posix/tst-glob_symlinks.c

   1 /* Test glob danglin symlink match (BZ #866).
   2    Copyright (C) 2017-2023 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 <stdio.h>
  20 #include <string.h>
  21 #include <stdlib.h>
  22 #include <errno.h>
  23 #include <unistd.h>
  24 #include <limits.h>
  25 #include <stddef.h>
  26 #include <glob.h>
  27 #include <sys/stat.h>
  28 #include <sys/types.h>
  29
  30 #include <support/check.h>
  31 #include <support/temp_file.h>
  32
  33 static void do_prepare (int argc, char *argv[]);
  34 #define PREPARE do_prepare
  35 static int do_test (void);
  36 #include <support/test-driver.c>
  37
  38 /* Maximum number of symlink calls for create_link function.  */
  39 #define MAX_CREATE_LINK_TRIES 10
  40
  41 static void
  42 create_link (const char *base, const char *fname, char *linkname,
  43              size_t linknamesize)
  44 {
  45   int ntries = 0;
  46   while (1)
  47     {
  48       snprintf (linkname, linknamesize, "%s/%s%02d", test_dir, base,
  49                 ntries);
  50       if (symlink (fname, linkname) == 0)
  51         break;
  52       if (errno != EEXIST)
  53         FAIL_EXIT1 ("symlink failed: %m");
  54       if (ntries++ == MAX_CREATE_LINK_TRIES)
  55         FAIL_EXIT1 ("symlink failed with EEXIST too many times");
  56     }
  57   add_temp_file (linkname);
  58 }
  59
  60 #ifndef PATH_MAX
  61 # define PATH_MAX 1024
  62 #endif
  63 static char valid_link[PATH_MAX];
  64 static char dangling_link[PATH_MAX];
  65 static char dangling_dir[PATH_MAX];
  66
  67 static void
  68 do_prepare (int argc, char *argv[])
  69 {
  70   char *fname;
  71
  72   create_temp_file ("tst-glob_symlinks.", &fname);
  73
  74   /* Create an existing symlink.  */
  75   create_link ("valid-symlink-tst-glob_symlinks", fname, valid_link,
  76                sizeof valid_link);
  77
  78   /* Create a dangling symlink to a file.  */
  79   int fd = create_temp_file ("dangling-tst-glob_file", &fname);
  80   TEST_VERIFY_EXIT (close (fd) == 0);
  81   /* It throws a warning at process end due 'add_temp_file' trying to
  82      unlink it again.  */
  83   TEST_VERIFY_EXIT (unlink (fname) == 0);
  84   create_link ("dangling-symlink-file-tst-glob", fname, dangling_link,
  85                sizeof dangling_link);
  86
  87   /* Create a dangling symlink to a directory.  */
  88   char tmpdir[PATH_MAX];
  89   snprintf (tmpdir, sizeof tmpdir, "%s/dangling-tst-glob_folder.XXXXXX",
  90             test_dir);
  91   TEST_VERIFY_EXIT (mkdtemp (tmpdir) != NULL);
  92   create_link ("dangling-symlink-dir-tst-glob", tmpdir, dangling_dir,
  93                sizeof dangling_dir);
  94   TEST_VERIFY_EXIT (rmdir (tmpdir) == 0);
  95 }
  96
  97 static int
  98 do_test (void)
  99 {
 100   char buf[PATH_MAX + 1];
 101   glob_t gl;
 102
 103   TEST_VERIFY_EXIT (glob (valid_link, 0, NULL, &gl) == 0);
 104   TEST_VERIFY_EXIT (gl.gl_pathc == 1);
 105   TEST_VERIFY_EXIT (strcmp (gl.gl_pathv[0], valid_link) == 0);
 106   globfree (&gl);
 107
 108   TEST_VERIFY_EXIT (glob (dangling_link, 0, NULL, &gl) == 0);
 109   TEST_VERIFY_EXIT (gl.gl_pathc == 1);
 110   TEST_VERIFY_EXIT (strcmp (gl.gl_pathv[0], dangling_link) == 0);
 111   globfree (&gl);
 112
 113   TEST_VERIFY_EXIT (glob (dangling_dir, 0, NULL, &gl) == 0);
 114   TEST_VERIFY_EXIT (gl.gl_pathc == 1);
 115   TEST_VERIFY_EXIT (strcmp (gl.gl_pathv[0], dangling_dir) == 0);
 116   globfree (&gl);
 117
 118   snprintf (buf, sizeof buf, "%s", dangling_link);
 119   buf[strlen(buf) - 1] = '?';
 120   TEST_VERIFY_EXIT (glob (buf, 0, NULL, &gl) == 0);
 121   TEST_VERIFY_EXIT (gl.gl_pathc == 1);
 122   TEST_VERIFY_EXIT (strcmp (gl.gl_pathv[0], dangling_link) == 0);
 123   globfree (&gl);
 124
 125   /* glob should handle dangling symbol as normal file, so <file>? should
 126      return an empty string.  */
 127   snprintf (buf, sizeof buf, "%s?", dangling_link);
 128   TEST_VERIFY_EXIT (glob (buf, 0, NULL, &gl) != 0);
 129   globfree (&gl);
 130
 131   snprintf (buf, sizeof buf, "%s*", dangling_link);
 132   TEST_VERIFY_EXIT (glob (buf, 0, NULL, &gl) == 0);
 133   TEST_VERIFY_EXIT (gl.gl_pathc == 1);
 134   TEST_VERIFY_EXIT (strcmp (gl.gl_pathv[0], dangling_link) == 0);
 135   globfree (&gl);
 136
 137   return 0;
 138 }