bpf.h revision 13937
1/* 2 * Copyright (c) 1990, 1991, 1993 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)bpf.h 8.1 (Berkeley) 6/10/93 39 * 40 * $Id: bpf.h,v 1.8 1996/01/30 22:57:38 mpp Exp $ 41 */ 42 43#ifndef _NET_BPF_H_ 44#define _NET_BPF_H_ 45 46/* 47 * Alignment macros. BPF_WORDALIGN rounds up to the next 48 * even multiple of BPF_ALIGNMENT. 49 */ 50#define BPF_ALIGNMENT sizeof(long) 51#define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1)) 52 53#define BPF_MAXINSNS 512 54#define BPF_MAXBUFSIZE 0x8000 55#define BPF_MINBUFSIZE 32 56 57/* 58 * Structure for BIOCSETF. 59 */ 60struct bpf_program { 61 u_int bf_len; 62 struct bpf_insn *bf_insns; 63}; 64 65/* 66 * Struct returned by BIOCGSTATS. 67 */ 68struct bpf_stat { 69 u_int bs_recv; /* number of packets received */ 70 u_int bs_drop; /* number of packets dropped */ 71}; 72 73/* 74 * Struct return by BIOCVERSION. This represents the version number of 75 * the filter language described by the instruction encodings below. 76 * bpf understands a program iff kernel_major == filter_major && 77 * kernel_minor >= filter_minor, that is, if the value returned by the 78 * running kernel has the same major number and a minor number equal 79 * equal to or less than the filter being downloaded. Otherwise, the 80 * results are undefined, meaning an error may be returned or packets 81 * may be accepted haphazardly. 82 * It has nothing to do with the source code version. 83 */ 84struct bpf_version { 85 u_short bv_major; 86 u_short bv_minor; 87}; 88/* Current version number. */ 89#define BPF_MAJOR_VERSION 1 90#define BPF_MINOR_VERSION 1 91 92#define BIOCGBLEN _IOR('B',102, u_int) 93#define BIOCSBLEN _IOWR('B',102, u_int) 94#define BIOCSETF _IOW('B',103, struct bpf_program) 95#define BIOCFLUSH _IO('B',104) 96#define BIOCPROMISC _IO('B',105) 97#define BIOCGDLT _IOR('B',106, u_int) 98#define BIOCGETIF _IOR('B',107, struct ifreq) 99#define BIOCSETIF _IOW('B',108, struct ifreq) 100#define BIOCSRTIMEOUT _IOW('B',109, struct timeval) 101#define BIOCGRTIMEOUT _IOR('B',110, struct timeval) 102#define BIOCGSTATS _IOR('B',111, struct bpf_stat) 103#define BIOCIMMEDIATE _IOW('B',112, u_int) 104#define BIOCVERSION _IOR('B',113, struct bpf_version) 105#define BIOCGRSIG _IOR('B',114, u_int) 106#define BIOCSRSIG _IOW('B',115, u_int) 107 108/* 109 * Structure prepended to each packet. 110 */ 111struct bpf_hdr { 112 struct timeval bh_tstamp; /* time stamp */ 113 u_long bh_caplen; /* length of captured portion */ 114 u_long bh_datalen; /* original length of packet */ 115 u_short bh_hdrlen; /* length of bpf header (this struct 116 plus alignment padding) */ 117}; 118/* 119 * Because the structure above is not a multiple of 4 bytes, some compilers 120 * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work. 121 * Only the kernel needs to know about it; applications use bh_hdrlen. 122 */ 123#ifdef KERNEL 124#define SIZEOF_BPF_HDR 18 125#endif 126 127/* 128 * Data-link level type codes. 129 * Currently, only DLT_EN10MB and DLT_SLIP are supported. 130 */ 131#define DLT_NULL 0 /* no link-layer encapsulation */ 132#define DLT_EN10MB 1 /* Ethernet (10Mb) */ 133#define DLT_EN3MB 2 /* Experimental Ethernet (3Mb) */ 134#define DLT_AX25 3 /* Amateur Radio AX.25 */ 135#define DLT_PRONET 4 /* Proteon ProNET Token Ring */ 136#define DLT_CHAOS 5 /* Chaos */ 137#define DLT_IEEE802 6 /* IEEE 802 Networks */ 138#define DLT_ARCNET 7 /* ARCNET */ 139#define DLT_SLIP 8 /* Serial Line IP */ 140#define DLT_PPP 9 /* Point-to-point Protocol */ 141#define DLT_FDDI 10 /* FDDI */ 142 143/* 144 * The instruction encodings. 145 */ 146/* instruction classes */ 147#define BPF_CLASS(code) ((code) & 0x07) 148#define BPF_LD 0x00 149#define BPF_LDX 0x01 150#define BPF_ST 0x02 151#define BPF_STX 0x03 152#define BPF_ALU 0x04 153#define BPF_JMP 0x05 154#define BPF_RET 0x06 155#define BPF_MISC 0x07 156 157/* ld/ldx fields */ 158#define BPF_SIZE(code) ((code) & 0x18) 159#define BPF_W 0x00 160#define BPF_H 0x08 161#define BPF_B 0x10 162#define BPF_MODE(code) ((code) & 0xe0) 163#define BPF_IMM 0x00 164#define BPF_ABS 0x20 165#define BPF_IND 0x40 166#define BPF_MEM 0x60 167#define BPF_LEN 0x80 168#define BPF_MSH 0xa0 169 170/* alu/jmp fields */ 171#define BPF_OP(code) ((code) & 0xf0) 172#define BPF_ADD 0x00 173#define BPF_SUB 0x10 174#define BPF_MUL 0x20 175#define BPF_DIV 0x30 176#define BPF_OR 0x40 177#define BPF_AND 0x50 178#define BPF_LSH 0x60 179#define BPF_RSH 0x70 180#define BPF_NEG 0x80 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#define BPF_SRC(code) ((code) & 0x08) 187#define BPF_K 0x00 188#define BPF_X 0x08 189 190/* ret - BPF_K and BPF_X also apply */ 191#define BPF_RVAL(code) ((code) & 0x18) 192#define BPF_A 0x10 193 194/* misc */ 195#define BPF_MISCOP(code) ((code) & 0xf8) 196#define BPF_TAX 0x00 197#define BPF_TXA 0x80 198 199/* 200 * The instruction data structure. 201 */ 202struct bpf_insn { 203 u_short code; 204 u_char jt; 205 u_char jf; 206 long k; 207}; 208 209/* 210 * Macros for insn array initializers. 211 */ 212#define BPF_STMT(code, k) { (u_short)(code), 0, 0, k } 213#define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k } 214 215#ifdef KERNEL 216int bpf_validate __P((struct bpf_insn *, int)); 217void bpf_tap __P((struct ifnet *, u_char *, u_int)); 218void bpf_mtap __P((struct ifnet *, struct mbuf *)); 219void bpfattach __P((struct ifnet *, u_int, u_int)); 220void bpfilterattach __P((int)); 221u_int bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int)); 222#endif 223 224/* 225 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST). 226 */ 227#define BPF_MEMWORDS 16 228 229#endif 230