bpf_jitter.c 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
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/sys/net/bpf_jitter.c 153213 2005-12-07 21:30:47Z jkim $");
34
35#include "opt_bpf.h"
36
37#include <sys/param.h>
38#include <sys/kernel.h>
39#include <sys/malloc.h>
40#include <sys/mbuf.h>
41#include <sys/sysctl.h>
42
43#include <net/bpf.h>
44#include <net/bpf_jitter.h>
45
46MALLOC_DEFINE(M_BPFJIT, "BPF_JIT", "BPF JIT compiler");
47
48bpf_filter_func	bpf_jit_compile(struct bpf_insn *, u_int, int *);
49
50SYSCTL_NODE(_net, OID_AUTO, bpf_jitter, CTLFLAG_RW, 0, "BPF JIT compiler");
51int bpf_jitter_enable = 1;
52SYSCTL_INT(_net_bpf_jitter, OID_AUTO, enable, CTLFLAG_RW,
53    &bpf_jitter_enable, 0, "enable BPF JIT compiler");
54
55bpf_jit_filter *
56bpf_jitter(struct bpf_insn *fp, int nins)
57{
58	bpf_jit_filter *filter;
59
60	/* Allocate the filter structure */
61	filter = (struct bpf_jit_filter *)malloc(sizeof(struct bpf_jit_filter),
62	    M_BPFJIT, M_NOWAIT);
63	if (filter == NULL)
64		return NULL;
65
66	/* Allocate the filter's memory */
67	filter->mem = (int *)malloc(BPF_MEMWORDS * sizeof(int),
68	    M_BPFJIT, M_NOWAIT);
69	if (filter->mem == NULL) {
70		free(filter, M_BPFJIT);
71		return NULL;
72	}
73
74	/* Create the binary */
75	if ((filter->func = bpf_jit_compile(fp, nins, filter->mem)) == NULL) {
76		free(filter->mem, M_BPFJIT);
77		free(filter, M_BPFJIT);
78		return NULL;
79	}
80
81	return filter;
82}
83
84void
85bpf_destroy_jit_filter(bpf_jit_filter *filter)
86{
87
88	free(filter->mem, M_BPFJIT);
89	free(filter->func, M_BPFJIT);
90	free(filter, M_BPFJIT);
91}
92