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 __FBSDID("$FreeBSD$"); 36 37 #ifdef _KERNEL 38 #include "opt_bpf.h" 39 40 #include <sys/param.h> 41 #include <sys/kernel.h> 42 #include <sys/malloc.h> 43 #include <sys/mbuf.h> 44 #include <sys/sysctl.h> 45 #else 46 #include <stdlib.h> 47 #include <sys/mman.h> 48 #include <sys/param.h> 49 #include <sys/types.h> 50 #endif 51 52 #include <net/bpf.h> 53 #include <net/bpf_jitter.h> 54 55 static u_int bpf_jit_accept_all(u_char *, u_int, u_int); 56 57 #ifdef _KERNEL 58 MALLOC_DEFINE(M_BPFJIT, "BPF_JIT", "BPF JIT compiler"); 59 60 SYSCTL_NODE(_net, OID_AUTO, bpf_jitter, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 61 "BPF JIT compiler"); 62 int bpf_jitter_enable = 1; 63 SYSCTL_INT(_net_bpf_jitter, OID_AUTO, enable, CTLFLAG_RW, 64 &bpf_jitter_enable, 0, "enable BPF JIT compiler"); 65 #endif 66 67 bpf_jit_filter * 68 bpf_jitter(struct bpf_insn *fp, int nins) 69 { 70 bpf_jit_filter *filter; 71 72 /* Allocate the filter structure. */ 73 #ifdef _KERNEL 74 filter = (struct bpf_jit_filter *)malloc(sizeof(*filter), 75 M_BPFJIT, M_NOWAIT); 76 #else 77 filter = (struct bpf_jit_filter *)malloc(sizeof(*filter)); 78 #endif 79 if (filter == NULL) 80 return (NULL); 81 82 /* No filter means accept all. */ 83 if (fp == NULL || nins == 0) { 84 filter->func = bpf_jit_accept_all; 85 return (filter); 86 } 87 88 /* Create the binary. */ 89 if ((filter->func = bpf_jit_compile(fp, nins, &filter->size)) == NULL) { 90 #ifdef _KERNEL 91 free(filter, M_BPFJIT); 92 #else 93 free(filter); 94 #endif 95 return (NULL); 96 } 97 98 return (filter); 99 } 100 101 void 102 bpf_destroy_jit_filter(bpf_jit_filter *filter) 103 { 104 105 #ifdef _KERNEL 106 if (filter->func != bpf_jit_accept_all) 107 free(filter->func, M_BPFJIT); 108 free(filter, M_BPFJIT); 109 #else 110 if (filter->func != bpf_jit_accept_all) 111 munmap(filter->func, filter->size); 112 free(filter); 113 #endif 114 } 115 116 static u_int 117 bpf_jit_accept_all(__unused u_char *p, __unused u_int wirelen, 118 __unused u_int buflen) 119 { 120 121 return ((u_int)-1); 122 } 123