xref: /linux/net/Kconfig (revision 26d74602)
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	depends on DMA_SHARED_BUFFER
72	depends on GENERIC_ALLOCATOR
73	depends on PAGE_POOL
74
75menu "Networking options"
76
77source "net/packet/Kconfig"
78source "net/unix/Kconfig"
79source "net/tls/Kconfig"
80source "net/xfrm/Kconfig"
81source "net/iucv/Kconfig"
82source "net/smc/Kconfig"
83source "net/xdp/Kconfig"
84
85config NET_HANDSHAKE
86	bool
87	depends on SUNRPC || NVME_TARGET_TCP || NVME_TCP
88	default y
89
90config NET_HANDSHAKE_KUNIT_TEST
91	tristate "KUnit tests for the handshake upcall mechanism" if !KUNIT_ALL_TESTS
92	default KUNIT_ALL_TESTS
93	depends on KUNIT
94	help
95	  This builds the KUnit tests for the handshake upcall mechanism.
96
97	  KUnit tests run during boot and output the results to the debug
98	  log in TAP format (https://testanything.org/). Only useful for
99	  kernel devs running KUnit test harness and are not for inclusion
100	  into a production build.
101
102	  For more information on KUnit and unit tests in general, refer
103	  to the KUnit documentation in Documentation/dev-tools/kunit/.
104
105config INET
106	bool "TCP/IP networking"
107	help
108	  These are the protocols used on the Internet and on most local
109	  Ethernets. It is highly recommended to say Y here (this will enlarge
110	  your kernel by about 400 KB), since some programs (e.g. the X window
111	  system) use TCP/IP even if your machine is not connected to any
112	  other computer. You will get the so-called loopback device which
113	  allows you to ping yourself (great fun, that!).
114
115	  For an excellent introduction to Linux networking, please read the
116	  Linux Networking HOWTO, available from
117	  <http://www.tldp.org/docs.html#howto>.
118
119	  If you say Y here and also to "/proc file system support" and
120	  "Sysctl support" below, you can change various aspects of the
121	  behavior of the TCP/IP code by writing to the (virtual) files in
122	  /proc/sys/net/ipv4/*; the options are explained in the file
123	  <file:Documentation/networking/ip-sysctl.rst>.
124
125	  Short answer: say Y.
126
127if INET
128source "net/ipv4/Kconfig"
129source "net/ipv6/Kconfig"
130source "net/netlabel/Kconfig"
131source "net/mptcp/Kconfig"
132
133endif # if INET
134
135config NETWORK_SECMARK
136	bool "Security Marking"
137	help
138	  This enables security marking of network packets, similar
139	  to nfmark, but designated for security purposes.
140	  If you are unsure how to answer this question, answer N.
141
142config NET_PTP_CLASSIFY
143	def_bool n
144
145config NETWORK_PHY_TIMESTAMPING
146	bool "Timestamping in PHY devices"
147	select NET_PTP_CLASSIFY
148	help
149	  This allows timestamping of network packets by PHYs (or
150	  other MII bus snooping devices) with hardware timestamping
151	  capabilities. This option adds some overhead in the transmit
152	  and receive paths.
153
154	  If you are unsure how to answer this question, answer N.
155
156menuconfig NETFILTER
157	bool "Network packet filtering framework (Netfilter)"
158	help
159	  Netfilter is a framework for filtering and mangling network packets
160	  that pass through your Linux box.
161
162	  The most common use of packet filtering is to run your Linux box as
163	  a firewall protecting a local network from the Internet. The type of
164	  firewall provided by this kernel support is called a "packet
165	  filter", which means that it can reject individual network packets
166	  based on type, source, destination etc. The other kind of firewall,
167	  a "proxy-based" one, is more secure but more intrusive and more
168	  bothersome to set up; it inspects the network traffic much more
169	  closely, modifies it and has knowledge about the higher level
170	  protocols, which a packet filter lacks. Moreover, proxy-based
171	  firewalls often require changes to the programs running on the local
172	  clients. Proxy-based firewalls don't need support by the kernel, but
173	  they are often combined with a packet filter, which only works if
174	  you say Y here.
175
176	  You should also say Y here if you intend to use your Linux box as
177	  the gateway to the Internet for a local network of machines without
178	  globally valid IP addresses. This is called "masquerading": if one
179	  of the computers on your local network wants to send something to
180	  the outside, your box can "masquerade" as that computer, i.e. it
181	  forwards the traffic to the intended outside destination, but
182	  modifies the packets to make it look like they came from the
183	  firewall box itself. It works both ways: if the outside host
184	  replies, the Linux box will silently forward the traffic to the
185	  correct local computer. This way, the computers on your local net
186	  are completely invisible to the outside world, even though they can
187	  reach the outside and can receive replies. It is even possible to
188	  run globally visible servers from within a masqueraded local network
189	  using a mechanism called portforwarding. Masquerading is also often
190	  called NAT (Network Address Translation).
191
192	  Another use of Netfilter is in transparent proxying: if a machine on
193	  the local network tries to connect to an outside host, your Linux
194	  box can transparently forward the traffic to a local server,
195	  typically a caching proxy server.
196
197	  Yet another use of Netfilter is building a bridging firewall. Using
198	  a bridge with Network packet filtering enabled makes iptables "see"
199	  the bridged traffic. For filtering on the lower network and Ethernet
200	  protocols over the bridge, use ebtables (under bridge netfilter
201	  configuration).
202
203	  Various modules exist for netfilter which replace the previous
204	  masquerading (ipmasqadm), packet filtering (ipchains), transparent
205	  proxying, and portforwarding mechanisms. Please see
206	  <file:Documentation/Changes> under "iptables" for the location of
207	  these packages.
208
209if NETFILTER
210
211config NETFILTER_ADVANCED
212	bool "Advanced netfilter configuration"
213	depends on NETFILTER
214	default y
215	help
216	  If you say Y here you can select between all the netfilter modules.
217	  If you say N the more unusual ones will not be shown and the
218	  basic ones needed by most people will default to 'M'.
219
220	  If unsure, say Y.
221
222config BRIDGE_NETFILTER
223	tristate "Bridged IP/ARP packets filtering"
224	depends on BRIDGE
225	depends on NETFILTER && INET
226	depends on NETFILTER_ADVANCED
227	select NETFILTER_FAMILY_BRIDGE
228	select SKB_EXTENSIONS
229	help
230	  Enabling this option will let arptables resp. iptables see bridged
231	  ARP resp. IP traffic. If you want a bridging firewall, you probably
232	  want this option enabled.
233	  Enabling or disabling this option doesn't enable or disable
234	  ebtables.
235
236	  If unsure, say N.
237
238source "net/netfilter/Kconfig"
239source "net/ipv4/netfilter/Kconfig"
240source "net/ipv6/netfilter/Kconfig"
241source "net/bridge/netfilter/Kconfig"
242
243endif
244
245source "net/dccp/Kconfig"
246source "net/sctp/Kconfig"
247source "net/rds/Kconfig"
248source "net/tipc/Kconfig"
249source "net/atm/Kconfig"
250source "net/l2tp/Kconfig"
251source "net/802/Kconfig"
252source "net/bridge/Kconfig"
253source "net/dsa/Kconfig"
254source "net/8021q/Kconfig"
255source "net/llc/Kconfig"
256source "net/appletalk/Kconfig"
257source "net/x25/Kconfig"
258source "net/lapb/Kconfig"
259source "net/phonet/Kconfig"
260source "net/6lowpan/Kconfig"
261source "net/ieee802154/Kconfig"
262source "net/mac802154/Kconfig"
263source "net/sched/Kconfig"
264source "net/dcb/Kconfig"
265source "net/dns_resolver/Kconfig"
266source "net/batman-adv/Kconfig"
267source "net/openvswitch/Kconfig"
268source "net/vmw_vsock/Kconfig"
269source "net/netlink/Kconfig"
270source "net/mpls/Kconfig"
271source "net/nsh/Kconfig"
272source "net/hsr/Kconfig"
273source "net/switchdev/Kconfig"
274source "net/l3mdev/Kconfig"
275source "net/qrtr/Kconfig"
276source "net/ncsi/Kconfig"
277
278config PCPU_DEV_REFCNT
279	bool "Use percpu variables to maintain network device refcount"
280	depends on SMP
281	default y
282	help
283	  network device refcount are using per cpu variables if this option is set.
284	  This can be forced to N to detect underflows (with a performance drop).
285
286config MAX_SKB_FRAGS
287	int "Maximum number of fragments per skb_shared_info"
288	range 17 45
289	default 17
290	help
291	  Having more fragments per skb_shared_info can help GRO efficiency.
292	  This helps BIG TCP workloads, but might expose bugs in some
293	  legacy drivers.
294	  This also increases memory overhead of small packets,
295	  and in drivers using build_skb().
296	  If unsure, say 17.
297
298config RPS
299	bool "Receive packet steering"
300	depends on SMP && SYSFS
301	default y
302	help
303	  Software receive side packet steering (RPS) distributes the
304	  load of received packet processing across multiple CPUs.
305
306config RFS_ACCEL
307	bool "Hardware acceleration of RFS"
308	depends on RPS
309	select CPU_RMAP
310	default y
311	help
312	  Allowing drivers for multiqueue hardware with flow filter tables to
313	  accelerate RFS.
314
315config SOCK_RX_QUEUE_MAPPING
316	bool
317
318config XPS
319	bool
320	depends on SMP
321	select SOCK_RX_QUEUE_MAPPING
322	default y
323
324config HWBM
325	bool
326
327config CGROUP_NET_PRIO
328	bool "Network priority cgroup"
329	depends on CGROUPS
330	select SOCK_CGROUP_DATA
331	help
332	  Cgroup subsystem for use in assigning processes to network priorities on
333	  a per-interface basis.
334
335config CGROUP_NET_CLASSID
336	bool "Network classid cgroup"
337	depends on CGROUPS
338	select SOCK_CGROUP_DATA
339	help
340	  Cgroup subsystem for use as general purpose socket classid marker that is
341	  being used in cls_cgroup and for netfilter matching.
342
343config NET_RX_BUSY_POLL
344	bool
345	default y if !PREEMPT_RT || (PREEMPT_RT && !NETCONSOLE)
346
347config BQL
348	bool
349	prompt "Enable Byte Queue Limits"
350	depends on SYSFS
351	select DQL
352	default y
353
354config BPF_STREAM_PARSER
355	bool "enable BPF STREAM_PARSER"
356	depends on INET
357	depends on BPF_SYSCALL
358	depends on CGROUP_BPF
359	select STREAM_PARSER
360	select NET_SOCK_MSG
361	help
362	  Enabling this allows a TCP stream parser to be used with
363	  BPF_MAP_TYPE_SOCKMAP.
364
365config NET_FLOW_LIMIT
366	bool "Net flow limit"
367	depends on RPS
368	default y
369	help
370	  The network stack has to drop packets when a receive processing CPU's
371	  backlog reaches netdev_max_backlog. If a few out of many active flows
372	  generate the vast majority of load, drop their traffic earlier to
373	  maintain capacity for the other flows. This feature provides servers
374	  with many clients some protection against DoS by a single (spoofed)
375	  flow that greatly exceeds average workload.
376
377menu "Network testing"
378
379config NET_PKTGEN
380	tristate "Packet Generator (USE WITH CAUTION)"
381	depends on INET && PROC_FS
382	help
383	  This module will inject preconfigured packets, at a configurable
384	  rate, out of a given interface.  It is used for network interface
385	  stress testing and performance analysis.  If you don't understand
386	  what was just said, you don't need it: say N.
387
388	  Documentation on how to use the packet generator can be found
389	  at <file:Documentation/networking/pktgen.rst>.
390
391	  To compile this code as a module, choose M here: the
392	  module will be called pktgen.
393
394config NET_DROP_MONITOR
395	tristate "Network packet drop alerting service"
396	depends on INET && TRACEPOINTS
397	help
398	  This feature provides an alerting service to userspace in the
399	  event that packets are discarded in the network stack.  Alerts
400	  are broadcast via netlink socket to any listening user space
401	  process.  If you don't need network drop alerts, or if you are ok
402	  just checking the various proc files and other utilities for
403	  drop statistics, say N here.
404
405endmenu
406
407endmenu
408
409source "net/ax25/Kconfig"
410source "net/can/Kconfig"
411source "net/bluetooth/Kconfig"
412source "net/rxrpc/Kconfig"
413source "net/kcm/Kconfig"
414source "net/strparser/Kconfig"
415source "net/mctp/Kconfig"
416
417config FIB_RULES
418	bool
419
420menuconfig WIRELESS
421	bool "Wireless"
422	depends on !S390
423	default y
424
425if WIRELESS
426
427source "net/wireless/Kconfig"
428source "net/mac80211/Kconfig"
429
430endif # WIRELESS
431
432source "net/rfkill/Kconfig"
433source "net/9p/Kconfig"
434source "net/caif/Kconfig"
435source "net/ceph/Kconfig"
436source "net/nfc/Kconfig"
437source "net/psample/Kconfig"
438source "net/ife/Kconfig"
439
440config LWTUNNEL
441	bool "Network light weight tunnels"
442	help
443	  This feature provides an infrastructure to support light weight
444	  tunnels like mpls. There is no netdevice associated with a light
445	  weight tunnel endpoint. Tunnel encapsulation parameters are stored
446	  with light weight tunnel state associated with fib routes.
447
448config LWTUNNEL_BPF
449	bool "Execute BPF program as route nexthop action"
450	depends on LWTUNNEL && INET
451	default y if LWTUNNEL=y
452	help
453	  Allows to run BPF programs as a nexthop action following a route
454	  lookup for incoming and outgoing packets.
455
456config DST_CACHE
457	bool
458	default n
459
460config GRO_CELLS
461	bool
462	default n
463
464config SOCK_VALIDATE_XMIT
465	bool
466
467config NET_IEEE8021Q_HELPERS
468	bool
469
470config NET_SELFTESTS
471	def_tristate PHYLIB
472	depends on PHYLIB && INET
473
474config NET_SOCK_MSG
475	bool
476	default n
477	help
478	  The NET_SOCK_MSG provides a framework for plain sockets (e.g. TCP) or
479	  ULPs (upper layer modules, e.g. TLS) to process L7 application data
480	  with the help of BPF programs.
481
482config NET_DEVLINK
483	bool
484	default n
485
486config PAGE_POOL
487	bool
488
489config PAGE_POOL_STATS
490	default n
491	bool "Page pool stats"
492	depends on PAGE_POOL
493	help
494	  Enable page pool statistics to track page allocation and recycling
495	  in page pools. This option incurs additional CPU cost in allocation
496	  and recycle paths and additional memory cost to store the statistics.
497	  These statistics are only available if this option is enabled and if
498	  the driver using the page pool supports exporting this data.
499
500	  If unsure, say N.
501
502config FAILOVER
503	tristate "Generic failover module"
504	help
505	  The failover module provides a generic interface for paravirtual
506	  drivers to register a netdev and a set of ops with a failover
507	  instance. The ops are used as event handlers that get called to
508	  handle netdev register/unregister/link change/name change events
509	  on slave pci ethernet devices with the same mac address as the
510	  failover netdev. This enables paravirtual drivers to use a
511	  VF as an accelerated low latency datapath. It also allows live
512	  migration of VMs with direct attached VFs by failing over to the
513	  paravirtual datapath when the VF is unplugged.
514
515config ETHTOOL_NETLINK
516	bool "Netlink interface for ethtool"
517	select DIMLIB
518	default y
519	help
520	  An alternative userspace interface for ethtool based on generic
521	  netlink. It provides better extensibility and some new features,
522	  e.g. notification messages.
523
524config NETDEV_ADDR_LIST_TEST
525	tristate "Unit tests for device address list"
526	default KUNIT_ALL_TESTS
527	depends on KUNIT
528
529config NET_TEST
530	tristate "KUnit tests for networking" if !KUNIT_ALL_TESTS
531	depends on KUNIT
532	default KUNIT_ALL_TESTS
533	help
534	  KUnit tests covering core networking infra, such as sk_buff.
535
536	  If unsure, say N.
537
538endif   # if NET
539