xref: /netbsd-src/sys/net/bpf.h (revision ae1bfcddc410612bc8c58b807e1830becb69a24c)
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  *	from: @(#)bpf.h	8.1 (Berkeley) 6/10/93
39  *	$Id: bpf.h,v 1.5 1994/05/13 06:02:19 mycroft Exp $
40  */
41 
42 /*
43  * Alignment macros.  BPF_WORDALIGN rounds up to the next
44  * even multiple of BPF_ALIGNMENT.
45  */
46 #define BPF_ALIGNMENT sizeof(long)
47 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
48 
49 #define BPF_MAXINSNS 512
50 #define BPF_MAXBUFSIZE 0x8000
51 #define BPF_MINBUFSIZE 32
52 
53 /*
54  *  Structure for BIOCSETF.
55  */
56 struct bpf_program {
57 	u_int bf_len;
58 	struct bpf_insn *bf_insns;
59 };
60 
61 /*
62  * Struct returned by BIOCGSTATS.
63  */
64 struct bpf_stat {
65 	u_int bs_recv;		/* number of packets received */
66 	u_int bs_drop;		/* number of packets dropped */
67 };
68 
69 /*
70  * Struct return by BIOCVERSION.  This represents the version number of
71  * the filter language described by the instruction encodings below.
72  * bpf understands a program iff kernel_major == filter_major &&
73  * kernel_minor >= filter_minor, that is, if the value returned by the
74  * running kernel has the same major number and a minor number equal
75  * equal to or less than the filter being downloaded.  Otherwise, the
76  * results are undefined, meaning an error may be returned or packets
77  * may be accepted haphazardly.
78  * It has nothing to do with the source code version.
79  */
80 struct bpf_version {
81 	u_short bv_major;
82 	u_short bv_minor;
83 };
84 /* Current version number. */
85 #define BPF_MAJOR_VERSION 1
86 #define BPF_MINOR_VERSION 1
87 
88 /*
89  * BPF ioctls
90  *
91  * The first set is for compatibility with Sun's pcc style
92  * header files.  If your using gcc, we assume that you
93  * have run fixincludes so the latter set should work.
94  */
95 #if (defined(sun) || defined(ibm032)) && !defined(__GNUC__)
96 #define	BIOCGBLEN	_IOR(B,102, u_int)
97 #define	BIOCSBLEN	_IOWR(B,102, u_int)
98 #define	BIOCSETF	_IOW(B,103, struct bpf_program)
99 #define	BIOCFLUSH	_IO(B,104)
100 #define BIOCPROMISC	_IO(B,105)
101 #define	BIOCGDLT	_IOR(B,106, u_int)
102 #define BIOCGETIF	_IOR(B,107, struct ifreq)
103 #define BIOCSETIF	_IOW(B,108, struct ifreq)
104 #define BIOCSRTIMEOUT	_IOW(B,109, struct timeval)
105 #define BIOCGRTIMEOUT	_IOR(B,110, struct timeval)
106 #define BIOCGSTATS	_IOR(B,111, struct bpf_stat)
107 #define BIOCIMMEDIATE	_IOW(B,112, u_int)
108 #define BIOCVERSION	_IOR(B,113, struct bpf_version)
109 #else
110 #define	BIOCGBLEN	_IOR('B',102, u_int)
111 #define	BIOCSBLEN	_IOWR('B',102, u_int)
112 #define	BIOCSETF	_IOW('B',103, struct bpf_program)
113 #define	BIOCFLUSH	_IO('B',104)
114 #define BIOCPROMISC	_IO('B',105)
115 #define	BIOCGDLT	_IOR('B',106, u_int)
116 #define BIOCGETIF	_IOR('B',107, struct ifreq)
117 #define BIOCSETIF	_IOW('B',108, struct ifreq)
118 #define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
119 #define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
120 #define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
121 #define BIOCIMMEDIATE	_IOW('B',112, u_int)
122 #define BIOCVERSION	_IOR('B',113, struct bpf_version)
123 #endif
124 
125 /*
126  * Structure prepended to each packet.
127  */
128 struct bpf_hdr {
129 	struct timeval	bh_tstamp;	/* time stamp */
130 	u_long		bh_caplen;	/* length of captured portion */
131 	u_long		bh_datalen;	/* original length of packet */
132 	u_short		bh_hdrlen;	/* length of bpf header (this struct
133 					   plus alignment padding) */
134 };
135 /*
136  * Because the structure above is not a multiple of 4 bytes, some compilers
137  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
138  * Only the kernel needs to know about it; applications use bh_hdrlen.
139  */
140 #ifdef KERNEL
141 #define SIZEOF_BPF_HDR 18
142 #endif
143 
144 /*
145  * Data-link level type codes.
146  * Currently, only DLT_EN10MB and DLT_SLIP are supported.
147  */
148 #define DLT_NULL	0	/* no link-layer encapsulation */
149 #define DLT_EN10MB	1	/* Ethernet (10Mb) */
150 #define DLT_EN3MB	2	/* Experimental Ethernet (3Mb) */
151 #define DLT_AX25	3	/* Amateur Radio AX.25 */
152 #define DLT_PRONET	4	/* Proteon ProNET Token Ring */
153 #define DLT_CHAOS	5	/* Chaos */
154 #define DLT_IEEE802	6	/* IEEE 802 Networks */
155 #define DLT_ARCNET	7	/* ARCNET */
156 #define DLT_SLIP	8	/* Serial Line IP */
157 #define DLT_PPP		9	/* Point-to-point Protocol */
158 #define DLT_FDDI	10	/* FDDI */
159 
160 /*
161  * The instruction encondings.
162  */
163 /* instruction classes */
164 #define BPF_CLASS(code) ((code) & 0x07)
165 #define		BPF_LD		0x00
166 #define		BPF_LDX		0x01
167 #define		BPF_ST		0x02
168 #define		BPF_STX		0x03
169 #define		BPF_ALU		0x04
170 #define		BPF_JMP		0x05
171 #define		BPF_RET		0x06
172 #define		BPF_MISC	0x07
173 
174 /* ld/ldx fields */
175 #define BPF_SIZE(code)	((code) & 0x18)
176 #define		BPF_W		0x00
177 #define		BPF_H		0x08
178 #define		BPF_B		0x10
179 #define BPF_MODE(code)	((code) & 0xe0)
180 #define		BPF_IMM 	0x00
181 #define		BPF_ABS		0x20
182 #define		BPF_IND		0x40
183 #define		BPF_MEM		0x60
184 #define		BPF_LEN		0x80
185 #define		BPF_MSH		0xa0
186 
187 /* alu/jmp fields */
188 #define BPF_OP(code)	((code) & 0xf0)
189 #define		BPF_ADD		0x00
190 #define		BPF_SUB		0x10
191 #define		BPF_MUL		0x20
192 #define		BPF_DIV		0x30
193 #define		BPF_OR		0x40
194 #define		BPF_AND		0x50
195 #define		BPF_LSH		0x60
196 #define		BPF_RSH		0x70
197 #define		BPF_NEG		0x80
198 #define		BPF_JA		0x00
199 #define		BPF_JEQ		0x10
200 #define		BPF_JGT		0x20
201 #define		BPF_JGE		0x30
202 #define		BPF_JSET	0x40
203 #define BPF_SRC(code)	((code) & 0x08)
204 #define		BPF_K		0x00
205 #define		BPF_X		0x08
206 
207 /* ret - BPF_K and BPF_X also apply */
208 #define BPF_RVAL(code)	((code) & 0x18)
209 #define		BPF_A		0x10
210 
211 /* misc */
212 #define BPF_MISCOP(code) ((code) & 0xf8)
213 #define		BPF_TAX		0x00
214 #define		BPF_TXA		0x80
215 
216 /*
217  * The instruction data structure.
218  */
219 struct bpf_insn {
220 	u_short	code;
221 	u_char 	jt;
222 	u_char 	jf;
223 	long	k;
224 };
225 
226 /*
227  * Macros for insn array initializers.
228  */
229 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
230 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
231 
232 #ifdef KERNEL
233 int	 bpf_validate __P((struct bpf_insn *, int));
234 int	 bpfopen __P((dev_t, int));
235 int	 bpfclose __P((dev_t, int));
236 int	 bpfread __P((dev_t, struct uio *));
237 int	 bpfwrite __P((dev_t, struct uio *));
238 int	 bpfioctl __P((dev_t, int, caddr_t, int));
239 int	 bpf_select __P((dev_t, int, struct proc *));
240 void	 bpf_tap __P((caddr_t, u_char *, u_int));
241 void	 bpf_mtap __P((caddr_t, struct mbuf *));
242 void	 bpfattach __P((caddr_t *, struct ifnet *, u_int, u_int));
243 void	 bpfilterattach __P((int));
244 u_int	 bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int));
245 #endif
246 
247 /*
248  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
249  */
250 #define BPF_MEMWORDS 16
251 
252