//===-- Socket.cpp --------------------------------------------------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

#include "lldb/Host/Socket.h"

#include "lldb/Host/Config.h"

#include "lldb/Host/Host.h"

#include "lldb/Host/SocketAddress.h"

#include "lldb/Host/common/TCPSocket.h"

#include "lldb/Host/common/UDPSocket.h"

#include "lldb/Utility/LLDBLog.h"

#include "lldb/Utility/Log.h"

#include "llvm/ADT/STLExtras.h"

#include "llvm/ADT/StringExtras.h"

#include "llvm/Support/Errno.h"

#include "llvm/Support/Error.h"

#include "llvm/Support/Regex.h"

#include "llvm/Support/WindowsError.h"

#if LLDB_ENABLE_POSIX

#include "lldb/Host/posix/DomainSocket.h"

#include <arpa/inet.h>

#include <netdb.h>

#include <netinet/in.h>

#include <netinet/tcp.h>

#include <sys/socket.h>

#include <sys/un.h>

#include <unistd.h>

#endif

#ifdef __linux__

#include "lldb/Host/linux/AbstractSocket.h"

#endif

#ifdef __ANDROID__

#include <arpa/inet.h>

#include <asm-generic/errno-base.h>

#include <cerrno>

#include <fcntl.h>

#include <linux/tcp.h>

#include <sys/syscall.h>

#include <unistd.h>

#endif // __ANDROID__

using namespace lldb;

using namespace lldb_private;

#if defined(_WIN32)

typedef const char *set_socket_option_arg_type;

typedef char *get_socket_option_arg_type;

const NativeSocket Socket::kInvalidSocketValue = INVALID_SOCKET;

#else  // #if defined(_WIN32)

typedef const void *set_socket_option_arg_type;

typedef void *get_socket_option_arg_type;

const NativeSocket Socket::kInvalidSocketValue = -1;

#endif // #if defined(_WIN32)

static bool IsInterrupted() {

#if defined(_WIN32)

  return ::WSAGetLastError() == WSAEINTR;

#else

  return errno == EINTR;

#endif

}

Socket::Socket(SocketProtocol protocol, bool should_close,

               bool child_processes_inherit)

    : IOObject(eFDTypeSocket), m_protocol(protocol),

      m_socket(kInvalidSocketValue),

      m_child_processes_inherit(child_processes_inherit),

      m_should_close_fd(should_close) {}

Socket::~Socket() { Close(); }

llvm::Error Socket::Initialize() {

#if defined(_WIN32)

  auto wVersion = WINSOCK_VERSION;

  WSADATA wsaData;

  int err = ::WSAStartup(wVersion, &wsaData);

  if (err == 0) {

    if (wsaData.wVersion < wVersion) {

      WSACleanup();

      return llvm::make_error<llvm::StringError>(

          "WSASock version is not expected.", llvm::inconvertibleErrorCode());

    }

  } else {

    return llvm::errorCodeToError(llvm::mapWindowsError(::WSAGetLastError()));

  }

#endif

  return llvm::Error::success();

}

void Socket::Terminate() {

#if defined(_WIN32)

  ::WSACleanup();

#endif

}

std::unique_ptr<Socket> Socket::Create(const SocketProtocol protocol,

                                       bool child_processes_inherit,

                                       Status &error) {

  error.Clear();

  std::unique_ptr<Socket> socket_up;

  switch (protocol) {

  case ProtocolTcp:

    socket_up =

        std::make_unique<TCPSocket>(true, child_processes_inherit);

    break;

  case ProtocolUdp:

    socket_up =

        std::make_unique<UDPSocket>(true, child_processes_inherit);

    break;

  case ProtocolUnixDomain:

#if LLDB_ENABLE_POSIX

    socket_up =

        std::make_unique<DomainSocket>(true, child_processes_inherit);

#else

    error.SetErrorString(

        "Unix domain sockets are not supported on this platform.");

#endif

    break;

  case ProtocolUnixAbstract:

#ifdef __linux__

    socket_up =

        std::make_unique<AbstractSocket>(child_processes_inherit);

#else

    error.SetErrorString(

        "Abstract domain sockets are not supported on this platform.");

#endif

    break;

  }

  if (error.Fail())

    socket_up.reset();

  return socket_up;

}

llvm::Expected<std::unique_ptr<Socket>>

Socket::TcpConnect(llvm::StringRef host_and_port,

                   bool child_processes_inherit) {

  Log *log = GetLog(LLDBLog::Connection);

  LLDB_LOG(log, "host_and_port = {0}", host_and_port);

  Status error;

  std::unique_ptr<Socket> connect_socket(

      Create(ProtocolTcp, child_processes_inherit, error));

  if (error.Fail())

    return error.ToError();

  error = connect_socket->Connect(host_and_port);

  if (error.Success())

    return std::move(connect_socket);

  return error.ToError();

}

llvm::Expected<std::unique_ptr<TCPSocket>>

Socket::TcpListen(llvm::StringRef host_and_port, bool child_processes_inherit,

                  int backlog) {

  Log *log = GetLog(LLDBLog::Connection);

  LLDB_LOG(log, "host_and_port = {0}", host_and_port);

  std::unique_ptr<TCPSocket> listen_socket(

      new TCPSocket(true, child_processes_inherit));

  Status error = listen_socket->Listen(host_and_port, backlog);

  if (error.Fail())

    return error.ToError();

  return std::move(listen_socket);

}

llvm::Expected<std::unique_ptr<UDPSocket>>

Socket::UdpConnect(llvm::StringRef host_and_port,

                   bool child_processes_inherit) {

  return UDPSocket::Connect(host_and_port, child_processes_inherit);

}

llvm::Expected<Socket::HostAndPort> Socket::DecodeHostAndPort(llvm::StringRef host_and_port) {

  static llvm::Regex g_regex("([^:]+|\\[[0-9a-fA-F:]+.*\\]):([0-9]+)");

  HostAndPort ret;

  llvm::SmallVector<llvm::StringRef, 3> matches;

  if (g_regex.match(host_and_port, &matches)) {

    ret.hostname = matches[1].str();

    // IPv6 addresses are wrapped in [] when specified with ports

    if (ret.hostname.front() == '[' && 
ret.hostname.back() == ']'161
)

      ret.hostname = ret.hostname.substr(1, ret.hostname.size() - 2);

    if (to_integer(matches[2], ret.port, 10))

      return ret;

  } else {

    // If this was unsuccessful, then check if it's simply an unsigned 16-bit

    // integer, representing a port with an empty host.

    if (to_integer(host_and_port, ret.port, 10))

      return ret;

  }

  return llvm::createStringError(llvm::inconvertibleErrorCode(),

                                 "invalid host:port specification: '%s'",

                                 host_and_port.str().c_str());

}

IOObject::WaitableHandle Socket::GetWaitableHandle() {

  // TODO: On Windows, use WSAEventSelect

  return m_socket;

}

Status Socket::Read(void *buf, size_t &num_bytes) {

  Status error;

  int bytes_received = 0;

  do {

    bytes_received = ::recv(m_socket, static_cast<char *>(buf), num_bytes, 0);

  } while (bytes_received < 0 && 
IsInterrupted()1
);

  if (bytes_received < 0) {

    SetLastError(error);

    num_bytes = 0;

  } else

    num_bytes = bytes_received;

  Log *log = GetLog(LLDBLog::Communication);

  if (log) {

    LLDB_LOGF(log,

              "%p Socket::Read() (socket = %" PRIu64

              ", src = %p, src_len = %" PRIu64 ", flags = 0) => %" PRIi64

              " (error = %s)",

              static_cast<void *>(this), static_cast<uint64_t>(m_socket), buf,

              static_cast<uint64_t>(num_bytes),

              static_cast<int64_t>(bytes_received), error.AsCString());

  }

  return error;

}

Status Socket::Write(const void *buf, size_t &num_bytes) {

  const size_t src_len = num_bytes;

  Status error;

  int bytes_sent = 0;

  do {

    bytes_sent = Send(buf, num_bytes);

  } while (bytes_sent < 0 && 
IsInterrupted()0
);

  if (bytes_sent < 0) {

    SetLastError(error);

    num_bytes = 0;

  } else

    num_bytes = bytes_sent;

  Log *log = GetLog(LLDBLog::Communication);

  if (log) {

    LLDB_LOGF(log,

              "%p Socket::Write() (socket = %" PRIu64

              ", src = %p, src_len = %" PRIu64 ", flags = 0) => %" PRIi64

              " (error = %s)",

              static_cast<void *>(this), static_cast<uint64_t>(m_socket), buf,

              static_cast<uint64_t>(src_len),

              static_cast<int64_t>(bytes_sent), error.AsCString());

  }

  return error;

}

Status Socket::Close() {

  Status error;

  if (!IsValid() || 
!m_should_close_fd393
)

    return error;

  Log *log = GetLog(LLDBLog::Connection);

  LLDB_LOGF(log, "%p Socket::Close (fd = %" PRIu64 ")",

            static_cast<void *>(this), static_cast<uint64_t>(m_socket));

#if defined(_WIN32)

  bool success = closesocket(m_socket) == 0;

#else

  bool success = ::close(m_socket) == 0;

#endif

  // A reference to a FD was passed in, set it to an invalid value

  m_socket = kInvalidSocketValue;

  if (!success) {

    SetLastError(error);

  }

  return error;

}

int Socket::GetOption(int level, int option_name, int &option_value) {

  get_socket_option_arg_type option_value_p =

      reinterpret_cast<get_socket_option_arg_type>(&option_value);

  socklen_t option_value_size = sizeof(int);

  return ::getsockopt(m_socket, level, option_name, option_value_p,

                      &option_value_size);

}

int Socket::SetOption(int level, int option_name, int option_value) {

  set_socket_option_arg_type option_value_p =

      reinterpret_cast<get_socket_option_arg_type>(&option_value);

  return ::setsockopt(m_socket, level, option_name, option_value_p,

                      sizeof(option_value));

}

size_t Socket::Send(const void *buf, const size_t num_bytes) {

  return ::send(m_socket, static_cast<const char *>(buf), num_bytes, 0);

}

void Socket::SetLastError(Status &error) {

#if defined(_WIN32)

  error.SetError(::WSAGetLastError(), lldb::eErrorTypeWin32);

#else

  error.SetErrorToErrno();

#endif

}

NativeSocket Socket::CreateSocket(const int domain, const int type,

                                  const int protocol,

                                  bool child_processes_inherit, Status &error) {

  error.Clear();

  auto socket_type = type;

#ifdef SOCK_CLOEXEC

  if (!child_processes_inherit)

    socket_type |= SOCK_CLOEXEC;

#endif

  auto sock = ::socket(domain, socket_type, protocol);

  if (sock == kInvalidSocketValue)

    SetLastError(error);

  return sock;

}

NativeSocket Socket::AcceptSocket(NativeSocket sockfd, struct sockaddr *addr,

                                  socklen_t *addrlen,

                                  bool child_processes_inherit, Status &error) {

  error.Clear();

#if defined(ANDROID_USE_ACCEPT_WORKAROUND)

  // Hack:

  // This enables static linking lldb-server to an API 21 libc, but still

  // having it run on older devices. It is necessary because API 21 libc's

  // implementation of accept() uses the accept4 syscall(), which is not

  // available in older kernels. Using an older libc would fix this issue, but

  // introduce other ones, as the old libraries were quite buggy.

  int fd = syscall(__NR_accept, sockfd, addr, addrlen);

  if (fd >= 0 && !child_processes_inherit) {

    int flags = ::fcntl(fd, F_GETFD);

    if (flags != -1 && ::fcntl(fd, F_SETFD, flags | FD_CLOEXEC) != -1)

      return fd;

    SetLastError(error);

    close(fd);

  }

  return fd;

#elif defined(SOCK_CLOEXEC) && defined(HAVE_ACCEPT4)

  int flags = 0;

  if (!child_processes_inherit) {

    flags |= SOCK_CLOEXEC;

  }

  NativeSocket fd = llvm::sys::RetryAfterSignal(

      static_cast<NativeSocket>(-1), ::accept4, sockfd, addr, addrlen, flags);

#else

  NativeSocket fd = llvm::sys::RetryAfterSignal(

      static_cast<NativeSocket>(-1), ::accept, sockfd, addr, addrlen);

#endif

  if (fd == kInvalidSocketValue)

    SetLastError(error);

  return fd;

}

llvm::raw_ostream &lldb_private::operator<<(llvm::raw_ostream &OS,

                                            const Socket::HostAndPort &HP) {

  return OS << '[' << HP.hostname << ']' << ':' << HP.port;

}