~drizzle-trunk/drizzle/development

/* 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 */

/*

  HFTODO this must be hidden if we don't want client capabilities in 

  embedded library

 */

#include <my_global.h>

#include <drizzle.h>

#include <drizzle_com.h>

#include <mysqld_error.h>

#include <my_sys.h>

#include <m_string.h>

#include <my_net.h>

#include <violite.h>

#include <signal.h>

#include <errno.h>

/*

  The following handles the differences when this is linked between the

  client and the server.

  This gives an error if a too big packet is found

  The server can change this with the -O switch, but because the client

  can't normally do this the client should have a bigger max_allowed_packet.

*/

#define DONT_USE_THR_ALARM

#include "thr_alarm.h"

#define update_statistics(A)

#define thd_increment_bytes_sent(N)

#define TEST_BLOCKING		8

#define MAX_PACKET_LENGTH (256L*256L*256L-1)

static bool net_write_buff(NET *net, const unsigned char *packet, uint32_t len);

/** Init with packet info. */

bool my_net_init(NET *net, Vio* vio)

{

  DBUG_ENTER("my_net_init");

  net->vio = vio;

  my_net_local_init(net);			/* Set some limits */

  if (!(net->buff=(uchar*) my_malloc((size_t) net->max_packet+

				     NET_HEADER_SIZE + COMP_HEADER_SIZE,

				     MYF(MY_WME))))

    DBUG_RETURN(1);

  net->buff_end=net->buff+net->max_packet;

  net->error=0; net->return_status=0;

  net->pkt_nr=net->compress_pkt_nr=0;

  net->write_pos=net->read_pos = net->buff;

  net->last_error[0]=0;

  net->compress=0; net->reading_or_writing=0;

  net->where_b = net->remain_in_buf=0;

  net->last_errno=0;

  net->unused= 0;

  if (vio != 0)					/* If real connection */

  {

    net->fd  = vio_fd(vio);			/* For perl DBI/DBD */

    vio_fastsend(vio);

  }

  DBUG_RETURN(0);

}

void net_end(NET *net)

{

  DBUG_ENTER("net_end");

  my_free(net->buff,MYF(MY_ALLOW_ZERO_PTR));

  net->buff=0;

  DBUG_VOID_RETURN;

}

/** Realloc the packet buffer. */

bool net_realloc(NET *net, size_t length)

{

  uchar *buff;

  size_t pkt_length;

  DBUG_ENTER("net_realloc");

  DBUG_PRINT("enter",("length: %lu", (ulong) length));

  if (length >= net->max_packet_size)

  {

    DBUG_PRINT("error", ("Packet too large. Max size: %lu",

                         net->max_packet_size));

    /* @todo: 1 and 2 codes are identical. */

    net->error= 1;

    net->last_errno= ER_NET_PACKET_TOO_LARGE;

    DBUG_RETURN(1);

  }

  pkt_length = (length+IO_SIZE-1) & ~(IO_SIZE-1); 

  /*

    We must allocate some extra bytes for the end 0 and to be able to

    read big compressed blocks

  */

  if (!(buff= (uchar*) my_realloc((char*) net->buff, pkt_length +

                                  NET_HEADER_SIZE + COMP_HEADER_SIZE,

                                  MYF(MY_WME))))

  {

    /* @todo: 1 and 2 codes are identical. */

    net->error= 1;

    net->last_errno= ER_OUT_OF_RESOURCES;

    /* In the server the error is reported by MY_WME flag. */

    DBUG_RETURN(1);

  }

  net->buff=net->write_pos=buff;

  net->buff_end=buff+(net->max_packet= (ulong) pkt_length);

  DBUG_RETURN(0);

}

/**

  Check if there is any data to be read from the socket.

  @param sd   socket descriptor

  @retval

    0  No data to read

  @retval

    1  Data or EOF to read

  @retval

    -1   Don't know if data is ready or not

*/

static int net_data_is_ready(my_socket sd)

{

#ifdef HAVE_POLL

  struct pollfd ufds;

  int res;

  ufds.fd= sd;

  ufds.events= POLLIN | POLLPRI;

  if (!(res= poll(&ufds, 1, 0)))

    return 0;

  if (res < 0 || !(ufds.revents & (POLLIN | POLLPRI)))

    return 0;

  return 1;

#else

  fd_set sfds;

  struct timeval tv;

  int res;

  /* Windows uses an _array_ of 64 fd's as default, so it's safe */

  if (sd >= FD_SETSIZE)

    return -1;

#define NET_DATA_IS_READY_CAN_RETURN_MINUS_ONE

  FD_ZERO(&sfds);

  FD_SET(sd, &sfds);

  tv.tv_sec= tv.tv_usec= 0;

  if ((res= select(sd+1, &sfds, NULL, NULL, &tv)) < 0)

    return 0;

  else

    return test(res ? FD_ISSET(sd, &sfds) : 0);

#endif /* HAVE_POLL */

}

/**

  Remove unwanted characters from connection

  and check if disconnected.

    Read from socket until there is nothing more to read. Discard

    what is read.

    If there is anything when to read 'net_clear' is called this

    normally indicates an error in the protocol.

    When connection is properly closed (for TCP it means with

    a FIN packet), then select() considers a socket "ready to read",

    in the sense that there's EOF to read, but read() returns 0.

  @param net			NET handler

  @param clear_buffer           if <> 0, then clear all data from comm buff

*/

void net_clear(NET *net, bool clear_buffer)

{

  size_t count;

  int32_t ready;

  DBUG_ENTER("net_clear");

  if (clear_buffer)

  {

    while ((ready= net_data_is_ready(net->vio->sd)) > 0)

    {

      /* The socket is ready */

      if ((long) (count= vio_read(net->vio, net->buff,

                                  (size_t) net->max_packet)) > 0)

      {

        DBUG_PRINT("info",("skipped %ld bytes from file: %s",

                           (long) count, vio_description(net->vio)));

      }

      else

      {

        DBUG_PRINT("info",("socket ready but only EOF to read - disconnected"));

        net->error= 2;

        break;

      }

    }

#ifdef NET_DATA_IS_READY_CAN_RETURN_MINUS_ONE

    /* 'net_data_is_ready' returned "don't know" */

    if (ready == -1)

    {

      /* Read unblocking to clear net */

      my_bool old_mode;

      if (!vio_blocking(net->vio, false, &old_mode))

      {

        while ((long) (count= vio_read(net->vio, net->buff,

                                       (size_t) net->max_packet)) > 0)

          DBUG_PRINT("info",("skipped %ld bytes from file: %s",

                             (long) count, vio_description(net->vio)));

        vio_blocking(net->vio, true, &old_mode);

      }

    }

#endif /* NET_DATA_IS_READY_CAN_RETURN_MINUS_ONE */

  }

  net->pkt_nr=net->compress_pkt_nr=0;		/* Ready for new command */

  net->write_pos=net->buff;

  DBUG_VOID_RETURN;

}

/** Flush write_buffer if not empty. */

bool net_flush(NET *net)

{

  my_bool error= 0;

  DBUG_ENTER("net_flush");

  if (net->buff != net->write_pos)

  {

    error=test(net_real_write(net, net->buff,

			      (size_t) (net->write_pos - net->buff)));

    net->write_pos=net->buff;

  }

  /* Sync packet number if using compression */

  if (net->compress)

    net->pkt_nr=net->compress_pkt_nr;

  DBUG_RETURN(error);

}

/*****************************************************************************

** Write something to server/client buffer

*****************************************************************************/

/**

  Write a logical packet with packet header.

  Format: Packet length (3 bytes), packet number(1 byte)

  When compression is used a 3 byte compression length is added

  @note

    If compression is used the original package is modified!

*/

bool

my_net_write(NET *net,const uchar *packet,size_t len)

{

  uchar buff[NET_HEADER_SIZE];

  if (unlikely(!net->vio)) /* nowhere to write */

    return 0;

  /*

    Big packets are handled by splitting them in packets of MAX_PACKET_LENGTH

    length. The last packet is always a packet that is < MAX_PACKET_LENGTH.

    (The last packet may even have a length of 0)

  */

  while (len >= MAX_PACKET_LENGTH)

  {

    const ulong z_size = MAX_PACKET_LENGTH;

    int3store(buff, z_size);

    buff[3]= (uchar) net->pkt_nr++;

    if (net_write_buff(net, buff, NET_HEADER_SIZE) ||

	net_write_buff(net, packet, z_size))

      return 1;

    packet += z_size;

    len-=     z_size;

  }

  /* Write last packet */

  int3store(buff,len);

  buff[3]= (uchar) net->pkt_nr++;

  if (net_write_buff(net, buff, NET_HEADER_SIZE))

    return 1;

#ifndef DEBUG_DATA_PACKETS

  DBUG_DUMP("packet_header", buff, NET_HEADER_SIZE);

#endif

  return test(net_write_buff(net,packet,len));

}

/**

  Send a command to the server.

    The reason for having both header and packet is so that libmysql

    can easy add a header to a special command (like prepared statements)

    without having to re-alloc the string.

    As the command is part of the first data packet, we have to do some data

    juggling to put the command in there, without having to create a new

    packet.

    This function will split big packets into sub-packets if needed.

    (Each sub packet can only be 2^24 bytes)

  @param net		NET handler

  @param command	Command in MySQL server (enum enum_server_command)

  @param header	Header to write after command

  @param head_len	Length of header

  @param packet	Query or parameter to query

  @param len		Length of packet

  @retval

    0	ok

  @retval

    1	error

*/

bool

net_write_command(NET *net,uchar command,

		  const uchar *header, size_t head_len,

		  const uchar *packet, size_t len)

{

  ulong length=len+1+head_len;			/* 1 extra byte for command */

  uchar buff[NET_HEADER_SIZE+1];

  uint header_size=NET_HEADER_SIZE+1;

  DBUG_ENTER("net_write_command");

  DBUG_PRINT("enter",("length: %lu", (ulong) len));

  buff[4]=command;				/* For first packet */

  if (length >= MAX_PACKET_LENGTH)

  {

    /* Take into account that we have the command in the first header */

    len= MAX_PACKET_LENGTH - 1 - head_len;

    do

    {

      int3store(buff, MAX_PACKET_LENGTH);

      buff[3]= (uchar) net->pkt_nr++;

      if (net_write_buff(net, buff, header_size) ||

	  net_write_buff(net, header, head_len) ||

	  net_write_buff(net, packet, len))

	DBUG_RETURN(1);

      packet+= len;

      length-= MAX_PACKET_LENGTH;

      len= MAX_PACKET_LENGTH;

      head_len= 0;

      header_size= NET_HEADER_SIZE;

    } while (length >= MAX_PACKET_LENGTH);

    len=length;					/* Data left to be written */

  }

  int3store(buff,length);

  buff[3]= (uchar) net->pkt_nr++;

  DBUG_RETURN(test(net_write_buff(net, buff, header_size) ||

                   (head_len && net_write_buff(net, header, head_len)) ||

                   net_write_buff(net, packet, len) || net_flush(net)));

}

/**

  Caching the data in a local buffer before sending it.

   Fill up net->buffer and send it to the client when full.

    If the rest of the to-be-sent-packet is bigger than buffer,

    send it in one big block (to avoid copying to internal buffer).

    If not, copy the rest of the data to the buffer and return without

    sending data.

  @param net		Network handler

  @param packet	Packet to send

  @param len		Length of packet

  @note

    The cached buffer can be sent as it is with 'net_flush()'.

    In this code we have to be careful to not send a packet longer than

    MAX_PACKET_LENGTH to net_real_write() if we are using the compressed

    protocol as we store the length of the compressed packet in 3 bytes.

  @retval

    0	ok

  @retval

    1

*/

static bool

net_write_buff(NET *net, const unsigned char *packet, uint32_t len)

{

  ulong left_length;

  if (net->compress && net->max_packet > MAX_PACKET_LENGTH)

    left_length= MAX_PACKET_LENGTH - (net->write_pos - net->buff);

  else

    left_length= (ulong) (net->buff_end - net->write_pos);

#ifdef DEBUG_DATA_PACKETS

  DBUG_DUMP("data", packet, len);

#endif

  if (len > left_length)

  {

    if (net->write_pos != net->buff)

    {

      /* Fill up already used packet and write it */

      memcpy((char*) net->write_pos,packet,left_length);

      if (net_real_write(net, net->buff, 

			 (size_t) (net->write_pos - net->buff) + left_length))

	return 1;

      net->write_pos= net->buff;

      packet+= left_length;

      len-= left_length;

    }

    if (net->compress)

    {

      /*

	We can't have bigger packets than 16M with compression

	Because the uncompressed length is stored in 3 bytes

      */

      left_length= MAX_PACKET_LENGTH;

      while (len > left_length)

      {

	if (net_real_write(net, packet, left_length))

	  return 1;

	packet+= left_length;

	len-= left_length;

      }

    }

    if (len > net->max_packet)

      return net_real_write(net, packet, len) ? 1 : 0;

    /* Send out rest of the blocks as full sized blocks */

  }

  memcpy((char*) net->write_pos,packet,len);

  net->write_pos+= len;

  return 0;

}

/**

  Read and write one packet using timeouts.

  If needed, the packet is compressed before sending.

  @todo

    - TODO is it needed to set this variable if we have no socket

*/

int

net_real_write(NET *net,const uchar *packet, size_t len)

{

  size_t length;

  const uchar *pos,*end;

  thr_alarm_t alarmed;

  uint retry_count=0;

  my_bool net_blocking = vio_is_blocking(net->vio);

  DBUG_ENTER("net_real_write");

  if (net->error == 2)

    DBUG_RETURN(-1);				/* socket can't be used */

  net->reading_or_writing=2;

  if (net->compress)

  {

    size_t complen;

    uchar *b;

    uint header_length=NET_HEADER_SIZE+COMP_HEADER_SIZE;

    if (!(b= (uchar*) my_malloc(len + NET_HEADER_SIZE +

                                COMP_HEADER_SIZE, MYF(MY_WME))))

    {

      net->error= 2;

      net->last_errno= ER_OUT_OF_RESOURCES;

      /* In the server, the error is reported by MY_WME flag. */

      net->reading_or_writing= 0;

      DBUG_RETURN(1);

    }

    memcpy(b+header_length,packet,len);

    if (my_compress(b+header_length, &len, &complen))

      complen=0;

    int3store(&b[NET_HEADER_SIZE],complen);

    int3store(b,len);

    b[3]=(uchar) (net->compress_pkt_nr++);

    len+= header_length;

    packet= b;

  }

#ifdef DEBUG_DATA_PACKETS

  DBUG_DUMP("data", packet, len);

#endif

  alarmed=0;

  /* Write timeout is set in my_net_set_write_timeout */

  pos= packet;

  end=pos+len;

  while (pos != end)

  {

    if ((long) (length= vio_write(net->vio,pos,(size_t) (end-pos))) <= 0)

    {

      my_bool interrupted = vio_should_retry(net->vio);

      if ((interrupted || length == 0) && !thr_alarm_in_use(&alarmed))

      {

        if (!thr_alarm(&alarmed, net->write_timeout, &alarm_buff))

        {                                       /* Always true for client */

	  my_bool old_mode;

	  while (vio_blocking(net->vio, true, &old_mode) < 0)

	  {

	    if (vio_should_retry(net->vio) && retry_count++ < net->retry_count)

	      continue;

#ifdef EXTRA_DEBUG

	    fprintf(stderr,

		    "%s: my_net_write: fcntl returned error %d, aborting thread\n",

		    my_progname,vio_errno(net->vio));

#endif /* EXTRA_DEBUG */

	    net->error= 2;                     /* Close socket */

            net->last_errno= ER_NET_PACKET_TOO_LARGE;

	    goto end;

	  }

	  retry_count=0;

	  continue;

	}

      }

      else

	if (thr_alarm_in_use(&alarmed) && !thr_got_alarm(&alarmed) &&

	    interrupted)

      {

	if (retry_count++ < net->retry_count)

	    continue;

#ifdef EXTRA_DEBUG

	  fprintf(stderr, "%s: write looped, aborting thread\n",

		  my_progname);

#endif /* EXTRA_DEBUG */

      }

      if (vio_errno(net->vio) == SOCKET_EINTR)

      {

	DBUG_PRINT("warning",("Interrupted write. Retrying..."));

	continue;

      }

      net->error= 2;				/* Close socket */

      net->last_errno= (interrupted ? ER_NET_WRITE_INTERRUPTED :

                               ER_NET_ERROR_ON_WRITE);

      break;

    }

    pos+=length;

    update_statistics(thd_increment_bytes_sent(length));

  }

 end:

  if (net->compress)

    my_free((char*) packet,MYF(0));

  if (thr_alarm_in_use(&alarmed))

  {

    my_bool old_mode;

    thr_end_alarm(&alarmed);

    vio_blocking(net->vio, net_blocking, &old_mode);

  }

  net->reading_or_writing=0;

  DBUG_RETURN(((int) (pos != end)));

}

/**

  Reads one packet to net->buff + net->where_b.

  Long packets are handled by my_net_read().

  This function reallocates the net->buff buffer if necessary.

  @return

    Returns length of packet.

*/

static ulong

my_real_read(NET *net, size_t *complen)

{

  uchar *pos;

  size_t length;

  uint i,retry_count=0;

  ulong len=packet_error;

  thr_alarm_t alarmed;

  my_bool net_blocking=vio_is_blocking(net->vio);

  uint32 remain= (net->compress ? NET_HEADER_SIZE+COMP_HEADER_SIZE :

		  NET_HEADER_SIZE);

  *complen = 0;

  net->reading_or_writing=1;

  thr_alarm_init(&alarmed);

  /* Read timeout is set in my_net_set_read_timeout */

    pos = net->buff + net->where_b;		/* net->packet -4 */

    for (i=0 ; i < 2 ; i++)

    {

      while (remain > 0)

      {

	/* First read is done with non blocking mode */

        if ((long) (length= vio_read(net->vio, pos, remain)) <= 0L)

        {

          my_bool interrupted = vio_should_retry(net->vio);

	  DBUG_PRINT("info",("vio_read returned %ld  errno: %d",

			     (long) length, vio_errno(net->vio)));

	  if (thr_alarm_in_use(&alarmed) && !thr_got_alarm(&alarmed) &&

	      interrupted)

	  {					/* Probably in MIT threads */

	    if (retry_count++ < net->retry_count)

	      continue;

#ifdef EXTRA_DEBUG

	    fprintf(stderr, "%s: read looped with error %d, aborting thread\n",

		    my_progname,vio_errno(net->vio));

#endif /* EXTRA_DEBUG */

	  }

	  if (vio_errno(net->vio) == SOCKET_EINTR)

	  {

	    DBUG_PRINT("warning",("Interrupted read. Retrying..."));

	    continue;

	  }

	  DBUG_PRINT("error",("Couldn't read packet: remain: %u  errno: %d  length: %ld",

			      remain, vio_errno(net->vio), (long) length));

	  len= packet_error;

	  net->error= 2;				/* Close socket */

          net->last_errno= (vio_was_interrupted(net->vio) ?

                                   ER_NET_READ_INTERRUPTED :

                                   ER_NET_READ_ERROR);

	  goto end;

	}

	remain -= (uint32) length;

	pos+= length;

	update_statistics(thd_increment_bytes_received(length));

      }

      if (i == 0)

      {					/* First parts is packet length */

	ulong helping;

        DBUG_DUMP("packet_header", net->buff+net->where_b,

                  NET_HEADER_SIZE);

	if (net->buff[net->where_b + 3] != (uchar) net->pkt_nr)

	{

	  if (net->buff[net->where_b] != (uchar) 255)

	  {

	    DBUG_PRINT("error",

		       ("Packets out of order (Found: %d, expected %u)",

			(int) net->buff[net->where_b + 3],

			net->pkt_nr));

#ifdef EXTRA_DEBUG

            fflush(stdout);

	    fprintf(stderr,"Error: Packets out of order (Found: %d, expected %d)\n",

		    (int) net->buff[net->where_b + 3],

		    (uint) (uchar) net->pkt_nr);

            fflush(stderr);

            DBUG_ASSERT(0);

#endif

	  }

	  len= packet_error;

          /* Not a NET error on the client. XXX: why? */

	  goto end;

	}

	net->compress_pkt_nr= ++net->pkt_nr;

	if (net->compress)

	{

	  /*

	    If the packet is compressed then complen > 0 and contains the

	    number of bytes in the uncompressed packet

	  */

	  *complen=uint3korr(&(net->buff[net->where_b + NET_HEADER_SIZE]));

	}

	len=uint3korr(net->buff+net->where_b);

	if (!len)				/* End of big multi-packet */

	  goto end;

	helping = max(len,*complen) + net->where_b;

	/* The necessary size of net->buff */

	if (helping >= net->max_packet)

	{

	  if (net_realloc(net,helping))

	  {

	    len= packet_error;          /* Return error and close connection */

	    goto end;

	  }

	}

	pos=net->buff + net->where_b;

	remain = (uint32) len;

      }

    }

end:

  if (thr_alarm_in_use(&alarmed))

  {

    my_bool old_mode;

    thr_end_alarm(&alarmed);

    vio_blocking(net->vio, net_blocking, &old_mode);

  }

  net->reading_or_writing=0;

#ifdef DEBUG_DATA_PACKETS

  if (len != packet_error)

    DBUG_DUMP("data", net->buff+net->where_b, len);

#endif

  return(len);

}

/**

  Read a packet from the client/server and return it without the internal

  package header.

  If the packet is the first packet of a multi-packet packet

  (which is indicated by the length of the packet = 0xffffff) then

  all sub packets are read and concatenated.

  If the packet was compressed, its uncompressed and the length of the

  uncompressed packet is returned.

  @return

  The function returns the length of the found packet or packet_error.

  net->read_pos points to the read data.

*/

uint32_t

my_net_read(NET *net)

{

  size_t len, complen;

  if (!net->compress)

  {

    len = my_real_read(net,&complen);

    if (len == MAX_PACKET_LENGTH)

    {

      /* First packet of a multi-packet.  Concatenate the packets */

      ulong save_pos = net->where_b;

      size_t total_length= 0;

      do

      {

	net->where_b += len;

	total_length += len;

	len = my_real_read(net,&complen);

      } while (len == MAX_PACKET_LENGTH);

      if (len != packet_error)

	len+= total_length;

      net->where_b = save_pos;

    }

    net->read_pos = net->buff + net->where_b;

    if (len != packet_error)

      net->read_pos[len]=0;		/* Safeguard for mysql_use_result */

    return len;

  }

  else

  {

    /* We are using the compressed protocol */

    ulong buf_length;

    ulong start_of_packet;

    ulong first_packet_offset;

    uint read_length, multi_byte_packet=0;

    if (net->remain_in_buf)

    {

      buf_length= net->buf_length;		/* Data left in old packet */

      first_packet_offset= start_of_packet= (net->buf_length -

					     net->remain_in_buf);

      /* Restore the character that was overwritten by the end 0 */

      net->buff[start_of_packet]= net->save_char;

    }

    else

    {

      /* reuse buffer, as there is nothing in it that we need */

      buf_length= start_of_packet= first_packet_offset= 0;

    }

    for (;;)

    {

      ulong packet_len;

      if (buf_length - start_of_packet >= NET_HEADER_SIZE)

      {

	read_length = uint3korr(net->buff+start_of_packet);

	if (!read_length)

	{ 

	  /* End of multi-byte packet */

	  start_of_packet += NET_HEADER_SIZE;

	  break;

	}

	if (read_length + NET_HEADER_SIZE <= buf_length - start_of_packet)

	{

	  if (multi_byte_packet)