freebsd-skq/sys/net/bpf_jitter.h
jkim 052bc52af7 - Allocate scratch memory on stack instead of pre-allocating it with
the filter as we do from bpf_filter()[1].
- Revert experimental use of contigmalloc(9)/contigfree(9).  It has no
performance benefit over malloc(9)/free(9)[2].

Requested by:	rwatson[1]
Pointed out by:	rwatson, jhb, alc[2]
2009-11-20 18:49:20 +00:00

84 lines
3.1 KiB
C

/*-
* Copyright (C) 2002-2003 NetGroup, Politecnico di Torino (Italy)
* Copyright (C) 2005-2009 Jung-uk Kim <jkim@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Politecnico di Torino nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _NET_BPF_JITTER_H_
#define _NET_BPF_JITTER_H_
#ifdef _KERNEL
MALLOC_DECLARE(M_BPFJIT);
#endif
extern int bpf_jitter_enable;
/*
* Prototype of a filtering function created by the jitter.
*
* The syntax and the meaning of the parameters is analogous to the one of
* bpf_filter(). Notice that the filter is not among the parameters because
* it is hardwired in the function.
*/
typedef u_int (*bpf_filter_func)(u_char *, u_int, u_int);
/* Structure describing a native filtering program created by the jitter. */
typedef struct bpf_jit_filter {
/* The native filtering binary, in the form of a bpf_filter_func. */
bpf_filter_func func;
size_t size;
} bpf_jit_filter;
/*
* BPF jitter, builds a machine function from a BPF program.
*
* param fp The BPF pseudo-assembly filter that will be translated
* into native code.
* param nins Number of instructions of the input filter.
* return The bpf_jit_filter structure containing the native filtering
* binary.
*
* bpf_jitter allocates the buffers for the new native filter and
* then translates the program pointed by fp calling bpf_jit_compile().
*/
bpf_jit_filter *bpf_jitter(struct bpf_insn *fp, int nins);
/*
* Deletes a filtering function that was previously created by bpf_jitter().
*
* param filter The filter to destroy.
*
* This function frees the variuos buffers (code, memory, etc.) associated
* with a filtering function.
*/
void bpf_destroy_jit_filter(bpf_jit_filter *filter);
#endif /* _NET_BPF_JITTER_H_ */