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 do not check for BPF_MAJOR_VERSION, as that's defined by 62 * <linux/filter.h>, which is directly or indirectly included in some 63 * programs that also include pcap.h, and <linux/filter.h> doesn't 64 * define stuff we need. 65 * 66 * This also provides our own multiple-include protection. 67 */ 68 #if !defined(_NET_BPF_H_) && !defined(_NET_BPF_H_INCLUDED) && !defined(_BPF_H_) && !defined(_H_BPF) && !defined(lib_pcap_bpf_h) 69 #define lib_pcap_bpf_h 70 71 #include <pcap/funcattrs.h> 72 73 #ifdef __cplusplus 74 extern "C" { 75 #endif 76 77 /* 78 * In the past, we modified pcap/pcap.h to include the system net/bpf.h, 79 * rather than this file. However, starting around 1.10.2, libpcap requires 80 * the extern functions defined here to build. Simply reverting that local 81 * change is not a solution, because some ports with '#include <pcap.h>' 82 * such as mail/spamd and net/xprobe require the system net/bpf.h to be 83 * pulled in. To accommodate both requirements, make this header a wrapper 84 * around the system net/bpf.h, but keep the extern function definitions. 85 */ 86 #if defined(__FreeBSD__) 87 #include <net/bpf.h> 88 #else 89 /* BSD style release date */ 90 #define BPF_RELEASE 199606 91 92 #ifdef MSDOS /* must be 32-bit */ 93 typedef long bpf_int32; 94 typedef unsigned long bpf_u_int32; 95 #else 96 typedef int bpf_int32; 97 typedef u_int bpf_u_int32; 98 #endif 99 100 /* 101 * Alignment macros. BPF_WORDALIGN rounds up to the next 102 * even multiple of BPF_ALIGNMENT. 103 * 104 * Tcpdump's print-pflog.c uses this, so we define it here. 105 */ 106 #ifndef __NetBSD__ 107 #define BPF_ALIGNMENT sizeof(bpf_int32) 108 #else 109 #define BPF_ALIGNMENT sizeof(long) 110 #endif 111 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1)) 112 113 /* 114 * Structure for "pcap_compile()", "pcap_setfilter()", etc.. 115 */ 116 struct bpf_program { 117 u_int bf_len; 118 struct bpf_insn *bf_insns; 119 }; 120 121 #include <pcap/dlt.h> 122 123 /* 124 * The instruction encodings. 125 * 126 * Please inform tcpdump-workers@lists.tcpdump.org if you use any 127 * of the reserved values, so that we can note that they're used 128 * (and perhaps implement it in the reference BPF implementation 129 * and encourage its implementation elsewhere). 130 */ 131 132 /* 133 * The upper 8 bits of the opcode aren't used. BSD/OS used 0x8000. 134 */ 135 136 /* instruction classes */ 137 #define BPF_CLASS(code) ((code) & 0x07) 138 #define BPF_LD 0x00 139 #define BPF_LDX 0x01 140 #define BPF_ST 0x02 141 #define BPF_STX 0x03 142 #define BPF_ALU 0x04 143 #define BPF_JMP 0x05 144 #define BPF_RET 0x06 145 #define BPF_MISC 0x07 146 147 /* ld/ldx fields */ 148 #define BPF_SIZE(code) ((code) & 0x18) 149 #define BPF_W 0x00 150 #define BPF_H 0x08 151 #define BPF_B 0x10 152 /* 0x18 reserved; used by BSD/OS */ 153 #define BPF_MODE(code) ((code) & 0xe0) 154 #define BPF_IMM 0x00 155 #define BPF_ABS 0x20 156 #define BPF_IND 0x40 157 #define BPF_MEM 0x60 158 #define BPF_LEN 0x80 159 #define BPF_MSH 0xa0 160 /* 0xc0 reserved; used by BSD/OS */ 161 /* 0xe0 reserved; used by BSD/OS */ 162 163 /* alu/jmp fields */ 164 #define BPF_OP(code) ((code) & 0xf0) 165 #define BPF_ADD 0x00 166 #define BPF_SUB 0x10 167 #define BPF_MUL 0x20 168 #define BPF_DIV 0x30 169 #define BPF_OR 0x40 170 #define BPF_AND 0x50 171 #define BPF_LSH 0x60 172 #define BPF_RSH 0x70 173 #define BPF_NEG 0x80 174 #define BPF_MOD 0x90 175 #define BPF_XOR 0xa0 176 /* 0xb0 reserved */ 177 /* 0xc0 reserved */ 178 /* 0xd0 reserved */ 179 /* 0xe0 reserved */ 180 /* 0xf0 reserved */ 181 182 #define BPF_JA 0x00 183 #define BPF_JEQ 0x10 184 #define BPF_JGT 0x20 185 #define BPF_JGE 0x30 186 #define BPF_JSET 0x40 187 /* 0x50 reserved; used on BSD/OS */ 188 /* 0x60 reserved */ 189 /* 0x70 reserved */ 190 /* 0x80 reserved */ 191 /* 0x90 reserved */ 192 /* 0xa0 reserved */ 193 /* 0xb0 reserved */ 194 /* 0xc0 reserved */ 195 /* 0xd0 reserved */ 196 /* 0xe0 reserved */ 197 /* 0xf0 reserved */ 198 #define BPF_SRC(code) ((code) & 0x08) 199 #define BPF_K 0x00 200 #define BPF_X 0x08 201 202 /* ret - BPF_K and BPF_X also apply */ 203 #define BPF_RVAL(code) ((code) & 0x18) 204 #define BPF_A 0x10 205 /* 0x18 reserved */ 206 207 /* misc */ 208 #define BPF_MISCOP(code) ((code) & 0xf8) 209 #define BPF_TAX 0x00 210 /* 0x08 reserved */ 211 /* 0x10 reserved */ 212 /* 0x18 reserved */ 213 /* #define BPF_COP 0x20 NetBSD "coprocessor" extensions */ 214 /* 0x28 reserved */ 215 /* 0x30 reserved */ 216 /* 0x38 reserved */ 217 /* #define BPF_COPX 0x40 NetBSD "coprocessor" extensions */ 218 /* also used on BSD/OS */ 219 /* 0x48 reserved */ 220 /* 0x50 reserved */ 221 /* 0x58 reserved */ 222 /* 0x60 reserved */ 223 /* 0x68 reserved */ 224 /* 0x70 reserved */ 225 /* 0x78 reserved */ 226 #define BPF_TXA 0x80 227 /* 0x88 reserved */ 228 /* 0x90 reserved */ 229 /* 0x98 reserved */ 230 /* 0xa0 reserved */ 231 /* 0xa8 reserved */ 232 /* 0xb0 reserved */ 233 /* 0xb8 reserved */ 234 /* 0xc0 reserved; used on BSD/OS */ 235 /* 0xc8 reserved */ 236 /* 0xd0 reserved */ 237 /* 0xd8 reserved */ 238 /* 0xe0 reserved */ 239 /* 0xe8 reserved */ 240 /* 0xf0 reserved */ 241 /* 0xf8 reserved */ 242 243 /* 244 * The instruction data structure. 245 */ 246 struct bpf_insn { 247 u_short code; 248 u_char jt; 249 u_char jf; 250 bpf_u_int32 k; 251 }; 252 253 /* 254 * Macros for insn array initializers. 255 */ 256 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k } 257 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k } 258 259 #endif /* defined(__FreeBSD__) */ 260 261 PCAP_API int bpf_validate(const struct bpf_insn *, int); 262 PCAP_API u_int bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int); 263 264 #if !defined(__FreeBSD__) 265 /* 266 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST). 267 */ 268 #define BPF_MEMWORDS 16 269 #endif 270 271 #ifdef __cplusplus 272 } 273 #endif 274 275 #endif /* !defined(_NET_BPF_H_) && !defined(_BPF_H_) && !defined(_H_BPF) && !defined(lib_pcap_bpf_h) */ 276