net/ipv4/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 #
   3 # IP configuration
   4 #
   5 config IP_MULTICAST
   6         bool "IP: multicasting"
   7         help
   8           This is code for addressing several networked computers at once,
   9           enlarging your kernel by about 2 KB. You need multicasting if you
  10           intend to participate in the MBONE, a high bandwidth network on top
  11           of the Internet which carries audio and video broadcasts. More
  12           information about the MBONE is on the WWW at
  13           <https://www.savetz.com/mbone/>. For most people, it's safe to say N.
  14
  15 config IP_ADVANCED_ROUTER
  16         bool "IP: advanced router"
  17         help
  18           If you intend to run your Linux box mostly as a router, i.e. as a
  19           computer that forwards and redistributes network packets, say Y; you
  20           will then be presented with several options that allow more precise
  21           control about the routing process.
  22
  23           The answer to this question won't directly affect the kernel:
  24           answering N will just cause the configurator to skip all the
  25           questions about advanced routing.
  26
  27           Note that your box can only act as a router if you enable IP
  28           forwarding in your kernel; you can do that by saying Y to "/proc
  29           file system support" and "Sysctl support" below and executing the
  30           line
  31
  32           echo "1" > /proc/sys/net/ipv4/ip_forward
  33
  34           at boot time after the /proc file system has been mounted.
  35
  36           If you turn on IP forwarding, you should consider the rp_filter, which
  37           automatically rejects incoming packets if the routing table entry
  38           for their source address doesn't match the network interface they're
  39           arriving on. This has security advantages because it prevents the
  40           so-called IP spoofing, however it can pose problems if you use
  41           asymmetric routing (packets from you to a host take a different path
  42           than packets from that host to you) or if you operate a non-routing
  43           host which has several IP addresses on different interfaces. To turn
  44           rp_filter on use:
  45
  46           echo 1 > /proc/sys/net/ipv4/conf/<device>/rp_filter
  47            or
  48           echo 1 > /proc/sys/net/ipv4/conf/all/rp_filter
  49
  50           Note that some distributions enable it in startup scripts.
  51           For details about rp_filter strict and loose mode read
  52           <file:Documentation/networking/ip-sysctl.rst>.
  53
  54           If unsure, say N here.
  55
  56 config IP_FIB_TRIE_STATS
  57         bool "FIB TRIE statistics"
  58         depends on IP_ADVANCED_ROUTER
  59         help
  60           Keep track of statistics on structure of FIB TRIE table.
  61           Useful for testing and measuring TRIE performance.
  62
  63 config IP_MULTIPLE_TABLES
  64         bool "IP: policy routing"
  65         depends on IP_ADVANCED_ROUTER
  66         select FIB_RULES
  67         help
  68           Normally, a router decides what to do with a received packet based
  69           solely on the packet's final destination address. If you say Y here,
  70           the Linux router will also be able to take the packet's source
  71           address into account. Furthermore, the TOS (Type-Of-Service) field
  72           of the packet can be used for routing decisions as well.
  73
  74           If you need more information, see the Linux Advanced
  75           Routing and Traffic Control documentation at
  76           <https://lartc.org/howto/lartc.rpdb.html>
  77
  78           If unsure, say N.
  79
  80 config IP_ROUTE_MULTIPATH
  81         bool "IP: equal cost multipath"
  82         depends on IP_ADVANCED_ROUTER
  83         help
  84           Normally, the routing tables specify a single action to be taken in
  85           a deterministic manner for a given packet. If you say Y here
  86           however, it becomes possible to attach several actions to a packet
  87           pattern, in effect specifying several alternative paths to travel
  88           for those packets. The router considers all these paths to be of
  89           equal "cost" and chooses one of them in a non-deterministic fashion
  90           if a matching packet arrives.
  91
  92 config IP_ROUTE_VERBOSE
  93         bool "IP: verbose route monitoring"
  94         depends on IP_ADVANCED_ROUTER
  95         help
  96           If you say Y here, which is recommended, then the kernel will print
  97           verbose messages regarding the routing, for example warnings about
  98           received packets which look strange and could be evidence of an
  99           attack or a misconfigured system somewhere. The information is
 100           handled by the klogd daemon which is responsible for kernel messages
 101           ("man klogd").
 102
 103 config IP_ROUTE_CLASSID
 104         bool
 105
 106 config IP_PNP
 107         bool "IP: kernel level autoconfiguration"
 108         help
 109           This enables automatic configuration of IP addresses of devices and
 110           of the routing table during kernel boot, based on either information
 111           supplied on the kernel command line or by BOOTP or RARP protocols.
 112           You need to say Y only for diskless machines requiring network
 113           access to boot (in which case you want to say Y to "Root file system
 114           on NFS" as well), because all other machines configure the network
 115           in their startup scripts.
 116
 117 config IP_PNP_DHCP
 118         bool "IP: DHCP support"
 119         depends on IP_PNP
 120         help
 121           If you want your Linux box to mount its whole root file system (the
 122           one containing the directory /) from some other computer over the
 123           net via NFS and you want the IP address of your computer to be
 124           discovered automatically at boot time using the DHCP protocol (a
 125           special protocol designed for doing this job), say Y here. In case
 126           the boot ROM of your network card was designed for booting Linux and
 127           does DHCP itself, providing all necessary information on the kernel
 128           command line, you can say N here.
 129
 130           If unsure, say Y. Note that if you want to use DHCP, a DHCP server
 131           must be operating on your network.  Read
 132           <file:Documentation/admin-guide/nfs/nfsroot.rst> for details.
 133
 134 config IP_PNP_BOOTP
 135         bool "IP: BOOTP support"
 136         depends on IP_PNP
 137         help
 138           If you want your Linux box to mount its whole root file system (the
 139           one containing the directory /) from some other computer over the
 140           net via NFS and you want the IP address of your computer to be
 141           discovered automatically at boot time using the BOOTP protocol (a
 142           special protocol designed for doing this job), say Y here. In case
 143           the boot ROM of your network card was designed for booting Linux and
 144           does BOOTP itself, providing all necessary information on the kernel
 145           command line, you can say N here. If unsure, say Y. Note that if you
 146           want to use BOOTP, a BOOTP server must be operating on your network.
 147           Read <file:Documentation/admin-guide/nfs/nfsroot.rst> for details.
 148
 149 config IP_PNP_RARP
 150         bool "IP: RARP support"
 151         depends on IP_PNP
 152         help
 153           If you want your Linux box to mount its whole root file system (the
 154           one containing the directory /) from some other computer over the
 155           net via NFS and you want the IP address of your computer to be
 156           discovered automatically at boot time using the RARP protocol (an
 157           older protocol which is being obsoleted by BOOTP and DHCP), say Y
 158           here. Note that if you want to use RARP, a RARP server must be
 159           operating on your network. Read
 160           <file:Documentation/admin-guide/nfs/nfsroot.rst> for details.
 161
 162 config NET_IPIP
 163         tristate "IP: tunneling"
 164         select INET_TUNNEL
 165         select NET_IP_TUNNEL
 166         help
 167           Tunneling means encapsulating data of one protocol type within
 168           another protocol and sending it over a channel that understands the
 169           encapsulating protocol. This particular tunneling driver implements
 170           encapsulation of IP within IP, which sounds kind of pointless, but
 171           can be useful if you want to make your (or some other) machine
 172           appear on a different network than it physically is, or to use
 173           mobile-IP facilities (allowing laptops to seamlessly move between
 174           networks without changing their IP addresses).
 175
 176           Saying Y to this option will produce two modules ( = code which can
 177           be inserted in and removed from the running kernel whenever you
 178           want). Most people won't need this and can say N.
 179
 180 config NET_IPGRE_DEMUX
 181         tristate "IP: GRE demultiplexer"
 182         help
 183           This is helper module to demultiplex GRE packets on GRE version field criteria.
 184           Required by ip_gre and pptp modules.
 185
 186 config NET_IP_TUNNEL
 187         tristate
 188         select DST_CACHE
 189         select GRO_CELLS
 190         default n
 191
 192 config NET_IPGRE
 193         tristate "IP: GRE tunnels over IP"
 194         depends on (IPV6 || IPV6=n) && NET_IPGRE_DEMUX
 195         select NET_IP_TUNNEL
 196         help
 197           Tunneling means encapsulating data of one protocol type within
 198           another protocol and sending it over a channel that understands the
 199           encapsulating protocol. This particular tunneling driver implements
 200           GRE (Generic Routing Encapsulation) and at this time allows
 201           encapsulating of IPv4 or IPv6 over existing IPv4 infrastructure.
 202           This driver is useful if the other endpoint is a Cisco router: Cisco
 203           likes GRE much better than the other Linux tunneling driver ("IP
 204           tunneling" above). In addition, GRE allows multicast redistribution
 205           through the tunnel.
 206
 207 config NET_IPGRE_BROADCAST
 208         bool "IP: broadcast GRE over IP"
 209         depends on IP_MULTICAST && NET_IPGRE
 210         help
 211           One application of GRE/IP is to construct a broadcast WAN (Wide Area
 212           Network), which looks like a normal Ethernet LAN (Local Area
 213           Network), but can be distributed all over the Internet. If you want
 214           to do that, say Y here and to "IP multicast routing" below.
 215
 216 config IP_MROUTE_COMMON
 217         bool
 218         depends on IP_MROUTE || IPV6_MROUTE
 219
 220 config IP_MROUTE
 221         bool "IP: multicast routing"
 222         depends on IP_MULTICAST
 223         select IP_MROUTE_COMMON
 224         help
 225           This is used if you want your machine to act as a router for IP
 226           packets that have several destination addresses. It is needed on the
 227           MBONE, a high bandwidth network on top of the Internet which carries
 228           audio and video broadcasts. In order to do that, you would most
 229           likely run the program mrouted. If you haven't heard about it, you
 230           don't need it.
 231
 232 config IP_MROUTE_MULTIPLE_TABLES
 233         bool "IP: multicast policy routing"
 234         depends on IP_MROUTE && IP_ADVANCED_ROUTER
 235         select FIB_RULES
 236         help
 237           Normally, a multicast router runs a userspace daemon and decides
 238           what to do with a multicast packet based on the source and
 239           destination addresses. If you say Y here, the multicast router
 240           will also be able to take interfaces and packet marks into
 241           account and run multiple instances of userspace daemons
 242           simultaneously, each one handling a single table.
 243
 244           If unsure, say N.
 245
 246 config IP_PIMSM_V1
 247         bool "IP: PIM-SM version 1 support"
 248         depends on IP_MROUTE
 249         help
 250           Kernel side support for Sparse Mode PIM (Protocol Independent
 251           Multicast) version 1. This multicast routing protocol is used widely
 252           because Cisco supports it. You need special software to use it
 253           (pimd-v1). Please see <http://netweb.usc.edu/pim/> for more
 254           information about PIM.
 255
 256           Say Y if you want to use PIM-SM v1. Note that you can say N here if
 257           you just want to use Dense Mode PIM.
 258
 259 config IP_PIMSM_V2
 260         bool "IP: PIM-SM version 2 support"
 261         depends on IP_MROUTE
 262         help
 263           Kernel side support for Sparse Mode PIM version 2. In order to use
 264           this, you need an experimental routing daemon supporting it (pimd or
 265           gated-5). This routing protocol is not used widely, so say N unless
 266           you want to play with it.
 267
 268 config SYN_COOKIES
 269         bool "IP: TCP syncookie support"
 270         help
 271           Normal TCP/IP networking is open to an attack known as "SYN
 272           flooding". This denial-of-service attack prevents legitimate remote
 273           users from being able to connect to your computer during an ongoing
 274           attack and requires very little work from the attacker, who can
 275           operate from anywhere on the Internet.
 276
 277           SYN cookies provide protection against this type of attack. If you
 278           say Y here, the TCP/IP stack will use a cryptographic challenge
 279           protocol known as "SYN cookies" to enable legitimate users to
 280           continue to connect, even when your machine is under attack. There
 281           is no need for the legitimate users to change their TCP/IP software;
 282           SYN cookies work transparently to them. For technical information
 283           about SYN cookies, check out <https://cr.yp.to/syncookies.html>.
 284
 285           If you are SYN flooded, the source address reported by the kernel is
 286           likely to have been forged by the attacker; it is only reported as
 287           an aid in tracing the packets to their actual source and should not
 288           be taken as absolute truth.
 289
 290           SYN cookies may prevent correct error reporting on clients when the
 291           server is really overloaded. If this happens frequently better turn
 292           them off.
 293
 294           If you say Y here, you can disable SYN cookies at run time by
 295           saying Y to "/proc file system support" and
 296           "Sysctl support" below and executing the command
 297
 298           echo 0 > /proc/sys/net/ipv4/tcp_syncookies
 299
 300           after the /proc file system has been mounted.
 301
 302           If unsure, say N.
 303
 304 config NET_IPVTI
 305         tristate "Virtual (secure) IP: tunneling"
 306         depends on IPV6 || IPV6=n
 307         select INET_TUNNEL
 308         select NET_IP_TUNNEL
 309         select XFRM
 310         help
 311           Tunneling means encapsulating data of one protocol type within
 312           another protocol and sending it over a channel that understands the
 313           encapsulating protocol. This can be used with xfrm mode tunnel to give
 314           the notion of a secure tunnel for IPSEC and then use routing protocol
 315           on top.
 316
 317 config NET_UDP_TUNNEL
 318         tristate
 319         select NET_IP_TUNNEL
 320         default n
 321
 322 config NET_FOU
 323         tristate "IP: Foo (IP protocols) over UDP"
 324         select XFRM
 325         select NET_UDP_TUNNEL
 326         help
 327           Foo over UDP allows any IP protocol to be directly encapsulated
 328           over UDP include tunnels (IPIP, GRE, SIT). By encapsulating in UDP
 329           network mechanisms and optimizations for UDP (such as ECMP
 330           and RSS) can be leveraged to provide better service.
 331
 332 config NET_FOU_IP_TUNNELS
 333         bool "IP: FOU encapsulation of IP tunnels"
 334         depends on NET_IPIP || NET_IPGRE || IPV6_SIT
 335         select NET_FOU
 336         help
 337           Allow configuration of FOU or GUE encapsulation for IP tunnels.
 338           When this option is enabled IP tunnels can be configured to use
 339           FOU or GUE encapsulation.
 340
 341 config INET_AH
 342         tristate "IP: AH transformation"
 343         select XFRM_AH
 344         help
 345           Support for IPsec AH (Authentication Header).
 346
 347           AH can be used with various authentication algorithms.  Besides
 348           enabling AH support itself, this option enables the generic
 349           implementations of the algorithms that RFC 8221 lists as MUST be
 350           implemented.  If you need any other algorithms, you'll need to enable
 351           them in the crypto API.  You should also enable accelerated
 352           implementations of any needed algorithms when available.
 353
 354           If unsure, say Y.
 355
 356 config INET_ESP
 357         tristate "IP: ESP transformation"
 358         select XFRM_ESP
 359         help
 360           Support for IPsec ESP (Encapsulating Security Payload).
 361
 362           ESP can be used with various encryption and authentication algorithms.
 363           Besides enabling ESP support itself, this option enables the generic
 364           implementations of the algorithms that RFC 8221 lists as MUST be
 365           implemented.  If you need any other algorithms, you'll need to enable
 366           them in the crypto API.  You should also enable accelerated
 367           implementations of any needed algorithms when available.
 368
 369           If unsure, say Y.
 370
 371 config INET_ESP_OFFLOAD
 372         tristate "IP: ESP transformation offload"
 373         depends on INET_ESP
 374         select XFRM_OFFLOAD
 375         default n
 376         help
 377           Support for ESP transformation offload. This makes sense
 378           only if this system really does IPsec and want to do it
 379           with high throughput. A typical desktop system does not
 380           need it, even if it does IPsec.
 381
 382           If unsure, say N.
 383
 384 config INET_ESPINTCP
 385         bool "IP: ESP in TCP encapsulation (RFC 8229)"
 386         depends on XFRM && INET_ESP
 387         select STREAM_PARSER
 388         select NET_SOCK_MSG
 389         select XFRM_ESPINTCP
 390         help
 391           Support for RFC 8229 encapsulation of ESP and IKE over
 392           TCP/IPv4 sockets.
 393
 394           If unsure, say N.
 395
 396 config INET_IPCOMP
 397         tristate "IP: IPComp transformation"
 398         select INET_XFRM_TUNNEL
 399         select XFRM_IPCOMP
 400         help
 401           Support for IP Payload Compression Protocol (IPComp) (RFC3173),
 402           typically needed for IPsec.
 403
 404           If unsure, say Y.
 405
 406 config INET_XFRM_TUNNEL
 407         tristate
 408         select INET_TUNNEL
 409         default n
 410
 411 config INET_TUNNEL
 412         tristate
 413         default n
 414
 415 config INET_DIAG
 416         tristate "INET: socket monitoring interface"
 417         default y
 418         help
 419           Support for INET (TCP, DCCP, etc) socket monitoring interface used by
 420           native Linux tools such as ss. ss is included in iproute2, currently
 421           downloadable at:
 422
 423             http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2
 424
 425           If unsure, say Y.
 426
 427 config INET_TCP_DIAG
 428         depends on INET_DIAG
 429         def_tristate INET_DIAG
 430
 431 config INET_UDP_DIAG
 432         tristate "UDP: socket monitoring interface"
 433         depends on INET_DIAG && (IPV6 || IPV6=n)
 434         default n
 435         help
 436           Support for UDP socket monitoring interface used by the ss tool.
 437           If unsure, say Y.
 438
 439 config INET_RAW_DIAG
 440         tristate "RAW: socket monitoring interface"
 441         depends on INET_DIAG && (IPV6 || IPV6=n)
 442         default n
 443         help
 444           Support for RAW socket monitoring interface used by the ss tool.
 445           If unsure, say Y.
 446
 447 config INET_DIAG_DESTROY
 448         bool "INET: allow privileged process to administratively close sockets"
 449         depends on INET_DIAG
 450         default n
 451         help
 452           Provides a SOCK_DESTROY operation that allows privileged processes
 453           (e.g., a connection manager or a network administration tool such as
 454           ss) to close sockets opened by other processes. Closing a socket in
 455           this way interrupts any blocking read/write/connect operations on
 456           the socket and causes future socket calls to behave as if the socket
 457           had been disconnected.
 458           If unsure, say N.
 459
 460 menuconfig TCP_CONG_ADVANCED
 461         bool "TCP: advanced congestion control"
 462         help
 463           Support for selection of various TCP congestion control
 464           modules.
 465
 466           Nearly all users can safely say no here, and a safe default
 467           selection will be made (CUBIC with new Reno as a fallback).
 468
 469           If unsure, say N.
 470
 471 if TCP_CONG_ADVANCED
 472
 473 config TCP_CONG_BIC
 474         tristate "Binary Increase Congestion (BIC) control"
 475         default m
 476         help
 477           BIC-TCP is a sender-side only change that ensures a linear RTT
 478           fairness under large windows while offering both scalability and
 479           bounded TCP-friendliness. The protocol combines two schemes
 480           called additive increase and binary search increase. When the
 481           congestion window is large, additive increase with a large
 482           increment ensures linear RTT fairness as well as good
 483           scalability. Under small congestion windows, binary search
 484           increase provides TCP friendliness.
 485           See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/
 486
 487 config TCP_CONG_CUBIC
 488         tristate "CUBIC TCP"
 489         default y
 490         help
 491           This is version 2.0 of BIC-TCP which uses a cubic growth function
 492           among other techniques.
 493           See http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf
 494
 495 config TCP_CONG_WESTWOOD
 496         tristate "TCP Westwood+"
 497         default m
 498         help
 499           TCP Westwood+ is a sender-side only modification of the TCP Reno
 500           protocol stack that optimizes the performance of TCP congestion
 501           control. It is based on end-to-end bandwidth estimation to set
 502           congestion window and slow start threshold after a congestion
 503           episode. Using this estimation, TCP Westwood+ adaptively sets a
 504           slow start threshold and a congestion window which takes into
 505           account the bandwidth used  at the time congestion is experienced.
 506           TCP Westwood+ significantly increases fairness wrt TCP Reno in
 507           wired networks and throughput over wireless links.
 508
 509 config TCP_CONG_HTCP
 510         tristate "H-TCP"
 511         default m
 512         help
 513           H-TCP is a send-side only modifications of the TCP Reno
 514           protocol stack that optimizes the performance of TCP
 515           congestion control for high speed network links. It uses a
 516           modeswitch to change the alpha and beta parameters of TCP Reno
 517           based on network conditions and in a way so as to be fair with
 518           other Reno and H-TCP flows.
 519
 520 config TCP_CONG_HSTCP
 521         tristate "High Speed TCP"
 522         default n
 523         help
 524           Sally Floyd's High Speed TCP (RFC 3649) congestion control.
 525           A modification to TCP's congestion control mechanism for use
 526           with large congestion windows. A table indicates how much to
 527           increase the congestion window by when an ACK is received.
 528           For more detail see https://www.icir.org/floyd/hstcp.html
 529
 530 config TCP_CONG_HYBLA
 531         tristate "TCP-Hybla congestion control algorithm"
 532         default n
 533         help
 534           TCP-Hybla is a sender-side only change that eliminates penalization of
 535           long-RTT, large-bandwidth connections, like when satellite legs are
 536           involved, especially when sharing a common bottleneck with normal
 537           terrestrial connections.
 538
 539 config TCP_CONG_VEGAS
 540         tristate "TCP Vegas"
 541         default n
 542         help
 543           TCP Vegas is a sender-side only change to TCP that anticipates
 544           the onset of congestion by estimating the bandwidth. TCP Vegas
 545           adjusts the sending rate by modifying the congestion
 546           window. TCP Vegas should provide less packet loss, but it is
 547           not as aggressive as TCP Reno.
 548
 549 config TCP_CONG_NV
 550         tristate "TCP NV"
 551         default n
 552         help
 553           TCP NV is a follow up to TCP Vegas. It has been modified to deal with
 554           10G networks, measurement noise introduced by LRO, GRO and interrupt
 555           coalescence. In addition, it will decrease its cwnd multiplicatively
 556           instead of linearly.
 557
 558           Note that in general congestion avoidance (cwnd decreased when # packets
 559           queued grows) cannot coexist with congestion control (cwnd decreased only
 560           when there is packet loss) due to fairness issues. One scenario when they
 561           can coexist safely is when the CA flows have RTTs << CC flows RTTs.
 562
 563           For further details see http://www.brakmo.org/networking/tcp-nv/
 564
 565 config TCP_CONG_SCALABLE
 566         tristate "Scalable TCP"
 567         default n
 568         help
 569           Scalable TCP is a sender-side only change to TCP which uses a
 570           MIMD congestion control algorithm which has some nice scaling
 571           properties, though is known to have fairness issues.
 572           See http://www.deneholme.net/tom/scalable/
 573
 574 config TCP_CONG_LP
 575         tristate "TCP Low Priority"
 576         default n
 577         help
 578           TCP Low Priority (TCP-LP), a distributed algorithm whose goal is
 579           to utilize only the excess network bandwidth as compared to the
 580           ``fair share`` of bandwidth as targeted by TCP.
 581           See http://www-ece.rice.edu/networks/TCP-LP/
 582
 583 config TCP_CONG_VENO
 584         tristate "TCP Veno"
 585         default n
 586         help
 587           TCP Veno is a sender-side only enhancement of TCP to obtain better
 588           throughput over wireless networks. TCP Veno makes use of state
 589           distinguishing to circumvent the difficult judgment of the packet loss
 590           type. TCP Veno cuts down less congestion window in response to random
 591           loss packets.
 592           See <http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1177186>
 593
 594 config TCP_CONG_YEAH
 595         tristate "YeAH TCP"
 596         select TCP_CONG_VEGAS
 597         default n
 598         help
 599           YeAH-TCP is a sender-side high-speed enabled TCP congestion control
 600           algorithm, which uses a mixed loss/delay approach to compute the
 601           congestion window. It's design goals target high efficiency,
 602           internal, RTT and Reno fairness, resilience to link loss while
 603           keeping network elements load as low as possible.
 604
 605           For further details look here:
 606             http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf
 607
 608 config TCP_CONG_ILLINOIS
 609         tristate "TCP Illinois"
 610         default n
 611         help
 612           TCP-Illinois is a sender-side modification of TCP Reno for
 613           high speed long delay links. It uses round-trip-time to
 614           adjust the alpha and beta parameters to achieve a higher average
 615           throughput and maintain fairness.
 616
 617           For further details see:
 618             http://www.ews.uiuc.edu/~shaoliu/tcpillinois/index.html
 619
 620 config TCP_CONG_DCTCP
 621         tristate "DataCenter TCP (DCTCP)"
 622         default n
 623         help
 624           DCTCP leverages Explicit Congestion Notification (ECN) in the network to
 625           provide multi-bit feedback to the end hosts. It is designed to provide:
 626
 627           - High burst tolerance (incast due to partition/aggregate),
 628           - Low latency (short flows, queries),
 629           - High throughput (continuous data updates, large file transfers) with
 630             commodity, shallow-buffered switches.
 631
 632           All switches in the data center network running DCTCP must support
 633           ECN marking and be configured for marking when reaching defined switch
 634           buffer thresholds. The default ECN marking threshold heuristic for
 635           DCTCP on switches is 20 packets (30KB) at 1Gbps, and 65 packets
 636           (~100KB) at 10Gbps, but might need further careful tweaking.
 637
 638           For further details see:
 639             http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf
 640
 641 config TCP_CONG_CDG
 642         tristate "CAIA Delay-Gradient (CDG)"
 643         default n
 644         help
 645           CAIA Delay-Gradient (CDG) is a TCP congestion control that modifies
 646           the TCP sender in order to:
 647
 648           o Use the delay gradient as a congestion signal.
 649           o Back off with an average probability that is independent of the RTT.
 650           o Coexist with flows that use loss-based congestion control.
 651           o Tolerate packet loss unrelated to congestion.
 652
 653           For further details see:
 654             D.A. Hayes and G. Armitage. "Revisiting TCP congestion control using
 655             delay gradients." In Networking 2011. Preprint: http://goo.gl/No3vdg
 656
 657 config TCP_CONG_BBR
 658         tristate "BBR TCP"
 659         default n
 660         help
 661
 662           BBR (Bottleneck Bandwidth and RTT) TCP congestion control aims to
 663           maximize network utilization and minimize queues. It builds an explicit
 664           model of the bottleneck delivery rate and path round-trip propagation
 665           delay. It tolerates packet loss and delay unrelated to congestion. It
 666           can operate over LAN, WAN, cellular, wifi, or cable modem links. It can
 667           coexist with flows that use loss-based congestion control, and can
 668           operate with shallow buffers, deep buffers, bufferbloat, policers, or
 669           AQM schemes that do not provide a delay signal. It requires the fq
 670           ("Fair Queue") pacing packet scheduler.
 671
 672 choice
 673         prompt "Default TCP congestion control"
 674         default DEFAULT_CUBIC
 675         help
 676           Select the TCP congestion control that will be used by default
 677           for all connections.
 678
 679         config DEFAULT_BIC
 680                 bool "Bic" if TCP_CONG_BIC=y
 681
 682         config DEFAULT_CUBIC
 683                 bool "Cubic" if TCP_CONG_CUBIC=y
 684
 685         config DEFAULT_HTCP
 686                 bool "Htcp" if TCP_CONG_HTCP=y
 687
 688         config DEFAULT_HYBLA
 689                 bool "Hybla" if TCP_CONG_HYBLA=y
 690
 691         config DEFAULT_VEGAS
 692                 bool "Vegas" if TCP_CONG_VEGAS=y
 693
 694         config DEFAULT_VENO
 695                 bool "Veno" if TCP_CONG_VENO=y
 696
 697         config DEFAULT_WESTWOOD
 698                 bool "Westwood" if TCP_CONG_WESTWOOD=y
 699
 700         config DEFAULT_DCTCP
 701                 bool "DCTCP" if TCP_CONG_DCTCP=y
 702
 703         config DEFAULT_CDG
 704                 bool "CDG" if TCP_CONG_CDG=y
 705
 706         config DEFAULT_BBR
 707                 bool "BBR" if TCP_CONG_BBR=y
 708
 709         config DEFAULT_RENO
 710                 bool "Reno"
 711 endchoice
 712
 713 endif
 714
 715 config TCP_CONG_CUBIC
 716         tristate
 717         depends on !TCP_CONG_ADVANCED
 718         default y
 719
 720 config DEFAULT_TCP_CONG
 721         string
 722         default "bic" if DEFAULT_BIC
 723         default "cubic" if DEFAULT_CUBIC
 724         default "htcp" if DEFAULT_HTCP
 725         default "hybla" if DEFAULT_HYBLA
 726         default "vegas" if DEFAULT_VEGAS
 727         default "westwood" if DEFAULT_WESTWOOD
 728         default "veno" if DEFAULT_VENO
 729         default "reno" if DEFAULT_RENO
 730         default "dctcp" if DEFAULT_DCTCP
 731         default "cdg" if DEFAULT_CDG
 732         default "bbr" if DEFAULT_BBR
 733         default "cubic"
 734
 735 config TCP_MD5SIG
 736         bool "TCP: MD5 Signature Option support (RFC2385)"
 737         select CRYPTO
 738         select CRYPTO_MD5
 739         help
 740           RFC2385 specifies a method of giving MD5 protection to TCP sessions.
 741           Its main (only?) use is to protect BGP sessions between core routers
 742           on the Internet.
 743
 744           If unsure, say N.