1# SPDX-License-Identifier: GPL-2.0-only 2# 3# Network configuration 4# 5 6menuconfig 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 27if NET 28 29config WANT_COMPAT_NETLINK_MESSAGES 30 bool 31 help 32 This option can be selected by other options that need compat 33 netlink messages. 34 35config 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 49config NET_INGRESS 50 bool 51 52config NET_EGRESS 53 bool 54 55config NET_XGRESS 56 select NET_INGRESS 57 select NET_EGRESS 58 bool 59 60config NET_REDIRECT 61 bool 62 63config SKB_DECRYPTED 64 bool 65 66config SKB_EXTENSIONS 67 bool 68 69config NET_DEVMEM 70 def_bool y 71 depends on DMA_SHARED_BUFFER 72 depends on GENERIC_ALLOCATOR 73 depends on PAGE_POOL 74 75menu "Networking options" 76 77source "net/packet/Kconfig" 78source "net/unix/Kconfig" 79source "net/tls/Kconfig" 80source "net/xfrm/Kconfig" 81source "net/iucv/Kconfig" 82source "net/smc/Kconfig" 83source "net/xdp/Kconfig" 84 85config NET_HANDSHAKE 86 bool 87 depends on SUNRPC || NVME_TARGET_TCP || NVME_TCP 88 default y 89 90config NET_HANDSHAKE_KUNIT_TEST 91 tristate "KUnit tests for the handshake upcall mechanism" if !KUNIT_ALL_TESTS 92 default KUNIT_ALL_TESTS 93 depends on KUNIT 94 help 95 This builds the KUnit tests for the handshake upcall mechanism. 96 97 KUnit tests run during boot and output the results to the debug 98 log in TAP format (https://testanything.org/). Only useful for 99 kernel devs running KUnit test harness and are not for inclusion 100 into a production build. 101 102 For more information on KUnit and unit tests in general, refer 103 to the KUnit documentation in Documentation/dev-tools/kunit/. 104 105config INET 106 bool "TCP/IP networking" 107 help 108 These are the protocols used on the Internet and on most local 109 Ethernets. It is highly recommended to say Y here (this will enlarge 110 your kernel by about 400 KB), since some programs (e.g. the X window 111 system) use TCP/IP even if your machine is not connected to any 112 other computer. You will get the so-called loopback device which 113 allows you to ping yourself (great fun, that!). 114 115 For an excellent introduction to Linux networking, please read the 116 Linux Networking HOWTO, available from 117 <http://www.tldp.org/docs.html#howto>. 118 119 If you say Y here and also to "/proc file system support" and 120 "Sysctl support" below, you can change various aspects of the 121 behavior of the TCP/IP code by writing to the (virtual) files in 122 /proc/sys/net/ipv4/*; the options are explained in the file 123 <file:Documentation/networking/ip-sysctl.rst>. 124 125 Short answer: say Y. 126 127if INET 128source "net/ipv4/Kconfig" 129source "net/ipv6/Kconfig" 130source "net/netlabel/Kconfig" 131source "net/mptcp/Kconfig" 132 133endif # if INET 134 135config NETWORK_SECMARK 136 bool "Security Marking" 137 help 138 This enables security marking of network packets, similar 139 to nfmark, but designated for security purposes. 140 If you are unsure how to answer this question, answer N. 141 142config NET_PTP_CLASSIFY 143 def_bool n 144 145config NETWORK_PHY_TIMESTAMPING 146 bool "Timestamping in PHY devices" 147 select NET_PTP_CLASSIFY 148 help 149 This allows timestamping of network packets by PHYs (or 150 other MII bus snooping devices) with hardware timestamping 151 capabilities. This option adds some overhead in the transmit 152 and receive paths. 153 154 If you are unsure how to answer this question, answer N. 155 156menuconfig NETFILTER 157 bool "Network packet filtering framework (Netfilter)" 158 help 159 Netfilter is a framework for filtering and mangling network packets 160 that pass through your Linux box. 161 162 The most common use of packet filtering is to run your Linux box as 163 a firewall protecting a local network from the Internet. The type of 164 firewall provided by this kernel support is called a "packet 165 filter", which means that it can reject individual network packets 166 based on type, source, destination etc. The other kind of firewall, 167 a "proxy-based" one, is more secure but more intrusive and more 168 bothersome to set up; it inspects the network traffic much more 169 closely, modifies it and has knowledge about the higher level 170 protocols, which a packet filter lacks. Moreover, proxy-based 171 firewalls often require changes to the programs running on the local 172 clients. Proxy-based firewalls don't need support by the kernel, but 173 they are often combined with a packet filter, which only works if 174 you say Y here. 175 176 You should also say Y here if you intend to use your Linux box as 177 the gateway to the Internet for a local network of machines without 178 globally valid IP addresses. This is called "masquerading": if one 179 of the computers on your local network wants to send something to 180 the outside, your box can "masquerade" as that computer, i.e. it 181 forwards the traffic to the intended outside destination, but 182 modifies the packets to make it look like they came from the 183 firewall box itself. It works both ways: if the outside host 184 replies, the Linux box will silently forward the traffic to the 185 correct local computer. This way, the computers on your local net 186 are completely invisible to the outside world, even though they can 187 reach the outside and can receive replies. It is even possible to 188 run globally visible servers from within a masqueraded local network 189 using a mechanism called portforwarding. Masquerading is also often 190 called NAT (Network Address Translation). 191 192 Another use of Netfilter is in transparent proxying: if a machine on 193 the local network tries to connect to an outside host, your Linux 194 box can transparently forward the traffic to a local server, 195 typically a caching proxy server. 196 197 Yet another use of Netfilter is building a bridging firewall. Using 198 a bridge with Network packet filtering enabled makes iptables "see" 199 the bridged traffic. For filtering on the lower network and Ethernet 200 protocols over the bridge, use ebtables (under bridge netfilter 201 configuration). 202 203 Various modules exist for netfilter which replace the previous 204 masquerading (ipmasqadm), packet filtering (ipchains), transparent 205 proxying, and portforwarding mechanisms. Please see 206 <file:Documentation/Changes> under "iptables" for the location of 207 these packages. 208 209if NETFILTER 210 211config NETFILTER_ADVANCED 212 bool "Advanced netfilter configuration" 213 depends on NETFILTER 214 default y 215 help 216 If you say Y here you can select between all the netfilter modules. 217 If you say N the more unusual ones will not be shown and the 218 basic ones needed by most people will default to 'M'. 219 220 If unsure, say Y. 221 222config BRIDGE_NETFILTER 223 tristate "Bridged IP/ARP packets filtering" 224 depends on BRIDGE 225 depends on NETFILTER && INET 226 depends on NETFILTER_ADVANCED 227 select NETFILTER_FAMILY_BRIDGE 228 select SKB_EXTENSIONS 229 help 230 Enabling this option will let arptables resp. iptables see bridged 231 ARP resp. IP traffic. If you want a bridging firewall, you probably 232 want this option enabled. 233 Enabling or disabling this option doesn't enable or disable 234 ebtables. 235 236 If unsure, say N. 237 238source "net/netfilter/Kconfig" 239source "net/ipv4/netfilter/Kconfig" 240source "net/ipv6/netfilter/Kconfig" 241source "net/bridge/netfilter/Kconfig" 242 243endif 244 245source "net/dccp/Kconfig" 246source "net/sctp/Kconfig" 247source "net/rds/Kconfig" 248source "net/tipc/Kconfig" 249source "net/atm/Kconfig" 250source "net/l2tp/Kconfig" 251source "net/802/Kconfig" 252source "net/bridge/Kconfig" 253source "net/dsa/Kconfig" 254source "net/8021q/Kconfig" 255source "net/llc/Kconfig" 256source "net/appletalk/Kconfig" 257source "net/x25/Kconfig" 258source "net/lapb/Kconfig" 259source "net/phonet/Kconfig" 260source "net/6lowpan/Kconfig" 261source "net/ieee802154/Kconfig" 262source "net/mac802154/Kconfig" 263source "net/sched/Kconfig" 264source "net/dcb/Kconfig" 265source "net/dns_resolver/Kconfig" 266source "net/batman-adv/Kconfig" 267source "net/openvswitch/Kconfig" 268source "net/vmw_vsock/Kconfig" 269source "net/netlink/Kconfig" 270source "net/mpls/Kconfig" 271source "net/nsh/Kconfig" 272source "net/hsr/Kconfig" 273source "net/switchdev/Kconfig" 274source "net/l3mdev/Kconfig" 275source "net/qrtr/Kconfig" 276source "net/ncsi/Kconfig" 277 278config PCPU_DEV_REFCNT 279 bool "Use percpu variables to maintain network device refcount" 280 depends on SMP 281 default y 282 help 283 network device refcount are using per cpu variables if this option is set. 284 This can be forced to N to detect underflows (with a performance drop). 285 286config MAX_SKB_FRAGS 287 int "Maximum number of fragments per skb_shared_info" 288 range 17 45 289 default 17 290 help 291 Having more fragments per skb_shared_info can help GRO efficiency. 292 This helps BIG TCP workloads, but might expose bugs in some 293 legacy drivers. 294 This also increases memory overhead of small packets, 295 and in drivers using build_skb(). 296 If unsure, say 17. 297 298config RPS 299 bool "Receive packet steering" 300 depends on SMP && SYSFS 301 default y 302 help 303 Software receive side packet steering (RPS) distributes the 304 load of received packet processing across multiple CPUs. 305 306config RFS_ACCEL 307 bool "Hardware acceleration of RFS" 308 depends on RPS 309 select CPU_RMAP 310 default y 311 help 312 Allowing drivers for multiqueue hardware with flow filter tables to 313 accelerate RFS. 314 315config SOCK_RX_QUEUE_MAPPING 316 bool 317 318config XPS 319 bool 320 depends on SMP 321 select SOCK_RX_QUEUE_MAPPING 322 default y 323 324config HWBM 325 bool 326 327config CGROUP_NET_PRIO 328 bool "Network priority cgroup" 329 depends on CGROUPS 330 select SOCK_CGROUP_DATA 331 help 332 Cgroup subsystem for use in assigning processes to network priorities on 333 a per-interface basis. 334 335config CGROUP_NET_CLASSID 336 bool "Network classid cgroup" 337 depends on CGROUPS 338 select SOCK_CGROUP_DATA 339 help 340 Cgroup subsystem for use as general purpose socket classid marker that is 341 being used in cls_cgroup and for netfilter matching. 342 343config NET_RX_BUSY_POLL 344 bool 345 default y if !PREEMPT_RT || (PREEMPT_RT && !NETCONSOLE) 346 347config BQL 348 bool 349 prompt "Enable Byte Queue Limits" 350 depends on SYSFS 351 select DQL 352 default y 353 354config BPF_STREAM_PARSER 355 bool "enable BPF STREAM_PARSER" 356 depends on INET 357 depends on BPF_SYSCALL 358 depends on CGROUP_BPF 359 select STREAM_PARSER 360 select NET_SOCK_MSG 361 help 362 Enabling this allows a TCP stream parser to be used with 363 BPF_MAP_TYPE_SOCKMAP. 364 365config NET_FLOW_LIMIT 366 bool "Net flow limit" 367 depends on RPS 368 default y 369 help 370 The network stack has to drop packets when a receive processing CPU's 371 backlog reaches netdev_max_backlog. If a few out of many active flows 372 generate the vast majority of load, drop their traffic earlier to 373 maintain capacity for the other flows. This feature provides servers 374 with many clients some protection against DoS by a single (spoofed) 375 flow that greatly exceeds average workload. 376 377menu "Network testing" 378 379config NET_PKTGEN 380 tristate "Packet Generator (USE WITH CAUTION)" 381 depends on INET && PROC_FS 382 help 383 This module will inject preconfigured packets, at a configurable 384 rate, out of a given interface. It is used for network interface 385 stress testing and performance analysis. If you don't understand 386 what was just said, you don't need it: say N. 387 388 Documentation on how to use the packet generator can be found 389 at <file:Documentation/networking/pktgen.rst>. 390 391 To compile this code as a module, choose M here: the 392 module will be called pktgen. 393 394config NET_DROP_MONITOR 395 tristate "Network packet drop alerting service" 396 depends on INET && TRACEPOINTS 397 help 398 This feature provides an alerting service to userspace in the 399 event that packets are discarded in the network stack. Alerts 400 are broadcast via netlink socket to any listening user space 401 process. If you don't need network drop alerts, or if you are ok 402 just checking the various proc files and other utilities for 403 drop statistics, say N here. 404 405endmenu 406 407endmenu 408 409source "net/ax25/Kconfig" 410source "net/can/Kconfig" 411source "net/bluetooth/Kconfig" 412source "net/rxrpc/Kconfig" 413source "net/kcm/Kconfig" 414source "net/strparser/Kconfig" 415source "net/mctp/Kconfig" 416 417config FIB_RULES 418 bool 419 420menuconfig WIRELESS 421 bool "Wireless" 422 depends on !S390 423 default y 424 425if WIRELESS 426 427source "net/wireless/Kconfig" 428source "net/mac80211/Kconfig" 429 430endif # WIRELESS 431 432source "net/rfkill/Kconfig" 433source "net/9p/Kconfig" 434source "net/caif/Kconfig" 435source "net/ceph/Kconfig" 436source "net/nfc/Kconfig" 437source "net/psample/Kconfig" 438source "net/ife/Kconfig" 439 440config LWTUNNEL 441 bool "Network light weight tunnels" 442 help 443 This feature provides an infrastructure to support light weight 444 tunnels like mpls. There is no netdevice associated with a light 445 weight tunnel endpoint. Tunnel encapsulation parameters are stored 446 with light weight tunnel state associated with fib routes. 447 448config LWTUNNEL_BPF 449 bool "Execute BPF program as route nexthop action" 450 depends on LWTUNNEL && INET 451 default y if LWTUNNEL=y 452 help 453 Allows to run BPF programs as a nexthop action following a route 454 lookup for incoming and outgoing packets. 455 456config DST_CACHE 457 bool 458 default n 459 460config GRO_CELLS 461 bool 462 default n 463 464config SOCK_VALIDATE_XMIT 465 bool 466 467config NET_IEEE8021Q_HELPERS 468 bool 469 470config NET_SELFTESTS 471 def_tristate PHYLIB 472 depends on PHYLIB && INET 473 474config NET_SOCK_MSG 475 bool 476 default n 477 help 478 The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or 479 ULPs (upper layer modules, e.g. TLS) to process L7 application data 480 with the help of BPF programs. 481 482config NET_DEVLINK 483 bool 484 default n 485 486config PAGE_POOL 487 bool 488 489config PAGE_POOL_STATS 490 default n 491 bool "Page pool stats" 492 depends on PAGE_POOL 493 help 494 Enable page pool statistics to track page allocation and recycling 495 in page pools. This option incurs additional CPU cost in allocation 496 and recycle paths and additional memory cost to store the statistics. 497 These statistics are only available if this option is enabled and if 498 the driver using the page pool supports exporting this data. 499 500 If unsure, say N. 501 502config FAILOVER 503 tristate "Generic failover module" 504 help 505 The failover module provides a generic interface for paravirtual 506 drivers to register a netdev and a set of ops with a failover 507 instance. The ops are used as event handlers that get called to 508 handle netdev register/unregister/link change/name change events 509 on slave pci ethernet devices with the same mac address as the 510 failover netdev. This enables paravirtual drivers to use a 511 VF as an accelerated low latency datapath. It also allows live 512 migration of VMs with direct attached VFs by failing over to the 513 paravirtual datapath when the VF is unplugged. 514 515config ETHTOOL_NETLINK 516 bool "Netlink interface for ethtool" 517 select DIMLIB 518 default y 519 help 520 An alternative userspace interface for ethtool based on generic 521 netlink. It provides better extensibility and some new features, 522 e.g. notification messages. 523 524config NETDEV_ADDR_LIST_TEST 525 tristate "Unit tests for device address list" 526 default KUNIT_ALL_TESTS 527 depends on KUNIT 528 529config NET_TEST 530 tristate "KUnit tests for networking" if !KUNIT_ALL_TESTS 531 depends on KUNIT 532 default KUNIT_ALL_TESTS 533 help 534 KUnit tests covering core networking infra, such as sk_buff. 535 536 If unsure, say N. 537 538endif # if NET 539