net/netfilter/Kconfig

   1 menu "Core Netfilter Configuration"
   2         depends on NET && INET && NETFILTER
   3
   4 config NETFILTER_NETLINK
   5         tristate
   6
   7 config NETFILTER_NETLINK_QUEUE
   8         tristate "Netfilter NFQUEUE over NFNETLINK interface"
   9         depends on NETFILTER_ADVANCED
  10         select NETFILTER_NETLINK
  11         help
  12           If this option is enabled, the kernel will include support
  13           for queueing packets via NFNETLINK.
  14
  15 config NETFILTER_NETLINK_LOG
  16         tristate "Netfilter LOG over NFNETLINK interface"
  17         default m if NETFILTER_ADVANCED=n
  18         select NETFILTER_NETLINK
  19         help
  20           If this option is enabled, the kernel will include support
  21           for logging packets via NFNETLINK.
  22
  23           This obsoletes the existing ipt_ULOG and ebg_ulog mechanisms,
  24           and is also scheduled to replace the old syslog-based ipt_LOG
  25           and ip6t_LOG modules.
  26
  27 config NF_CONNTRACK
  28         tristate "Netfilter connection tracking support"
  29         default m if NETFILTER_ADVANCED=n
  30         help
  31           Connection tracking keeps a record of what packets have passed
  32           through your machine, in order to figure out how they are related
  33           into connections.
  34
  35           This is required to do Masquerading or other kinds of Network
  36           Address Translation (except for Fast NAT).  It can also be used to
  37           enhance packet filtering (see `Connection state match support'
  38           below).
  39
  40           To compile it as a module, choose M here.  If unsure, say N.
  41
  42 config NF_CT_ACCT
  43         bool "Connection tracking flow accounting"
  44         depends on NETFILTER_ADVANCED
  45         depends on NF_CONNTRACK
  46         help
  47           If this option is enabled, the connection tracking code will
  48           keep per-flow packet and byte counters.
  49
  50           Those counters can be used for flow-based accounting or the
  51           `connbytes' match.
  52
  53           If unsure, say `N'.
  54
  55 config NF_CONNTRACK_MARK
  56         bool  'Connection mark tracking support'
  57         depends on NETFILTER_ADVANCED
  58         depends on NF_CONNTRACK
  59         help
  60           This option enables support for connection marks, used by the
  61           `CONNMARK' target and `connmark' match. Similar to the mark value
  62           of packets, but this mark value is kept in the conntrack session
  63           instead of the individual packets.
  64
  65 config NF_CONNTRACK_SECMARK
  66         bool  'Connection tracking security mark support'
  67         depends on NF_CONNTRACK && NETWORK_SECMARK
  68         default m if NETFILTER_ADVANCED=n
  69         help
  70           This option enables security markings to be applied to
  71           connections.  Typically they are copied to connections from
  72           packets using the CONNSECMARK target and copied back from
  73           connections to packets with the same target, with the packets
  74           being originally labeled via SECMARK.
  75
  76           If unsure, say 'N'.
  77
  78 config NF_CONNTRACK_EVENTS
  79         bool "Connection tracking events (EXPERIMENTAL)"
  80         depends on EXPERIMENTAL && NF_CONNTRACK
  81         depends on NETFILTER_ADVANCED
  82         help
  83           If this option is enabled, the connection tracking code will
  84           provide a notifier chain that can be used by other kernel code
  85           to get notified about changes in the connection tracking state.
  86
  87           If unsure, say `N'.
  88
  89 config NF_CT_PROTO_GRE
  90         tristate
  91         depends on NF_CONNTRACK
  92
  93 config NF_CT_PROTO_SCTP
  94         tristate 'SCTP protocol connection tracking support (EXPERIMENTAL)'
  95         depends on EXPERIMENTAL && NF_CONNTRACK
  96         depends on NETFILTER_ADVANCED
  97         help
  98           With this option enabled, the layer 3 independent connection
  99           tracking code will be able to do state tracking on SCTP connections.
 100
 101           If you want to compile it as a module, say M here and read
 102           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 103
 104 config NF_CT_PROTO_UDPLITE
 105         tristate 'UDP-Lite protocol connection tracking support (EXPERIMENTAL)'
 106         depends on EXPERIMENTAL && NF_CONNTRACK
 107         depends on NETFILTER_ADVANCED
 108         help
 109           With this option enabled, the layer 3 independent connection
 110           tracking code will be able to do state tracking on UDP-Lite
 111           connections.
 112
 113           To compile it as a module, choose M here.  If unsure, say N.
 114
 115 config NF_CONNTRACK_AMANDA
 116         tristate "Amanda backup protocol support"
 117         depends on NF_CONNTRACK
 118         depends on NETFILTER_ADVANCED
 119         select TEXTSEARCH
 120         select TEXTSEARCH_KMP
 121         help
 122           If you are running the Amanda backup package <http://www.amanda.org/>
 123           on this machine or machines that will be MASQUERADED through this
 124           machine, then you may want to enable this feature.  This allows the
 125           connection tracking and natting code to allow the sub-channels that
 126           Amanda requires for communication of the backup data, messages and
 127           index.
 128
 129           To compile it as a module, choose M here.  If unsure, say N.
 130
 131 config NF_CONNTRACK_FTP
 132         tristate "FTP protocol support"
 133         depends on NF_CONNTRACK
 134         default m if NETFILTER_ADVANCED=n
 135         help
 136           Tracking FTP connections is problematic: special helpers are
 137           required for tracking them, and doing masquerading and other forms
 138           of Network Address Translation on them.
 139
 140           This is FTP support on Layer 3 independent connection tracking.
 141           Layer 3 independent connection tracking is experimental scheme
 142           which generalize ip_conntrack to support other layer 3 protocols.
 143
 144           To compile it as a module, choose M here.  If unsure, say N.
 145
 146 config NF_CONNTRACK_H323
 147         tristate "H.323 protocol support (EXPERIMENTAL)"
 148         depends on EXPERIMENTAL && NF_CONNTRACK && (IPV6 || IPV6=n)
 149         depends on NETFILTER_ADVANCED
 150         help
 151           H.323 is a VoIP signalling protocol from ITU-T. As one of the most
 152           important VoIP protocols, it is widely used by voice hardware and
 153           software including voice gateways, IP phones, Netmeeting, OpenPhone,
 154           Gnomemeeting, etc.
 155
 156           With this module you can support H.323 on a connection tracking/NAT
 157           firewall.
 158
 159           This module supports RAS, Fast Start, H.245 Tunnelling, Call
 160           Forwarding, RTP/RTCP and T.120 based audio, video, fax, chat,
 161           whiteboard, file transfer, etc. For more information, please
 162           visit http://nath323.sourceforge.net/.
 163
 164           To compile it as a module, choose M here.  If unsure, say N.
 165
 166 config NF_CONNTRACK_IRC
 167         tristate "IRC protocol support"
 168         depends on NF_CONNTRACK
 169         default m if NETFILTER_ADVANCED=n
 170         help
 171           There is a commonly-used extension to IRC called
 172           Direct Client-to-Client Protocol (DCC).  This enables users to send
 173           files to each other, and also chat to each other without the need
 174           of a server.  DCC Sending is used anywhere you send files over IRC,
 175           and DCC Chat is most commonly used by Eggdrop bots.  If you are
 176           using NAT, this extension will enable you to send files and initiate
 177           chats.  Note that you do NOT need this extension to get files or
 178           have others initiate chats, or everything else in IRC.
 179
 180           To compile it as a module, choose M here.  If unsure, say N.
 181
 182 config NF_CONNTRACK_NETBIOS_NS
 183         tristate "NetBIOS name service protocol support (EXPERIMENTAL)"
 184         depends on EXPERIMENTAL && NF_CONNTRACK
 185         depends on NETFILTER_ADVANCED
 186         help
 187           NetBIOS name service requests are sent as broadcast messages from an
 188           unprivileged port and responded to with unicast messages to the
 189           same port. This make them hard to firewall properly because connection
 190           tracking doesn't deal with broadcasts. This helper tracks locally
 191           originating NetBIOS name service requests and the corresponding
 192           responses. It relies on correct IP address configuration, specifically
 193           netmask and broadcast address. When properly configured, the output
 194           of "ip address show" should look similar to this:
 195
 196           $ ip -4 address show eth0
 197           4: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
 198               inet 172.16.2.252/24 brd 172.16.2.255 scope global eth0
 199
 200           To compile it as a module, choose M here.  If unsure, say N.
 201
 202 config NF_CONNTRACK_PPTP
 203         tristate "PPtP protocol support"
 204         depends on NF_CONNTRACK
 205         depends on NETFILTER_ADVANCED
 206         select NF_CT_PROTO_GRE
 207         help
 208           This module adds support for PPTP (Point to Point Tunnelling
 209           Protocol, RFC2637) connection tracking and NAT.
 210
 211           If you are running PPTP sessions over a stateful firewall or NAT
 212           box, you may want to enable this feature.
 213
 214           Please note that not all PPTP modes of operation are supported yet.
 215           Specifically these limitations exist:
 216             - Blindly assumes that control connections are always established
 217               in PNS->PAC direction. This is a violation of RFC2637.
 218             - Only supports a single call within each session
 219
 220           To compile it as a module, choose M here.  If unsure, say N.
 221
 222 config NF_CONNTRACK_SANE
 223         tristate "SANE protocol support (EXPERIMENTAL)"
 224         depends on EXPERIMENTAL && NF_CONNTRACK
 225         depends on NETFILTER_ADVANCED
 226         help
 227           SANE is a protocol for remote access to scanners as implemented
 228           by the 'saned' daemon. Like FTP, it uses separate control and
 229           data connections.
 230
 231           With this module you can support SANE on a connection tracking
 232           firewall.
 233
 234           To compile it as a module, choose M here.  If unsure, say N.
 235
 236 config NF_CONNTRACK_SIP
 237         tristate "SIP protocol support (EXPERIMENTAL)"
 238         depends on EXPERIMENTAL && NF_CONNTRACK
 239         default m if NETFILTER_ADVANCED=n
 240         help
 241           SIP is an application-layer control protocol that can establish,
 242           modify, and terminate multimedia sessions (conferences) such as
 243           Internet telephony calls. With the ip_conntrack_sip and
 244           the nf_nat_sip modules you can support the protocol on a connection
 245           tracking/NATing firewall.
 246
 247           To compile it as a module, choose M here.  If unsure, say N.
 248
 249 config NF_CONNTRACK_TFTP
 250         tristate "TFTP protocol support"
 251         depends on NF_CONNTRACK
 252         depends on NETFILTER_ADVANCED
 253         help
 254           TFTP connection tracking helper, this is required depending
 255           on how restrictive your ruleset is.
 256           If you are using a tftp client behind -j SNAT or -j MASQUERADING
 257           you will need this.
 258
 259           To compile it as a module, choose M here.  If unsure, say N.
 260
 261 config NF_CT_NETLINK
 262         tristate 'Connection tracking netlink interface (EXPERIMENTAL)'
 263         depends on EXPERIMENTAL && NF_CONNTRACK
 264         select NETFILTER_NETLINK
 265         depends on NF_NAT=n || NF_NAT
 266         default m if NETFILTER_ADVANCED=n
 267         help
 268           This option enables support for a netlink-based userspace interface
 269
 270 config NETFILTER_XTABLES
 271         tristate "Netfilter Xtables support (required for ip_tables)"
 272         default m if NETFILTER_ADVANCED=n
 273         help
 274           This is required if you intend to use any of ip_tables,
 275           ip6_tables or arp_tables.
 276
 277 # alphabetically ordered list of targets
 278
 279 config NETFILTER_XT_TARGET_CLASSIFY
 280         tristate '"CLASSIFY" target support'
 281         depends on NETFILTER_XTABLES
 282         depends on NETFILTER_ADVANCED
 283         help
 284           This option adds a `CLASSIFY' target, which enables the user to set
 285           the priority of a packet. Some qdiscs can use this value for
 286           classification, among these are:
 287
 288           atm, cbq, dsmark, pfifo_fast, htb, prio
 289
 290           To compile it as a module, choose M here.  If unsure, say N.
 291
 292 config NETFILTER_XT_TARGET_CONNMARK
 293         tristate  '"CONNMARK" target support'
 294         depends on NETFILTER_XTABLES
 295         depends on IP_NF_MANGLE || IP6_NF_MANGLE
 296         depends on NF_CONNTRACK
 297         depends on NETFILTER_ADVANCED
 298         select NF_CONNTRACK_MARK
 299         help
 300           This option adds a `CONNMARK' target, which allows one to manipulate
 301           the connection mark value.  Similar to the MARK target, but
 302           affects the connection mark value rather than the packet mark value.
 303
 304           If you want to compile it as a module, say M here and read
 305           <file:Documentation/kbuild/modules.txt>.  The module will be called
 306           ipt_CONNMARK.ko.  If unsure, say `N'.
 307
 308 config NETFILTER_XT_TARGET_DSCP
 309         tristate '"DSCP" and "TOS" target support'
 310         depends on NETFILTER_XTABLES
 311         depends on IP_NF_MANGLE || IP6_NF_MANGLE
 312         depends on NETFILTER_ADVANCED
 313         help
 314           This option adds a `DSCP' target, which allows you to manipulate
 315           the IPv4/IPv6 header DSCP field (differentiated services codepoint).
 316
 317           The DSCP field can have any value between 0x0 and 0x3f inclusive.
 318
 319           It also adds the "TOS" target, which allows you to create rules in
 320           the "mangle" table which alter the Type Of Service field of an IPv4
 321           or the Priority field of an IPv6 packet, prior to routing.
 322
 323           To compile it as a module, choose M here.  If unsure, say N.
 324
 325 config NETFILTER_XT_TARGET_MARK
 326         tristate '"MARK" target support'
 327         depends on NETFILTER_XTABLES
 328         default m if NETFILTER_ADVANCED=n
 329         help
 330           This option adds a `MARK' target, which allows you to create rules
 331           in the `mangle' table which alter the netfilter mark (nfmark) field
 332           associated with the packet prior to routing. This can change
 333           the routing method (see `Use netfilter MARK value as routing
 334           key') and can also be used by other subsystems to change their
 335           behavior.
 336
 337           To compile it as a module, choose M here.  If unsure, say N.
 338
 339 config NETFILTER_XT_TARGET_NFQUEUE
 340         tristate '"NFQUEUE" target Support'
 341         depends on NETFILTER_XTABLES
 342         depends on NETFILTER_ADVANCED
 343         help
 344           This target replaced the old obsolete QUEUE target.
 345
 346           As opposed to QUEUE, it supports 65535 different queues,
 347           not just one.
 348
 349           To compile it as a module, choose M here.  If unsure, say N.
 350
 351 config NETFILTER_XT_TARGET_NFLOG
 352         tristate '"NFLOG" target support'
 353         depends on NETFILTER_XTABLES
 354         default m if NETFILTER_ADVANCED=n
 355         help
 356           This option enables the NFLOG target, which allows to LOG
 357           messages through the netfilter logging API, which can use
 358           either the old LOG target, the old ULOG target or nfnetlink_log
 359           as backend.
 360
 361           To compile it as a module, choose M here.  If unsure, say N.
 362
 363 config NETFILTER_XT_TARGET_NOTRACK
 364         tristate  '"NOTRACK" target support'
 365         depends on NETFILTER_XTABLES
 366         depends on IP_NF_RAW || IP6_NF_RAW
 367         depends on NF_CONNTRACK
 368         depends on NETFILTER_ADVANCED
 369         help
 370           The NOTRACK target allows a select rule to specify
 371           which packets *not* to enter the conntrack/NAT
 372           subsystem with all the consequences (no ICMP error tracking,
 373           no protocol helpers for the selected packets).
 374
 375           If you want to compile it as a module, say M here and read
 376           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 377
 378 config NETFILTER_XT_TARGET_RATEEST
 379         tristate '"RATEEST" target support'
 380         depends on NETFILTER_XTABLES
 381         depends on NETFILTER_ADVANCED
 382         help
 383           This option adds a `RATEEST' target, which allows to measure
 384           rates similar to TC estimators. The `rateest' match can be
 385           used to match on the measured rates.
 386
 387           To compile it as a module, choose M here.  If unsure, say N.
 388
 389 config NETFILTER_XT_TARGET_TRACE
 390         tristate  '"TRACE" target support'
 391         depends on NETFILTER_XTABLES
 392         depends on IP_NF_RAW || IP6_NF_RAW
 393         depends on NETFILTER_ADVANCED
 394         help
 395           The TRACE target allows you to mark packets so that the kernel
 396           will log every rule which match the packets as those traverse
 397           the tables, chains, rules.
 398
 399           If you want to compile it as a module, say M here and read
 400           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 401
 402 config NETFILTER_XT_TARGET_SECMARK
 403         tristate '"SECMARK" target support'
 404         depends on NETFILTER_XTABLES && NETWORK_SECMARK
 405         default m if NETFILTER_ADVANCED=n
 406         help
 407           The SECMARK target allows security marking of network
 408           packets, for use with security subsystems.
 409
 410           To compile it as a module, choose M here.  If unsure, say N.
 411
 412 config NETFILTER_XT_TARGET_CONNSECMARK
 413         tristate '"CONNSECMARK" target support'
 414         depends on NETFILTER_XTABLES && NF_CONNTRACK && NF_CONNTRACK_SECMARK
 415         default m if NETFILTER_ADVANCED=n
 416         help
 417           The CONNSECMARK target copies security markings from packets
 418           to connections, and restores security markings from connections
 419           to packets (if the packets are not already marked).  This would
 420           normally be used in conjunction with the SECMARK target.
 421
 422           To compile it as a module, choose M here.  If unsure, say N.
 423
 424 config NETFILTER_XT_TARGET_TCPMSS
 425         tristate '"TCPMSS" target support'
 426         depends on NETFILTER_XTABLES && (IPV6 || IPV6=n)
 427         default m if NETFILTER_ADVANCED=n
 428         ---help---
 429           This option adds a `TCPMSS' target, which allows you to alter the
 430           MSS value of TCP SYN packets, to control the maximum size for that
 431           connection (usually limiting it to your outgoing interface's MTU
 432           minus 40).
 433
 434           This is used to overcome criminally braindead ISPs or servers which
 435           block ICMP Fragmentation Needed packets.  The symptoms of this
 436           problem are that everything works fine from your Linux
 437           firewall/router, but machines behind it can never exchange large
 438           packets:
 439                 1) Web browsers connect, then hang with no data received.
 440                 2) Small mail works fine, but large emails hang.
 441                 3) ssh works fine, but scp hangs after initial handshaking.
 442
 443           Workaround: activate this option and add a rule to your firewall
 444           configuration like:
 445
 446           iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN \
 447                          -j TCPMSS --clamp-mss-to-pmtu
 448
 449           To compile it as a module, choose M here.  If unsure, say N.
 450
 451 config NETFILTER_XT_TARGET_TCPOPTSTRIP
 452         tristate '"TCPOPTSTRIP" target support (EXPERIMENTAL)'
 453         depends on EXPERIMENTAL && NETFILTER_XTABLES
 454         depends on IP_NF_MANGLE || IP6_NF_MANGLE
 455         depends on NETFILTER_ADVANCED
 456         help
 457           This option adds a "TCPOPTSTRIP" target, which allows you to strip
 458           TCP options from TCP packets.
 459
 460 config NETFILTER_XT_MATCH_COMMENT
 461         tristate  '"comment" match support'
 462         depends on NETFILTER_XTABLES
 463         depends on NETFILTER_ADVANCED
 464         help
 465           This option adds a `comment' dummy-match, which allows you to put
 466           comments in your iptables ruleset.
 467
 468           If you want to compile it as a module, say M here and read
 469           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 470
 471 config NETFILTER_XT_MATCH_CONNBYTES
 472         tristate  '"connbytes" per-connection counter match support'
 473         depends on NETFILTER_XTABLES
 474         depends on NF_CONNTRACK
 475         depends on NETFILTER_ADVANCED
 476         select NF_CT_ACCT
 477         help
 478           This option adds a `connbytes' match, which allows you to match the
 479           number of bytes and/or packets for each direction within a connection.
 480
 481           If you want to compile it as a module, say M here and read
 482           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 483
 484 config NETFILTER_XT_MATCH_CONNLIMIT
 485         tristate '"connlimit" match support"'
 486         depends on NETFILTER_XTABLES
 487         depends on NF_CONNTRACK
 488         depends on NETFILTER_ADVANCED
 489         ---help---
 490           This match allows you to match against the number of parallel
 491           connections to a server per client IP address (or address block).
 492
 493 config NETFILTER_XT_MATCH_CONNMARK
 494         tristate  '"connmark" connection mark match support'
 495         depends on NETFILTER_XTABLES
 496         depends on NF_CONNTRACK
 497         depends on NETFILTER_ADVANCED
 498         select NF_CONNTRACK_MARK
 499         help
 500           This option adds a `connmark' match, which allows you to match the
 501           connection mark value previously set for the session by `CONNMARK'.
 502
 503           If you want to compile it as a module, say M here and read
 504           <file:Documentation/kbuild/modules.txt>.  The module will be called
 505           ipt_connmark.ko.  If unsure, say `N'.
 506
 507 config NETFILTER_XT_MATCH_CONNTRACK
 508         tristate '"conntrack" connection tracking match support'
 509         depends on NETFILTER_XTABLES
 510         depends on NF_CONNTRACK
 511         default m if NETFILTER_ADVANCED=n
 512         help
 513           This is a general conntrack match module, a superset of the state match.
 514
 515           It allows matching on additional conntrack information, which is
 516           useful in complex configurations, such as NAT gateways with multiple
 517           internet links or tunnels.
 518
 519           To compile it as a module, choose M here.  If unsure, say N.
 520
 521 config NETFILTER_XT_MATCH_DCCP
 522         tristate '"dccp" protocol match support'
 523         depends on NETFILTER_XTABLES
 524         depends on NETFILTER_ADVANCED
 525         help
 526           With this option enabled, you will be able to use the iptables
 527           `dccp' match in order to match on DCCP source/destination ports
 528           and DCCP flags.
 529
 530           If you want to compile it as a module, say M here and read
 531           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 532
 533 config NETFILTER_XT_MATCH_DSCP
 534         tristate '"dscp" and "tos" match support'
 535         depends on NETFILTER_XTABLES
 536         depends on NETFILTER_ADVANCED
 537         help
 538           This option adds a `DSCP' match, which allows you to match against
 539           the IPv4/IPv6 header DSCP field (differentiated services codepoint).
 540
 541           The DSCP field can have any value between 0x0 and 0x3f inclusive.
 542
 543           It will also add a "tos" match, which allows you to match packets
 544           based on the Type Of Service fields of the IPv4 packet (which share
 545           the same bits as DSCP).
 546
 547           To compile it as a module, choose M here.  If unsure, say N.
 548
 549 config NETFILTER_XT_MATCH_ESP
 550         tristate '"esp" match support'
 551         depends on NETFILTER_XTABLES
 552         depends on NETFILTER_ADVANCED
 553         help
 554           This match extension allows you to match a range of SPIs
 555           inside ESP header of IPSec packets.
 556
 557           To compile it as a module, choose M here.  If unsure, say N.
 558
 559 config NETFILTER_XT_MATCH_HELPER
 560         tristate '"helper" match support'
 561         depends on NETFILTER_XTABLES
 562         depends on NF_CONNTRACK
 563         depends on NETFILTER_ADVANCED
 564         help
 565           Helper matching allows you to match packets in dynamic connections
 566           tracked by a conntrack-helper, ie. ip_conntrack_ftp
 567
 568           To compile it as a module, choose M here.  If unsure, say Y.
 569
 570 config NETFILTER_XT_MATCH_LENGTH
 571         tristate '"length" match support'
 572         depends on NETFILTER_XTABLES
 573         depends on NETFILTER_ADVANCED
 574         help
 575           This option allows you to match the length of a packet against a
 576           specific value or range of values.
 577
 578           To compile it as a module, choose M here.  If unsure, say N.
 579
 580 config NETFILTER_XT_MATCH_LIMIT
 581         tristate '"limit" match support'
 582         depends on NETFILTER_XTABLES
 583         depends on NETFILTER_ADVANCED
 584         help
 585           limit matching allows you to control the rate at which a rule can be
 586           matched: mainly useful in combination with the LOG target ("LOG
 587           target support", below) and to avoid some Denial of Service attacks.
 588
 589           To compile it as a module, choose M here.  If unsure, say N.
 590
 591 config NETFILTER_XT_MATCH_MAC
 592         tristate '"mac" address match support'
 593         depends on NETFILTER_XTABLES
 594         depends on NETFILTER_ADVANCED
 595         help
 596           MAC matching allows you to match packets based on the source
 597           Ethernet address of the packet.
 598
 599           To compile it as a module, choose M here.  If unsure, say N.
 600
 601 config NETFILTER_XT_MATCH_MARK
 602         tristate '"mark" match support'
 603         depends on NETFILTER_XTABLES
 604         default m if NETFILTER_ADVANCED=n
 605         help
 606           Netfilter mark matching allows you to match packets based on the
 607           `nfmark' value in the packet.  This can be set by the MARK target
 608           (see below).
 609
 610           To compile it as a module, choose M here.  If unsure, say N.
 611
 612 config NETFILTER_XT_MATCH_OWNER
 613         tristate '"owner" match support'
 614         depends on NETFILTER_XTABLES
 615         depends on NETFILTER_ADVANCED
 616         ---help---
 617         Socket owner matching allows you to match locally-generated packets
 618         based on who created the socket: the user or group. It is also
 619         possible to check whether a socket actually exists.
 620
 621 config NETFILTER_XT_MATCH_POLICY
 622         tristate 'IPsec "policy" match support'
 623         depends on NETFILTER_XTABLES && XFRM
 624         default m if NETFILTER_ADVANCED=n
 625         help
 626           Policy matching allows you to match packets based on the
 627           IPsec policy that was used during decapsulation/will
 628           be used during encapsulation.
 629
 630           To compile it as a module, choose M here.  If unsure, say N.
 631
 632 config NETFILTER_XT_MATCH_MULTIPORT
 633         tristate '"multiport" Multiple port match support'
 634         depends on NETFILTER_XTABLES
 635         depends on NETFILTER_ADVANCED
 636         help
 637           Multiport matching allows you to match TCP or UDP packets based on
 638           a series of source or destination ports: normally a rule can only
 639           match a single range of ports.
 640
 641           To compile it as a module, choose M here.  If unsure, say N.
 642
 643 config NETFILTER_XT_MATCH_PHYSDEV
 644         tristate '"physdev" match support'
 645         depends on NETFILTER_XTABLES && BRIDGE && BRIDGE_NETFILTER
 646         depends on NETFILTER_ADVANCED
 647         help
 648           Physdev packet matching matches against the physical bridge ports
 649           the IP packet arrived on or will leave by.
 650
 651           To compile it as a module, choose M here.  If unsure, say N.
 652
 653 config NETFILTER_XT_MATCH_PKTTYPE
 654         tristate '"pkttype" packet type match support'
 655         depends on NETFILTER_XTABLES
 656         depends on NETFILTER_ADVANCED
 657         help
 658           Packet type matching allows you to match a packet by
 659           its "class", eg. BROADCAST, MULTICAST, ...
 660
 661           Typical usage:
 662           iptables -A INPUT -m pkttype --pkt-type broadcast -j LOG
 663
 664           To compile it as a module, choose M here.  If unsure, say N.
 665
 666 config NETFILTER_XT_MATCH_QUOTA
 667         tristate '"quota" match support'
 668         depends on NETFILTER_XTABLES
 669         depends on NETFILTER_ADVANCED
 670         help
 671           This option adds a `quota' match, which allows to match on a
 672           byte counter.
 673
 674           If you want to compile it as a module, say M here and read
 675           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 676
 677 config NETFILTER_XT_MATCH_RATEEST
 678         tristate '"rateest" match support'
 679         depends on NETFILTER_XTABLES
 680         depends on NETFILTER_ADVANCED
 681         select NETFILTER_XT_TARGET_RATEEST
 682         help
 683           This option adds a `rateest' match, which allows to match on the
 684           rate estimated by the RATEEST target.
 685
 686           To compile it as a module, choose M here.  If unsure, say N.
 687
 688 config NETFILTER_XT_MATCH_REALM
 689         tristate  '"realm" match support'
 690         depends on NETFILTER_XTABLES
 691         depends on NETFILTER_ADVANCED
 692         select NET_CLS_ROUTE
 693         help
 694           This option adds a `realm' match, which allows you to use the realm
 695           key from the routing subsystem inside iptables.
 696
 697           This match pretty much resembles the CONFIG_NET_CLS_ROUTE4 option
 698           in tc world.
 699
 700           If you want to compile it as a module, say M here and read
 701           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 702
 703 config NETFILTER_XT_MATCH_SCTP
 704         tristate  '"sctp" protocol match support (EXPERIMENTAL)'
 705         depends on NETFILTER_XTABLES && EXPERIMENTAL
 706         depends on NETFILTER_ADVANCED
 707         help
 708           With this option enabled, you will be able to use the
 709           `sctp' match in order to match on SCTP source/destination ports
 710           and SCTP chunk types.
 711
 712           If you want to compile it as a module, say M here and read
 713           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 714
 715 config NETFILTER_XT_MATCH_STATE
 716         tristate '"state" match support'
 717         depends on NETFILTER_XTABLES
 718         depends on NF_CONNTRACK
 719         default m if NETFILTER_ADVANCED=n
 720         help
 721           Connection state matching allows you to match packets based on their
 722           relationship to a tracked connection (ie. previous packets).  This
 723           is a powerful tool for packet classification.
 724
 725           To compile it as a module, choose M here.  If unsure, say N.
 726
 727 config NETFILTER_XT_MATCH_STATISTIC
 728         tristate '"statistic" match support'
 729         depends on NETFILTER_XTABLES
 730         depends on NETFILTER_ADVANCED
 731         help
 732           This option adds a `statistic' match, which allows you to match
 733           on packets periodically or randomly with a given percentage.
 734
 735           To compile it as a module, choose M here.  If unsure, say N.
 736
 737 config NETFILTER_XT_MATCH_STRING
 738         tristate  '"string" match support'
 739         depends on NETFILTER_XTABLES
 740         depends on NETFILTER_ADVANCED
 741         select TEXTSEARCH
 742         select TEXTSEARCH_KMP
 743         select TEXTSEARCH_BM
 744         select TEXTSEARCH_FSM
 745         help
 746           This option adds a `string' match, which allows you to look for
 747           pattern matchings in packets.
 748
 749           To compile it as a module, choose M here.  If unsure, say N.
 750
 751 config NETFILTER_XT_MATCH_TCPMSS
 752         tristate '"tcpmss" match support'
 753         depends on NETFILTER_XTABLES
 754         depends on NETFILTER_ADVANCED
 755         help
 756           This option adds a `tcpmss' match, which allows you to examine the
 757           MSS value of TCP SYN packets, which control the maximum packet size
 758           for that connection.
 759
 760           To compile it as a module, choose M here.  If unsure, say N.
 761
 762 config NETFILTER_XT_MATCH_TIME
 763         tristate '"time" match support'
 764         depends on NETFILTER_XTABLES
 765         depends on NETFILTER_ADVANCED
 766         ---help---
 767           This option adds a "time" match, which allows you to match based on
 768           the packet arrival time (at the machine which netfilter is running)
 769           on) or departure time/date (for locally generated packets).
 770
 771           If you say Y here, try `iptables -m time --help` for
 772           more information.
 773
 774           If you want to compile it as a module, say M here.
 775           If unsure, say N.
 776
 777 config NETFILTER_XT_MATCH_U32
 778         tristate '"u32" match support'
 779         depends on NETFILTER_XTABLES
 780         depends on NETFILTER_ADVANCED
 781         ---help---
 782           u32 allows you to extract quantities of up to 4 bytes from a packet,
 783           AND them with specified masks, shift them by specified amounts and
 784           test whether the results are in any of a set of specified ranges.
 785           The specification of what to extract is general enough to skip over
 786           headers with lengths stored in the packet, as in IP or TCP header
 787           lengths.
 788
 789           Details and examples are in the kernel module source.
 790
 791 config NETFILTER_XT_MATCH_HASHLIMIT
 792         tristate '"hashlimit" match support'
 793         depends on NETFILTER_XTABLES && (IP6_NF_IPTABLES || IP6_NF_IPTABLES=n)
 794         depends on NETFILTER_ADVANCED
 795         help
 796           This option adds a `hashlimit' match.
 797
 798           As opposed to `limit', this match dynamically creates a hash table
 799           of limit buckets, based on your selection of source/destination
 800           addresses and/or ports.
 801
 802           It enables you to express policies like `10kpps for any given
 803           destination address' or `500pps from any given source address'
 804           with a single rule.
 805
 806 endmenu
 807