FreeBSD/Linux Kernel Cross Reference
sys/net/bpf_jitter.h
1 /*-
2 * Copyright (C) 2002-2003 NetGroup, Politecnico di Torino (Italy)
3 * Copyright (C) 2005-2008 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 * $FreeBSD$
32 */
33
34 #ifndef _NET_BPF_JITTER_H_
35 #define _NET_BPF_JITTER_H_
36
37 #ifdef _KERNEL
38 MALLOC_DECLARE(M_BPFJIT);
39 #endif
40
41 extern int bpf_jitter_enable;
42
43 /*
44 * Prototype of a filtering function created by the jitter.
45 *
46 * The syntax and the meaning of the parameters is analogous to the one of
47 * bpf_filter(). Notice that the filter is not among the parameters because
48 * it is hardwired in the function.
49 */
50 typedef u_int (*bpf_filter_func)(u_char *, u_int, u_int);
51
52 /* Structure describing a native filtering program created by the jitter. */
53 typedef struct bpf_jit_filter {
54 /* The native filtering binary, in the form of a bpf_filter_func. */
55 bpf_filter_func func;
56
57 int mem[BPF_MEMWORDS]; /* Scratch memory */
58 } bpf_jit_filter;
59
60 /*
61 * BPF jitter, builds a machine function from a BPF program.
62 *
63 * param fp The BPF pseudo-assembly filter that will be translated
64 * into native code.
65 * param nins Number of instructions of the input filter.
66 * return The bpf_jit_filter structure containing the native filtering
67 * binary.
68 *
69 * bpf_jitter allocates the buffers for the new native filter and
70 * then translates the program pointed by fp calling bpf_jit_compile().
71 */
72 bpf_jit_filter *bpf_jitter(struct bpf_insn *fp, int nins);
73
74 /*
75 * Deletes a filtering function that was previously created by bpf_jitter().
76 *
77 * param filter The filter to destroy.
78 *
79 * This function frees the variuos buffers (code, memory, etc.) associated
80 * with a filtering function.
81 */
82 void bpf_destroy_jit_filter(bpf_jit_filter *filter);
83
84 #endif /* _NET_BPF_JITTER_H_ */
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