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 select GENERIC_ALLOCATOR 72 depends on DMA_SHARED_BUFFER 73 depends on PAGE_POOL 74 75config NET_SHAPER 76 bool 77 78config NET_CRC32C 79 bool 80 select CRC32 81 82menu "Networking options" 83 84source "net/packet/Kconfig" 85source "net/psp/Kconfig" 86source "net/unix/Kconfig" 87source "net/tls/Kconfig" 88source "net/xfrm/Kconfig" 89source "net/iucv/Kconfig" 90source "net/smc/Kconfig" 91source "net/xdp/Kconfig" 92 93config NET_HANDSHAKE 94 bool 95 depends on SUNRPC || NVME_TARGET_TCP || NVME_TCP 96 default y 97 98config NET_HANDSHAKE_KUNIT_TEST 99 tristate "KUnit tests for the handshake upcall mechanism" if !KUNIT_ALL_TESTS 100 default KUNIT_ALL_TESTS 101 depends on KUNIT 102 help 103 This builds the KUnit tests for the handshake upcall mechanism. 104 105 KUnit tests run during boot and output the results to the debug 106 log in TAP format (https://testanything.org/). Only useful for 107 kernel devs running KUnit test harness and are not for inclusion 108 into a production build. 109 110 For more information on KUnit and unit tests in general, refer 111 to the KUnit documentation in Documentation/dev-tools/kunit/. 112 113config INET 114 bool "TCP/IP networking" 115 help 116 These are the protocols used on the Internet and on most local 117 Ethernets. It is highly recommended to say Y here (this will enlarge 118 your kernel by about 400 KB), since some programs (e.g. the X window 119 system) use TCP/IP even if your machine is not connected to any 120 other computer. You will get the so-called loopback device which 121 allows you to ping yourself (great fun, that!). 122 123 For an excellent introduction to Linux networking, please read the 124 Linux Networking HOWTO, available from 125 <http://www.tldp.org/docs.html#howto>. 126 127 If you say Y here and also to "/proc file system support" and 128 "Sysctl support" below, you can change various aspects of the 129 behavior of the TCP/IP code by writing to the (virtual) files in 130 /proc/sys/net/ipv4/*; the options are explained in the file 131 <file:Documentation/networking/ip-sysctl.rst>. 132 133 Short answer: say Y. 134 135if INET 136source "net/ipv4/Kconfig" 137source "net/ipv6/Kconfig" 138source "net/netlabel/Kconfig" 139source "net/mptcp/Kconfig" 140 141endif # if INET 142 143config NETWORK_SECMARK 144 bool "Security Marking" 145 help 146 This enables security marking of network packets, similar 147 to nfmark, but designated for security purposes. 148 If you are unsure how to answer this question, answer N. 149 150config NET_PTP_CLASSIFY 151 def_bool n 152 153config NETWORK_PHY_TIMESTAMPING 154 bool "Timestamping in PHY devices" 155 select NET_PTP_CLASSIFY 156 help 157 This allows timestamping of network packets by PHYs (or 158 other MII bus snooping devices) with hardware timestamping 159 capabilities. This option adds some overhead in the transmit 160 and receive paths. 161 162 If you are unsure how to answer this question, answer N. 163 164menuconfig NETFILTER 165 bool "Network packet filtering framework (Netfilter)" 166 help 167 Netfilter is a framework for filtering and mangling network packets 168 that pass through your Linux box. 169 170 The most common use of packet filtering is to run your Linux box as 171 a firewall protecting a local network from the Internet. The type of 172 firewall provided by this kernel support is called a "packet 173 filter", which means that it can reject individual network packets 174 based on type, source, destination etc. The other kind of firewall, 175 a "proxy-based" one, is more secure but more intrusive and more 176 bothersome to set up; it inspects the network traffic much more 177 closely, modifies it and has knowledge about the higher level 178 protocols, which a packet filter lacks. Moreover, proxy-based 179 firewalls often require changes to the programs running on the local 180 clients. Proxy-based firewalls don't need support by the kernel, but 181 they are often combined with a packet filter, which only works if 182 you say Y here. 183 184 You should also say Y here if you intend to use your Linux box as 185 the gateway to the Internet for a local network of machines without 186 globally valid IP addresses. This is called "masquerading": if one 187 of the computers on your local network wants to send something to 188 the outside, your box can "masquerade" as that computer, i.e. it 189 forwards the traffic to the intended outside destination, but 190 modifies the packets to make it look like they came from the 191 firewall box itself. It works both ways: if the outside host 192 replies, the Linux box will silently forward the traffic to the 193 correct local computer. This way, the computers on your local net 194 are completely invisible to the outside world, even though they can 195 reach the outside and can receive replies. It is even possible to 196 run globally visible servers from within a masqueraded local network 197 using a mechanism called portforwarding. Masquerading is also often 198 called NAT (Network Address Translation). 199 200 Another use of Netfilter is in transparent proxying: if a machine on 201 the local network tries to connect to an outside host, your Linux 202 box can transparently forward the traffic to a local server, 203 typically a caching proxy server. 204 205 Yet another use of Netfilter is building a bridging firewall. Using 206 a bridge with Network packet filtering enabled makes iptables "see" 207 the bridged traffic. For filtering on the lower network and Ethernet 208 protocols over the bridge, use ebtables (under bridge netfilter 209 configuration). 210 211 Various modules exist for netfilter which replace the previous 212 masquerading (ipmasqadm), packet filtering (ipchains), transparent 213 proxying, and portforwarding mechanisms. Please see 214 <file:Documentation/Changes> under "iptables" for the location of 215 these packages. 216 217if NETFILTER 218 219config NETFILTER_ADVANCED 220 bool "Advanced netfilter configuration" 221 depends on NETFILTER 222 default y 223 help 224 If you say Y here you can select between all the netfilter modules. 225 If you say N the more unusual ones will not be shown and the 226 basic ones needed by most people will default to 'M'. 227 228 If unsure, say Y. 229 230config BRIDGE_NETFILTER 231 tristate "Bridged IP/ARP packets filtering" 232 depends on BRIDGE 233 depends on NETFILTER && INET 234 depends on NETFILTER_ADVANCED 235 select NETFILTER_FAMILY_BRIDGE 236 select SKB_EXTENSIONS 237 help 238 Enabling this option will let arptables resp. iptables see bridged 239 ARP resp. IP traffic. If you want a bridging firewall, you probably 240 want this option enabled. 241 Enabling or disabling this option doesn't enable or disable 242 ebtables. 243 244 If unsure, say N. 245 246source "net/netfilter/Kconfig" 247source "net/ipv4/netfilter/Kconfig" 248source "net/ipv6/netfilter/Kconfig" 249source "net/bridge/netfilter/Kconfig" 250 251endif # if NETFILTER 252 253source "net/sctp/Kconfig" 254source "net/rds/Kconfig" 255source "net/tipc/Kconfig" 256source "net/atm/Kconfig" 257source "net/l2tp/Kconfig" 258source "net/802/Kconfig" 259source "net/bridge/Kconfig" 260source "net/dsa/Kconfig" 261source "net/8021q/Kconfig" 262source "net/llc/Kconfig" 263source "net/appletalk/Kconfig" 264source "net/x25/Kconfig" 265source "net/lapb/Kconfig" 266source "net/phonet/Kconfig" 267source "net/6lowpan/Kconfig" 268source "net/ieee802154/Kconfig" 269source "net/mac802154/Kconfig" 270source "net/sched/Kconfig" 271source "net/dcb/Kconfig" 272source "net/dns_resolver/Kconfig" 273source "net/batman-adv/Kconfig" 274source "net/openvswitch/Kconfig" 275source "net/vmw_vsock/Kconfig" 276source "net/netlink/Kconfig" 277source "net/mpls/Kconfig" 278source "net/nsh/Kconfig" 279source "net/hsr/Kconfig" 280source "net/switchdev/Kconfig" 281source "net/l3mdev/Kconfig" 282source "net/qrtr/Kconfig" 283source "net/ncsi/Kconfig" 284 285config PCPU_DEV_REFCNT 286 bool "Use percpu variables to maintain network device refcount" 287 depends on SMP 288 default y 289 help 290 network device refcount are using per cpu variables if this option is set. 291 This can be forced to N to detect underflows (with a performance drop). 292 293config MAX_SKB_FRAGS 294 int "Maximum number of fragments per skb_shared_info" 295 range 17 45 296 default 17 297 help 298 Having more fragments per skb_shared_info can help GRO efficiency. 299 This helps BIG TCP workloads, but might expose bugs in some 300 legacy drivers. 301 This also increases memory overhead of small packets, 302 and in drivers using build_skb(). 303 If unsure, say 17. 304 305config RPS 306 bool "Receive packet steering" 307 depends on SMP && SYSFS 308 default y 309 help 310 Software receive side packet steering (RPS) distributes the 311 load of received packet processing across multiple CPUs. 312 313config RFS_ACCEL 314 bool "Hardware acceleration of RFS" 315 depends on RPS 316 select CPU_RMAP 317 default y 318 help 319 Allowing drivers for multiqueue hardware with flow filter tables to 320 accelerate RFS. 321 322config SOCK_RX_QUEUE_MAPPING 323 bool 324 325config XPS 326 bool 327 depends on SMP 328 select SOCK_RX_QUEUE_MAPPING 329 default y 330 331config HWBM 332 bool 333 334config CGROUP_NET_PRIO 335 bool "Network priority cgroup" 336 depends on CGROUPS 337 select SOCK_CGROUP_DATA 338 help 339 Cgroup subsystem for use in assigning processes to network priorities on 340 a per-interface basis. 341 342config CGROUP_NET_CLASSID 343 bool "Network classid cgroup" 344 depends on CGROUPS 345 select SOCK_CGROUP_DATA 346 help 347 Cgroup subsystem for use as general purpose socket classid marker that is 348 being used in cls_cgroup and for netfilter matching. 349 350config NET_RX_BUSY_POLL 351 bool 352 default y if !PREEMPT_RT || (PREEMPT_RT && !NETCONSOLE) 353 354config BQL 355 bool 356 prompt "Enable Byte Queue Limits" 357 depends on SYSFS 358 select DQL 359 default y 360 361config BPF_STREAM_PARSER 362 bool "enable BPF STREAM_PARSER" 363 depends on INET 364 depends on BPF_SYSCALL 365 depends on CGROUP_BPF 366 select STREAM_PARSER 367 select NET_SOCK_MSG 368 help 369 Enabling this allows a TCP stream parser to be used with 370 BPF_MAP_TYPE_SOCKMAP. 371 372config NET_FLOW_LIMIT 373 bool "Net flow limit" 374 depends on RPS 375 default y 376 help 377 The network stack has to drop packets when a receive processing CPU's 378 backlog reaches netdev_max_backlog. If a few out of many active flows 379 generate the vast majority of load, drop their traffic earlier to 380 maintain capacity for the other flows. This feature provides servers 381 with many clients some protection against DoS by a single (spoofed) 382 flow that greatly exceeds average workload. 383 384menu "Network testing" 385 386config NET_PKTGEN 387 tristate "Packet Generator (USE WITH CAUTION)" 388 depends on INET && PROC_FS 389 help 390 This module will inject preconfigured packets, at a configurable 391 rate, out of a given interface. It is used for network interface 392 stress testing and performance analysis. If you don't understand 393 what was just said, you don't need it: say N. 394 395 Documentation on how to use the packet generator can be found 396 at <file:Documentation/networking/pktgen.rst>. 397 398 To compile this code as a module, choose M here: the 399 module will be called pktgen. 400 401config NET_DROP_MONITOR 402 tristate "Network packet drop alerting service" 403 depends on INET && TRACEPOINTS 404 help 405 This feature provides an alerting service to userspace in the 406 event that packets are discarded in the network stack. Alerts 407 are broadcast via netlink socket to any listening user space 408 process. If you don't need network drop alerts, or if you are ok 409 just checking the various proc files and other utilities for 410 drop statistics, say N here. 411 412endmenu # Network testing 413 414endmenu # Networking options 415 416source "net/ax25/Kconfig" 417source "net/can/Kconfig" 418source "net/bluetooth/Kconfig" 419source "net/rxrpc/Kconfig" 420source "net/kcm/Kconfig" 421source "net/strparser/Kconfig" 422source "net/mctp/Kconfig" 423 424config FIB_RULES 425 bool 426 427menuconfig WIRELESS 428 bool "Wireless" 429 depends on !S390 430 default y 431 432if WIRELESS 433 434source "net/wireless/Kconfig" 435source "net/mac80211/Kconfig" 436 437endif # WIRELESS 438 439source "net/rfkill/Kconfig" 440source "net/9p/Kconfig" 441source "net/caif/Kconfig" 442source "net/ceph/Kconfig" 443source "net/nfc/Kconfig" 444source "net/psample/Kconfig" 445source "net/ife/Kconfig" 446 447config LWTUNNEL 448 bool "Network light weight tunnels" 449 help 450 This feature provides an infrastructure to support light weight 451 tunnels like mpls. There is no netdevice associated with a light 452 weight tunnel endpoint. Tunnel encapsulation parameters are stored 453 with light weight tunnel state associated with fib routes. 454 455config LWTUNNEL_BPF 456 bool "Execute BPF program as route nexthop action" 457 depends on LWTUNNEL && INET 458 default y if LWTUNNEL=y 459 help 460 Allows to run BPF programs as a nexthop action following a route 461 lookup for incoming and outgoing packets. 462 463config DST_CACHE 464 bool 465 default n 466 467config GRO_CELLS 468 bool 469 default n 470 471config SOCK_VALIDATE_XMIT 472 bool 473 474config NET_IEEE8021Q_HELPERS 475 bool 476 477config NET_SELFTESTS 478 def_tristate PHYLIB 479 depends on PHYLIB && INET 480 481config NET_SOCK_MSG 482 bool 483 default n 484 help 485 The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or 486 ULPs (upper layer modules, e.g. TLS) to process L7 application data 487 with the help of BPF programs. 488 489config NET_DEVLINK 490 bool 491 default n 492 493config PAGE_POOL 494 bool 495 496config PAGE_POOL_STATS 497 default n 498 bool "Page pool stats" 499 depends on PAGE_POOL 500 help 501 Enable page pool statistics to track page allocation and recycling 502 in page pools. This option incurs additional CPU cost in allocation 503 and recycle paths and additional memory cost to store the statistics. 504 These statistics are only available if this option is enabled and if 505 the driver using the page pool supports exporting this data. 506 507 If unsure, say N. 508 509config FAILOVER 510 tristate "Generic failover module" 511 help 512 The failover module provides a generic interface for paravirtual 513 drivers to register a netdev and a set of ops with a failover 514 instance. The ops are used as event handlers that get called to 515 handle netdev register/unregister/link change/name change events 516 on slave pci ethernet devices with the same mac address as the 517 failover netdev. This enables paravirtual drivers to use a 518 VF as an accelerated low latency datapath. It also allows live 519 migration of VMs with direct attached VFs by failing over to the 520 paravirtual datapath when the VF is unplugged. 521 522config ETHTOOL_NETLINK 523 bool "Netlink interface for ethtool" 524 select DIMLIB 525 default y 526 help 527 An alternative userspace interface for ethtool based on generic 528 netlink. It provides better extensibility and some new features, 529 e.g. notification messages. 530 531config NETDEV_ADDR_LIST_TEST 532 tristate "Unit tests for device address list" 533 default KUNIT_ALL_TESTS 534 depends on KUNIT 535 536config NET_TEST 537 tristate "KUnit tests for networking" if !KUNIT_ALL_TESTS 538 depends on KUNIT 539 default KUNIT_ALL_TESTS 540 help 541 KUnit tests covering core networking infra, such as sk_buff. 542 543 If unsure, say N. 544 545endif # if NET 546