1  /* Test of create_pipe_bidi/wait_subprocess.
       2     Copyright (C) 2009-2021 Free Software Foundation, Inc.
       3  
       4     This program is free software; you can redistribute it and/or modify
       5     it under the terms of the GNU General Public License as published by
       6     the Free Software Foundation; either version 3, or (at your option)
       7     any later version.
       8  
       9     This program is distributed in the hope that it will be useful,
      10     but WITHOUT ANY WARRANTY; without even the implied warranty of
      11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      12     GNU General Public License for more details.
      13  
      14     You should have received a copy of the GNU General Public License
      15     along with this program; if not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  #include <config.h>
      18  
      19  #include "spawn-pipe.h"
      20  #include "wait-process.h"
      21  
      22  #include <stdbool.h>
      23  #include <stdio.h>
      24  #include <stdlib.h>
      25  #include <string.h>
      26  #include <unistd.h>
      27  
      28  /* Depending on arguments, this test intentionally closes stderr or
      29     starts life with stderr closed.  So, we arrange to have fd 10
      30     (outside the range of interesting fd's during the test) set up to
      31     duplicate the original stderr.  */
      32  
      33  #define BACKUP_STDERR_FILENO 10
      34  #define ASSERT_STREAM myerr
      35  #include "macros.h"
      36  
      37  static FILE *myerr;
      38  
      39  /* Create a bi-directional pipe to a test child, and validate that the
      40     child program returns the expected output.
      41     PROG is the program to run in the child process.
      42     STDERR_CLOSED is true if we have already closed fd 2.  */
      43  static void
      44  test_pipe (const char *prog, bool stderr_closed)
      45  {
      46    int fd[2];
      47    const char *argv[3];
      48    pid_t pid;
      49    char buffer[2] = { 'a', 't' };
      50  
      51    /* Set up child.  */
      52    argv[0] = prog;
      53    argv[1] = (stderr_closed ? "1" : "0");
      54    argv[2] = NULL;
      55    pid = create_pipe_bidi (prog, prog, argv, NULL, false, true, true, fd);
      56    ASSERT (0 <= pid);
      57    ASSERT (STDERR_FILENO < fd[0]);
      58    ASSERT (STDERR_FILENO < fd[1]);
      59  
      60    /* Push child's input.  */
      61    ASSERT (write (fd[1], buffer, 1) == 1);
      62    ASSERT (close (fd[1]) == 0);
      63  
      64    /* Get child's output.  */
      65    ASSERT (read (fd[0], buffer, 2) == 1);
      66  
      67    /* Wait for child.  */
      68    ASSERT (wait_subprocess (pid, prog, true, false, true, true, NULL) == 0);
      69    ASSERT (close (fd[0]) == 0);
      70  
      71    /* Check the result.  */
      72    ASSERT (buffer[0] == 'b');
      73    ASSERT (buffer[1] == 't');
      74  }
      75  
      76  int
      77  main (int argc, char *argv[])
      78  {
      79    int test;
      80    int fd;
      81  
      82    if (argc != 3)
      83      {
      84        fprintf (stderr, "%s: need 2 arguments\n", argv[0]);
      85        return 2;
      86      }
      87    /* We might close fd 2 later, so save it in fd 10.  */
      88    if (dup2 (STDERR_FILENO, BACKUP_STDERR_FILENO) != BACKUP_STDERR_FILENO
      89        || (myerr = fdopen (BACKUP_STDERR_FILENO, "w")) == NULL)
      90      return 2;
      91  
      92    /* Selectively close various standard fds, to verify the child process is
      93       not impacted by this.  */
      94    test = atoi (argv[2]);
      95    switch (test)
      96      {
      97      case 0:
      98        break;
      99      case 1:
     100        close (0);
     101        break;
     102      case 2:
     103        close (1);
     104        break;
     105      case 3:
     106        close (0);
     107        close (1);
     108        break;
     109      case 4:
     110        close (2);
     111        break;
     112      case 5:
     113        close (0);
     114        close (2);
     115        break;
     116      case 6:
     117        close (1);
     118        close (2);
     119        break;
     120      case 7:
     121        close (0);
     122        close (1);
     123        close (2);
     124        break;
     125      default:
     126        ASSERT (false);
     127      }
     128  
     129    /* Plug any file descriptor leaks inherited from outside world before
     130       starting, so that child has a clean slate (at least for the fds that we
     131       might be manipulating).  */
     132    for (fd = 3; fd < 7; fd++)
     133      close (fd);
     134  
     135    test_pipe (argv[1], test >= 4);
     136  
     137    return 0;
     138  }