io/tst-ftw-lnk.c

   1 /* Test for ftw function related to symbolic links for BZ #23501
   2    Copyright (C) 2019-2023 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 <ftw.h>
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <unistd.h>
  25 #include <fcntl.h>
  26 #include <errno.h>
  27
  28 #include <support/support.h>
  29 #include <support/check.h>
  30
  31 #define TSTDIR "tst-ftw-lnk.d"
  32
  33 static void
  34 un (const char *file)
  35 {
  36   struct stat st;
  37   /* Does the file exist?  */
  38   if (lstat (file, &st) < 0
  39       && errno == ENOENT)
  40     return;
  41
  42   /* If so, try to remove it.  */
  43   if (unlink (file) < 0)
  44     FAIL_EXIT1 ("Unable to unlink %s", file);
  45 }
  46
  47 static void
  48 debug_cb (const char *which, const char *fpath,
  49           const struct stat *sb, int typeflags)
  50 {
  51   const char *sb_type = "???";
  52   const char *ftw_type = "???";
  53
  54   /* Coding style here is intentionally "wrong" to increase readability.  */
  55   if (S_ISREG (sb->st_mode))  sb_type = "REG";
  56   if (S_ISDIR (sb->st_mode))  sb_type = "DIR";
  57   if (S_ISLNK (sb->st_mode))  sb_type = "LNK";
  58
  59   if (typeflags == FTW_F)   ftw_type = "F";
  60   if (typeflags == FTW_D)   ftw_type = "D";
  61   if (typeflags == FTW_DNR) ftw_type = "DNR";
  62   if (typeflags == FTW_DP)  ftw_type = "DP";
  63   if (typeflags == FTW_NS)  ftw_type = "NS";
  64   if (typeflags == FTW_SL)  ftw_type = "SL";
  65   if (typeflags == FTW_SLN) ftw_type = "SLN";
  66
  67   printf ("%s %5d %-3s %-3s %s\n", which, (int)(sb->st_ino % 100000), sb_type, ftw_type, fpath);
  68 }
  69
  70 int good_cb = 0;
  71 #define EXPECTED_GOOD 12
  72
  73 /* See if the stat buffer SB refers to the file AS_FNAME.  */
  74 static void
  75 check_same_stats (const struct stat *sb, const char *as_fname)
  76 {
  77   struct stat as;
  78   if (lstat (as_fname, &as) < 0)
  79     FAIL_EXIT1 ("unable to stat %s for comparison", as_fname);
  80
  81   if (as.st_mode == sb->st_mode
  82       && as.st_ino == sb->st_ino
  83       && as.st_size == sb->st_size)
  84     good_cb ++;
  85   else
  86     printf ("statbuf data doesn't match %s\n", as_fname);
  87 }
  88
  89 static int
  90 callback_phys (const char *fpath, const struct stat *sb, int typeflags, struct FTW *ftwbuf)
  91 {
  92   debug_cb ("P", fpath, sb, typeflags);
  93
  94   /* This callback is for when the FTW_PHYS flag is set.  The results
  95      should reflect the physical filesystem entry, not what it might
  96      point to.  */
  97
  98   /* link1-bad is a dangling symlink, but we're reporting on the link
  99      anyway (ala lstat ()).  */
 100   if (strcmp (fpath, "./link1-bad") == 0)
 101     {
 102       if (S_ISLNK (sb->st_mode) && typeflags == FTW_SL)
 103         good_cb ++;
 104       else
 105         printf ("link1-bad had wrong phys stats\n");
 106
 107       check_same_stats (sb, "link1-bad");
 108     }
 109
 110   /* link2-ok is a regular non-dangling symlink.  */
 111   if (strcmp (fpath, "./link2-ok") == 0)
 112     {
 113       if (S_ISLNK (sb->st_mode) && typeflags == FTW_SL)
 114         good_cb ++;
 115       else
 116         printf ("link2-ok had wrong phys stats\n");
 117
 118       check_same_stats (sb, "link2-ok");
 119     }
 120
 121   /* This is the file link2-ok points to.  */
 122   if (strcmp (fpath, "./link2-tgt") == 0)
 123     {
 124       if (S_ISREG (sb->st_mode) && typeflags == FTW_F)
 125         good_cb ++;
 126       else
 127         printf ("link2-tgt had wrong phys stats\n");
 128
 129       check_same_stats (sb, "link2-tgt");
 130     }
 131
 132   return 0;
 133 }
 134
 135 static int
 136 callback_log (const char *fpath, const struct stat *sb, int typeflags, struct FTW *ftwbuf)
 137 {
 138   debug_cb ("L", fpath, sb, typeflags);
 139
 140   /* This callback is for when the FTW_PHYS flags is NOT set.  The
 141      results should reflect the logical file, i.e. symlinks should be
 142      followed.  */
 143
 144   /* We would normally report what link1-bad links to, but link1-bad
 145      is a dangling symlink.  This is an exception to FTW_PHYS in that
 146      we report FTW_SLN (dangling symlink) but the stat data is
 147      correctly set to the link itself (ala lstat ()).  */
 148   if (strcmp (fpath, "./link1-bad") == 0)
 149     {
 150       if (S_ISLNK (sb->st_mode) && typeflags == FTW_SLN)
 151         good_cb ++;
 152       else
 153         printf ("link1-bad had wrong logical stats\n");
 154
 155       check_same_stats (sb, "link1-bad");
 156     }
 157
 158   /* link2-ok points to link2-tgt, so we expect data reflecting
 159      link2-tgt (ala stat ()).  */
 160   if (strcmp (fpath, "./link2-ok") == 0)
 161     {
 162       if (S_ISREG (sb->st_mode) && typeflags == FTW_F)
 163         good_cb ++;
 164       else
 165         printf ("link2-ok had wrong logical stats\n");
 166
 167       check_same_stats (sb, "link2-tgt");
 168     }
 169
 170   /* This is the file link2-ok points to.  */
 171   if (strcmp (fpath, "./link2-tgt") == 0)
 172     {
 173       if (S_ISREG (sb->st_mode) && typeflags == FTW_F)
 174         good_cb ++;
 175       else
 176         printf ("link2-tgt had wrong logical stats\n");
 177
 178       check_same_stats (sb, "link2-tgt");
 179     }
 180
 181   return 0;
 182 }
 183
 184 static int
 185 do_test (void)
 186 {
 187   struct stat st;
 188
 189   if (chdir (support_objdir_root) < 0)
 190     FAIL_EXIT1 ("cannot chdir to objdir root");
 191
 192   if (chdir ("io") < 0)
 193     FAIL_EXIT1 ("cannot chdir to objdir/io subdir");
 194
 195   if (stat (TSTDIR, &st) >= 0)
 196     {
 197       /* Directory does exist, delete any potential conflicts. */
 198       if (chdir (TSTDIR) < 0)
 199         FAIL_EXIT1 ("cannot chdir to %s\n", TSTDIR);
 200       un ("link1-bad");
 201       un ("link1-tgt");
 202       un ("link2-ok");
 203       un ("link2-tgt");
 204     }
 205   else
 206     {
 207       /* Directory does not exist, create it.  */
 208       mkdir (TSTDIR, 0777);
 209       if (chdir (TSTDIR) < 0)
 210         FAIL_EXIT1 ("cannot chdir to %s\n", TSTDIR);
 211     }
 212
 213   /* At this point, we're inside our test directory, and need to
 214      prepare it.  */
 215
 216   if (symlink ("link1-tgt", "link1-bad") < 0)
 217     FAIL_EXIT1 ("symlink link1-bad failed");
 218   if (symlink ("link2-tgt", "link2-ok") < 0)
 219     FAIL_EXIT1 ("symlink link2-ok failed");
 220   if (open ("link2-tgt", O_RDWR|O_CREAT, 0777) < 0)
 221     FAIL_EXIT1 ("create of link2-tgt failed");
 222
 223   /* Now we run the tests.  */
 224
 225   nftw (".", callback_phys, 10, FTW_PHYS);
 226   nftw (".", callback_log, 10, 0);
 227
 228   /* Did we see the expected number of correct callbacks? */
 229
 230   if (good_cb != EXPECTED_GOOD)
 231     {
 232       FAIL_EXIT1 ("Saw %d good callbacks, expected %d\n",
 233                   good_cb, EXPECTED_GOOD);
 234     }
 235
 236   return 0;
 237 }
 238
 239 #include <support/test-driver.c>