xref: /netbsd-src/sys/net/bpf.h (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: bpf.h,v 1.14 1996/05/02 00:57:28 cgd Exp $	*/
2 
3 /*
4  * Copyright (c) 1990, 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from the Stanford/CMU enet packet filter,
8  * (net/enet.c) distributed as part of 4.3BSD, and code contributed
9  * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
10  * Berkeley Laboratory.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *	This product includes software developed by the University of
23  *	California, Berkeley and its contributors.
24  * 4. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  *
40  *	@(#)bpf.h	8.1 (Berkeley) 6/10/93
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  */
60 struct bpf_program {
61 	u_int bf_len;
62 	struct bpf_insn *bf_insns;
63 };
64 
65 /*
66  * Struct returned by BIOCGSTATS.
67  */
68 struct 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  */
84 struct bpf_version {
85 	u_short bv_major;
86 	u_short bv_minor;
87 };
88 /* Current version number of filter architecture. */
89 #define BPF_MAJOR_VERSION 1
90 #define BPF_MINOR_VERSION 1
91 
92 /*
93  * BPF ioctls
94  *
95  * The first set is for compatibility with Sun's pcc style
96  * header files.  If your using gcc, we assume that you
97  * have run fixincludes so the latter set should work.
98  */
99 #if (defined(sun) || defined(ibm032)) && !defined(__GNUC__)
100 #define	BIOCGBLEN	_IOR(B,102, u_int)
101 #define	BIOCSBLEN	_IOWR(B,102, u_int)
102 #define	BIOCSETF	_IOW(B,103, struct bpf_program)
103 #define	BIOCFLUSH	_IO(B,104)
104 #define BIOCPROMISC	_IO(B,105)
105 #define	BIOCGDLT	_IOR(B,106, u_int)
106 #define BIOCGETIF	_IOR(B,107, struct ifreq)
107 #define BIOCSETIF	_IOW(B,108, struct ifreq)
108 #define BIOCSRTIMEOUT	_IOW(B,109, struct timeval)
109 #define BIOCGRTIMEOUT	_IOR(B,110, struct timeval)
110 #define BIOCGSTATS	_IOR(B,111, struct bpf_stat)
111 #define BIOCIMMEDIATE	_IOW(B,112, u_int)
112 #define BIOCVERSION	_IOR(B,113, struct bpf_version)
113 #define BIOCSRSIG	_IOW(B,114, u_int)
114 #define BIOCGRSIG	_IOR(B,115, u_int)
115 #else
116 #define	BIOCGBLEN	_IOR('B',102, u_int)
117 #define	BIOCSBLEN	_IOWR('B',102, u_int)
118 #define	BIOCSETF	_IOW('B',103, struct bpf_program)
119 #define	BIOCFLUSH	_IO('B',104)
120 #define BIOCPROMISC	_IO('B',105)
121 #define	BIOCGDLT	_IOR('B',106, u_int)
122 #define BIOCGETIF	_IOR('B',107, struct ifreq)
123 #define BIOCSETIF	_IOW('B',108, struct ifreq)
124 #define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
125 #define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
126 #define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
127 #define BIOCIMMEDIATE	_IOW('B',112, u_int)
128 #define BIOCVERSION	_IOR('B',113, struct bpf_version)
129 #define BIOCSRSIG	_IOW('B',114, u_int)
130 #define BIOCGRSIG	_IOR('B',115, u_int)
131 #endif
132 
133 /*
134  * Structure prepended to each packet.
135  */
136 struct bpf_hdr {
137 	struct timeval	bh_tstamp;	/* time stamp */
138 	u_int32_t	bh_caplen;	/* length of captured portion */
139 	u_int32_t	bh_datalen;	/* original length of packet */
140 	u_int16_t	bh_hdrlen;	/* length of bpf header (this struct
141 					   plus alignment padding) */
142 };
143 /*
144  * Because the structure above is not a multiple of 4 bytes, some compilers
145  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
146  * Only the kernel needs to know about it; applications use bh_hdrlen.
147  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
148  * XXX padding by using the size of the header data elements.  This is
149  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
150  */
151 #ifdef _KERNEL
152 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
153     defined(__mips__) || defined(__ns32k__) || defined(__sparc__) || \
154     defined(__vax__)
155 #define SIZEOF_BPF_HDR 18
156 #else
157 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
158 #endif
159 #endif
160 
161 /*
162  * Data-link level type codes.
163  */
164 #define DLT_NULL	0	/* no link-layer encapsulation */
165 #define DLT_EN10MB	1	/* Ethernet (10Mb) */
166 #define DLT_EN3MB	2	/* Experimental Ethernet (3Mb) */
167 #define DLT_AX25	3	/* Amateur Radio AX.25 */
168 #define DLT_PRONET	4	/* Proteon ProNET Token Ring */
169 #define DLT_CHAOS	5	/* Chaos */
170 #define DLT_IEEE802	6	/* IEEE 802 Networks */
171 #define DLT_ARCNET	7	/* ARCNET */
172 #define DLT_SLIP	8	/* Serial Line IP */
173 #define DLT_PPP		9	/* Point-to-point Protocol */
174 #define DLT_FDDI	10	/* FDDI */
175 
176 /*
177  * The instruction encondings.
178  */
179 /* instruction classes */
180 #define BPF_CLASS(code) ((code) & 0x07)
181 #define		BPF_LD		0x00
182 #define		BPF_LDX		0x01
183 #define		BPF_ST		0x02
184 #define		BPF_STX		0x03
185 #define		BPF_ALU		0x04
186 #define		BPF_JMP		0x05
187 #define		BPF_RET		0x06
188 #define		BPF_MISC	0x07
189 
190 /* ld/ldx fields */
191 #define BPF_SIZE(code)	((code) & 0x18)
192 #define		BPF_W		0x00
193 #define		BPF_H		0x08
194 #define		BPF_B		0x10
195 #define BPF_MODE(code)	((code) & 0xe0)
196 #define		BPF_IMM 	0x00
197 #define		BPF_ABS		0x20
198 #define		BPF_IND		0x40
199 #define		BPF_MEM		0x60
200 #define		BPF_LEN		0x80
201 #define		BPF_MSH		0xa0
202 
203 /* alu/jmp fields */
204 #define BPF_OP(code)	((code) & 0xf0)
205 #define		BPF_ADD		0x00
206 #define		BPF_SUB		0x10
207 #define		BPF_MUL		0x20
208 #define		BPF_DIV		0x30
209 #define		BPF_OR		0x40
210 #define		BPF_AND		0x50
211 #define		BPF_LSH		0x60
212 #define		BPF_RSH		0x70
213 #define		BPF_NEG		0x80
214 #define		BPF_JA		0x00
215 #define		BPF_JEQ		0x10
216 #define		BPF_JGT		0x20
217 #define		BPF_JGE		0x30
218 #define		BPF_JSET	0x40
219 #define BPF_SRC(code)	((code) & 0x08)
220 #define		BPF_K		0x00
221 #define		BPF_X		0x08
222 
223 /* ret - BPF_K and BPF_X also apply */
224 #define BPF_RVAL(code)	((code) & 0x18)
225 #define		BPF_A		0x10
226 
227 /* misc */
228 #define BPF_MISCOP(code) ((code) & 0xf8)
229 #define		BPF_TAX		0x00
230 #define		BPF_TXA		0x80
231 
232 /*
233  * The instruction data structure.
234  */
235 struct bpf_insn {
236 	u_int16_t code;
237 	u_char 	  jt;
238 	u_char 	  jf;
239 	int32_t	  k;
240 };
241 
242 /*
243  * Macros for insn array initializers.
244  */
245 #define BPF_STMT(code, k) { (u_int16_t)(code), 0, 0, k }
246 #define BPF_JUMP(code, k, jt, jf) { (u_int16_t)(code), jt, jf, k }
247 
248 #ifdef _KERNEL
249 int	 bpf_validate __P((struct bpf_insn *, int));
250 void	 bpf_tap __P((caddr_t, u_char *, u_int));
251 void	 bpf_mtap __P((caddr_t, struct mbuf *));
252 void	 bpfattach __P((caddr_t *, struct ifnet *, u_int, u_int));
253 void	 bpfilterattach __P((int));
254 u_int	 bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int));
255 #endif
256 
257 /*
258  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
259  */
260 #define BPF_MEMWORDS 16
261 
262 #endif /* _NET_BPF_H_ */
263