source: vendor/3.5.11/source4/libcli/clireadwrite.c

/* 
   Unix SMB/CIFS implementation.
   client file read/write routines
   Copyright (C) Andrew Tridgell 1994-1998
   Copyright (C) James Myers 2003
   
   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; either version 3 of the License, or
   (at your option) any later version.
   
   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, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "libcli/raw/libcliraw.h"
#include "libcli/raw/raw_proto.h"
#include "libcli/libcli.h"

/****************************************************************************
  Read size bytes at offset offset using SMBreadX.
****************************************************************************/
ssize_t smbcli_read(struct smbcli_tree *tree, int fnum, void *_buf, off_t offset, 
                 size_t size)
{
        uint8_t *buf = (uint8_t *)_buf;
        union smb_read parms;
        int readsize;
        ssize_t total = 0;
        
        if (size == 0) {
                return 0;
        }

        parms.readx.level = RAW_READ_READX;
        parms.readx.in.file.fnum = fnum;

        /*
         * Set readsize to the maximum size we can handle in one readX,
         * rounded down to a multiple of 1024.
         */
        readsize = (tree->session->transport->negotiate.max_xmit - (MIN_SMB_SIZE+32));
        if (readsize > 0xFFFF) readsize = 0xFFFF;

        while (total < size) {
                NTSTATUS status;

                readsize = MIN(readsize, size-total);

                parms.readx.in.offset    = offset;
                parms.readx.in.mincnt    = readsize;
                parms.readx.in.maxcnt    = readsize;
                parms.readx.in.remaining = size - total;
                parms.readx.in.read_for_execute = false;
                parms.readx.out.data     = buf + total;
                
                status = smb_raw_read(tree, &parms);
                
                if (!NT_STATUS_IS_OK(status)) {
                        return -1;
                }

                total += parms.readx.out.nread;
                offset += parms.readx.out.nread;

                /* If the server returned less than we asked for we're at EOF */
                if (parms.readx.out.nread < readsize)
                        break;
        }

        return total;
}


/****************************************************************************
  write to a file
  write_mode: 0x0001 disallow write cacheing
              0x0002 return bytes remaining
              0x0004 use raw named pipe protocol
              0x0008 start of message mode named pipe protocol
****************************************************************************/
ssize_t smbcli_write(struct smbcli_tree *tree,
                     int fnum, uint16_t write_mode,
                     const void *_buf, off_t offset, size_t size)
{
        const uint8_t *buf = (const uint8_t *)_buf;
        union smb_write parms;
        int block = (tree->session->transport->negotiate.max_xmit - (MIN_SMB_SIZE+32));
        ssize_t total = 0;

        if (size == 0) {
                return 0;
        }

        if (block > 0xFFFF) block = 0xFFFF;


        parms.writex.level = RAW_WRITE_WRITEX;
        parms.writex.in.file.fnum = fnum;
        parms.writex.in.wmode = write_mode;
        parms.writex.in.remaining = 0;
        
        while (total < size) {
                NTSTATUS status;

                block = MIN(block, size - total);

                parms.writex.in.offset = offset;
                parms.writex.in.count = block;
                parms.writex.in.data = buf;

                status = smb_raw_write(tree, &parms);

                if (!NT_STATUS_IS_OK(status)) {
                        return -1;
                }

                offset += parms.writex.out.nwritten;
                total += parms.writex.out.nwritten;
                buf += parms.writex.out.nwritten;
        }

        return total;
}

/****************************************************************************
  write to a file using a SMBwrite and not bypassing 0 byte writes
****************************************************************************/
ssize_t smbcli_smbwrite(struct smbcli_tree *tree,
                     int fnum, const void *_buf, off_t offset, size_t size1)
{
        const uint8_t *buf = (const uint8_t *)_buf;
        union smb_write parms;
        ssize_t total = 0;

        parms.write.level = RAW_WRITE_WRITE;
        parms.write.in.remaining = 0;
        
        do {
                size_t size = MIN(size1, tree->session->transport->negotiate.max_xmit - 48);
                if (size > 0xFFFF) size = 0xFFFF;
                
                parms.write.in.file.fnum = fnum;
                parms.write.in.offset = offset;
                parms.write.in.count = size;
                parms.write.in.data = buf + total;

                if (NT_STATUS_IS_ERR(smb_raw_write(tree, &parms)))
                        return -1;

                size = parms.write.out.nwritten;
                if (size == 0)
                        break;

                size1 -= size;
                total += size;
                offset += size;
        } while (size1);

        return total;
}