xref: /freebsd/sys/net/bpf_jitter.c (revision 94942af266ac119ede0ca836f9aa5a5ac0582938)
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("$FreeBSD$");
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 
46 MALLOC_DEFINE(M_BPFJIT, "BPF_JIT", "BPF JIT compiler");
47 
48 bpf_filter_func	bpf_jit_compile(struct bpf_insn *, u_int, int *);
49 
50 SYSCTL_NODE(_net, OID_AUTO, bpf_jitter, CTLFLAG_RW, 0, "BPF JIT compiler");
51 int bpf_jitter_enable = 1;
52 SYSCTL_INT(_net_bpf_jitter, OID_AUTO, enable, CTLFLAG_RW,
53     &bpf_jitter_enable, 0, "enable BPF JIT compiler");
54 
55 bpf_jit_filter *
56 bpf_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 
84 void
85 bpf_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