xref: /openbmc/linux/net/ipv4/netfilter/Kconfig (revision 1da177e4)

#
# IP netfilter configuration
#

menu "IP: Netfilter Configuration"
	depends on INET && NETFILTER

# connection tracking, helpers and protocols
config IP_NF_CONNTRACK
	tristate "Connection tracking (required for masq/NAT)"
	---help---
	  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 (except for Fast NAT).  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.

config IP_NF_CT_ACCT
	bool "Connection tracking flow accounting"
	depends on IP_NF_CONNTRACK
	help
	  If this option is enabled, the connection tracking code will
	  keep per-flow packet and byte counters.

	  Those counters can be used for flow-based accounting or the
	  `connbytes' match.

	  If unsure, say `N'.

config IP_NF_CONNTRACK_MARK
	bool  'Connection mark tracking support'
	help
	  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.

config IP_NF_CT_PROTO_SCTP
	tristate  'SCTP protocol connection tracking support (EXPERIMENTAL)'
	depends on IP_NF_CONNTRACK && EXPERIMENTAL
	help
	  With this option enabled, the 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/modules.txt>.  If unsure, say `N'.

config IP_NF_FTP
	tristate "FTP protocol support"
	depends on IP_NF_CONNTRACK
	help
	  Tracking FTP connections is problematic: special helpers are
	  required for tracking them, and doing masquerading and other forms
	  of Network Address Translation on them.

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

config IP_NF_IRC
	tristate "IRC protocol support"
	depends on IP_NF_CONNTRACK
	---help---
	  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 Y.

config IP_NF_TFTP
	tristate "TFTP protocol support"
	depends on IP_NF_CONNTRACK
	help
	  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 Y.

config IP_NF_AMANDA
	tristate "Amanda backup protocol support"
	depends on IP_NF_CONNTRACK
	help
	  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 Y.

config IP_NF_QUEUE
	tristate "Userspace queueing via NETLINK"
	help
	  Netfilter has the ability to queue packets to user space: the
	  netlink device can be used to access them using this driver.

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

config IP_NF_IPTABLES
	tristate "IP tables support (required for filtering/masq/NAT)"
	help
	  iptables is a general, extensible packet identification framework.
	  The packet filtering and full NAT (masquerading, port forwarding,
	  etc) subsystems now use this: say `Y' or `M' here if you want to use
	  either of those.

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

# The matches.
config IP_NF_MATCH_LIMIT
	tristate "limit match support"
	depends on IP_NF_IPTABLES
	help
	  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.

config IP_NF_MATCH_IPRANGE
	tristate "IP range match support"
	depends on IP_NF_IPTABLES
	help
	  This option makes possible to match IP addresses against IP address
	  ranges.

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

config IP_NF_MATCH_MAC
	tristate "MAC address match support"
	depends on IP_NF_IPTABLES
	help
	  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.

config IP_NF_MATCH_PKTTYPE
	tristate "Packet type match support"
	depends on IP_NF_IPTABLES
	help
         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.

config IP_NF_MATCH_MARK
	tristate "netfilter MARK match support"
	depends on IP_NF_IPTABLES
	help
	  Netfilter mark matching allows you to match packets based on the
	  `nfmark' value in the packet.  This can be set by the MARK target
	  (see below).

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

config IP_NF_MATCH_MULTIPORT
	tristate "Multiple port match support"
	depends on IP_NF_IPTABLES
	help
	  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.

config IP_NF_MATCH_TOS
	tristate "TOS match support"
	depends on IP_NF_IPTABLES
	help
	  TOS matching allows you to match packets based on the Type Of
	  Service fields of the IP packet.

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

config IP_NF_MATCH_RECENT
	tristate "recent match support"
	depends on IP_NF_IPTABLES
	help
	  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/>

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

config IP_NF_MATCH_ECN
	tristate "ECN match support"
	depends on IP_NF_IPTABLES
	help
	  This option adds a `ECN' match, which allows you to match against
	  the IPv4 and TCP header ECN fields.

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

config IP_NF_MATCH_DSCP
	tristate "DSCP match support"
	depends on IP_NF_IPTABLES
	help
	  This option adds a `DSCP' match, which allows you to match against
	  the IPv4 header DSCP field (DSCP codepoint).

	  The DSCP codepoint can have any value between 0x0 and 0x4f.

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

config IP_NF_MATCH_AH_ESP
	tristate "AH/ESP match support"
	depends on IP_NF_IPTABLES
	help
	  These two match extensions (`ah' and `esp') allow you to match a
	  range of SPIs inside AH or ESP headers of IPSec packets.

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

config IP_NF_MATCH_LENGTH
	tristate "LENGTH match support"
	depends on IP_NF_IPTABLES
	help
	  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.

config IP_NF_MATCH_TTL
	tristate "TTL match support"
	depends on IP_NF_IPTABLES
	help
	  This adds CONFIG_IP_NF_MATCH_TTL option, which enabled the user
	  to match packets by their TTL value.

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

config IP_NF_MATCH_TCPMSS
	tristate "tcpmss match support"
	depends on IP_NF_IPTABLES
	help
	  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.

config IP_NF_MATCH_HELPER
	tristate "Helper match support"
	depends on IP_NF_CONNTRACK && IP_NF_IPTABLES
	help
	  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.

config IP_NF_MATCH_STATE
	tristate "Connection state match support"
	depends on IP_NF_CONNTRACK && IP_NF_IPTABLES
	help
	  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.

config IP_NF_MATCH_CONNTRACK
	tristate "Connection tracking match support"
	depends on IP_NF_CONNTRACK && IP_NF_IPTABLES
	help
	  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.

config IP_NF_MATCH_OWNER
	tristate "Owner match support"
	depends on IP_NF_IPTABLES
	help
	  Packet owner matching allows you to match locally-generated packets
	  based on who created them: the user, group, process or session.

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

config IP_NF_MATCH_PHYSDEV
	tristate "Physdev match support"
	depends on IP_NF_IPTABLES && BRIDGE_NETFILTER
	help
	  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.

config IP_NF_MATCH_ADDRTYPE
	tristate  'address type match support'
	depends on IP_NF_IPTABLES
	help
	  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/modules.txt>.  If unsure, say `N'.

config IP_NF_MATCH_REALM
	tristate  'realm match support'
	depends on IP_NF_IPTABLES
	select NET_CLS_ROUTE
	help
	  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/modules.txt>.  If unsure, say `N'.

config IP_NF_MATCH_SCTP
	tristate  'SCTP protocol match support'
	depends on IP_NF_IPTABLES
	help
	  With this option enabled, you will be able to use the iptables
	  `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/modules.txt>.  If unsure, say `N'.

config IP_NF_MATCH_COMMENT
	tristate  'comment match support'
	depends on IP_NF_IPTABLES
	help
	  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/modules.txt>.  If unsure, say `N'.

config IP_NF_MATCH_CONNMARK
	tristate  'Connection mark match support'
	depends on IP_NF_CONNTRACK_MARK && IP_NF_IPTABLES
	help
	  This option adds a `connmark' match, which allows you to match the
	  connection mark value previously set for the session by `CONNMARK'.

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

config IP_NF_MATCH_HASHLIMIT
	tristate  'hashlimit match support'
	depends on IP_NF_IPTABLES
	help
	  This option adds a new iptables `hashlimit' match.

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

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

# `filter', generic and specific targets
config IP_NF_FILTER
	tristate "Packet filtering"
	depends on IP_NF_IPTABLES
	help
	  Packet filtering defines a table `filter', which has a series of
	  rules for simple packet filtering at local input, forwarding and
	  local output.  See the man page for iptables(8).

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

config IP_NF_TARGET_REJECT
	tristate "REJECT target support"
	depends on IP_NF_FILTER
	help
	  The REJECT target allows a filtering rule to specify that an ICMP
	  error should be issued in response to an incoming packet, rather
	  than silently being dropped.

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

config IP_NF_TARGET_LOG
	tristate "LOG target support"
	depends on IP_NF_IPTABLES
	help
	  This option adds a `LOG' target, which allows you to create rules in
	  any iptables table which records the packet header to the syslog.

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

config IP_NF_TARGET_ULOG
	tristate "ULOG target support"
	depends on IP_NF_IPTABLES
	---help---
	  This option adds a `ULOG' target, which allows you to create rules in
	  any iptables table. The packet is passed to a userspace logging
	  daemon using netlink multicast sockets; unlike the LOG target
	  which can only be viewed through syslog.

	  The apropriate userspace logging daemon (ulogd) may be obtained from
	  <http://www.gnumonks.org/projects/ulogd/>

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

config IP_NF_TARGET_TCPMSS
	tristate "TCPMSS target support"
	depends on IP_NF_IPTABLES
	---help---
	  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.

# NAT + specific targets
config IP_NF_NAT
	tristate "Full NAT"
	depends on IP_NF_IPTABLES && IP_NF_CONNTRACK
	help
	  The Full NAT option allows masquerading, port forwarding and other
	  forms of full Network Address Port Translation.  It is controlled by
	  the `nat' table in iptables: see the man page for iptables(8).

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

config IP_NF_NAT_NEEDED
	bool
	depends on IP_NF_NAT != n
	default y

config IP_NF_TARGET_MASQUERADE
	tristate "MASQUERADE target support"
	depends on IP_NF_NAT
	help
	  Masquerading is a special case of NAT: all outgoing connections are
	  changed to seem to come from a particular interface's address, and
	  if the interface goes down, those connections are lost.  This is
	  only useful for dialup accounts with dynamic IP address (ie. your IP
	  address will be different on next dialup).

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

config IP_NF_TARGET_REDIRECT
	tristate "REDIRECT target support"
	depends on IP_NF_NAT
	help
	  REDIRECT is a special case of NAT: all incoming connections are
	  mapped onto the incoming interface's address, causing the packets to
	  come to the local machine instead of passing through.  This is
	  useful for transparent proxies.

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

config IP_NF_TARGET_NETMAP
	tristate "NETMAP target support"
	depends on IP_NF_NAT
	help
	  NETMAP is an implementation of static 1:1 NAT mapping of network
	  addresses. It maps the network address part, while keeping the host
	  address part intact. It is similar to Fast NAT, except that
	  Netfilter's connection tracking doesn't work well with Fast NAT.

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

config IP_NF_TARGET_SAME
	tristate "SAME target support"
	depends on IP_NF_NAT
	help
	  This option adds a `SAME' target, which works like the standard SNAT
	  target, but attempts to give clients the same IP for all connections.

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

config IP_NF_NAT_SNMP_BASIC
	tristate "Basic SNMP-ALG support (EXPERIMENTAL)"
	depends on EXPERIMENTAL && IP_NF_NAT
	---help---

	  This module implements an Application Layer Gateway (ALG) for
	  SNMP payloads.  In conjunction with NAT, it allows a network
	  management system to access multiple private networks with
	  conflicting addresses.  It works by modifying IP addresses
	  inside SNMP payloads to match IP-layer NAT mapping.

	  This is the "basic" form of SNMP-ALG, as described in RFC 2962

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

config IP_NF_NAT_IRC
	tristate
	depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
	default IP_NF_NAT if IP_NF_IRC=y
	default m if IP_NF_IRC=m

# If they want FTP, set to $CONFIG_IP_NF_NAT (m or y),
# or $CONFIG_IP_NF_FTP (m or y), whichever is weaker.  Argh.
config IP_NF_NAT_FTP
	tristate
	depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
	default IP_NF_NAT if IP_NF_FTP=y
	default m if IP_NF_FTP=m

config IP_NF_NAT_TFTP
	tristate
	depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
	default IP_NF_NAT if IP_NF_TFTP=y
	default m if IP_NF_TFTP=m

config IP_NF_NAT_AMANDA
	tristate
	depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
	default IP_NF_NAT if IP_NF_AMANDA=y
	default m if IP_NF_AMANDA=m

# mangle + specific targets
config IP_NF_MANGLE
	tristate "Packet mangling"
	depends on IP_NF_IPTABLES
	help
	  This option adds a `mangle' table to iptables: see the man page for
	  iptables(8).  This table is used for various packet alterations
	  which can effect how the packet is routed.

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

config IP_NF_TARGET_TOS
	tristate "TOS target support"
	depends on IP_NF_MANGLE
	help
	  This option adds a `TOS' target, which allows you to create rules in
	  the `mangle' table which alter the Type Of Service field of an IP
	  packet prior to routing.

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

config IP_NF_TARGET_ECN
	tristate "ECN target support"
	depends on IP_NF_MANGLE
	---help---
	  This option adds a `ECN' target, which can be used in the iptables mangle
	  table.

	  You can use this target to remove the ECN bits from the IPv4 header of
	  an IP packet.  This is particularly useful, if you need to work around
	  existing ECN blackholes on the internet, but don't want to disable
	  ECN support in general.

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

config IP_NF_TARGET_DSCP
	tristate "DSCP target support"
	depends on IP_NF_MANGLE
	help
	  This option adds a `DSCP' match, which allows you to match against
	  the IPv4 header DSCP field (DSCP codepoint).

	  The DSCP codepoint can have any value between 0x0 and 0x4f.

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

config IP_NF_TARGET_MARK
	tristate "MARK target support"
	depends on IP_NF_MANGLE
	help
	  This option adds a `MARK' target, which allows you to create rules
	  in the `mangle' table which alter the netfilter mark (nfmark) field
	  associated with the packet prior to routing. This can change
	  the routing method (see `Use netfilter MARK value as routing
	  key') and can also be used by other subsystems to change their
	  behavior.

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

config IP_NF_TARGET_CLASSIFY
	tristate "CLASSIFY target support"
	depends on IP_NF_MANGLE
	help
	  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.

config IP_NF_TARGET_CONNMARK
	tristate  'CONNMARK target support'
	depends on IP_NF_CONNTRACK_MARK && IP_NF_MANGLE
	help
	  This option adds a `CONNMARK' target, which allows one to manipulate
	  the connection mark value.  Similar to the MARK target, but
	  affects the connection mark value rather than the packet mark value.

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

config IP_NF_TARGET_CLUSTERIP
	tristate "CLUSTERIP target support (EXPERIMENTAL)"
	depends on IP_NF_CONNTRACK_MARK && IP_NF_IPTABLES && EXPERIMENTAL
	help
	  The CLUSTERIP target allows you to build load-balancing clusters of
	  network servers without having a dedicated load-balancing
	  router/server/switch.

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

# raw + specific targets
config IP_NF_RAW
	tristate  'raw table support (required for NOTRACK/TRACE)'
	depends on IP_NF_IPTABLES
	help
	  This option adds a `raw' table to iptables. This table is the very
	  first in the netfilter framework and hooks in at the PREROUTING
	  and OUTPUT chains.

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

config IP_NF_TARGET_NOTRACK
	tristate  'NOTRACK target support'
	depends on IP_NF_RAW
	depends on IP_NF_CONNTRACK
	help
	  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/modules.txt>.  If unsure, say `N'.


# ARP tables
config IP_NF_ARPTABLES
	tristate "ARP tables support"
	help
	  arptables is a general, extensible packet identification framework.
	  The ARP packet filtering and mangling (manipulation)subsystems
	  use this: say Y or M here if you want to use either of those.

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

config IP_NF_ARPFILTER
	tristate "ARP packet filtering"
	depends on IP_NF_ARPTABLES
	help
	  ARP packet filtering defines a table `filter', which has a series of
	  rules for simple ARP packet filtering at local input and
	  local output.  On a bridge, you can also specify filtering rules
	  for forwarded ARP packets. See the man page for arptables(8).

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

config IP_NF_ARP_MANGLE
	tristate "ARP payload mangling"
	depends on IP_NF_ARPTABLES
	help
	  Allows altering the ARP packet payload: source and destination
	  hardware and network addresses.

endmenu