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