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: releng/10.2/sys/net/bpf_jitter.c 199615 2009-11-20 21:12:40Z 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 <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