net/Kconfig

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 #
   3 # Network configuration
   4 #
   5
   6 menuconfig NET
   7         bool "Networking support"
   8         select NLATTR
   9         select GENERIC_NET_UTILS
  10         select BPF
  11         help
  12           Unless you really know what you are doing, you should say Y here.
  13           The reason is that some programs need kernel networking support even
  14           when running on a stand-alone machine that isn't connected to any
  15           other computer.
  16
  17           If you are upgrading from an older kernel, you
  18           should consider updating your networking tools too because changes
  19           in the kernel and the tools often go hand in hand. The tools are
  20           contained in the package net-tools, the location and version number
  21           of which are given in <file:Documentation/Changes>.
  22
  23           For a general introduction to Linux networking, it is highly
  24           recommended to read the NET-HOWTO, available from
  25           <http://www.tldp.org/docs.html#howto>.
  26
  27 if NET
  28
  29 config WANT_COMPAT_NETLINK_MESSAGES
  30         bool
  31         help
  32           This option can be selected by other options that need compat
  33           netlink messages.
  34
  35 config COMPAT_NETLINK_MESSAGES
  36         def_bool y
  37         depends on COMPAT
  38         depends on WEXT_CORE || WANT_COMPAT_NETLINK_MESSAGES
  39         help
  40           This option makes it possible to send different netlink messages
  41           to tasks depending on whether the task is a compat task or not. To
  42           achieve this, you need to set skb_shinfo(skb)->frag_list to the
  43           compat skb before sending the skb, the netlink code will sort out
  44           which message to actually pass to the task.
  45
  46           Newly written code should NEVER need this option but do
  47           compat-independent messages instead!
  48
  49 config NET_INGRESS
  50         bool
  51
  52 config NET_EGRESS
  53         bool
  54
  55 config NET_XGRESS
  56         select NET_INGRESS
  57         select NET_EGRESS
  58         bool
  59
  60 config NET_REDIRECT
  61         bool
  62
  63 config SKB_DECRYPTED
  64         bool
  65
  66 config SKB_EXTENSIONS
  67         bool
  68
  69 menu "Networking options"
  70
  71 source "net/packet/Kconfig"
  72 source "net/unix/Kconfig"
  73 source "net/tls/Kconfig"
  74 source "net/xfrm/Kconfig"
  75 source "net/iucv/Kconfig"
  76 source "net/smc/Kconfig"
  77 source "net/xdp/Kconfig"
  78
  79 config NET_HANDSHAKE
  80         bool
  81         depends on SUNRPC || NVME_TARGET_TCP || NVME_TCP
  82         default y
  83
  84 config NET_HANDSHAKE_KUNIT_TEST
  85         tristate "KUnit tests for the handshake upcall mechanism" if !KUNIT_ALL_TESTS
  86         default KUNIT_ALL_TESTS
  87         depends on KUNIT
  88         help
  89           This builds the KUnit tests for the handshake upcall mechanism.
  90
  91           KUnit tests run during boot and output the results to the debug
  92           log in TAP format (https://testanything.org/). Only useful for
  93           kernel devs running KUnit test harness and are not for inclusion
  94           into a production build.
  95
  96           For more information on KUnit and unit tests in general, refer
  97           to the KUnit documentation in Documentation/dev-tools/kunit/.
  98
  99 config INET
 100         bool "TCP/IP networking"
 101         help
 102           These are the protocols used on the Internet and on most local
 103           Ethernets. It is highly recommended to say Y here (this will enlarge
 104           your kernel by about 400 KB), since some programs (e.g. the X window
 105           system) use TCP/IP even if your machine is not connected to any
 106           other computer. You will get the so-called loopback device which
 107           allows you to ping yourself (great fun, that!).
 108
 109           For an excellent introduction to Linux networking, please read the
 110           Linux Networking HOWTO, available from
 111           <http://www.tldp.org/docs.html#howto>.
 112
 113           If you say Y here and also to "/proc file system support" and
 114           "Sysctl support" below, you can change various aspects of the
 115           behavior of the TCP/IP code by writing to the (virtual) files in
 116           /proc/sys/net/ipv4/*; the options are explained in the file
 117           <file:Documentation/networking/ip-sysctl.rst>.
 118
 119           Short answer: say Y.
 120
 121 if INET
 122 source "net/ipv4/Kconfig"
 123 source "net/ipv6/Kconfig"
 124 source "net/netlabel/Kconfig"
 125 source "net/mptcp/Kconfig"
 126
 127 endif # if INET
 128
 129 config NETWORK_SECMARK
 130         bool "Security Marking"
 131         help
 132           This enables security marking of network packets, similar
 133           to nfmark, but designated for security purposes.
 134           If you are unsure how to answer this question, answer N.
 135
 136 config NET_PTP_CLASSIFY
 137         def_bool n
 138
 139 config NETWORK_PHY_TIMESTAMPING
 140         bool "Timestamping in PHY devices"
 141         select NET_PTP_CLASSIFY
 142         help
 143           This allows timestamping of network packets by PHYs (or
 144           other MII bus snooping devices) with hardware timestamping
 145           capabilities. This option adds some overhead in the transmit
 146           and receive paths.
 147
 148           If you are unsure how to answer this question, answer N.
 149
 150 menuconfig NETFILTER
 151         bool "Network packet filtering framework (Netfilter)"
 152         help
 153           Netfilter is a framework for filtering and mangling network packets
 154           that pass through your Linux box.
 155
 156           The most common use of packet filtering is to run your Linux box as
 157           a firewall protecting a local network from the Internet. The type of
 158           firewall provided by this kernel support is called a "packet
 159           filter", which means that it can reject individual network packets
 160           based on type, source, destination etc. The other kind of firewall,
 161           a "proxy-based" one, is more secure but more intrusive and more
 162           bothersome to set up; it inspects the network traffic much more
 163           closely, modifies it and has knowledge about the higher level
 164           protocols, which a packet filter lacks. Moreover, proxy-based
 165           firewalls often require changes to the programs running on the local
 166           clients. Proxy-based firewalls don't need support by the kernel, but
 167           they are often combined with a packet filter, which only works if
 168           you say Y here.
 169
 170           You should also say Y here if you intend to use your Linux box as
 171           the gateway to the Internet for a local network of machines without
 172           globally valid IP addresses. This is called "masquerading": if one
 173           of the computers on your local network wants to send something to
 174           the outside, your box can "masquerade" as that computer, i.e. it
 175           forwards the traffic to the intended outside destination, but
 176           modifies the packets to make it look like they came from the
 177           firewall box itself. It works both ways: if the outside host
 178           replies, the Linux box will silently forward the traffic to the
 179           correct local computer. This way, the computers on your local net
 180           are completely invisible to the outside world, even though they can
 181           reach the outside and can receive replies. It is even possible to
 182           run globally visible servers from within a masqueraded local network
 183           using a mechanism called portforwarding. Masquerading is also often
 184           called NAT (Network Address Translation).
 185
 186           Another use of Netfilter is in transparent proxying: if a machine on
 187           the local network tries to connect to an outside host, your Linux
 188           box can transparently forward the traffic to a local server,
 189           typically a caching proxy server.
 190
 191           Yet another use of Netfilter is building a bridging firewall. Using
 192           a bridge with Network packet filtering enabled makes iptables "see"
 193           the bridged traffic. For filtering on the lower network and Ethernet
 194           protocols over the bridge, use ebtables (under bridge netfilter
 195           configuration).
 196
 197           Various modules exist for netfilter which replace the previous
 198           masquerading (ipmasqadm), packet filtering (ipchains), transparent
 199           proxying, and portforwarding mechanisms. Please see
 200           <file:Documentation/Changes> under "iptables" for the location of
 201           these packages.
 202
 203 if NETFILTER
 204
 205 config NETFILTER_ADVANCED
 206         bool "Advanced netfilter configuration"
 207         depends on NETFILTER
 208         default y
 209         help
 210           If you say Y here you can select between all the netfilter modules.
 211           If you say N the more unusual ones will not be shown and the
 212           basic ones needed by most people will default to 'M'.
 213
 214           If unsure, say Y.
 215
 216 config BRIDGE_NETFILTER
 217         tristate "Bridged IP/ARP packets filtering"
 218         depends on BRIDGE
 219         depends on NETFILTER && INET
 220         depends on NETFILTER_ADVANCED
 221         select NETFILTER_FAMILY_BRIDGE
 222         select SKB_EXTENSIONS
 223         help
 224           Enabling this option will let arptables resp. iptables see bridged
 225           ARP resp. IP traffic. If you want a bridging firewall, you probably
 226           want this option enabled.
 227           Enabling or disabling this option doesn't enable or disable
 228           ebtables.
 229
 230           If unsure, say N.
 231
 232 source "net/netfilter/Kconfig"
 233 source "net/ipv4/netfilter/Kconfig"
 234 source "net/ipv6/netfilter/Kconfig"
 235 source "net/bridge/netfilter/Kconfig"
 236
 237 endif
 238
 239 source "net/dccp/Kconfig"
 240 source "net/sctp/Kconfig"
 241 source "net/rds/Kconfig"
 242 source "net/tipc/Kconfig"
 243 source "net/atm/Kconfig"
 244 source "net/l2tp/Kconfig"
 245 source "net/802/Kconfig"
 246 source "net/bridge/Kconfig"
 247 source "net/dsa/Kconfig"
 248 source "net/8021q/Kconfig"
 249 source "net/llc/Kconfig"
 250 source "net/appletalk/Kconfig"
 251 source "net/x25/Kconfig"
 252 source "net/lapb/Kconfig"
 253 source "net/phonet/Kconfig"
 254 source "net/6lowpan/Kconfig"
 255 source "net/ieee802154/Kconfig"
 256 source "net/mac802154/Kconfig"
 257 source "net/sched/Kconfig"
 258 source "net/dcb/Kconfig"
 259 source "net/dns_resolver/Kconfig"
 260 source "net/batman-adv/Kconfig"
 261 source "net/openvswitch/Kconfig"
 262 source "net/vmw_vsock/Kconfig"
 263 source "net/netlink/Kconfig"
 264 source "net/mpls/Kconfig"
 265 source "net/nsh/Kconfig"
 266 source "net/hsr/Kconfig"
 267 source "net/switchdev/Kconfig"
 268 source "net/l3mdev/Kconfig"
 269 source "net/qrtr/Kconfig"
 270 source "net/ncsi/Kconfig"
 271
 272 config PCPU_DEV_REFCNT
 273         bool "Use percpu variables to maintain network device refcount"
 274         depends on SMP
 275         default y
 276         help
 277           network device refcount are using per cpu variables if this option is set.
 278           This can be forced to N to detect underflows (with a performance drop).
 279
 280 config MAX_SKB_FRAGS
 281         int "Maximum number of fragments per skb_shared_info"
 282         range 17 45
 283         default 17
 284         help
 285           Having more fragments per skb_shared_info can help GRO efficiency.
 286           This helps BIG TCP workloads, but might expose bugs in some
 287           legacy drivers.
 288           This also increases memory overhead of small packets,
 289           and in drivers using build_skb().
 290           If unsure, say 17.
 291
 292 config RPS
 293         bool
 294         depends on SMP && SYSFS
 295         default y
 296
 297 config RFS_ACCEL
 298         bool
 299         depends on RPS
 300         select CPU_RMAP
 301         default y
 302
 303 config SOCK_RX_QUEUE_MAPPING
 304         bool
 305
 306 config XPS
 307         bool
 308         depends on SMP
 309         select SOCK_RX_QUEUE_MAPPING
 310         default y
 311
 312 config HWBM
 313         bool
 314
 315 config CGROUP_NET_PRIO
 316         bool "Network priority cgroup"
 317         depends on CGROUPS
 318         select SOCK_CGROUP_DATA
 319         help
 320           Cgroup subsystem for use in assigning processes to network priorities on
 321           a per-interface basis.
 322
 323 config CGROUP_NET_CLASSID
 324         bool "Network classid cgroup"
 325         depends on CGROUPS
 326         select SOCK_CGROUP_DATA
 327         help
 328           Cgroup subsystem for use as general purpose socket classid marker that is
 329           being used in cls_cgroup and for netfilter matching.
 330
 331 config NET_RX_BUSY_POLL
 332         bool
 333         default y if !PREEMPT_RT || (PREEMPT_RT && !NETCONSOLE)
 334
 335 config BQL
 336         bool
 337         prompt "Enable Byte Queue Limits"
 338         depends on SYSFS
 339         select DQL
 340         default y
 341
 342 config BPF_STREAM_PARSER
 343         bool "enable BPF STREAM_PARSER"
 344         depends on INET
 345         depends on BPF_SYSCALL
 346         depends on CGROUP_BPF
 347         select STREAM_PARSER
 348         select NET_SOCK_MSG
 349         help
 350           Enabling this allows a TCP stream parser to be used with
 351           BPF_MAP_TYPE_SOCKMAP.
 352
 353 config NET_FLOW_LIMIT
 354         bool
 355         depends on RPS
 356         default y
 357         help
 358           The network stack has to drop packets when a receive processing CPU's
 359           backlog reaches netdev_max_backlog. If a few out of many active flows
 360           generate the vast majority of load, drop their traffic earlier to
 361           maintain capacity for the other flows. This feature provides servers
 362           with many clients some protection against DoS by a single (spoofed)
 363           flow that greatly exceeds average workload.
 364
 365 menu "Network testing"
 366
 367 config NET_PKTGEN
 368         tristate "Packet Generator (USE WITH CAUTION)"
 369         depends on INET && PROC_FS
 370         help
 371           This module will inject preconfigured packets, at a configurable
 372           rate, out of a given interface.  It is used for network interface
 373           stress testing and performance analysis.  If you don't understand
 374           what was just said, you don't need it: say N.
 375
 376           Documentation on how to use the packet generator can be found
 377           at <file:Documentation/networking/pktgen.rst>.
 378
 379           To compile this code as a module, choose M here: the
 380           module will be called pktgen.
 381
 382 config NET_DROP_MONITOR
 383         tristate "Network packet drop alerting service"
 384         depends on INET && TRACEPOINTS
 385         help
 386           This feature provides an alerting service to userspace in the
 387           event that packets are discarded in the network stack.  Alerts
 388           are broadcast via netlink socket to any listening user space
 389           process.  If you don't need network drop alerts, or if you are ok
 390           just checking the various proc files and other utilities for
 391           drop statistics, say N here.
 392
 393 endmenu
 394
 395 endmenu
 396
 397 source "net/ax25/Kconfig"
 398 source "net/can/Kconfig"
 399 source "net/bluetooth/Kconfig"
 400 source "net/rxrpc/Kconfig"
 401 source "net/kcm/Kconfig"
 402 source "net/strparser/Kconfig"
 403 source "net/mctp/Kconfig"
 404
 405 config FIB_RULES
 406         bool
 407
 408 menuconfig WIRELESS
 409         bool "Wireless"
 410         depends on !S390
 411         default y
 412
 413 if WIRELESS
 414
 415 source "net/wireless/Kconfig"
 416 source "net/mac80211/Kconfig"
 417
 418 endif # WIRELESS
 419
 420 source "net/rfkill/Kconfig"
 421 source "net/9p/Kconfig"
 422 source "net/caif/Kconfig"
 423 source "net/ceph/Kconfig"
 424 source "net/nfc/Kconfig"
 425 source "net/psample/Kconfig"
 426 source "net/ife/Kconfig"
 427
 428 config LWTUNNEL
 429         bool "Network light weight tunnels"
 430         help
 431           This feature provides an infrastructure to support light weight
 432           tunnels like mpls. There is no netdevice associated with a light
 433           weight tunnel endpoint. Tunnel encapsulation parameters are stored
 434           with light weight tunnel state associated with fib routes.
 435
 436 config LWTUNNEL_BPF
 437         bool "Execute BPF program as route nexthop action"
 438         depends on LWTUNNEL && INET
 439         default y if LWTUNNEL=y
 440         help
 441           Allows to run BPF programs as a nexthop action following a route
 442           lookup for incoming and outgoing packets.
 443
 444 config DST_CACHE
 445         bool
 446         default n
 447
 448 config GRO_CELLS
 449         bool
 450         default n
 451
 452 config SOCK_VALIDATE_XMIT
 453         bool
 454
 455 config NET_IEEE8021Q_HELPERS
 456         bool
 457
 458 config NET_SELFTESTS
 459         def_tristate PHYLIB
 460         depends on PHYLIB && INET
 461
 462 config NET_SOCK_MSG
 463         bool
 464         default n
 465         help
 466           The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or
 467           ULPs (upper layer modules, e.g. TLS) to process L7 application data
 468           with the help of BPF programs.
 469
 470 config NET_DEVLINK
 471         bool
 472         default n
 473
 474 config PAGE_POOL
 475         bool
 476
 477 config PAGE_POOL_STATS
 478         default n
 479         bool "Page pool stats"
 480         depends on PAGE_POOL
 481         help
 482           Enable page pool statistics to track page allocation and recycling
 483           in page pools. This option incurs additional CPU cost in allocation
 484           and recycle paths and additional memory cost to store the statistics.
 485           These statistics are only available if this option is enabled and if
 486           the driver using the page pool supports exporting this data.
 487
 488           If unsure, say N.
 489
 490 config FAILOVER
 491         tristate "Generic failover module"
 492         help
 493           The failover module provides a generic interface for paravirtual
 494           drivers to register a netdev and a set of ops with a failover
 495           instance. The ops are used as event handlers that get called to
 496           handle netdev register/unregister/link change/name change events
 497           on slave pci ethernet devices with the same mac address as the
 498           failover netdev. This enables paravirtual drivers to use a
 499           VF as an accelerated low latency datapath. It also allows live
 500           migration of VMs with direct attached VFs by failing over to the
 501           paravirtual datapath when the VF is unplugged.
 502
 503 config ETHTOOL_NETLINK
 504         bool "Netlink interface for ethtool"
 505         default y
 506         help
 507           An alternative userspace interface for ethtool based on generic
 508           netlink. It provides better extensibility and some new features,
 509           e.g. notification messages.
 510
 511 config NETDEV_ADDR_LIST_TEST
 512         tristate "Unit tests for device address list"
 513         default KUNIT_ALL_TESTS
 514         depends on KUNIT
 515
 516 config NET_TEST
 517         tristate "KUnit tests for networking" if !KUNIT_ALL_TESTS
 518         depends on KUNIT
 519         default KUNIT_ALL_TESTS
 520         help
 521           KUnit tests covering core networking infra, such as sk_buff.
 522
 523           If unsure, say N.
 524
 525 endif   # if NET