1 # SPDX-License-Identifier: GPL-2.0-only 2 # 3 # Network configuration 4 # 5 6 menuconfig 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 27 if NET 28 29 config WANT_COMPAT_NETLINK_MESSAGES 30 bool 31 help 32 This option can be selected by other options that need compat 33 netlink messages. 34 35 config 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 49 config NET_INGRESS 50 bool 51 52 config NET_EGRESS 53 bool 54 55 config NET_XGRESS 56 select NET_INGRESS 57 select NET_EGRESS 58 bool 59 60 config NET_REDIRECT 61 bool 62 63 config SKB_DECRYPTED 64 bool 65 66 config SKB_EXTENSIONS 67 bool 68 69 menu "Networking options" 70 71 source "net/packet/Kconfig" 72 source "net/unix/Kconfig" 73 source "net/tls/Kconfig" 74 source "net/xfrm/Kconfig" 75 source "net/iucv/Kconfig" 76 source "net/smc/Kconfig" 77 source "net/xdp/Kconfig" 78 79 config NET_HANDSHAKE 80 bool 81 depends on SUNRPC || NVME_TARGET_TCP || NVME_TCP 82 default y 83 84 config NET_HANDSHAKE_KUNIT_TEST 85 tristate "KUnit tests for the handshake upcall mechanism" if !KUNIT_ALL_TESTS 86 default KUNIT_ALL_TESTS 87 depends on KUNIT 88 help 89 This builds the KUnit tests for the handshake upcall mechanism. 90 91 KUnit tests run during boot and output the results to the debug 92 log in TAP format (https://testanything.org/). Only useful for 93 kernel devs running KUnit test harness and are not for inclusion 94 into a production build. 95 96 For more information on KUnit and unit tests in general, refer 97 to the KUnit documentation in Documentation/dev-tools/kunit/. 98 99 config INET 100 bool "TCP/IP networking" 101 help 102 These are the protocols used on the Internet and on most local 103 Ethernets. It is highly recommended to say Y here (this will enlarge 104 your kernel by about 400 KB), since some programs (e.g. the X window 105 system) use TCP/IP even if your machine is not connected to any 106 other computer. You will get the so-called loopback device which 107 allows you to ping yourself (great fun, that!). 108 109 For an excellent introduction to Linux networking, please read the 110 Linux Networking HOWTO, available from 111 <http://www.tldp.org/docs.html#howto>. 112 113 If you say Y here and also to "/proc file system support" and 114 "Sysctl support" below, you can change various aspects of the 115 behavior of the TCP/IP code by writing to the (virtual) files in 116 /proc/sys/net/ipv4/*; the options are explained in the file 117 <file:Documentation/networking/ip-sysctl.rst>. 118 119 Short answer: say Y. 120 121 if INET 122 source "net/ipv4/Kconfig" 123 source "net/ipv6/Kconfig" 124 source "net/netlabel/Kconfig" 125 source "net/mptcp/Kconfig" 126 127 endif # if INET 128 129 config NETWORK_SECMARK 130 bool "Security Marking" 131 help 132 This enables security marking of network packets, similar 133 to nfmark, but designated for security purposes. 134 If you are unsure how to answer this question, answer N. 135 136 config NET_PTP_CLASSIFY 137 def_bool n 138 139 config NETWORK_PHY_TIMESTAMPING 140 bool "Timestamping in PHY devices" 141 select NET_PTP_CLASSIFY 142 help 143 This allows timestamping of network packets by PHYs (or 144 other MII bus snooping devices) with hardware timestamping 145 capabilities. This option adds some overhead in the transmit 146 and receive paths. 147 148 If you are unsure how to answer this question, answer N. 149 150 menuconfig NETFILTER 151 bool "Network packet filtering framework (Netfilter)" 152 help 153 Netfilter is a framework for filtering and mangling network packets 154 that pass through your Linux box. 155 156 The most common use of packet filtering is to run your Linux box as 157 a firewall protecting a local network from the Internet. The type of 158 firewall provided by this kernel support is called a "packet 159 filter", which means that it can reject individual network packets 160 based on type, source, destination etc. The other kind of firewall, 161 a "proxy-based" one, is more secure but more intrusive and more 162 bothersome to set up; it inspects the network traffic much more 163 closely, modifies it and has knowledge about the higher level 164 protocols, which a packet filter lacks. Moreover, proxy-based 165 firewalls often require changes to the programs running on the local 166 clients. Proxy-based firewalls don't need support by the kernel, but 167 they are often combined with a packet filter, which only works if 168 you say Y here. 169 170 You should also say Y here if you intend to use your Linux box as 171 the gateway to the Internet for a local network of machines without 172 globally valid IP addresses. This is called "masquerading": if one 173 of the computers on your local network wants to send something to 174 the outside, your box can "masquerade" as that computer, i.e. it 175 forwards the traffic to the intended outside destination, but 176 modifies the packets to make it look like they came from the 177 firewall box itself. It works both ways: if the outside host 178 replies, the Linux box will silently forward the traffic to the 179 correct local computer. This way, the computers on your local net 180 are completely invisible to the outside world, even though they can 181 reach the outside and can receive replies. It is even possible to 182 run globally visible servers from within a masqueraded local network 183 using a mechanism called portforwarding. Masquerading is also often 184 called NAT (Network Address Translation). 185 186 Another use of Netfilter is in transparent proxying: if a machine on 187 the local network tries to connect to an outside host, your Linux 188 box can transparently forward the traffic to a local server, 189 typically a caching proxy server. 190 191 Yet another use of Netfilter is building a bridging firewall. Using 192 a bridge with Network packet filtering enabled makes iptables "see" 193 the bridged traffic. For filtering on the lower network and Ethernet 194 protocols over the bridge, use ebtables (under bridge netfilter 195 configuration). 196 197 Various modules exist for netfilter which replace the previous 198 masquerading (ipmasqadm), packet filtering (ipchains), transparent 199 proxying, and portforwarding mechanisms. Please see 200 <file:Documentation/Changes> under "iptables" for the location of 201 these packages. 202 203 if NETFILTER 204 205 config NETFILTER_ADVANCED 206 bool "Advanced netfilter configuration" 207 depends on NETFILTER 208 default y 209 help 210 If you say Y here you can select between all the netfilter modules. 211 If you say N the more unusual ones will not be shown and the 212 basic ones needed by most people will default to 'M'. 213 214 If unsure, say Y. 215 216 config BRIDGE_NETFILTER 217 tristate "Bridged IP/ARP packets filtering" 218 depends on BRIDGE 219 depends on NETFILTER && INET 220 depends on NETFILTER_ADVANCED 221 select NETFILTER_FAMILY_BRIDGE 222 select SKB_EXTENSIONS 223 help 224 Enabling this option will let arptables resp. iptables see bridged 225 ARP resp. IP traffic. If you want a bridging firewall, you probably 226 want this option enabled. 227 Enabling or disabling this option doesn't enable or disable 228 ebtables. 229 230 If unsure, say N. 231 232 source "net/netfilter/Kconfig" 233 source "net/ipv4/netfilter/Kconfig" 234 source "net/ipv6/netfilter/Kconfig" 235 source "net/bridge/netfilter/Kconfig" 236 237 endif 238 239 source "net/dccp/Kconfig" 240 source "net/sctp/Kconfig" 241 source "net/rds/Kconfig" 242 source "net/tipc/Kconfig" 243 source "net/atm/Kconfig" 244 source "net/l2tp/Kconfig" 245 source "net/802/Kconfig" 246 source "net/bridge/Kconfig" 247 source "net/dsa/Kconfig" 248 source "net/8021q/Kconfig" 249 source "net/llc/Kconfig" 250 source "net/appletalk/Kconfig" 251 source "net/x25/Kconfig" 252 source "net/lapb/Kconfig" 253 source "net/phonet/Kconfig" 254 source "net/6lowpan/Kconfig" 255 source "net/ieee802154/Kconfig" 256 source "net/mac802154/Kconfig" 257 source "net/sched/Kconfig" 258 source "net/dcb/Kconfig" 259 source "net/dns_resolver/Kconfig" 260 source "net/batman-adv/Kconfig" 261 source "net/openvswitch/Kconfig" 262 source "net/vmw_vsock/Kconfig" 263 source "net/netlink/Kconfig" 264 source "net/mpls/Kconfig" 265 source "net/nsh/Kconfig" 266 source "net/hsr/Kconfig" 267 source "net/switchdev/Kconfig" 268 source "net/l3mdev/Kconfig" 269 source "net/qrtr/Kconfig" 270 source "net/ncsi/Kconfig" 271 272 config PCPU_DEV_REFCNT 273 bool "Use percpu variables to maintain network device refcount" 274 depends on SMP 275 default y 276 help 277 network device refcount are using per cpu variables if this option is set. 278 This can be forced to N to detect underflows (with a performance drop). 279 280 config MAX_SKB_FRAGS 281 int "Maximum number of fragments per skb_shared_info" 282 range 17 45 283 default 17 284 help 285 Having more fragments per skb_shared_info can help GRO efficiency. 286 This helps BIG TCP workloads, but might expose bugs in some 287 legacy drivers. 288 This also increases memory overhead of small packets, 289 and in drivers using build_skb(). 290 If unsure, say 17. 291 292 config RPS 293 bool "Receive packet steering" 294 depends on SMP && SYSFS 295 default y 296 help 297 Software receive side packet steering (RPS) distributes the 298 load of received packet processing across multiple CPUs. 299 300 config RFS_ACCEL 301 bool "Hardware acceleration of RFS" 302 depends on RPS 303 select CPU_RMAP 304 default y 305 help 306 Allowing drivers for multiqueue hardware with flow filter tables to 307 accelerate RFS. 308 309 config SOCK_RX_QUEUE_MAPPING 310 bool 311 312 config XPS 313 bool 314 depends on SMP 315 select SOCK_RX_QUEUE_MAPPING 316 default y 317 318 config HWBM 319 bool 320 321 config CGROUP_NET_PRIO 322 bool "Network priority cgroup" 323 depends on CGROUPS 324 select SOCK_CGROUP_DATA 325 help 326 Cgroup subsystem for use in assigning processes to network priorities on 327 a per-interface basis. 328 329 config CGROUP_NET_CLASSID 330 bool "Network classid cgroup" 331 depends on CGROUPS 332 select SOCK_CGROUP_DATA 333 help 334 Cgroup subsystem for use as general purpose socket classid marker that is 335 being used in cls_cgroup and for netfilter matching. 336 337 config NET_RX_BUSY_POLL 338 bool 339 default y if !PREEMPT_RT || (PREEMPT_RT && !NETCONSOLE) 340 341 config BQL 342 bool 343 prompt "Enable Byte Queue Limits" 344 depends on SYSFS 345 select DQL 346 default y 347 348 config BPF_STREAM_PARSER 349 bool "enable BPF STREAM_PARSER" 350 depends on INET 351 depends on BPF_SYSCALL 352 depends on CGROUP_BPF 353 select STREAM_PARSER 354 select NET_SOCK_MSG 355 help 356 Enabling this allows a TCP stream parser to be used with 357 BPF_MAP_TYPE_SOCKMAP. 358 359 config NET_FLOW_LIMIT 360 bool "Net flow limit" 361 depends on RPS 362 default y 363 help 364 The network stack has to drop packets when a receive processing CPU's 365 backlog reaches netdev_max_backlog. If a few out of many active flows 366 generate the vast majority of load, drop their traffic earlier to 367 maintain capacity for the other flows. This feature provides servers 368 with many clients some protection against DoS by a single (spoofed) 369 flow that greatly exceeds average workload. 370 371 menu "Network testing" 372 373 config NET_PKTGEN 374 tristate "Packet Generator (USE WITH CAUTION)" 375 depends on INET && PROC_FS 376 help 377 This module will inject preconfigured packets, at a configurable 378 rate, out of a given interface. It is used for network interface 379 stress testing and performance analysis. If you don't understand 380 what was just said, you don't need it: say N. 381 382 Documentation on how to use the packet generator can be found 383 at <file:Documentation/networking/pktgen.rst>. 384 385 To compile this code as a module, choose M here: the 386 module will be called pktgen. 387 388 config NET_DROP_MONITOR 389 tristate "Network packet drop alerting service" 390 depends on INET && TRACEPOINTS 391 help 392 This feature provides an alerting service to userspace in the 393 event that packets are discarded in the network stack. Alerts 394 are broadcast via netlink socket to any listening user space 395 process. If you don't need network drop alerts, or if you are ok 396 just checking the various proc files and other utilities for 397 drop statistics, say N here. 398 399 endmenu 400 401 endmenu 402 403 source "net/ax25/Kconfig" 404 source "net/can/Kconfig" 405 source "net/bluetooth/Kconfig" 406 source "net/rxrpc/Kconfig" 407 source "net/kcm/Kconfig" 408 source "net/strparser/Kconfig" 409 source "net/mctp/Kconfig" 410 411 config FIB_RULES 412 bool 413 414 menuconfig WIRELESS 415 bool "Wireless" 416 depends on !S390 417 default y 418 419 if WIRELESS 420 421 source "net/wireless/Kconfig" 422 source "net/mac80211/Kconfig" 423 424 endif # WIRELESS 425 426 source "net/rfkill/Kconfig" 427 source "net/9p/Kconfig" 428 source "net/caif/Kconfig" 429 source "net/ceph/Kconfig" 430 source "net/nfc/Kconfig" 431 source "net/psample/Kconfig" 432 source "net/ife/Kconfig" 433 434 config LWTUNNEL 435 bool "Network light weight tunnels" 436 help 437 This feature provides an infrastructure to support light weight 438 tunnels like mpls. There is no netdevice associated with a light 439 weight tunnel endpoint. Tunnel encapsulation parameters are stored 440 with light weight tunnel state associated with fib routes. 441 442 config LWTUNNEL_BPF 443 bool "Execute BPF program as route nexthop action" 444 depends on LWTUNNEL && INET 445 default y if LWTUNNEL=y 446 help 447 Allows to run BPF programs as a nexthop action following a route 448 lookup for incoming and outgoing packets. 449 450 config DST_CACHE 451 bool 452 default n 453 454 config GRO_CELLS 455 bool 456 default n 457 458 config SOCK_VALIDATE_XMIT 459 bool 460 461 config NET_IEEE8021Q_HELPERS 462 bool 463 464 config NET_SELFTESTS 465 def_tristate PHYLIB 466 depends on PHYLIB && INET 467 468 config NET_SOCK_MSG 469 bool 470 default n 471 help 472 The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or 473 ULPs (upper layer modules, e.g. TLS) to process L7 application data 474 with the help of BPF programs. 475 476 config NET_DEVLINK 477 bool 478 default n 479 480 config PAGE_POOL 481 bool 482 483 config PAGE_POOL_STATS 484 default n 485 bool "Page pool stats" 486 depends on PAGE_POOL 487 help 488 Enable page pool statistics to track page allocation and recycling 489 in page pools. This option incurs additional CPU cost in allocation 490 and recycle paths and additional memory cost to store the statistics. 491 These statistics are only available if this option is enabled and if 492 the driver using the page pool supports exporting this data. 493 494 If unsure, say N. 495 496 config FAILOVER 497 tristate "Generic failover module" 498 help 499 The failover module provides a generic interface for paravirtual 500 drivers to register a netdev and a set of ops with a failover 501 instance. The ops are used as event handlers that get called to 502 handle netdev register/unregister/link change/name change events 503 on slave pci ethernet devices with the same mac address as the 504 failover netdev. This enables paravirtual drivers to use a 505 VF as an accelerated low latency datapath. It also allows live 506 migration of VMs with direct attached VFs by failing over to the 507 paravirtual datapath when the VF is unplugged. 508 509 config ETHTOOL_NETLINK 510 bool "Netlink interface for ethtool" 511 select DIMLIB 512 default y 513 help 514 An alternative userspace interface for ethtool based on generic 515 netlink. It provides better extensibility and some new features, 516 e.g. notification messages. 517 518 config NETDEV_ADDR_LIST_TEST 519 tristate "Unit tests for device address list" 520 default KUNIT_ALL_TESTS 521 depends on KUNIT 522 523 config NET_TEST 524 tristate "KUnit tests for networking" if !KUNIT_ALL_TESTS 525 depends on KUNIT 526 default KUNIT_ALL_TESTS 527 help 528 KUnit tests covering core networking infra, such as sk_buff. 529 530 If unsure, say N. 531 532 endif # if NET 533