net/netfilter/Kconfig

   1 menu "Core Netfilter Configuration"
   2         depends on NET && INET && NETFILTER
   3
   4 config NETFILTER_NETLINK
   5        tristate "Netfilter netlink interface"
   6        help
   7          If this option is enabled, the kernel will include support
   8          for the new netfilter netlink interface.
   9
  10 config NETFILTER_NETLINK_QUEUE
  11         tristate "Netfilter NFQUEUE over NFNETLINK interface"
  12         depends on NETFILTER_NETLINK
  13         help
  14           If this option is enabled, the kernel will include support
  15           for queueing packets via NFNETLINK.
  16
  17 config NETFILTER_NETLINK_LOG
  18         tristate "Netfilter LOG over NFNETLINK interface"
  19         depends on NETFILTER_NETLINK
  20         help
  21           If this option is enabled, the kernel will include support
  22           for logging packets via NFNETLINK.
  23
  24           This obsoletes the existing ipt_ULOG and ebg_ulog mechanisms,
  25           and is also scheduled to replace the old syslog-based ipt_LOG
  26           and ip6t_LOG modules.
  27
  28 # Rename this to NF_CONNTRACK in a 2.6.25
  29 config NF_CONNTRACK_ENABLED
  30         tristate "Netfilter connection tracking support"
  31         help
  32           Connection tracking keeps a record of what packets have passed
  33           through your machine, in order to figure out how they are related
  34           into connections.
  35
  36           This is required to do Masquerading or other kinds of Network
  37           Address Translation (except for Fast NAT).  It can also be used to
  38           enhance packet filtering (see `Connection state match support'
  39           below).
  40
  41           To compile it as a module, choose M here.  If unsure, say N.
  42
  43 config NF_CONNTRACK
  44         tristate
  45         default NF_CONNTRACK_ENABLED
  46
  47 config NF_CT_ACCT
  48         bool "Connection tracking flow accounting"
  49         depends on NF_CONNTRACK
  50         help
  51           If this option is enabled, the connection tracking code will
  52           keep per-flow packet and byte counters.
  53
  54           Those counters can be used for flow-based accounting or the
  55           `connbytes' match.
  56
  57           If unsure, say `N'.
  58
  59 config NF_CONNTRACK_MARK
  60         bool  'Connection mark tracking support'
  61         depends on NF_CONNTRACK
  62         help
  63           This option enables support for connection marks, used by the
  64           `CONNMARK' target and `connmark' match. Similar to the mark value
  65           of packets, but this mark value is kept in the conntrack session
  66           instead of the individual packets.
  67
  68 config NF_CONNTRACK_SECMARK
  69         bool  'Connection tracking security mark support'
  70         depends on NF_CONNTRACK && NETWORK_SECMARK
  71         help
  72           This option enables security markings to be applied to
  73           connections.  Typically they are copied to connections from
  74           packets using the CONNSECMARK target and copied back from
  75           connections to packets with the same target, with the packets
  76           being originally labeled via SECMARK.
  77
  78           If unsure, say 'N'.
  79
  80 config NF_CONNTRACK_EVENTS
  81         bool "Connection tracking events (EXPERIMENTAL)"
  82         depends on EXPERIMENTAL && NF_CONNTRACK
  83         help
  84           If this option is enabled, the connection tracking code will
  85           provide a notifier chain that can be used by other kernel code
  86           to get notified about changes in the connection tracking state.
  87
  88           If unsure, say `N'.
  89
  90 config NF_CT_PROTO_GRE
  91         tristate
  92         depends on NF_CONNTRACK
  93
  94 config NF_CT_PROTO_SCTP
  95         tristate 'SCTP protocol connection tracking support (EXPERIMENTAL)'
  96         depends on EXPERIMENTAL && NF_CONNTRACK
  97         default n
  98         help
  99           With this option enabled, the layer 3 independent connection
 100           tracking code will be able to do state tracking on SCTP connections.
 101
 102           If you want to compile it as a module, say M here and read
 103           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 104
 105 config NF_CONNTRACK_AMANDA
 106         tristate "Amanda backup protocol support"
 107         depends on NF_CONNTRACK
 108         select TEXTSEARCH
 109         select TEXTSEARCH_KMP
 110         help
 111           If you are running the Amanda backup package <http://www.amanda.org/>
 112           on this machine or machines that will be MASQUERADED through this
 113           machine, then you may want to enable this feature.  This allows the
 114           connection tracking and natting code to allow the sub-channels that
 115           Amanda requires for communication of the backup data, messages and
 116           index.
 117
 118           To compile it as a module, choose M here.  If unsure, say N.
 119
 120 config NF_CONNTRACK_FTP
 121         tristate "FTP protocol support"
 122         depends on NF_CONNTRACK
 123         help
 124           Tracking FTP connections is problematic: special helpers are
 125           required for tracking them, and doing masquerading and other forms
 126           of Network Address Translation on them.
 127
 128           This is FTP support on Layer 3 independent connection tracking.
 129           Layer 3 independent connection tracking is experimental scheme
 130           which generalize ip_conntrack to support other layer 3 protocols.
 131
 132           To compile it as a module, choose M here.  If unsure, say N.
 133
 134 config NF_CONNTRACK_H323
 135         tristate "H.323 protocol support (EXPERIMENTAL)"
 136         depends on EXPERIMENTAL && NF_CONNTRACK && (IPV6 || IPV6=n)
 137         help
 138           H.323 is a VoIP signalling protocol from ITU-T. As one of the most
 139           important VoIP protocols, it is widely used by voice hardware and
 140           software including voice gateways, IP phones, Netmeeting, OpenPhone,
 141           Gnomemeeting, etc.
 142
 143           With this module you can support H.323 on a connection tracking/NAT
 144           firewall.
 145
 146           This module supports RAS, Fast Start, H.245 Tunnelling, Call
 147           Forwarding, RTP/RTCP and T.120 based audio, video, fax, chat,
 148           whiteboard, file transfer, etc. For more information, please
 149           visit http://nath323.sourceforge.net/.
 150
 151           To compile it as a module, choose M here.  If unsure, say N.
 152
 153 config NF_CONNTRACK_IRC
 154         tristate "IRC protocol support"
 155         depends on NF_CONNTRACK
 156         help
 157           There is a commonly-used extension to IRC called
 158           Direct Client-to-Client Protocol (DCC).  This enables users to send
 159           files to each other, and also chat to each other without the need
 160           of a server.  DCC Sending is used anywhere you send files over IRC,
 161           and DCC Chat is most commonly used by Eggdrop bots.  If you are
 162           using NAT, this extension will enable you to send files and initiate
 163           chats.  Note that you do NOT need this extension to get files or
 164           have others initiate chats, or everything else in IRC.
 165
 166           To compile it as a module, choose M here.  If unsure, say N.
 167
 168 config NF_CONNTRACK_NETBIOS_NS
 169         tristate "NetBIOS name service protocol support (EXPERIMENTAL)"
 170         depends on EXPERIMENTAL && NF_CONNTRACK
 171         help
 172           NetBIOS name service requests are sent as broadcast messages from an
 173           unprivileged port and responded to with unicast messages to the
 174           same port. This make them hard to firewall properly because connection
 175           tracking doesn't deal with broadcasts. This helper tracks locally
 176           originating NetBIOS name service requests and the corresponding
 177           responses. It relies on correct IP address configuration, specifically
 178           netmask and broadcast address. When properly configured, the output
 179           of "ip address show" should look similar to this:
 180
 181           $ ip -4 address show eth0
 182           4: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
 183               inet 172.16.2.252/24 brd 172.16.2.255 scope global eth0
 184
 185           To compile it as a module, choose M here.  If unsure, say N.
 186
 187 config NF_CONNTRACK_PPTP
 188         tristate "PPtP protocol support"
 189         depends on NF_CONNTRACK
 190         select NF_CT_PROTO_GRE
 191         help
 192           This module adds support for PPTP (Point to Point Tunnelling
 193           Protocol, RFC2637) connection tracking and NAT.
 194
 195           If you are running PPTP sessions over a stateful firewall or NAT
 196           box, you may want to enable this feature.
 197
 198           Please note that not all PPTP modes of operation are supported yet.
 199           Specifically these limitations exist:
 200             - Blindly assumes that control connections are always established
 201               in PNS->PAC direction. This is a violation of RFC2637.
 202             - Only supports a single call within each session
 203
 204           To compile it as a module, choose M here.  If unsure, say N.
 205
 206 config NF_CONNTRACK_SANE
 207         tristate "SANE protocol support (EXPERIMENTAL)"
 208         depends on EXPERIMENTAL && NF_CONNTRACK
 209         help
 210           SANE is a protocol for remote access to scanners as implemented
 211           by the 'saned' daemon. Like FTP, it uses separate control and
 212           data connections.
 213
 214           With this module you can support SANE on a connection tracking
 215           firewall.
 216
 217           To compile it as a module, choose M here.  If unsure, say N.
 218
 219 config NF_CONNTRACK_SIP
 220         tristate "SIP protocol support (EXPERIMENTAL)"
 221         depends on EXPERIMENTAL && NF_CONNTRACK
 222         help
 223           SIP is an application-layer control protocol that can establish,
 224           modify, and terminate multimedia sessions (conferences) such as
 225           Internet telephony calls. With the ip_conntrack_sip and
 226           the nf_nat_sip modules you can support the protocol on a connection
 227           tracking/NATing firewall.
 228
 229           To compile it as a module, choose M here.  If unsure, say N.
 230
 231 config NF_CONNTRACK_TFTP
 232         tristate "TFTP protocol support"
 233         depends on NF_CONNTRACK
 234         help
 235           TFTP connection tracking helper, this is required depending
 236           on how restrictive your ruleset is.
 237           If you are using a tftp client behind -j SNAT or -j MASQUERADING
 238           you will need this.
 239
 240           To compile it as a module, choose M here.  If unsure, say N.
 241
 242 config NF_CT_NETLINK
 243         tristate 'Connection tracking netlink interface (EXPERIMENTAL)'
 244         depends on EXPERIMENTAL && NF_CONNTRACK && NETFILTER_NETLINK
 245         depends on NF_CONNTRACK!=y || NETFILTER_NETLINK!=m
 246         depends on NF_NAT=n || NF_NAT
 247         help
 248           This option enables support for a netlink-based userspace interface
 249
 250 config NETFILTER_XTABLES
 251         tristate "Netfilter Xtables support (required for ip_tables)"
 252         help
 253           This is required if you intend to use any of ip_tables,
 254           ip6_tables or arp_tables.
 255
 256 # alphabetically ordered list of targets
 257
 258 config NETFILTER_XT_TARGET_CLASSIFY
 259         tristate '"CLASSIFY" target support'
 260         depends on NETFILTER_XTABLES
 261         help
 262           This option adds a `CLASSIFY' target, which enables the user to set
 263           the priority of a packet. Some qdiscs can use this value for
 264           classification, among these are:
 265
 266           atm, cbq, dsmark, pfifo_fast, htb, prio
 267
 268           To compile it as a module, choose M here.  If unsure, say N.
 269
 270 config NETFILTER_XT_TARGET_CONNMARK
 271         tristate  '"CONNMARK" target support'
 272         depends on NETFILTER_XTABLES
 273         depends on IP_NF_MANGLE || IP6_NF_MANGLE
 274         depends on NF_CONNTRACK
 275         select NF_CONNTRACK_MARK
 276         help
 277           This option adds a `CONNMARK' target, which allows one to manipulate
 278           the connection mark value.  Similar to the MARK target, but
 279           affects the connection mark value rather than the packet mark value.
 280
 281           If you want to compile it as a module, say M here and read
 282           <file:Documentation/kbuild/modules.txt>.  The module will be called
 283           ipt_CONNMARK.ko.  If unsure, say `N'.
 284
 285 config NETFILTER_XT_TARGET_DSCP
 286         tristate '"DSCP" target support'
 287         depends on NETFILTER_XTABLES
 288         depends on IP_NF_MANGLE || IP6_NF_MANGLE
 289         help
 290           This option adds a `DSCP' target, which allows you to manipulate
 291           the IPv4/IPv6 header DSCP field (differentiated services codepoint).
 292
 293           The DSCP field can have any value between 0x0 and 0x3f inclusive.
 294
 295           To compile it as a module, choose M here.  If unsure, say N.
 296
 297 config NETFILTER_XT_TARGET_MARK
 298         tristate '"MARK" target support'
 299         depends on NETFILTER_XTABLES
 300         help
 301           This option adds a `MARK' target, which allows you to create rules
 302           in the `mangle' table which alter the netfilter mark (nfmark) field
 303           associated with the packet prior to routing. This can change
 304           the routing method (see `Use netfilter MARK value as routing
 305           key') and can also be used by other subsystems to change their
 306           behavior.
 307
 308           To compile it as a module, choose M here.  If unsure, say N.
 309
 310 config NETFILTER_XT_TARGET_NFQUEUE
 311         tristate '"NFQUEUE" target Support'
 312         depends on NETFILTER_XTABLES
 313         help
 314           This target replaced the old obsolete QUEUE target.
 315
 316           As opposed to QUEUE, it supports 65535 different queues,
 317           not just one.
 318
 319           To compile it as a module, choose M here.  If unsure, say N.
 320
 321 config NETFILTER_XT_TARGET_NFLOG
 322         tristate '"NFLOG" target support'
 323         depends on NETFILTER_XTABLES
 324         help
 325           This option enables the NFLOG target, which allows to LOG
 326           messages through the netfilter logging API, which can use
 327           either the old LOG target, the old ULOG target or nfnetlink_log
 328           as backend.
 329
 330           To compile it as a module, choose M here.  If unsure, say N.
 331
 332 config NETFILTER_XT_TARGET_NOTRACK
 333         tristate  '"NOTRACK" target support'
 334         depends on NETFILTER_XTABLES
 335         depends on IP_NF_RAW || IP6_NF_RAW
 336         depends on NF_CONNTRACK
 337         help
 338           The NOTRACK target allows a select rule to specify
 339           which packets *not* to enter the conntrack/NAT
 340           subsystem with all the consequences (no ICMP error tracking,
 341           no protocol helpers for the selected packets).
 342
 343           If you want to compile it as a module, say M here and read
 344           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 345
 346 config NETFILTER_XT_TARGET_TRACE
 347         tristate  '"TRACE" target support'
 348         depends on NETFILTER_XTABLES
 349         depends on IP_NF_RAW || IP6_NF_RAW
 350         help
 351           The TRACE target allows you to mark packets so that the kernel
 352           will log every rule which match the packets as those traverse
 353           the tables, chains, rules.
 354
 355           If you want to compile it as a module, say M here and read
 356           <file:Documentation/modules.txt>.  If unsure, say `N'.
 357
 358 config NETFILTER_XT_TARGET_SECMARK
 359         tristate '"SECMARK" target support'
 360         depends on NETFILTER_XTABLES && NETWORK_SECMARK
 361         help
 362           The SECMARK target allows security marking of network
 363           packets, for use with security subsystems.
 364
 365           To compile it as a module, choose M here.  If unsure, say N.
 366
 367 config NETFILTER_XT_TARGET_CONNSECMARK
 368         tristate '"CONNSECMARK" target support'
 369         depends on NETFILTER_XTABLES && NF_CONNTRACK && NF_CONNTRACK_SECMARK
 370         help
 371           The CONNSECMARK target copies security markings from packets
 372           to connections, and restores security markings from connections
 373           to packets (if the packets are not already marked).  This would
 374           normally be used in conjunction with the SECMARK target.
 375
 376           To compile it as a module, choose M here.  If unsure, say N.
 377
 378 config NETFILTER_XT_TARGET_TCPMSS
 379         tristate '"TCPMSS" target support'
 380         depends on NETFILTER_XTABLES && (IPV6 || IPV6=n)
 381         ---help---
 382           This option adds a `TCPMSS' target, which allows you to alter the
 383           MSS value of TCP SYN packets, to control the maximum size for that
 384           connection (usually limiting it to your outgoing interface's MTU
 385           minus 40).
 386
 387           This is used to overcome criminally braindead ISPs or servers which
 388           block ICMP Fragmentation Needed packets.  The symptoms of this
 389           problem are that everything works fine from your Linux
 390           firewall/router, but machines behind it can never exchange large
 391           packets:
 392                 1) Web browsers connect, then hang with no data received.
 393                 2) Small mail works fine, but large emails hang.
 394                 3) ssh works fine, but scp hangs after initial handshaking.
 395
 396           Workaround: activate this option and add a rule to your firewall
 397           configuration like:
 398
 399           iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN \
 400                          -j TCPMSS --clamp-mss-to-pmtu
 401
 402           To compile it as a module, choose M here.  If unsure, say N.
 403
 404 config NETFILTER_XT_MATCH_COMMENT
 405         tristate  '"comment" match support'
 406         depends on NETFILTER_XTABLES
 407         help
 408           This option adds a `comment' dummy-match, which allows you to put
 409           comments in your iptables ruleset.
 410
 411           If you want to compile it as a module, say M here and read
 412           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 413
 414 config NETFILTER_XT_MATCH_CONNBYTES
 415         tristate  '"connbytes" per-connection counter match support'
 416         depends on NETFILTER_XTABLES
 417         depends on NF_CONNTRACK
 418         select NF_CT_ACCT
 419         help
 420           This option adds a `connbytes' match, which allows you to match the
 421           number of bytes and/or packets for each direction within a connection.
 422
 423           If you want to compile it as a module, say M here and read
 424           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 425
 426 config NETFILTER_XT_MATCH_CONNMARK
 427         tristate  '"connmark" connection mark match support'
 428         depends on NETFILTER_XTABLES
 429         depends on NF_CONNTRACK
 430         select NF_CONNTRACK_MARK
 431         help
 432           This option adds a `connmark' match, which allows you to match the
 433           connection mark value previously set for the session by `CONNMARK'.
 434
 435           If you want to compile it as a module, say M here and read
 436           <file:Documentation/kbuild/modules.txt>.  The module will be called
 437           ipt_connmark.ko.  If unsure, say `N'.
 438
 439 config NETFILTER_XT_MATCH_CONNTRACK
 440         tristate '"conntrack" connection tracking match support'
 441         depends on NETFILTER_XTABLES
 442         depends on NF_CONNTRACK
 443         help
 444           This is a general conntrack match module, a superset of the state match.
 445
 446           It allows matching on additional conntrack information, which is
 447           useful in complex configurations, such as NAT gateways with multiple
 448           internet links or tunnels.
 449
 450           To compile it as a module, choose M here.  If unsure, say N.
 451
 452 config NETFILTER_XT_MATCH_DCCP
 453         tristate  '"DCCP" protocol match support'
 454         depends on NETFILTER_XTABLES
 455         help
 456           With this option enabled, you will be able to use the iptables
 457           `dccp' match in order to match on DCCP source/destination ports
 458           and DCCP flags.
 459
 460           If you want to compile it as a module, say M here and read
 461           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 462
 463 config NETFILTER_XT_MATCH_DSCP
 464         tristate '"DSCP" match support'
 465         depends on NETFILTER_XTABLES
 466         help
 467           This option adds a `DSCP' match, which allows you to match against
 468           the IPv4/IPv6 header DSCP field (differentiated services codepoint).
 469
 470           The DSCP field can have any value between 0x0 and 0x3f inclusive.
 471
 472           To compile it as a module, choose M here.  If unsure, say N.
 473
 474 config NETFILTER_XT_MATCH_ESP
 475         tristate '"ESP" match support'
 476         depends on NETFILTER_XTABLES
 477         help
 478           This match extension allows you to match a range of SPIs
 479           inside ESP header of IPSec packets.
 480
 481           To compile it as a module, choose M here.  If unsure, say N.
 482
 483 config NETFILTER_XT_MATCH_HELPER
 484         tristate '"helper" match support'
 485         depends on NETFILTER_XTABLES
 486         depends on NF_CONNTRACK
 487         help
 488           Helper matching allows you to match packets in dynamic connections
 489           tracked by a conntrack-helper, ie. ip_conntrack_ftp
 490
 491           To compile it as a module, choose M here.  If unsure, say Y.
 492
 493 config NETFILTER_XT_MATCH_LENGTH
 494         tristate '"length" match support'
 495         depends on NETFILTER_XTABLES
 496         help
 497           This option allows you to match the length of a packet against a
 498           specific value or range of values.
 499
 500           To compile it as a module, choose M here.  If unsure, say N.
 501
 502 config NETFILTER_XT_MATCH_LIMIT
 503         tristate '"limit" match support'
 504         depends on NETFILTER_XTABLES
 505         help
 506           limit matching allows you to control the rate at which a rule can be
 507           matched: mainly useful in combination with the LOG target ("LOG
 508           target support", below) and to avoid some Denial of Service attacks.
 509
 510           To compile it as a module, choose M here.  If unsure, say N.
 511
 512 config NETFILTER_XT_MATCH_MAC
 513         tristate '"mac" address match support'
 514         depends on NETFILTER_XTABLES
 515         help
 516           MAC matching allows you to match packets based on the source
 517           Ethernet address of the packet.
 518
 519           To compile it as a module, choose M here.  If unsure, say N.
 520
 521 config NETFILTER_XT_MATCH_MARK
 522         tristate '"mark" match support'
 523         depends on NETFILTER_XTABLES
 524         help
 525           Netfilter mark matching allows you to match packets based on the
 526           `nfmark' value in the packet.  This can be set by the MARK target
 527           (see below).
 528
 529           To compile it as a module, choose M here.  If unsure, say N.
 530
 531 config NETFILTER_XT_MATCH_POLICY
 532         tristate 'IPsec "policy" match support'
 533         depends on NETFILTER_XTABLES && XFRM
 534         help
 535           Policy matching allows you to match packets based on the
 536           IPsec policy that was used during decapsulation/will
 537           be used during encapsulation.
 538
 539           To compile it as a module, choose M here.  If unsure, say N.
 540
 541 config NETFILTER_XT_MATCH_MULTIPORT
 542         tristate "Multiple port match support"
 543         depends on NETFILTER_XTABLES
 544         help
 545           Multiport matching allows you to match TCP or UDP packets based on
 546           a series of source or destination ports: normally a rule can only
 547           match a single range of ports.
 548
 549           To compile it as a module, choose M here.  If unsure, say N.
 550
 551 config NETFILTER_XT_MATCH_PHYSDEV
 552         tristate '"physdev" match support'
 553         depends on NETFILTER_XTABLES && BRIDGE && BRIDGE_NETFILTER
 554         help
 555           Physdev packet matching matches against the physical bridge ports
 556           the IP packet arrived on or will leave by.
 557
 558           To compile it as a module, choose M here.  If unsure, say N.
 559
 560 config NETFILTER_XT_MATCH_PKTTYPE
 561         tristate '"pkttype" packet type match support'
 562         depends on NETFILTER_XTABLES
 563         help
 564           Packet type matching allows you to match a packet by
 565           its "class", eg. BROADCAST, MULTICAST, ...
 566
 567           Typical usage:
 568           iptables -A INPUT -m pkttype --pkt-type broadcast -j LOG
 569
 570           To compile it as a module, choose M here.  If unsure, say N.
 571
 572 config NETFILTER_XT_MATCH_QUOTA
 573         tristate '"quota" match support'
 574         depends on NETFILTER_XTABLES
 575         help
 576           This option adds a `quota' match, which allows to match on a
 577           byte counter.
 578
 579           If you want to compile it as a module, say M here and read
 580           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 581
 582 config NETFILTER_XT_MATCH_REALM
 583         tristate  '"realm" match support'
 584         depends on NETFILTER_XTABLES
 585         select NET_CLS_ROUTE
 586         help
 587           This option adds a `realm' match, which allows you to use the realm
 588           key from the routing subsystem inside iptables.
 589
 590           This match pretty much resembles the CONFIG_NET_CLS_ROUTE4 option
 591           in tc world.
 592
 593           If you want to compile it as a module, say M here and read
 594           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 595
 596 config NETFILTER_XT_MATCH_SCTP
 597         tristate  '"sctp" protocol match support (EXPERIMENTAL)'
 598         depends on NETFILTER_XTABLES && EXPERIMENTAL
 599         help
 600           With this option enabled, you will be able to use the
 601           `sctp' match in order to match on SCTP source/destination ports
 602           and SCTP chunk types.
 603
 604           If you want to compile it as a module, say M here and read
 605           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 606
 607 config NETFILTER_XT_MATCH_STATE
 608         tristate '"state" match support'
 609         depends on NETFILTER_XTABLES
 610         depends on NF_CONNTRACK
 611         help
 612           Connection state matching allows you to match packets based on their
 613           relationship to a tracked connection (ie. previous packets).  This
 614           is a powerful tool for packet classification.
 615
 616           To compile it as a module, choose M here.  If unsure, say N.
 617
 618 config NETFILTER_XT_MATCH_STATISTIC
 619         tristate '"statistic" match support'
 620         depends on NETFILTER_XTABLES
 621         help
 622           This option adds a `statistic' match, which allows you to match
 623           on packets periodically or randomly with a given percentage.
 624
 625           To compile it as a module, choose M here.  If unsure, say N.
 626
 627 config NETFILTER_XT_MATCH_STRING
 628         tristate  '"string" match support'
 629         depends on NETFILTER_XTABLES
 630         select TEXTSEARCH
 631         select TEXTSEARCH_KMP
 632         select TEXTSEARCH_BM
 633         select TEXTSEARCH_FSM
 634         help
 635           This option adds a `string' match, which allows you to look for
 636           pattern matchings in packets.
 637
 638           To compile it as a module, choose M here.  If unsure, say N.
 639
 640 config NETFILTER_XT_MATCH_TCPMSS
 641         tristate '"tcpmss" match support'
 642         depends on NETFILTER_XTABLES
 643         help
 644           This option adds a `tcpmss' match, which allows you to examine the
 645           MSS value of TCP SYN packets, which control the maximum packet size
 646           for that connection.
 647
 648           To compile it as a module, choose M here.  If unsure, say N.
 649
 650 config NETFILTER_XT_MATCH_U32
 651         tristate '"u32" match support'
 652         depends on NETFILTER_XTABLES
 653         ---help---
 654           u32 allows you to extract quantities of up to 4 bytes from a packet,
 655           AND them with specified masks, shift them by specified amounts and
 656           test whether the results are in any of a set of specified ranges.
 657           The specification of what to extract is general enough to skip over
 658           headers with lengths stored in the packet, as in IP or TCP header
 659           lengths.
 660
 661           Details and examples are in the kernel module source.
 662
 663 config NETFILTER_XT_MATCH_HASHLIMIT
 664         tristate '"hashlimit" match support'
 665         depends on NETFILTER_XTABLES && (IP6_NF_IPTABLES || IP6_NF_IPTABLES=n)
 666         help
 667           This option adds a `hashlimit' match.
 668
 669           As opposed to `limit', this match dynamically creates a hash table
 670           of limit buckets, based on your selection of source/destination
 671           addresses and/or ports.
 672
 673           It enables you to express policies like `10kpps for any given
 674           destination address' or `500pps from any given source address'
 675           with a single rule.
 676
 677 endmenu
 678