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