2 # Traffic control configuration.
6 bool "QoS and/or fair queueing"
9 When the kernel has several packets to send out over a network
10 device, it has to decide which ones to send first, which ones to
11 delay, and which ones to drop. This is the job of the queueing
12 disciplines, several different algorithms for how to do this
13 "fairly" have been proposed.
15 If you say N here, you will get the standard packet scheduler, which
16 is a FIFO (first come, first served). If you say Y here, you will be
17 able to choose from among several alternative algorithms which can
18 then be attached to different network devices. This is useful for
19 example if some of your network devices are real time devices that
20 need a certain minimum data flow rate, or if you need to limit the
21 maximum data flow rate for traffic which matches specified criteria.
22 This code is considered to be experimental.
24 To administer these schedulers, you'll need the user-level utilities
25 from the package iproute2+tc at
26 <https://www.kernel.org/pub/linux/utils/net/iproute2/>. That package
27 also contains some documentation; for more, check out
28 <http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2>.
30 This Quality of Service (QoS) support will enable you to use
31 Differentiated Services (diffserv) and Resource Reservation Protocol
32 (RSVP) on your Linux router if you also say Y to the corresponding
33 classifiers below. Documentation and software is at
34 <http://diffserv.sourceforge.net/>.
36 If you say Y here and to "/proc file system" below, you will be able
37 to read status information about packet schedulers from the file
40 The available schedulers are listed in the following questions; you
41 can say Y to as many as you like. If unsure, say N now.
45 comment "Queueing/Scheduling"
48 tristate "Class Based Queueing (CBQ)"
50 Say Y here if you want to use the Class-Based Queueing (CBQ) packet
51 scheduling algorithm. This algorithm classifies the waiting packets
52 into a tree-like hierarchy of classes; the leaves of this tree are
53 in turn scheduled by separate algorithms.
55 See the top of <file:net/sched/sch_cbq.c> for more details.
57 CBQ is a commonly used scheduler, so if you're unsure, you should
58 say Y here. Then say Y to all the queueing algorithms below that you
59 want to use as leaf disciplines.
61 To compile this code as a module, choose M here: the
62 module will be called sch_cbq.
65 tristate "Hierarchical Token Bucket (HTB)"
67 Say Y here if you want to use the Hierarchical Token Buckets (HTB)
68 packet scheduling algorithm. See
69 <http://luxik.cdi.cz/~devik/qos/htb/> for complete manual and
72 HTB is very similar to CBQ regarding its goals however is has
73 different properties and different algorithm.
75 To compile this code as a module, choose M here: the
76 module will be called sch_htb.
79 tristate "Hierarchical Fair Service Curve (HFSC)"
81 Say Y here if you want to use the Hierarchical Fair Service Curve
82 (HFSC) packet scheduling algorithm.
84 To compile this code as a module, choose M here: the
85 module will be called sch_hfsc.
88 tristate "ATM Virtual Circuits (ATM)"
91 Say Y here if you want to use the ATM pseudo-scheduler. This
92 provides a framework for invoking classifiers, which in turn
93 select classes of this queuing discipline. Each class maps
94 the flow(s) it is handling to a given virtual circuit.
96 See the top of <file:net/sched/sch_atm.c> for more details.
98 To compile this code as a module, choose M here: the
99 module will be called sch_atm.
102 tristate "Multi Band Priority Queueing (PRIO)"
104 Say Y here if you want to use an n-band priority queue packet
107 To compile this code as a module, choose M here: the
108 module will be called sch_prio.
110 config NET_SCH_MULTIQ
111 tristate "Hardware Multiqueue-aware Multi Band Queuing (MULTIQ)"
113 Say Y here if you want to use an n-band queue packet scheduler
114 to support devices that have multiple hardware transmit queues.
116 To compile this code as a module, choose M here: the
117 module will be called sch_multiq.
120 tristate "Random Early Detection (RED)"
122 Say Y here if you want to use the Random Early Detection (RED)
123 packet scheduling algorithm.
125 See the top of <file:net/sched/sch_red.c> for more details.
127 To compile this code as a module, choose M here: the
128 module will be called sch_red.
131 tristate "Stochastic Fair Blue (SFB)"
133 Say Y here if you want to use the Stochastic Fair Blue (SFB)
134 packet scheduling algorithm.
136 See the top of <file:net/sched/sch_sfb.c> for more details.
138 To compile this code as a module, choose M here: the
139 module will be called sch_sfb.
142 tristate "Stochastic Fairness Queueing (SFQ)"
144 Say Y here if you want to use the Stochastic Fairness Queueing (SFQ)
145 packet scheduling algorithm.
147 See the top of <file:net/sched/sch_sfq.c> for more details.
149 To compile this code as a module, choose M here: the
150 module will be called sch_sfq.
153 tristate "True Link Equalizer (TEQL)"
155 Say Y here if you want to use the True Link Equalizer (TLE) packet
156 scheduling algorithm. This queueing discipline allows the combination
157 of several physical devices into one virtual device.
159 See the top of <file:net/sched/sch_teql.c> for more details.
161 To compile this code as a module, choose M here: the
162 module will be called sch_teql.
165 tristate "Token Bucket Filter (TBF)"
167 Say Y here if you want to use the Token Bucket Filter (TBF) packet
168 scheduling algorithm.
170 See the top of <file:net/sched/sch_tbf.c> for more details.
172 To compile this code as a module, choose M here: the
173 module will be called sch_tbf.
176 tristate "Credit Based Shaper (CBS)"
178 Say Y here if you want to use the Credit Based Shaper (CBS) packet
179 scheduling algorithm.
181 See the top of <file:net/sched/sch_cbs.c> for more details.
183 To compile this code as a module, choose M here: the
184 module will be called sch_cbs.
187 tristate "Earliest TxTime First (ETF)"
189 Say Y here if you want to use the Earliest TxTime First (ETF) packet
190 scheduling algorithm.
192 See the top of <file:net/sched/sch_etf.c> for more details.
194 To compile this code as a module, choose M here: the
195 module will be called sch_etf.
197 config NET_SCH_TAPRIO
198 tristate "Time Aware Priority (taprio) Scheduler"
200 Say Y here if you want to use the Time Aware Priority (taprio) packet
201 scheduling algorithm.
203 See the top of <file:net/sched/sch_taprio.c> for more details.
205 To compile this code as a module, choose M here: the
206 module will be called sch_taprio.
209 tristate "Generic Random Early Detection (GRED)"
211 Say Y here if you want to use the Generic Random Early Detection
212 (GRED) packet scheduling algorithm for some of your network devices
213 (see the top of <file:net/sched/sch_red.c> for details and
214 references about the algorithm).
216 To compile this code as a module, choose M here: the
217 module will be called sch_gred.
219 config NET_SCH_DSMARK
220 tristate "Differentiated Services marker (DSMARK)"
222 Say Y if you want to schedule packets according to the
223 Differentiated Services architecture proposed in RFC 2475.
224 Technical information on this method, with pointers to associated
225 RFCs, is available at <http://www.gta.ufrj.br/diffserv/>.
227 To compile this code as a module, choose M here: the
228 module will be called sch_dsmark.
231 tristate "Network emulator (NETEM)"
233 Say Y if you want to emulate network delay, loss, and packet
234 re-ordering. This is often useful to simulate networks when
235 testing applications or protocols.
237 To compile this driver as a module, choose M here: the module
238 will be called sch_netem.
243 tristate "Deficit Round Robin scheduler (DRR)"
245 Say Y here if you want to use the Deficit Round Robin (DRR) packet
246 scheduling algorithm.
248 To compile this driver as a module, choose M here: the module
249 will be called sch_drr.
253 config NET_SCH_MQPRIO
254 tristate "Multi-queue priority scheduler (MQPRIO)"
256 Say Y here if you want to use the Multi-queue Priority scheduler.
257 This scheduler allows QOS to be offloaded on NICs that have support
258 for offloading QOS schedulers.
260 To compile this driver as a module, choose M here: the module will
261 be called sch_mqprio.
265 config NET_SCH_SKBPRIO
266 tristate "SKB priority queue scheduler (SKBPRIO)"
268 Say Y here if you want to use the SKB priority queue
269 scheduler. This schedules packets according to skb->priority,
270 which is useful for request packets in DoS mitigation systems such
273 To compile this driver as a module, choose M here: the module will
274 be called sch_skbprio.
279 tristate "CHOose and Keep responsive flow scheduler (CHOKE)"
281 Say Y here if you want to use the CHOKe packet scheduler (CHOose
282 and Keep for responsive flows, CHOose and Kill for unresponsive
283 flows). This is a variation of RED which trys to penalize flows
284 that monopolize the queue.
286 To compile this code as a module, choose M here: the
287 module will be called sch_choke.
290 tristate "Quick Fair Queueing scheduler (QFQ)"
292 Say Y here if you want to use the Quick Fair Queueing Scheduler (QFQ)
293 packet scheduling algorithm.
295 To compile this driver as a module, choose M here: the module
296 will be called sch_qfq.
301 tristate "Controlled Delay AQM (CODEL)"
303 Say Y here if you want to use the Controlled Delay (CODEL)
304 packet scheduling algorithm.
306 To compile this driver as a module, choose M here: the module
307 will be called sch_codel.
311 config NET_SCH_FQ_CODEL
312 tristate "Fair Queue Controlled Delay AQM (FQ_CODEL)"
314 Say Y here if you want to use the FQ Controlled Delay (FQ_CODEL)
315 packet scheduling algorithm.
317 To compile this driver as a module, choose M here: the module
318 will be called sch_fq_codel.
323 tristate "Common Applications Kept Enhanced (CAKE)"
325 Say Y here if you want to use the Common Applications Kept Enhanced
326 (CAKE) queue management algorithm.
328 To compile this driver as a module, choose M here: the module
329 will be called sch_cake.
334 tristate "Fair Queue"
336 Say Y here if you want to use the FQ packet scheduling algorithm.
338 FQ does flow separation, and is able to respect pacing requirements
339 set by TCP stack into sk->sk_pacing_rate (for localy generated
342 To compile this driver as a module, choose M here: the module
343 will be called sch_fq.
348 tristate "Heavy-Hitter Filter (HHF)"
350 Say Y here if you want to use the Heavy-Hitter Filter (HHF)
351 packet scheduling algorithm.
353 To compile this driver as a module, choose M here: the module
354 will be called sch_hhf.
357 tristate "Proportional Integral controller Enhanced (PIE) scheduler"
359 Say Y here if you want to use the Proportional Integral controller
360 Enhanced scheduler packet scheduling algorithm.
361 For more information, please see https://tools.ietf.org/html/rfc8033
363 To compile this driver as a module, choose M here: the module
364 will be called sch_pie.
368 config NET_SCH_INGRESS
369 tristate "Ingress/classifier-action Qdisc"
370 depends on NET_CLS_ACT
374 Say Y here if you want to use classifiers for incoming and/or outgoing
375 packets. This qdisc doesn't do anything else besides running classifiers,
376 which can also have actions attached to them. In case of outgoing packets,
377 classifiers that this qdisc holds are executed in the transmit path
378 before real enqueuing to an egress qdisc happens.
382 To compile this code as a module, choose M here: the module will be
383 called sch_ingress with alias of sch_clsact.
386 tristate "Plug network traffic until release (PLUG)"
389 This queuing discipline allows userspace to plug/unplug a network
390 output queue, using the netlink interface. When it receives an
391 enqueue command it inserts a plug into the outbound queue that
392 causes following packets to enqueue until a dequeue command arrives
393 over netlink, causing the plug to be removed and resuming the normal
396 This module also provides a generic "network output buffering"
397 functionality (aka output commit), wherein upon arrival of a dequeue
398 command, only packets up to the first plug are released for delivery.
399 The Remus HA project uses this module to enable speculative execution
400 of virtual machines by allowing the generated network output to be rolled
403 For more information, please refer to <http://wiki.xenproject.org/wiki/Remus>
405 Say Y here if you are using this kernel for Xen dom0 and
406 want to protect Xen guests with Remus.
408 To compile this code as a module, choose M here: the
409 module will be called sch_plug.
411 menuconfig NET_SCH_DEFAULT
412 bool "Allow override default queue discipline"
414 Support for selection of default queuing discipline.
416 Nearly all users can safely say no here, and the default
417 of pfifo_fast will be used. Many distributions already set
418 the default value via /proc/sys/net/core/default_qdisc.
425 prompt "Default queuing discipline"
426 default DEFAULT_PFIFO_FAST
428 Select the queueing discipline that will be used by default
429 for all network devices.
432 bool "Fair Queue" if NET_SCH_FQ
435 bool "Controlled Delay" if NET_SCH_CODEL
437 config DEFAULT_FQ_CODEL
438 bool "Fair Queue Controlled Delay" if NET_SCH_FQ_CODEL
441 bool "Stochastic Fair Queue" if NET_SCH_SFQ
443 config DEFAULT_PFIFO_FAST
444 bool "Priority FIFO Fast"
447 config DEFAULT_NET_SCH
449 default "pfifo_fast" if DEFAULT_PFIFO_FAST
450 default "fq" if DEFAULT_FQ
451 default "fq_codel" if DEFAULT_FQ_CODEL
452 default "sfq" if DEFAULT_SFQ
456 comment "Classification"
462 tristate "Elementary classification (BASIC)"
465 Say Y here if you want to be able to classify packets using
466 only extended matches and actions.
468 To compile this code as a module, choose M here: the
469 module will be called cls_basic.
471 config NET_CLS_TCINDEX
472 tristate "Traffic-Control Index (TCINDEX)"
475 Say Y here if you want to be able to classify packets based on
476 traffic control indices. You will want this feature if you want
477 to implement Differentiated Services together with DSMARK.
479 To compile this code as a module, choose M here: the
480 module will be called cls_tcindex.
482 config NET_CLS_ROUTE4
483 tristate "Routing decision (ROUTE)"
485 select IP_ROUTE_CLASSID
488 If you say Y here, you will be able to classify packets
489 according to the route table entry they matched.
491 To compile this code as a module, choose M here: the
492 module will be called cls_route.
495 tristate "Netfilter mark (FW)"
498 If you say Y here, you will be able to classify packets
499 according to netfilter/firewall marks.
501 To compile this code as a module, choose M here: the
502 module will be called cls_fw.
505 tristate "Universal 32bit comparisons w/ hashing (U32)"
508 Say Y here to be able to classify packets using a universal
509 32bit pieces based comparison scheme.
511 To compile this code as a module, choose M here: the
512 module will be called cls_u32.
515 bool "Performance counters support"
516 depends on NET_CLS_U32
518 Say Y here to make u32 gather additional statistics useful for
519 fine tuning u32 classifiers.
522 bool "Netfilter marks support"
523 depends on NET_CLS_U32
525 Say Y here to be able to use netfilter marks as u32 key.
528 tristate "IPv4 Resource Reservation Protocol (RSVP)"
531 The Resource Reservation Protocol (RSVP) permits end systems to
532 request a minimum and maximum data flow rate for a connection; this
533 is important for real time data such as streaming sound or video.
535 Say Y here if you want to be able to classify outgoing packets based
536 on their RSVP requests.
538 To compile this code as a module, choose M here: the
539 module will be called cls_rsvp.
542 tristate "IPv6 Resource Reservation Protocol (RSVP6)"
545 The Resource Reservation Protocol (RSVP) permits end systems to
546 request a minimum and maximum data flow rate for a connection; this
547 is important for real time data such as streaming sound or video.
549 Say Y here if you want to be able to classify outgoing packets based
550 on their RSVP requests and you are using the IPv6 protocol.
552 To compile this code as a module, choose M here: the
553 module will be called cls_rsvp6.
556 tristate "Flow classifier"
559 If you say Y here, you will be able to classify packets based on
560 a configurable combination of packet keys. This is mostly useful
561 in combination with SFQ.
563 To compile this code as a module, choose M here: the
564 module will be called cls_flow.
566 config NET_CLS_CGROUP
567 tristate "Control Group Classifier"
569 select CGROUP_NET_CLASSID
572 Say Y here if you want to classify packets based on the control
573 cgroup of their process.
575 To compile this code as a module, choose M here: the
576 module will be called cls_cgroup.
579 tristate "BPF-based classifier"
582 If you say Y here, you will be able to classify packets based on
583 programmable BPF (JIT'ed) filters as an alternative to ematches.
585 To compile this code as a module, choose M here: the module will
588 config NET_CLS_FLOWER
589 tristate "Flower classifier"
592 If you say Y here, you will be able to classify packets based on
593 a configurable combination of packet keys and masks.
595 To compile this code as a module, choose M here: the module will
596 be called cls_flower.
598 config NET_CLS_MATCHALL
599 tristate "Match-all classifier"
602 If you say Y here, you will be able to classify packets based on
603 nothing. Every packet will match.
605 To compile this code as a module, choose M here: the module will
606 be called cls_matchall.
609 bool "Extended Matches"
612 Say Y here if you want to use extended matches on top of classifiers
613 and select the extended matches below.
615 Extended matches are small classification helpers not worth writing
616 a separate classifier for.
618 A recent version of the iproute2 package is required to use
621 config NET_EMATCH_STACK
623 depends on NET_EMATCH
626 Size of the local stack variable used while evaluating the tree of
627 ematches. Limits the depth of the tree, i.e. the number of
628 encapsulated precedences. Every level requires 4 bytes of additional
631 config NET_EMATCH_CMP
632 tristate "Simple packet data comparison"
633 depends on NET_EMATCH
635 Say Y here if you want to be able to classify packets based on
636 simple packet data comparisons for 8, 16, and 32bit values.
638 To compile this code as a module, choose M here: the
639 module will be called em_cmp.
641 config NET_EMATCH_NBYTE
642 tristate "Multi byte comparison"
643 depends on NET_EMATCH
645 Say Y here if you want to be able to classify packets based on
646 multiple byte comparisons mainly useful for IPv6 address comparisons.
648 To compile this code as a module, choose M here: the
649 module will be called em_nbyte.
651 config NET_EMATCH_U32
653 depends on NET_EMATCH
655 Say Y here if you want to be able to classify packets using
656 the famous u32 key in combination with logic relations.
658 To compile this code as a module, choose M here: the
659 module will be called em_u32.
661 config NET_EMATCH_META
663 depends on NET_EMATCH
665 Say Y here if you want to be able to classify packets based on
666 metadata such as load average, netfilter attributes, socket
667 attributes and routing decisions.
669 To compile this code as a module, choose M here: the
670 module will be called em_meta.
672 config NET_EMATCH_TEXT
673 tristate "Textsearch"
674 depends on NET_EMATCH
676 select TEXTSEARCH_KMP
678 select TEXTSEARCH_FSM
680 Say Y here if you want to be able to classify packets based on
681 textsearch comparisons.
683 To compile this code as a module, choose M here: the
684 module will be called em_text.
686 config NET_EMATCH_CANID
687 tristate "CAN Identifier"
688 depends on NET_EMATCH && (CAN=y || CAN=m)
690 Say Y here if you want to be able to classify CAN frames based
693 To compile this code as a module, choose M here: the
694 module will be called em_canid.
696 config NET_EMATCH_IPSET
698 depends on NET_EMATCH && IP_SET
700 Say Y here if you want to be able to classify packets based on
703 To compile this code as a module, choose M here: the
704 module will be called em_ipset.
706 config NET_EMATCH_IPT
707 tristate "IPtables Matches"
708 depends on NET_EMATCH && NETFILTER && NETFILTER_XTABLES
710 Say Y here to be able to classify packets based on iptables
712 Current supported match is "policy" which allows packet classification
713 based on IPsec policy that was used during decapsulation
715 To compile this code as a module, choose M here: the
716 module will be called em_ipt.
722 Say Y here if you want to use traffic control actions. Actions
723 get attached to classifiers and are invoked after a successful
724 classification. They are used to overwrite the classification
725 result, instantly drop or redirect packets, etc.
727 A recent version of the iproute2 package is required to use
730 config NET_ACT_POLICE
731 tristate "Traffic Policing"
732 depends on NET_CLS_ACT
734 Say Y here if you want to do traffic policing, i.e. strict
735 bandwidth limiting. This action replaces the existing policing
738 To compile this code as a module, choose M here: the
739 module will be called act_police.
742 tristate "Generic actions"
743 depends on NET_CLS_ACT
745 Say Y here to take generic actions such as dropping and
748 To compile this code as a module, choose M here: the
749 module will be called act_gact.
752 bool "Probability support"
753 depends on NET_ACT_GACT
755 Say Y here to use the generic action randomly or deterministically.
757 config NET_ACT_MIRRED
758 tristate "Redirecting and Mirroring"
759 depends on NET_CLS_ACT
761 Say Y here to allow packets to be mirrored or redirected to
764 To compile this code as a module, choose M here: the
765 module will be called act_mirred.
767 config NET_ACT_SAMPLE
768 tristate "Traffic Sampling"
769 depends on NET_CLS_ACT
772 Say Y here to allow packet sampling tc action. The packet sample
773 action consists of statistically choosing packets and sampling
774 them using the psample module.
776 To compile this code as a module, choose M here: the
777 module will be called act_sample.
780 tristate "IPtables targets"
781 depends on NET_CLS_ACT && NETFILTER && IP_NF_IPTABLES
783 Say Y here to be able to invoke iptables targets after successful
786 To compile this code as a module, choose M here: the
787 module will be called act_ipt.
790 tristate "Stateless NAT"
791 depends on NET_CLS_ACT
793 Say Y here to do stateless NAT on IPv4 packets. You should use
794 netfilter for NAT unless you know what you are doing.
796 To compile this code as a module, choose M here: the
797 module will be called act_nat.
800 tristate "Packet Editing"
801 depends on NET_CLS_ACT
803 Say Y here if you want to mangle the content of packets.
805 To compile this code as a module, choose M here: the
806 module will be called act_pedit.
809 tristate "Simple Example (Debug)"
810 depends on NET_CLS_ACT
812 Say Y here to add a simple action for demonstration purposes.
813 It is meant as an example and for debugging purposes. It will
814 print a configured policy string followed by the packet count
815 to the console for every packet that passes by.
819 To compile this code as a module, choose M here: the
820 module will be called act_simple.
822 config NET_ACT_SKBEDIT
823 tristate "SKB Editing"
824 depends on NET_CLS_ACT
826 Say Y here to change skb priority or queue_mapping settings.
830 To compile this code as a module, choose M here: the
831 module will be called act_skbedit.
834 tristate "Checksum Updating"
835 depends on NET_CLS_ACT && INET
838 Say Y here to update some common checksum after some direct
841 To compile this code as a module, choose M here: the
842 module will be called act_csum.
845 tristate "Vlan manipulation"
846 depends on NET_CLS_ACT
848 Say Y here to push or pop vlan headers.
852 To compile this code as a module, choose M here: the
853 module will be called act_vlan.
856 tristate "BPF based action"
857 depends on NET_CLS_ACT
859 Say Y here to execute BPF code on packets. The BPF code will decide
860 if the packet should be dropped or not.
864 To compile this code as a module, choose M here: the
865 module will be called act_bpf.
867 config NET_ACT_CONNMARK
868 tristate "Netfilter Connection Mark Retriever"
869 depends on NET_CLS_ACT && NETFILTER && IP_NF_IPTABLES
870 depends on NF_CONNTRACK && NF_CONNTRACK_MARK
872 Say Y here to allow retrieving of conn mark
876 To compile this code as a module, choose M here: the
877 module will be called act_connmark.
879 config NET_ACT_SKBMOD
880 tristate "skb data modification action"
881 depends on NET_CLS_ACT
883 Say Y here to allow modification of skb data
887 To compile this code as a module, choose M here: the
888 module will be called act_skbmod.
891 tristate "Inter-FE action based on IETF ForCES InterFE LFB"
892 depends on NET_CLS_ACT
895 Say Y here to allow for sourcing and terminating metadata
896 For details refer to netdev01 paper:
897 "Distributing Linux Traffic Control Classifier-Action Subsystem"
898 Authors: Jamal Hadi Salim and Damascene M. Joachimpillai
900 To compile this code as a module, choose M here: the
901 module will be called act_ife.
903 config NET_ACT_TUNNEL_KEY
904 tristate "IP tunnel metadata manipulation"
905 depends on NET_CLS_ACT
907 Say Y here to set/release ip tunnel metadata.
911 To compile this code as a module, choose M here: the
912 module will be called act_tunnel_key.
914 config NET_IFE_SKBMARK
915 tristate "Support to encoding decoding skb mark on IFE action"
916 depends on NET_ACT_IFE
918 config NET_IFE_SKBPRIO
919 tristate "Support to encoding decoding skb prio on IFE action"
920 depends on NET_ACT_IFE
922 config NET_IFE_SKBTCINDEX
923 tristate "Support to encoding decoding skb tcindex on IFE action"
924 depends on NET_ACT_IFE
927 bool "Incoming device classification"
928 depends on NET_CLS_U32 || NET_CLS_FW
930 Say Y here to extend the u32 and fw classifier to support
931 classification based on the incoming device. This option is
932 likely to disappear in favour of the metadata ematch.