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shorewall_code/Shorewall/releasenotes.txt
teastep 47c914a86b Fix multiple 'drop/reject' bug 
git-svn-id: https://shorewall.svn.sourceforge.net/svnroot/shorewall/trunk@727 fbd18981-670d-0410-9b5c-8dc0c1a9a2bb
2003-08-24 15:36:13 +00:00

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This is a minor release of Shorewall.
Problems Corrected since version 1.4.6:
1) Corrected problem in 1.4.6 where the MANGLE_ENABLED variable was
being tested before it was set.
2) Corrected handling of MAC addresses in the SOURCE column of the
tcrules file. Previously, these addresses resulted in an invalid
iptables command.
3) The "shorewall stop" command is now disabled when
/etc/shorewall/startup_disabled exists. This prevents people from
shooting themselves in the foot prior to having configured
Shorewall.
4) A change introduced in version 1.4.6 caused error messages during
"shorewall [re]start" when ADD_IP_ALIASES=Yes and ip addresses were
being added to a PPP interface; the addresses were successfully
added in spite of the messages.
The firewall script has been modified to eliminate the error
messages.
5) Interface-specific dynamic blacklisting chains are now displayed by
"shorewall monitor" on the "Dynamic Chains" page (previously named
"Dynamic Chain").
6) Thanks to Henry Yang, LOGRATE and LOGBURST now work again.
7) The 'shorewall reject' and 'shorewall drop' commands now delete any
existing rules for the subject IP address before adding a new DROP
or REJECT rule. Previously, there could be many rules for the same
IP address in the dynamic chain so that multiple 'allow' commands
were required to re-enable traffic to/from the address.
Migration Issues:
1) IP Traffic Accounting is changed from Snapshot 20030813.
2) The Uset Set capability introduced in SnapShot 20030821 has
changed -- see the User Set page for details.
3) The per-interface dynamic blacklisting facility from previous 1.4.6
Snapshots has been removed. The implications of the facility for
users with dial-up internet connections were too complicated to
document adaquately. My apologies for unleashing this half-baked
idea on the user base.
New Features:
1) The 2.6 series of Linux kernels will not support the 'unclean'
match extension except in Patch-O-Matic. In keeping with the
Shorewall policy of not supporting netfilter extensions that are
only available in Patch-O-Matic, the 'dropunclean' and
'logunclean' interface options will be removed in a future
release. In the 1.4.7 release, they are flagged with a warning.
2) Thanks to Steve Herber, the help command can now give
command-specific help.
3) A new option "ADMINISABSENTMINDED" has been added to
/etc/shorewall/shorewall.conf. This option has a default value of
"No" for existing Shorewall users who are upgrading to this release.
With this setting, Shorewall's 'stopped' state continues as it has
been; namely, in the stopped state only traffic to/from hosts listed
in /etc/shorewall/routestopped is accepted.
The default for new users installing Shorewall for the first time is
ADMINISABSENTMINDED=Yes.With that setting, in addition to traffic
to/from the hosts listed in /etc/shorewall/routestopped, Shorewall
will allow:
a) All traffic originating from the firewall itself; and
b) All traffic that is part of or related to an already-existing
connection.
In particular, with ADMINISABSENTMINDED=Yes, a "shorewall stop"
entered through an ssh session will not kill the session.
Note though that it is still possible for people to shoot themselves
in the foot.
Example:
/etc/shorewall/nat:
206.124.146.178 eth0:0 192.168.1.5
/etc/shorewall/rules:
ACCEPT net loc:192.168.1.5 tcp 22
ACCEPT loc fw tcp 22
I ssh into 206.124.146.178 which establishes an SSH connection with
192.168.1.5. I then create a second SSH connection from that
computer to the firewall and confidently type "shorewall
stop". As part of stopping, Shorewall removes eth0:0 which kills my
SSH connection to 192.168.1.5!!!
4) Given the wide range of VPN software, I can never hope to add
specific support for all of it. I have therefore decided to add
"generic" tunnel support.
Generic tunnels work pretty much like any of the other tunnel
types. You usually add a zone to represent the systems at the other
end of the tunnel and you add the appropriate rules/policies to
implement your security policy regarding traffic to/from those
systems.
In the /etc/shorewall/tunnels file, you can have entries of the
form:
# TYPE ZONE GATEWAY GATEWAY ZONE
generic:<protocol>[:<port>] <zone> <ip address> <gateway zones>
where:
<protocol> is the protocol used by the tunnel
<port> if the protocol is 'udp' or 'tcp' then this
is the destination port number used by the
tunnel.
<zone> is the zone of the remote tunnel gateway
<ip address> is the IP address of the remote tunnel
gateway.
<gateway zone> Optional. A comma-separated list of zone names.
If specified, the remote gateway is to be
considered part of these zones.
5) An 'arp_filter' option has been added to the
/etc/shorewall/interfaces file. This option causes
/proc/sys/net/ipv4/conf/<interface>/arp_filter to be set with the
result that this interface will only answer ARP 'who-has' requests
from hosts that are routed out of that interface. Setting this
option facilitates testing of your firewall where multiple firewall
interfaces are connected to the same HUB/Switch (all interfaces
connected to the single HUB/Switch should have this option
specified). Note that using such a configuration in a production
environment is strongly recommended against.
6) The ADDRESS column in /etc/shorewall/masq may now include a
comma-separated list of addresses and/or address ranges. Netfilter
will use all listed addresses/ranges in round-robin fashion.
7) An /etc/shorewall/accounting file has been added to allow for
traffic accounting..
The accounting rules are placed in a chain called "accounting" and
can thus be displayed using "shorewall show accounting".
The file has the following columns:
ACTION - What to do when a match is found. Possible
values are:
COUNT - Simply count the match and continue
trying to match the packet with the
following accounting rules.
DONE - Count the match and don't attempt to
match any following accounting rules.
<chain> - The name of a chain to jump to.
Shorewall will create the chain
automatically. If the name of the
chain is followed by ":COUNT" then
a COUNT rule matching this rule
will automatically be added to
<chain>
CHAIN - The name of the chain where the accounting
rule is to be added. If empty or "-" then
the "accounting" chain is assumed.
SOURCE - Packet Source
The name of an interface, an address (host or
net) or an interface name followed by ":"
and a host or net address.
DESTINATION - Packet Destination
Format the same as the SOURCE column.
PROTOCOL A protocol name (from /etc/protocols), a
protocol number.
DEST PORT Destination Port number
Service name from /etc/services or port
number. May only be specified if the protocol
is TCP or UDP (6 or 17).
SOURCE PORT Source Port number
Service name from /etc/services or port
number. May only be specified if the protocol
is TCP or UDP (6 or 17).
In all columns except ACTION and CHAIN, the values "-","any" and
"all" are treated as wild-cards.
The accounting rules are evaluated in the Netfilter 'filter'
table. This is the same environment where the 'rules' file rules are
evaluated and in this environment, DNAT has already occurred in
inbound packets and SNAT has not yet occurred on outbound ones.
The accounting rules are placed in a chain called "accounting" and
can thus be displayed using "shorewall show accounting".
See http://shorewall.net/Accounting.html for examples.
8) Bridge interfaces (br[0-9]) may now be used in /etc/shorewall/maclist.
9) ACCEPT, DNAT[-], REDIRECT[-] and LOG rules defined in
/etc/shorewall/rules may now be rate-limited. For DNAT and
REDIRECT rules, rate limiting occurs in the nat table DNAT rule; the
corresponding ACCEPT rule in the filter table is not rate
limited. If you want to limit the filter table rule, you will need
to create two rules; a DNAT- rule and an ACCEPT rule which can be
rate-limited separately.
To specify a rate limit, you can follow one of two approaches:
a) You may follow ACCEPT, DNAT[-], REDIRECT[-] or LOG with
< <rate>/<interval>[:<burst>] >
where
<rate> is the sustained rate per <interval>
<interval> is "sec" or "min"
<burst> is the largest burst accepted within an
<interval>. If not given, the default of 5 is
assumed.
There may be no white space between the ACTION and "<" nor there
may be any white space within the burst specification. If you want
to specify logging of a rate-limited rule, the ":" and log level
comes after the ">" (e.g., ACCEPT<2/sec:4>:info ).
b) There is a new RATE LIMIT column at the far right of the
file (beyond column 80). You may place the rate limit there in
the format:
<rate>/<interval>[:<burst>]
where <rate>, <interval> and <burst> are as above.
You may not place a rate limit in both the ACTION and RATE LIMIT
columns.
Let's take an example:
ACCEPT<2/sec:4> net dmz tcp 80
The first time this rule is reached, the packet will be accepted; in
fact, since the burst is 4, the first four packets will be
accepted. After this, it will be 500ms (1 second divided by the rate
of 2) before a packet will be accepted from this rule, regardless of
how many packets reach it. Also, every 500ms which passes without
matching a packet, one of the bursts will be regained; if no packets
hit the rule for 2 second, the burst will be fully recharged;
back where we started.
Warning: When rate limiting is specified on a rule with "all" in the
SOURCE or DEST fields, the limit will apply to each pair of
zones individually rather than as a single limit for all pairs of
zones covered by the rule.
10) Multiple chains may now be displayed in one "shorewall show"
command (e.g., shorewall show INPUT FORWARD OUTPUT).
11) Output rules (those with $FW as the SOURCE) may now be limited to
a set of local users and/or groups. See
http://shorewall.net/UserSets.html for details.
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