MGMDB/MySQL/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 __attribute__((unused)))
{
  int en = socket_errno;
  return (en == SOCKET_EAGAIN || en == SOCKET_EINTR ||
	  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;
}


my_bool vio_peer_addr(Vio * vio, char *buf, uint16 *port)
{
  DBUG_ENTER("vio_peer_addr");
  DBUG_PRINT("enter", ("sd: %d", vio->sd));
  if (vio->localhost)
  {
    strmov(buf,"127.0.0.1");
    *port= 0;
  }
  else
  {
    size_socket addrLen = sizeof(vio->remote);
    if (getpeername(vio->sd, (struct sockaddr *) (&vio->remote),
		    &addrLen) != 0)
    {
      DBUG_PRINT("exit", ("getpeername gave error: %d", socket_errno));
      DBUG_RETURN(1);
    }
    my_inet_ntoa(vio->remote.sin_addr,buf);
    *port= ntohs(vio->remote.sin_port);
  }
  DBUG_PRINT("exit", ("addr: %s", buf));
  DBUG_RETURN(0);
}


/*
  Get in_addr for a TCP/IP connection

  SYNOPSIS
    vio_in_addr()
    vio		vio handle
    in		put in_addr here

  NOTES
    one must call vio_peer_addr() before calling this one
*/

void vio_in_addr(Vio *vio, struct in_addr *in)
{
  DBUG_ENTER("vio_in_addr");
  if (vio->localhost)
    bzero((char*) in, sizeof(*in));
  else
    *in=vio->remote.sin_addr;
  DBUG_VOID_RETURN;
}


/* Return 0 if there is data to be read */

my_bool vio_poll_read(Vio *vio,uint timeout)
{
#ifndef HAVE_POLL
  return 0;
#else
  struct pollfd fds;
  int res;
  DBUG_ENTER("vio_poll");
  fds.fd=vio->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 ? 0 : 1);
#endif
}


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));

  }

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

  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 int pipe_complete_io(Vio* vio, char* buf, size_t size, DWORD timeout_millis)
{
  DWORD length;
  DWORD ret;

  DBUG_ENTER("pipe_complete_io");

  ret= WaitForSingleObject(vio->pipe_overlapped.hEvent, timeout_millis);
  /*
    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(-1);
  }

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

  DBUG_RETURN(length);
}


size_t vio_read_pipe(Vio * vio, uchar *buf, size_t size)
{
  DWORD bytes_read;
  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)))
  {
    if (GetLastError() != ERROR_IO_PENDING)
    {
      DBUG_PRINT("error",("ReadFile() returned last error %d",
        GetLastError()));
      DBUG_RETURN((size_t)-1);
    }
    bytes_read= pipe_complete_io(vio, buf, size,vio->read_timeout_millis);
  }

  DBUG_PRINT("exit", ("%d", bytes_read));
  DBUG_RETURN(bytes_read);
}


size_t vio_write_pipe(Vio * vio, const uchar* buf, size_t size)
{
  DWORD bytes_written;
  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)))
  {
    if (GetLastError() != ERROR_IO_PENDING)
    {
      DBUG_PRINT("vio_error",("WriteFile() returned last error %d",
        GetLastError()));
      DBUG_RETURN((size_t)-1);
    }
    bytes_written = pipe_complete_io(vio, (char *)buf, size, 
        vio->write_timeout_millis);
  }

  DBUG_PRINT("exit", ("%d", bytes_written));
  DBUG_RETURN(bytes_written);
}


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

  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_millis;
    /*
      Windows is measuring timeouts in milliseconds. Check for possible int 
      overflow.
    */
    if (timeout_sec > UINT_MAX/1000)
      timeout_millis= INFINITE;
    else
      timeout_millis= timeout_sec * 1000;

    /* which == 1 means "write", which == 0 means "read".*/
    if(which)
      vio->write_timeout_millis= timeout_millis;
    else
      vio->read_timeout_millis= timeout_millis;
}


#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_millis) != 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_millis) != 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);
}


/**
 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__ */