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_EXTENSIONS 64 bool 65 66menu "Networking options" 67 68source "net/packet/Kconfig" 69source "net/unix/Kconfig" 70source "net/tls/Kconfig" 71source "net/xfrm/Kconfig" 72source "net/iucv/Kconfig" 73source "net/smc/Kconfig" 74source "net/xdp/Kconfig" 75 76config NET_HANDSHAKE 77 bool 78 depends on SUNRPC || NVME_TARGET_TCP || NVME_TCP 79 default y 80 81config 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 96config 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 118if INET 119source "net/ipv4/Kconfig" 120source "net/ipv6/Kconfig" 121source "net/netlabel/Kconfig" 122source "net/mptcp/Kconfig" 123 124endif # if INET 125 126config 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 133config NET_PTP_CLASSIFY 134 def_bool n 135 136config 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 147menuconfig 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 200if NETFILTER 201 202config 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 213config 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 229source "net/netfilter/Kconfig" 230source "net/ipv4/netfilter/Kconfig" 231source "net/ipv6/netfilter/Kconfig" 232source "net/bridge/netfilter/Kconfig" 233 234endif 235 236source "net/dccp/Kconfig" 237source "net/sctp/Kconfig" 238source "net/rds/Kconfig" 239source "net/tipc/Kconfig" 240source "net/atm/Kconfig" 241source "net/l2tp/Kconfig" 242source "net/802/Kconfig" 243source "net/bridge/Kconfig" 244source "net/dsa/Kconfig" 245source "net/8021q/Kconfig" 246source "net/llc/Kconfig" 247source "net/appletalk/Kconfig" 248source "net/x25/Kconfig" 249source "net/lapb/Kconfig" 250source "net/phonet/Kconfig" 251source "net/6lowpan/Kconfig" 252source "net/ieee802154/Kconfig" 253source "net/mac802154/Kconfig" 254source "net/sched/Kconfig" 255source "net/dcb/Kconfig" 256source "net/dns_resolver/Kconfig" 257source "net/batman-adv/Kconfig" 258source "net/openvswitch/Kconfig" 259source "net/vmw_vsock/Kconfig" 260source "net/netlink/Kconfig" 261source "net/mpls/Kconfig" 262source "net/nsh/Kconfig" 263source "net/hsr/Kconfig" 264source "net/switchdev/Kconfig" 265source "net/l3mdev/Kconfig" 266source "net/qrtr/Kconfig" 267source "net/ncsi/Kconfig" 268 269config 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 277config 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 289config RPS 290 bool 291 depends on SMP && SYSFS 292 default y 293 294config RFS_ACCEL 295 bool 296 depends on RPS 297 select CPU_RMAP 298 default y 299 300config SOCK_RX_QUEUE_MAPPING 301 bool 302 303config XPS 304 bool 305 depends on SMP 306 select SOCK_RX_QUEUE_MAPPING 307 default y 308 309config HWBM 310 bool 311 312config 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 320config 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 328config NET_RX_BUSY_POLL 329 bool 330 default y if !PREEMPT_RT || (PREEMPT_RT && !NETCONSOLE) 331 332config BQL 333 bool 334 prompt "Enable Byte Queue Limits" 335 depends on SYSFS 336 select DQL 337 default y 338 339config BPF_STREAM_PARSER 340 bool "enable BPF STREAM_PARSER" 341 depends on INET 342 depends on BPF_SYSCALL 343 depends on CGROUP_BPF 344 select STREAM_PARSER 345 select NET_SOCK_MSG 346 help 347 Enabling this allows a TCP stream parser to be used with 348 BPF_MAP_TYPE_SOCKMAP. 349 350config NET_FLOW_LIMIT 351 bool 352 depends on RPS 353 default y 354 help 355 The network stack has to drop packets when a receive processing CPU's 356 backlog reaches netdev_max_backlog. If a few out of many active flows 357 generate the vast majority of load, drop their traffic earlier to 358 maintain capacity for the other flows. This feature provides servers 359 with many clients some protection against DoS by a single (spoofed) 360 flow that greatly exceeds average workload. 361 362menu "Network testing" 363 364config NET_PKTGEN 365 tristate "Packet Generator (USE WITH CAUTION)" 366 depends on INET && PROC_FS 367 help 368 This module will inject preconfigured packets, at a configurable 369 rate, out of a given interface. It is used for network interface 370 stress testing and performance analysis. If you don't understand 371 what was just said, you don't need it: say N. 372 373 Documentation on how to use the packet generator can be found 374 at <file:Documentation/networking/pktgen.rst>. 375 376 To compile this code as a module, choose M here: the 377 module will be called pktgen. 378 379config NET_DROP_MONITOR 380 tristate "Network packet drop alerting service" 381 depends on INET && TRACEPOINTS 382 help 383 This feature provides an alerting service to userspace in the 384 event that packets are discarded in the network stack. Alerts 385 are broadcast via netlink socket to any listening user space 386 process. If you don't need network drop alerts, or if you are ok 387 just checking the various proc files and other utilities for 388 drop statistics, say N here. 389 390endmenu 391 392endmenu 393 394source "net/ax25/Kconfig" 395source "net/can/Kconfig" 396source "net/bluetooth/Kconfig" 397source "net/rxrpc/Kconfig" 398source "net/kcm/Kconfig" 399source "net/strparser/Kconfig" 400source "net/mctp/Kconfig" 401 402config FIB_RULES 403 bool 404 405menuconfig WIRELESS 406 bool "Wireless" 407 depends on !S390 408 default y 409 410if WIRELESS 411 412source "net/wireless/Kconfig" 413source "net/mac80211/Kconfig" 414 415endif # WIRELESS 416 417source "net/rfkill/Kconfig" 418source "net/9p/Kconfig" 419source "net/caif/Kconfig" 420source "net/ceph/Kconfig" 421source "net/nfc/Kconfig" 422source "net/psample/Kconfig" 423source "net/ife/Kconfig" 424 425config LWTUNNEL 426 bool "Network light weight tunnels" 427 help 428 This feature provides an infrastructure to support light weight 429 tunnels like mpls. There is no netdevice associated with a light 430 weight tunnel endpoint. Tunnel encapsulation parameters are stored 431 with light weight tunnel state associated with fib routes. 432 433config LWTUNNEL_BPF 434 bool "Execute BPF program as route nexthop action" 435 depends on LWTUNNEL && INET 436 default y if LWTUNNEL=y 437 help 438 Allows to run BPF programs as a nexthop action following a route 439 lookup for incoming and outgoing packets. 440 441config DST_CACHE 442 bool 443 default n 444 445config GRO_CELLS 446 bool 447 default n 448 449config SOCK_VALIDATE_XMIT 450 bool 451 452config NET_SELFTESTS 453 def_tristate PHYLIB 454 depends on PHYLIB && INET 455 456config NET_SOCK_MSG 457 bool 458 default n 459 help 460 The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or 461 ULPs (upper layer modules, e.g. TLS) to process L7 application data 462 with the help of BPF programs. 463 464config NET_DEVLINK 465 bool 466 default n 467 468config PAGE_POOL 469 bool 470 471config PAGE_POOL_STATS 472 default n 473 bool "Page pool stats" 474 depends on PAGE_POOL 475 help 476 Enable page pool statistics to track page allocation and recycling 477 in page pools. This option incurs additional CPU cost in allocation 478 and recycle paths and additional memory cost to store the statistics. 479 These statistics are only available if this option is enabled and if 480 the driver using the page pool supports exporting this data. 481 482 If unsure, say N. 483 484config FAILOVER 485 tristate "Generic failover module" 486 help 487 The failover module provides a generic interface for paravirtual 488 drivers to register a netdev and a set of ops with a failover 489 instance. The ops are used as event handlers that get called to 490 handle netdev register/unregister/link change/name change events 491 on slave pci ethernet devices with the same mac address as the 492 failover netdev. This enables paravirtual drivers to use a 493 VF as an accelerated low latency datapath. It also allows live 494 migration of VMs with direct attached VFs by failing over to the 495 paravirtual datapath when the VF is unplugged. 496 497config ETHTOOL_NETLINK 498 bool "Netlink interface for ethtool" 499 default y 500 help 501 An alternative userspace interface for ethtool based on generic 502 netlink. It provides better extensibility and some new features, 503 e.g. notification messages. 504 505config NETDEV_ADDR_LIST_TEST 506 tristate "Unit tests for device address list" 507 default KUNIT_ALL_TESTS 508 depends on KUNIT 509 510config NET_TEST 511 tristate "KUnit tests for networking" if !KUNIT_ALL_TESTS 512 depends on KUNIT 513 default KUNIT_ALL_TESTS 514 help 515 KUnit tests covering core networking infra, such as sk_buff. 516 517 If unsure, say N. 518 519endif # if NET 520