File Coverage

blib/lib/Net/CIDR/Set.pm

Criterion	Covered	Total	%
statement	207	228	90.7
branch	51	60	85.0
condition	17	29	58.6
subroutine	42	49	85.7
pod	25	26	96.1
total	342	392	87.2

package Net::CIDR::Set;

# ABSTRACT: Manipulate sets of IP addresses

use v5.14;
use warnings;

use Carp qw( croak confess );
use Net::CIDR::Set::IPv4;
use Net::CIDR::Set::IPv6;

use overload '""' => 'as_string';

use namespace::autoclean;

our $VERSION = '0.19';


{
  my %type_map = (
    ipv4 => 'Net::CIDR::Set::IPv4',
    ipv6 => 'Net::CIDR::Set::IPv6',
  );

  sub new {
    my $self  = shift;
    my $class = ref $self || $self;
    my $set   = bless { ranges => [] }, $class;
    my $opt   = 'HASH' eq ref $_[0] ? shift : {};
    if ( defined( my $type = delete $opt->{type} ) ) {
      my $coder_class = $type_map{$type} || $type;
      $set->{coder} = $coder_class->new;
    }
    elsif ( ref $self ) {
      $set->{coder} = $self->{coder};
    }
    my @unk = keys %$opt;
    croak "Unknown options: ", _and( sort @unk ) if @unk;
    $set->add( @_ ) if @_;
    return $set;
  }
}

# Return the index of the first element >= the supplied value. If the
# supplied value is larger than any element in the list the returned
# value will be equal to the size of the list.
sub _find_pos {
  my $self = shift;
  my $val  = shift;
  my $low  = shift || 0;

  my $high = scalar( @{ $self->{ranges} } );

  while ( $low < $high ) {
    my $mid = int( ( $low + $high ) / 2 );
    my $cmp = $val cmp $self->{ranges}[$mid];
    if ( $cmp < 0 ) {
      $high = $mid;
    }
    elsif ( $cmp > 0 ) {
      $low = $mid + 1;
    }
    else {
      return $mid;
    }
  }

  return $low;
}

sub _inc {
  my @b = reverse unpack 'C*', shift;
  for ( @b ) {
    last unless ++$_ == 256;
    $_ = 0;
  }
  return pack 'C*', reverse @b;
}

sub _dec {
  my @b = reverse unpack 'C*', shift;
  for ( @b ) {
    last unless $_-- == 0;
    $_ = 255;
  }
  return pack 'C*', reverse @b;
}

sub _guess_coder {
  my ( $self, $ip ) = @_;
  for my $class ( qw( Net::CIDR::Set::IPv4 Net::CIDR::Set::IPv6 ) ) {
    my $coder = $class->new;
    ( eval { $coder->encode( $ip ) } );
    return $coder unless $@;
  }
  croak "Can't decode $ip as an IPv4 or IPv6 address";
}

sub _encode {
  my ( $self, $ip ) = @_;
  my $cdr = $self->{coder} ||= $self->_guess_coder( $ip );
  return $cdr->encode( $ip );
}

{
  for my $dele ( qw( _decode _nbits ) ) {
    no strict 'refs'; ## no critic (ProhibitNoStrict)
    my $meth = $dele =~ s/^_//r;
    *{$dele} = sub {
      my $self = shift;
      my $cdr = $self->{coder} || croak "Don't know how to $meth yet";
      return $cdr->$meth( @_ );
    };
  }
}

sub _conjunction {
  my ( $conj, @list ) = @_;
  my $last = pop @list;
  return join " $conj ", join( ', ', @list ), $last;
}

sub _and { _conjunction( 'and', @_ ) }

sub _check_and_coerce {
  my ( $self, @others ) = @_;

  my %class = map {
    eval { ( defined $_ && $_->nbits || '' ) => $_ }
  } map { $_->{coder} } grep { defined } $self, @others;

  my @found = sort grep $_, keys %class;

  croak "Can't mix ", _and( @found ), " bit addresses"
   if @found > 1;

  $self->{coder} ||= $class{ $found[0] };
  return $self;
}


sub invert {
  my $self = shift;

  my @pad = ( 0 ) x ( $self->_nbits / 8 );
  my ( $min, $max ) = map { pack 'C*', $_, @pad } 0, 1;

  if ( $self->is_empty ) {
    $self->{ranges} = [ $min, $max ];
    return;
  }

  if ( $self->{ranges}[0] eq $min ) {
    shift @{ $self->{ranges} };
  }
  else {
    unshift @{ $self->{ranges} }, $min;
  }

  if ( $self->{ranges}[-1] eq $max ) {
    pop @{ $self->{ranges} };
  }
  else {
    push @{ $self->{ranges} }, $max;
  }
}


sub copy {
  my $self = shift;
  my $copy = $self->new;
  @{ $copy->{ranges} } = @{ $self->{ranges} };
  return $copy;
}

sub _add_range {
  my ( $self, $from, $to ) = @_;
  my $fpos = $self->_find_pos( $from );
  my $tpos = $self->_find_pos( _inc( $to ), $fpos );

  $from = $self->{ranges}[ --$fpos ] if ( $fpos & 1 );
  $to   = $self->{ranges}[ $tpos++ ] if ( $tpos & 1 );

  splice @{ $self->{ranges} }, $fpos, $tpos - $fpos, ( $from, $to );
}


sub add {
  my ( $self, @addr ) = @_;
  for my $ip ( map { split /\s*,\s*/ } @addr ) {
    my ( $lo, $hi ) = $self->_encode( $ip )
     or croak "Can't decode $ip";
    $self->_add_range( $lo, $hi );
  }
}


sub remove {
  my $self = shift;

  $self->invert;
  $self->add( @_ );
  $self->invert;
}


sub merge {
  my $self = shift;
  $self->_check_and_coerce( @_ );

  # TODO: This isn't very efficient - and merge gets called from all
  # sorts of other places.
  for my $other ( @_ ) {
    my $iter = $other->_iterate_runs;
    while ( my ( $from, $to ) = $iter->() ) {
      $self->_add_range( $from, $to );
    }
  }
}


*contains = *contains_all;

sub contains_all {
  my $self  = shift;
  my $class = ref $self;
  return $class->new( @_ )->subset( $self );
}


sub contains_any {
  my $self  = shift;
  my $class = ref $self;
  return !$class->new( @_ )->intersection( $self )->is_empty;
}

sub _iterate_runs {
  my $self = shift;

  my $pos   = 0;
  my $limit = scalar( @{ $self->{ranges} } );

  return sub {
    return if $pos >= $limit;
    my @r = @{ $self->{ranges} }[ $pos, $pos + 1 ];
    $pos += 2;
    return @r;
  };
}

sub compliment {
  croak "That's very kind of you - but I expect you meant complement";
}


sub complement {
  my $new = shift->copy;
  # TODO: What if it's empty?
  $new->invert;
  return $new;
}


sub union {
  my $new = shift->copy;
  $new->merge( @_ );
  return $new;
}


sub intersection {
  my $self  = shift;
  my $class = ref $self;
  my $new   = $class->new;
  $new->merge( map { $_->complement } $self, @_ );
  $new->invert;
  return $new;
}


sub xor {
  my $self = shift;
  return $self->union( @_ )
   ->intersection( $self->intersection( @_ )->complement );
}


sub diff {
  my $self  = shift;
  my $other = shift;
  return $self->intersection( $other->union( @_ )->complement );
}


sub is_empty {
  my $self = shift;
  return @{ $self->{ranges} } == 0;
}


sub superset {
  my $other = pop;
  return $other->subset( reverse( @_ ) );
}


sub subset {
  my $self = shift;
  my $other = shift || croak "I need two sets to compare";
  return $self->equals( $self->intersection( $other ) );
}


sub equals {
  return unless @_;

  # Array of array refs
  my @edges = map { $_->{ranges} } @_;
  my $medge = scalar( @edges ) - 1;

  POS: for ( my $pos = 0;; $pos++ ) {
    my $v = $edges[0]->[$pos];
    if ( defined( $v ) ) {
      for ( @edges[ 1 .. $medge ] ) {
        my $vv = $_->[$pos];
        return unless defined( $vv ) && $vv eq $v;
      }
    }
    else {
      for ( @edges[ 1 .. $medge ] ) {
        return if defined $_->[$pos];
      }
    }

    last POS unless defined( $v );
  }

  return 1;
}


sub iterate_addresses {
  my ( $self, @args ) = @_;
  my $iter = $self->_iterate_runs;
  my @r    = ();
  return sub {
    while ( 1 ) {
      @r = $iter->() or return unless @r;
      return $self->_decode( ( my $last, $r[0] )
        = ( $r[0], _inc( $r[0] ) ), @args )
       unless $r[0] eq $r[1];
      @r = ();
    }
  };
}


sub iterate_cidr {
  my ( $self, @args ) = @_;
  my $iter = $self->_iterate_runs;
  my $size = $self->_nbits;
  my @r    = ();
  return sub {
    while ( 1 ) {
      @r = $iter->() or return unless @r;
      unless ( $r[0] eq $r[1] ) {
        ( my $bits = unpack 'B*', $r[0] ) =~ /(0*)$/;
        my $pad = length $1;
        $pad = $size if $pad > $size;
        while ( 1 ) {
          my $next = _inc( $r[0] | pack 'B*',
            ( '0' x ( length( $bits ) - $pad ) ) . ( '1' x $pad ) );
          return $self->_decode( ( my $last, $r[0] ) = ( $r[0], $next ),
            @args )
           if $next le $r[1];
          $pad--;
        }
      }
      @r = ();
    }
  };
}


sub iterate_ranges {
  my ( $self, @args ) = @_;
  my $iter = $self->_iterate_runs;
  return sub {
    return unless my @r = $iter->();
    return $self->_decode( @r, @args );
  };
}


sub as_array {
  my ( $self, $iter ) = @_;
  my @addr = ();
  while ( my $addr = $iter->() ) {
    push @addr, $addr;
  }
  return @addr;
}


sub as_address_array {
  my $self = shift;
  return $self->as_array( $self->iterate_addresses( @_ ) );
}


sub as_cidr_array {
  my $self = shift;
  return $self->as_array( $self->iterate_cidr( @_ ) );
}


sub as_range_array {
  my $self = shift;
  return $self->as_array( $self->iterate_ranges( @_ ) );
}


sub as_string { join ', ', shift->as_range_array( @_ ) }

1;

__END__