1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (C) 2002-2003 NetGroup, Politecnico di Torino (Italy) 5 * Copyright (C) 2005-2017 Jung-uk Kim <jkim@FreeBSD.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the Politecnico di Torino nor the names of its 18 * contributors may be used to endorse or promote products derived from 19 * this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 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 53 static u_int bpf_jit_accept_all(u_char *, u_int, u_int); 54 55 #ifdef _KERNEL 56 MALLOC_DEFINE(M_BPFJIT, "BPF_JIT", "BPF JIT compiler"); 57 58 SYSCTL_NODE(_net, OID_AUTO, bpf_jitter, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 59 "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 #endif 64 65 bpf_jit_filter * 66 bpf_jitter(struct bpf_insn *fp, int nins) 67 { 68 bpf_jit_filter *filter; 69 70 /* Allocate the filter structure. */ 71 #ifdef _KERNEL 72 filter = (struct bpf_jit_filter *)malloc(sizeof(*filter), 73 M_BPFJIT, M_NOWAIT); 74 #else 75 filter = (struct bpf_jit_filter *)malloc(sizeof(*filter)); 76 #endif 77 if (filter == NULL) 78 return (NULL); 79 80 /* No filter means accept all. */ 81 if (fp == NULL || nins == 0) { 82 filter->func = bpf_jit_accept_all; 83 return (filter); 84 } 85 86 /* Create the binary. */ 87 if ((filter->func = bpf_jit_compile(fp, nins, &filter->size)) == NULL) { 88 #ifdef _KERNEL 89 free(filter, M_BPFJIT); 90 #else 91 free(filter); 92 #endif 93 return (NULL); 94 } 95 96 return (filter); 97 } 98 99 void 100 bpf_destroy_jit_filter(bpf_jit_filter *filter) 101 { 102 103 #ifdef _KERNEL 104 if (filter->func != bpf_jit_accept_all) 105 free(filter->func, M_BPFJIT); 106 free(filter, M_BPFJIT); 107 #else 108 if (filter->func != bpf_jit_accept_all) 109 munmap(filter->func, filter->size); 110 free(filter); 111 #endif 112 } 113 114 static u_int 115 bpf_jit_accept_all(__unused u_char *p, __unused u_int wirelen, 116 __unused u_int buflen) 117 { 118 119 return ((u_int)-1); 120 } 121