mirror of
https://gitlab.com/shorewall/code.git
synced 2024-11-15 20:24:09 +01:00
4beb3a6cee
git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@5905 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb
279 lines
11 KiB
Plaintext
279 lines
11 KiB
Plaintext
----------------------------------------------------------------------------
|
|
Shorewall-perl 3.9.1
|
|
|
|
These release notes apply if you are installing Shorewall-perl under
|
|
Shorewall 3.4.2 or later. If you are installing Shorewall 3.9.x, please
|
|
see the release notes in the Shorewall package.
|
|
----------------------------------------------------------------------------
|
|
This companion product to Shorewall 3.4.2 and later includes a complete
|
|
rewrite of the compiler in Perl.
|
|
|
|
Shorewall-perl depends on Shorewall (3.4.2 or later). So if you want to use the
|
|
new compiler, you must install both Shorewall and Shorewall-perl.
|
|
|
|
Even if you install Shorewall-perl, you have a choice of which compiler you use.
|
|
The choice is specified in the shorewall.conf file so you can select the
|
|
compiler to use on a system-by-system basis when running Shorewall Lite on
|
|
remote systems.
|
|
|
|
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 only 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 (I know that it has been handy for me ;-) )
|
|
----------------------------------------------------------------------------
|
|
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) The 'maclog' extension script will need to be changed to write its
|
|
iptables commands to file descriptor 3 in iptables-restore format
|
|
rather than running those commands.
|
|
|
|
maclog
|
|
|
|
You can use this syntax:
|
|
|
|
echo -A $CHAIN <rest of rule> >&3
|
|
|
|
Example:
|
|
|
|
echo -A $CHAIN -p icmp -j RETURN >&3
|
|
|
|
You may not insert a rule into the chain -- you may only add rules.
|
|
|
|
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>[,...]]
|
|
$FW[:<address>[,...]]
|
|
|
|
The DEST column may be one of the following:
|
|
[all:]<address>[,...]
|
|
[all:]<interface>[:<address>[,...]]
|
|
|
|
This is a permanent change. The old zone-based rules have never
|
|
worked right and this is a good time to replace them. I've tried to
|
|
make the new syntax cover the most common cases without requiring
|
|
change to existing files. In particular, it will handle the tos file
|
|
released with Shorewall 1.4 and earlier.
|
|
|
|
i) Currently, support for ipsets is untested. That will change with
|
|
future pre-releases but one thing is certain -- Shorewall is now out
|
|
of the ipset load/reload business. With scripts generated by the
|
|
Perl-based Compiler, the Netfilter ruleset is never cleared. That
|
|
means that there is no opportunity for Shorewall to load/reload your
|
|
ipsets since that cannot be done while there are any current rules
|
|
using ipsets.
|
|
|
|
So:
|
|
i) Your ipsets must be loaded before Shorewall starts. You
|
|
are free to try to do that with the following code in
|
|
/etc/shorewall/start:
|
|
|
|
if [ "$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.
|
|
----------------------------------------------------------------------------
|
|
P R E R E Q U I S I T E S
|
|
----------------------------------------------------------------------------
|
|
In addition to Shorewall-3.4.2 or later, you need:
|
|
|
|
- Perl (I use Perl 5.8.8 but other versions should work fine)
|
|
- Perl Cwd Module
|
|
- Perl File::Basename Module
|
|
- Perl File::Temp Module
|
|
----------------------------------------------------------------------------
|
|
I N S T A L L A T I O N
|
|
----------------------------------------------------------------------------
|
|
Either
|
|
|
|
$ tar -jxf shorewall-perl-3.9.1.tar.bz2
|
|
$ cd shorewall-perl-3.9.1
|
|
$ ./install.sh
|
|
|
|
or
|
|
|
|
$ rpm -ivh shoreawll-pl-3.9.1-1.noarch.rpm
|
|
----------------------------------------------------------------------------
|
|
U S I N G T H E N E W C O M P I L E R
|
|
----------------------------------------------------------------------------
|
|
By default, the old Bourne-shell based compiler will be used.
|
|
|
|
To use the new compiler, add this to shorewall.conf:
|
|
|
|
SHOREWALL_COMPILER=perl
|
|
|
|
If you add this setting 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.
|
|
|
|
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 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 it's use be
|
|
specified in shorewall.conf.
|
|
|