error) {
325  error.Clear();
326  auto socket_type = type;
327#ifdef SOCK_CLOEXEC
328  if (!child_processes_inherit)
329    socket_type |= SOCK_CLOEXEC;
330#endif
331  auto sock = ::socket(domain, socket_type, protocol);
332  if (sock == kInvalidSocketValue)
333    SetLastError(error);
334
335  return sock;
336}
337
338NativeSocket Socket::AcceptSocket(NativeSocket sockfd, struct sockaddr *addr,
339                                  socklen_t *addrlen,
340                                  bool child_processes_inherit, Status &error) {
341  error.Clear();
342#if defined(ANDROID_USE_ACCEPT_WORKAROUND)
343  // Hack:
344  // This enables static linking lldb-server to an API 21 libc, but still
345  // having it run on older devices. It is necessary because API 21 libc's
346  // implementation of accept() uses the accept4 syscall(), which is not
347  // available in older kernels. Using an older libc would fix this issue, but
348  // introduce other ones, as the old libraries were quite buggy.
349  int fd = syscall(__NR_accept, sockfd, addr, addrlen);
350  if (fd >= 0 && !child_processes_inherit) {
351    int flags = ::fcntl(fd, F_GETFD);
352    if (flags != -1 && ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC) != -1)
353      return fd;
354    SetLastError(error);
355    close(fd);
356  }
357  return fd;
358#elif defined(SOCK_CLOEXEC) && defined(HAVE_ACCEPT4)
359  int flags = 0;
360  if (!child_processes_inherit) {
361    flags |= SOCK_CLOEXEC;
362  }
363  NativeSocket fd = llvm::sys::RetryAfterSignal(
364      static_cast<NativeSocket>(-1), ::accept4, sockfd, addr, addrlen, flags);
365#else
366  NativeSocket fd = llvm::sys::RetryAfterSignal(
367      static_cast<NativeSocket>(-1), ::accept, sockfd, addr, addrlen);
368#endif
369  if (fd == kInvalidSocketValue)
370    SetLastError(error);
371  return fd;
372}
373
374llvm::raw_ostream &lldb_private::operator<<(llvm::raw_ostream &OS,
375                                            const Socket::HostAndPort &HP) {
376  return OS << '[' << HP.hostname << ']' << ':' << HP.port;
377}
378