![Herbert Xu](/assets/img/avatar_default.png)
Stateless NAT is useful in controlled environments where restrictions are placed on through traffic such that we don't need connection tracking to correctly NAT protocol-specific data. In particular, this is of interest when the number of flows or the number of addresses being NATed is large, or if connection tracking information has to be replicated and where it is not practical to do so. Previously we had stateless NAT functionality which was integrated into the IPv4 routing subsystem. This was a great solution as long as the NAT worked on a subnet to subnet basis such that the number of NAT rules was relatively small. The reason is that for SNAT the routing based system had to perform a linear scan through the rules. If the number of rules is large then major renovations would have take place in the routing subsystem to make this practical. For the time being, the least intrusive way of achieving this is to use the u32 classifier written by Alexey Kuznetsov along with the actions infrastructure implemented by Jamal Hadi Salim. The following patch is an attempt at this problem by creating a new nat action that can be invoked from u32 hash tables which would allow large number of stateless NAT rules that can be used/updated in constant time. The actual NAT code is mostly based on the previous stateless NAT code written by Alexey. In future we might be able to utilise the protocol NAT code from netfilter to improve support for other protocols. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
504 lines
16 KiB
Text
504 lines
16 KiB
Text
#
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# Traffic control configuration.
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#
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menu "QoS and/or fair queueing"
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config NET_SCHED
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bool "QoS and/or fair queueing"
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select NET_SCH_FIFO
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---help---
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When the kernel has several packets to send out over a network
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device, it has to decide which ones to send first, which ones to
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delay, and which ones to drop. This is the job of the queueing
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disciplines, several different algorithms for how to do this
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"fairly" have been proposed.
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If you say N here, you will get the standard packet scheduler, which
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is a FIFO (first come, first served). If you say Y here, you will be
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able to choose from among several alternative algorithms which can
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then be attached to different network devices. This is useful for
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example if some of your network devices are real time devices that
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need a certain minimum data flow rate, or if you need to limit the
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maximum data flow rate for traffic which matches specified criteria.
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This code is considered to be experimental.
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To administer these schedulers, you'll need the user-level utilities
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from the package iproute2+tc at <ftp://ftp.tux.org/pub/net/ip-routing/>.
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That package also contains some documentation; for more, check out
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<http://linux-net.osdl.org/index.php/Iproute2>.
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This Quality of Service (QoS) support will enable you to use
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Differentiated Services (diffserv) and Resource Reservation Protocol
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(RSVP) on your Linux router if you also say Y to the corresponding
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classifiers below. Documentation and software is at
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<http://diffserv.sourceforge.net/>.
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If you say Y here and to "/proc file system" below, you will be able
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to read status information about packet schedulers from the file
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/proc/net/psched.
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The available schedulers are listed in the following questions; you
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can say Y to as many as you like. If unsure, say N now.
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config NET_SCH_FIFO
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bool
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if NET_SCHED
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comment "Queueing/Scheduling"
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config NET_SCH_CBQ
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tristate "Class Based Queueing (CBQ)"
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---help---
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Say Y here if you want to use the Class-Based Queueing (CBQ) packet
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scheduling algorithm. This algorithm classifies the waiting packets
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into a tree-like hierarchy of classes; the leaves of this tree are
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in turn scheduled by separate algorithms.
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See the top of <file:net/sched/sch_cbq.c> for more details.
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CBQ is a commonly used scheduler, so if you're unsure, you should
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say Y here. Then say Y to all the queueing algorithms below that you
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want to use as leaf disciplines.
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To compile this code as a module, choose M here: the
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module will be called sch_cbq.
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config NET_SCH_HTB
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tristate "Hierarchical Token Bucket (HTB)"
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---help---
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Say Y here if you want to use the Hierarchical Token Buckets (HTB)
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packet scheduling algorithm. See
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<http://luxik.cdi.cz/~devik/qos/htb/> for complete manual and
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in-depth articles.
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HTB is very similar to CBQ regarding its goals however is has
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different properties and different algorithm.
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To compile this code as a module, choose M here: the
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module will be called sch_htb.
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config NET_SCH_HFSC
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tristate "Hierarchical Fair Service Curve (HFSC)"
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---help---
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Say Y here if you want to use the Hierarchical Fair Service Curve
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(HFSC) packet scheduling algorithm.
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To compile this code as a module, choose M here: the
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module will be called sch_hfsc.
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config NET_SCH_ATM
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tristate "ATM Virtual Circuits (ATM)"
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depends on ATM
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---help---
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Say Y here if you want to use the ATM pseudo-scheduler. This
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provides a framework for invoking classifiers, which in turn
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select classes of this queuing discipline. Each class maps
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the flow(s) it is handling to a given virtual circuit.
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See the top of <file:net/sched/sch_atm.c> for more details.
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To compile this code as a module, choose M here: the
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module will be called sch_atm.
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config NET_SCH_PRIO
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tristate "Multi Band Priority Queueing (PRIO)"
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---help---
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Say Y here if you want to use an n-band priority queue packet
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scheduler.
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To compile this code as a module, choose M here: the
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module will be called sch_prio.
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config NET_SCH_RR
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tristate "Multi Band Round Robin Queuing (RR)"
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select NET_SCH_PRIO
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---help---
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Say Y here if you want to use an n-band round robin packet
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scheduler.
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The module uses sch_prio for its framework and is aliased as
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sch_rr, so it will load sch_prio, although it is referred
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to using sch_rr.
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config NET_SCH_RED
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tristate "Random Early Detection (RED)"
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---help---
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Say Y here if you want to use the Random Early Detection (RED)
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packet scheduling algorithm.
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See the top of <file:net/sched/sch_red.c> for more details.
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To compile this code as a module, choose M here: the
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module will be called sch_red.
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config NET_SCH_SFQ
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tristate "Stochastic Fairness Queueing (SFQ)"
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---help---
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Say Y here if you want to use the Stochastic Fairness Queueing (SFQ)
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packet scheduling algorithm.
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See the top of <file:net/sched/sch_sfq.c> for more details.
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To compile this code as a module, choose M here: the
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module will be called sch_sfq.
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config NET_SCH_TEQL
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tristate "True Link Equalizer (TEQL)"
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---help---
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Say Y here if you want to use the True Link Equalizer (TLE) packet
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scheduling algorithm. This queueing discipline allows the combination
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of several physical devices into one virtual device.
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See the top of <file:net/sched/sch_teql.c> for more details.
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To compile this code as a module, choose M here: the
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module will be called sch_teql.
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config NET_SCH_TBF
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tristate "Token Bucket Filter (TBF)"
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---help---
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Say Y here if you want to use the Token Bucket Filter (TBF) packet
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scheduling algorithm.
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See the top of <file:net/sched/sch_tbf.c> for more details.
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To compile this code as a module, choose M here: the
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module will be called sch_tbf.
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config NET_SCH_GRED
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tristate "Generic Random Early Detection (GRED)"
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---help---
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Say Y here if you want to use the Generic Random Early Detection
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(GRED) packet scheduling algorithm for some of your network devices
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(see the top of <file:net/sched/sch_red.c> for details and
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references about the algorithm).
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To compile this code as a module, choose M here: the
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module will be called sch_gred.
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config NET_SCH_DSMARK
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tristate "Differentiated Services marker (DSMARK)"
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---help---
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Say Y if you want to schedule packets according to the
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Differentiated Services architecture proposed in RFC 2475.
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Technical information on this method, with pointers to associated
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RFCs, is available at <http://www.gta.ufrj.br/diffserv/>.
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To compile this code as a module, choose M here: the
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module will be called sch_dsmark.
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config NET_SCH_NETEM
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tristate "Network emulator (NETEM)"
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---help---
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Say Y if you want to emulate network delay, loss, and packet
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re-ordering. This is often useful to simulate networks when
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testing applications or protocols.
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To compile this driver as a module, choose M here: the module
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will be called sch_netem.
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If unsure, say N.
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config NET_SCH_INGRESS
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tristate "Ingress Qdisc"
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---help---
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Say Y here if you want to use classifiers for incoming packets.
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If unsure, say Y.
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To compile this code as a module, choose M here: the
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module will be called sch_ingress.
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comment "Classification"
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config NET_CLS
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boolean
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config NET_CLS_BASIC
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tristate "Elementary classification (BASIC)"
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select NET_CLS
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---help---
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Say Y here if you want to be able to classify packets using
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only extended matches and actions.
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To compile this code as a module, choose M here: the
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module will be called cls_basic.
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config NET_CLS_TCINDEX
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tristate "Traffic-Control Index (TCINDEX)"
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select NET_CLS
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---help---
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Say Y here if you want to be able to classify packets based on
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traffic control indices. You will want this feature if you want
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to implement Differentiated Services together with DSMARK.
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To compile this code as a module, choose M here: the
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module will be called cls_tcindex.
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config NET_CLS_ROUTE4
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tristate "Routing decision (ROUTE)"
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select NET_CLS_ROUTE
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select NET_CLS
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---help---
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If you say Y here, you will be able to classify packets
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according to the route table entry they matched.
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To compile this code as a module, choose M here: the
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module will be called cls_route.
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config NET_CLS_ROUTE
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bool
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config NET_CLS_FW
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tristate "Netfilter mark (FW)"
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select NET_CLS
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---help---
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If you say Y here, you will be able to classify packets
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according to netfilter/firewall marks.
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To compile this code as a module, choose M here: the
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module will be called cls_fw.
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config NET_CLS_U32
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tristate "Universal 32bit comparisons w/ hashing (U32)"
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select NET_CLS
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---help---
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Say Y here to be able to classify packets using a universal
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32bit pieces based comparison scheme.
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To compile this code as a module, choose M here: the
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module will be called cls_u32.
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config CLS_U32_PERF
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bool "Performance counters support"
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depends on NET_CLS_U32
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---help---
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Say Y here to make u32 gather additional statistics useful for
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fine tuning u32 classifiers.
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config CLS_U32_MARK
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bool "Netfilter marks support"
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depends on NET_CLS_U32
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---help---
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Say Y here to be able to use netfilter marks as u32 key.
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config NET_CLS_RSVP
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tristate "IPv4 Resource Reservation Protocol (RSVP)"
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select NET_CLS
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---help---
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The Resource Reservation Protocol (RSVP) permits end systems to
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request a minimum and maximum data flow rate for a connection; this
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is important for real time data such as streaming sound or video.
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Say Y here if you want to be able to classify outgoing packets based
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on their RSVP requests.
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To compile this code as a module, choose M here: the
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module will be called cls_rsvp.
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config NET_CLS_RSVP6
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tristate "IPv6 Resource Reservation Protocol (RSVP6)"
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select NET_CLS
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---help---
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The Resource Reservation Protocol (RSVP) permits end systems to
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request a minimum and maximum data flow rate for a connection; this
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is important for real time data such as streaming sound or video.
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Say Y here if you want to be able to classify outgoing packets based
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on their RSVP requests and you are using the IPv6 protocol.
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To compile this code as a module, choose M here: the
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module will be called cls_rsvp6.
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config NET_EMATCH
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bool "Extended Matches"
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select NET_CLS
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---help---
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Say Y here if you want to use extended matches on top of classifiers
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and select the extended matches below.
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Extended matches are small classification helpers not worth writing
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a separate classifier for.
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A recent version of the iproute2 package is required to use
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extended matches.
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config NET_EMATCH_STACK
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int "Stack size"
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depends on NET_EMATCH
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default "32"
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---help---
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Size of the local stack variable used while evaluating the tree of
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ematches. Limits the depth of the tree, i.e. the number of
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encapsulated precedences. Every level requires 4 bytes of additional
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stack space.
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config NET_EMATCH_CMP
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tristate "Simple packet data comparison"
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depends on NET_EMATCH
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---help---
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Say Y here if you want to be able to classify packets based on
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simple packet data comparisons for 8, 16, and 32bit values.
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To compile this code as a module, choose M here: the
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module will be called em_cmp.
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config NET_EMATCH_NBYTE
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tristate "Multi byte comparison"
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depends on NET_EMATCH
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---help---
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Say Y here if you want to be able to classify packets based on
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multiple byte comparisons mainly useful for IPv6 address comparisons.
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To compile this code as a module, choose M here: the
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module will be called em_nbyte.
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config NET_EMATCH_U32
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tristate "U32 key"
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depends on NET_EMATCH
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---help---
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Say Y here if you want to be able to classify packets using
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the famous u32 key in combination with logic relations.
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To compile this code as a module, choose M here: the
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module will be called em_u32.
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config NET_EMATCH_META
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tristate "Metadata"
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depends on NET_EMATCH
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---help---
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Say Y here if you want to be able to classify packets based on
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metadata such as load average, netfilter attributes, socket
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attributes and routing decisions.
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To compile this code as a module, choose M here: the
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module will be called em_meta.
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config NET_EMATCH_TEXT
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tristate "Textsearch"
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depends on NET_EMATCH
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select TEXTSEARCH
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select TEXTSEARCH_KMP
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select TEXTSEARCH_BM
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select TEXTSEARCH_FSM
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---help---
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Say Y here if you want to be able to classify packets based on
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textsearch comparisons.
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To compile this code as a module, choose M here: the
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module will be called em_text.
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config NET_CLS_ACT
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bool "Actions"
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---help---
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Say Y here if you want to use traffic control actions. Actions
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get attached to classifiers and are invoked after a successful
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classification. They are used to overwrite the classification
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result, instantly drop or redirect packets, etc.
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A recent version of the iproute2 package is required to use
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extended matches.
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config NET_ACT_POLICE
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tristate "Traffic Policing"
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depends on NET_CLS_ACT
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---help---
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Say Y here if you want to do traffic policing, i.e. strict
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bandwidth limiting. This action replaces the existing policing
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module.
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To compile this code as a module, choose M here: the
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module will be called police.
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config NET_ACT_GACT
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tristate "Generic actions"
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depends on NET_CLS_ACT
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---help---
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Say Y here to take generic actions such as dropping and
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accepting packets.
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To compile this code as a module, choose M here: the
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module will be called gact.
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config GACT_PROB
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bool "Probability support"
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depends on NET_ACT_GACT
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---help---
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Say Y here to use the generic action randomly or deterministically.
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config NET_ACT_MIRRED
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tristate "Redirecting and Mirroring"
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depends on NET_CLS_ACT
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---help---
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Say Y here to allow packets to be mirrored or redirected to
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other devices.
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To compile this code as a module, choose M here: the
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module will be called mirred.
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config NET_ACT_IPT
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tristate "IPtables targets"
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depends on NET_CLS_ACT && NETFILTER && IP_NF_IPTABLES
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---help---
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Say Y here to be able to invoke iptables targets after successful
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classification.
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To compile this code as a module, choose M here: the
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module will be called ipt.
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config NET_ACT_NAT
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tristate "Stateless NAT"
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depends on NET_CLS_ACT
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select NETFILTER
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---help---
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Say Y here to do stateless NAT on IPv4 packets. You should use
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netfilter for NAT unless you know what you are doing.
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To compile this code as a module, choose M here: the
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module will be called nat.
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config NET_ACT_PEDIT
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tristate "Packet Editing"
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depends on NET_CLS_ACT
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---help---
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Say Y here if you want to mangle the content of packets.
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To compile this code as a module, choose M here: the
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module will be called pedit.
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config NET_ACT_SIMP
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tristate "Simple Example (Debug)"
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depends on NET_CLS_ACT
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---help---
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Say Y here to add a simple action for demonstration purposes.
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It is meant as an example and for debugging purposes. It will
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print a configured policy string followed by the packet count
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to the console for every packet that passes by.
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If unsure, say N.
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To compile this code as a module, choose M here: the
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module will be called simple.
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config NET_CLS_POLICE
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bool "Traffic Policing (obsolete)"
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select NET_CLS_ACT
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select NET_ACT_POLICE
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---help---
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Say Y here if you want to do traffic policing, i.e. strict
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bandwidth limiting. This option is obsolete and just selects
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the option replacing it. It will be removed in the future.
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config NET_CLS_IND
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bool "Incoming device classification"
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depends on NET_CLS_U32 || NET_CLS_FW
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---help---
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Say Y here to extend the u32 and fw classifier to support
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classification based on the incoming device. This option is
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likely to disappear in favour of the metadata ematch.
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endif # NET_SCHED
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endmenu
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