xref: /netbsd/sys/net/bpf.h (revision bf9ec67e)
1 /*	$NetBSD: bpf.h,v 1.29 2001/12/14 23:30:02 thorpej 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	8.2 (Berkeley) 1/9/95
41  * @(#) Header: bpf.h,v 1.36 97/06/12 14:29:53 leres Exp  (LBL)
42  */
43 
44 #ifndef _NET_BPF_H_
45 #define _NET_BPF_H_
46 
47 #include <sys/time.h>
48 
49 /* BSD style release date */
50 #define BPF_RELEASE 199606
51 
52 typedef	int bpf_int32;
53 typedef	u_int bpf_u_int32;
54 
55 /*
56  * Alignment macros.  BPF_WORDALIGN rounds up to the next
57  * even multiple of BPF_ALIGNMENT.
58  */
59 #define BPF_ALIGNMENT sizeof(long)
60 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
61 
62 #define BPF_MAXINSNS 512
63 #define BPF_MAXBUFSIZE 0x8000
64 #define BPF_MINBUFSIZE 32
65 
66 /*
67  *  Structure for BIOCSETF.
68  */
69 struct bpf_program {
70 	u_int bf_len;
71 	struct bpf_insn *bf_insns;
72 };
73 
74 /*
75  * Struct returned by BIOCGSTATS.
76  */
77 struct bpf_stat {
78 	u_int bs_recv;		/* number of packets received */
79 	u_int bs_drop;		/* number of packets dropped */
80 };
81 
82 /*
83  * Struct return by BIOCVERSION.  This represents the version number of
84  * the filter language described by the instruction encodings below.
85  * bpf understands a program iff kernel_major == filter_major &&
86  * kernel_minor >= filter_minor, that is, if the value returned by the
87  * running kernel has the same major number and a minor number equal
88  * equal to or less than the filter being downloaded.  Otherwise, the
89  * results are undefined, meaning an error may be returned or packets
90  * may be accepted haphazardly.
91  * It has nothing to do with the source code version.
92  */
93 struct bpf_version {
94 	u_short bv_major;
95 	u_short bv_minor;
96 };
97 /* Current version number of filter architecture. */
98 #define BPF_MAJOR_VERSION 1
99 #define BPF_MINOR_VERSION 1
100 
101 /*
102  * BPF ioctls
103  *
104  * The first set is for compatibility with Sun's pcc style
105  * header files.  If your using gcc, we assume that you
106  * have run fixincludes so the latter set should work.
107  */
108 #if (defined(sun) || defined(ibm032)) && !defined(__GNUC__)
109 #define	BIOCGBLEN	_IOR(B,102, u_int)
110 #define	BIOCSBLEN	_IOWR(B,102, u_int)
111 #define	BIOCSETF	_IOW(B,103, struct bpf_program)
112 #define	BIOCFLUSH	_IO(B,104)
113 #define BIOCPROMISC	_IO(B,105)
114 #define	BIOCGDLT	_IOR(B,106, u_int)
115 #define BIOCGETIF	_IOR(B,107, struct ifreq)
116 #define BIOCSETIF	_IOW(B,108, struct ifreq)
117 #define BIOCSRTIMEOUT	_IOW(B,109, struct timeval)
118 #define BIOCGRTIMEOUT	_IOR(B,110, struct timeval)
119 #define BIOCGSTATS	_IOR(B,111, struct bpf_stat)
120 #define BIOCIMMEDIATE	_IOW(B,112, u_int)
121 #define BIOCVERSION	_IOR(B,113, struct bpf_version)
122 #define BIOCSTCPF	_IOW(B,114, struct bpf_program)
123 #define BIOCSUDPF	_IOW(B,115, struct bpf_program)
124 #define	BIOCGHDRCMPLT	_IOR(B,116, u_int)
125 #define	BIOCSHDRCMPLT	_IOW(B,117, u_int)
126 #else
127 #define	BIOCGBLEN	_IOR('B',102, u_int)
128 #define	BIOCSBLEN	_IOWR('B',102, u_int)
129 #define	BIOCSETF	_IOW('B',103, struct bpf_program)
130 #define	BIOCFLUSH	_IO('B',104)
131 #define BIOCPROMISC	_IO('B',105)
132 #define	BIOCGDLT	_IOR('B',106, u_int)
133 #define BIOCGETIF	_IOR('B',107, struct ifreq)
134 #define BIOCSETIF	_IOW('B',108, struct ifreq)
135 #define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
136 #define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
137 #define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
138 #define BIOCIMMEDIATE	_IOW('B',112, u_int)
139 #define BIOCVERSION	_IOR('B',113, struct bpf_version)
140 #define BIOCSTCPF	_IOW('B',114, struct bpf_program)
141 #define BIOCSUDPF	_IOW('B',115, struct bpf_program)
142 #define	BIOCGHDRCMPLT	_IOR('B',116, u_int)
143 #define	BIOCSHDRCMPLT	_IOW('B',117, u_int)
144 #endif
145 
146 /*
147  * Structure prepended to each packet.
148  */
149 struct bpf_hdr {
150 	struct timeval	bh_tstamp;	/* time stamp */
151 	u_int32_t	bh_caplen;	/* length of captured portion */
152 	u_int32_t	bh_datalen;	/* original length of packet */
153 	u_int16_t	bh_hdrlen;	/* length of bpf header (this struct
154 					   plus alignment padding) */
155 };
156 /*
157  * Because the structure above is not a multiple of 4 bytes, some compilers
158  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
159  * Only the kernel needs to know about it; applications use bh_hdrlen.
160  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
161  * XXX padding by using the size of the header data elements.  This is
162  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
163  */
164 #ifdef _KERNEL
165 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
166     defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
167     defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
168 #define SIZEOF_BPF_HDR 18
169 #else
170 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
171 #endif
172 #endif
173 
174 /* Pull in data-link level type codes. */
175 #include <net/dlt.h>
176 
177 /*
178  * The instruction encondings.
179  */
180 /* instruction classes */
181 #define BPF_CLASS(code) ((code) & 0x07)
182 #define		BPF_LD		0x00
183 #define		BPF_LDX		0x01
184 #define		BPF_ST		0x02
185 #define		BPF_STX		0x03
186 #define		BPF_ALU		0x04
187 #define		BPF_JMP		0x05
188 #define		BPF_RET		0x06
189 #define		BPF_MISC	0x07
190 
191 /* ld/ldx fields */
192 #define BPF_SIZE(code)	((code) & 0x18)
193 #define		BPF_W		0x00
194 #define		BPF_H		0x08
195 #define		BPF_B		0x10
196 #define BPF_MODE(code)	((code) & 0xe0)
197 #define		BPF_IMM 	0x00
198 #define		BPF_ABS		0x20
199 #define		BPF_IND		0x40
200 #define		BPF_MEM		0x60
201 #define		BPF_LEN		0x80
202 #define		BPF_MSH		0xa0
203 
204 /* alu/jmp fields */
205 #define BPF_OP(code)	((code) & 0xf0)
206 #define		BPF_ADD		0x00
207 #define		BPF_SUB		0x10
208 #define		BPF_MUL		0x20
209 #define		BPF_DIV		0x30
210 #define		BPF_OR		0x40
211 #define		BPF_AND		0x50
212 #define		BPF_LSH		0x60
213 #define		BPF_RSH		0x70
214 #define		BPF_NEG		0x80
215 #define		BPF_JA		0x00
216 #define		BPF_JEQ		0x10
217 #define		BPF_JGT		0x20
218 #define		BPF_JGE		0x30
219 #define		BPF_JSET	0x40
220 #define BPF_SRC(code)	((code) & 0x08)
221 #define		BPF_K		0x00
222 #define		BPF_X		0x08
223 
224 /* ret - BPF_K and BPF_X also apply */
225 #define BPF_RVAL(code)	((code) & 0x18)
226 #define		BPF_A		0x10
227 
228 /* misc */
229 #define BPF_MISCOP(code) ((code) & 0xf8)
230 #define		BPF_TAX		0x00
231 #define		BPF_TXA		0x80
232 
233 /*
234  * The instruction data structure.
235  */
236 struct bpf_insn {
237 	u_int16_t code;
238 	u_char 	  jt;
239 	u_char 	  jf;
240 	int32_t	  k;
241 };
242 
243 /*
244  * Macros for insn array initializers.
245  */
246 #define BPF_STMT(code, k) { (u_int16_t)(code), 0, 0, k }
247 #define BPF_JUMP(code, k, jt, jf) { (u_int16_t)(code), jt, jf, k }
248 
249 #ifdef _KERNEL
250 int	 bpf_validate __P((struct bpf_insn *, int));
251 void	 bpf_tap __P((caddr_t, u_char *, u_int));
252 void	 bpf_mtap __P((caddr_t, struct mbuf *));
253 void	 bpfattach __P((struct ifnet *, u_int, u_int));
254 void	 bpfdetach __P((struct ifnet *));
255 void	 bpf_change_type __P((struct ifnet *, u_int, u_int));
256 void	 bpfilterattach __P((int));
257 #endif
258 
259 u_int	 bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int));
260 
261 /*
262  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
263  */
264 #define BPF_MEMWORDS 16
265 
266 #endif /* _NET_BPF_H_ */
267