xref: /freebsd/sys/net/bpf.h (revision 4a0f765fbf09711e612e86fce8bb09ec43f482d9)
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  * $Id$
42  */
43 
44 #ifndef _NET_BPF_H_
45 #define _NET_BPF_H_
46 
47 /* BSD style release date */
48 #define	BPF_RELEASE 199606
49 
50 typedef	int32_t	  bpf_int32;
51 typedef	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  */
67 struct bpf_program {
68 	u_int bf_len;
69 	struct bpf_insn *bf_insns;
70 };
71 
72 /*
73  * Struct returned by BIOCGSTATS.
74  */
75 struct 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  */
91 struct 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  */
118 struct 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 18
132 #endif
133 
134 /*
135  * Data-link level type codes.
136  */
137 #define DLT_NULL	0	/* no link-layer encapsulation */
138 #define DLT_EN10MB	1	/* Ethernet (10Mb) */
139 #define DLT_EN3MB	2	/* Experimental Ethernet (3Mb) */
140 #define DLT_AX25	3	/* Amateur Radio AX.25 */
141 #define DLT_PRONET	4	/* Proteon ProNET Token Ring */
142 #define DLT_CHAOS	5	/* Chaos */
143 #define DLT_IEEE802	6	/* IEEE 802 Networks */
144 #define DLT_ARCNET	7	/* ARCNET */
145 #define DLT_SLIP	8	/* Serial Line IP */
146 #define DLT_PPP		9	/* Point-to-point Protocol */
147 #define DLT_FDDI	10	/* FDDI */
148 #define DLT_ATM_RFC1483	11	/* LLC/SNAP encapsulated atm */
149 
150 /*
151  * The instruction encodings.
152  */
153 /* instruction classes */
154 #define BPF_CLASS(code) ((code) & 0x07)
155 #define		BPF_LD		0x00
156 #define		BPF_LDX		0x01
157 #define		BPF_ST		0x02
158 #define		BPF_STX		0x03
159 #define		BPF_ALU		0x04
160 #define		BPF_JMP		0x05
161 #define		BPF_RET		0x06
162 #define		BPF_MISC	0x07
163 
164 /* ld/ldx fields */
165 #define BPF_SIZE(code)	((code) & 0x18)
166 #define		BPF_W		0x00
167 #define		BPF_H		0x08
168 #define		BPF_B		0x10
169 #define BPF_MODE(code)	((code) & 0xe0)
170 #define		BPF_IMM 	0x00
171 #define		BPF_ABS		0x20
172 #define		BPF_IND		0x40
173 #define		BPF_MEM		0x60
174 #define		BPF_LEN		0x80
175 #define		BPF_MSH		0xa0
176 
177 /* alu/jmp fields */
178 #define BPF_OP(code)	((code) & 0xf0)
179 #define		BPF_ADD		0x00
180 #define		BPF_SUB		0x10
181 #define		BPF_MUL		0x20
182 #define		BPF_DIV		0x30
183 #define		BPF_OR		0x40
184 #define		BPF_AND		0x50
185 #define		BPF_LSH		0x60
186 #define		BPF_RSH		0x70
187 #define		BPF_NEG		0x80
188 #define		BPF_JA		0x00
189 #define		BPF_JEQ		0x10
190 #define		BPF_JGT		0x20
191 #define		BPF_JGE		0x30
192 #define		BPF_JSET	0x40
193 #define BPF_SRC(code)	((code) & 0x08)
194 #define		BPF_K		0x00
195 #define		BPF_X		0x08
196 
197 /* ret - BPF_K and BPF_X also apply */
198 #define BPF_RVAL(code)	((code) & 0x18)
199 #define		BPF_A		0x10
200 
201 /* misc */
202 #define BPF_MISCOP(code) ((code) & 0xf8)
203 #define		BPF_TAX		0x00
204 #define		BPF_TXA		0x80
205 
206 /*
207  * The instruction data structure.
208  */
209 struct bpf_insn {
210 	u_short		code;
211 	u_char		jt;
212 	u_char		jf;
213 	bpf_u_int32	k;
214 };
215 
216 /*
217  * Macros for insn array initializers.
218  */
219 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
220 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
221 
222 #ifdef KERNEL
223 int	 bpf_validate __P((struct bpf_insn *, int));
224 void	 bpf_tap __P((struct ifnet *, u_char *, u_int));
225 void	 bpf_mtap __P((struct ifnet *, struct mbuf *));
226 void	 bpfattach __P((struct ifnet *, u_int, u_int));
227 void	 bpfilterattach __P((int));
228 u_int	 bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int));
229 #endif
230 
231 /*
232  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
233  */
234 #define BPF_MEMWORDS 16
235 
236 #endif
237