Shorewall 2.0.2b ---------------------------------------------------------------------- Problems Corrected since 2.0.1 1) The /etc/init.d/shorewall script installed on Debian by install.sh failed silently due to a missing file (/usr/share/shorewall/wait4ifup). That file is not part of the normal Shorewall distribution and is provided by the Debian maintainer. 2) A meaningless warning message out of the proxyarp file processing has been eliminated. 3) The "shorewall delete" command now correctly removes all dynamic rules pertaining to the host(s) being deleted. Thanks to Stefan Engel for this correction. Problems Corrected since 2.0.2 1) The 'firewall' script is not purging temporary restore files in /var/lib/shorewall. These files have names of the form "restore-nnnnn". 2) The /var/lib/shorewall/restore script did not load the kernel modules specified in /etc/shorewall/modules. 3) Specifying a null common action in /etc/shorewall/actions (e.g., :REJECT) results in a startup error. 4) If /var/lib/shorewall does not exist, shorewall start fails. 5) DNAT rules with a dynamic source zone don't work properly. When used, these rules cause the rule to be checked against ALL input, not just input from the designated zone. ----------------------------------------------------------------------- Issues when migrating from Shorewall 2.0.1 to Shorewall 2.0.2: 1) Extension Scripts In order for extension scripts to work properly with the new iptables-save/restore integration (see New Feature 1 below), some change may be required to your extension scripts. If your extension scripts are executing commands other than iptables then those commands must also be written to the restore file (a temporary file in /var/lib/shorewall that is renamed /var/lib/shorewall/restore-base at the end of the operation). The following functions should be of help: A. save_command() -- saves the passed command to the restore file. Example: save_command echo Operation Complete That command would simply write "echo Operation Complete" to the restore file. B. run_and_save_command() -- saves the passed command to the restore file then executes it. The return value is the exit status of the command. Example: run_and_save_command "echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all" Note that as in this example, when the command involves file redirection then the entire command must be enclosed in quotes. This applies to all of the functions described here. C. ensure_and_save_command() -- runs the passed command. If the command fails, the firewall is restored to it's prior saved state and the operation is terminated. If the command succeeds, the command is written to the restore file. 2) Dynamic Zone support. If you don't need to use the "shorewall add" and "shorewall delete" commands, you should set DYNAMIC_ZONES=No in /etc/shorewall/shorewall.conf. New Features: 1) Shorewall has now been integrated with iptables-save/iptables-restore to provide very fast start and restart. The elements of this integration are as follows: a) The 'shorewall save' command now saves the current configuration in addition to the current dynamic blacklist. If you have dynamic zones, you will want to issue 'shorewall save' when the zones are empty or the current contents of the zones will be restored by the 'shorewall restore' and 'shorewall -f start' commands. b) The 'shorewall restore' command has been added. This command restores the configuration at the time of the last 'save'. c) The -f (fast) option has been added to 'shorewall start'. When specified (e.g. 'shorewall -f start'), shorewall will perform a 'shorewall restore' if there is a saved configuration. If there is no saved configuration, a normal 'shorewall start' is performed. d) The /etc/init.d/shorewall script now translates the 'start' command into 'shorewall -f start' so that fast restart is possible. e) When a state-changing command encounters an error and there is a current saved configuration, that configuration will be restored (currently, the firewall is placed in the 'stopped' state). f) If you have previously saved the running configuration and want Shorewall to discard it, use the 'shorewall forget' command. WARNING: iptables 1.2.9 is broken with respect to iptables-save; If your kernel has connection tracking match support, you must patch iptables 1.2.9 with the iptables patch availale from the Shorewall errata page. 2) The previous implementation of dynamic zones was difficult to maintain. I have changed the code to make dynamic zones optional under the control of the DYNAMIC_ZONES option in /etc/shorewall/shorewall.conf. 3) In earlier Shorewall 2.0 releases, Shorewall searches in order the following directories for configuration files. a) The directory specified in a 'try' command or specified using the -c option. b) /etc/shorewall c) /usr/share/shorewall In this release, the CONFIG_PATH option is added to shorewall.conf. CONFIG_PATH contains a list of directory names separated by colons (":"). If not set or set to a null value (e.g., CONFIG_PATH="") then "CONFIG_PATH=/etc/shorewall:/usr/share/shorewall" is assumed. Now Shorewall searches for shorewall.conf according to the old rules and for other configuration files as follows: a) The directory specified in a 'try' command or specified using the -c option. b) Each directory in $CONFIG_PATH is searched in sequence. In case it is not obvious, your CONFIG_PATH should include /usr/share/shorewall and your shorewall.conf file must be in the directory specified via -c or in a try command, in /etc/shorewall or in /usr/share/shorewall. For distribution packagers, the default CONFIG_PATH is set in /usr/share/shorewall/configpath. You can customize this file to have a default that differs from mine. 4) Previously, in /etc/shorewall/nat a Yes (or yes) in the LOCAL column would only take effect if the ALL INTERFACES column also contained Yes or yes. Now, the LOCAL columns contents are treated independently of the contents of the ALL INTERFACES column. 5) The folks at Mandrake have created yet another kernel module naming convention (module names end in "ko.gz"). As a consequence, beginning with this release, if MODULE_SUFFIX isn't specified in shorewall.conf, then the default value is "o gz ko o.gz ko.gz". 6) An updated bogons file is included in this release. 7) In /etc/shorewall/rules and in action files generated from /usr/share/shorewall/action.template, rules that perform logging can specify an optional "log tag". A log tag is a string of alphanumeric characters and is specified by following the log level with ":" and the log tag. Example: ACCEPT:info:ftp net dmz tcp 21 The log tag is appended to the log prefix generated by the LOGPREFIX variable in /etc/shorewall/conf. If "ACCEPT:info" generates the log prefix "Shorewall:net2dmz:ACCEPT:" then "ACCEPT:info:ftp" will generate "Shorewall:net2dmz:ACCEPT:ftp " (note the trailing blank). The maximum length of a log prefix supported by iptables is 29 characters; if a larger prefix is generated, Shorewall will issue a warning message and will truncate the prefix to 29 characters. 8) A new "-q" option has been added to /sbin/shorewall commands. It causes the start, restart, check and refresh commands to produce much less output so that warning messages are more visible (when testing this change, I discovered a bug where a bogus warning message was being generated). 9) Shorewall now uses 'modprobe' to load kernel modules if that utility is available in the PATH; otherwise, 'insmod' is used. 10) It is now possible to restrict entries in the /etc/shorewall/masq file to particular protocols and destination port(s). Two new columns (PROTO and PORT(S)) have been added to the file. Example: You want all outgoing SMTP traffic entering the firewall on eth1 to be sent from eth0 with source IP address 206.124.146.177. You want all other outgoing traffic from eth1 to be sent from eth0 with source IP address 206.124.146.176. eth0 eth1 206.124.146.177 tcp 25 eth0 eth1 206.124.146.176 THE ORDER OF THE ABOVE TWO RULES IS SIGNIFICANT!!!!! Assuming that 10.0.0.0/8 is the only host/network connected to eth1, the progress message at "shorewall start" would be: Masqueraded Networks and Hosts: To 0.0.0.0/0 (tcp 25) from 10.0.0.0/8 through eth0 using 206.124.146.177 To 0.0.0.0/0 (all) from 10.0.0.0/8 through eth0 using 206.124.146.176 11) Two new actions are available in the /etc/shorewall/rules file. ACCEPT+ -- Behaves like ACCEPT with the exception that it exempts matching connections from subsequent DNAT[-] and REDIRECT[-] rules. NONAT -- Exempts matching connections from subsequent DNAT[-] and REDIRECT[-] rules. 12) A new extension script 'initdone' has been added. This script is invoked at the same point as the 'common' script was previously and is useful for users who mis-used that script under Shorewall 1.x (the script was intended for adding rules to the 'common' chain but many users treated it as a script for adding rules before Shorewall's). 13) Installing/Upgrading Shorewall on Slackware has been improved. Slackware users must use the tarball and must modify settings in the install.sh script before running it as follows: DEST="/etc/rc.d" INIT="rc.firewall" Thanks to Alex Wilms for helping with this change.