Shorewall installazione e configurazione



 

Shorewall (Shoreline Firewall) è un firewall che si appoggia al sistema  Netfilter (iptables/ipchains) del kernel Linux, per una più semplice gestione di avanzate configurazioni di rete. Prima di iniziare nell'installazione di shorewall, bisogna prima disinstallare eventualmente l'altro firewall. Esempio: firestarter:

# apt-get remove --purge firestarter

# apt-get install shorewall shorewall-common shorewall-shell shorewall-doc dash

 

1) Partiamo con la configurazione del file interfaces:

# gedit /etc/shorewall/interfaces

all'interno copiamo questo:

# Shorewall version 3.0 – Sample Interfaces File for one-interface configuration.
#
# /etc/shorewall/interfaces
#
# You must add an entry in this file for each network interface on your
# firewall system.
#
# Columns are:
#
# ZONE Zone for this interface. Must match the name of a
# zone defined in /etc/shorewall/zones. You may not
# list the firewall zone in this column.
#
# If the interface serves multiple zones that will be
# defined in the /etc/shorewall/hosts file, you should
# place "-" in this column.
#
# If there are multiple interfaces to the same zone,
# you must list them in separate entries:
#
# Example:
#
# loc eth1 –
# loc eth2 –
#
# INTERFACE Name of interface. Each interface may be listed only
# once in this file. You may NOT specify the name of
# an alias (e.g., eth0:0) here; see
# https://www.shorewall.net/FAQ.htm#faq18
#
# You may specify wildcards here. For example, if you
# want to make an entry that applies to all PPP
# interfaces, use 'ppp+'.
#
# There is no need to define the loopback interface (lo)
# in this file.
#
# BROADCAST The broadcast address for the subnetwork to which the
# interface belongs. For P-T-P interfaces, this
# column is left blank.If the interface has multiple
# addresses on multiple subnets then list the broadcast
# addresses as a comma-separated list.
#
# If you use the special value "detect", the firewall
# will detect the broadcast address for you. If you
# select this option, the interface must be up before
# the firewall is started, you must have iproute
# installed.
#
# If you don't want to give a value for this column but
# you want to enter a value in the OPTIONS column, enter
# "-" in this column.
#
# OPTIONS A comma-separated list of options including the
# following:
#
# dhcp – Specify this option when any of
# the following are true:
# 1. the interface gets its IP address
# via DHCP
# 2. the interface is used by
# a DHCP server running on the firewall
# 3. you have a static IP but are on a LAN
# segment with lots of Laptop DHCP
# clients.
# 4. the interface is a bridge with
# a DHCP server on one port and DHCP
# clients on another port.
#
# norfc1918 – This interface should not receive
# any packets whose source is in one
# of the ranges reserved by RFC 1918
# (i.e., private or "non-routable"
# addresses. If packet mangling or
# connection-tracking match is enabled in
# your kernel, packets whose destination
# addresses are reserved by RFC 1918 are
# also rejected.
#
# routefilter – turn on kernel route filtering for this
# interface (anti-spoofing measure). This
# option can also be enabled globally in
# the /etc/shorewall/shorewall.conf file.
#
# logmartians – turn on kernel martian logging (logging
# of packets with impossible source
# addresses. It is suggested that if you
# set routefilter on an interface that
# you also set logmartians. This option
# may also be enabled globally in the
# /etc/shorewall/shorewall.conf file.
#
# blacklist – Check packets arriving on this interface
# against the /etc/shorewall/blacklist
# file.
#
# maclist – Connection requests from this interface
# are compared against the contents of
# /etc/shorewall/maclist. If this option
# is specified, the interface must be
# an ethernet NIC and must be up before
# Shorewall is started.
#
# tcpflags – Packets arriving on this interface are
# checked for certain illegal combinations
# of TCP flags. Packets found to have
# such a combination of flags are handled
# according to the setting of
# TCP_FLAGS_DISPOSITION after having been
# logged according to the setting of
# TCP_FLAGS_LOG_LEVEL.
#
# proxyarp –
# Sets
# /proc/sys/net/ipv4/conf/<interface>/proxy_arp.
# Do NOT use this option if you are
# employing Proxy ARP through entries in
# /etc/shorewall/proxyarp. This option is
# intended soley for use with Proxy ARP
# sub-networking as described at:
#
#
# routeback – If specified, indicates that Shorewall
# should include rules that allow
# filtering traffic arriving on this
# interface back out that same interface.
#
# arp_filter – If specified, this interface will only
# respond to ARP who-has requests for IP
# addresses configured on the interface.
# If not specified, the interface can
# respond to ARP who-has requests for
# IP addresses on any of the firewall's
# interface. The interface must be up
# when Shorewall is started.
#
# arp_ignore[=<number>]
# – If specified, this interface will
# respond to arp requests based on the
# value of <number>.
#
# 1 – reply only if the target IP address
# is local address configured on the
# incoming interface
#
# 2 – reply only if the target IP address
# is local address configured on the
# incoming interface and both with the
# sender's IP address are part from same
# subnet on this interface
#
# 3 – do not reply for local addresses
# configured with scope host, only
# resolutions for global and link
# addresses are replied
#
# 4-7 – reserved
#
# 8 – do not reply for all local
# addresses
#
# If no <number> is given then the value
# 1 is assumed
#
# WARNING — DO NOT SPECIFY arp_ignore
# FOR ANY INTERFACE INVOLVED IN PROXY ARP.
#
# nosmurfs – Filter packets for smurfs
# (packets with a broadcast
# address as the source).
#
# Smurfs will be optionally logged based
# on the setting of SMURF_LOG_LEVEL in
# shorewall.conf. After logging, the
# packets are dropped.
#
# detectnets – Automatically taylors the zone named
# in the ZONE column to include only those
# hosts routed through the interface.
#
# upnp – Incoming requests from this interface
# may be remapped via UPNP (upnpd).
#
# WARNING: DO NOT SET THE detectnets OPTION ON YOUR
# INTERNET INTERFACE.
#
# The order in which you list the options is not
# significant but the list should have no embedded white
# space.
#
# Example 1: Suppose you have eth0 connected to a DSL modem and
# eth1 connected to your local network and that your
# local subnet is 192.168.1.0/24. The interface gets
# it's IP address via DHCP from subnet
# 206.191.149.192/27. You have a DMZ with subnet
# 192.168.2.0/24 using eth2.
#
# Your entries for this setup would look like:
#
# net eth0 206.191.149.223 dhcp
# local eth1 192.168.1.255
# dmz eth2 192.168.2.255
#
# Example 2: The same configuration without specifying broadcast
# addresses is:
#
# net eth0 detect dhcp
# loc eth1 detect
# dmz eth2 detect
#
# Example 3: You have a simple dial-in system with no ethernet
# connections.
#
# net ppp0 –
#
# For additional information, see
#
#
###############################################################################
#ZONE INTERFACE BROADCAST OPTIONS
net eth0   detect      routefilter,dhcp,tcpflags,logmartians,nosmurfs
#LAST LINE — ADD YOUR ENTRIES BEFORE THIS ONE — DO NOT REMOVE

 

Attenzione:Se al posto del router abbiamo un modem cambiare eth0 con ppp0. In ogni caso cercare di adattarlo alle nostre esigenze e configurazione.

 

2) Configurazione del file policy:

# gedit /etc/shorewall/policy

all'interno copiamo questo:

# Shorewall version 3.0 – Sample Policy File for one-interface configuration.
#
# /etc/shorewall/policy
#
# 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).
#
# INTRA-ZONE POLICIES ARE PRE-DEFINED
#
# For $FW and for all of the zoned 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).
#
# Columns are:
#
# SOURCE Source zone. Must be the name of a zone defined
# in /etc/shorewall/zones, $FW or "all".
#
# DEST Destination zone. Must be the name of a zone defined
# in /etc/shorewall/zones, $FW or "all"
#
# POLICY Policy if no match from the rules file is found. Must
# be "ACCEPT", "DROP", "REJECT", "CONTINUE" or "NONE".
#
# ACCEPT – Accept the connection
# DROP – Ignore the connection request
# REJECT – For TCP, send RST. For all other,
# send "port unreachable" ICMP.
# QUEUE – Send the request to a user-space
# application using the QUEUE target.
# CONTINUE – Pass the connection request past
# any other rules that it might also
# match (where the source or
# destination zone in those rules is
# a superset of the SOURCE or DEST
# in this policy).
# NONE – Assume that there will never be any
# packets from this SOURCE
# to this DEST. Shorewall will not set
# up any infrastructure to handle such
# packets and you may not have any
# rules with this SOURCE and DEST in
# the /etc/shorewall/rules file. If
# such a packet _is_ received, the
# result is undefined. NONE may not be
# used if the SOURCE or DEST columns
# contain the firewall zone ($FW) or
# "all".
#
# If this column contains ACCEPT, DROP or REJECT and a
# corresponding common action is defined in
# /etc/shorewall/actions (or
# /usr/share/shorewall/actions.std) then that action
# will be invoked before the policy named in this column
# is enforced.
#
# LOG LEVEL 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.
#
# Beginning with Shorewall version 1.3.12, you may
# also specify ULOG (must be in upper case). This will
# log to the ULOG target and sent to a separate log
# through use of ulogd
# ).
#
# If you don't want to log but need to specify the
# following column, place "-" here.
#
# LIMIT:BURST If passed, specifies the maximum TCP connection rate
# and the size of an acceptable burst. If not specified,
# TCP connections are not limited.
#
# See for additional information.
#
###############################################################################
#SOURCE DEST POLICY LOG LEVEL LIMIT:BURST
$FW net ACCEPT
net all DROP info
# The FOLLOWING POLICY MUST BE LAST
all all REJECT info
#LAST LINE — ADD YOUR ENTRIES ABOVE THIS LINE — DO NOT REMOVE

 

 

3) Creazione del file di configurazione zones:

# gedit /etc/shorewall/zones

all'interno copiamo questo:

# Shorewall version 3.0 – Sample Zones File for one-interface configuration.
#
# /etc/shorewall/zones
#
# This file determines your network zones.
#
# Columns are:
#
# ZONE Short name of the zone (5 Characters or less in length).
# The names "all" and "none" are reserved and may not be
# used as zone names.
#
# Where a zone is nested in one or more other zones,
# you may follow the (sub)zone name by ":" and a
# comma-separated list of the parent zones. The parent
# zones must have been defined in earlier records in this
# file.
#
# Example:
#
# #ZONE TYPE OPTIONS
# a ipv4
# b ipv4
# c:a,b ipv4
#
# Currently, Shorewall uses this information only to reorder the
# zone list so that parent zones appear after their subzones in
# the list. In the future, Shorewall may make more extensive use
# of that information.
#
# TYPE ipv4 – This is the standard Shorewall zone type and is the
# default if you leave this column empty or if you enter
# "-" in the column. Communication with some zone hosts
# may be encrypted. Encrypted hosts are designated using
# the 'ipsec'option in /etc/shorewall/hosts.
# ipsec – Communication with all zone hosts is encrypted
# Your kernel and iptables must include policy
# match support.
# firewall
# – Designates the firewall itself. You must have
# exactly one 'firewall' zone. No options are
# permitted with a 'firewall' zone. The name that you
# enter in the ZONE column will be stored in the shell
# variable $FW which you may use in other configuration
# files to designate the firewall zone.
#
# OPTIONS, A comma-separated list of options as follows:
# IN OPTIONS,
# OUT OPTIONS reqid=<number> where <number> is specified
# using setkey(8) using the 'unique:<number>
# option for the SPD level.
#
# spi=<number> where <number> is the SPI of
# the SA used to encrypt/decrypt packets.
#
# proto=ah|esp|ipcomp
#
# mss=<number> (sets the MSS field in TCP packets)
#
# mode=transport|tunnel
#
# tunnel-src=<address>[/<mask>] (only
# available with mode=tunnel)
#
# tunnel-dst=<address>[/<mask>] (only
# available with mode=tunnel)
#
# strict Means that packets must match all rules.
#
# next Separates rules; can only be used with
# strict..
#
# Example:
# mode=transport,reqid=44
#
# The options in the OPTIONS column are applied to both incoming
# and outgoing traffic. The IN OPTIONS are applied to incoming
# traffic (in addition to OPTIONS) and the OUT OPTIONS are
# applied to outgoing traffic.
#
# If you wish to leave a column empty but need to make an entry
# in a following column, use "-".
#
# THE ORDER OF THE ENTRIES IN THIS FILE IS IMPORTANT IF YOU HAVE NESTED OR
# OVERLAPPING ZONES DEFINED THROUGH /etc/shorewall/hosts.
#
# See
###############################################################################
#ZONE TYPE OPTIONS IN OUT
# OPTIONS OPTIONS
fw firewall
net ipv4
#LAST LINE – ADD YOUR ENTRIES ABOVE THIS ONE – DO NOT REMOVE

 

 

4) Configurazione del file rules.

# gedit /etc/shorewall/rules

all'interno copiamo questo:

 

# Shorewall version 3.0 – Sample Rules File for one-interface configuration.
#
# /etc/shorewall/rules
#
# Rules in this file govern connection establishment. Requests and
# responses are automatically allowed using connection tracking. For any
# particular (source,dest) pair of zones, the rules are evaluated in the
# order in which they appear in this file and the first match is the one
# that determines the disposition of the request.
#
# In most places where an IP address or subnet is allowed, you
# can preceed the address/subnet with "!" (e.g., !192.168.1.0/24) to
# indicate that the rule matches all addresses except the address/subnet
# given. Notice that no white space is permitted between "!" and the
# address/subnet.
#——————————————————————————
# WARNING: If you masquerade or use SNAT from a local system to the internet,
# you cannot use an ACCEPT rule to allow traffic from the internet to
# that system. You *must* use a DNAT rule instead.
#——————————————————————————
#
# The rules file is divided into sections. Each section is introduced by
# a "Section Header" which is a line beginning with SECTION followed by the
# section name.
#
# Sections are as follows and must appear in the order listed:
#
# ESTABLISHED Packets in the ESTABLISHED state are processed
# by rules in this section.
#
# The only ACTIONs allowed in this section are
# ACCEPT, DROP, REJECT, LOG and QUEUE
#
# There is an implicit ACCEPT rule inserted
# at the end of this section.
#
# RELATED Packets in the RELATED state are processed by
# rules in this section.
#
# The only ACTIONs allowed in this section are
# ACCEPT, DROP, REJECT, LOG and QUEUE
#
# There is an implicit ACCEPT rule inserted
# at the end of this section.
#
# NEW Packets in the NEW and INVALID states are
# processed by rules in this section.
#
# WARNING: If you specify FASTACCEPT=Yes in shorewall.conf then the
# ESTABLISHED and RELATED sections must be empty.
#
# Note: If you are not familiar with Netfilter to the point where you are
# comfortable with the differences between the various connection
# tracking states, then I suggest that you omit the ESTABLISHED and
# RELATED sections and place all of your rules in the NEW section.
#
# You may omit any section that you don't need. If no Section Headers appear
# in the file then all rules are assumed to be in the NEW section.
#
# Columns are:
#
# ACTION ACCEPT, DROP, REJECT, DNAT, DNAT-, REDIRECT, CONTINUE,
# LOG, QUEUE or an <action>.
#
# ACCEPT — allow the connection request
# ACCEPT+ — like ACCEPT but also excludes the
# connection from any subsequent
# DNAT[-] or REDIRECT[-] rules
# NONAT — Excludes the connection from any
# subsequent DNAT[-] or REDIRECT[-]
# rules but doesn't generate a rule
# to accept the traffic.
# DROP — ignore the request
# REJECT — disallow the request and return an
# icmp-unreachable or an RST packet.
# DNAT — Forward the request to another
# system (and optionally another
# port).
# DNAT- — Advanced users only.
# Like DNAT but only generates the
# DNAT iptables rule and not
# the companion ACCEPT rule.
# SAME — Similar to DNAT except that the
# port may not be remapped and when
# multiple server addresses are
# listed, all requests from a given
# remote system go to the same
# server.
# SAME- — Advanced users only.
# Like SAME but only generates the
# NAT iptables rule and not
# the companion ACCEPT rule.
# REDIRECT — Redirect the request to a local
# port on the firewall.
# REDIRECT-
# — Advanced users only.
# Like REDIRET but only generates the
# REDIRECT iptables rule and not
# the companion ACCEPT rule.
#
# CONTINUE — (For experts only). Do not process
# any of the following rules for this
# (source zone,destination zone). If
# The source and/or destination IP
# address falls into a zone defined
# later in /etc/shorewall/zones, this
# connection request will be passed
# to the rules defined for that
# (those) zone(s).
# LOG — Simply log the packet and continue.
# QUEUE — Queue the packet to a user-space
# application such as ftwall
# (https://p2pwall.sf.net).
# <action> — The name of an action defined in
# /etc/shorewall/actions or in
# /usr/share/shorewall/actions.std.
# <macro> — The name of a macro defined in a
# file named macro.<macro-name>. If
# the macro accepts an action
# parameter (Look at the macro
# source to see if it has PARAM in
# the TARGET column) then the macro
# name is followed by "/" and the
# action (ACCEPT, DROP, REJECT, …)
# to be substituted for the
# parameter. Example: FTP/ACCEPT.
#
# The ACTION may optionally be followed
# by ":" and a syslog log level (e.g, REJECT:info or
# DNAT:debug). This causes the packet to be
# logged at the specified level.
#
# If the ACTION names an action defined in
# /etc/shorewall/actions or in
# /usr/share/shorewall/actions.std then:
#
# – If the log level is followed by "!' then all rules
# in the action are logged at the log level.
#
# – If the log level is not followed by "!" then only
# those rules in the action that do not specify
# logging are logged at the specified level.
#
# – The special log level 'none!' suppresses logging
# by the action.
#
# You may also specify ULOG (must be in upper case) as a
# log level.This will log to the ULOG target for routing
# to a separate log through use of ulogd
# ).
#
# Actions specifying logging may be followed by a
# log tag (a string of alphanumeric characters)
# are appended to the string generated by the
# LOGPREFIX (in /etc/shorewall/shorewall.conf).
#
# Example: ACCEPT:info:ftp would include 'ftp '
# at the end of the log prefix generated by the
# LOGPREFIX setting.
#
# SOURCE Source hosts to which the rule applies. May be a zone
# defined in /etc/shorewall/zones, $FW to indicate the
# firewall itself, "all", "all+" or "none" If the ACTION
# is DNAT or REDIRECT, sub-zones of the specified zone
# may be excluded from the rule by following the zone
# name with "!' and a comma-separated list of sub-zone
# names.
#
# When "none" is used either in the SOURCE or DEST
# column, the rule is ignored.
#
# When "all" is used either in the SOURCE or DEST column
# intra-zone traffic is not affected. When "all+" is
# used, intra-zone traffic is affected.
#
# Except when "all[+]" is specified, clients may be
# further restricted to a list of subnets and/or hosts by
# appending ":" and a comma-separated list of subnets
# and/or hosts. Hosts may be specified by IP or MAC
# address; mac addresses must begin with "~" and must use
# "-" as a separator.
#
# Hosts may be specified as an IP address range using the
# syntax <low address>-<high address>. This requires that
# your kernel and iptables contain iprange match support.
# If you kernel and iptables have ipset match support
# then you may give the name of an ipset prefaced by "+".
# The ipset name may be optionally followed by a number
# from 1 to 6 enclosed in square brackets ([]) to
# indicate the number of levels of source bindings to be
# matched.
#
# dmz:192.168.2.2 Host 192.168.2.2 in the DMZ
#
# net:155.186.235.0/24 Subnet 155.186.235.0/24 on the
# Internet
#
# loc:192.168.1.1,192.168.1.2
# Hosts 192.168.1.1 and
# 192.168.1.2 in the local zone.
# loc:~00-A0-C9-15-39-78 Host in the local zone with
# MAC address 00:A0:C9:15:39:78.
#
# net:192.0.2.11-192.0.2.17
# Hosts 192.0.2.11-192.0.2.17 in
# the net zone.
#
# Alternatively, clients may be specified by interface
# by appending ":" to the zone name followed by the
# interface name. For example, loc:eth1 specifies a
# client that communicates with the firewall system
# through eth1. This may be optionally followed by
# another colon (":") and an IP/MAC/subnet address
# as described above (e.g., loc:eth1:192.168.1.5).
#
# DEST Location of Server. May be a zone defined in
# /etc/shorewall/zones, $FW to indicate the firewall
# itself, "all". "all+" or "none".
#
# When "none" is used either in the SOURCE or DEST
# column, the rule is ignored.
#
# When "all" is used either in the SOURCE or DEST column
# intra-zone traffic is not affected. When "all+" is
# used, intra-zone traffic is affected.
#
# Except when "all[+]" is specified, the server may be
# further restricted to a particular subnet, host or
# interface by appending ":" and the subnet, host or
# interface. See above.
#
# Restrictions:
#
# 1. MAC addresses are not allowed.
# 2. In DNAT rules, only IP addresses are
# allowed; no FQDNs or subnet addresses
# are permitted.
# 3. You may not specify both an interface and
# an address.
#
# Like in the SOURCE column, you may specify a range of
# up to 256 IP addresses using the syntax
# <first ip>-<last ip>. When the ACTION is DNAT or DNAT-,
# the connections will be assigned to addresses in the
# range in a round-robin fashion.
#
# If you kernel and iptables have ipset match support
# then you may give the name of an ipset prefaced by "+".
# The ipset name may be optionally followed by a number
# from 1 to 6 enclosed in square brackets ([]) to
# indicate the number of levels of destination bindings
# to be matched. Only one of the SOURCE and DEST columns
# may specify an ipset name.
#
# The port that the server is listening on may be
# included and separated from the server's IP address by
# ":". If omitted, the firewall will not modifiy the
# destination port. A destination port may only be
# included if the ACTION is DNAT or REDIRECT.
#
# Example: loc:192.168.1.3:3128 specifies a local
# server at IP address 192.168.1.3 and listening on port
# 3128. The port number MUST be specified as an integer
# and not as a name from /etc/services.
#
# if the ACTION is REDIRECT, this column needs only to
# contain the port number on the firewall that the
# request should be redirected to.
#
# PROTO Protocol – Must be "tcp", "udp", "icmp", "ipp2p",
# "ipp2p:udp", "ipp2p:all" a number, or "all".
# "ipp2p*" requires ipp2p match support in your kernel
# and iptables.
#
# DEST PORT(S) Destination Ports. A comma-separated list of Port
# names (from /etc/services), port numbers or port
# ranges; if the protocol is "icmp", this column is
# interpreted as the destination icmp-type(s).
#
# If the protocol is ipp2p, this column is interpreted
# as an ipp2p option without the leading "–" (example
# "bit" for bit-torrent). If no port is given, "ipp2p" is
# assumed.
#
# A port range is expressed as <low port>:<high port>.
#
# This column is ignored if PROTOCOL = all but must be
# entered if any of the following ields are supplied.
# In that case, it is suggested that this field contain
# "-"
#
# If your kernel contains multi-port match support, then
# only a single Netfilter rule will be generated if in
# this list and the CLIENT PORT(S) list below:
# 1. There are 15 or less ports listed.
# 2. No port ranges are included.
# Otherwise, a separate rule will be generated for each
# port.
#
# CLIENT PORT(S) (Optional) Port(s) used by the client. If omitted,
# any source port is acceptable. Specified as a comma-
# separated list of port names, port numbers or port
# ranges.
#
# If you don't want to restrict client ports but need to
# specify an ORIGINAL DEST in the next column, then
# place "-" in this column.
#
# If your kernel contains multi-port match support, then
# only a single Netfilter rule will be generated if in
# this list and the DEST PORT(S) list above:
# 1. There are 15 or less ports listed.
# 2. No port ranges are included.
# Otherwise, a separate rule will be generated for each
# port.
#
# ORIGINAL DEST (0ptional) — If ACTION is DNAT[-] or REDIRECT[-]
# then if included and different from the IP
# address given in the SERVER column, this is an address
# on some interface on the firewall and connections to
# that address will be forwarded to the IP and port
# specified in the DEST column.
#
# A comma-separated list of addresses may also be used.
# This is usually most useful with the REDIRECT target
# where you want to redirect traffic destined for
# particular set of hosts.
#
# Finally, if the list of addresses begins with "!" then
# the rule will be followed only if the original
# destination address in the connection request does not
# match any of the addresses listed.
#
# For other actions, this column may be included and may
# contain one or more addresses (host or network)
# separated by commas. Address ranges are not allowed.
# When this column is supplied, rules are generated
# that require that the original destination address
# matches one of the listed addresses. This feature is
# most useful when you want to generate a filter rule
# that corresponds to a DNAT- or REDIRECT- rule. In this
# usage, the list of addresses should not begin with "!".
#
# See https://shorewall.net/PortKnocking.html for an
# example of using an entry in this column with a
# user-defined action rule.
#
# RATE LIMIT You may rate-limit the rule by placing a value in
# this colume:
#
# <rate>/<interval>[:<burst>]
#
# where <rate> is the number of connections per
# <interval> ("sec" or "min") and <burst> is the
# largest burst permitted. If no <burst> is given,
# a value of 5 is assumed. There may be no
# no whitespace embedded in the specification.
#
# Example: 10/sec:20
#
# USER/GROUP This column may only be non-empty if the SOURCE is
# the firewall itself.
#
# The column may contain:
#
# [!][<user name or number>][:<group name or number>][+<program name>]
#
# When this column is non-empty, the rule applies only
# if the program generating the output is running under
# the effective <user> and/or <group> specified (or is
# NOT running under that id if "!" is given).
#
# Examples:
#
# joe #program must be run by joe
# :kids #program must be run by a member of
# #the 'kids' group
# !:kids #program must not be run by a member
# #of the 'kids' group
# +upnpd #program named upnpd (This feature was
# #removed from Netfilter in kernel
# #version 2.6.14).
#
# Example: Accept SMTP requests from the DMZ to the internet
#
# #ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# # PORT PORT(S) DEST
# ACCEPT dmz net tcp smtp
#
# Example: Forward all ssh and https connection requests from the
# internet to local system 192.168.1.3
#
# #ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# # PORT PORT(S) DEST
# DNAT net loc:192.168.1.3 tcp ssh,https
#
# Example: Forward all https connection requests from the internet
# to local system 192.168.1.3 with a limit of 3 per second and
# a maximum burst of 10
#
# #ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL RATE
# # PORT PORT(S) DEST LIMIT
# DNAT net loc:192.168.1.3 tcp https – – 3/sec:10
#
# Example: Redirect all locally-originating www connection requests to
# port 3128 on the firewall (Squid running on the firewall
# system) except when the destination address is 192.168.2.2
#
# #ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# # PORT PORT(S) DEST
# REDIRECT loc 3128 tcp www – !192.168.2.2
#
# Example: All https requests from the internet to address
# 130.252.100.69 are to be forwarded to 192.168.1.3
#
# #ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# # PORT PORT(S) DEST
# DNAT net loc:192.168.1.3 tcp 80 – 130.252.100.69
#
# Example: You want to accept SSH connections to your firewall only
# from internet IP addresses 130.252.100.69 and 130.252.100.70
#
# #ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL
# # PORT PORT(S) DEST
# ACCEPT net:130.252.100.69,130.252.100.70 $FW \
# tcp 22
################################################################
#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL RATE USER/
# PORT PORT(S) DEST LIMIT GROUP

# Reject Ping from the "bad" net zone.. and prevent your log from being flooded..

Ping/REJECT net $FW

# Permit all ICMP traffic FROM the firewall TO the net zone

ACCEPT $FW net icmp

#LAST LINE — ADD YOUR ENTRIES BEFORE THIS ONE — DO NOT REMOVE

 

In questo file vengono settate le regole di accesso, quindi è qui che a secondo delle esigenze di ognuno di noi vanno aperte le porte per i programmi che noi utilizziamo.  Facendo degli esempi con Amule, Deluge, Ftp, prima dell'ultima riga:

#LAST LINE — ADD YOUR ENTRIES BEFORE THIS ONE — DO NOT REMOVE

vanno inserite le regole:

# aMule
ACCEPT        net        $FW        tcp         4662
ACCEPT        $FW        net        tcp         4662
ACCEPT        net        $FW        udp        4672
ACCEPT        $FW        net        udp        4672
ACCEPT        net        $FW        udp        4665
ACCEPT        $FW        net        udp        4665

# Ftp modo passivo
ACCEPT          net             $FW             tcp             21
ACCEPT          $FW             net             tcp             21
ACCEPT          net             $FW             tcp             50000:50100
ACCEPT          $FW             net             tcp             50000:50100

#deluge
ACCEPT        net        $FW         tcp        6881:6889
ACCEPT        $FW        net         tcp        6881:6889

 

5) Per attivare shorewall all'avvio:

# gedit /etc/default/shorewall

e rimpiazzare "startup=0" con "startup=1"

6) Lanciare shorewall:

# shorewall start

7) Dopo aver fatto qualche modifica:

# shorewall restart

Per moltissime altre info, soprattutto più esaurienti e complete direttamente qua.