shorewall_code/Shorewall-common/releasenotes.txt
2008-04-09 15:26:05 +00:00

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Shorewall 4.1 Patch Release 7.
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R E L E A S E 4 . 1 H I G H L I G H T S
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1) Support is included for multiple internet providers through the same
ethernet interface.
2) Support for NFLOG has been added.
3) Enhanced operational logging.
4) The tarball installers now work under Cygwin.
5) Shorewall-perl now supports IFB devices which allow traffic shaping of
incoming traffic.
6) Shorewall-perl supports definition of u32 traffic classification
filters.
Migration Issues.
1) Previously, when HIGH_ROUTE_MARKS=Yes, Shorewall allowed non-zero
mark values < 256 to be assigned in the OUTPUT chain. This has been
changed so that only high mark values may be assigned
there. Packet marking rules for traffic shaping of packets
originating on the firewall must be coded in the POSTROUTING table.
2) Previously, Shorewall did not range-check the value of the
VERBOSITY option in shorewall.conf. Beginning with Shorewall 4.1:
a) A VERBOSITY setting outside the range -1 through 2 is rejected.
b) After the -v and -q options are applied, the resulting value is
adjusted to fall within the range -1 through 2.
3) Specifying a destination zone in a NAT-only rule now generates a
warning and the destination zone is ignored. NAT-only rules are:
NONAT
REDIRECT-
DNAT-
4) The default value for LOG_MARTIANS has been changed. Previously,
the defaults were:
Shorewall-perl - 'Off'
Shorewall-shell - 'No'
The new default values are:
Shorewall-perl - 'On'
Shorewall-shell - 'Yes'.
Shorewall-perl users may:
a) Accept the new default -- martians will be logged from all
interfaces with route filtering except those with log_martians=0
in /etc/shorewall/interfaces.
b) Explicitly set LOG_MARTIANS=Off to maintain compatibility with
prior versions of Shorewall.
Shorewall-shell users may:
a) Accept the new default -- martians will be logged from all
interfaces with the route filtering enabled.
b) Explicitly set LOG_MARTIONS=No to maintain compatibility with
prior versions of Shorewall.
5) The value of IMPLICIT_CONTINUE in shorewall.conf (and samples) has
been changed from Yes to No.
6) The 'norfc1918' option is deprecated. Use explicit rules instead.
Note that there is a new 'Rfc1918' macro that acts on addresses
reserved by RFC 1918.
Problems corrected in Shorewall 4.1.7.
1) Previously, when IP_FORWARDING=Yes in shorewall.conf, Shorewall
would enable ip forwarding before instantiating the rules. This
could lead to incorrect connection tracking entries being created
between the time that forwarding was enabled and when the nat table
rules were instantiated.
Beginning with Shorewall 4.0.11, enabling of forwarding is deferred
until after the rules are in place.
Problems corrected in Shorewall-perl 4.1.7.
1) Perl run-time errors occurred if an unknown service was named in
the /etc/shorewall/tcfilters file.
2) Trailing columns containing '-' would outwit Shorewall-perl's
detection of 'too few columns' errors.
3) 'shorewall start' could fail with an error similar to the following:
RTNETLINK answers: Invalid argument
We have an error talking to the kernel
ERROR: Command "tc filter add dev bond0.207 parent 1:0 protocol ip
pref 10 u32 match ip protocol 6 0xff match u8 0x05 0x0f at 0 match u16
0x0000 0xffc0 at 2 match u8 0x10 0xff at 33 flowid 1:11" Failed
/sbin/shorewall: line 723: 755 Terminated
$SHOREWALL_SHELL ${VARDIR}/.restart $debugging restart
4) A POLICY of ":" in /etc/shorewall/policy would produce Perl
run-time errors.
5) An INTERFACE of ":" in /etc/shorewall/interfaces would produce Perl
run-time errors.
6) A MARK of ":" in /etc/shorewall/tcrules would produce Perl
run-time errors.
New Features in 4.1.7.
1) If an interface fails when using balanced multi-ISP routing, the
default route is lost. If there are remaining working interfaces
with dynamic gateway addresses, Shorewall will be unable to
determine those gateways.
Beginning with Shorewall (Shorewall-lite) 4.1.7, the 'init' script
may participate in gateway detection by setting variables with
pre-determined names as follows:
<gw>_GATEWAY
where <gw> is the interface name:
- in upper case
- with any characters not allowed in shell variable names
replaced by '_'.
Example (from OpenWRT):
Interface: eth0.1
Variable: ETH0_1_GATEWAY
/etc/shorewall/init:
ETH0_1_GATEWAY=$(uci get /var/state/network.wan0.gateway)
2) A new CONNBYTES column has been added to the tcrules file. The
column defines a byte or packet range that the connection must fall
within in order for the rule to match. The contents are:
[!]<min>:[<max>[:{O|R|B}[:{B|P|A}]]]
! matches if the the packet/byte count is not within the range
defined by <min> and <max>.
<min> is an integer which defines the beginning of the byte/packet
range.
<max> is an integer which defines the end of the byte/packet range.
If omitted, only the beginning of the range is checked.
The first letter gives the direction which the range refers to:
O - The original direction of the connection.
R - The opposite direction from the original connection.
B - The total of both directions.
If omitted, 'B' is assumed.
The second letter determins what the range refers to.
B - Bytes
P - Packets
A - Average packet size.
If omitted, 'B' is assumed.
Examples:
1000000: - Connection has transferred a total of
at least 1,000,000 bytes.
1000000::R - Connection has transferred at least
1,000,000 bytes in the direction opposite
of the original direction (typical of a
large download).
1000000::O:P - Connection has sent at least 1,000,000
packets in the direction of the original
connection.
3) A new MANGLE_ENABLED option is added to shorewall.conf. The default
setting is 'Yes' which causes Shorewall to assume responsibility for
the Netfilter mangle table.
When MANGLE_ENABLED is set to 'No', Shorewall assumes no
responsibility for that table. In this setting:
a) Shorewall doesn't alter the mangle table.
b) You may not use Shorewall Traffic Shaping (TC_ENABLED must be
set to 'No'.
c) The tcrules file is ignored.
d) The providers file must be empty.
e) All entries in tcdevices must specify the 'classify' option and
traffic classification may only occur using the tcfilters file.
This allows for another application running on your firewall to
take over the mangle table and use it for it's own purposes.
4) Shorewall-perl now supports an ORIGINAL DEST column in macro files.
The column must be left empty if the macro is to be used in the
body of an action.
The new column is placed between the SOURCE PORT(S) and RATE LIMIT
columns. So that Shorewall-perl can determine which column layout
each macro has, a new FORMAT directive is added:
FORMAT {1|2}
The default is FORMAT 1 which is the old format. FORMAT 2 specifies
that the macro is in the new format.
5) Shorewall-perl implements a new Rfc1918 macro that deals with
RFC 1918 addresses. This macro should be used in place of
the 'norfc1918' interface option which is deprecated.
The macro body is:
#ACTION SOURCE DEST PROTO DEST SOURCE ORIGINAL RATE USER/
# PORT(S) PORT(S) DEST LIMIT GROUP
FORMAT 2
PARAM SOURCE:10.0.0.0/8,172.16.0.0/12,192.168.0.0/16 \
DEST - - - - - -
PARAM SOURCE DEST - - - 10.0.0.0/8,172.16.0.0/12,192.168.0.0/16
#LAST LINE -- ADD YOUR ENTRIES BEFORE THIS ONE -- DO NOT REMOVE
The 'norfc1918' option on the interface associated with zone 'z'
and with RFC1018_STRICT=Yes is equivalent to:
Rfc1918(DROP) z all
6) A better way to perform RFC 1918 filtration is to null-route the
address ranges reserved by RFC 1918. You can do that by setting the
new NULL_ROUTE_RFC1918 option to 'Yes' in shorewall.conf.
It is highly recommended that you also set ROUTE_FILTER=Yes to get
Martian messages. These will help diagnose problems where you need
to be able to access hosts with RFC 1918 addresses that are outside
of your local networks. Sometimes, these can be subtle such as the
case where your ISP is using RFC 1918 addresses on their DHCP
servers.
NULL_ROUTE_RFC1918 defaults to 'No' and is only supported by
Shorewall-perl; Shorewall-shell ignores the option.
7) There is now a macro.SANE which supports network-attached
scanners. Shorewall now automatically loads the sane connection
tracking helper module.
Thanks for this feature go to Tuomo Soini.
New Features in Shorewall 4.1.
1) Shorewall 4.1 contains support for multiple Internet providers
through a single ethernet interface. Configuring two providers
through a single interface differs from two providers through two
interfaces in several ways.
a) Only ethernet (or ethernet-like) interfaces can be used. For
inbound traffic, the MAC addresses of the gateway routers is used
to determine which provider a packet was received through. Note
that only routed traffic can be categorized using this technique.
b) You must specify the address on the interface that corresponds to
a particular provider in the INTERFACE column by following the
interface name with a colon (":") and the address.
c) Entries in /etc/shorewall/masq must be qualified by the provider
name (or number).
d) This feature requires Realm Match support in your kernel and
iptables. If you use a capabilities file, you need to regenerate
the file with Shorewall 4.1 or Shorewall-lite 4.1.
e) You must add route_rules entries for networks that are accessed
through a particular provider.
f) If you have additional IP addresses through either provider,
you must add route_rules to direct traffic FROM each of those
addresses through the appropriate provider.
g) You must add MARK rules for any traffic that you know originates
from a particular provider.
Example:
Providers Blarg (1) and Avvanta (2) are both connected to
eth0. The firewall's IP address with Blarg is 206.124.146.176/24
(gateway 206.124.146.254) and the IP address from Avvanta is
130.252.144.8/24 (gateway 130.252.144.254). We have a second IP
address (206.124.146.177) from Blarg.
/etc/shorewall/providers:
#PROVIDER NUMBER MARK DUPLICATE INTERFACE GATEWAY
Blarg 1 1 main eth0:206.124.146.176 206.124.146.254 ...
Avvanta 2 2 main eth0:130.252.144.8 130.252.144.254 ...
/etc/shorewall/masq:
#INTERFACE SOURCE ADDRESS
eth0(Blarg) 130.252.144.8 206.124.146.176
eth0(Avvanta) 206.124.146.176 130.252.144.8
eth0(Blarg) eth1 206.124.146.176
eth0(Avvanta) eth1 130.252.144.8
/etc/shorewall/route_rules:
#SOURCE DEST PROVIDER PRIORITY
- 206.124.146.0/24 Blarg 1000
- 130.252.144.0/24 Avvanta 1000
206.124.146.177 - Blarg 26000
/etc/shorewall/tcrules
#MARK/CLASSIFY SOURCE DEST
1 eth0:206.124.146.0/24 0.0.0.0/0
2 eth0:130.242.144.0/24 0.0.0.0/0
2) You may now include the name of a table (nat, mangle or filter) in
a 'shorewall refresh' command by following the table name with a
colon (e.g., mangle:). This causes all non-builtin chains in the
table to be reloaded.
Example:
shorewall refresh nat:
3) When no chain name is given to the 'shorewall refresh' command, the
mangle table is refreshed along with the blacklist chain (if
any). This allows you to modify /etc/shorewall/tcrules and install
the changes using 'shorewall refresh'.
4) Support for the NFLOG log target has been added. NFLOG is a
successor to ULOG. In addition, both ULOG and NFLOG may be followed
by a list of up to three numbers in parentheses.
The first number specifies the netlink group (1-32). If omitted
(e.g., NFLOG(,0,10)) then a value of 1 is assumed.
The second number specifies the maximum number of bytes to copy. If
omitted, 0 (no limit) is assumed.
The third number specifies the number of log messages that should
be buffered in the kernel before they are sent to user space. The
default is 1.
Examples:
/etc/shorewall/shorewall.conf:
MACLIST_LOG_LEVEL=NFLOG(1,0,1)
/etc/shorewall/rules:
ACCEPT:NFLOG(1,0,1) vpn fw tcp ssh,time,631,8080
5) Shorewall-perl 4.1 implements an alternative syntax for macro
parameters and for the NFQUEUE queue number. Rather than following
the macro name (or NFQUEUE) with a slash ("/") and the parameter,
the parameter may be enclosed in parentheses.
Examples -- each pair shown below are equivalent:
DNS/ACCEPT DNS(ACCEPT)
NFQUEUE/3 NFQUEUE(3)
The old syntax will still be accepted but will cease to be documented
in some future Shorewall release.
6) Shorewall 4.1 contains enhanced operational logging capabilities
through a set of related enhancements to Shorewall-common and
Shorewall-perl. The enhancements are not supported by
Shorewall-shell nor are they supported by Shorewall-lite except
when the script is compiled using Shorewall-perl.
a) The STARTUP_LOG option in /etc/shorewall/shorewall.conf gives
the name of the Shorewall operational log. The log will be
created if it does not exist.
b) The LOG_VERBOSITY option in /etc/shorewall/shorewall.conf gives
the verbosity at which logging will occur. It uses the same
value range as VERBOSITY:
-1 Do not log
0 Almost quiet
1 Only major steps
2 Verbose
c) An absolute VERBOSITY may be specified on the command line
using the -v option followed by -1,0,1 or 2.
Example:
shorewall -v2 check
d) The /etc/init.d/shorewall script supplied with the
shorewall.net packages sets '-v0' as the default. This may be
overridden with the OPTIONS setting in /etc/defaults/shorewall or
/etc/sysconfig/shorewall.
Logging occurs on both Shorewall-perl and the generated script when
the following commands are issued:
start
restart
refresh
Messages in the log are always timestamped.
This change implemented two new options to the Shorewall-perl
compiler (/usr/share/shorewall-perl/compiler.pl).
--log=<logfile>
--log_verbosity={-1|0-2}
The --log option is ignored when --log_verbosity is not supplied or
is supplied with value -1.
To avoid a proliferation of parameters to
Shorewall::Compiler::compile(), that function has been changed to
use named parameters. Parameter names are:
object Object file. If omitted or '', the
configuration is syntax checked.
directory Directory. If omitted or '', configuration
files are located using
CONFIG_PATH. Otherwise, the directory named by
this parameter is searched first.
verbosity Verbosity; range -1 to 2
timestamp 0|1 -- timestamp messages.
debug 0|1 -- include stack trace in warning/error
messages.
export 0|1 -- compile for export.
chains List of chains to be reloaded by 'refresh'.
log File to log compiler messages to.
log_verbosity Log Verbosity; range -1 to 2.
Those parameters that are supplied must have defined values.
Defaults are:
object '' ('check' command)
directory ''
verbosity 1
timestamp 0
debug 0
export 0
chains ''
log ''
log_verbosity -1
Example:
use lib '/usr/share/shorewall-perl/';
use Shorewall::Compiler;
compiler( object => '/root/firewall',
log => '/root/compile.log',
log_verbosity => 2 );
7) Previously, when HIGH_ROUTE_MARKS=Yes, Shorewall allowed non-zero
mark values < 256 to be assigned in the OUTPUT chain. This has been
changed so that only high mark values may be assigned
there. Packet marking rules for traffic shaping of packets
originating on the firewall must be coded in the POSTROUTING chain.
8) Previously, Shorewall did not range-check the value of the
VERBOSITY option in shorewall.conf. Beginning with Shorewall 4.1:
a) A VERBOSITY setting outside the range -1 through 2 is rejected.
b) After the -v and -q options are applied, the resulting value is
adjusted to fall within the range -1 through 2.
9) The tcdevices file has been extended to include an OPTIONS
column. Currently only a single option is defined.
classify When specified, you must use explicit CLASSIFY tcrules
to classify traffic by class. Shorewall will not create
any CLASSIFY rules to classify traffic by mark value.
See http://www.shorewall.net/traffic_shaping.htm for further
information.
10) COMMENT lines are now supported in macro bodies by Shorewall-perl
and are ignored by the Shorewall-shell compiler.
COMMENT lines in macros work slightly differently from COMMENT
lines in other files. COMMENT lines in macros are ignored if
COMMENT support is not available or if there was a COMMENT in use
when the top-level macro was invoked. This allows the
following:
/etc/shorewall/macro.SSH:
#ACTION SOURCE PROTO DEST SOURCE RATE USER/
# PORT(S) PORT(S) LIMIT GROUP
COMMENT My SSH Macro
PARAM - - tcp 22
/etc/shorewall/rules:
COMMENT Allow SSH from home
SSH/ALLOW net:$MYIP $FW
COMMENT
The comment line in macro.SSH will not override the
COMMENT line in the rules file and the generated rule will show
/* Allow SSH from home */
when displayed through the Shorewall show and dump commands.
If a macro is invoked and there is no current comment, then the
name of the macro automatically becomes the current comment. This
makes macros self-commenting.
11) If the program named in SHOREWALL_SHELL doesn't exist or is not
executable, Shorewall and Shorewall-lite now both fall back to
/bin/sh after issuing a warning message. Previously, both
terminated with a fatal error.
12) Shorewall-perl now generates fatal error conditions if there are
no IPv4 zones defined or there are no interfaces defined.
13) Shorewall now unconditionally uses tc filter rules to classify
traffic by MARK value. Previously, Shorewall used the CLASSIFY
target in the POSTROUTING chain if it was available.
14) The Shorewall-common installer (install.sh) now works on Windows
under Cygwin.
To install Shorewall-perl under Cygwin:
$ tar -zxf shorewall-perl-4.x.y.tar.bz2
$ tar -zxf shorewall-common-4.x.y.tar.bz2
$ cd shorewall-perl-4.x.y
$ USER=<your user id> GROUP=None ./install.sh
$ cd ../shorewall-common-4.x.y
$ USER=<your user id> GROUP=None ./install.sh
The 'shorewall' program is installed in /bin/ (a.k.a, /usr/bin/).
15) When installing on Cygwin, /etc/shorewall is no longer fully
populated. Rather, only the shorewall.conf and params files are
installed. As always, the full configuration file set is installed
in /usr/share/shorewall/configfiles.
16) Specifying a destination zone in a NAT-only rule now generates a
warning and the destination zone is ignored. NAT-only rules are:
NONAT
REDIRECT-
DNAT-
17) The /etc/shorewall/masq and /etc/shorewall/nat file now accept a
comma-separated list of interface names where before only a single
interface name could be listed (Shorewall-perl only).
This feature is not for beginners. It iterates over the
list of interfaces, substituting each interface in place of the
list and processing the resulting entry according to the semantics
of earlier Shorewall versions. If you don't know where to use this,
don't try.
Example 1:
/etc/shorewall/masq:
#INTERFACE SOURCE ADDRESS
eth0,eth1 eth2 1.2.3.4
equivalent to:
#INTERFACE SOURCE ADDRESS
eth0 eth2 1.2.3.4
eth1 eth2 1.2.3.4
Example 2:
/etc/shorewall/masq:
#INTERFACE SOURCE ADDRESS
eth0,eth1::192.168.1.0/24 eth2 1.2.3.4
equivalent to:
#INTERFACE SOURCE ADDRESS
eth0::192.168.1.0/24 eth2 1.2.3.4
eth1::192.168.1.0/24 eth2 1.2.3.4
Example 3:
/etc/shorewall/nat:
#EXTERNAL INTERFACE INTERNAL
206.124.146.178 eth0,wlan0 192.168.1.3
equivalent to:
#EXTERNAL INTERFACE INTERNAL
206.124.146.178 eth0 192.168.1.3
206.124.146.178 wlan0 192.168.1.3
18) Previously, the INTERFACE name used in the masq, nat and netmap
files had to exactly match the name of an interface from the
interfaces file. Beginning with Shorewall-perl 4.1.4, the
interface may loosely match a wildcard entry in the interfaces
file.
Example:
/etc/shorewall/interfaces:
vpn tun+
/etc/shorewall/masq:
tun1 192.168.4.0/24
19) Previously, Shorewall classified non-firewall zones as either
'simple' or 'complex'. Attributes of a zone which made it 'complex'
included:
- The zone was of type 'ipsec' or 'ipsec4' or it had a hosts
entry with the 'ipsec' options.
- The zone had OPTIONS, IN OPTIONS or OUT OPTIONS
- The zone had more than one network on a given interface
- The zone had a hosts file entry with an exclusion.
- The zone had a hosts file entry specifying an ipset.
The handling of 'simple' and 'complex' zones was different.
- complex zones had their own 'forward' chain (named
'<zone>_frwd').
- complex zones with exclusions had their own 'input' and
'output' chains.
Beginning with Shorewall-perl 4.1, all non-firewall zones will be
treated as 'complex'. This will have the effect of one additional
filter chain per zone but in most cases, the average number of
filter rules traversed by a connection request will be reduced.
20) The need for interface-specific chains (such as eth0_in, eth4_fwd,
etc.) in the filter table has been drastically reduced. This has
the effect of reducing the average number of rules that each packet
must traverse.
21) The default value for LOG_MARTIANS is now 'Yes' ('On' in
Shorewall-perl). Previously, the default value was 'No' ('Off' in
Shorewall-perl). The shorewall.conf file has also been
updated to specify a value of 'Yes' (which is interpreted as 'On'
by Shorewall-perl).
22) Shorewall-perl now generates an error when a MAC address appears in
a traffic shaping rule in the OUTPUT or POSTROUTING chains.
23) Macros are now self-commenting under control of a new AUTO_COMMENT
option in shorewall.conf. When this option is set, if there is not
a current comment when a macro is invoked, the behavior under
Shorewall-perl is as if the first line of the macro file was
"COMMENT <macro name>".
So, if you have this rule:
SSH/ACCEPT loc fw
then the generated netfilter rule will include "/* SSH */" when
viewed with 'iptables -L' or 'shorewall show loc2fw' or 'shorewall
dump'.
The AUTO_COMMENT option has a default value of 'Yes' and is only
available under Shorewall-perl. The option is ignored by
Shorewall-shell.
24) The default value for the IMPLICIT_CONTINUE option has been changed
to 'No'.
25) Shorewall-perl now supports an 'l2tp' tunnel type. It opens UDP
port 1701 in both directions and assumes that the source port will
also be 1701. Some implementations (particularly OS X) use a
different source port. In that case, you should use
'generic:udp:1701' rather than 'l2tp'.
26) The /etc/shorewall/tcdevices and /etc/shorewall/tcclasses files
have undergone some changes, especially when the 'classify' option
has been specified.
Normally Shorewall assigns interface numbers sequentially to
devices listed in /etc/shorewall/tcdevices. Beginning with
Shorewall 4.1.6, you can explicitly specify inteface numbers by
prefixing the interface name with the interface number and a colon:
Example:
#INTERFACE IN-BANDWITH OUT-BANDWIDTH OPTIONS
1:eth0 1300kbit 384kbit classify
2:eth1 5600kbit 1000kbit
In /etc/shorewall/tcclasses:
a) You can specify the INTERFACE using either the interface name
or interface number.
b) classes associated with devices which have the 'classify'
option _must_ specify a class number by following the interface
name/number with a colon (":") and the class number. The same
class number may be used for classes defined on different
interfaces but a class number may not be the same as any
interface number.
A class number may be specified when 'classify' has not been
specified for the associated device. When a class number has not
been given, the default class number remains the mark value
prefixed by "1".
27) Shorewall now supports Intermediate Functional Block (IFB) devices.
These devices allow shaping of incoming traffic.
The 'ifb' module is available in the kernels included with today's
distributions. You must load the module manually:
If your distribution has modprobe:
modprobe ifb [ numifbs=<number> ]
Otherwise:
insmod <path to net driver modules>/ifb.ko [ numifbs=<number> ]
By default, the module automatically creates two IFB devices (ifb0
and ifb1). To create only one, specify 'numifbs=1'.
Example:
ursa:~ # modprobe ifb numifbs=1
ursa:~ # ip link ls
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether cc:2b:cb:24:1b:00 brd ff:ff:ff:ff:ff:ff
3: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:1a:73:db:8c:35 brd ff:ff:ff:ff:ff:ff
4: ifb0: <BROADCAST,NOARP> mtu 1500 qdisc noop qlen 32
link/ether 26:99:d8:7d:32:26 brd ff:ff:ff:ff:ff:ff
ursa:~ #
After you have created the IFB(s), you must bring it(them) up:
ip link set dev ifb0 up
You can place all of this in /etc/shorewall/init as follows:
modprobe ifb numifbs=1
ip link set dev ifb0 up
The /etc/shorewall/tcdevices file has been extended to include an
additional REDIRECTED DEVICES column. To convert your configuration
to use an IFB:
a) Look at your current /etc/shorewall/tcdevices file. Suppose you
have:
#INTERFACE IN-BANDWIDTH OUT-BANDWIDTH OPTIONS
eth0 1300kbit 384kbit -
Change it as follows:
#INTERFACE IN-BANDWIDTH OUT-BANDWIDTH OPTIONS REDIRECTED
# DEVICES
eth0 - 384kkbit -
ifb0 - 1300kbit - eth0
Note that the old IN-BANDWIDTH for eth0 has become the
OUT-BANDWIDTH for ifb0 and that neither device has an
IN-BANDWIDTH in the new configuration.
Finally note that eth0 has been specified as a REDIRECTED device
for the IFB.
b) There are no Netfilter hooks between the real device (eth0) and
the IFB (ifb0). So tcrules cannot be used to specify shaping of
traffic leaving the IFB. To allow that traffic to be classified,
a new /etc/shorewall/tcfilters file has been added.
/etc/shorewall/tcfilters can be used for classifying traffic on
any interface. When using entries in that file, it is important
to realize that those entries act on packets as they appear 'on
the wire'. That means that on output, SNAT/MASQUERADE has been
applied and on input (output to an IFB), DNAT has not yet been
applied.
Columns in the file are:
INTERFACE:CLASS
The interface name or number followed by a colon (":")
and the class number.
SOURCE
Source IP address. May be a host or network address.
Specify "-" if any SOURCE address should match.
DEST
Destination IP address. May be a host or network
address. Specify "-" if any DEST address should match.
PROTO
Protocol Name/Number. Specify "-" if any PROTO should
match.
DEST PORT(S)
A comma-separated list of destination ports. May only
be given if the PROTO is tcp, udp, icmp or
sctp. Port ranges may be used, except when the PROTO is
icmp. Specify "-" if any PORT should match.
SOURCE PORT(S)
A comma-separated list of source port. May only be
given if the PROTO is tcp, udp or sctp. Port ranges
may be used unless the protocol is icmp. Specify "-" if
any PORT should match.
Entries in /etc/shorewall/tcfilters generate U32 tc filters which
may be displayed using the "shorewall show filters" ("shorewall-lite
show filters") command. Note: The 'show filters' command is an
alias for the existing 'show classifiers' command.
Note that /etc/shorewall/tcfilters provides a usable alternative to
HIGH_ROUTE_MARKS=Yes. You can use marks to select between providers
and use entries in /etc/shorewall/tcfilters (or CLASSIFY tcrules)
for traffic shaping.