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