bpf_jitter.h revision 153213 
1/*-
2 * Copyright (c) 2002 - 2003 NetGroup, Politecnico di Torino (Italy)
3 * Copyright (c) 2005 Jung-uk Kim <jkim@FreeBSD.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the Politecnico di Torino nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS intERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * $FreeBSD: head/sys/net/bpf_jitter.h 153213 2005-12-07 21:30:47Z jkim $
32 */
33
34#ifndef _NET_BPF_JITTER_H_
35#define _NET_BPF_JITTER_H_
36
37MALLOC_DECLARE(M_BPFJIT);
38
39extern int bpf_jitter_enable;
40
41/*
42 * Prototype of a filtering function created by the jitter.
43 *
44 * The syntax and the meaning of the parameters is analogous to the one of
45 * bpf_filter(). Notice that the filter is not among the parameters because
46 * it is hardwired in the function.
47 */
48typedef u_int (*bpf_filter_func)(u_char *, u_int, u_int);
49
50/* Structure describing a native filtering program created by the jitter. */
51typedef struct bpf_jit_filter {
52	/* The native filtering binary, in the form of a bpf_filter_func. */
53	bpf_filter_func	func;
54
55	int		*mem;
56} bpf_jit_filter;
57
58/*
59 * BPF jitter, builds a machine function from a BPF program.
60 *
61 * param fp	The BPF pseudo-assembly filter that will be translated
62 *		into native code.
63 * param nins	Number of instructions of the input filter.
64 * return	The bpf_jit_filter structure containing the native filtering
65 *		binary.
66 *
67 * bpf_jitter allocates the buffers for the new native filter and
68 * then translates the program pointed by fp calling bpf_jit_compile().
69 */
70bpf_jit_filter	*bpf_jitter(struct bpf_insn *fp, int nins);
71
72/*
73 * Deletes a filtering function that was previously created by bpf_jitter().
74 *
75 * param filter	The filter to destroy.
76 *
77 * This function frees the variuos buffers (code, memory, etc.) associated
78 * with a filtering function.
79 */
80void		bpf_destroy_jit_filter(bpf_jit_filter *filter);
81
82#endif	/* _NET_BPF_JITTER_H_ */
83