net/ipv4/netfilter/Kconfig

   1 #
   2 # IP netfilter configuration
   3 #
   4
   5 menu "IP: Netfilter Configuration"
   6         depends on INET && NETFILTER
   7
   8 config NF_CONNTRACK_IPV4
   9         tristate "IPv4 support for new connection tracking (EXPERIMENTAL)"
  10         depends on EXPERIMENTAL && NF_CONNTRACK
  11         ---help---
  12           Connection tracking keeps a record of what packets have passed
  13           through your machine, in order to figure out how they are related
  14           into connections.
  15
  16           This is IPv4 support on Layer 3 independent connection tracking.
  17           Layer 3 independent connection tracking is experimental scheme
  18           which generalize ip_conntrack to support other layer 3 protocols.
  19
  20           To compile it as a module, choose M here.  If unsure, say N.
  21
  22 # connection tracking, helpers and protocols
  23 config IP_NF_CONNTRACK
  24         tristate "Connection tracking (required for masq/NAT)"
  25         ---help---
  26           Connection tracking keeps a record of what packets have passed
  27           through your machine, in order to figure out how they are related
  28           into connections.
  29
  30           This is required to do Masquerading or other kinds of Network
  31           Address Translation (except for Fast NAT).  It can also be used to
  32           enhance packet filtering (see `Connection state match support'
  33           below).
  34
  35           To compile it as a module, choose M here.  If unsure, say N.
  36
  37 config IP_NF_CT_ACCT
  38         bool "Connection tracking flow accounting"
  39         depends on IP_NF_CONNTRACK
  40         help
  41           If this option is enabled, the connection tracking code will
  42           keep per-flow packet and byte counters.
  43
  44           Those counters can be used for flow-based accounting or the
  45           `connbytes' match.
  46
  47           If unsure, say `N'.
  48
  49 config IP_NF_CONNTRACK_MARK
  50         bool  'Connection mark tracking support'
  51         depends on IP_NF_CONNTRACK
  52         help
  53           This option enables support for connection marks, used by the
  54           `CONNMARK' target and `connmark' match. Similar to the mark value
  55           of packets, but this mark value is kept in the conntrack session
  56           instead of the individual packets.
  57
  58 config IP_NF_CONNTRACK_SECMARK
  59         bool  'Connection tracking security mark support'
  60         depends on IP_NF_CONNTRACK && NETWORK_SECMARK
  61         help
  62           This option enables security markings to be applied to
  63           connections.  Typically they are copied to connections from
  64           packets using the CONNSECMARK target and copied back from
  65           connections to packets with the same target, with the packets
  66           being originally labeled via SECMARK.
  67
  68           If unsure, say 'N'.
  69
  70 config IP_NF_CONNTRACK_EVENTS
  71         bool "Connection tracking events (EXPERIMENTAL)"
  72         depends on EXPERIMENTAL && IP_NF_CONNTRACK
  73         help
  74           If this option is enabled, the connection tracking code will
  75           provide a notifier chain that can be used by other kernel code
  76           to get notified about changes in the connection tracking state.
  77
  78           IF unsure, say `N'.
  79
  80 config IP_NF_CONNTRACK_NETLINK
  81         tristate 'Connection tracking netlink interface (EXPERIMENTAL)'
  82         depends on EXPERIMENTAL && IP_NF_CONNTRACK && NETFILTER_NETLINK
  83         depends on IP_NF_CONNTRACK!=y || NETFILTER_NETLINK!=m
  84         depends on IP_NF_NAT=n || IP_NF_NAT
  85         help
  86           This option enables support for a netlink-based userspace interface
  87
  88
  89 config IP_NF_CT_PROTO_SCTP
  90         tristate  'SCTP protocol connection tracking support (EXPERIMENTAL)'
  91         depends on IP_NF_CONNTRACK && EXPERIMENTAL
  92         help
  93           With this option enabled, the connection tracking code will
  94           be able to do state tracking on SCTP connections.
  95
  96           If you want to compile it as a module, say M here and read
  97           <file:Documentation/modules.txt>.  If unsure, say `N'.
  98
  99 config IP_NF_FTP
 100         tristate "FTP protocol support"
 101         depends on IP_NF_CONNTRACK
 102         help
 103           Tracking FTP connections is problematic: special helpers are
 104           required for tracking them, and doing masquerading and other forms
 105           of Network Address Translation on them.
 106
 107           To compile it as a module, choose M here.  If unsure, say Y.
 108
 109 config IP_NF_IRC
 110         tristate "IRC protocol support"
 111         depends on IP_NF_CONNTRACK
 112         ---help---
 113           There is a commonly-used extension to IRC called
 114           Direct Client-to-Client Protocol (DCC).  This enables users to send
 115           files to each other, and also chat to each other without the need
 116           of a server.  DCC Sending is used anywhere you send files over IRC,
 117           and DCC Chat is most commonly used by Eggdrop bots.  If you are
 118           using NAT, this extension will enable you to send files and initiate
 119           chats.  Note that you do NOT need this extension to get files or
 120           have others initiate chats, or everything else in IRC.
 121
 122           To compile it as a module, choose M here.  If unsure, say Y.
 123
 124 config IP_NF_NETBIOS_NS
 125         tristate "NetBIOS name service protocol support (EXPERIMENTAL)"
 126         depends on IP_NF_CONNTRACK && EXPERIMENTAL
 127         help
 128           NetBIOS name service requests are sent as broadcast messages from an
 129           unprivileged port and responded to with unicast messages to the
 130           same port. This make them hard to firewall properly because connection
 131           tracking doesn't deal with broadcasts. This helper tracks locally
 132           originating NetBIOS name service requests and the corresponding
 133           responses. It relies on correct IP address configuration, specifically
 134           netmask and broadcast address. When properly configured, the output
 135           of "ip address show" should look similar to this:
 136
 137           $ ip -4 address show eth0
 138           4: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
 139               inet 172.16.2.252/24 brd 172.16.2.255 scope global eth0
 140
 141           To compile it as a module, choose M here.  If unsure, say N.
 142
 143 config IP_NF_TFTP
 144         tristate "TFTP protocol support"
 145         depends on IP_NF_CONNTRACK
 146         help
 147           TFTP connection tracking helper, this is required depending
 148           on how restrictive your ruleset is.
 149           If you are using a tftp client behind -j SNAT or -j MASQUERADING
 150           you will need this.
 151
 152           To compile it as a module, choose M here.  If unsure, say Y.
 153
 154 config IP_NF_AMANDA
 155         tristate "Amanda backup protocol support"
 156         depends on IP_NF_CONNTRACK
 157         select TEXTSEARCH
 158         select TEXTSEARCH_KMP
 159         help
 160           If you are running the Amanda backup package <http://www.amanda.org/>
 161           on this machine or machines that will be MASQUERADED through this
 162           machine, then you may want to enable this feature.  This allows the
 163           connection tracking and natting code to allow the sub-channels that
 164           Amanda requires for communication of the backup data, messages and
 165           index.
 166
 167           To compile it as a module, choose M here.  If unsure, say Y.
 168
 169 config IP_NF_PPTP
 170         tristate  'PPTP protocol support'
 171         depends on IP_NF_CONNTRACK
 172         help
 173           This module adds support for PPTP (Point to Point Tunnelling
 174           Protocol, RFC2637) connection tracking and NAT.
 175
 176           If you are running PPTP sessions over a stateful firewall or NAT
 177           box, you may want to enable this feature.
 178
 179           Please note that not all PPTP modes of operation are supported yet.
 180           For more info, read top of the file
 181           net/ipv4/netfilter/ip_conntrack_pptp.c
 182
 183           If you want to compile it as a module, say M here and read
 184           Documentation/modules.txt.  If unsure, say `N'.
 185
 186 config IP_NF_H323
 187         tristate  'H.323 protocol support (EXPERIMENTAL)'
 188         depends on IP_NF_CONNTRACK && EXPERIMENTAL
 189         help
 190           H.323 is a VoIP signalling protocol from ITU-T. As one of the most
 191           important VoIP protocols, it is widely used by voice hardware and
 192           software including voice gateways, IP phones, Netmeeting, OpenPhone,
 193           Gnomemeeting, etc.
 194
 195           With this module you can support H.323 on a connection tracking/NAT
 196           firewall.
 197
 198           This module supports RAS, Fast Start, H.245 Tunnelling, Call
 199           Forwarding, RTP/RTCP and T.120 based audio, video, fax, chat,
 200           whiteboard, file transfer, etc. For more information, please
 201           visit http://nath323.sourceforge.net/.
 202
 203           If you want to compile it as a module, say 'M' here and read
 204           Documentation/modules.txt.  If unsure, say 'N'.
 205
 206 config IP_NF_SIP
 207         tristate "SIP protocol support (EXPERIMENTAL)"
 208         depends on IP_NF_CONNTRACK && EXPERIMENTAL
 209         help
 210           SIP is an application-layer control protocol that can establish,
 211           modify, and terminate multimedia sessions (conferences) such as
 212           Internet telephony calls. With the ip_conntrack_sip and
 213           the ip_nat_sip modules you can support the protocol on a connection
 214           tracking/NATing firewall.
 215
 216           To compile it as a module, choose M here.  If unsure, say Y.
 217
 218 config IP_NF_QUEUE
 219         tristate "IP Userspace queueing via NETLINK (OBSOLETE)"
 220         help
 221           Netfilter has the ability to queue packets to user space: the
 222           netlink device can be used to access them using this driver.
 223
 224           This option enables the old IPv4-only "ip_queue" implementation
 225           which has been obsoleted by the new "nfnetlink_queue" code (see
 226           CONFIG_NETFILTER_NETLINK_QUEUE).
 227
 228           To compile it as a module, choose M here.  If unsure, say N.
 229
 230 config IP_NF_IPTABLES
 231         tristate "IP tables support (required for filtering/masq/NAT)"
 232         depends on NETFILTER_XTABLES
 233         help
 234           iptables is a general, extensible packet identification framework.
 235           The packet filtering and full NAT (masquerading, port forwarding,
 236           etc) subsystems now use this: say `Y' or `M' here if you want to use
 237           either of those.
 238
 239           To compile it as a module, choose M here.  If unsure, say N.
 240
 241 # The matches.
 242 config IP_NF_MATCH_IPRANGE
 243         tristate "IP range match support"
 244         depends on IP_NF_IPTABLES
 245         help
 246           This option makes possible to match IP addresses against IP address
 247           ranges.
 248
 249           To compile it as a module, choose M here.  If unsure, say N.
 250
 251 config IP_NF_MATCH_TOS
 252         tristate "TOS match support"
 253         depends on IP_NF_IPTABLES
 254         help
 255           TOS matching allows you to match packets based on the Type Of
 256           Service fields of the IP packet.
 257
 258           To compile it as a module, choose M here.  If unsure, say N.
 259
 260 config IP_NF_MATCH_RECENT
 261         tristate "recent match support"
 262         depends on IP_NF_IPTABLES
 263         help
 264           This match is used for creating one or many lists of recently
 265           used addresses and then matching against that/those list(s).
 266
 267           Short options are available by using 'iptables -m recent -h'
 268           Official Website: <http://snowman.net/projects/ipt_recent/>
 269
 270           To compile it as a module, choose M here.  If unsure, say N.
 271
 272 config IP_NF_MATCH_ECN
 273         tristate "ECN match support"
 274         depends on IP_NF_IPTABLES
 275         help
 276           This option adds a `ECN' match, which allows you to match against
 277           the IPv4 and TCP header ECN fields.
 278
 279           To compile it as a module, choose M here.  If unsure, say N.
 280
 281 config IP_NF_MATCH_AH
 282         tristate "AH match support"
 283         depends on IP_NF_IPTABLES
 284         help
 285           This match extension allows you to match a range of SPIs
 286           inside AH header of IPSec packets.
 287
 288           To compile it as a module, choose M here.  If unsure, say N.
 289
 290 config IP_NF_MATCH_TTL
 291         tristate "TTL match support"
 292         depends on IP_NF_IPTABLES
 293         help
 294           This adds CONFIG_IP_NF_MATCH_TTL option, which enabled the user
 295           to match packets by their TTL value.
 296
 297           To compile it as a module, choose M here.  If unsure, say N.
 298
 299 config IP_NF_MATCH_OWNER
 300         tristate "Owner match support"
 301         depends on IP_NF_IPTABLES
 302         help
 303           Packet owner matching allows you to match locally-generated packets
 304           based on who created them: the user, group, process or session.
 305
 306           To compile it as a module, choose M here.  If unsure, say N.
 307
 308 config IP_NF_MATCH_ADDRTYPE
 309         tristate  'address type match support'
 310         depends on IP_NF_IPTABLES
 311         help
 312           This option allows you to match what routing thinks of an address,
 313           eg. UNICAST, LOCAL, BROADCAST, ...
 314
 315           If you want to compile it as a module, say M here and read
 316           <file:Documentation/modules.txt>.  If unsure, say `N'.
 317
 318 config IP_NF_MATCH_HASHLIMIT
 319         tristate  'hashlimit match support'
 320         depends on IP_NF_IPTABLES
 321         help
 322           This option adds a new iptables `hashlimit' match.
 323
 324           As opposed to `limit', this match dynamically creates a hash table
 325           of limit buckets, based on your selection of source/destination
 326           ip addresses and/or ports.
 327
 328           It enables you to express policies like `10kpps for any given
 329           destination IP' or `500pps from any given source IP'  with a single
 330           IPtables rule.
 331
 332 # `filter', generic and specific targets
 333 config IP_NF_FILTER
 334         tristate "Packet filtering"
 335         depends on IP_NF_IPTABLES
 336         help
 337           Packet filtering defines a table `filter', which has a series of
 338           rules for simple packet filtering at local input, forwarding and
 339           local output.  See the man page for iptables(8).
 340
 341           To compile it as a module, choose M here.  If unsure, say N.
 342
 343 config IP_NF_TARGET_REJECT
 344         tristate "REJECT target support"
 345         depends on IP_NF_FILTER
 346         help
 347           The REJECT target allows a filtering rule to specify that an ICMP
 348           error should be issued in response to an incoming packet, rather
 349           than silently being dropped.
 350
 351           To compile it as a module, choose M here.  If unsure, say N.
 352
 353 config IP_NF_TARGET_LOG
 354         tristate "LOG target support"
 355         depends on IP_NF_IPTABLES
 356         help
 357           This option adds a `LOG' target, which allows you to create rules in
 358           any iptables table which records the packet header to the syslog.
 359
 360           To compile it as a module, choose M here.  If unsure, say N.
 361
 362 config IP_NF_TARGET_ULOG
 363         tristate "ULOG target support"
 364         depends on IP_NF_IPTABLES
 365         ---help---
 366
 367           This option enables the old IPv4-only "ipt_ULOG" implementation
 368           which has been obsoleted by the new "nfnetlink_log" code (see
 369           CONFIG_NETFILTER_NETLINK_LOG).
 370
 371           This option adds a `ULOG' target, which allows you to create rules in
 372           any iptables table. The packet is passed to a userspace logging
 373           daemon using netlink multicast sockets; unlike the LOG target
 374           which can only be viewed through syslog.
 375
 376           The appropriate userspace logging daemon (ulogd) may be obtained from
 377           <http://www.gnumonks.org/projects/ulogd/>
 378
 379           To compile it as a module, choose M here.  If unsure, say N.
 380
 381 config IP_NF_TARGET_TCPMSS
 382         tristate "TCPMSS target support"
 383         depends on IP_NF_IPTABLES
 384         ---help---
 385           This option adds a `TCPMSS' target, which allows you to alter the
 386           MSS value of TCP SYN packets, to control the maximum size for that
 387           connection (usually limiting it to your outgoing interface's MTU
 388           minus 40).
 389
 390           This is used to overcome criminally braindead ISPs or servers which
 391           block ICMP Fragmentation Needed packets.  The symptoms of this
 392           problem are that everything works fine from your Linux
 393           firewall/router, but machines behind it can never exchange large
 394           packets:
 395                 1) Web browsers connect, then hang with no data received.
 396                 2) Small mail works fine, but large emails hang.
 397                 3) ssh works fine, but scp hangs after initial handshaking.
 398
 399           Workaround: activate this option and add a rule to your firewall
 400           configuration like:
 401
 402           iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN \
 403                          -j TCPMSS --clamp-mss-to-pmtu
 404
 405           To compile it as a module, choose M here.  If unsure, say N.
 406
 407 # NAT + specific targets
 408 config IP_NF_NAT
 409         tristate "Full NAT"
 410         depends on IP_NF_IPTABLES && IP_NF_CONNTRACK
 411         help
 412           The Full NAT option allows masquerading, port forwarding and other
 413           forms of full Network Address Port Translation.  It is controlled by
 414           the `nat' table in iptables: see the man page for iptables(8).
 415
 416           To compile it as a module, choose M here.  If unsure, say N.
 417
 418 config IP_NF_NAT_NEEDED
 419         bool
 420         depends on IP_NF_NAT != n
 421         default y
 422
 423 config IP_NF_TARGET_MASQUERADE
 424         tristate "MASQUERADE target support"
 425         depends on IP_NF_NAT
 426         help
 427           Masquerading is a special case of NAT: all outgoing connections are
 428           changed to seem to come from a particular interface's address, and
 429           if the interface goes down, those connections are lost.  This is
 430           only useful for dialup accounts with dynamic IP address (ie. your IP
 431           address will be different on next dialup).
 432
 433           To compile it as a module, choose M here.  If unsure, say N.
 434
 435 config IP_NF_TARGET_REDIRECT
 436         tristate "REDIRECT target support"
 437         depends on IP_NF_NAT
 438         help
 439           REDIRECT is a special case of NAT: all incoming connections are
 440           mapped onto the incoming interface's address, causing the packets to
 441           come to the local machine instead of passing through.  This is
 442           useful for transparent proxies.
 443
 444           To compile it as a module, choose M here.  If unsure, say N.
 445
 446 config IP_NF_TARGET_NETMAP
 447         tristate "NETMAP target support"
 448         depends on IP_NF_NAT
 449         help
 450           NETMAP is an implementation of static 1:1 NAT mapping of network
 451           addresses. It maps the network address part, while keeping the host
 452           address part intact. It is similar to Fast NAT, except that
 453           Netfilter's connection tracking doesn't work well with Fast NAT.
 454
 455           To compile it as a module, choose M here.  If unsure, say N.
 456
 457 config IP_NF_TARGET_SAME
 458         tristate "SAME target support"
 459         depends on IP_NF_NAT
 460         help
 461           This option adds a `SAME' target, which works like the standard SNAT
 462           target, but attempts to give clients the same IP for all connections.
 463
 464           To compile it as a module, choose M here.  If unsure, say N.
 465
 466 config IP_NF_NAT_SNMP_BASIC
 467         tristate "Basic SNMP-ALG support (EXPERIMENTAL)"
 468         depends on EXPERIMENTAL && IP_NF_NAT
 469         ---help---
 470
 471           This module implements an Application Layer Gateway (ALG) for
 472           SNMP payloads.  In conjunction with NAT, it allows a network
 473           management system to access multiple private networks with
 474           conflicting addresses.  It works by modifying IP addresses
 475           inside SNMP payloads to match IP-layer NAT mapping.
 476
 477           This is the "basic" form of SNMP-ALG, as described in RFC 2962
 478
 479           To compile it as a module, choose M here.  If unsure, say N.
 480
 481 config IP_NF_NAT_IRC
 482         tristate
 483         depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
 484         default IP_NF_NAT if IP_NF_IRC=y
 485         default m if IP_NF_IRC=m
 486
 487 # If they want FTP, set to $CONFIG_IP_NF_NAT (m or y),
 488 # or $CONFIG_IP_NF_FTP (m or y), whichever is weaker.  Argh.
 489 config IP_NF_NAT_FTP
 490         tristate
 491         depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
 492         default IP_NF_NAT if IP_NF_FTP=y
 493         default m if IP_NF_FTP=m
 494
 495 config IP_NF_NAT_TFTP
 496         tristate
 497         depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
 498         default IP_NF_NAT if IP_NF_TFTP=y
 499         default m if IP_NF_TFTP=m
 500
 501 config IP_NF_NAT_AMANDA
 502         tristate
 503         depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
 504         default IP_NF_NAT if IP_NF_AMANDA=y
 505         default m if IP_NF_AMANDA=m
 506
 507 config IP_NF_NAT_PPTP
 508         tristate
 509         depends on IP_NF_NAT!=n && IP_NF_PPTP!=n
 510         default IP_NF_NAT if IP_NF_PPTP=y
 511         default m if IP_NF_PPTP=m
 512
 513 config IP_NF_NAT_H323
 514         tristate
 515         depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
 516         default IP_NF_NAT if IP_NF_H323=y
 517         default m if IP_NF_H323=m
 518
 519 config IP_NF_NAT_SIP
 520         tristate
 521         depends on IP_NF_IPTABLES!=n && IP_NF_CONNTRACK!=n && IP_NF_NAT!=n
 522         default IP_NF_NAT if IP_NF_SIP=y
 523         default m if IP_NF_SIP=m
 524
 525 # mangle + specific targets
 526 config IP_NF_MANGLE
 527         tristate "Packet mangling"
 528         depends on IP_NF_IPTABLES
 529         help
 530           This option adds a `mangle' table to iptables: see the man page for
 531           iptables(8).  This table is used for various packet alterations
 532           which can effect how the packet is routed.
 533
 534           To compile it as a module, choose M here.  If unsure, say N.
 535
 536 config IP_NF_TARGET_TOS
 537         tristate "TOS target support"
 538         depends on IP_NF_MANGLE
 539         help
 540           This option adds a `TOS' target, which allows you to create rules in
 541           the `mangle' table which alter the Type Of Service field of an IP
 542           packet prior to routing.
 543
 544           To compile it as a module, choose M here.  If unsure, say N.
 545
 546 config IP_NF_TARGET_ECN
 547         tristate "ECN target support"
 548         depends on IP_NF_MANGLE
 549         ---help---
 550           This option adds a `ECN' target, which can be used in the iptables mangle
 551           table.
 552
 553           You can use this target to remove the ECN bits from the IPv4 header of
 554           an IP packet.  This is particularly useful, if you need to work around
 555           existing ECN blackholes on the internet, but don't want to disable
 556           ECN support in general.
 557
 558           To compile it as a module, choose M here.  If unsure, say N.
 559
 560 config IP_NF_TARGET_TTL
 561         tristate  'TTL target support'
 562         depends on IP_NF_MANGLE
 563         help
 564           This option adds a `TTL' target, which enables the user to modify
 565           the TTL value of the IP header.
 566
 567           While it is safe to decrement/lower the TTL, this target also enables
 568           functionality to increment and set the TTL value of the IP header to
 569           arbitrary values.  This is EXTREMELY DANGEROUS since you can easily
 570           create immortal packets that loop forever on the network.
 571
 572           To compile it as a module, choose M here.  If unsure, say N.
 573
 574 config IP_NF_TARGET_CLUSTERIP
 575         tristate "CLUSTERIP target support (EXPERIMENTAL)"
 576         depends on IP_NF_MANGLE && EXPERIMENTAL
 577         depends on (IP_NF_CONNTRACK && IP_NF_CONNTRACK_MARK) || (NF_CONNTRACK_MARK && NF_CONNTRACK_IPV4)
 578         help
 579           The CLUSTERIP target allows you to build load-balancing clusters of
 580           network servers without having a dedicated load-balancing
 581           router/server/switch.
 582
 583           To compile it as a module, choose M here.  If unsure, say N.
 584
 585 # raw + specific targets
 586 config IP_NF_RAW
 587         tristate  'raw table support (required for NOTRACK/TRACE)'
 588         depends on IP_NF_IPTABLES
 589         help
 590           This option adds a `raw' table to iptables. This table is the very
 591           first in the netfilter framework and hooks in at the PREROUTING
 592           and OUTPUT chains.
 593
 594           If you want to compile it as a module, say M here and read
 595           <file:Documentation/modules.txt>.  If unsure, say `N'.
 596
 597 # ARP tables
 598 config IP_NF_ARPTABLES
 599         tristate "ARP tables support"
 600         depends on NETFILTER_XTABLES
 601         help
 602           arptables is a general, extensible packet identification framework.
 603           The ARP packet filtering and mangling (manipulation)subsystems
 604           use this: say Y or M here if you want to use either of those.
 605
 606           To compile it as a module, choose M here.  If unsure, say N.
 607
 608 config IP_NF_ARPFILTER
 609         tristate "ARP packet filtering"
 610         depends on IP_NF_ARPTABLES
 611         help
 612           ARP packet filtering defines a table `filter', which has a series of
 613           rules for simple ARP packet filtering at local input and
 614           local output.  On a bridge, you can also specify filtering rules
 615           for forwarded ARP packets. See the man page for arptables(8).
 616
 617           To compile it as a module, choose M here.  If unsure, say N.
 618
 619 config IP_NF_ARP_MANGLE
 620         tristate "ARP payload mangling"
 621         depends on IP_NF_ARPTABLES
 622         help
 623           Allows altering the ARP packet payload: source and destination
 624           hardware and network addresses.
 625
 626 endmenu
 627