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