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 75config NET_SHAPER 76 bool 77 78menu "Networking options" 79 80source "net/packet/Kconfig" 81source "net/unix/Kconfig" 82source "net/tls/Kconfig" 83source "net/xfrm/Kconfig" 84source "net/iucv/Kconfig" 85source "net/smc/Kconfig" 86source "net/xdp/Kconfig" 87 88config NET_HANDSHAKE 89 bool 90 depends on SUNRPC || NVME_TARGET_TCP || NVME_TCP 91 default y 92 93config NET_HANDSHAKE_KUNIT_TEST 94 tristate "KUnit tests for the handshake upcall mechanism" if !KUNIT_ALL_TESTS 95 default KUNIT_ALL_TESTS 96 depends on KUNIT 97 help 98 This builds the KUnit tests for the handshake upcall mechanism. 99 100 KUnit tests run during boot and output the results to the debug 101 log in TAP format (https://testanything.org/). Only useful for 102 kernel devs running KUnit test harness and are not for inclusion 103 into a production build. 104 105 For more information on KUnit and unit tests in general, refer 106 to the KUnit documentation in Documentation/dev-tools/kunit/. 107 108config INET 109 bool "TCP/IP networking" 110 help 111 These are the protocols used on the Internet and on most local 112 Ethernets. It is highly recommended to say Y here (this will enlarge 113 your kernel by about 400 KB), since some programs (e.g. the X window 114 system) use TCP/IP even if your machine is not connected to any 115 other computer. You will get the so-called loopback device which 116 allows you to ping yourself (great fun, that!). 117 118 For an excellent introduction to Linux networking, please read the 119 Linux Networking HOWTO, available from 120 <http://www.tldp.org/docs.html#howto>. 121 122 If you say Y here and also to "/proc file system support" and 123 "Sysctl support" below, you can change various aspects of the 124 behavior of the TCP/IP code by writing to the (virtual) files in 125 /proc/sys/net/ipv4/*; the options are explained in the file 126 <file:Documentation/networking/ip-sysctl.rst>. 127 128 Short answer: say Y. 129 130if INET 131source "net/ipv4/Kconfig" 132source "net/ipv6/Kconfig" 133source "net/netlabel/Kconfig" 134source "net/mptcp/Kconfig" 135 136endif # if INET 137 138config NETWORK_SECMARK 139 bool "Security Marking" 140 help 141 This enables security marking of network packets, similar 142 to nfmark, but designated for security purposes. 143 If you are unsure how to answer this question, answer N. 144 145config NET_PTP_CLASSIFY 146 def_bool n 147 148config NETWORK_PHY_TIMESTAMPING 149 bool "Timestamping in PHY devices" 150 select NET_PTP_CLASSIFY 151 help 152 This allows timestamping of network packets by PHYs (or 153 other MII bus snooping devices) with hardware timestamping 154 capabilities. This option adds some overhead in the transmit 155 and receive paths. 156 157 If you are unsure how to answer this question, answer N. 158 159menuconfig NETFILTER 160 bool "Network packet filtering framework (Netfilter)" 161 help 162 Netfilter is a framework for filtering and mangling network packets 163 that pass through your Linux box. 164 165 The most common use of packet filtering is to run your Linux box as 166 a firewall protecting a local network from the Internet. The type of 167 firewall provided by this kernel support is called a "packet 168 filter", which means that it can reject individual network packets 169 based on type, source, destination etc. The other kind of firewall, 170 a "proxy-based" one, is more secure but more intrusive and more 171 bothersome to set up; it inspects the network traffic much more 172 closely, modifies it and has knowledge about the higher level 173 protocols, which a packet filter lacks. Moreover, proxy-based 174 firewalls often require changes to the programs running on the local 175 clients. Proxy-based firewalls don't need support by the kernel, but 176 they are often combined with a packet filter, which only works if 177 you say Y here. 178 179 You should also say Y here if you intend to use your Linux box as 180 the gateway to the Internet for a local network of machines without 181 globally valid IP addresses. This is called "masquerading": if one 182 of the computers on your local network wants to send something to 183 the outside, your box can "masquerade" as that computer, i.e. it 184 forwards the traffic to the intended outside destination, but 185 modifies the packets to make it look like they came from the 186 firewall box itself. It works both ways: if the outside host 187 replies, the Linux box will silently forward the traffic to the 188 correct local computer. This way, the computers on your local net 189 are completely invisible to the outside world, even though they can 190 reach the outside and can receive replies. It is even possible to 191 run globally visible servers from within a masqueraded local network 192 using a mechanism called portforwarding. Masquerading is also often 193 called NAT (Network Address Translation). 194 195 Another use of Netfilter is in transparent proxying: if a machine on 196 the local network tries to connect to an outside host, your Linux 197 box can transparently forward the traffic to a local server, 198 typically a caching proxy server. 199 200 Yet another use of Netfilter is building a bridging firewall. Using 201 a bridge with Network packet filtering enabled makes iptables "see" 202 the bridged traffic. For filtering on the lower network and Ethernet 203 protocols over the bridge, use ebtables (under bridge netfilter 204 configuration). 205 206 Various modules exist for netfilter which replace the previous 207 masquerading (ipmasqadm), packet filtering (ipchains), transparent 208 proxying, and portforwarding mechanisms. Please see 209 <file:Documentation/Changes> under "iptables" for the location of 210 these packages. 211 212if NETFILTER 213 214config NETFILTER_ADVANCED 215 bool "Advanced netfilter configuration" 216 depends on NETFILTER 217 default y 218 help 219 If you say Y here you can select between all the netfilter modules. 220 If you say N the more unusual ones will not be shown and the 221 basic ones needed by most people will default to 'M'. 222 223 If unsure, say Y. 224 225config BRIDGE_NETFILTER 226 tristate "Bridged IP/ARP packets filtering" 227 depends on BRIDGE 228 depends on NETFILTER && INET 229 depends on NETFILTER_ADVANCED 230 select NETFILTER_FAMILY_BRIDGE 231 select SKB_EXTENSIONS 232 help 233 Enabling this option will let arptables resp. iptables see bridged 234 ARP resp. IP traffic. If you want a bridging firewall, you probably 235 want this option enabled. 236 Enabling or disabling this option doesn't enable or disable 237 ebtables. 238 239 If unsure, say N. 240 241source "net/netfilter/Kconfig" 242source "net/ipv4/netfilter/Kconfig" 243source "net/ipv6/netfilter/Kconfig" 244source "net/bridge/netfilter/Kconfig" 245 246endif 247 248source "net/sctp/Kconfig" 249source "net/rds/Kconfig" 250source "net/tipc/Kconfig" 251source "net/atm/Kconfig" 252source "net/l2tp/Kconfig" 253source "net/802/Kconfig" 254source "net/bridge/Kconfig" 255source "net/dsa/Kconfig" 256source "net/8021q/Kconfig" 257source "net/llc/Kconfig" 258source "net/appletalk/Kconfig" 259source "net/x25/Kconfig" 260source "net/lapb/Kconfig" 261source "net/phonet/Kconfig" 262source "net/6lowpan/Kconfig" 263source "net/ieee802154/Kconfig" 264source "net/mac802154/Kconfig" 265source "net/sched/Kconfig" 266source "net/dcb/Kconfig" 267source "net/dns_resolver/Kconfig" 268source "net/batman-adv/Kconfig" 269source "net/openvswitch/Kconfig" 270source "net/vmw_vsock/Kconfig" 271source "net/netlink/Kconfig" 272source "net/mpls/Kconfig" 273source "net/nsh/Kconfig" 274source "net/hsr/Kconfig" 275source "net/switchdev/Kconfig" 276source "net/l3mdev/Kconfig" 277source "net/qrtr/Kconfig" 278source "net/ncsi/Kconfig" 279 280config PCPU_DEV_REFCNT 281 bool "Use percpu variables to maintain network device refcount" 282 depends on SMP 283 default y 284 help 285 network device refcount are using per cpu variables if this option is set. 286 This can be forced to N to detect underflows (with a performance drop). 287 288config MAX_SKB_FRAGS 289 int "Maximum number of fragments per skb_shared_info" 290 range 17 45 291 default 17 292 help 293 Having more fragments per skb_shared_info can help GRO efficiency. 294 This helps BIG TCP workloads, but might expose bugs in some 295 legacy drivers. 296 This also increases memory overhead of small packets, 297 and in drivers using build_skb(). 298 If unsure, say 17. 299 300config RPS 301 bool "Receive packet steering" 302 depends on SMP && SYSFS 303 default y 304 help 305 Software receive side packet steering (RPS) distributes the 306 load of received packet processing across multiple CPUs. 307 308config RFS_ACCEL 309 bool "Hardware acceleration of RFS" 310 depends on RPS 311 select CPU_RMAP 312 default y 313 help 314 Allowing drivers for multiqueue hardware with flow filter tables to 315 accelerate RFS. 316 317config SOCK_RX_QUEUE_MAPPING 318 bool 319 320config XPS 321 bool 322 depends on SMP 323 select SOCK_RX_QUEUE_MAPPING 324 default y 325 326config HWBM 327 bool 328 329config CGROUP_NET_PRIO 330 bool "Network priority cgroup" 331 depends on CGROUPS 332 select SOCK_CGROUP_DATA 333 help 334 Cgroup subsystem for use in assigning processes to network priorities on 335 a per-interface basis. 336 337config CGROUP_NET_CLASSID 338 bool "Network classid cgroup" 339 depends on CGROUPS 340 select SOCK_CGROUP_DATA 341 help 342 Cgroup subsystem for use as general purpose socket classid marker that is 343 being used in cls_cgroup and for netfilter matching. 344 345config NET_RX_BUSY_POLL 346 bool 347 default y if !PREEMPT_RT || (PREEMPT_RT && !NETCONSOLE) 348 349config BQL 350 bool 351 prompt "Enable Byte Queue Limits" 352 depends on SYSFS 353 select DQL 354 default y 355 356config BPF_STREAM_PARSER 357 bool "enable BPF STREAM_PARSER" 358 depends on INET 359 depends on BPF_SYSCALL 360 depends on CGROUP_BPF 361 select STREAM_PARSER 362 select NET_SOCK_MSG 363 help 364 Enabling this allows a TCP stream parser to be used with 365 BPF_MAP_TYPE_SOCKMAP. 366 367config NET_FLOW_LIMIT 368 bool "Net flow limit" 369 depends on RPS 370 default y 371 help 372 The network stack has to drop packets when a receive processing CPU's 373 backlog reaches netdev_max_backlog. If a few out of many active flows 374 generate the vast majority of load, drop their traffic earlier to 375 maintain capacity for the other flows. This feature provides servers 376 with many clients some protection against DoS by a single (spoofed) 377 flow that greatly exceeds average workload. 378 379menu "Network testing" 380 381config NET_PKTGEN 382 tristate "Packet Generator (USE WITH CAUTION)" 383 depends on INET && PROC_FS 384 help 385 This module will inject preconfigured packets, at a configurable 386 rate, out of a given interface. It is used for network interface 387 stress testing and performance analysis. If you don't understand 388 what was just said, you don't need it: say N. 389 390 Documentation on how to use the packet generator can be found 391 at <file:Documentation/networking/pktgen.rst>. 392 393 To compile this code as a module, choose M here: the 394 module will be called pktgen. 395 396config NET_DROP_MONITOR 397 tristate "Network packet drop alerting service" 398 depends on INET && TRACEPOINTS 399 help 400 This feature provides an alerting service to userspace in the 401 event that packets are discarded in the network stack. Alerts 402 are broadcast via netlink socket to any listening user space 403 process. If you don't need network drop alerts, or if you are ok 404 just checking the various proc files and other utilities for 405 drop statistics, say N here. 406 407endmenu 408 409endmenu 410 411source "net/ax25/Kconfig" 412source "net/can/Kconfig" 413source "net/bluetooth/Kconfig" 414source "net/rxrpc/Kconfig" 415source "net/kcm/Kconfig" 416source "net/strparser/Kconfig" 417source "net/mctp/Kconfig" 418 419config FIB_RULES 420 bool 421 422menuconfig WIRELESS 423 bool "Wireless" 424 depends on !S390 425 default y 426 427if WIRELESS 428 429source "net/wireless/Kconfig" 430source "net/mac80211/Kconfig" 431 432endif # WIRELESS 433 434source "net/rfkill/Kconfig" 435source "net/9p/Kconfig" 436source "net/caif/Kconfig" 437source "net/ceph/Kconfig" 438source "net/nfc/Kconfig" 439source "net/psample/Kconfig" 440source "net/ife/Kconfig" 441 442config LWTUNNEL 443 bool "Network light weight tunnels" 444 help 445 This feature provides an infrastructure to support light weight 446 tunnels like mpls. There is no netdevice associated with a light 447 weight tunnel endpoint. Tunnel encapsulation parameters are stored 448 with light weight tunnel state associated with fib routes. 449 450config LWTUNNEL_BPF 451 bool "Execute BPF program as route nexthop action" 452 depends on LWTUNNEL && INET 453 default y if LWTUNNEL=y 454 help 455 Allows to run BPF programs as a nexthop action following a route 456 lookup for incoming and outgoing packets. 457 458config DST_CACHE 459 bool 460 default n 461 462config GRO_CELLS 463 bool 464 default n 465 466config SOCK_VALIDATE_XMIT 467 bool 468 469config NET_IEEE8021Q_HELPERS 470 bool 471 472config NET_SELFTESTS 473 def_tristate PHYLIB 474 depends on PHYLIB && INET 475 476config NET_SOCK_MSG 477 bool 478 default n 479 help 480 The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or 481 ULPs (upper layer modules, e.g. TLS) to process L7 application data 482 with the help of BPF programs. 483 484config NET_DEVLINK 485 bool 486 default n 487 488config PAGE_POOL 489 bool 490 491config PAGE_POOL_STATS 492 default n 493 bool "Page pool stats" 494 depends on PAGE_POOL 495 help 496 Enable page pool statistics to track page allocation and recycling 497 in page pools. This option incurs additional CPU cost in allocation 498 and recycle paths and additional memory cost to store the statistics. 499 These statistics are only available if this option is enabled and if 500 the driver using the page pool supports exporting this data. 501 502 If unsure, say N. 503 504config FAILOVER 505 tristate "Generic failover module" 506 help 507 The failover module provides a generic interface for paravirtual 508 drivers to register a netdev and a set of ops with a failover 509 instance. The ops are used as event handlers that get called to 510 handle netdev register/unregister/link change/name change events 511 on slave pci ethernet devices with the same mac address as the 512 failover netdev. This enables paravirtual drivers to use a 513 VF as an accelerated low latency datapath. It also allows live 514 migration of VMs with direct attached VFs by failing over to the 515 paravirtual datapath when the VF is unplugged. 516 517config ETHTOOL_NETLINK 518 bool "Netlink interface for ethtool" 519 select DIMLIB 520 default y 521 help 522 An alternative userspace interface for ethtool based on generic 523 netlink. It provides better extensibility and some new features, 524 e.g. notification messages. 525 526config NETDEV_ADDR_LIST_TEST 527 tristate "Unit tests for device address list" 528 default KUNIT_ALL_TESTS 529 depends on KUNIT 530 531config NET_TEST 532 tristate "KUnit tests for networking" if !KUNIT_ALL_TESTS 533 depends on KUNIT 534 default KUNIT_ALL_TESTS 535 help 536 KUnit tests covering core networking infra, such as sk_buff. 537 538 If unsure, say N. 539 540endif # if NET 541