bpf.h revision 1817 
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 * $Id$
41 */
42
43/*
44 * Alignment macros.  BPF_WORDALIGN rounds up to the next
45 * even multiple of BPF_ALIGNMENT.
46 */
47#define BPF_ALIGNMENT sizeof(long)
48#define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
49
50#define BPF_MAXINSNS 512
51#define BPF_MAXBUFSIZE 0x8000
52#define BPF_MINBUFSIZE 32
53
54/*
55 *  Structure for BIOCSETF.
56 */
57struct bpf_program {
58	u_int bf_len;
59	struct bpf_insn *bf_insns;
60};
61
62/*
63 * Struct returned by BIOCGSTATS.
64 */
65struct bpf_stat {
66	u_int bs_recv;		/* number of packets received */
67	u_int bs_drop;		/* number of packets dropped */
68};
69
70/*
71 * Struct return by BIOCVERSION.  This represents the version number of
72 * the filter language described by the instruction encodings below.
73 * bpf understands a program iff kernel_major == filter_major &&
74 * kernel_minor >= filter_minor, that is, if the value returned by the
75 * running kernel has the same major number and a minor number equal
76 * equal to or less than the filter being downloaded.  Otherwise, the
77 * results are undefined, meaning an error may be returned or packets
78 * may be accepted haphazardly.
79 * It has nothing to do with the source code version.
80 */
81struct bpf_version {
82	u_short bv_major;
83	u_short bv_minor;
84};
85/* Current version number. */
86#define BPF_MAJOR_VERSION 1
87#define BPF_MINOR_VERSION 1
88
89/*
90 * BPF ioctls
91 *
92 * The first set is for compatibility with Sun's pcc style
93 * header files.  If your using gcc, we assume that you
94 * have run fixincludes so the latter set should work.
95 */
96#if (defined(sun) || defined(ibm032)) && !defined(__GNUC__)
97#define	BIOCGBLEN	_IOR(B,102, u_int)
98#define	BIOCSBLEN	_IOWR(B,102, u_int)
99#define	BIOCSETF	_IOW(B,103, struct bpf_program)
100#define	BIOCFLUSH	_IO(B,104)
101#define BIOCPROMISC	_IO(B,105)
102#define	BIOCGDLT	_IOR(B,106, u_int)
103#define BIOCGETIF	_IOR(B,107, struct ifreq)
104#define BIOCSETIF	_IOW(B,108, struct ifreq)
105#define BIOCSRTIMEOUT	_IOW(B,109, struct timeval)
106#define BIOCGRTIMEOUT	_IOR(B,110, struct timeval)
107#define BIOCGSTATS	_IOR(B,111, struct bpf_stat)
108#define BIOCIMMEDIATE	_IOW(B,112, u_int)
109#define BIOCVERSION	_IOR(B,113, struct bpf_version)
110#else
111#define	BIOCGBLEN	_IOR('B',102, u_int)
112#define	BIOCSBLEN	_IOWR('B',102, u_int)
113#define	BIOCSETF	_IOW('B',103, struct bpf_program)
114#define	BIOCFLUSH	_IO('B',104)
115#define BIOCPROMISC	_IO('B',105)
116#define	BIOCGDLT	_IOR('B',106, u_int)
117#define BIOCGETIF	_IOR('B',107, struct ifreq)
118#define BIOCSETIF	_IOW('B',108, struct ifreq)
119#define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
120#define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
121#define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
122#define BIOCIMMEDIATE	_IOW('B',112, u_int)
123#define BIOCVERSION	_IOR('B',113, struct bpf_version)
124#endif
125
126/*
127 * Structure prepended to each packet.
128 */
129struct bpf_hdr {
130	struct timeval	bh_tstamp;	/* time stamp */
131	u_long		bh_caplen;	/* length of captured portion */
132	u_long		bh_datalen;	/* original length of packet */
133	u_short		bh_hdrlen;	/* length of bpf header (this struct
134					   plus alignment padding) */
135};
136/*
137 * Because the structure above is not a multiple of 4 bytes, some compilers
138 * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
139 * Only the kernel needs to know about it; applications use bh_hdrlen.
140 */
141#ifdef KERNEL
142#define SIZEOF_BPF_HDR 18
143#endif
144
145/*
146 * Data-link level type codes.
147 * Currently, only DLT_EN10MB and DLT_SLIP are supported.
148 */
149#define DLT_NULL	0	/* no link-layer encapsulation */
150#define DLT_EN10MB	1	/* Ethernet (10Mb) */
151#define DLT_EN3MB	2	/* Experimental Ethernet (3Mb) */
152#define DLT_AX25	3	/* Amateur Radio AX.25 */
153#define DLT_PRONET	4	/* Proteon ProNET Token Ring */
154#define DLT_CHAOS	5	/* Chaos */
155#define DLT_IEEE802	6	/* IEEE 802 Networks */
156#define DLT_ARCNET	7	/* ARCNET */
157#define DLT_SLIP	8	/* Serial Line IP */
158#define DLT_PPP		9	/* Point-to-point Protocol */
159#define DLT_FDDI	10	/* FDDI */
160
161/*
162 * The instruction encondings.
163 */
164/* instruction classes */
165#define BPF_CLASS(code) ((code) & 0x07)
166#define		BPF_LD		0x00
167#define		BPF_LDX		0x01
168#define		BPF_ST		0x02
169#define		BPF_STX		0x03
170#define		BPF_ALU		0x04
171#define		BPF_JMP		0x05
172#define		BPF_RET		0x06
173#define		BPF_MISC	0x07
174
175/* ld/ldx fields */
176#define BPF_SIZE(code)	((code) & 0x18)
177#define		BPF_W		0x00
178#define		BPF_H		0x08
179#define		BPF_B		0x10
180#define BPF_MODE(code)	((code) & 0xe0)
181#define		BPF_IMM 	0x00
182#define		BPF_ABS		0x20
183#define		BPF_IND		0x40
184#define		BPF_MEM		0x60
185#define		BPF_LEN		0x80
186#define		BPF_MSH		0xa0
187
188/* alu/jmp fields */
189#define BPF_OP(code)	((code) & 0xf0)
190#define		BPF_ADD		0x00
191#define		BPF_SUB		0x10
192#define		BPF_MUL		0x20
193#define		BPF_DIV		0x30
194#define		BPF_OR		0x40
195#define		BPF_AND		0x50
196#define		BPF_LSH		0x60
197#define		BPF_RSH		0x70
198#define		BPF_NEG		0x80
199#define		BPF_JA		0x00
200#define		BPF_JEQ		0x10
201#define		BPF_JGT		0x20
202#define		BPF_JGE		0x30
203#define		BPF_JSET	0x40
204#define BPF_SRC(code)	((code) & 0x08)
205#define		BPF_K		0x00
206#define		BPF_X		0x08
207
208/* ret - BPF_K and BPF_X also apply */
209#define BPF_RVAL(code)	((code) & 0x18)
210#define		BPF_A		0x10
211
212/* misc */
213#define BPF_MISCOP(code) ((code) & 0xf8)
214#define		BPF_TAX		0x00
215#define		BPF_TXA		0x80
216
217/*
218 * The instruction data structure.
219 */
220struct bpf_insn {
221	u_short	code;
222	u_char 	jt;
223	u_char 	jf;
224	long	k;
225};
226
227/*
228 * Macros for insn array initializers.
229 */
230#define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
231#define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
232
233#ifdef KERNEL
234int	 bpf_validate __P((struct bpf_insn *, int));
235int	 bpfopen __P((dev_t, int));
236int	 bpfclose __P((dev_t, int));
237int	 bpfread __P((dev_t, struct uio *));
238int	 bpfwrite __P((dev_t, struct uio *));
239int	 bpfioctl __P((dev_t, int, caddr_t, int));
240int	 bpf_select __P((dev_t, int, struct proc *));
241void	 bpf_tap __P((caddr_t, u_char *, u_int));
242void	 bpf_mtap __P((caddr_t, struct mbuf *));
243void	 bpfattach __P((caddr_t *, struct ifnet *, u_int, u_int));
244void	 bpfilterattach __P((int));
245u_int	 bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int));
246#endif
247
248/*
249 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
250 */
251#define BPF_MEMWORDS 16
252
253