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 #if defined(__FreeBSD__) 84 #include <pcap/dlt.h> 85 #endif 86 87 #ifdef __cplusplus 88 extern "C" { 89 #endif 90 91 /* 92 * In the past, we modified pcap/pcap.h to include the system net/bpf.h, 93 * rather than this file. However, starting around 1.10.2, libpcap requires 94 * the extern functions defined here to build. Simply reverting that local 95 * change is not a solution, because some ports with '#include <pcap.h>' 96 * such as mail/spamd and net/xprobe require the system net/bpf.h to be 97 * pulled in. To accommodate both requirements, make this header a wrapper 98 * around the system net/bpf.h, but keep the extern function definitions. 99 */ 100 #if defined(__FreeBSD__) 101 #include <net/bpf.h> 102 #else 103 /* BSD style release date */ 104 #define BPF_RELEASE 199606 105 106 #ifdef MSDOS /* must be 32-bit */ 107 typedef long bpf_int32; 108 typedef unsigned long bpf_u_int32; 109 #else 110 typedef int bpf_int32; 111 typedef u_int bpf_u_int32; 112 #endif 113 114 /* 115 * Alignment macros. BPF_WORDALIGN rounds up to the next 116 * even multiple of BPF_ALIGNMENT. 117 * 118 * Tcpdump's print-pflog.c uses this, so we define it here. 119 */ 120 #ifndef __NetBSD__ 121 #define BPF_ALIGNMENT sizeof(bpf_int32) 122 #else 123 #define BPF_ALIGNMENT sizeof(long) 124 #endif 125 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1)) 126 127 /* 128 * Structure for "pcap_compile()", "pcap_setfilter()", etc.. 129 */ 130 struct bpf_program { 131 u_int bf_len; 132 struct bpf_insn *bf_insns; 133 }; 134 135 /* 136 * The instruction encodings. 137 * 138 * Please inform tcpdump-workers@lists.tcpdump.org if you use any 139 * of the reserved values, so that we can note that they're used 140 * (and perhaps implement it in the reference BPF implementation 141 * and encourage its implementation elsewhere). 142 */ 143 144 /* 145 * The upper 8 bits of the opcode aren't used. BSD/OS used 0x8000. 146 */ 147 148 /* instruction classes */ 149 #define BPF_CLASS(code) ((code) & 0x07) 150 #define BPF_LD 0x00 151 #define BPF_LDX 0x01 152 #define BPF_ST 0x02 153 #define BPF_STX 0x03 154 #define BPF_ALU 0x04 155 #define BPF_JMP 0x05 156 #define BPF_RET 0x06 157 #define BPF_MISC 0x07 158 159 /* ld/ldx fields */ 160 #define BPF_SIZE(code) ((code) & 0x18) 161 #define BPF_W 0x00 162 #define BPF_H 0x08 163 #define BPF_B 0x10 164 /* 0x18 reserved; used by BSD/OS */ 165 #define BPF_MODE(code) ((code) & 0xe0) 166 #define BPF_IMM 0x00 167 #define BPF_ABS 0x20 168 #define BPF_IND 0x40 169 #define BPF_MEM 0x60 170 #define BPF_LEN 0x80 171 #define BPF_MSH 0xa0 172 /* 0xc0 reserved; used by BSD/OS */ 173 /* 0xe0 reserved; used by BSD/OS */ 174 175 /* alu/jmp fields */ 176 #define BPF_OP(code) ((code) & 0xf0) 177 #define BPF_ADD 0x00 178 #define BPF_SUB 0x10 179 #define BPF_MUL 0x20 180 #define BPF_DIV 0x30 181 #define BPF_OR 0x40 182 #define BPF_AND 0x50 183 #define BPF_LSH 0x60 184 #define BPF_RSH 0x70 185 #define BPF_NEG 0x80 186 #define BPF_MOD 0x90 187 #define BPF_XOR 0xa0 188 /* 0xb0 reserved */ 189 /* 0xc0 reserved */ 190 /* 0xd0 reserved */ 191 /* 0xe0 reserved */ 192 /* 0xf0 reserved */ 193 194 #define BPF_JA 0x00 195 #define BPF_JEQ 0x10 196 #define BPF_JGT 0x20 197 #define BPF_JGE 0x30 198 #define BPF_JSET 0x40 199 /* 0x50 reserved; used on BSD/OS */ 200 /* 0x60 reserved */ 201 /* 0x70 reserved */ 202 /* 0x80 reserved */ 203 /* 0x90 reserved */ 204 /* 0xa0 reserved */ 205 /* 0xb0 reserved */ 206 /* 0xc0 reserved */ 207 /* 0xd0 reserved */ 208 /* 0xe0 reserved */ 209 /* 0xf0 reserved */ 210 #define BPF_SRC(code) ((code) & 0x08) 211 #define BPF_K 0x00 212 #define BPF_X 0x08 213 214 /* ret - BPF_K and BPF_X also apply */ 215 #define BPF_RVAL(code) ((code) & 0x18) 216 #define BPF_A 0x10 217 /* 0x18 reserved */ 218 219 /* misc */ 220 #define BPF_MISCOP(code) ((code) & 0xf8) 221 #define BPF_TAX 0x00 222 /* 0x08 reserved */ 223 /* 0x10 reserved */ 224 /* 0x18 reserved */ 225 /* #define BPF_COP 0x20 NetBSD "coprocessor" extensions */ 226 /* 0x28 reserved */ 227 /* 0x30 reserved */ 228 /* 0x38 reserved */ 229 /* #define BPF_COPX 0x40 NetBSD "coprocessor" extensions */ 230 /* also used on BSD/OS */ 231 /* 0x48 reserved */ 232 /* 0x50 reserved */ 233 /* 0x58 reserved */ 234 /* 0x60 reserved */ 235 /* 0x68 reserved */ 236 /* 0x70 reserved */ 237 /* 0x78 reserved */ 238 #define BPF_TXA 0x80 239 /* 0x88 reserved */ 240 /* 0x90 reserved */ 241 /* 0x98 reserved */ 242 /* 0xa0 reserved */ 243 /* 0xa8 reserved */ 244 /* 0xb0 reserved */ 245 /* 0xb8 reserved */ 246 /* 0xc0 reserved; used on BSD/OS */ 247 /* 0xc8 reserved */ 248 /* 0xd0 reserved */ 249 /* 0xd8 reserved */ 250 /* 0xe0 reserved */ 251 /* 0xe8 reserved */ 252 /* 0xf0 reserved */ 253 /* 0xf8 reserved */ 254 255 /* 256 * The instruction data structure. 257 */ 258 struct bpf_insn { 259 u_short code; 260 u_char jt; 261 u_char jf; 262 bpf_u_int32 k; 263 }; 264 265 /* 266 * Macros for insn array initializers. 267 * 268 * In case somebody's included <linux/filter.h>, or something else that 269 * gives the kernel's definitions of BPF statements, get rid of its 270 * definitions, so we can supply ours instead. If some kernel's 271 * definitions aren't *binary-compatible* with what BPF has had 272 * since it first sprung from the brows of Van Jacobson and Steve 273 * McCanne, that kernel should be fixed. 274 */ 275 #ifdef BPF_STMT 276 #undef BPF_STMT 277 #endif 278 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k } 279 #ifdef BPF_JUMP 280 #undef BPF_JUMP 281 #endif 282 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k } 283 284 #endif /* defined(__FreeBSD__) */ 285 286 PCAP_AVAILABLE_0_4 287 PCAP_API u_int bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int); 288 289 PCAP_AVAILABLE_0_6 290 PCAP_API int bpf_validate(const struct bpf_insn *f, int len); 291 292 PCAP_AVAILABLE_0_4 293 PCAP_API char *bpf_image(const struct bpf_insn *, int); 294 295 PCAP_AVAILABLE_0_6 296 PCAP_API void bpf_dump(const struct bpf_program *, int); 297 298 #if !defined(__FreeBSD__) 299 /* 300 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST). 301 */ 302 #define BPF_MEMWORDS 16 303 #endif 304 305 #ifdef __cplusplus 306 } 307 #endif 308 309 #endif /* !defined(_NET_BPF_H_) && !defined(_BPF_H_) && !defined(_H_BPF) && !defined(lib_pcap_bpf_h) */ 310