Name

policy — Shorewall policy file

Synopsis

/etc/shorewall/policy

Description

This file defines the high-level policy for connections between zones defined in shorewall-zones(5).

Important

The order of entries in this file is important

This file determines what to do with a new connection request if we don't get a match from the /etc/shorewall/rules file . For each source/destination pair, the file is processed in order until a match is found ("all" will match any client or server).

Important

Intra-zone policies are pre-defined

For $FW and for all of the zones defined in /etc/shorewall/zones, the POLICY for connections from the zone to itself is ACCEPT (with no logging or TCP connection rate limiting but may be overridden by an entry in this file. The overriding entry must be explicit (cannot use "all" in the SOURCE or DEST).

Similarly, if you have IMPLICIT_CONTINUE=Yes in shorewall.conf, then the implicit policy to/from any sub-zone is CONTINUE. These implicit CONTINUE policies may also be overridden by an explicit entry in this file.

The columns in the file are as follows.

SOURCE - zone|$FW|all

Source zone. Must be the name of a zone defined in shorewall-zones(5), $FW or "all".

DEST - zone|$FW|all

Destination zone. Must be the name of a zone defined in shorewall-zones(5), $FW or "all". If the DEST is a bport zone, then the SOURCE must be "all", another bport zone associated with the same bridge, or it must be an ipv4 zone that is associated with only the same bridge.

POLICY - {ACCEPT|DROP|REJECT|CONTINUE|QUEUE|NFQUEUE[(queuenumber)]|NONE}[:{default-action-or-macro|None}]

Policy if no match from the rules file is found.

If the policy is other than CONTINUE or NONE then the policy may be followed by ":" and one of the following:

  1. The word "None" or "none". This causes any default action defined in shorewall.conf(5) to be omitted for this policy.

  2. The name of an action (requires that USE_ACTIONS=Yes in shorewall.conf(5)). That action will be invoked before the policy is enforced.

  3. The name of a macro. The rules in that macro will be applied before the policy is enforced. This does not require USE_ACTIONS=Yes.

Possible policies are:
ACCEPT
Accept the connection.
DROP
Ignore the connection request.
REJECT
For TCP, send RST. For all other, send an "unreachable"
                ICMP.
QUEUE
Queue the request for a user-space application such as
                Snort-inline.
NFQUEUE
Queue the request for a user-space application using the
                nfnetlink_queue mechanism. If a
                queuenumber is not given, queue
                zero (0) is assumed.
CONTINUE
Pass the connection request past any other rules that it
                might also match (where the source or destination zone in
                those rules is a superset of the SOURCE or DEST in this
                policy). See shorewall-nesting(5) for
                additional information.
NONE
Assume that there will never be any packets from this
                SOURCE to this DEST. Shorewall will not create any
                infrastructure to handle such packets and you may not have any
                rules with this SOURCE and DEST in the /etc/shorewall/rules
                file. If such a packet is
                received, the result is undefined. NONE may not be used if the
                SOURCE or DEST columns contain the firewall zone ($FW) or
                "all".
LOG LEVEL (Optional) -
        [log-level|ULOG|NFLOG]
If supplied, each connection handled under the default POLICY
          is logged at that level. If not supplied, no log message is
          generated. See syslog.conf(5) for a description of log
          levels.
You may also specify ULOG or NFLOG (must be in upper case).
          This will log to the ULOG or NFLOG target and will send to a
          separate log through use of ulogd (http://www.netfilter.org/projects/ulogd/index.html).
If you don't want to log but need to specify the following
          column, place "-" here.
BURST:LIMIT -
        [{s|d}:[[name]:]]]rate/{second|minute}[:burst]
If passed, specifies the maximum TCP connection
          rate and the size of an acceptable
          burst. If not specified, TCP connections are
          not limited. If the burst parameter is
          omitted, a value of 5 is assumed.
When s: or d: is specified,
          the rate applies per source IP address or per destination IP address
          respectively. The name may be chosen by
          the user and specifies a hash table to be used to count matching
          connections. If not give, the name shorewall is assumed. Where more than one
          POLICY specifies the same name, the connections counts for the
          policies are aggregated and the individual rates apply to the
          aggregated count.
CONNLIMIT -
        limit[:mask]
May be used to limit the number of simultaneous connections
          from each individual host to limit
          connections. While the limit is only checked on connections to which
          this policy could apply, the number of current connections is
          calculated over all current connections from the SOURCE host. By
          default, the limit is applied to each host individually but can be
          made to apply to networks of hosts by specifying a
          mask. The mask
          specifies the width of a VLSM mask to be applied to the source
          address; the number of current connections is then taken over all
          hosts in the subnet
          source-address/mask.
Example
  1. All connections from the local network to the internet are
        allowed
  2. All connections from the internet are ignored but logged at
        syslog level KERNEL.INFO.
  3. All other connection requests are rejected and logged at level
        KERNEL.INFO.
        #SOURCE         DEST            POLICY          LOG           BURST:LIMIT
        #                                               LEVEL
        loc             net             ACCEPT
        net             all             DROP            info
        #
        # THE FOLLOWING POLICY MUST BE LAST
        #
        all             all             REJECT          info
FILES
/etc/shorewall/policy
See ALSO
shorewall(8), shorewall-accounting(5), shorewall-actions(5),
    shorewall-blacklist(5), shorewall-hosts(5), shorewall-interfaces(5),
    shorewall-ipsec(5), shorewall-maclist(5), shorewall-masq(5),
    shorewall-nat(5), shorewall-netmap(5), shorewall-params(5),
    shorewall-policy(5), shorewall-providers(5), shorewall-proxyarp(5),
    shorewall-route_rules(5), shorewall-routestopped(5), shorewall-rules(5),
    shorewall.conf(5), shorewall-tcclasses(5), shorewall-tcdevices(5),
    shorewall-tcrules(5), shorewall-tos(5), shorewall-tunnels(5),
    shorewall-zones(5)