xref: /freebsd/sys/net/bpf.h (revision 05c7a37afb48ddd5ee1bd921a5d46fe59cc70b15)
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  */
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. */
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  */
111 struct 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  */
202 struct 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
216 int	 bpf_validate __P((struct bpf_insn *, int));
217 void	 bpf_tap __P((struct ifnet *, u_char *, u_int));
218 void	 bpf_mtap __P((struct ifnet *, struct mbuf *));
219 void	 bpfattach __P((struct ifnet *, u_int, u_int));
220 void	 bpfilterattach __P((int));
221 u_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