1  /*
       2   * Check decoding of fchmodat syscall.
       3   *
       4   * Copyright (c) 2016-2018 Dmitry V. Levin <ldv@strace.io>
       5   * Copyright (c) 2016-2021 The strace developers.
       6   * All rights reserved.
       7   *
       8   * SPDX-License-Identifier: GPL-2.0-or-later
       9   */
      10  
      11  #include "tests.h"
      12  #include "scno.h"
      13  
      14  #include <fcntl.h>
      15  #include <stdio.h>
      16  #include <unistd.h>
      17  
      18  #include "secontext.h"
      19  
      20  int
      21  main(void)
      22  {
      23  	/*
      24  	 * Make sure the current workdir of the tracee
      25  	 * is different from the current workdir of the tracer.
      26  	 */
      27  	create_and_enter_subdir("fchmodat_subdir");
      28  
      29  	char *my_secontext = SECONTEXT_PID_MY();
      30  
      31  	static const char sample[] = "fchmodat_sample_file";
      32  	if (open(sample, O_RDONLY | O_CREAT, 0400) < 0)
      33  		perror_msg_and_fail("open");
      34  
      35  	char *sample_secontext = SECONTEXT_FILE(sample);
      36  
      37  	/*
      38  	 * Tests with AT_FDCWD.
      39  	 */
      40  
      41  	long rc = syscall(__NR_fchmodat, -100, sample, 0600);
      42  	printf("%s%s(AT_FDCWD, \"%s\"%s, 0600) = %s\n",
      43  	       my_secontext, "fchmodat",
      44  	       sample, sample_secontext,
      45  	       sprintrc(rc));
      46  
      47  	if (unlink(sample))
      48  		perror_msg_and_fail("unlink");
      49  
      50  	rc = syscall(__NR_fchmodat, -100, sample, 051);
      51  	printf("%s%s(AT_FDCWD, \"%s\", 051) = %s\n",
      52  	       my_secontext, "fchmodat",
      53  	       sample, sprintrc(rc));
      54  
      55  	rc = syscall(__NR_fchmodat, -100, sample, 004);
      56  	printf("%s%s(AT_FDCWD, \"%s\", 004) = %s\n",
      57  	       my_secontext, "fchmodat",
      58  	       sample, sprintrc(rc));
      59  
      60  	/*
      61  	 * Tests with dirfd.
      62  	 */
      63  
      64  	int cwd_fd = get_dir_fd(".");
      65  	char *cwd = get_fd_path(cwd_fd);
      66  	char *cwd_secontext = SECONTEXT_FILE(".");
      67  	char *sample_realpath = xasprintf("%s/%s", cwd, sample);
      68  
      69  	/* no file */
      70  	rc = syscall(__NR_fchmodat, cwd_fd, sample, 0400);
      71  	printf("%s%s(%d%s, \"%s\", 0400) = %s\n",
      72  	       my_secontext, "fchmodat",
      73  	       cwd_fd, cwd_secontext,
      74  	       sample,
      75  	       sprintrc(rc));
      76  
      77  	if (open(sample, O_RDONLY | O_CREAT, 0400) < 0)
      78  		perror_msg_and_fail("open");
      79  
      80  	rc = syscall(__NR_fchmodat, cwd_fd, sample, 0400);
      81  	printf("%s%s(%d%s, \"%s\"%s, 0400) = %s\n",
      82  	       my_secontext, "fchmodat",
      83  	       cwd_fd, cwd_secontext,
      84  	       sample, sample_secontext,
      85  	       sprintrc(rc));
      86  
      87  	/* cwd_fd ignored when path is absolute */
      88  	if (chdir("../.."))
      89  		perror_msg_and_fail("chdir");
      90  
      91  	rc = syscall(__NR_fchmodat, cwd_fd, sample_realpath, 0400);
      92  	printf("%s%s(%d%s, \"%s\"%s, 0400) = %s\n",
      93  	       my_secontext, "fchmodat",
      94  	       cwd_fd, cwd_secontext,
      95  	       sample_realpath, sample_secontext,
      96  	       sprintrc(rc));
      97  
      98  	if (fchdir(cwd_fd))
      99  		perror_msg_and_fail("fchdir");
     100  
     101  	if (unlink(sample))
     102  		perror_msg_and_fail("unlink");
     103  
     104  	leave_and_remove_subdir();
     105  
     106  	puts("+++ exited with 0 +++");
     107  	return 0;
     108  }