net/netfilter/Kconfig v3.0-rc7


Menu: Core Netfilter Configuration

NETFILTER_NETLINK_QUEUE

Netfilter NFQUEUE over NFNETLINK interface

If this option is enabled, the kernel will include support
for queueing packets via NFNETLINK.

NETFILTER_NETLINK_LOG

Netfilter LOG over NFNETLINK interface

If this option is enabled, the kernel will include support
for logging packets via NFNETLINK.

This obsoletes the existing ipt_ULOG and ebg_ulog mechanisms,
and is also scheduled to replace the old syslog-based ipt_LOG
and ip6t_LOG modules.

NF_CONNTRACK

Netfilter connection tracking support

Connection tracking keeps a record of what packets have passed
through your machine, in order to figure out how they are related
into connections.

This is required to do Masquerading or other kinds of Network
Address Translation.  It can also be used to enhance packet
filtering (see `Connection state match support' below).

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_MARK

'Connection mark tracking support'

This option enables support for connection marks, used by the
`CONNMARK' target and `connmark' match. Similar to the mark value
of packets, but this mark value is kept in the conntrack session
instead of the individual packets.

NF_CONNTRACK_SECMARK

'Connection tracking security mark support'

This option enables security markings to be applied to
connections.  Typically they are copied to connections from
packets using the CONNSECMARK target and copied back from
connections to packets with the same target, with the packets
being originally labeled via SECMARK.

If unsure, say 'N'.

NF_CONNTRACK_ZONES

'Connection tracking zones'

This option enables support for connection tracking zones.
Normally, each connection needs to have a unique system wide
identity. Connection tracking zones allow to have multiple
connections using the same identity, as long as they are
contained in different zones.

If unsure, say `N'.

NF_CONNTRACK_EVENTS

Connection tracking events

If this option is enabled, the connection tracking code will
provide a notifier chain that can be used by other kernel code
to get notified about changes in the connection tracking state.

If unsure, say `N'.

NF_CONNTRACK_TIMESTAMP

'Connection tracking timestamping'

This option enables support for connection tracking timestamping.
This allows you to store the flow start-time and to obtain
the flow-stop time (once it has been destroyed) via Connection
tracking events.

If unsure, say `N'.

NF_CT_PROTO_DCCP

'DCCP protocol connection tracking support (EXPERIMENTAL)'

With this option enabled, the layer 3 independent connection
tracking code will be able to do state tracking on DCCP connections.

If unsure, say 'N'.

NF_CT_PROTO_SCTP

'SCTP protocol connection tracking support (EXPERIMENTAL)'

With this option enabled, the layer 3 independent connection
tracking code will be able to do state tracking on SCTP connections.

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NF_CT_PROTO_UDPLITE

'UDP-Lite protocol connection tracking support'

With this option enabled, the layer 3 independent connection
tracking code will be able to do state tracking on UDP-Lite
connections.

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_AMANDA

Amanda backup protocol support

If you are running the Amanda backup package <http://www.amanda.org/>
on this machine or machines that will be MASQUERADED through this
machine, then you may want to enable this feature.  This allows the
connection tracking and natting code to allow the sub-channels that
Amanda requires for communication of the backup data, messages and
index.

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_FTP

FTP protocol support

Tracking FTP connections is problematic: special helpers are
required for tracking them, and doing masquerading and other forms
of Network Address Translation on them.

This is FTP support on Layer 3 independent connection tracking.
Layer 3 independent connection tracking is experimental scheme
which generalize ip_conntrack to support other layer 3 protocols.

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_H323

H.323 protocol support

H.323 is a VoIP signalling protocol from ITU-T. As one of the most
important VoIP protocols, it is widely used by voice hardware and
software including voice gateways, IP phones, Netmeeting, OpenPhone,
Gnomemeeting, etc.

With this module you can support H.323 on a connection tracking/NAT
firewall.

This module supports RAS, Fast Start, H.245 Tunnelling, Call
Forwarding, RTP/RTCP and T.120 based audio, video, fax, chat,
whiteboard, file transfer, etc. For more information, please
visit http://nath323.sourceforge.net/.

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_IRC

IRC protocol support

There is a commonly-used extension to IRC called
Direct Client-to-Client Protocol (DCC).  This enables users to send
files to each other, and also chat to each other without the need
of a server.  DCC Sending is used anywhere you send files over IRC,
and DCC Chat is most commonly used by Eggdrop bots.  If you are
using NAT, this extension will enable you to send files and initiate
chats.  Note that you do NOT need this extension to get files or
have others initiate chats, or everything else in IRC.

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_NETBIOS_NS

NetBIOS name service protocol support

NetBIOS name service requests are sent as broadcast messages from an
unprivileged port and responded to with unicast messages to the
same port. This make them hard to firewall properly because connection
tracking doesn't deal with broadcasts. This helper tracks locally
originating NetBIOS name service requests and the corresponding
responses. It relies on correct IP address configuration, specifically
netmask and broadcast address. When properly configured, the output
of "ip address show" should look similar to this:

$ ip -4 address show eth0
4: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
inet 172.16.2.252/24 brd 172.16.2.255 scope global eth0

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_SNMP

SNMP service protocol support

SNMP service requests are sent as broadcast messages from an
unprivileged port and responded to with unicast messages to the
same port. This make them hard to firewall properly because connection
tracking doesn't deal with broadcasts. This helper tracks locally
originating SNMP service requests and the corresponding
responses. It relies on correct IP address configuration, specifically
netmask and broadcast address.

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_PPTP

PPtP protocol support

This module adds support for PPTP (Point to Point Tunnelling
Protocol, RFC2637) connection tracking and NAT.

If you are running PPTP sessions over a stateful firewall or NAT
box, you may want to enable this feature.

Please note that not all PPTP modes of operation are supported yet.
Specifically these limitations exist:
- Blindly assumes that control connections are always established
in PNS->PAC direction. This is a violation of RFC2637.
- Only supports a single call within each session

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_SANE

SANE protocol support (EXPERIMENTAL)

SANE is a protocol for remote access to scanners as implemented
by the 'saned' daemon. Like FTP, it uses separate control and
data connections.

With this module you can support SANE on a connection tracking
firewall.

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_SIP

SIP protocol support

SIP is an application-layer control protocol that can establish,
modify, and terminate multimedia sessions (conferences) such as
Internet telephony calls. With the ip_conntrack_sip and
the nf_nat_sip modules you can support the protocol on a connection
tracking/NATing firewall.

To compile it as a module, choose M here.  If unsure, say N.

NF_CONNTRACK_TFTP

TFTP protocol support

TFTP connection tracking helper, this is required depending
on how restrictive your ruleset is.
If you are using a tftp client behind -j SNAT or -j MASQUERADING
you will need this.

To compile it as a module, choose M here.  If unsure, say N.

NF_CT_NETLINK

'Connection tracking netlink interface'

This option enables support for a netlink-based userspace interface

NETFILTER_TPROXY

Transparent proxying support (EXPERIMENTAL)

This option enables transparent proxying support, that is,
support for handling non-locally bound IPv4 TCP and UDP sockets.
For it to work you will have to configure certain iptables rules
and use policy routing. For more information on how to set it up
see Documentation/networking/tproxy.txt.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XTABLES

Netfilter Xtables support (required for ip_tables)

This is required if you intend to use any of ip_tables,
ip6_tables or arp_tables.

Xtables combined modules

NETFILTER_XT_MARK

'nfmark target and match support'

This option adds the "MARK" target and "mark" match.

Netfilter mark matching allows you to match packets based on the
"nfmark" value in the packet.
The target allows you to create rules in the "mangle" table which alter
the netfilter mark (nfmark) field associated with the packet.

Prior to routing, the nfmark can influence the routing method (see
"Use netfilter MARK value as routing key") and can also be used by
other subsystems to change their behavior.

NETFILTER_XT_CONNMARK

'ctmark target and match support'

This option adds the "CONNMARK" target and "connmark" match.

Netfilter allows you to store a mark value per connection (a.k.a.
ctmark), similarly to the packet mark (nfmark). Using this
target and match, you can set and match on this mark.

NETFILTER_XT_SET

'set target and match support'

This option adds the "SET" target and "set" match.

Using this target and match, you can add/delete and match
elements in the sets created by ipset(8).

To compile it as a module, choose M here.  If unsure, say N.

Xtables targets

NETFILTER_XT_TARGET_AUDIT

AUDIT target support

This option adds a 'AUDIT' target, which can be used to create
audit records for packets dropped/accepted.

To compileit as a module, choose M here. If unsure, say N.

NETFILTER_XT_TARGET_CHECKSUM

CHECKSUM target support

This option adds a `CHECKSUM' target, which can be used in the iptables mangle
table.

You can use this target to compute and fill in the checksum in
a packet that lacks a checksum.  This is particularly useful,
if you need to work around old applications such as dhcp clients,
that do not work well with checksum offloads, but don't want to disable
checksum offload in your device.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_CLASSIFY

'"CLASSIFY" target support'

This option adds a `CLASSIFY' target, which enables the user to set
the priority of a packet. Some qdiscs can use this value for
classification, among these are:

atm, cbq, dsmark, pfifo_fast, htb, prio

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_CONNMARK

'"CONNMARK" target support'

This is a backwards-compat option for the user's convenience
(e.g. when running oldconfig). It selects
CONFIG_NETFILTER_XT_CONNMARK (combined connmark/CONNMARK module).

NETFILTER_XT_TARGET_CONNSECMARK

'"CONNSECMARK" target support'

The CONNSECMARK target copies security markings from packets
to connections, and restores security markings from connections
to packets (if the packets are not already marked).  This would
normally be used in conjunction with the SECMARK target.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_CT

'"CT" target support'

This options adds a `CT' target, which allows to specify initial
connection tracking parameters like events to be delivered and
the helper to be used.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_DSCP

'"DSCP" and "TOS" target support'

This option adds a `DSCP' target, which allows you to manipulate
the IPv4/IPv6 header DSCP field (differentiated services codepoint).

The DSCP field can have any value between 0x0 and 0x3f inclusive.

It also adds the "TOS" target, which allows you to create rules in
the "mangle" table which alter the Type Of Service field of an IPv4
or the Priority field of an IPv6 packet, prior to routing.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_HL

'"HL" hoplimit target support'

This option adds the "HL" (for IPv6) and "TTL" (for IPv4)
targets, which enable the user to change the
hoplimit/time-to-live value of the IP header.

While it is safe to decrement the hoplimit/TTL value, the
modules also allow to increment and set the hoplimit value of
the header to arbitrary values. This is EXTREMELY DANGEROUS
since you can easily create immortal packets that loop
forever on the network.

NETFILTER_XT_TARGET_IDLETIMER

IDLETIMER target support

This option adds the `IDLETIMER' target.  Each matching packet
resets the timer associated with label specified when the rule is
added.  When the timer expires, it triggers a sysfs notification.
The remaining time for expiration can be read via sysfs.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_LED

'"LED" target support'

This option adds a `LED' target, which allows you to blink LEDs in
response to particular packets passing through your machine.

This can be used to turn a spare LED into a network activity LED,
which only flashes in response to FTP transfers, for example.  Or
you could have an LED which lights up for a minute or two every time
somebody connects to your machine via SSH.

You will need support for the "led" class to make this work.

To create an LED trigger for incoming SSH traffic:
iptables -A INPUT -p tcp --dport 22 -j LED --led-trigger-id ssh --led-delay 1000

Then attach the new trigger to an LED on your system:
echo netfilter-ssh > /sys/class/leds/<ledname>/trigger

For more information on the LEDs available on your system, see
Documentation/leds-class.txt

NETFILTER_XT_TARGET_MARK

'"MARK" target support'

This is a backwards-compat option for the user's convenience
(e.g. when running oldconfig). It selects
CONFIG_NETFILTER_XT_MARK (combined mark/MARK module).

NETFILTER_XT_TARGET_NFLOG

'"NFLOG" target support'

This option enables the NFLOG target, which allows to LOG
messages through nfnetlink_log.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_NFQUEUE

'"NFQUEUE" target Support'

This target replaced the old obsolete QUEUE target.

As opposed to QUEUE, it supports 65535 different queues,
not just one.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_NOTRACK

'"NOTRACK" target support'

The NOTRACK target allows a select rule to specify
which packets *not* to enter the conntrack/NAT
subsystem with all the consequences (no ICMP error tracking,
no protocol helpers for the selected packets).

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NETFILTER_XT_TARGET_RATEEST

'"RATEEST" target support'

This option adds a `RATEEST' target, which allows to measure
rates similar to TC estimators. The `rateest' match can be
used to match on the measured rates.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_TEE

'"TEE" - packet cloning to alternate destination'

This option adds a "TEE" target with which a packet can be cloned and
this clone be rerouted to another nexthop.

NETFILTER_XT_TARGET_TPROXY

'"TPROXY" target support (EXPERIMENTAL)'

This option adds a `TPROXY' target, which is somewhat similar to
REDIRECT.  It can only be used in the mangle table and is useful
to redirect traffic to a transparent proxy.  It does _not_ depend
on Netfilter connection tracking and NAT, unlike REDIRECT.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_TRACE

'"TRACE" target support'

The TRACE target allows you to mark packets so that the kernel
will log every rule which match the packets as those traverse
the tables, chains, rules.

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NETFILTER_XT_TARGET_SECMARK

'"SECMARK" target support'

The SECMARK target allows security marking of network
packets, for use with security subsystems.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_TCPMSS

'"TCPMSS" target support'

This option adds a `TCPMSS' target, which allows you to alter the
MSS value of TCP SYN packets, to control the maximum size for that
connection (usually limiting it to your outgoing interface's MTU
minus 40).

This is used to overcome criminally braindead ISPs or servers which
block ICMP Fragmentation Needed packets.  The symptoms of this
problem are that everything works fine from your Linux
firewall/router, but machines behind it can never exchange large
packets:
1) Web browsers connect, then hang with no data received.
2) Small mail works fine, but large emails hang.
3) ssh works fine, but scp hangs after initial handshaking.

Workaround: activate this option and add a rule to your firewall
configuration like:

iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN \
-j TCPMSS --clamp-mss-to-pmtu

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_TARGET_TCPOPTSTRIP

'"TCPOPTSTRIP" target support (EXPERIMENTAL)'

This option adds a "TCPOPTSTRIP" target, which allows you to strip
TCP options from TCP packets.

Xtables matches

NETFILTER_XT_MATCH_ADDRTYPE

'"addrtype" address type match support'

This option allows you to match what routing thinks of an address,
eg. UNICAST, LOCAL, BROADCAST, ...

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NETFILTER_XT_MATCH_CLUSTER

'"cluster" match support'

This option allows you to build work-load-sharing clusters of
network servers/stateful firewalls without having a dedicated
load-balancing router/server/switch. Basically, this match returns
true when the packet must be handled by this cluster node. Thus,
all nodes see all packets and this match decides which node handles
what packets. The work-load sharing algorithm is based on source
address hashing.

If you say Y or M here, try `iptables -m cluster --help` for
more information.

NETFILTER_XT_MATCH_COMMENT

'"comment" match support'

This option adds a `comment' dummy-match, which allows you to put
comments in your iptables ruleset.

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NETFILTER_XT_MATCH_CONNBYTES

'"connbytes" per-connection counter match support'

This option adds a `connbytes' match, which allows you to match the
number of bytes and/or packets for each direction within a connection.

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NETFILTER_XT_MATCH_CONNLIMIT

'"connlimit" match support"'

This match allows you to match against the number of parallel
connections to a server per client IP address (or address block).

NETFILTER_XT_MATCH_CONNMARK

'"connmark" connection mark match support'

This is a backwards-compat option for the user's convenience
(e.g. when running oldconfig). It selects
CONFIG_NETFILTER_XT_CONNMARK (combined connmark/CONNMARK module).

NETFILTER_XT_MATCH_CONNTRACK

'"conntrack" connection tracking match support'

This is a general conntrack match module, a superset of the state match.

It allows matching on additional conntrack information, which is
useful in complex configurations, such as NAT gateways with multiple
internet links or tunnels.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_CPU

'"cpu" match support'

CPU matching allows you to match packets based on the CPU
currently handling the packet.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_DCCP

'"dccp" protocol match support'

With this option enabled, you will be able to use the iptables
`dccp' match in order to match on DCCP source/destination ports
and DCCP flags.

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NETFILTER_XT_MATCH_DEVGROUP

'"devgroup" match support'

This options adds a `devgroup' match, which allows to match on the
device group a network device is assigned to.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_DSCP

'"dscp" and "tos" match support'

This option adds a `DSCP' match, which allows you to match against
the IPv4/IPv6 header DSCP field (differentiated services codepoint).

The DSCP field can have any value between 0x0 and 0x3f inclusive.

It will also add a "tos" match, which allows you to match packets
based on the Type Of Service fields of the IPv4 packet (which share
the same bits as DSCP).

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_ESP

'"esp" match support'

This match extension allows you to match a range of SPIs
inside ESP header of IPSec packets.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_HASHLIMIT

'"hashlimit" match support'

This option adds a `hashlimit' match.

As opposed to `limit', this match dynamically creates a hash table
of limit buckets, based on your selection of source/destination
addresses and/or ports.

It enables you to express policies like `10kpps for any given
destination address' or `500pps from any given source address'
with a single rule.

NETFILTER_XT_MATCH_HELPER

'"helper" match support'

Helper matching allows you to match packets in dynamic connections
tracked by a conntrack-helper, ie. ip_conntrack_ftp

To compile it as a module, choose M here.  If unsure, say Y.

NETFILTER_XT_MATCH_HL

'"hl" hoplimit/TTL match support'

HL matching allows you to match packets based on the hoplimit
in the IPv6 header, or the time-to-live field in the IPv4
header of the packet.

NETFILTER_XT_MATCH_IPRANGE

'"iprange" address range match support'

This option adds a "iprange" match, which allows you to match based on
an IP address range. (Normal iptables only matches on single addresses
with an optional mask.)

If unsure, say M.

NETFILTER_XT_MATCH_IPVS

'"ipvs" match support'

This option allows you to match against IPVS properties of a packet.

If unsure, say N.

NETFILTER_XT_MATCH_LENGTH

'"length" match support'

This option allows you to match the length of a packet against a
specific value or range of values.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_LIMIT

'"limit" match support'

limit matching allows you to control the rate at which a rule can be
matched: mainly useful in combination with the LOG target ("LOG
target support", below) and to avoid some Denial of Service attacks.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_MAC

'"mac" address match support'

MAC matching allows you to match packets based on the source
Ethernet address of the packet.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_MARK

'"mark" match support'

This is a backwards-compat option for the user's convenience
(e.g. when running oldconfig). It selects
CONFIG_NETFILTER_XT_MARK (combined mark/MARK module).

NETFILTER_XT_MATCH_MULTIPORT

'"multiport" Multiple port match support'

Multiport matching allows you to match TCP or UDP packets based on
a series of source or destination ports: normally a rule can only
match a single range of ports.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_OSF

'"osf" Passive OS fingerprint match'

This option selects the Passive OS Fingerprinting match module
that allows to passively match the remote operating system by
analyzing incoming TCP SYN packets.

Rules and loading software can be downloaded from
http://www.ioremap.net/projects/osf

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_OWNER

'"owner" match support'

Socket owner matching allows you to match locally-generated packets
based on who created the socket: the user or group. It is also
possible to check whether a socket actually exists.

NETFILTER_XT_MATCH_POLICY

'IPsec "policy" match support'

Policy matching allows you to match packets based on the
IPsec policy that was used during decapsulation/will
be used during encapsulation.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_PHYSDEV

'"physdev" match support'

Physdev packet matching matches against the physical bridge ports
the IP packet arrived on or will leave by.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_PKTTYPE

'"pkttype" packet type match support'

Packet type matching allows you to match a packet by
its "class", eg. BROADCAST, MULTICAST, ...

Typical usage:
iptables -A INPUT -m pkttype --pkt-type broadcast -j LOG

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_QUOTA

'"quota" match support'

This option adds a `quota' match, which allows to match on a
byte counter.

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NETFILTER_XT_MATCH_RATEEST

'"rateest" match support'

This option adds a `rateest' match, which allows to match on the
rate estimated by the RATEEST target.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_REALM

'"realm" match support'

This option adds a `realm' match, which allows you to use the realm
key from the routing subsystem inside iptables.

This match pretty much resembles the CONFIG_NET_CLS_ROUTE4 option
in tc world.

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NETFILTER_XT_MATCH_RECENT

'"recent" match support'

This match is used for creating one or many lists of recently
used addresses and then matching against that/those list(s).

Short options are available by using 'iptables -m recent -h'
Official Website: <http://snowman.net/projects/ipt_recent/>

NETFILTER_XT_MATCH_SCTP

'"sctp" protocol match support (EXPERIMENTAL)'

With this option enabled, you will be able to use the
`sctp' match in order to match on SCTP source/destination ports
and SCTP chunk types.

If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.

NETFILTER_XT_MATCH_SOCKET

'"socket" match support (EXPERIMENTAL)'

This option adds a `socket' match, which can be used to match
packets for which a TCP or UDP socket lookup finds a valid socket.
It can be used in combination with the MARK target and policy
routing to implement full featured non-locally bound sockets.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_STATE

'"state" match support'

Connection state matching allows you to match packets based on their
relationship to a tracked connection (ie. previous packets).  This
is a powerful tool for packet classification.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_STATISTIC

'"statistic" match support'

This option adds a `statistic' match, which allows you to match
on packets periodically or randomly with a given percentage.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_STRING

'"string" match support'

This option adds a `string' match, which allows you to look for
pattern matchings in packets.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_TCPMSS

'"tcpmss" match support'

This option adds a `tcpmss' match, which allows you to examine the
MSS value of TCP SYN packets, which control the maximum packet size
for that connection.

To compile it as a module, choose M here.  If unsure, say N.

NETFILTER_XT_MATCH_TIME

'"time" match support'

This option adds a "time" match, which allows you to match based on
the packet arrival time (at the machine which netfilter is running)
on) or departure time/date (for locally generated packets).

If you say Y here, try `iptables -m time --help` for
more information.

If you want to compile it as a module, say M here.
If unsure, say N.

NETFILTER_XT_MATCH_U32

'"u32" match support'

u32 allows you to extract quantities of up to 4 bytes from a packet,
AND them with specified masks, shift them by specified amounts and
test whether the results are in any of a set of specified ranges.
The specification of what to extract is general enough to skip over
headers with lengths stored in the packet, as in IP or TCP header
lengths.

Details and examples are in the kernel module source.


net/netfilter/ipset/Kconfig

net/netfilter/ipvs/Kconfig