diff options
Diffstat (limited to 'fml/libexec')
| -rw-r--r-- | fml/libexec/Standalone.pm | 43 |
1 files changed, 37 insertions, 6 deletions
diff --git a/fml/libexec/Standalone.pm b/fml/libexec/Standalone.pm index 46dae660..069e7e3a 100644 --- a/fml/libexec/Standalone.pm +++ b/fml/libexec/Standalone.pm @@ -65,15 +65,46 @@ sub load_cf sub _expand_variables { my ($config) = @_; + my @order = keys %$config; - # expand $xxx style variables - no strict 'refs'; - for my $x (keys %$config) { $$x = $config->{ $x };} - for (keys %$config) { - $config->{ $_ } =~ s/\$([a-z_]+)/${$1}/g; + # check whether the variable definition is recursive. + # For example, definition "var_a = $var_a/b/c" causes a loop. + for my $x ( @order ) { + if ($config->{ $x } =~ /\$$x/) { + croak("loop1: definition of $x is recursive\n"); + } } -} + # main expansion loop + my $org = ''; + my $max = 0; + KEY: + for my $x ( @order ) { + next KEY if $config->{ $x } !~ /\$/o; + + # we need a loop to expand nested variables, for example, + # a = $x/y and b = $a/c/0 + # + $max = 0; + EXPANSION_LOOP: + while ($max++ < 16) { + $org = $config->{ $x }; + + $config->{ $x } =~ s/\$([a-z_]+)/$config->{$1}/g; + + last EXPANSION_LOOP if $config->{ $x } !~ /\$/o; + last EXPANSION_LOOP if $org eq $config->{ $x }; + + if ($config->{ $x } =~ /\$$x/) { + croak("loop2: definition of $x is recursive\n"); + } + } + + if ($max >= 16) { + croak("variable expansion of $x causes infinite loop\n"); + } + } +} sub _parse_params |