1 # SPDX-License-Identifier: GPL-2.0-only
3 # Network configuration
7 bool "Networking support"
9 select GENERIC_NET_UTILS
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
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>.
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>.
29 config WANT_COMPAT_NETLINK_MESSAGES
32 This option can be selected by other options that need compat
35 config COMPAT_NETLINK_MESSAGES
38 depends on WEXT_CORE || WANT_COMPAT_NETLINK_MESSAGES
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.
46 Newly written code should NEVER need this option but do
47 compat-independent messages instead!
66 menu "Networking options"
68 source "net/packet/Kconfig"
69 source "net/unix/Kconfig"
70 source "net/tls/Kconfig"
71 source "net/xfrm/Kconfig"
72 source "net/iucv/Kconfig"
73 source "net/smc/Kconfig"
74 source "net/xdp/Kconfig"
78 depends on SUNRPC || NVME_TARGET_TCP || NVME_TCP
81 config NET_HANDSHAKE_KUNIT_TEST
82 tristate "KUnit tests for the handshake upcall mechanism" if !KUNIT_ALL_TESTS
83 default KUNIT_ALL_TESTS
86 This builds the KUnit tests for the handshake upcall mechanism.
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.
93 For more information on KUnit and unit tests in general, refer
94 to the KUnit documentation in Documentation/dev-tools/kunit/.
97 bool "TCP/IP networking"
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!).
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>.
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>.
119 source "net/ipv4/Kconfig"
120 source "net/ipv6/Kconfig"
121 source "net/netlabel/Kconfig"
122 source "net/mptcp/Kconfig"
126 config NETWORK_SECMARK
127 bool "Security Marking"
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.
133 config NET_PTP_CLASSIFY
136 config NETWORK_PHY_TIMESTAMPING
137 bool "Timestamping in PHY devices"
138 select NET_PTP_CLASSIFY
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
145 If you are unsure how to answer this question, answer N.
148 bool "Network packet filtering framework (Netfilter)"
150 Netfilter is a framework for filtering and mangling network packets
151 that pass through your Linux box.
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
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).
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.
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
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
202 config NETFILTER_ADVANCED
203 bool "Advanced netfilter configuration"
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'.
213 config BRIDGE_NETFILTER
214 tristate "Bridged IP/ARP packets filtering"
216 depends on NETFILTER && INET
217 depends on NETFILTER_ADVANCED
218 select NETFILTER_FAMILY_BRIDGE
219 select SKB_EXTENSIONS
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
229 source "net/netfilter/Kconfig"
230 source "net/ipv4/netfilter/Kconfig"
231 source "net/ipv6/netfilter/Kconfig"
232 source "net/bridge/netfilter/Kconfig"
236 source "net/dccp/Kconfig"
237 source "net/sctp/Kconfig"
238 source "net/rds/Kconfig"
239 source "net/tipc/Kconfig"
240 source "net/atm/Kconfig"
241 source "net/l2tp/Kconfig"
242 source "net/802/Kconfig"
243 source "net/bridge/Kconfig"
244 source "net/dsa/Kconfig"
245 source "net/8021q/Kconfig"
246 source "net/llc/Kconfig"
247 source "net/appletalk/Kconfig"
248 source "net/x25/Kconfig"
249 source "net/lapb/Kconfig"
250 source "net/phonet/Kconfig"
251 source "net/6lowpan/Kconfig"
252 source "net/ieee802154/Kconfig"
253 source "net/mac802154/Kconfig"
254 source "net/sched/Kconfig"
255 source "net/dcb/Kconfig"
256 source "net/dns_resolver/Kconfig"
257 source "net/batman-adv/Kconfig"
258 source "net/openvswitch/Kconfig"
259 source "net/vmw_vsock/Kconfig"
260 source "net/netlink/Kconfig"
261 source "net/mpls/Kconfig"
262 source "net/nsh/Kconfig"
263 source "net/hsr/Kconfig"
264 source "net/switchdev/Kconfig"
265 source "net/l3mdev/Kconfig"
266 source "net/qrtr/Kconfig"
267 source "net/ncsi/Kconfig"
269 config PCPU_DEV_REFCNT
270 bool "Use percpu variables to maintain network device refcount"
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).
278 int "Maximum number of fragments per skb_shared_info"
282 Having more fragments per skb_shared_info can help GRO efficiency.
283 This helps BIG TCP workloads, but might expose bugs in some
285 This also increases memory overhead of small packets,
286 and in drivers using build_skb().
291 depends on SMP && SYSFS
300 config SOCK_RX_QUEUE_MAPPING
306 select SOCK_RX_QUEUE_MAPPING
312 config CGROUP_NET_PRIO
313 bool "Network priority cgroup"
315 select SOCK_CGROUP_DATA
317 Cgroup subsystem for use in assigning processes to network priorities on
318 a per-interface basis.
320 config CGROUP_NET_CLASSID
321 bool "Network classid cgroup"
323 select SOCK_CGROUP_DATA
325 Cgroup subsystem for use as general purpose socket classid marker that is
326 being used in cls_cgroup and for netfilter matching.
328 config NET_RX_BUSY_POLL
330 default y if !PREEMPT_RT || (PREEMPT_RT && !NETCONSOLE)
338 config BPF_STREAM_PARSER
339 bool "enable BPF STREAM_PARSER"
341 depends on BPF_SYSCALL
342 depends on CGROUP_BPF
346 Enabling this allows a TCP stream parser to be used with
347 BPF_MAP_TYPE_SOCKMAP.
349 config NET_FLOW_LIMIT
354 The network stack has to drop packets when a receive processing CPU's
355 backlog reaches netdev_max_backlog. If a few out of many active flows
356 generate the vast majority of load, drop their traffic earlier to
357 maintain capacity for the other flows. This feature provides servers
358 with many clients some protection against DoS by a single (spoofed)
359 flow that greatly exceeds average workload.
361 menu "Network testing"
364 tristate "Packet Generator (USE WITH CAUTION)"
365 depends on INET && PROC_FS
367 This module will inject preconfigured packets, at a configurable
368 rate, out of a given interface. It is used for network interface
369 stress testing and performance analysis. If you don't understand
370 what was just said, you don't need it: say N.
372 Documentation on how to use the packet generator can be found
373 at <file:Documentation/networking/pktgen.rst>.
375 To compile this code as a module, choose M here: the
376 module will be called pktgen.
378 config NET_DROP_MONITOR
379 tristate "Network packet drop alerting service"
380 depends on INET && TRACEPOINTS
382 This feature provides an alerting service to userspace in the
383 event that packets are discarded in the network stack. Alerts
384 are broadcast via netlink socket to any listening user space
385 process. If you don't need network drop alerts, or if you are ok
386 just checking the various proc files and other utilities for
387 drop statistics, say N here.
393 source "net/ax25/Kconfig"
394 source "net/can/Kconfig"
395 source "net/bluetooth/Kconfig"
396 source "net/rxrpc/Kconfig"
397 source "net/kcm/Kconfig"
398 source "net/strparser/Kconfig"
399 source "net/mctp/Kconfig"
411 source "net/wireless/Kconfig"
412 source "net/mac80211/Kconfig"
416 source "net/rfkill/Kconfig"
417 source "net/9p/Kconfig"
418 source "net/caif/Kconfig"
419 source "net/ceph/Kconfig"
420 source "net/nfc/Kconfig"
421 source "net/psample/Kconfig"
422 source "net/ife/Kconfig"
425 bool "Network light weight tunnels"
427 This feature provides an infrastructure to support light weight
428 tunnels like mpls. There is no netdevice associated with a light
429 weight tunnel endpoint. Tunnel encapsulation parameters are stored
430 with light weight tunnel state associated with fib routes.
433 bool "Execute BPF program as route nexthop action"
434 depends on LWTUNNEL && INET
435 default y if LWTUNNEL=y
437 Allows to run BPF programs as a nexthop action following a route
438 lookup for incoming and outgoing packets.
448 config SOCK_VALIDATE_XMIT
453 depends on PHYLIB && INET
459 The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or
460 ULPs (upper layer modules, e.g. TLS) to process L7 application data
461 with the help of BPF programs.
470 config PAGE_POOL_STATS
472 bool "Page pool stats"
475 Enable page pool statistics to track page allocation and recycling
476 in page pools. This option incurs additional CPU cost in allocation
477 and recycle paths and additional memory cost to store the statistics.
478 These statistics are only available if this option is enabled and if
479 the driver using the page pool supports exporting this data.
484 tristate "Generic failover module"
486 The failover module provides a generic interface for paravirtual
487 drivers to register a netdev and a set of ops with a failover
488 instance. The ops are used as event handlers that get called to
489 handle netdev register/unregister/link change/name change events
490 on slave pci ethernet devices with the same mac address as the
491 failover netdev. This enables paravirtual drivers to use a
492 VF as an accelerated low latency datapath. It also allows live
493 migration of VMs with direct attached VFs by failing over to the
494 paravirtual datapath when the VF is unplugged.
496 config ETHTOOL_NETLINK
497 bool "Netlink interface for ethtool"
500 An alternative userspace interface for ethtool based on generic
501 netlink. It provides better extensibility and some new features,
502 e.g. notification messages.
504 config NETDEV_ADDR_LIST_TEST
505 tristate "Unit tests for device address list"
506 default KUNIT_ALL_TESTS
510 tristate "KUnit tests for networking" if !KUNIT_ALL_TESTS
512 default KUNIT_ALL_TESTS
514 KUnit tests covering core networking infra, such as sk_buff.