Introduce SortAddressHash function.

[people/stevee/guardian.git] / modules / Base.pm

diff --git a/modules/Base.pm b/modules/Base.pm
index 2f5e73773bc825d21c6000d54d33cd2daba5f130..41ac981f9eb41786fba4430392cef8eac851a4f1 100644 (file)
--- a/modules/Base.pm
+++ b/modules/Base.pm
@@ -4,7 +4,9 @@ use warnings;
 
 use Exporter qw(import);
 
-our @EXPORT_OK = qw(GenerateMonitoredFiles FilePositions);
+our @EXPORT_OK = qw(GenerateMonitoredFiles GetFileposition DetectIPProtocolVersion FilePositions);
+
+use Net::IP;
 
 #
 ## Function to generate a hash of monitored files and their file positions.
@@ -105,7 +107,7 @@ sub FilePositions (\%\%) {
                        $new_file_positions{$file} = $current_file_positions{$file};
                } else {
                        # Call function to obtain the file position.
-                       my $position = &_initFileposition($file);
+                       my $position = &GetFileposition($file);
 
                        # Add filename and position to the temporary hash.
                        $new_file_positions{$file} = $position;
@@ -117,7 +119,77 @@ sub FilePositions (\%\%) {
 }
 
 #
-## Function for fileposition initialization.
+## Address/Network to binary format caluculator function.
+#
+## This function is used to convert a given single IP address
+## or network into a binary format.
+#
+## The used Net::IP module is not able to directly detect
+## single addresses or network ranges. Only an element which may be
+## a single address or a whole network can be assigned, for which a
+## lot of different values can be calculated. In case the input has
+## been a single address, the module will calculate the same binary
+## address (intip) and last address for the network range (last_int)
+## because internally it uses a /32 bit prefix for IPv4 and a /128 prefix
+## on IPv6 addresses.
+#
+## So a single address can be detected by just comparing both calculated
+## addresses if they are equal.
+#
+sub IPOrNet2Int($) {
+       my $address = shift;
+
+       # Assign and validate the given address, or directly return
+       # nothing (False) and exit the function.
+       my $ip = new Net::IP ($address) || return;
+
+       # Convert the given address into integer format.
+       my $first .= $ip->intip();
+
+       # Calculate last address for the given network.
+       my $last .= $ip->last_int();
+
+       # Check whether the first address equals the last address.
+       # If this is true, a single IP address has been passed.
+       if ($first eq $last) {
+               # Return the binary converted single address.
+               return $first;
+       }
+
+       # If both addresses are not equal a network has been passed.
+       #
+       # Check if the converted first address is less than the calculated last
+       # address of the network.
+       elsif ($first < $last) {
+               # Return the binary converted first and last address of
+               # the given network.
+               return $first, $last;
+       }
+
+       # If we got here, something strange happend, return nothing (False).
+       else {
+               return;
+       }
+}
+
+#
+## DetectIPProtocolVersion function.
+#
+## Wrapper function for determining the used protocol version (4/6)
+## for a given IP address.
+#
+sub DetectIPProtocolVersion ($) {
+       my $address = shift;
+
+       # Call external perl module to detect the used IP protocol version.
+       my $version = &Net::IP::ip_get_version($address);
+
+       # Return the detected version.
+       return $version;
+}
+
+#
+## Function to get the current (EOF) cursor postion.
 #
 ## This function is used to get the cursor position of the end of file (EOF) of
 ## a specified file.
@@ -126,7 +198,7 @@ sub FilePositions (\%\%) {
 ## with huge logfiles, at initialization time of the worker processes, the file will
 ## be opened once and the cursor position of the end of file (EOF) get stored.
 #
-sub _initFileposition ($) {
+sub GetFileposition ($) {
        my $file = $_[0];
 
        # Open the file.
@@ -145,4 +217,34 @@ sub _initFileposition ($) {
        return $position;
 }
 
+#
+## The SortAddressHash function.
+#
+# This function requires a reference to an hash containing
+# IP-addresses, will sort them into a nice looking order
+# and return the soreted result as an array.
+#
+sub SortAddressHash (\%) {
+       # Dereference the given hash reference and store it
+       # in a new temporary hash.
+       my %addresshash = %{ $_[0] };
+
+       # Loop through the entire hash keys.
+       foreach my $address (keys(%addresshash)) {
+               # Convert the address or subnet into binary format.
+               my @bin_address = &IPOrNet2Int($address);
+
+               # Only store the first result if there are multiple
+               # one in case of a given subnet.
+               $addresshash{$address} = $bin_address[0];
+        }
+
+       # Sort the addresshash by the binary addresses
+        # of the stored addresses and save them is an array.
+        my @sorted_addresses = sort { $addresshash{$a} <=> $addresshash{$b} } keys %addresshash;
+
+        # Return the sorted address array.
+        return @sorted_addresses;
+}
+
 1;