xref: /netbsd-src/sys/net/bpf.h (revision cda4f8f6ee55684e8d311b86c99ea59191e6b74f)
1 /*-
2  * Copyright (c) 1990-1991 The Regents of the University of California.
3  * 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  *      from: @(#)bpf.h	7.1 (Berkeley) 5/7/91
39  *	$Id: bpf.h,v 1.4 1993/05/20 03:05:50 cgd Exp $
40  */
41 
42 #ifndef _NET_BPF_H_
43 #define _NET_BPF_H_
44 
45 /*
46  * Alignment macros.  BPF_WORDALIGN rounds up to the next
47  * even multiple of BPF_ALIGNMENT.
48  */
49 #define BPF_ALIGNMENT sizeof(long)
50 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
51 
52 #define BPF_MAXINSNS 512
53 #define BPF_MAXBUFSIZE 0x8000
54 #define BPF_MINBUFSIZE 32
55 
56 /*
57  *  Structure for BIOCSETF.
58  */
59 struct bpf_program {
60 	u_int bf_len;
61 	struct bpf_insn *bf_insns;
62 };
63 
64 /*
65  * Struct returned by BIOCGSTATS.
66  */
67 struct bpf_stat {
68 	u_int bs_recv;		/* number of packets received */
69 	u_int bs_drop;		/* number of packets dropped */
70 };
71 
72 /*
73  * Struct return by BIOCVERSION.  This represents the version number of
74  * the filter language described by the instruction encodings below.
75  * bpf understands a program iff kernel_major == filter_major &&
76  * kernel_minor >= filter_minor, that is, if the value returned by the
77  * running kernel has the same major number and a minor number equal
78  * equal to or less than the filter being downloaded.  Otherwise, the
79  * results are undefined, meaning an error may be returned or packets
80  * may be accepted haphazardly.
81  * It has nothing to do with the source code version.
82  */
83 struct bpf_version {
84 	u_short bv_major;
85 	u_short bv_minor;
86 };
87 /* Current version number. */
88 #define BPF_MAJOR_VERSION 1
89 #define BPF_MINOR_VERSION 1
90 
91 /*
92  * BPF ioctls
93  *
94  * The first set is for compatibility with Sun's pcc style
95  * header files.  If your using gcc, we assume that you
96  * have run fixincludes so the latter set should work.
97  */
98 #if (defined(sun) || defined(ibm032)) && !defined(__GNUC__)
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 #else
113 #define	BIOCGBLEN	_IOR('B',102, u_int)
114 #define	BIOCSBLEN	_IOWR('B',102, u_int)
115 #define	BIOCSETF	_IOW('B',103, struct bpf_program)
116 #define	BIOCFLUSH	_IO('B',104)
117 #define BIOCPROMISC	_IO('B',105)
118 #define	BIOCGDLT	_IOR('B',106, u_int)
119 #define BIOCGETIF	_IOR('B',107, struct ifreq)
120 #define BIOCSETIF	_IOW('B',108, struct ifreq)
121 #define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
122 #define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
123 #define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
124 #define BIOCIMMEDIATE	_IOW('B',112, u_int)
125 #define BIOCVERSION	_IOR('B',113, struct bpf_version)
126 #endif
127 
128 /*
129  * Structure prepended to each packet.
130  */
131 struct bpf_hdr {
132 	struct timeval	bh_tstamp;	/* time stamp */
133 	u_long		bh_caplen;	/* length of captured portion */
134 	u_long		bh_datalen;	/* original length of packet */
135 	u_short		bh_hdrlen;	/* length of bpf header (this struct
136 					   plus alignment padding) */
137 };
138 /*
139  * Because the structure above is not a multiple of 4 bytes, some compilers
140  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
141  * Only the kernel needs to know about it; applications use bh_hdrlen.
142  */
143 #ifdef KERNEL
144 #define SIZEOF_BPF_HDR 18
145 #endif
146 
147 /*
148  * Data-link level type codes.
149  * Currently, only DLT_EN10MB and DLT_SLIP are supported.
150  */
151 #define DLT_NULL	0	/* no link-layer encapsulation */
152 #define DLT_EN10MB	1	/* Ethernet (10Mb) */
153 #define DLT_EN3MB	2	/* Experimental Ethernet (3Mb) */
154 #define DLT_AX25	3	/* Amateur Radio AX.25 */
155 #define DLT_PRONET	4	/* Proteon ProNET Token Ring */
156 #define DLT_CHAOS	5	/* Chaos */
157 #define DLT_IEEE802	6	/* IEEE 802 Networks */
158 #define DLT_ARCNET	7	/* ARCNET */
159 #define DLT_SLIP	8	/* Serial Line IP */
160 #define DLT_PPP		9	/* Point-to-point Protocol */
161 #define DLT_FDDI	10	/* FDDI */
162 
163 /*
164  * The instruction encondings.
165  */
166 /* instruction classes */
167 #define BPF_CLASS(code) ((code) & 0x07)
168 #define		BPF_LD		0x00
169 #define		BPF_LDX		0x01
170 #define		BPF_ST		0x02
171 #define		BPF_STX		0x03
172 #define		BPF_ALU		0x04
173 #define		BPF_JMP		0x05
174 #define		BPF_RET		0x06
175 #define		BPF_MISC	0x07
176 
177 /* ld/ldx fields */
178 #define BPF_SIZE(code)	((code) & 0x18)
179 #define		BPF_W		0x00
180 #define		BPF_H		0x08
181 #define		BPF_B		0x10
182 #define BPF_MODE(code)	((code) & 0xe0)
183 #define		BPF_IMM 	0x00
184 #define		BPF_ABS		0x20
185 #define		BPF_IND		0x40
186 #define		BPF_MEM		0x60
187 #define		BPF_LEN		0x80
188 #define		BPF_MSH		0xa0
189 
190 /* alu/jmp fields */
191 #define BPF_OP(code)	((code) & 0xf0)
192 #define		BPF_ADD		0x00
193 #define		BPF_SUB		0x10
194 #define		BPF_MUL		0x20
195 #define		BPF_DIV		0x30
196 #define		BPF_OR		0x40
197 #define		BPF_AND		0x50
198 #define		BPF_LSH		0x60
199 #define		BPF_RSH		0x70
200 #define		BPF_NEG		0x80
201 #define		BPF_JA		0x00
202 #define		BPF_JEQ		0x10
203 #define		BPF_JGT		0x20
204 #define		BPF_JGE		0x30
205 #define		BPF_JSET	0x40
206 #define BPF_SRC(code)	((code) & 0x08)
207 #define		BPF_K		0x00
208 #define		BPF_X		0x08
209 
210 /* ret - BPF_K and BPF_X also apply */
211 #define BPF_RVAL(code)	((code) & 0x18)
212 #define		BPF_A		0x10
213 
214 /* misc */
215 #define BPF_MISCOP(code) ((code) & 0xf8)
216 #define		BPF_TAX		0x00
217 #define		BPF_TXA		0x80
218 
219 /*
220  * The instruction data structure.
221  */
222 struct bpf_insn {
223 	u_short	code;
224 	u_char 	jt;
225 	u_char 	jf;
226 	long	k;
227 };
228 
229 /*
230  * Macros for insn array initializers.
231  */
232 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
233 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
234 
235 #ifdef KERNEL
236 extern u_int bpf_filter();
237 extern void bpfattach();
238 extern void bpf_tap();
239 extern void bpf_mtap();
240 #endif
241 
242 /*
243  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
244  */
245 #define BPF_MEMWORDS 16
246 
247 #endif /* !_NET_BPF_H_ */
248