Line data    Source code

       1             : /*
       2             :  * Unix SMB/CIFS implementation.
       3             :  * Samba utility functions
       4             :  * Copyright (C) Volker Lendecke 2014
       5             :  *
       6             :  * This program is free software; you can redistribute it and/or modify
       7             :  * it under the terms of the GNU General Public License as published by
       8             :  * the Free Software Foundation; either version 3 of the License, or
       9             :  * (at your option) any later version.
      10             :  *
      11             :  * This program is distributed in the hope that it will be useful,
      12             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14             :  * GNU General Public License for more details.
      15             :  *
      16             :  * You should have received a copy of the GNU General Public License
      17             :  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
      18             :  */
      19             : 
      20             : #include "replace.h"
      21             : #include "system/filesys.h"
      22             : #include "close_low_fd.h"
      23             : 
      24             : #ifdef HAVE_VALGRIND_VALGRIND_H
      25             : #include <valgrind/valgrind.h>
      26             : #elif defined(HAVE_VALGRIND_H)
      27             : #include <valgrind.h>
      28             : #else
      29             : #define RUNNING_ON_VALGRIND 0
      30             : #endif
      31             : 
      32         290 : _PUBLIC_ int close_low_fd(int fd)
      33             : {
      34           0 :         int ret, dev_null;
      35             : 
      36           0 :         if (RUNNING_ON_VALGRIND) {
      37             :                 return 0;
      38             :         }
      39             : 
      40         290 :         dev_null = open("/dev/null", O_RDWR, 0);
      41             : 
      42         290 :         if ((dev_null == -1) && (errno == ENFILE)) {
      43             :                 /*
      44             :                  * Try to free up an fd
      45             :                  */
      46           0 :                 ret = close(fd);
      47           0 :                 if (ret != 0) {
      48           0 :                         return errno;
      49             :                 }
      50             :         }
      51             : 
      52         290 :         dev_null = open("/dev/null", O_RDWR, 0);
      53         290 :         if (dev_null == -1) {
      54           0 :                 dev_null = open("/dev/null", O_WRONLY, 0);
      55             :         }
      56         290 :         if (dev_null == -1) {
      57           0 :                 return errno;
      58             :         }
      59             : 
      60         290 :         if (dev_null == fd) {
      61             :                 /*
      62             :                  * This can happen in the ENFILE case above
      63             :                  */
      64           0 :                 return 0;
      65             :         }
      66             : 
      67         290 :         ret = dup2(dev_null, fd);
      68         290 :         if (ret == -1) {
      69           0 :                 int err = errno;
      70           0 :                 close(dev_null);
      71           0 :                 return err;
      72             :         }
      73         290 :         close(dev_null);
      74         290 :         return 0;
      75             : }