src/test/bindmount_test.pl

   1 #!/usr/bin/perl
   2
   3 use strict;
   4 use warnings;
   5
   6 use Cwd;
   7 use File::Path;
   8
   9 use lib qw(..);
  10
  11 use PVE::LXC;
  12
  13 my $pwd = getcwd();
  14
  15 my $rootdir = "./tmproot";
  16 my $destdir = "/mnt";
  17
  18 my $sharedir = "/tmpshare";
  19 my $a        = "/tmpshare/a";
  20 my $ab       = "/tmpshare/a/b";
  21 my $abc      = "/tmpshare/a/b/c";
  22 my $sym      = "/tmpshare/sym";
  23 my $tmp      = "/tmpshare/tmp";
  24
  25 my $secret = "/secret";
  26
  27 END { cleanup(); };
  28 sub cleanup {
  29     my $ignore_error;
  30     File::Path::rmtree("$pwd/$rootdir", {error => \$ignore_error});
  31     File::Path::rmtree("$pwd/$sharedir", {error => \$ignore_error});
  32     File::Path::rmtree("$pwd/$secret", {error => \$ignore_error});
  33 }
  34
  35 sub setup {
  36     # Create all the test paths...
  37     PVE::LXC::walk_tree_nofollow('.', $rootdir, 1);
  38     PVE::LXC::walk_tree_nofollow($rootdir, $destdir, 1);
  39     PVE::LXC::walk_tree_nofollow('.', $abc, 1);
  40     PVE::LXC::walk_tree_nofollow('.', $secret, 1);
  41     # Create one evil symlink
  42     symlink('a/b', "$pwd/$sym") or die "failed to prepare test folders: $!\n";
  43 }
  44
  45 setup();
  46
  47 # Test walk_tree_nofollow:
  48 eval { PVE::LXC::walk_tree_nofollow('.', $rootdir, 0) };
  49 die "unexpected error: $@" if $@;
  50 eval { PVE::LXC::walk_tree_nofollow('.', "$sym/c", 0) };
  51 die "failed to catch symlink at $sym/c\n" if !$@;
  52 die "unexpected test error: '$@'\n" if $@ ne "symlink encountered at: .$sym\n";
  53
  54 # Bindmount testing:
  55 sub bindmount {
  56     my ($from, $rootdir, $destdir, $inject, $ro, $inject_write, $restore) = @_;
  57
  58     my ($mpath, $mpfd, $parentfd, $last);
  59     ($rootdir, $mpath, $mpfd, $parentfd, $last) =
  60         PVE::LXC::__mount_prepare_rootdir($rootdir, $destdir);
  61
  62     my $srcdh = PVE::LXC::__bindmount_prepare('.', $from);
  63
  64     if ($inject) {
  65         if ($restore) {
  66             rename(".$inject", ".$tmp")
  67                 or die "failed to move directory: $!\n";
  68         } else {
  69             File::Path::rmtree(".$inject");
  70         }
  71         symlink("$pwd/$secret", ".$inject")
  72             or die "failed to create symlink\n";
  73         File::Path::mkpath(".$from");
  74     }
  75     eval {
  76         PVE::LXC::__bindmount_do(".$from", $mpath, $inject_write ? 0 : $ro);
  77
  78         if ($restore) {
  79             unlink(".$inject") or die "failed to restore path: $!\n";
  80             rename(".$tmp", ".$inject") or die "failed to restore path: $!\n";
  81         }
  82
  83         PVE::LXC::__bindmount_verify($srcdh, $parentfd, $last, $ro)
  84             or die "bindmount verification failed\n";
  85     };
  86     my $err = $@;
  87     system('umount', $mpath);
  88     die $err if $err;
  89 }
  90
  91 bindmount($a, $rootdir, $destdir, undef, 0, 0);
  92 eval { bindmount($sym, $rootdir, $destdir, undef, 0, 0) };
  93 die "illegal symlink bindmount went through\n" if !$@;
  94 die "unexpected test error: $@\n" if $@ ne "symlink encountered at: .$sym\n";
  95 bindmount($abc, $rootdir, $destdir, undef, 0, 0);
  96 # Race test: Assume someone exchanged 2 equivalent bind mounts between and
  97 # after the bindmount_do()'s mount and remount calls.
  98 # First: non-ro mount, should pass
  99 bindmount($abc, $rootdir, $destdir, undef, 0, 1);
 100 # Second: regular read-only mount, should pass.
 101 bindmount($abc, $rootdir, $destdir, undef, 1, 0);
 102 # Third: read-only requested with read-write injected
 103 eval { bindmount($abc, $rootdir, $destdir, undef, 1, 1) };
 104 die "read-write mount possible\n" if !$@;
 105 die "unexpected test error: $@\n" if $@ ne "failed to mark bind mount read only\n";
 106 # Race test: Replace /tmpshare/a/b with a symlink to /secret just before
 107 # __bindmount_do().
 108 eval { bindmount($abc, $rootdir, $destdir, $ab, 0, 0) };
 109 die "injected symlink bindmount went through\n" if !$@;
 110 die "unexpected test error: $@\n" if $@ ne "bindmount verification failed\n";
 111 # Restore setup:
 112 cleanup();
 113 setup();
 114 # Race test 2: As above but also reset the symlink back after __bindmount_do()
 115 eval { bindmount($abc, $rootdir, $destdir, $ab, 0, 0, 1) };
 116 die "injected symlink bindmount went through\n" if !$@;
 117 die "unexpected test error: $@\n" if $@ ne "bindmount verification failed\n";