1/*-
2 * Copyright (C) 2002-2003 NetGroup, Politecnico di Torino (Italy)
3 * Copyright (C) 2005-2009 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("$FreeBSD$");
34
35#ifdef _KERNEL
36#include "opt_bpf.h"
37
38#include <sys/param.h>
39#include <sys/kernel.h>
40#include <sys/malloc.h>
41#include <sys/mbuf.h>
42#include <sys/sysctl.h>
43#else
44#include <stdlib.h>
45#include <sys/mman.h>
46#include <sys/param.h>
47#include <sys/types.h>
48#endif
49
50#include <net/bpf.h>
51#include <net/bpf_jitter.h>
52
53bpf_filter_func	bpf_jit_compile(struct bpf_insn *, u_int, size_t *);
54
55static u_int	bpf_jit_accept_all(u_char *, u_int, u_int);
56
57#ifdef _KERNEL
58MALLOC_DEFINE(M_BPFJIT, "BPF_JIT", "BPF JIT compiler");
59
60SYSCTL_NODE(_net, OID_AUTO, bpf_jitter, CTLFLAG_RW, 0, "BPF JIT compiler");
61int bpf_jitter_enable = 1;
62SYSCTL_INT(_net_bpf_jitter, OID_AUTO, enable, CTLFLAG_RW,
63    &bpf_jitter_enable, 0, "enable BPF JIT compiler");
64#endif
65
66bpf_jit_filter *
67bpf_jitter(struct bpf_insn *fp, int nins)
68{
69	bpf_jit_filter *filter;
70
71	/* Allocate the filter structure. */
72#ifdef _KERNEL
73	filter = (struct bpf_jit_filter *)malloc(sizeof(*filter),
74	    M_BPFJIT, M_NOWAIT);
75#else
76	filter = (struct bpf_jit_filter *)malloc(sizeof(*filter));
77#endif
78	if (filter == NULL)
79		return (NULL);
80
81	/* No filter means accept all. */
82	if (fp == NULL || nins == 0) {
83		filter->func = bpf_jit_accept_all;
84		return (filter);
85	}
86
87	/* Create the binary. */
88	if ((filter->func = bpf_jit_compile(fp, nins, &filter->size)) == NULL) {
89#ifdef _KERNEL
90		free(filter, M_BPFJIT);
91#else
92		free(filter);
93#endif
94		return (NULL);
95	}
96
97	return (filter);
98}
99
100void
101bpf_destroy_jit_filter(bpf_jit_filter *filter)
102{
103
104#ifdef _KERNEL
105	if (filter->func != bpf_jit_accept_all)
106		free(filter->func, M_BPFJIT);
107	free(filter, M_BPFJIT);
108#else
109	if (filter->func != bpf_jit_accept_all)
110		munmap(filter->func, filter->size);
111	free(filter);
112#endif
113}
114
115static u_int
116bpf_jit_accept_all(__unused u_char *p, __unused u_int wirelen,
117    __unused u_int buflen)
118{
119
120	return ((u_int)-1);
121}
122