firewall: rules.pl: Cleanup rule generation.

Various perl coding errors that have been suppressed by "no warnings uninitialized"
have been fixed and lots of helper variables have been introduced to make
it much more clearer what the code is actually doing.

diff --git a/config/firewall/rules.pl b/config/firewall/rules.pl
index 6b22ea378a97ef8feb7358abff923d73634c92ea..523f6e3422c28cadf746284f9928b729ce8217aa 100755 (executable)
--- a/config/firewall/rules.pl
+++ b/config/firewall/rules.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/perl -w
 ###############################################################################
 #                                                                             #
 # IPFire.org - A linux based firewall                                         #
@@ -21,7 +21,6 @@
 
 use strict;
 use Time::Local;
-no warnings 'uninitialized';
 
 require '/var/ipfire/general-functions.pl';
 require "${General::swroot}/lang.pl";
@@ -32,6 +31,11 @@ my $DEBUG = 0;
 
 my $IPTABLES = "iptables --wait";
 
+# iptables chains
+my $CHAIN                 = "FORWARDFW";
+my $CHAIN_NAT_SOURCE      = "NAT_SOURCE";
+my $CHAIN_NAT_DESTINATION = "NAT_DESTINATION";
+
 my %fwdfwsettings=();
 my %defaultNetworks=();
 my %configfwdfw=();
@@ -59,8 +63,7 @@ my $errormessage      = '';
 my $orange                     = '';
 my $green                      = '';
 my $blue                       = '';
-my ($TYPE,$PROT,$SPROT,$DPROT,$SPORT,$DPORT,$TIME,$TIMEFROM,$TIMETILL,$SRC_TGT);
-my $CHAIN                      = "FORWARDFW";
+my ($TYPE,$PROT,$SPROT,$DPROT,$SPORT,$DPORT,$SRC_TGT);
 my $conexists          = 'off';
 my $dnat                       ='';
 my $snat                       ='';
@@ -114,6 +117,12 @@ sub run {
        }
 }
 
+sub print_error {
+       my $message = shift;
+
+       print STDERR "$message\n";
+}
+
 sub flush {
        run("$IPTABLES -F FORWARDFW");
        run("$IPTABLES -F INPUTFW");
@@ -137,29 +146,55 @@ sub preparerules {
 sub buildrules {
        my $hash=shift;
        my $STAG;
-       my $natip;
        my $snatport;
        my $fireport;
-       my $nat;
        my $fwaccessdport;
        my $natchain;
        my $icmptype;
        foreach my $key (sort {$a <=> $b} keys %$hash){
                next if (($$hash{$key}[6] eq 'RED' || $$hash{$key}[6] eq 'RED1') && $conexists eq 'off' );
-               if ($$hash{$key}[28] eq 'ON'){
-                       $natip=&get_nat_ip($$hash{$key}[29],$$hash{$key}[31]);
-                       if($$hash{$key}[31] eq 'dnat'){
-                               $nat='DNAT';
-                               if ($$hash{$key}[30] =~ /\|/){
+
+               my $TIME = "";
+               my $TIMEFROM;
+               my $TIMETILL;
+               my $natip = "";
+
+               # Check if logging should be enabled.
+               my $LOG = 0;
+               if ($$hash{$key}[17] eq 'ON') {
+                       $LOG = 1;
+               }
+
+               my $NAT = 0;
+               my $NAT_MODE;
+
+               # Check if NAT is enabled and initialize variables, that we use for that.
+               if ($$hash{$key}[28] eq 'ON') {
+                       $NAT = 1;
+
+                       # Destination NAT
+                       if ($$hash{$key}[31] eq 'dnat') {
+                               $NAT_MODE = "DNAT";
+
+                               if ($$hash{$key}[30] =~ /\|/) {
                                        $$hash{$key}[30]=~ tr/|/,/;
                                        $fireport='-m multiport --dport '.$$hash{$key}[30];
-                               }else{
+                               } else {
                                        $fireport='--dport '.$$hash{$key}[30] if ($$hash{$key}[30]>0);
                                }
-                       }else{
-                               $nat='SNAT';
+
+                       # Source NAT
+                       } elsif ($$hash{$key}[31] eq 'snat') {
+                               $NAT_MODE = "SNAT";
+
+                       } else {
+                               print_error("Invalid NAT mode: $$hash{$key}[31]");
+                               next;
                        }
+
+                       $natip = &get_nat_ip($$hash{$key}[29], $NAT_MODE);
                }
+
                $STAG='';
                if($$hash{$key}[2] eq 'ON'){
                        #get source ip's
@@ -220,7 +255,7 @@ sub buildrules {
                        #get time if defined
                        if($$hash{$key}[18] eq 'ON'){
                                my ($time1,$time2,$daylight);
-                               my $daylight=$$hash{$key}[28];
+                               $daylight=$$hash{$key}[28];
                                $time1=&get_time($$hash{$key}[26],$daylight);
                                $time2=&get_time($$hash{$key}[27],$daylight);
                                if($$hash{$key}[19] ne ''){push (@timeframe,"Mon");}
@@ -245,7 +280,7 @@ sub buildrules {
                                }
                                foreach my $a (sort keys %sourcehash){
                                        foreach my $b (sort keys %targethash){
-                                               if(! $sourcehash{$a}[0] || ! $targethash{$b}[0] || ($natip eq '-d ' && $$hash{$key}[28] eq 'ON') || (!$natip && $$hash{$key}[28] eq 'ON')){
+                                               if(! $sourcehash{$a}[0] || ! $targethash{$b}[0] || ($natip eq '-d ' && $NAT) || (!$natip && $NAT)){
                                                        #Skip rules when no RED IP is set (DHCP,DSL)
                                                        next;
                                                }
@@ -263,24 +298,23 @@ sub buildrules {
                                                                                                $icmptype="";
                                                                                                $_="";
                                                                                }
-                                                                               if ($$hash{$key}[17] eq 'ON'){
+                                                                               if ($LOG) {
                                                                                        run("$IPTABLES -A $$hash{$key}[1] $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $icmptype $_ $TIME -j LOG");
                                                                                }
-                                                                                       run("$IPTABLES -A $$hash{$key}[1] $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $icmptype $_ $TIME -j $$hash{$key}[0]");
+                                                                               run("$IPTABLES -A $$hash{$key}[1] $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $icmptype $_ $TIME -j $$hash{$key}[0]");
                                                                        }
                                                                #PROCESS DNAT RULE (Portforward)
-                                                               }elsif($$hash{$key}[28] eq 'ON' && $$hash{$key}[31] eq 'dnat'){
-                                                                       $natchain='NAT_DESTINATION';
-                                                                       if ($$hash{$key}[17] eq 'ON'){
-                                                                               run("$IPTABLES -t nat -A $natchain $PROT $STAG $sourcehash{$a}[0] $SPORT $natip $fireport $TIME -j LOG --log-prefix 'DNAT'");
+                                                               } elsif ($NAT && $NAT_MODE eq "DNAT") {
+                                                                       if ($LOG) {
+                                                                               run("$IPTABLES -t nat -A $CHAIN_NAT_DESTINATION $PROT $STAG $sourcehash{$a}[0] $SPORT $natip $fireport $TIME -j LOG --log-prefix 'DNAT'");
                                                                        }
                                                                        my ($ip,$sub) =split("/",$targethash{$b}[0]);
                                                                        #Process NAT with servicegroup used
-                                                                       if ($$hash{$key}[28] eq 'ON' && $$hash{$key}[31] eq 'dnat' && $$hash{$key}[14] eq 'cust_srvgrp'){
-                                                                               run("$IPTABLES -t nat -A $natchain $PROT $STAG $sourcehash{$a}[0] $SPORT $natip $fireport $TIME -j $nat --to-destination $ip $DPORT");
+                                                                       if ($$hash{$key}[14] eq 'cust_srvgrp') {
+                                                                               run("$IPTABLES -t nat -A $CHAIN_NAT_DESTINATION $PROT $STAG $sourcehash{$a}[0] $SPORT $natip $fireport $TIME -j DNAT --to-destination $ip $DPORT");
                                                                                $fwaccessdport=$DPORT;
-                                                                       }else{
-                                                                               run("$IPTABLES -t nat -A $natchain $PROT $STAG $sourcehash{$a}[0] $SPORT $natip $fireport $TIME -j $nat --to-destination $ip$DPORT");
+                                                                       } else {
+                                                                               run("$IPTABLES -t nat -A $CHAIN_NAT_DESTINATION $PROT $STAG $sourcehash{$a}[0] $SPORT $natip $fireport $TIME -j DNAT --to-destination $ip$DPORT");
                                                                                $DPORT =~ s/\-/:/g;
                                                                                if ($DPORT){
                                                                                        $fwaccessdport="--dport ".substr($DPORT,1,);
@@ -296,23 +330,22 @@ sub buildrules {
                                                                        run("$IPTABLES -A FORWARDFW $PROT $STAG $sourcehash{$a}[0] -d $ip $fwaccessdport $TIME -j $$hash{$key}[0]");
                                                                        next;
                                                                #PROCESS SNAT RULE
-                                                               }elsif($$hash{$key}[28] eq 'ON' && $$hash{$key}[31] eq 'snat'){
-                                                                       $natchain='NAT_SOURCE';
-                                                                       if ($$hash{$key}[17] eq 'ON' ){
-                                                                               run("$IPTABLES -t nat -A $natchain $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $DPORT $TIME -j LOG --log-prefix 'SNAT'");
+                                                               } elsif ($NAT && $NAT_MODE eq "SNAT") {
+                                                                       if ($LOG) {
+                                                                               run("$IPTABLES -t nat -A $CHAIN_NAT_SOURCE $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $DPORT $TIME -j LOG --log-prefix 'SNAT'");
                                                                        }
-                                                                       run("$IPTABLES -t nat -A $natchain $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $DPORT $TIME -j $nat --to-source $natip");
+                                                                       run("$IPTABLES -t nat -A $CHAIN_NAT_SOURCE $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $DPORT $TIME -j SNAT --to-source $natip");
                                                                }
                                                                #PROCESS EVERY OTHER RULE (If NOT ICMP, else the rule would be applied double)
                                                                if ($PROT ne '-p ICMP'){
-                                                                       if ($$hash{$key}[17] eq 'ON' && $$hash{$key}[28] ne 'ON'){
+                                                                       if ($LOG && !$NAT) {
                                                                                run("$IPTABLES -A $$hash{$key}[1] $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $DPORT $TIME -j LOG");
                                                                        }
                                                                        run("$IPTABLES -A $$hash{$key}[1] $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $DPORT $TIME -j $$hash{$key}[0]");
                                                                }
                                                                #PROCESS Prot ICMP and type = All ICMP-Types
                                                                if ($PROT eq '-p ICMP' && $$hash{$key}[9] eq 'All ICMP-Types'){
-                                                                       if ($$hash{$key}[17] eq 'ON' && $$hash{$key}[28] ne 'ON'){
+                                                                       if ($LOG && !$NAT) {
                                                                                run("$IPTABLES -A $$hash{$key}[1] $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $DPORT $TIME -j LOG");
                                                                        }
                                                                        run("$IPTABLES -A $$hash{$key}[1] $PROT $STAG $sourcehash{$a}[0] $SPORT -d $targethash{$b}[0] $DPORT $TIME -j $$hash{$key}[0]");
@@ -325,9 +358,6 @@ sub buildrules {
                }
                %sourcehash=();
                %targethash=();
-               undef $TIME;
-               undef $TIMEFROM;
-               undef $TIMETILL;
                undef $fireport;
        }
 }
@@ -340,15 +370,15 @@ sub get_nat_ip {
                $result=$defaultNetworks{$val.'_ADDRESS'};
        }elsif($val eq 'ALL'){
                $result='-i '.$con;
-       }elsif($val eq 'Default IP' && $type eq 'dnat'){
+       }elsif($val eq 'Default IP' && $type eq "DNAT"){
                $result='-d '.$redip;
-       }elsif($val eq 'Default IP' && $type eq 'snat'){
+       }elsif($val eq 'Default IP' && $type eq "SNAT"){
                $result=$redip;
        }else{
                foreach my $al (sort keys %aliases){
-                       if($val eq $al && $type eq 'dnat'){
+                       if($val eq $al && $type eq "DNAT"){
                                $result='-d '.$aliases{$al}{'IPT'};
-                       }elsif($val eq $al && $type eq 'snat'){
+                       }elsif($val eq $al && $type eq "SNAT"){
                                $result=$aliases{$al}{'IPT'};
                        }
                }
@@ -387,7 +417,7 @@ sub utcmin {
 }
 
 sub p2pblock {
-       my $P2PSTRING;
+       my $P2PSTRING = "";
        my $DO;
        open( FILE, "< $p2pfile" ) or die "Unable to read $p2pfile";
        @p2ps = <FILE>;