1  /*
       2   * Check decoding of fchownat 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  #include <fcntl.h>
      14  
      15  #if defined AT_FDCWD && defined AT_SYMLINK_NOFOLLOW
      16  
      17  # include <stdio.h>
      18  # include <unistd.h>
      19  
      20  # include "secontext.h"
      21  
      22  int
      23  main(void)
      24  {
      25  	/*
      26  	 * Make sure the current workdir of the tracee
      27  	 * is different from the current workdir of the tracer.
      28  	 */
      29  	create_and_enter_subdir("fchownat_subdir");
      30  
      31  	char *my_secontext = SECONTEXT_PID_MY();
      32  	uid_t uid = geteuid();
      33  	uid_t gid = getegid();
      34  
      35  	static const char sample[] = "fchownat_sample";
      36  	int fd = open(sample, O_RDONLY | O_CREAT, 0400);
      37  	if (fd == -1)
      38  		perror_msg_and_fail("open");
      39  	close(fd);
      40  
      41  	char *sample_secontext = SECONTEXT_FILE(sample);
      42  
      43  	/*
      44  	 * Tests with AT_FDCWD.
      45  	 */
      46  
      47  	long rc = syscall(__NR_fchownat, AT_FDCWD, sample, uid, gid, 0);
      48  	printf("%s%s(AT_FDCWD, \"%s\"%s, %d, %d, 0) = %s\n",
      49  	       my_secontext, "fchownat",
      50  	       sample, sample_secontext,
      51  	       uid, gid, sprintrc(rc));
      52  
      53  	if (unlink(sample))
      54  		perror_msg_and_fail("unlink");
      55  
      56  	rc = syscall(__NR_fchownat, AT_FDCWD,
      57  		     sample, -1, -1L, AT_SYMLINK_NOFOLLOW);
      58  	printf("%s%s(AT_FDCWD, \"%s\", -1, -1, AT_SYMLINK_NOFOLLOW) = %s\n",
      59  	       my_secontext, "fchownat",
      60  	       sample, sprintrc(rc));
      61  
      62  	/*
      63  	 * Tests with dirfd.
      64  	 */
      65  
      66  	int cwd_fd = get_dir_fd(".");
      67  	char *cwd = get_fd_path(cwd_fd);
      68  	char *cwd_secontext = SECONTEXT_FILE(".");
      69  	char *sample_realpath = xasprintf("%s/%s", cwd, sample);
      70  
      71  	/* no file */
      72  	rc = syscall(__NR_fchownat, cwd_fd, sample, uid, gid, 0);
      73  	printf("%s%s(%d%s, \"%s\", %d, %d, 0) = %s\n",
      74  	       my_secontext, "fchownat",
      75  	       cwd_fd, cwd_secontext,
      76  	       sample,
      77  	       uid, gid,
      78  	       sprintrc(rc));
      79  
      80  	fd = open(sample, O_RDONLY | O_CREAT, 0400);
      81  	if (fd == -1)
      82  		perror_msg_and_fail("open");
      83  	close(fd);
      84  
      85  	rc = syscall(__NR_fchownat, cwd_fd, sample, uid, gid, 0);
      86  	printf("%s%s(%d%s, \"%s\"%s, %d, %d, 0) = %s\n",
      87  	       my_secontext, "fchownat",
      88  	       cwd_fd, cwd_secontext,
      89  	       sample, sample_secontext,
      90  	       uid, gid,
      91  	       sprintrc(rc));
      92  
      93  	/* cwd_fd ignored when path is absolute */
      94  	if (chdir("../.."))
      95  		perror_msg_and_fail("chdir");
      96  
      97  	rc = syscall(__NR_fchownat, cwd_fd, sample_realpath, uid, gid, 0);
      98  	printf("%s%s(%d%s, \"%s\"%s, %d, %d, 0) = %s\n",
      99  	       my_secontext, "fchownat",
     100  	       cwd_fd, cwd_secontext,
     101  	       sample_realpath, sample_secontext,
     102  	       uid, gid,
     103  	       sprintrc(rc));
     104  
     105  	if (fchdir(cwd_fd))
     106  		perror_msg_and_fail("fchdir");
     107  
     108  	if (unlink(sample))
     109  		perror_msg_and_fail("unlink");
     110  
     111  	leave_and_remove_subdir();
     112  
     113  	puts("+++ exited with 0 +++");
     114  	return 0;
     115  }
     116  
     117  #else
     118  
     119  SKIP_MAIN_UNDEFINED("AT_FDCWD && AT_SYMLINK_NOFOLLOW")
     120  
     121  #endif