bpf_jitter.c revision 199498
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: head/sys/net/bpf_jitter.c 199498 2009-11-18 23:40:19Z jkim $"); 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/mman.h> 47#include <sys/param.h> 48#include <sys/types.h> 49#endif 50 51#include <net/bpf.h> 52#include <net/bpf_jitter.h> 53 54bpf_filter_func bpf_jit_compile(struct bpf_insn *, u_int, size_t *, int *); 55 56static u_int bpf_jit_accept_all(u_char *, u_int, u_int); 57 58#ifdef _KERNEL 59MALLOC_DEFINE(M_BPFJIT, "BPF_JIT", "BPF JIT compiler"); 60 61SYSCTL_NODE(_net, OID_AUTO, bpf_jitter, CTLFLAG_RW, 0, "BPF JIT compiler"); 62int bpf_jitter_enable = 1; 63SYSCTL_INT(_net_bpf_jitter, OID_AUTO, enable, CTLFLAG_RW, 64 &bpf_jitter_enable, 0, "enable BPF JIT compiler"); 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 filter = (struct bpf_jit_filter *)malloc(sizeof(*filter), 73 M_BPFJIT, M_NOWAIT | M_ZERO); 74 if (filter == NULL) 75 return (NULL); 76 77 /* No filter means accept all */ 78 if (fp == NULL || nins == 0) { 79 filter->func = bpf_jit_accept_all; 80 return (filter); 81 } 82 83 /* Create the binary */ 84 if ((filter->func = bpf_jit_compile(fp, nins, &filter->size, 85 filter->mem)) == NULL) { 86 free(filter, M_BPFJIT); 87 return (NULL); 88 } 89 90 return (filter); 91} 92 93void 94bpf_destroy_jit_filter(bpf_jit_filter *filter) 95{ 96 97 if (filter->func != bpf_jit_accept_all) 98 contigfree(filter->func, filter->size, M_BPFJIT); 99 free(filter, M_BPFJIT); 100} 101#else 102bpf_jit_filter * 103bpf_jitter(struct bpf_insn *fp, int nins) 104{ 105 bpf_jit_filter *filter; 106 107 /* Allocate the filter structure */ 108 filter = (struct bpf_jit_filter *)malloc(sizeof(*filter)); 109 if (filter == NULL) 110 return (NULL); 111 memset(filter, 0, sizeof(*filter)); 112 113 /* No filter means accept all */ 114 if (fp == NULL || nins == 0) { 115 filter->func = bpf_jit_accept_all; 116 return (filter); 117 } 118 119 /* Create the binary */ 120 if ((filter->func = bpf_jit_compile(fp, nins, &filter->size, 121 filter->mem)) == NULL) { 122 free(filter); 123 return (NULL); 124 } 125 126 return (filter); 127} 128 129void 130bpf_destroy_jit_filter(bpf_jit_filter *filter) 131{ 132 133 if (filter->func != bpf_jit_accept_all) 134 munmap(filter->func, filter->size); 135 free(filter); 136} 137#endif 138 139static u_int 140bpf_jit_accept_all(__unused u_char *p, __unused u_int wirelen, 141 __unused u_int buflen) 142{ 143 144 return ((u_int)-1); 145} 146