Line data    Source code

       1             : /*
       2             :  * Unix SMB/CIFS implementation.
       3             :  * Utility functions to transfer files.
       4             :  *
       5             :  * Copyright (C) Jeremy Allison 2001-2002
       6             :  * Copyright (C) Michael Adam 2008
       7             :  *
       8             :  * This program is free software; you can redistribute it and/or modify
       9             :  * it under the terms of the GNU General Public License as published by
      10             :  * the Free Software Foundation; either version 3 of the License, or
      11             :  * (at your option) any later version.
      12             :  *
      13             :  * This program is distributed in the hope that it will be useful,
      14             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      15             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      16             :  * GNU General Public License for more details.
      17             :  *
      18             :  * You should have received a copy of the GNU General Public License
      19             :  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
      20             :  */
      21             : 
      22             : 
      23             : #include <includes.h>
      24             : #include "transfer_file.h"
      25             : #include "lib/util/sys_rw.h"
      26             : 
      27             : /****************************************************************************
      28             :  Transfer some data between two fd's.
      29             : ****************************************************************************/
      30             : 
      31             : #ifndef TRANSFER_BUF_SIZE
      32             : #define TRANSFER_BUF_SIZE 65536
      33             : #endif
      34             : 
      35             : 
      36          26 : ssize_t transfer_file_internal(void *in_file,
      37             :                                void *out_file,
      38             :                                size_t n,
      39             :                                ssize_t (*pread_fn)(void *, void *, size_t, off_t),
      40             :                                ssize_t (*pwrite_fn)(void *, const void *, size_t, off_t))
      41             : {
      42           2 :         char *buf;
      43          26 :         size_t total = 0;
      44           2 :         ssize_t read_ret;
      45           2 :         ssize_t write_ret;
      46           2 :         size_t num_to_read_thistime;
      47          26 :         size_t num_written = 0;
      48          26 :         off_t offset = 0;
      49             : 
      50          26 :         if (n == 0) {
      51           0 :                 return 0;
      52             :         }
      53             : 
      54          26 :         if ((buf = SMB_MALLOC_ARRAY(char, TRANSFER_BUF_SIZE)) == NULL) {
      55           0 :                 return -1;
      56             :         }
      57             : 
      58           2 :         do {
      59          26 :                 num_to_read_thistime = MIN((n - total), TRANSFER_BUF_SIZE);
      60             : 
      61          26 :                 read_ret = (*pread_fn)(in_file, buf, num_to_read_thistime, offset);
      62          26 :                 if (read_ret == -1) {
      63           0 :                         DEBUG(0,("transfer_file_internal: read failure. "
      64             :                                  "Error = %s\n", strerror(errno) ));
      65           0 :                         SAFE_FREE(buf);
      66           0 :                         return -1;
      67             :                 }
      68          26 :                 if (read_ret == 0) {
      69           0 :                         break;
      70             :                 }
      71             : 
      72          24 :                 num_written = 0;
      73             : 
      74          52 :                 while (num_written < read_ret) {
      75          28 :                         write_ret = (*pwrite_fn)(out_file, buf + num_written,
      76             :                                                 read_ret - num_written,
      77          26 :                                                 offset + num_written);
      78             : 
      79          26 :                         if (write_ret == -1) {
      80           0 :                                 DEBUG(0,("transfer_file_internal: "
      81             :                                          "write failure. Error = %s\n",
      82             :                                          strerror(errno) ));
      83           0 :                                 SAFE_FREE(buf);
      84           0 :                                 return -1;
      85             :                         }
      86          26 :                         if (write_ret == 0) {
      87           0 :                                 return (ssize_t)total;
      88             :                         }
      89             : 
      90          26 :                         num_written += (size_t)write_ret;
      91             :                 }
      92             : 
      93          26 :                 total += (size_t)read_ret;
      94          26 :                 offset += (off_t)read_ret;
      95          26 :         } while (total < n);
      96             : 
      97          26 :         SAFE_FREE(buf);
      98          26 :         return (ssize_t)total;
      99             : }
     100             : 
     101           0 : static ssize_t sys_pread_fn(void *file, void *buf, size_t len, off_t offset)
     102             : {
     103           0 :         int *fd = (int *)file;
     104             : 
     105           0 :         return sys_pread(*fd, buf, len, offset);
     106             : }
     107             : 
     108           0 : static ssize_t sys_pwrite_fn(void *file, const void *buf, size_t len, off_t offset)
     109             : {
     110           0 :         int *fd = (int *)file;
     111             : 
     112           0 :         return sys_pwrite(*fd, buf, len, offset);
     113             : }
     114             : 
     115           0 : off_t transfer_file(int infd, int outfd, off_t n)
     116             : {
     117           0 :         return (off_t)transfer_file_internal(&infd, &outfd, (size_t)n,
     118             :                                                  sys_pread_fn, sys_pwrite_fn);
     119             : }