path: root/vio/viosocket.c

/* Copyright (C) 2000 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/*
  Note that we can't have assertion on file descriptors;  The reason for
  this is that during mysql shutdown, another thread can close a file
  we are working on.  In this case we should just return read errors from
  the file descriptior.
*/

#include "vio_priv.h"

int vio_errno(Vio *vio __attribute__((unused)))
{
  return socket_errno;		/* On Win32 this mapped to WSAGetLastError() */
}


size_t vio_read(Vio * vio, uchar* buf, size_t size)
{
  size_t r;
  DBUG_ENTER("vio_read");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %u", vio->sd, (long) buf,
                       (uint) size));

  /* Ensure nobody uses vio_read_buff and vio_read simultaneously */
  DBUG_ASSERT(vio->read_end == vio->read_pos);
#ifdef __WIN__
  r = recv(vio->sd, buf, size,0);
#else
  errno=0;					/* For linux */
  r = read(vio->sd, buf, size);
#endif /* __WIN__ */
#ifndef DBUG_OFF
  if (r == (size_t) -1)
  {
    DBUG_PRINT("vio_error", ("Got error %d during read",errno));
  }
#endif /* DBUG_OFF */
  DBUG_PRINT("exit", ("%ld", (long) r));
  DBUG_RETURN(r);
}


/*
  Buffered read: if average read size is small it may
  reduce number of syscalls.
*/

size_t vio_read_buff(Vio *vio, uchar* buf, size_t size)
{
  size_t rc;
#define VIO_UNBUFFERED_READ_MIN_SIZE 2048
  DBUG_ENTER("vio_read_buff");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %u", vio->sd, (long) buf,
                       (uint) size));

  if (vio->read_pos < vio->read_end)
  {
    rc= min((size_t) (vio->read_end - vio->read_pos), size);
    memcpy(buf, vio->read_pos, rc);
    vio->read_pos+= rc;
    /*
      Do not try to read from the socket now even if rc < size:
      vio_read can return -1 due to an error or non-blocking mode, and
      the safest way to handle it is to move to a separate branch.
    */
  }
  else if (size < VIO_UNBUFFERED_READ_MIN_SIZE)
  {
    rc= vio_read(vio, (uchar*) vio->read_buffer, VIO_READ_BUFFER_SIZE);
    if (rc != 0 && rc != (size_t) -1)
    {
      if (rc > size)
      {
        vio->read_pos= vio->read_buffer + size;
        vio->read_end= vio->read_buffer + rc;
        rc= size;
      }
      memcpy(buf, vio->read_buffer, rc);
    }
  }
  else
    rc= vio_read(vio, buf, size);
  DBUG_RETURN(rc);
#undef VIO_UNBUFFERED_READ_MIN_SIZE
}


size_t vio_write(Vio * vio, const uchar* buf, size_t size)
{
  size_t r;
  DBUG_ENTER("vio_write");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %u", vio->sd, (long) buf,
                       (uint) size));
#ifdef __WIN__
  r = send(vio->sd, buf, size,0);
#else
  r = write(vio->sd, buf, size);
#endif /* __WIN__ */
#ifndef DBUG_OFF
  if (r == (size_t) -1)
  {
    DBUG_PRINT("vio_error", ("Got error on write: %d",socket_errno));
  }
#endif /* DBUG_OFF */
  DBUG_PRINT("exit", ("%u", (uint) r));
  DBUG_RETURN(r);
}

int vio_blocking(Vio * vio __attribute__((unused)), my_bool set_blocking_mode,
		 my_bool *old_mode)
{
  int r=0;
  DBUG_ENTER("vio_blocking");

  *old_mode= test(!(vio->fcntl_mode & O_NONBLOCK));
  DBUG_PRINT("enter", ("set_blocking_mode: %d  old_mode: %d",
		       (int) set_blocking_mode, (int) *old_mode));

#if !defined(__WIN__)
#if !defined(NO_FCNTL_NONBLOCK)
  if (vio->sd >= 0)
  {
    int old_fcntl=vio->fcntl_mode;
    if (set_blocking_mode)
      vio->fcntl_mode &= ~O_NONBLOCK; /* clear bit */
    else
      vio->fcntl_mode |= O_NONBLOCK; /* set bit */
    if (old_fcntl != vio->fcntl_mode)
    {
      r= fcntl(vio->sd, F_SETFL, vio->fcntl_mode);
      if (r == -1)
      {
        DBUG_PRINT("info", ("fcntl failed, errno %d", errno));
        vio->fcntl_mode= old_fcntl;
      }
    }
  }
#else
  r= set_blocking_mode ? 0 : 1;
#endif /* !defined(NO_FCNTL_NONBLOCK) */
#else /* !defined(__WIN__) */
  if (vio->type != VIO_TYPE_NAMEDPIPE && vio->type != VIO_TYPE_SHARED_MEMORY)
  { 
    ulong arg;
    int old_fcntl=vio->fcntl_mode;
    if (set_blocking_mode)
    {
      arg = 0;
      vio->fcntl_mode &= ~O_NONBLOCK; /* clear bit */
    }
    else
    {
      arg = 1;
      vio->fcntl_mode |= O_NONBLOCK; /* set bit */
    }
    if (old_fcntl != vio->fcntl_mode)
      r = ioctlsocket(vio->sd,FIONBIO,(void*) &arg);
  }
  else
    r=  test(!(vio->fcntl_mode & O_NONBLOCK)) != set_blocking_mode;
#endif /* !defined(__WIN__) */
  DBUG_PRINT("exit", ("%d", r));
  DBUG_RETURN(r);
}

my_bool
vio_is_blocking(Vio * vio)
{
  my_bool r;
  DBUG_ENTER("vio_is_blocking");
  r = !(vio->fcntl_mode & O_NONBLOCK);
  DBUG_PRINT("exit", ("%d", (int) r));
  DBUG_RETURN(r);
}


int vio_fastsend(Vio * vio __attribute__((unused)))
{
  int r=0;
  DBUG_ENTER("vio_fastsend");

#if defined(IPTOS_THROUGHPUT)
  {
    int tos = IPTOS_THROUGHPUT;
    r= setsockopt(vio->sd, IPPROTO_IP, IP_TOS, (void *) &tos, sizeof(tos));
  }
#endif                                    /* IPTOS_THROUGHPUT */
  if (!r)
  {
#ifdef __WIN__
    BOOL nodelay= 1;
#else
    int nodelay = 1;
#endif

    r= setsockopt(vio->sd, IPPROTO_TCP, TCP_NODELAY,
                  IF_WIN((const char*), (void*)) &nodelay,
                  sizeof(nodelay));

  }
  if (r)
  {
    DBUG_PRINT("warning", ("Couldn't set socket option for fast send"));
    r= -1;
  }
  DBUG_PRINT("exit", ("%d", r));
  DBUG_RETURN(r);
}

int vio_keepalive(Vio* vio, my_bool set_keep_alive)
{
  int r=0;
  uint opt = 0;
  DBUG_ENTER("vio_keepalive");
  DBUG_PRINT("enter", ("sd: %d  set_keep_alive: %d", vio->sd, (int)
		       set_keep_alive));
  if (vio->type != VIO_TYPE_NAMEDPIPE)
  {
    if (set_keep_alive)
      opt = 1;
    r = setsockopt(vio->sd, SOL_SOCKET, SO_KEEPALIVE, (char *) &opt,
		   sizeof(opt));
  }
  DBUG_RETURN(r);
}


my_bool
vio_should_retry(Vio * vio)
{
  int en = socket_errno;
  /*
    man 2 read write
      EAGAIN or EWOULDBLOCK when a socket is a non-blocking mode means
      that the read/write would block.
    man 7 socket
      EAGAIN or EWOULDBLOCK when a socket is in a blocking mode means
      that the corresponding receiving or sending timeout was reached.
  */
  return  en == SOCKET_EINTR ||
          (!vio_is_blocking(vio) &&
            (en == SOCKET_EAGAIN || en == SOCKET_EWOULDBLOCK));
}


my_bool
vio_was_interrupted(Vio *vio __attribute__((unused)))
{
  int en= socket_errno;
  return (en == SOCKET_EAGAIN || en == SOCKET_EINTR ||
	  en == SOCKET_EWOULDBLOCK || en == SOCKET_ETIMEDOUT);
}


int vio_close(Vio * vio)
{
  int r=0;
  DBUG_ENTER("vio_close");

 if (vio->type != VIO_CLOSED)
  {
    DBUG_ASSERT(vio->type ==  VIO_TYPE_TCPIP ||
      vio->type == VIO_TYPE_SOCKET ||
      vio->type == VIO_TYPE_SSL);

    DBUG_ASSERT(vio->sd >= 0);
    if (shutdown(vio->sd, SHUT_RDWR))
      r= -1;
    if (closesocket(vio->sd))
      r= -1;
  }
  if (r)
  {
    DBUG_PRINT("vio_error", ("close() failed, error: %d",socket_errno));
    /* FIXME: error handling (not critical for MySQL) */
  }
  vio->type= VIO_CLOSED;
  vio->sd=   -1;
  DBUG_RETURN(r);
}


const char *vio_description(Vio * vio)
{
  return vio->desc;
}

enum enum_vio_type vio_type(Vio* vio)
{
  return vio->type;
}

my_socket vio_fd(Vio* vio)
{
  return vio->sd;
}

/**
  Convert a sock-address (AF_INET or AF_INET6) into the "normalized" form,
  which is the IPv4 form for IPv4-mapped or IPv4-compatible IPv6 addresses.

  @note Background: when IPv4 and IPv6 are used simultaneously, IPv4
  addresses may be written in a form of IPv4-mapped or IPv4-compatible IPv6
  addresses. That means, one address (a.b.c.d) can be written in three forms:
    - IPv4: a.b.c.d;
    - IPv4-compatible IPv6: ::a.b.c.d;
    - IPv4-mapped IPv4: ::ffff:a.b.c.d;

  Having three forms of one address makes it a little difficult to compare
  addresses with each other (the IPv4-compatible IPv6-address of foo.bar
  will be different from the IPv4-mapped IPv6-address of foo.bar).

  @note This function can be made public when it's needed.

  @param src        [in] source IP address (AF_INET or AF_INET6).
  @param src_length [in] length of the src.
  @param dst        [out] a buffer to store normalized IP address
                          (sockaddr_storage).
  @param dst_length [out] actual length of the normalized IP address.
*/
static void vio_get_normalized_ip(const struct sockaddr *src,
                                  int src_length,
                                  struct sockaddr *dst,
                                  int *dst_length)
{
  switch (src->sa_family) {
  case AF_INET:
    memcpy(dst, src, src_length);
    *dst_length= src_length;
    break;

#ifdef HAVE_IPV6
  case AF_INET6:
  {
    const struct sockaddr_in6 *src_addr6= (const struct sockaddr_in6 *) src;
    const struct in6_addr *src_ip6= &(src_addr6->sin6_addr);
    const uint32 *src_ip6_int32= (uint32 *) src_ip6->s6_addr;

    if (IN6_IS_ADDR_V4MAPPED(src_ip6) || IN6_IS_ADDR_V4COMPAT(src_ip6))
    {
      struct sockaddr_in *dst_ip4= (struct sockaddr_in *) dst;

      /*
        This is an IPv4-mapped or IPv4-compatible IPv6 address. It should
        be converted to the IPv4 form.
      */

      *dst_length= sizeof (struct sockaddr_in);

      memset(dst_ip4, 0, *dst_length);
      dst_ip4->sin_family= AF_INET;
      dst_ip4->sin_port= src_addr6->sin6_port;

      /*
        In an IPv4 mapped or compatible address, the last 32 bits represent
        the IPv4 address. The byte orders for IPv6 and IPv4 addresses are
        the same, so a simple copy is possible.
      */
      dst_ip4->sin_addr.s_addr= src_ip6_int32[3];
    }
    else
    {
      /* This is a "native" IPv6 address. */

      memcpy(dst, src, src_length);
      *dst_length= src_length;
    }

    break;
  }
#endif /* HAVE_IPV6 */
  }
}


/**
  Return the normalized IP address string for a sock-address.

  The idea is to return an IPv4-address for an IPv4-mapped and
  IPv4-compatible IPv6 address.

  The function writes the normalized IP address to the given buffer.
  The buffer should have enough space, otherwise error flag is returned.
  The system constant INET6_ADDRSTRLEN can be used to reserve buffers of
  the right size.

  @param addr           [in]  sockaddr object (AF_INET or AF_INET6).
  @param addr_length    [in]  length of the addr.
  @param ip_string      [out] buffer to write normalized IP address.
  @param ip_string_size [in]  size of the ip_string.

  @return Error status.
  @retval TRUE in case of error (the ip_string buffer is not enough).
  @retval FALSE on success.
*/

my_bool vio_get_normalized_ip_string(const struct sockaddr *addr,
                                     int addr_length,
                                     char *ip_string,
                                     size_t ip_string_size)
{
  struct sockaddr_storage norm_addr_storage;
  struct sockaddr *norm_addr= (struct sockaddr *) &norm_addr_storage;
  int norm_addr_length;
  int err_code;

  vio_get_normalized_ip(addr, addr_length, norm_addr, &norm_addr_length);

  err_code= vio_getnameinfo(norm_addr, ip_string, ip_string_size, NULL, 0,
                            NI_NUMERICHOST);

  if (!err_code)
    return FALSE;

  DBUG_PRINT("error", ("getnameinfo() failed with %d (%s).",
                       (int) err_code,
                       (const char *) gai_strerror(err_code)));
  return TRUE;
}


/**
  Return IP address and port of a VIO client socket.

  The function returns an IPv4 address if IPv6 support is disabled.

  The function returns an IPv4 address if the client socket is associated
  with an IPv4-compatible or IPv4-mapped IPv6 address. Otherwise, the native
  IPv6 address is returned.
*/

my_bool vio_peer_addr(Vio *vio, char *ip_buffer, uint16 *port,
                      size_t ip_buffer_size)
{
  DBUG_ENTER("vio_peer_addr");
  DBUG_PRINT("enter", ("Client socked fd: %d", (int) vio->sd));

  if (vio->localhost)
  {
    /*
      Initialize vio->remote and vio->addLen. Set vio->remote to IPv4 loopback
      address.
    */
    struct in_addr *ip4= &((struct sockaddr_in *) &(vio->remote))->sin_addr;

    vio->remote.ss_family= AF_INET;
    vio->addrLen= sizeof (struct sockaddr_in);

    ip4->s_addr= htonl(INADDR_LOOPBACK);

    /* Initialize ip_buffer and port. */

    strmov(ip_buffer, "127.0.0.1");
    *port= 0;
  }
  else
  {
    int err_code;
    char port_buffer[NI_MAXSERV];

    struct sockaddr_storage addr_storage;
    struct sockaddr *addr= (struct sockaddr *) &addr_storage;
    size_socket addr_length= sizeof (addr_storage);

    /* Get sockaddr by socked fd. */

    err_code= getpeername(vio->sd, addr, &addr_length);

    if (err_code)
    {
      DBUG_PRINT("exit", ("getpeername() gave error: %d", socket_errno));
      DBUG_RETURN(TRUE);
    }

    /* Normalize IP address. */

    vio_get_normalized_ip(addr, addr_length,
                          (struct sockaddr *) &vio->remote, &vio->addrLen);

    /* Get IP address & port number. */

    err_code= vio_getnameinfo((struct sockaddr *) &vio->remote,
                              ip_buffer, ip_buffer_size,
                              port_buffer, NI_MAXSERV,
                              NI_NUMERICHOST | NI_NUMERICSERV);

    if (err_code)
    {
      DBUG_PRINT("exit", ("getnameinfo() gave error: %s",
                          gai_strerror(err_code)));
      DBUG_RETURN(TRUE);
    }

    *port= (uint16) strtol(port_buffer, NULL, 10);
  }

  DBUG_PRINT("exit", ("Client IP address: %s; port: %d",
                      (const char *) ip_buffer,
                      (int) *port));
  DBUG_RETURN(FALSE);
}


/**
  Indicate whether there is data to read on a given socket.

  @note An exceptional condition event and/or errors are
        interpreted as if there is data to read.

  @param sd       A connected socket.
  @param timeout  Maximum time in seconds to poll.

  @retval FALSE   There is data to read.
  @retval TRUE    There is no data to read.
*/

static my_bool socket_poll_read(my_socket sd, uint timeout)
{
#ifdef __WIN__
  int res;
  my_socket fd= sd;
  fd_set readfds, errorfds;
  struct timeval tm;
  DBUG_ENTER("socket_poll_read");
  tm.tv_sec= timeout;
  tm.tv_usec= 0;
  FD_ZERO(&readfds);
  FD_ZERO(&errorfds);
  FD_SET(fd, &readfds);
  FD_SET(fd, &errorfds);
  /* The first argument is ignored on Windows, so a conversion to int is OK */
  if ((res= select((int) fd, &readfds, NULL, &errorfds, &tm) <= 0))
  {
    DBUG_RETURN(res < 0 ? 0 : 1);
  }
  res= FD_ISSET(fd, &readfds) || FD_ISSET(fd, &errorfds);
  DBUG_RETURN(!res);
#elif defined(HAVE_POLL)
  struct pollfd fds;
  int res;
  DBUG_ENTER("socket_poll_read");
  fds.fd=sd;
  fds.events=POLLIN;
  fds.revents=0;
  if ((res=poll(&fds,1,(int) timeout*1000)) <= 0)
  {
    DBUG_RETURN(res < 0 ? 0 : 1);		/* Don't return 1 on errors */
  }
  DBUG_RETURN(fds.revents & (POLLIN | POLLERR | POLLHUP) ? 0 : 1);
#else
  return 0;
#endif
}


/**
  Retrieve the amount of data that can be read from a socket.

  @param vio          A VIO object.
  @param bytes[out]   The amount of bytes available.

  @retval FALSE   Success.
  @retval TRUE    Failure.
*/

static my_bool socket_peek_read(Vio *vio, uint *bytes)
{
#ifdef __WIN__
  int len;
  if (ioctlsocket(vio->sd, FIONREAD, &len))
    return TRUE;
  *bytes= len;
  return FALSE;
#elif FIONREAD_IN_SYS_IOCTL
  int len;
  if (ioctl(vio->sd, FIONREAD, &len) < 0)
    return TRUE;
  *bytes= len;
  return FALSE;
#else
  char buf[1024];
  ssize_t res= recv(vio->sd, &buf, sizeof(buf), MSG_PEEK);
  if (res < 0)
    return TRUE;
  *bytes= res;
  return FALSE;
#endif
}


/**
  Indicate whether there is data to read on a given socket.

  @remark Errors are interpreted as if there is data to read.

  @param sd       A connected socket.
  @param timeout  Maximum time in seconds to wait.

  @retval FALSE   There is data (or EOF) to read. Also FALSE if error.
  @retval TRUE    There is _NO_ data to read or timed out.
*/

my_bool vio_poll_read(Vio *vio, uint timeout)
{
  my_socket sd= vio->sd;
  DBUG_ENTER("vio_poll_read");
#ifdef HAVE_OPENSSL
  if (vio->type == VIO_TYPE_SSL)
    sd= SSL_get_fd((SSL*) vio->ssl_arg);
#endif
  DBUG_RETURN(socket_poll_read(sd, timeout));
}


/**
  Determine if the endpoint of a connection is still available.

  @remark The socket is assumed to be disconnected if an EOF
          condition is encountered.

  @param vio      The VIO object.

  @retval TRUE    EOF condition not found.
  @retval FALSE   EOF condition is signaled.
*/

my_bool vio_is_connected(Vio *vio)
{
  uint bytes= 0;
  DBUG_ENTER("vio_is_connected");

  /* In the presence of errors the socket is assumed to be connected. */

  /*
    The first step of detecting a EOF condition is veryfing
    whether there is data to read. Data in this case would
    be the EOF.
  */
  if (vio_poll_read(vio, 0))
    DBUG_RETURN(TRUE);

  /*
    The second step is read() or recv() from the socket returning
    0 (EOF). Unfortunelly, it's not possible to call read directly
    as we could inadvertently read meaningful connection data.
    Simulate a read by retrieving the number of bytes available to
    read -- 0 meaning EOF.
  */
  if (socket_peek_read(vio, &bytes))
    DBUG_RETURN(TRUE);

#ifdef HAVE_OPENSSL
  /* There might be buffered data at the SSL layer. */
  if (!bytes && vio->type == VIO_TYPE_SSL)
    bytes= SSL_pending((SSL*) vio->ssl_arg);
#endif

  DBUG_RETURN(bytes ? TRUE : FALSE);
}


void vio_timeout(Vio *vio, uint which, uint timeout)
{
#if defined(SO_SNDTIMEO) && defined(SO_RCVTIMEO)
  int r;
  DBUG_ENTER("vio_timeout");

  {
#ifdef __WIN__
  /* Windows expects time in milliseconds as int */
  int wait_timeout= (int) timeout * 1000;
#else
  /* POSIX specifies time as struct timeval. */
  struct timeval wait_timeout;
  wait_timeout.tv_sec= timeout;
  wait_timeout.tv_usec= 0;
#endif

  r= setsockopt(vio->sd, SOL_SOCKET, which ? SO_SNDTIMEO : SO_RCVTIMEO,
                IF_WIN((const char*), (const void*))&wait_timeout,
                sizeof(wait_timeout));

  }

  if (r != 0)
    DBUG_PRINT("error", ("setsockopt failed: %d, errno: %d", r, socket_errno));

  DBUG_VOID_RETURN;
#else
/*
  Platforms not suporting setting of socket timeout should either use
  thr_alarm or just run without read/write timeout(s)
*/
#endif
}


#ifdef __WIN__

/*
  Finish pending IO on pipe. Honor wait timeout
*/
static size_t pipe_complete_io(Vio* vio, char* buf, size_t size, DWORD timeout_ms)
{
  DWORD length;
  DWORD ret;

  DBUG_ENTER("pipe_complete_io");

  ret= WaitForSingleObject(vio->pipe_overlapped.hEvent, timeout_ms);
  /*
    WaitForSingleObjects will normally return WAIT_OBJECT_O (success, IO completed)
    or WAIT_TIMEOUT.
  */
  if(ret != WAIT_OBJECT_0)
  {
    CancelIo(vio->hPipe);
    DBUG_PRINT("error",("WaitForSingleObject() returned  %d", ret));
    DBUG_RETURN((size_t)-1);
  }

  if (!GetOverlappedResult(vio->hPipe,&(vio->pipe_overlapped),&length, FALSE))
  {
    DBUG_PRINT("error",("GetOverlappedResult() returned last error  %d", 
      GetLastError()));
    DBUG_RETURN((size_t)-1);
  }

  DBUG_RETURN(length);
}


size_t vio_read_pipe(Vio * vio, uchar *buf, size_t size)
{
  DWORD bytes_read;
  size_t retval;
  DBUG_ENTER("vio_read_pipe");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %u", vio->sd, (long) buf,
                       (uint) size));

  if (ReadFile(vio->hPipe, buf, (DWORD)size, &bytes_read,
      &(vio->pipe_overlapped)))
  {
    retval= bytes_read;
  }
  else
  {
    if (GetLastError() != ERROR_IO_PENDING)
    {
      DBUG_PRINT("error",("ReadFile() returned last error %d",
        GetLastError()));
      DBUG_RETURN((size_t)-1);
    }
    retval= pipe_complete_io(vio, buf, size,vio->read_timeout_ms);
  }

  DBUG_PRINT("exit", ("%lld", (longlong)retval));
  DBUG_RETURN(retval);
}


size_t vio_write_pipe(Vio * vio, const uchar* buf, size_t size)
{
  DWORD bytes_written;
  size_t retval;
  DBUG_ENTER("vio_write_pipe");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %u", vio->sd, (long) buf,
                       (uint) size));

  if (WriteFile(vio->hPipe, buf, (DWORD)size, &bytes_written, 
      &(vio->pipe_overlapped)))
  {
    retval= bytes_written;
  }
  else
  {
    if (GetLastError() != ERROR_IO_PENDING)
    {
      DBUG_PRINT("vio_error",("WriteFile() returned last error %d",
        GetLastError()));
      DBUG_RETURN((size_t)-1);
    }
    retval= pipe_complete_io(vio, (char *)buf, size, vio->write_timeout_ms);
  }

  DBUG_PRINT("exit", ("%lld", (longlong)retval));
  DBUG_RETURN(retval);
}


my_bool vio_is_connected_pipe(Vio *vio)
{
  if (PeekNamedPipe(vio->hPipe, NULL, 0, NULL, NULL, NULL))
    return TRUE;
  else
    return (GetLastError() != ERROR_BROKEN_PIPE);
}


int vio_close_pipe(Vio * vio)
{
  int r;
  DBUG_ENTER("vio_close_pipe");

  CancelIo(vio->hPipe);
  CloseHandle(vio->pipe_overlapped.hEvent);
  DisconnectNamedPipe(vio->hPipe);
  r= CloseHandle(vio->hPipe);
  if (r)
  {
    DBUG_PRINT("vio_error", ("close() failed, error: %d",GetLastError()));
    /* FIXME: error handling (not critical for MySQL) */
  }
  vio->type= VIO_CLOSED;
  vio->sd=   -1;
  DBUG_RETURN(r);
}


void vio_win32_timeout(Vio *vio, uint which , uint timeout_sec)
{
    DWORD timeout_ms;
    /*
      Windows is measuring timeouts in milliseconds. Check for possible int 
      overflow.
    */
    if (timeout_sec > UINT_MAX/1000)
      timeout_ms= INFINITE;
    else
      timeout_ms= timeout_sec * 1000;

    /* which == 1 means "write", which == 0 means "read".*/
    if(which)
      vio->write_timeout_ms= timeout_ms;
    else
      vio->read_timeout_ms= timeout_ms;
}


#ifdef HAVE_SMEM

size_t vio_read_shared_memory(Vio * vio, uchar* buf, size_t size)
{
  size_t length;
  size_t remain_local;
  char *current_postion;
  HANDLE events[2];

  DBUG_ENTER("vio_read_shared_memory");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %d", vio->sd, (long) buf,
                       size));

  remain_local = size;
  current_postion=buf;

  events[0]= vio->event_server_wrote;
  events[1]= vio->event_conn_closed;

  do
  {
    if (vio->shared_memory_remain == 0)
    {
      /*
        WaitForMultipleObjects can return next values:
         WAIT_OBJECT_0+0 - event from vio->event_server_wrote
         WAIT_OBJECT_0+1 - event from vio->event_conn_closed. We can't read
		           anything
         WAIT_ABANDONED_0 and WAIT_TIMEOUT - fail.  We can't read anything
      */
      if (WaitForMultipleObjects(array_elements(events), events, FALSE,
                                 vio->read_timeout_ms) != WAIT_OBJECT_0)
      {
        DBUG_RETURN(-1);
      };

      vio->shared_memory_pos = vio->handle_map;
      vio->shared_memory_remain = uint4korr((ulong*)vio->shared_memory_pos);
      vio->shared_memory_pos+=4;
    }

    length = size;

    if (vio->shared_memory_remain < length)
       length = vio->shared_memory_remain;
    if (length > remain_local)
       length = remain_local;

    memcpy(current_postion,vio->shared_memory_pos,length);

    vio->shared_memory_remain-=length;
    vio->shared_memory_pos+=length;
    current_postion+=length;
    remain_local-=length;

    if (!vio->shared_memory_remain)
    {
      if (!SetEvent(vio->event_client_read))
        DBUG_RETURN(-1);
    }
  } while (remain_local);
  length = size;

  DBUG_PRINT("exit", ("%lu", (ulong) length));
  DBUG_RETURN(length);
}


size_t vio_write_shared_memory(Vio * vio, const uchar* buf, size_t size)
{
  size_t length, remain, sz;
  HANDLE pos;
  const uchar *current_postion;
  HANDLE events[2];

  DBUG_ENTER("vio_write_shared_memory");
  DBUG_PRINT("enter", ("sd: %d  buf: 0x%lx  size: %d", vio->sd, (long) buf,
                       size));

  remain = size;
  current_postion = buf;

  events[0]= vio->event_server_read;
  events[1]= vio->event_conn_closed;

  while (remain != 0)
  {
    if (WaitForMultipleObjects(array_elements(events), events, FALSE,
                               vio->write_timeout_ms) != WAIT_OBJECT_0)
    {
      DBUG_RETURN((size_t) -1);
    }

    sz= (remain > shared_memory_buffer_length ? shared_memory_buffer_length :
         remain);

    int4store(vio->handle_map,sz);
    pos = vio->handle_map + 4;
    memcpy(pos,current_postion,sz);
    remain-=sz;
    current_postion+=sz;
    if (!SetEvent(vio->event_client_wrote))
      DBUG_RETURN((size_t) -1);
  }
  length = size;

  DBUG_PRINT("exit", ("%lu", (ulong) length));
  DBUG_RETURN(length);
}


my_bool vio_is_connected_shared_memory(Vio *vio)
{
  return (WaitForSingleObject(vio->event_conn_closed, 0) != WAIT_OBJECT_0);
}


/**
 Close shared memory and DBUG_PRINT any errors that happen on closing.
 @return Zero if all closing functions succeed, and nonzero otherwise.
*/
int vio_close_shared_memory(Vio * vio)
{
  int error_count= 0;
  DBUG_ENTER("vio_close_shared_memory");
  if (vio->type != VIO_CLOSED)
  {
    /*
      Set event_conn_closed for notification of both client and server that
      connection is closed
    */
    SetEvent(vio->event_conn_closed);
    /*
      Close all handlers. UnmapViewOfFile and CloseHandle return non-zero
      result if they are success.
    */
    if (UnmapViewOfFile(vio->handle_map) == 0) 
    {
      error_count++;
      DBUG_PRINT("vio_error", ("UnmapViewOfFile() failed"));
    }
    if (CloseHandle(vio->event_server_wrote) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->esw) failed"));
    }
    if (CloseHandle(vio->event_server_read) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->esr) failed"));
    }
    if (CloseHandle(vio->event_client_wrote) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->ecw) failed"));
    }
    if (CloseHandle(vio->event_client_read) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->ecr) failed"));
    }
    if (CloseHandle(vio->handle_file_map) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->hfm) failed"));
    }
    if (CloseHandle(vio->event_conn_closed) == 0)
    {
      error_count++;
      DBUG_PRINT("vio_error", ("CloseHandle(vio->ecc) failed"));
    }
  }
  vio->type= VIO_CLOSED;
  vio->sd=   -1;
  DBUG_RETURN(error_count);
}
#endif /* HAVE_SMEM */
#endif /* __WIN__ */


/**
  Number of bytes in the read buffer.

  @return number of bytes in the read buffer or < 0 if error.
*/

ssize_t vio_pending(Vio *vio)
{
#ifdef HAVE_OPENSSL
  SSL *ssl= (SSL*) vio->ssl_arg;
#endif

  if (vio->read_pos < vio->read_end)
    return vio->read_end - vio->read_pos;

#ifdef HAVE_OPENSSL
  if (ssl)
    return SSL_pending(ssl);
#endif

  return 0;
}


/**
  This is a wrapper for the system getnameinfo(), because different OS
  differ in the getnameinfo() implementation. For instance, Solaris 10
  requires that the 2nd argument (salen) must match the actual size of the
  struct sockaddr_storage passed to it.
*/

int vio_getnameinfo(const struct sockaddr *sa,
                    char *hostname, size_t hostname_size,
                    char *port, size_t port_size,
                    int flags)
{
  int sa_length= 0;

  switch (sa->sa_family) {
  case AF_INET:
    sa_length= sizeof (struct sockaddr_in);
    break;

#ifdef HAVE_IPV6
  case AF_INET6:
    sa_length= sizeof (struct sockaddr_in6);
    break;
#endif /* HAVE_IPV6 */
  }

  return getnameinfo(sa, sa_length,
                     hostname, hostname_size,
                     port, port_size,
                     flags);
}