FreeBSD/Linux Kernel Cross Reference
sys/net/bpf_jitter.c
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
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: src/sys/net/bpf_jitter.c,v 1.8 2008/08/28 16:40:51 jkim Exp $");
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 <string.h>
46 #include <sys/types.h>
47 #endif
48
49 #include <net/bpf.h>
50 #include <net/bpf_jitter.h>
51
52 bpf_filter_func bpf_jit_compile(struct bpf_insn *, u_int, int *);
53
54 static u_int bpf_jit_accept_all(u_char *, u_int, u_int);
55
56 #ifdef _KERNEL
57 MALLOC_DEFINE(M_BPFJIT, "BPF_JIT", "BPF JIT compiler");
58
59 SYSCTL_NODE(_net, OID_AUTO, bpf_jitter, CTLFLAG_RW, 0, "BPF JIT compiler");
60 int bpf_jitter_enable = 1;
61 SYSCTL_INT(_net_bpf_jitter, OID_AUTO, enable, CTLFLAG_RW,
62 &bpf_jitter_enable, 0, "enable BPF JIT compiler");
63
64 bpf_jit_filter *
65 bpf_jitter(struct bpf_insn *fp, int nins)
66 {
67 bpf_jit_filter *filter;
68
69 /* Allocate the filter structure */
70 filter = (struct bpf_jit_filter *)malloc(sizeof(*filter),
71 M_BPFJIT, M_NOWAIT | M_ZERO);
72 if (filter == NULL)
73 return (NULL);
74
75 /* No filter means accept all */
76 if (fp == NULL || nins == 0) {
77 filter->func = bpf_jit_accept_all;
78 return (filter);
79 }
80
81 /* Create the binary */
82 if ((filter->func = bpf_jit_compile(fp, nins, filter->mem)) == NULL) {
83 free(filter, M_BPFJIT);
84 return (NULL);
85 }
86
87 return (filter);
88 }
89
90 void
91 bpf_destroy_jit_filter(bpf_jit_filter *filter)
92 {
93
94 if (filter->func != bpf_jit_accept_all)
95 free(filter->func, M_BPFJIT);
96 free(filter, M_BPFJIT);
97 }
98 #else
99 bpf_jit_filter *
100 bpf_jitter(struct bpf_insn *fp, int nins)
101 {
102 bpf_jit_filter *filter;
103
104 /* Allocate the filter structure */
105 filter = (struct bpf_jit_filter *)malloc(sizeof(*filter));
106 if (filter == NULL)
107 return (NULL);
108 memset(filter, 0, sizeof(*filter));
109
110 /* No filter means accept all */
111 if (fp == NULL || nins == 0) {
112 filter->func = bpf_jit_accept_all;
113 return (filter);
114 }
115
116 /* Create the binary */
117 if ((filter->func = bpf_jit_compile(fp, nins, filter->mem)) == NULL) {
118 free(filter);
119 return (NULL);
120 }
121
122 return (filter);
123 }
124
125 void
126 bpf_destroy_jit_filter(bpf_jit_filter *filter)
127 {
128
129 if (filter->func != bpf_jit_accept_all)
130 free(filter->func);
131 free(filter);
132 }
133 #endif
134
135 static u_int
136 bpf_jit_accept_all(__unused u_char *p, __unused u_int wirelen,
137 __unused u_int buflen)
138 {
139
140 return ((u_int)-1);
141 }
142
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