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/dccp/Kconfig" 249source "net/sctp/Kconfig" 250source "net/rds/Kconfig" 251source "net/tipc/Kconfig" 252source "net/atm/Kconfig" 253source "net/l2tp/Kconfig" 254source "net/802/Kconfig" 255source "net/bridge/Kconfig" 256source "net/dsa/Kconfig" 257source "net/8021q/Kconfig" 258source "net/llc/Kconfig" 259source "net/appletalk/Kconfig" 260source "net/x25/Kconfig" 261source "net/lapb/Kconfig" 262source "net/phonet/Kconfig" 263source "net/6lowpan/Kconfig" 264source "net/ieee802154/Kconfig" 265source "net/mac802154/Kconfig" 266source "net/sched/Kconfig" 267source "net/dcb/Kconfig" 268source "net/dns_resolver/Kconfig" 269source "net/batman-adv/Kconfig" 270source "net/openvswitch/Kconfig" 271source "net/vmw_vsock/Kconfig" 272source "net/netlink/Kconfig" 273source "net/mpls/Kconfig" 274source "net/nsh/Kconfig" 275source "net/hsr/Kconfig" 276source "net/switchdev/Kconfig" 277source "net/l3mdev/Kconfig" 278source "net/qrtr/Kconfig" 279source "net/ncsi/Kconfig" 280 281config PCPU_DEV_REFCNT 282 bool "Use percpu variables to maintain network device refcount" 283 depends on SMP 284 default y 285 help 286 network device refcount are using per cpu variables if this option is set. 287 This can be forced to N to detect underflows (with a performance drop). 288 289config MAX_SKB_FRAGS 290 int "Maximum number of fragments per skb_shared_info" 291 range 17 45 292 default 17 293 help 294 Having more fragments per skb_shared_info can help GRO efficiency. 295 This helps BIG TCP workloads, but might expose bugs in some 296 legacy drivers. 297 This also increases memory overhead of small packets, 298 and in drivers using build_skb(). 299 If unsure, say 17. 300 301config RPS 302 bool "Receive packet steering" 303 depends on SMP && SYSFS 304 default y 305 help 306 Software receive side packet steering (RPS) distributes the 307 load of received packet processing across multiple CPUs. 308 309config RFS_ACCEL 310 bool "Hardware acceleration of RFS" 311 depends on RPS 312 select CPU_RMAP 313 default y 314 help 315 Allowing drivers for multiqueue hardware with flow filter tables to 316 accelerate RFS. 317 318config SOCK_RX_QUEUE_MAPPING 319 bool 320 321config XPS 322 bool 323 depends on SMP 324 select SOCK_RX_QUEUE_MAPPING 325 default y 326 327config HWBM 328 bool 329 330config CGROUP_NET_PRIO 331 bool "Network priority cgroup" 332 depends on CGROUPS 333 select SOCK_CGROUP_DATA 334 help 335 Cgroup subsystem for use in assigning processes to network priorities on 336 a per-interface basis. 337 338config CGROUP_NET_CLASSID 339 bool "Network classid cgroup" 340 depends on CGROUPS 341 select SOCK_CGROUP_DATA 342 help 343 Cgroup subsystem for use as general purpose socket classid marker that is 344 being used in cls_cgroup and for netfilter matching. 345 346config NET_RX_BUSY_POLL 347 bool 348 default y if !PREEMPT_RT || (PREEMPT_RT && !NETCONSOLE) 349 350config BQL 351 bool 352 prompt "Enable Byte Queue Limits" 353 depends on SYSFS 354 select DQL 355 default y 356 357config BPF_STREAM_PARSER 358 bool "enable BPF STREAM_PARSER" 359 depends on INET 360 depends on BPF_SYSCALL 361 depends on CGROUP_BPF 362 select STREAM_PARSER 363 select NET_SOCK_MSG 364 help 365 Enabling this allows a TCP stream parser to be used with 366 BPF_MAP_TYPE_SOCKMAP. 367 368config NET_FLOW_LIMIT 369 bool "Net flow limit" 370 depends on RPS 371 default y 372 help 373 The network stack has to drop packets when a receive processing CPU's 374 backlog reaches netdev_max_backlog. If a few out of many active flows 375 generate the vast majority of load, drop their traffic earlier to 376 maintain capacity for the other flows. This feature provides servers 377 with many clients some protection against DoS by a single (spoofed) 378 flow that greatly exceeds average workload. 379 380menu "Network testing" 381 382config NET_PKTGEN 383 tristate "Packet Generator (USE WITH CAUTION)" 384 depends on INET && PROC_FS 385 help 386 This module will inject preconfigured packets, at a configurable 387 rate, out of a given interface. It is used for network interface 388 stress testing and performance analysis. If you don't understand 389 what was just said, you don't need it: say N. 390 391 Documentation on how to use the packet generator can be found 392 at <file:Documentation/networking/pktgen.rst>. 393 394 To compile this code as a module, choose M here: the 395 module will be called pktgen. 396 397config NET_DROP_MONITOR 398 tristate "Network packet drop alerting service" 399 depends on INET && TRACEPOINTS 400 help 401 This feature provides an alerting service to userspace in the 402 event that packets are discarded in the network stack. Alerts 403 are broadcast via netlink socket to any listening user space 404 process. If you don't need network drop alerts, or if you are ok 405 just checking the various proc files and other utilities for 406 drop statistics, say N here. 407 408endmenu 409 410endmenu 411 412source "net/ax25/Kconfig" 413source "net/can/Kconfig" 414source "net/bluetooth/Kconfig" 415source "net/rxrpc/Kconfig" 416source "net/kcm/Kconfig" 417source "net/strparser/Kconfig" 418source "net/mctp/Kconfig" 419 420config FIB_RULES 421 bool 422 423menuconfig WIRELESS 424 bool "Wireless" 425 depends on !S390 426 default y 427 428if WIRELESS 429 430source "net/wireless/Kconfig" 431source "net/mac80211/Kconfig" 432 433endif # WIRELESS 434 435source "net/rfkill/Kconfig" 436source "net/9p/Kconfig" 437source "net/caif/Kconfig" 438source "net/ceph/Kconfig" 439source "net/nfc/Kconfig" 440source "net/psample/Kconfig" 441source "net/ife/Kconfig" 442 443config LWTUNNEL 444 bool "Network light weight tunnels" 445 help 446 This feature provides an infrastructure to support light weight 447 tunnels like mpls. There is no netdevice associated with a light 448 weight tunnel endpoint. Tunnel encapsulation parameters are stored 449 with light weight tunnel state associated with fib routes. 450 451config LWTUNNEL_BPF 452 bool "Execute BPF program as route nexthop action" 453 depends on LWTUNNEL && INET 454 default y if LWTUNNEL=y 455 help 456 Allows to run BPF programs as a nexthop action following a route 457 lookup for incoming and outgoing packets. 458 459config DST_CACHE 460 bool 461 default n 462 463config GRO_CELLS 464 bool 465 default n 466 467config SOCK_VALIDATE_XMIT 468 bool 469 470config NET_IEEE8021Q_HELPERS 471 bool 472 473config NET_SELFTESTS 474 def_tristate PHYLIB 475 depends on PHYLIB && INET 476 477config NET_SOCK_MSG 478 bool 479 default n 480 help 481 The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or 482 ULPs (upper layer modules, e.g. TLS) to process L7 application data 483 with the help of BPF programs. 484 485config NET_DEVLINK 486 bool 487 default n 488 489config PAGE_POOL 490 bool 491 492config PAGE_POOL_STATS 493 default n 494 bool "Page pool stats" 495 depends on PAGE_POOL 496 help 497 Enable page pool statistics to track page allocation and recycling 498 in page pools. This option incurs additional CPU cost in allocation 499 and recycle paths and additional memory cost to store the statistics. 500 These statistics are only available if this option is enabled and if 501 the driver using the page pool supports exporting this data. 502 503 If unsure, say N. 504 505config FAILOVER 506 tristate "Generic failover module" 507 help 508 The failover module provides a generic interface for paravirtual 509 drivers to register a netdev and a set of ops with a failover 510 instance. The ops are used as event handlers that get called to 511 handle netdev register/unregister/link change/name change events 512 on slave pci ethernet devices with the same mac address as the 513 failover netdev. This enables paravirtual drivers to use a 514 VF as an accelerated low latency datapath. It also allows live 515 migration of VMs with direct attached VFs by failing over to the 516 paravirtual datapath when the VF is unplugged. 517 518config ETHTOOL_NETLINK 519 bool "Netlink interface for ethtool" 520 select DIMLIB 521 default y 522 help 523 An alternative userspace interface for ethtool based on generic 524 netlink. It provides better extensibility and some new features, 525 e.g. notification messages. 526 527config NETDEV_ADDR_LIST_TEST 528 tristate "Unit tests for device address list" 529 default KUNIT_ALL_TESTS 530 depends on KUNIT 531 532config NET_TEST 533 tristate "KUnit tests for networking" if !KUNIT_ALL_TESTS 534 depends on KUNIT 535 default KUNIT_ALL_TESTS 536 help 537 KUnit tests covering core networking infra, such as sk_buff. 538 539 If unsure, say N. 540 541endif # if NET 542