1 /*- 2 * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from the Stanford/CMU enet packet filter, 6 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 7 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 8 * Berkeley Laboratory. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)bpf.h 7.1 (Berkeley) 5/7/91 35 */ 36 37 /* 38 * This is libpcap's cut-down version of bpf.h; it includes only 39 * the stuff needed for the code generator and the userland BPF 40 * interpreter, and the libpcap APIs for setting filters, etc.. 41 * 42 * "pcap-bpf.c" will include the native OS version, as it deals with 43 * the OS's BPF implementation. 44 * 45 * At least two programs found by Google Code Search explicitly includes 46 * <pcap/bpf.h> (even though <pcap.h>/<pcap/pcap.h> includes it for you), 47 * so moving that stuff to <pcap/pcap.h> would break the build for some 48 * programs. 49 */ 50 51 /* 52 * If we've already included <net/bpf.h>, don't re-define this stuff. 53 * We assume BSD-style multiple-include protection in <net/bpf.h>, 54 * which is true of all but the oldest versions of FreeBSD and NetBSD, 55 * or Tru64 UNIX-style multiple-include protection (or, at least, 56 * Tru64 UNIX 5.x-style; I don't have earlier versions available to check), 57 * or AIX-style multiple-include protection (or, at least, AIX 5.x-style; 58 * I don't have earlier versions available to check), or QNX-style 59 * multiple-include protection (as per GitHub pull request #394). 60 * 61 * We trust that they will define structures and macros and types in 62 * a fashion that's source-compatible and binary-compatible with our 63 * definitions. 64 * 65 * We do not check for BPF_MAJOR_VERSION, as that's defined by 66 * <linux/filter.h>, which is directly or indirectly included in some 67 * programs that also include pcap.h, and <linux/filter.h> doesn't 68 * define stuff we need. We *do* protect against <linux/filter.h> 69 * defining various macros for BPF code itself; <linux/filter.h> says 70 * 71 * Try and keep these values and structures similar to BSD, especially 72 * the BPF code definitions which need to match so you can share filters 73 * 74 * so we trust that it will define them in a fashion that's source-compatible 75 * and binary-compatible with our definitions. 76 * 77 * This also provides our own multiple-include protection. 78 */ 79 #if !defined(_NET_BPF_H_) && !defined(_NET_BPF_H_INCLUDED) && !defined(_BPF_H_) && !defined(_H_BPF) && !defined(lib_pcap_bpf_h) 80 #define lib_pcap_bpf_h 81 82 #include <pcap/funcattrs.h> 83 84 #include <pcap/dlt.h> 85 86 #ifdef __cplusplus 87 extern "C" { 88 #endif 89 90 /* BSD style release date */ 91 #define BPF_RELEASE 199606 92 93 #ifdef MSDOS /* must be 32-bit */ 94 typedef long bpf_int32; 95 typedef unsigned long bpf_u_int32; 96 #else 97 typedef int bpf_int32; 98 typedef u_int bpf_u_int32; 99 #endif 100 101 /* 102 * Alignment macros. BPF_WORDALIGN rounds up to the next 103 * even multiple of BPF_ALIGNMENT. 104 * 105 * Tcpdump's print-pflog.c uses this, so we define it here. 106 */ 107 #ifndef __NetBSD__ 108 #define BPF_ALIGNMENT sizeof(bpf_int32) 109 #else 110 #define BPF_ALIGNMENT sizeof(long) 111 #endif 112 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1)) 113 114 /* 115 * Structure for "pcap_compile()", "pcap_setfilter()", etc.. 116 */ 117 struct bpf_program { 118 u_int bf_len; 119 struct bpf_insn *bf_insns; 120 }; 121 122 /* 123 * The instruction encodings. 124 * 125 * Please inform tcpdump-workers@lists.tcpdump.org if you use any 126 * of the reserved values, so that we can note that they're used 127 * (and perhaps implement it in the reference BPF implementation 128 * and encourage its implementation elsewhere). 129 */ 130 131 /* 132 * The upper 8 bits of the opcode aren't used. BSD/OS used 0x8000. 133 */ 134 135 /* instruction classes */ 136 #define BPF_CLASS(code) ((code) & 0x07) 137 #define BPF_LD 0x00 138 #define BPF_LDX 0x01 139 #define BPF_ST 0x02 140 #define BPF_STX 0x03 141 #define BPF_ALU 0x04 142 #define BPF_JMP 0x05 143 #define BPF_RET 0x06 144 #define BPF_MISC 0x07 145 146 /* ld/ldx fields */ 147 #define BPF_SIZE(code) ((code) & 0x18) 148 #define BPF_W 0x00 149 #define BPF_H 0x08 150 #define BPF_B 0x10 151 /* 0x18 reserved; used by BSD/OS */ 152 #define BPF_MODE(code) ((code) & 0xe0) 153 #define BPF_IMM 0x00 154 #define BPF_ABS 0x20 155 #define BPF_IND 0x40 156 #define BPF_MEM 0x60 157 #define BPF_LEN 0x80 158 #define BPF_MSH 0xa0 159 /* 0xc0 reserved; used by BSD/OS */ 160 /* 0xe0 reserved; used by BSD/OS */ 161 162 /* alu/jmp fields */ 163 #define BPF_OP(code) ((code) & 0xf0) 164 #define BPF_ADD 0x00 165 #define BPF_SUB 0x10 166 #define BPF_MUL 0x20 167 #define BPF_DIV 0x30 168 #define BPF_OR 0x40 169 #define BPF_AND 0x50 170 #define BPF_LSH 0x60 171 #define BPF_RSH 0x70 172 #define BPF_NEG 0x80 173 #define BPF_MOD 0x90 174 #define BPF_XOR 0xa0 175 /* 0xb0 reserved */ 176 /* 0xc0 reserved */ 177 /* 0xd0 reserved */ 178 /* 0xe0 reserved */ 179 /* 0xf0 reserved */ 180 181 #define BPF_JA 0x00 182 #define BPF_JEQ 0x10 183 #define BPF_JGT 0x20 184 #define BPF_JGE 0x30 185 #define BPF_JSET 0x40 186 /* 0x50 reserved; used on BSD/OS */ 187 /* 0x60 reserved */ 188 /* 0x70 reserved */ 189 /* 0x80 reserved */ 190 /* 0x90 reserved */ 191 /* 0xa0 reserved */ 192 /* 0xb0 reserved */ 193 /* 0xc0 reserved */ 194 /* 0xd0 reserved */ 195 /* 0xe0 reserved */ 196 /* 0xf0 reserved */ 197 #define BPF_SRC(code) ((code) & 0x08) 198 #define BPF_K 0x00 199 #define BPF_X 0x08 200 201 /* ret - BPF_K and BPF_X also apply */ 202 #define BPF_RVAL(code) ((code) & 0x18) 203 #define BPF_A 0x10 204 /* 0x18 reserved */ 205 206 /* misc */ 207 #define BPF_MISCOP(code) ((code) & 0xf8) 208 #define BPF_TAX 0x00 209 /* 0x08 reserved */ 210 /* 0x10 reserved */ 211 /* 0x18 reserved */ 212 /* #define BPF_COP 0x20 NetBSD "coprocessor" extensions */ 213 /* 0x28 reserved */ 214 /* 0x30 reserved */ 215 /* 0x38 reserved */ 216 /* #define BPF_COPX 0x40 NetBSD "coprocessor" extensions */ 217 /* also used on BSD/OS */ 218 /* 0x48 reserved */ 219 /* 0x50 reserved */ 220 /* 0x58 reserved */ 221 /* 0x60 reserved */ 222 /* 0x68 reserved */ 223 /* 0x70 reserved */ 224 /* 0x78 reserved */ 225 #define BPF_TXA 0x80 226 /* 0x88 reserved */ 227 /* 0x90 reserved */ 228 /* 0x98 reserved */ 229 /* 0xa0 reserved */ 230 /* 0xa8 reserved */ 231 /* 0xb0 reserved */ 232 /* 0xb8 reserved */ 233 /* 0xc0 reserved; used on BSD/OS */ 234 /* 0xc8 reserved */ 235 /* 0xd0 reserved */ 236 /* 0xd8 reserved */ 237 /* 0xe0 reserved */ 238 /* 0xe8 reserved */ 239 /* 0xf0 reserved */ 240 /* 0xf8 reserved */ 241 242 /* 243 * The instruction data structure. 244 */ 245 struct bpf_insn { 246 u_short code; 247 u_char jt; 248 u_char jf; 249 bpf_u_int32 k; 250 }; 251 252 /* 253 * Macros for insn array initializers. 254 * 255 * In case somebody's included <linux/filter.h>, or something else that 256 * gives the kernel's definitions of BPF statements, get rid of its 257 * definitions, so we can supply ours instead. If some kernel's 258 * definitions aren't *binary-compatible* with what BPF has had 259 * since it first sprung from the brows of Van Jacobson and Steve 260 * McCanne, that kernel should be fixed. 261 */ 262 #ifdef BPF_STMT 263 #undef BPF_STMT 264 #endif 265 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k } 266 #ifdef BPF_JUMP 267 #undef BPF_JUMP 268 #endif 269 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k } 270 271 PCAP_AVAILABLE_0_4 272 PCAP_API u_int bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int); 273 274 PCAP_AVAILABLE_0_6 275 PCAP_API int bpf_validate(const struct bpf_insn *f, int len); 276 277 PCAP_AVAILABLE_0_4 278 PCAP_API char *bpf_image(const struct bpf_insn *, int); 279 280 PCAP_AVAILABLE_0_6 281 PCAP_API void bpf_dump(const struct bpf_program *, int); 282 283 /* 284 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST). 285 */ 286 #define BPF_MEMWORDS 16 287 288 #ifdef __cplusplus 289 } 290 #endif 291 292 #endif /* !defined(_NET_BPF_H_) && !defined(_BPF_H_) && !defined(_H_BPF) && !defined(lib_pcap_bpf_h) */ 293