shorewall_code/Shorewall-common/releasenotes.txt

Shorewall 3.9.7
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                   R E L E A S E  H I G H L I G H T S
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1) This is the first Shorewall release that fully integrates the new
   Shorewall-perl compiler. See the "New Features" section below.

2) You are now offered a choice as to which compiler(s) you install. In
   3.9.2, there are the following packages:

   - Shorewall ( common files )
   - Shorewall-shell ( the shell-based compiler )
   - Shorewall-perl (the Perl-based compiler )

You must install Shorewall and at least one of the compiler packages
(you may install them both).

Problems corrected in 3.9.7.

1)  Several problems relating to exclusion in the hosts file have been
    corrected.

    Symptoms included:

        Access to an undefined value at Rules.pm line 1656.
	Incorrect rule generation.

2)  Specifying 'maclist' in the hosts file's OPTION column now works.

3)  A number of problems with handling the hosts file have been
    corrected. These problems are characterized by Perl run-time
    errors and incorrect rules, including:

    -   Not an ARRAY reference at
        /usr/share/shorewall-perl/Shorewall/Rules.pm line 1420.

    -   -A eth0_fwd -s 192.168.0.0/24-m policy --dir in --pol ipsec -j 
	HASH(0x8345924)->n{name} 

4)  A value of 'detect' in the GATEWAY column of the providers file no
    longer generates an error during [re]start.

5)  The command 'shorewall check -p' resulted in an indefinite loop.

6)  A number of problems having to do with SECTIONs in the rules file
    have been corrected.

7)  The mss zone option now works correctly.

8)  The LOGBURST and LOGLIMIT options in shorewall.conf now work
    correctly

9)  Previously, COMMENT lines could result in invalid iptables-restore
    input being generated. The quote marks around the comment string 
    were being removed during iptables-restore input generation.

Other changes in Shorewall 3.9.7.

1)  Shorewall-perl now validates all IP addresses and addresses ranges
    in rules. DNS names are resolved and an error is issued for any
    name that cannot be resolved.

Migration Considerations:

1)  You cannot simply upgrade your existing Shorewall package. You must
    upgrade Shorewall *and* install one or both of the compilers.

    If you attempt to upgrade using the RPM, you get this result:

    gateway:~ # rpm -Uvh shorewall-3.9.2-1.noarch.rpm 
    error: Failed dependencies:
        shorewall_compiler is needed by shorewall-3.9.2-1.noarch
    gateway:~ #

    You must either:

	rpm -U shorewall-3.9.2.noarch.rpm shorewall-shell-3.9.2.noarch.rpm

    or

	rpm -U shorewall-3.9.2.noarch.rpm shorewall-perl-3.9.2.noarch.rpm
	
    or
	rpm -i shorewall-shell-3.9.2.noarch.rpm
	rpm -U shorewall-3.9.2.noarch.rpm

    or
	rpm -i shorewall-perl-3.9.2.noarch.rpm
	rpm -U shorewall-3.9.2.noarch.rpm

    If you are upgrading using the tarball, you must install either
    shorewall-shell or shorewall-perl before you upgrade
    Shorewall. Otherwise, the install.sh script fails with:

         ERROR: No Shorewall compiler is installed

    The shorewall-shell and shorewall-perl packages are installed from
    the tarball in the expected way; untar the package, and run the
    install.sh script.

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                         N E W  F E A T U R E S
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1)  Shorewall-perl

    This companion product to Shorewall 3.4.2 and later includes a complete
    rewrite of the compiler in Perl.

    I decided to make Shorewall-perl a separate product for several reasons:

    a) Embedded applications are unlikely to adopt Shorewall-perl; even
       Mini-Perl has a substantial disk and Ram footprint.

    b) Because of the gross incompatibilities between the new compiler and the
       old (see below), migration to the new compiler must be voluntary.

    c) By allowing Shorewall-perl to co-exist with the current
       Shorewall stable release (3.4), I'm hoping that the new compiler
       will get more testing and validation than it would if I were to
       package it with a new development version of Shorewall itself.

    d) Along the same vein, I think that users will be more likely to
       experiment with the new compiler if they can easily fall back to
       the old one if things get sticky.
    ------------------------------------------------------------------------
                      T H E   G O O D   N E W S:
    ------------------------------------------------------------------------
    a) The compiler has a small disk footprint.
    b) The compiler is very fast.
    c) The compiler generates a firewall script that uses iptables-restore;
       so the script is very fast.
    d) Use of the perl compiler is optional! The old slow clunky
       Bourne-shell compiler is still available.
    ------------------------------------------------------------------------
                      T H E   B A D   N E W S:
    ------------------------------------------------------------------------
    There are a number of incompatibilities between the Perl-based compiler
    and the Bourne-shell one. Some of these will probably go away by first
    official release but most will not.

    a) The Perl-based compiler requires the following capabilities in your
       kernel and iptables.

       - addrtype match (may be relaxed later)
       - multiport match (will not be relaxed)

       These capabilities are in current distributions.

    b) Now that Netfilter has features to deal reasonably with port lists,
       I see no reason to duplicate those features in Shorewall. The
       Bourne-shell compiler goes to great pain (in some cases) to
       break very long port lists ( > 15 where port ranges in lists count
       as two ports) into individual rules. In the new compiler, I'm
       avoiding the ugliness required to do that. The new compiler just
       generates an error if your list is too long. It will also produce
       an error if you insert a port range into a port list and you don't
       have extended multiport support.

    c) BRIDGING=Yes is not supported. The kernel code necessary to
       support this option was removed in Linux kernel 2.6.20.

    d) The BROADCAST column in the interfaces file is essentially unused;
       if you enter anything in this column but '-' or 'detect', you will
       receive a warning. This will be relaxed if and when the addrtype
       match requirement is relaxed.

    e) Because the compiler is now written in Perl, your compile-time
       extension scripts from earlier versions will no longer work.
       Compile-time extension scripts are executed using the Perl
       'eval `cat <file>`' mechanism. Be sure that each script returns a
       'true' value; otherwise, the compiler will assume that the script
       failed and will abort the compilation.

       When a script is invoked, the $chainref scalar variable will hold a
       reference to a chain table entry. 

           $chainref->{name}  contains the name of the chain
           $chainref->{table} holds the table name
       
           To add a rule to the chain:

	      add_rule $chainref, <the rule>

           Where

              <the rule> is a scalar argument holding the rule text. Do
              not include "-A <chain name>"

           Example:

              add_rule $chainref, '-j ACCEPT';

           To insert a rule into the chain:

              insert_rule $chainref, <rulenum>, <the rule>

           The log_rule_limit function works like it does in the shell
           compiler with two exceptions:

              - You pass the chain reference rather than the name of
                the chain.
	      - The commands are 'add' and 'insert' rather than '-A'
                and '-I'.
	      - There is only a single "pass as-is to iptables"
                argument (so you must quote that part).

           Example:

	      log_rule_limit
	          'info' , 
	          $chainref , 
	          $chainref->{name},
	          'DROP' , 
	          '',    #Limit
	          '' ,   #Log tag
	          'add';	      

    f) The 'refresh' command is now synonymous with 'restart'.

    g) Some run-time scripts will need to be changed to write their
       iptables commands to file descriptor 3 in iptables-restore
       format rather than running those commands.

	    maclog

       Details to follow.

       Some run-time scripts are simply eliminated because they no
       longer make any sense under Shorewall-perl:

	initdone  - The these two scripts assumed a model where the
	continue    chains were built in parallel. In the
		    iptables-restore model, chains are built serially
		    within tables and tables are build serially.  

	refresh   - The 'refresh' command is the same as 'restart'
	refreshed

    h) The /etc/shorewall/tos file now has zone-independent SOURCE and
       DEST columns as do all other files except the rules and policy
       files.

       The SOURCE column may be one of the following:

           [all:]<address>[,...]
           [all:]<interface>[:<address>[,...]]
           $FW[:<address>[,...]]

       The DEST column may be one of the following:
       
           [all:]<address>[,...]
           [all:]<interface>[:<address>[,...]]

       This is a permanent change. The old zone-based rules have never
       worked right and this is a good time to replace them. I've tried
       to make the new syntax cover the most common cases without
       requiring change to existing files. In particular, it will
       handle the tos file released with Shorewall 1.4 and earlier.

    i) Shorewall is now out of the ipset load/reload business. With
       scripts generated by the Perl-based Compiler, the Netfilter
       ruleset is never cleared. That means that there is no
       opportunity for Shorewall to load/reload your ipsets since that
       cannot be done while there are any current rules using ipsets.

       So:

	i)   Your ipsets must be loaded before Shorewall starts. You
	     are free to try to do that with the following code in
	     /etc/shorewall/start:

	     if [ "$COMMAND" = start ]; then
		ipset -U :all: :all:
		ipset -F
		ipset -X
		ipset -R < /my/ipset/contents
	     fi

	     The file '/my/ipset/contents' (not its real name of
	     course) will normally be produced using the ipset -S
	     command.

	     The above will work most of the time but will fail in a
	     'shorewall stop' - 'shorewall start' sequence if you
	     use ipsets in your routestopped file (see below).

	ii)  Your ipsets may not be reloaded until Shorewall is stopped
	     or cleared.

	iii) If you specify ipsets in your routestopped file then
	     Shorewall must be cleared in order to reload your ipsets.

       As a consequence, scripts generated by the Perl-based compiler
       will ignore /etc/shorewall/ipsets and will issue a warning if
       you set SAVE_IPSETS=Yes in shorewall.conf.

    j) Because the configuration files (with the exception of
       /etc/shorewall/params) are now processed by the Perl-based
       compiler rather than by the shell, only the basic forms of Shell
       expansion ($variable and ${variable}) are supported. The more
       exotic forms such as ${variable:=default} are not
       supported. Both variables defined in /etc/shorewall/params and
       environmental variables (exported by the shell) can be used in
       configuration files.

    h) USE_ACTIONS=No is not supported. That option is intended to
       minimize Shorewall's footprint in embedded applications. As a
       consequence, Default Macros are not supported.

    i) DELAYBLACKLISTLOAD=Yes is not supported. The entire ruleset is
       atomically loaded with one execution of iptables-restore.

    j) MAPOLDACTIONS=Yes is not supported. People should have converted
    to using macros by now.

    k) The pre Shorewall-3.0 format of the zones file is not supported;
       neither is the /etc/shorewall/ipsec file.

    l) BLACKLISTNEWONLY=No is not permitted with FASTACCEPT=Yes. This
       combination doesn't work in previous versions of Shorewall so
       the Perl-based compiler simply rejects it.

    m) Shorewall-perl has a single rule generator that is used for all
       rule-oriented files. So it is important that the syntax is
       consistent between files.
       
       With shorewall-shell, there is a special syntax in the SOURCE
       column of /etc/shorewall/masq to designate "all traffic entering
       the firewall on this interface except...".

       Example:

       #INTERFACE	SOURCE			ADDRESSES
       eth0		eth1!192.168.4.9	...

       Shorewall-perl uses syntax that is consistent with the rest of
       Shorewall:

       #INTERFACE	SOURCE			ADDRESSES
       eth0		eth1:!192.168.4.9	...

2)  An 'optional' option has been added to
    /etc/shorewall/interfaces. When 'optional' is specified for an
    interface, Shorewall will be silent when:

    - a /proc/sys/net/ipv4/conf/ entry for the interface cannot be
      modified (including for proxy ARP).

    - The first address of the interface cannot be obtained.

    I specify 'optional' on interfaces to Xen virtual machines that may
    or may not be running when Shorewall is [re]started.

    CAUTION: Use 'optional' at your own risk. If you [re]start
    Shorewall when an 'optional' interface is not available and then do
    a 'shorewall save', subsequent 'shorewall restore' and 'shorewall -f
    start' operations will instantiate a ruleset that does not support
    that interface, even if it is available at the time of the
    restore/start.

3)  The treatment of the following interface options has changed under
    Shorewall-perl.

    -	arp_filter
    -	routefilter
    -   logmartians
    -	proxy_arp
    -	sourceroute

    With the Shorewall-shell compiler, Shorewall resets these options
    on all interfaces then sets the option on those interfaces
    for which the option is defined in /etc/shorewall/interfaces.

    Under Shorewall-perl, these options can be specified with the value
    0 or 1 (e.g., proxy_arp=0). If no value is specified, the value 1
    is assumed. Shorewall will modify only the setting of those
    interfaces for which the option is specified and will set the
    option to the given value.

    A fatal compilation error is also generated if you specify one of
    these options with a wildcard interface (one ending with '+').

4)  Thanks to Paul Gear, an IPPServer macro has been added. Be sure to
    read the comments in the macro file before trying to use this
    macro.

5)  The LOG_MARTIANS and ROUTE_FILTER options are now tri-valued.

	Yes -  Same as before
	No  -  Same as before except that it applies regardless of
	       whether any interfaces have the logmartians/routefilter
	       option
	Keep - Shorewall ignores the option entirely.

6)  Eariler generations of Shorewall Lite required that remote root
    login via ssh be enabled in order to use the 'load' and 'reload'
    commands.

    Beginning with this release, you may define an alternative means
    for accessing the remote firewall system.

    Two new options have been added to shorewall.conf:

	RSH_COMMAND
	RCP_COMMAND

    The default values for these are as follows:

	RSH_COMMAND: ssh ${root}@${system} ${command}
	RCP_COMMAND: scp ${files} ${root}@${system}:${destination}

    Shell variables that will be set when the commands are envoked are
    as follows:

       root  - root user. Normally 'root' but may be overridden using
               the '-r' option.

       system - The name/IP address of the remote firewall system.

       command - For RSH_COMMAND, the command to be executed on the 
                 firewall system.

       files   - For RCP_COMMAND, a space-separated list of files to
                 be copied to the remote firewall system.

       destination - The directory on the remote system that the files 
                     are to be copied into. 

7)  The accounting, masq, rules and tos files now have a 'MARK' column
    similar to the column of the same name in the tcrules file. This
    column allows filtering by MARK and CONNMARK value.

8)  SOURCE and DEST are now reserved zone names to avoid problems with
    bi-directional macro definitions which use these as names as key
    words.

----------------------------------------------------------------------------
                      P R E R E Q U I S I T E S
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- Perl (I use Perl 5.8.8 but other versions should work fine)
- Perl Cwd Module
- Perl File::Basename Module
- Perl File::Temp Module
----------------------------------------------------------------------------
               U S I N G   T H E   N E W   C O M P I L E R
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If you only install one compiler, then that compiler will be used.

If you install both compilers, then the compiler actually used depends
on the SHOREWALL_COMPILER setting in shorewall.conf.

The value of this new option can be either 'perl' or 'shell'.

If you add 'SHOREWALL_COMPILER=perl' to /etc/shorewall/shorewall.conf
then by default, the new compiler will be used on the system. If you
add it to shorewall.conf in a separate directory (such as a
Shorewall-lite export directory) then the new compiler will only be
used when you compile from that directory.

If you only install one compiler, it is suggested that you do not set
SHOREWALL_COMPILER.

If you install Shorewall-perl under Shorewall 3.9.2 or later, you can
select the compiler to use on the command line using the 'C option:

       '-C shell' means use the shell compiler
       '-C perl' means use the perl compiler

The -C option overrides the setting in shorewall.conf. 

Example:

	shorewall restart -C perl

Regardless of the setting of SHOREWALL_COMPILER, there is one change in
Shorewall operation that is triggered simply by installing
shorewall-perl. Your params file will be processed during compilation 
with the shell's '-a' option  which causes any variables that you set
or create in that file to be automatically exported. Since the params
file is processed before shorewall.conf, using -a insures that the
settings of your params variables are available to the new compiler
should its use be specified in shorewall.conf.