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SocketDescriptor.cc

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/**************************************************************************
 Copyright (c) 2000-2001, Tony Garnock-Jones
 All rights reserved.

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 modification, are permitted provided that the following conditions are
 met:

     * Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

     * Redistributions in binary form must reproduce the above
       copyright notice, this list of conditions and the following
       disclaimer in the documentation and/or other materials provided
       with the distribution.

     * Neither the names of the copyright holders nor the names of this
       software's contributors may be used to endorse or promote
       products derived from this software without specific prior
       written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR
 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**************************************************************************/

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>

#ifdef __WIN32__
#include <winsock.h>
#else
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#endif

#include <FileDescriptor.h>
#include <SocketDescriptor.h>

#if defined(hpux) || defined(__WIN32__)
/* Hmm. Not strictly true. Curse socklen_t to the nether regions of hell. */
/* And Windows. */
typedef int socklen_t;
#endif

///////////////////////////////////////////////////////////////////////////

#ifdef __WIN32__

class Win32SocketManager {
public:
  Win32SocketManager() {
    WSADATA wsaData;
    int result = WSAStartup(1, &wsaData);
    if (result) {
      fprintf(stderr, "Could not initialise winsock (WSAStartup returned %d)\n",
              result);
      exit(1);
    }
  }

  ~Win32SocketManager() {
    WSACleanup();
  }
};

static Win32SocketManager win32SocketManager;

#endif  /* defined(__WIN32__) */

///////////////////////////////////////////////////////////////////////////

int SocketDescriptor::lowlevel_read(int fd, char *buf, int len) {
#ifdef __WIN32__
  int result = ::recv(getFd(), buf, len, 0);

  if (result != SOCKET_ERROR) {
    return result;
  }

  int sockerrno = WSAGetLastError();
  switch (sockerrno) {
    case WSAECONNRESET:
      // Effectively an end-of-file.
      return 0;

    case WSAEWOULDBLOCK:
      // Hmm. Sockets on Windows appear to indicate partial-data-availability
      // by returning nothing less than what you asked for.
      //
      // "Interesting" hack to make FileDescriptor::fillBuffer() return false.
      errno = EAGAIN;
      return -1;

    default:
      fprintf(stderr, "SocketDescriptor::lowlevel_read: Got WSAGetLastError of %d (0x%x)\n",
              sockerrno, sockerrno);
      return 0;
  }

#else
  return ::read(getFd(), buf, len);
#endif
}

int SocketDescriptor::lowlevel_write(int fd, char const *buf, int len) {
#ifdef linux
  return ::send(getFd(), buf, len, MSG_NOSIGNAL);
#else
# ifdef __WIN32__
  return ::send(getFd(), buf, len, 0);
# else
  return ::write(getFd(), buf, len);
# endif
#endif
}

#ifdef __WIN32__
int SocketDescriptor::lowlevel_close(int fd) {
  return ::closesocket(fd);
}
#endif

void SocketDescriptor::close() {
  shutdown(getFd(), 2);
  FileDescriptor::close();
}

///////////////////////////////////////////////////////////////////////////

static bool getAddrByName(string const &name, unsigned int &addr) {
#ifdef __WIN32__
  // Teach the windows resolver about dotted-quads.
  unsigned long dottedAddr = inet_addr(name.c_str());
  if (dottedAddr != INADDR_NONE) {
    addr = dottedAddr;
    return true;
  }
#endif

  struct hostent *he = gethostbyname(name.c_str());

  if (he == NULL)
    return false;

  addr = * (int *) he->h_addr_list[0];
  return true;
}

static string getNameByAddr(char const *addr) {
  struct hostent *h = gethostbyaddr(addr, 4, AF_INET);

  if (h == NULL) {
    char buf[20];
    sprintf(buf, "%u.%u.%u.%u",
            ((unsigned char *) addr)[0],
            ((unsigned char *) addr)[1],
            ((unsigned char *) addr)[2],
            ((unsigned char *) addr)[3]);
    return buf;
  }

  return h->h_name;
}

///////////////////////////////////////////////////////////////////////////

ClientSocketDescriptor::ClientSocketDescriptor(ref<FileDescriptorManager> const &_fdMgr,
                                               string const &_hostname, int _port)
  : SocketDescriptor(_fdMgr, socket(PF_INET, SOCK_STREAM, 0))
{
  if (!isOpen())
    throw Exception("Could not create socket in ClientSocketDescriptor ctor", errno);

  int sock = getFd();

  setRemoteAddr(_hostname, _port);

  unsigned int connectaddr;
  if (!getAddrByName(_hostname, connectaddr)) {
    close();
    throw Exception("Host " + _hostname + " not found in ClientSocketDescriptor ctor");
  }

  struct sockaddr_in addr;
  addr.sin_family = AF_INET;
  addr.sin_port = htons(_port);
  addr.sin_addr.s_addr = connectaddr;

  if (connect(sock, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
    int savedErrno = errno;
    close();
    throw Exception("Could not connect() in ClientSocketDescriptor ctor", savedErrno);
  }

  // We're connected. Save the remote address away.
  socklen_t addrlen = sizeof(addr);
  if (getsockname(sock, (struct sockaddr *) &addr, &addrlen) != -1) {
    setLocalAddr(getNameByAddr((char *) &addr.sin_addr.s_addr), ntohs(addr.sin_port));
  }
}

///////////////////////////////////////////////////////////////////////////

ServerSocketDescriptor::ServerSocketDescriptor(ref<FileDescriptorManager> const &_fdMgr,
                                               int _port = 0, string const &_hostname = "")
  : SocketDescriptor(_fdMgr, socket(PF_INET, SOCK_STREAM, 0))
{
  if (!isOpen())
    throw Exception("Could not create socket in ServerSocketDescriptor ctor", errno);

  int fd = getFd();

  {
    int i = 1;  // 1 == turn on the option
    // We don't care if this fails.
#ifdef __WIN32__
    setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &i, sizeof(i));
#else
    setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
#endif
  }

  unsigned int bindaddr;                // in network order
  unsigned int localaddr;

  if (_hostname != "") {
    // We have a name to bind to.
    // We should use getsockname() to find our local address.
    if (!getAddrByName(_hostname, bindaddr)) {
      close();
      throw Exception("Host " + _hostname + " not found in ServerSocketDescriptor ctor");
    }
    localaddr = bindaddr;
  } else {
    // We have no name to bind to - use INADDR_ANY
    // We should use gethostname() to find our local address.
    char buf[256];
    if (gethostname(buf, 256) < 0) {
      close();
      throw Exception("Could not determine local hostname using gethostname(2)");
    }

    bindaddr = INADDR_ANY;
    if (!getAddrByName(buf, localaddr)) {
      localaddr = INADDR_ANY;
    }
  }

  struct sockaddr_in sa;
  sa.sin_family = AF_INET;
  sa.sin_port = htons(_port);
  sa.sin_addr.s_addr = bindaddr;

  if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
    char nbuf[40];
    sprintf(nbuf, "%d", _port);
    close();
    throw Exception("Could not bind to " + _hostname + ":" + nbuf);
  }

  if (listen(fd, 50) < 0) {
    close();
    throw Exception("Could not listen on socket");
  }

  // Use getsockname() here to get the port number. We ignore the
  // address returned - it's already calculated as localaddr above.
  socklen_t socknamelen = sizeof(sa);

  if (getsockname(fd, (struct sockaddr *) &sa, &socknamelen) < 0) {
    close();
    throw Exception("Could not determine local ServerSocket name");
  }

  {
    char addrbuf[100];
    sprintf(addrbuf, "%u.%u.%u.%u:%d",
            ((unsigned char *) &localaddr)[0],
            ((unsigned char *) &localaddr)[1],
            ((unsigned char *) &localaddr)[2],
            ((unsigned char *) &localaddr)[3],
            ntohs(sa.sin_port));

    canonicalAddress = addrbuf;
    setLocalAddr(getNameByAddr((char *) &localaddr), ntohs(sa.sin_port));
  }
}

ref<SocketDescriptor> ServerSocketDescriptor::accept() {
  struct sockaddr_in sa;
  socklen_t salen = sizeof(sa);

  int newfd = ::accept(getFd(), (struct sockaddr *) &sa, &salen);
  if (newfd == -1) {
    throw Exception("Could not accept() on ServerSocket", errno);
  }

  ref<SocketDescriptor> sock = new SocketDescriptor(getFdMgr(), newfd);
  sock->setRemoteAddr(getNameByAddr((char *) &sa.sin_addr.s_addr), ntohs(sa.sin_port));

  salen = sizeof(sa);
  if (getsockname(sock->getFd(), (struct sockaddr *) &sa, &salen) == -1) {
    throw Exception("Could not determine local ServerSocket name");
  }

  sock->setLocalAddr(getNameByAddr((char *) &sa.sin_addr.s_addr), ntohs(sa.sin_port));

  return sock;
}

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