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 $NetBSD: bpfjit.4,v 1.3 2024/09/07 20:33:53 rillig Exp $

 Copyright (c) 2014 Alexander Nasonov.
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.Dd July 24, 2014
.Dt BPFJIT 4
.Os
.Sh NAME
.Nm bpfjit
.Nd Just-In-Time compiler for Berkeley Packet Filter
.Sh SYNOPSIS
.Cd "options BPFJIT"
.Cd "options SLJIT"
.Sh DESCRIPTION
The
.Nm
kernel interface adds
.Sy Just-In-Time
compilation of filter programs sent to a
.Xr bpf 4
device.
Instead of being interpreted for every packet,
these filter programs are compiled into native code
and the code is being executed for every packet.

p
The implementation of
.Nm
is based on the
.Sy Stack-Less Just-In-Time
library, or
.Nm sljit
for short.
The library supports multiple platforms including
l -bullet -offset indent -compact t AMD-x86 64
t ARM 32 (ARM-v5, ARM-v7 and Thumb2 instruction sets)
t Intel-x86 32
t MIPS 32 (III, R1)
t MIPS 64 (III, R1)
t PowerPC 32
t PowerPC 64
t SPARC 32
.El

p
.Nm
supports all architectures listed above.

p
.Nm
is also available as a module in modular kernels.
.Sh SYSCTLS
The following sysctl is available when
.Nm
is enabled:
l -tag -width "XnetXbpfXjitXX" t Li net.bpf.jit Toggle
.Sy Just-In-Time
compilation of new filter programs.
Changing a value of this sysctl doesn't affect
existing filter programs.
.El
.Sh SEE ALSO
.Xr bpf 4 ,
.Xr modload 8

p
.Lk https://zherczeg.github.io/sljit/ sljit library
.Sh HISTORY
The
.Nm
interface first appeared in
.Nx 7.0 .
.Sh AUTHORS
The
.Nm
code was written by
.An Alexander Nasonov Aq Mt alnsn (at] NetBSD.org .

p
The
.Nm sljit
library was written by
.An Zoltan Herczeg Aq Mt hzmester (at] freemail.hu .