xref: /freebsd/sys/net/bpf.h (revision 0ea3482342b4d7d6e71f3007ce4dafe445c639fd)
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 1.6 1995/09/08 11:08:55 bde 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 /*
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 BIOCGRSIG	_IOR(B,114, u_int)
114 #define BIOCSRSIG	_IOW(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 BIOCGRSIG	_IOR('B',114, u_int)
130 #define BIOCSRSIG	_IOW('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_long		bh_caplen;	/* length of captured portion */
139 	u_long		bh_datalen;	/* original length of packet */
140 	u_short		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  */
148 #ifdef KERNEL
149 #define SIZEOF_BPF_HDR 18
150 #endif
151 
152 /*
153  * Data-link level type codes.
154  * Currently, only DLT_EN10MB and DLT_SLIP are supported.
155  */
156 #define DLT_NULL	0	/* no link-layer encapsulation */
157 #define DLT_EN10MB	1	/* Ethernet (10Mb) */
158 #define DLT_EN3MB	2	/* Experimental Ethernet (3Mb) */
159 #define DLT_AX25	3	/* Amateur Radio AX.25 */
160 #define DLT_PRONET	4	/* Proteon ProNET Token Ring */
161 #define DLT_CHAOS	5	/* Chaos */
162 #define DLT_IEEE802	6	/* IEEE 802 Networks */
163 #define DLT_ARCNET	7	/* ARCNET */
164 #define DLT_SLIP	8	/* Serial Line IP */
165 #define DLT_PPP		9	/* Point-to-point Protocol */
166 #define DLT_FDDI	10	/* FDDI */
167 
168 /*
169  * The instruction encondings.
170  */
171 /* instruction classes */
172 #define BPF_CLASS(code) ((code) & 0x07)
173 #define		BPF_LD		0x00
174 #define		BPF_LDX		0x01
175 #define		BPF_ST		0x02
176 #define		BPF_STX		0x03
177 #define		BPF_ALU		0x04
178 #define		BPF_JMP		0x05
179 #define		BPF_RET		0x06
180 #define		BPF_MISC	0x07
181 
182 /* ld/ldx fields */
183 #define BPF_SIZE(code)	((code) & 0x18)
184 #define		BPF_W		0x00
185 #define		BPF_H		0x08
186 #define		BPF_B		0x10
187 #define BPF_MODE(code)	((code) & 0xe0)
188 #define		BPF_IMM 	0x00
189 #define		BPF_ABS		0x20
190 #define		BPF_IND		0x40
191 #define		BPF_MEM		0x60
192 #define		BPF_LEN		0x80
193 #define		BPF_MSH		0xa0
194 
195 /* alu/jmp fields */
196 #define BPF_OP(code)	((code) & 0xf0)
197 #define		BPF_ADD		0x00
198 #define		BPF_SUB		0x10
199 #define		BPF_MUL		0x20
200 #define		BPF_DIV		0x30
201 #define		BPF_OR		0x40
202 #define		BPF_AND		0x50
203 #define		BPF_LSH		0x60
204 #define		BPF_RSH		0x70
205 #define		BPF_NEG		0x80
206 #define		BPF_JA		0x00
207 #define		BPF_JEQ		0x10
208 #define		BPF_JGT		0x20
209 #define		BPF_JGE		0x30
210 #define		BPF_JSET	0x40
211 #define BPF_SRC(code)	((code) & 0x08)
212 #define		BPF_K		0x00
213 #define		BPF_X		0x08
214 
215 /* ret - BPF_K and BPF_X also apply */
216 #define BPF_RVAL(code)	((code) & 0x18)
217 #define		BPF_A		0x10
218 
219 /* misc */
220 #define BPF_MISCOP(code) ((code) & 0xf8)
221 #define		BPF_TAX		0x00
222 #define		BPF_TXA		0x80
223 
224 /*
225  * The instruction data structure.
226  */
227 struct bpf_insn {
228 	u_short	code;
229 	u_char 	jt;
230 	u_char 	jf;
231 	long	k;
232 };
233 
234 /*
235  * Macros for insn array initializers.
236  */
237 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
238 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
239 
240 #ifdef KERNEL
241 int	 bpf_validate __P((struct bpf_insn *, int));
242 void	 bpf_tap __P((caddr_t, u_char *, u_int));
243 void	 bpf_mtap __P((caddr_t, struct mbuf *));
244 void	 bpfattach __P((caddr_t *, struct ifnet *, u_int, u_int));
245 void	 bpfilterattach __P((int));
246 u_int	 bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int));
247 #endif
248 
249 /*
250  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
251  */
252 #define BPF_MEMWORDS 16
253 
254 #endif
255