bpf.h revision 38423
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 * @(#)bpf.h 1.34 (LBL) 6/16/96 40 * 41 * $Id: bpf.h,v 1.13 1998/07/13 10:44:02 bde Exp $ 42 */ 43 44#ifndef _NET_BPF_H_ 45#define _NET_BPF_H_ 46 47/* BSD style release date */ 48#define BPF_RELEASE 199606 49 50typedef int32_t bpf_int32; 51typedef u_int32_t bpf_u_int32; 52 53/* 54 * Alignment macros. BPF_WORDALIGN rounds up to the next 55 * even multiple of BPF_ALIGNMENT. 56 */ 57#define BPF_ALIGNMENT sizeof(bpf_int32) 58#define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1)) 59 60#define BPF_MAXINSNS 512 61#define BPF_MAXBUFSIZE 0x8000 62#define BPF_MINBUFSIZE 32 63 64/* 65 * Structure for BIOCSETF. 66 */ 67struct bpf_program { 68 u_int bf_len; 69 struct bpf_insn *bf_insns; 70}; 71 72/* 73 * Struct returned by BIOCGSTATS. 74 */ 75struct bpf_stat { 76 u_int bs_recv; /* number of packets received */ 77 u_int bs_drop; /* number of packets dropped */ 78}; 79 80/* 81 * Struct return by BIOCVERSION. This represents the version number of 82 * the filter language described by the instruction encodings below. 83 * bpf understands a program iff kernel_major == filter_major && 84 * kernel_minor >= filter_minor, that is, if the value returned by the 85 * running kernel has the same major number and a minor number equal 86 * equal to or less than the filter being downloaded. Otherwise, the 87 * results are undefined, meaning an error may be returned or packets 88 * may be accepted haphazardly. 89 * It has nothing to do with the source code version. 90 */ 91struct bpf_version { 92 u_short bv_major; 93 u_short bv_minor; 94}; 95/* Current version number of filter architecture. */ 96#define BPF_MAJOR_VERSION 1 97#define BPF_MINOR_VERSION 1 98 99#define BIOCGBLEN _IOR('B',102, u_int) 100#define BIOCSBLEN _IOWR('B',102, u_int) 101#define BIOCSETF _IOW('B',103, struct bpf_program) 102#define BIOCFLUSH _IO('B',104) 103#define BIOCPROMISC _IO('B',105) 104#define BIOCGDLT _IOR('B',106, u_int) 105#define BIOCGETIF _IOR('B',107, struct ifreq) 106#define BIOCSETIF _IOW('B',108, struct ifreq) 107#define BIOCSRTIMEOUT _IOW('B',109, struct timeval) 108#define BIOCGRTIMEOUT _IOR('B',110, struct timeval) 109#define BIOCGSTATS _IOR('B',111, struct bpf_stat) 110#define BIOCIMMEDIATE _IOW('B',112, u_int) 111#define BIOCVERSION _IOR('B',113, struct bpf_version) 112#define BIOCGRSIG _IOR('B',114, u_int) 113#define BIOCSRSIG _IOW('B',115, u_int) 114 115/* 116 * Structure prepended to each packet. 117 */ 118struct bpf_hdr { 119 struct timeval bh_tstamp; /* time stamp */ 120 bpf_u_int32 bh_caplen; /* length of captured portion */ 121 bpf_u_int32 bh_datalen; /* original length of packet */ 122 u_short bh_hdrlen; /* length of bpf header (this struct 123 plus alignment padding) */ 124}; 125/* 126 * Because the structure above is not a multiple of 4 bytes, some compilers 127 * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work. 128 * Only the kernel needs to know about it; applications use bh_hdrlen. 129 */ 130#ifdef KERNEL 131#define SIZEOF_BPF_HDR (sizeof(struct bpf_hdr) <= 20 ? 18 : \ 132 sizeof(struct bpf_hdr)) 133#endif 134 135/* 136 * Data-link level type codes. 137 */ 138#define DLT_NULL 0 /* no link-layer encapsulation */ 139#define DLT_EN10MB 1 /* Ethernet (10Mb) */ 140#define DLT_EN3MB 2 /* Experimental Ethernet (3Mb) */ 141#define DLT_AX25 3 /* Amateur Radio AX.25 */ 142#define DLT_PRONET 4 /* Proteon ProNET Token Ring */ 143#define DLT_CHAOS 5 /* Chaos */ 144#define DLT_IEEE802 6 /* IEEE 802 Networks */ 145#define DLT_ARCNET 7 /* ARCNET */ 146#define DLT_SLIP 8 /* Serial Line IP */ 147#define DLT_PPP 9 /* Point-to-point Protocol */ 148#define DLT_FDDI 10 /* FDDI */ 149#define DLT_ATM_RFC1483 11 /* LLC/SNAP encapsulated atm */ 150#define DLT_RAW 12 /* raw IP */ 151 152/* 153 * The instruction encodings. 154 */ 155/* instruction classes */ 156#define BPF_CLASS(code) ((code) & 0x07) 157#define BPF_LD 0x00 158#define BPF_LDX 0x01 159#define BPF_ST 0x02 160#define BPF_STX 0x03 161#define BPF_ALU 0x04 162#define BPF_JMP 0x05 163#define BPF_RET 0x06 164#define BPF_MISC 0x07 165 166/* ld/ldx fields */ 167#define BPF_SIZE(code) ((code) & 0x18) 168#define BPF_W 0x00 169#define BPF_H 0x08 170#define BPF_B 0x10 171#define BPF_MODE(code) ((code) & 0xe0) 172#define BPF_IMM 0x00 173#define BPF_ABS 0x20 174#define BPF_IND 0x40 175#define BPF_MEM 0x60 176#define BPF_LEN 0x80 177#define BPF_MSH 0xa0 178 179/* alu/jmp fields */ 180#define BPF_OP(code) ((code) & 0xf0) 181#define BPF_ADD 0x00 182#define BPF_SUB 0x10 183#define BPF_MUL 0x20 184#define BPF_DIV 0x30 185#define BPF_OR 0x40 186#define BPF_AND 0x50 187#define BPF_LSH 0x60 188#define BPF_RSH 0x70 189#define BPF_NEG 0x80 190#define BPF_JA 0x00 191#define BPF_JEQ 0x10 192#define BPF_JGT 0x20 193#define BPF_JGE 0x30 194#define BPF_JSET 0x40 195#define BPF_SRC(code) ((code) & 0x08) 196#define BPF_K 0x00 197#define BPF_X 0x08 198 199/* ret - BPF_K and BPF_X also apply */ 200#define BPF_RVAL(code) ((code) & 0x18) 201#define BPF_A 0x10 202 203/* misc */ 204#define BPF_MISCOP(code) ((code) & 0xf8) 205#define BPF_TAX 0x00 206#define BPF_TXA 0x80 207 208/* 209 * The instruction data structure. 210 */ 211struct bpf_insn { 212 u_short code; 213 u_char jt; 214 u_char jf; 215 bpf_u_int32 k; 216}; 217 218/* 219 * Macros for insn array initializers. 220 */ 221#define BPF_STMT(code, k) { (u_short)(code), 0, 0, k } 222#define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k } 223 224#ifdef KERNEL 225int bpf_validate __P((struct bpf_insn *, int)); 226void bpf_tap __P((struct ifnet *, u_char *, u_int)); 227void bpf_mtap __P((struct ifnet *, struct mbuf *)); 228void bpfattach __P((struct ifnet *, u_int, u_int)); 229void bpfilterattach __P((int)); 230u_int bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int)); 231#endif 232 233/* 234 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST). 235 */ 236#define BPF_MEMWORDS 16 237 238#endif 239