posix/tst-spawn-chdir.c

   1 /* Test the posix_spawn_file_actions_addchdir_np function.
   2    Copyright (C) 2018-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <array_length.h>
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <spawn.h>
  23 #include <stdbool.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <support/check.h>
  27 #include <support/support.h>
  28 #include <support/temp_file.h>
  29 #include <support/test-driver.h>
  30 #include <support/xstdio.h>
  31 #include <support/xunistd.h>
  32 #include <sys/wait.h>
  33 #include <unistd.h>
  34 #include <tst-spawn.h>
  35
  36 /* Reads the file at PATH, which must consist of exactly one line.
  37    Removes the line terminator at the end of the file.  */
  38 static char *
  39 read_one_line (const char *path)
  40 {
  41   FILE *fp = xfopen (path, "r");
  42   char *buffer = NULL;
  43   size_t length = 0;
  44   ssize_t ret = getline (&buffer, &length, fp);
  45   if (ferror (fp))
  46     FAIL_EXIT1 ("getline: %m");
  47   if (ret < 1)
  48     FAIL_EXIT1 ("getline returned %zd", ret);
  49   if (fgetc (fp) != EOF)
  50     FAIL_EXIT1 ("trailing bytes in %s", path);
  51   if (ferror (fp))
  52     FAIL_EXIT1 ("fgetc: %m");
  53   xfclose (fp);
  54   if (buffer[ret - 1] != '\n')
  55     FAIL_EXIT1 ("missing line terminator in %s", path);
  56   buffer[ret - 1] = 0;
  57   return buffer;
  58 }
  59
  60 /* Return the path to the "pwd" program.  */
  61 const char *
  62 get_pwd_program (void)
  63 {
  64   const char *const paths[] = { "/bin/pwd", "/usr/bin/pwd" };
  65   for (size_t i = 0; i < array_length (paths); ++i)
  66     if (access (paths[i], X_OK) == 0)
  67       return paths[i];
  68   FAIL_EXIT1 ("cannot find pwd program");
  69 }
  70
  71 /* Adds chdir operations to ACTIONS, using PATH.  If DO_FCHDIR, use
  72    the open function and TMPFD to emulate chdir using fchdir.  */
  73 static void
  74 add_chdir (posix_spawn_file_actions_t *actions, const char *path,
  75            bool do_fchdir, int tmpfd)
  76 {
  77   if (do_fchdir)
  78     {
  79       TEST_COMPARE (posix_spawn_file_actions_addopen
  80                     (actions, tmpfd, path, O_DIRECTORY | O_RDONLY, 0), 0);
  81       TEST_COMPARE (posix_spawn_file_actions_addfchdir_np
  82                     (actions, tmpfd), 0);
  83       TEST_COMPARE (posix_spawn_file_actions_addclose (actions, tmpfd), 0);
  84     }
  85   else
  86     TEST_COMPARE (posix_spawn_file_actions_addchdir_np (actions, path), 0);
  87 }
  88
  89 static int
  90 do_test (void)
  91 {
  92   /* Directory for temporary file data.  Each subtest uses a numeric
  93      subdirectory.  */
  94   char *directory = support_create_temp_directory ("tst-spawn-chdir-");
  95   {
  96     /* Avoid symbolic links, to get more consistent behavior from the
  97        pwd command.  */
  98     char *tmp = realpath (directory, NULL);
  99     if (tmp == NULL)
 100       FAIL_EXIT1 ("realpath: %m");
 101     free (directory);
 102     directory = tmp;
 103   }
 104
 105   char *original_cwd = get_current_dir_name ();
 106   if (original_cwd == NULL)
 107     FAIL_EXIT1 ("get_current_dir_name: %m");
 108
 109   int iteration = 0;
 110   for (int do_spawnp = 0; do_spawnp < 2; ++do_spawnp)
 111     for (int do_overwrite = 0; do_overwrite < 2; ++do_overwrite)
 112       for (int do_fchdir = 0; do_fchdir < 2; ++do_fchdir)
 113         {
 114           /* This subtest does not make sense for fchdir.  */
 115           if (do_overwrite && do_fchdir)
 116             continue;
 117
 118           ++iteration;
 119           if (test_verbose > 0)
 120             printf ("info: iteration=%d do_spawnp=%d do_overwrite=%d"
 121                     " do_fchdir=%d\n",
 122                     iteration, do_spawnp, do_overwrite, do_fchdir);
 123
 124           /* The "pwd" program runs in this directory.  */
 125           char *iteration_directory = xasprintf ("%s/%d", directory, iteration);
 126           add_temp_file (iteration_directory);
 127           xmkdir (iteration_directory, 0777);
 128
 129           /* This file receives output from "pwd".  */
 130           char *output_file_path
 131             = xasprintf ("%s/output-file", iteration_directory);
 132           add_temp_file (output_file_path);
 133
 134           /* This subdirectory is used for chdir ordering checks.  */
 135           char *subdir_path = xasprintf ("%s/subdir", iteration_directory);
 136           add_temp_file (subdir_path);
 137           xmkdir (subdir_path, 0777);
 138
 139           /* Also used for checking the order of actions.  */
 140           char *probe_file_path
 141             = xasprintf ("%s/subdir/probe-file", iteration_directory);
 142           add_temp_file (probe_file_path);
 143           TEST_COMPARE (access (probe_file_path, F_OK), -1);
 144           TEST_COMPARE (errno, ENOENT);
 145
 146           /* This symbolic link is used in a relative path with
 147              posix_spawn.  */
 148           char *pwd_symlink_path
 149             = xasprintf ("%s/subdir/pwd-symlink", iteration_directory);
 150           xsymlink (get_pwd_program (), pwd_symlink_path);
 151           add_temp_file (pwd_symlink_path);
 152
 153           posix_spawn_file_actions_t actions;
 154           TEST_COMPARE (posix_spawn_file_actions_init (&actions), 0);
 155           add_chdir (&actions, subdir_path, do_fchdir, 4);
 156           TEST_COMPARE (posix_spawn_file_actions_addopen
 157                         (&actions, 3, /* Arbitrary unused descriptor.  */
 158                          "probe-file",
 159                          O_WRONLY | O_CREAT | O_EXCL, 0777), 0);
 160           TEST_COMPARE (posix_spawn_file_actions_addclose (&actions, 3), 0);
 161           /* Run the actual in iteration_directory.  */
 162           add_chdir (&actions, "..", do_fchdir, 5);
 163           TEST_COMPARE (posix_spawn_file_actions_addopen
 164                         (&actions, STDOUT_FILENO, "output-file",
 165                          O_WRONLY | O_CREAT | O_EXCL, 0777), 0);
 166
 167           /* Check that posix_spawn_file_actions_addchdir_np made a copy
 168              of the path.  */
 169           if (do_overwrite)
 170             subdir_path[0] = '\0';
 171
 172           char *const argv[] = { (char *) "pwd", NULL };
 173           char *const envp[] = { NULL } ;
 174           PID_T_TYPE pid;
 175           if (do_spawnp)
 176             TEST_COMPARE (POSIX_SPAWNP (&pid, "pwd", &actions,
 177                                         NULL, argv, envp), 0);
 178           else
 179             TEST_COMPARE (POSIX_SPAWN (&pid, "subdir/pwd-symlink", &actions,
 180                                        NULL, argv, envp), 0);
 181           TEST_VERIFY (pid > 0);
 182           siginfo_t sinfo;
 183           TEST_COMPARE (WAITID (P_ALL, 0, &sinfo, WEXITED), 0);
 184           TEST_COMPARE (sinfo.si_code, CLD_EXITED);
 185           TEST_COMPARE (sinfo.si_status, 0);
 186
 187           /* Check that the current directory did not change.  */
 188           {
 189             char *cwd = get_current_dir_name ();
 190             if (cwd == NULL)
 191               FAIL_EXIT1 ("get_current_dir_name: %m");
 192             TEST_COMPARE_BLOB (original_cwd, strlen (original_cwd),
 193                                cwd, strlen (cwd));
 194             free (cwd);
 195           }
 196
 197
 198           /* Check the output from "pwd".  */
 199           {
 200             char *pwd = read_one_line (output_file_path);
 201             TEST_COMPARE_BLOB (iteration_directory, strlen (iteration_directory),
 202                                pwd, strlen (pwd));
 203             free (pwd);
 204           }
 205
 206           /* This file must now exist.  */
 207           TEST_COMPARE (access (probe_file_path, F_OK), 0);
 208
 209           TEST_COMPARE (posix_spawn_file_actions_destroy (&actions), 0);
 210           free (pwd_symlink_path);
 211           free (probe_file_path);
 212           free (subdir_path);
 213           free (output_file_path);
 214         }
 215
 216   free (directory);
 217
 218   return 0;
 219 }
 220
 221 #include <support/test-driver.c>