xref: /dragonfly/sys/net/bpf.h (revision dcb5d66b)
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. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *      @(#)bpf.h	8.1 (Berkeley) 6/10/93
35  *	@(#)bpf.h	1.34 (LBL)     6/16/96
36  *
37  * $FreeBSD: src/sys/net/bpf.h,v 1.21.2.4 2002/07/05 14:40:00 fenner Exp $
38  */
39 
40 #ifndef _NET_BPF_H_
41 #define _NET_BPF_H_
42 
43 #ifndef _SYS_PARAM_H_
44 #include <sys/param.h>
45 #endif
46 #ifndef _SYS_TIME_H_
47 #include <sys/time.h>
48 #endif
49 #ifndef _SYS_IOCCOM_H_
50 #include <sys/ioccom.h>
51 #endif
52 
53 __BEGIN_DECLS
54 
55 #define BPF_MAX_CLONES	128
56 
57 /* BSD style release date */
58 #define	BPF_RELEASE 199606
59 
60 typedef	int32_t	  bpf_int32;
61 typedef	u_int32_t bpf_u_int32;
62 
63 /*
64  * Alignment macros.  BPF_WORDALIGN rounds up to the next
65  * even multiple of BPF_ALIGNMENT.
66  */
67 #define BPF_ALIGNMENT sizeof(long)
68 #define BPF_WORDALIGN(x) roundup2(x, BPF_ALIGNMENT)
69 
70 #define BPF_MAXINSNS 512
71 #define BPF_MAXBUFSIZE 0x80000
72 #define BPF_DEFAULTBUFSIZE 4096
73 #define BPF_MINBUFSIZE 32
74 
75 /*
76  *  Structure for BIOCSETF.
77  */
78 struct bpf_program {
79 	u_int bf_len;
80 	struct bpf_insn *bf_insns;
81 };
82 
83 /*
84  * Struct returned by BIOCGSTATS.
85  */
86 struct bpf_stat {
87 	u_int bs_recv;		/* number of packets received */
88 	u_int bs_drop;		/* number of packets dropped */
89 };
90 
91 /*
92  * Struct return by BIOCVERSION.  This represents the version number of
93  * the filter language described by the instruction encodings below.
94  * bpf understands a program iff kernel_major == filter_major &&
95  * kernel_minor >= filter_minor, that is, if the value returned by the
96  * running kernel has the same major number and a minor number equal
97  * equal to or less than the filter being downloaded.  Otherwise, the
98  * results are undefined, meaning an error may be returned or packets
99  * may be accepted haphazardly.
100  * It has nothing to do with the source code version.
101  */
102 struct bpf_version {
103 	u_short bv_major;
104 	u_short bv_minor;
105 };
106 /* Current version number of filter architecture. */
107 #define BPF_MAJOR_VERSION 1
108 #define BPF_MINOR_VERSION 1
109 
110 #define	BIOCGBLEN	_IOR('B',102, u_int)
111 #define	BIOCSBLEN	_IOWR('B',102, u_int)
112 #define	BIOCSETF	_IOW('B',103, struct bpf_program)
113 #define	BIOCFLUSH	_IO('B',104)
114 #define BIOCPROMISC	_IO('B',105)
115 #define	BIOCGDLT	_IOR('B',106, u_int)
116 #define BIOCGETIF	_IOR('B',107, struct ifreq)
117 #define BIOCSETIF	_IOW('B',108, struct ifreq)
118 #define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
119 #define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
120 #define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
121 #define BIOCIMMEDIATE	_IOW('B',112, u_int)
122 #define BIOCVERSION	_IOR('B',113, struct bpf_version)
123 #define BIOCGRSIG	_IOR('B',114, u_int)
124 #define BIOCSRSIG	_IOW('B',115, u_int)
125 #define BIOCGHDRCMPLT	_IOR('B',116, u_int)
126 #define BIOCSHDRCMPLT	_IOW('B',117, u_int)
127 #define BIOCGSEESENT	_IOR('B',118, u_int)
128 #define BIOCSSEESENT	_IOW('B',119, u_int)
129 #define	BIOCSDLT	_IOW('B',120, u_int)
130 #define	BIOCGDLTLIST	_IOWR('B',121, struct bpf_dltlist)
131 #define	BIOCLOCK	_IO('B', 122)
132 #define	BIOCSETWF	_IOW('B',123, struct bpf_program)
133 #define BIOCGFEEDBACK	 _IOR('B',124, u_int)
134 #define BIOCSFEEDBACK	 _IOW('B',125, u_int)
135 #define BIOCFEEDBACK     BIOCSFEEDBACK		/* FreeBSD name */
136 
137 /*
138  * Structure prepended to each packet.
139  */
140 struct bpf_hdr {
141 	struct timeval	bh_tstamp;	/* time stamp */
142 	bpf_u_int32	bh_caplen;	/* length of captured portion */
143 	bpf_u_int32	bh_datalen;	/* original length of packet */
144 	u_short		bh_hdrlen;	/* length of bpf header (this struct
145 					   plus alignment padding) */
146 };
147 /*
148  * Because the structure above is not a multiple of 4 bytes, some compilers
149  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
150  * Only the kernel needs to know about it; applications use bh_hdrlen.
151  */
152 #ifdef _KERNEL
153 #define	SIZEOF_BPF_HDR	(sizeof(struct bpf_hdr) <= 20 ? 18 : \
154     sizeof(struct bpf_hdr))
155 #endif
156 
157 #ifndef _NET_DLT_H
158 #include <net/dlt.h>
159 #endif
160 
161 /*
162  * The instruction encodings.
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_MOD		0x90
200 #define		BPF_XOR		0xa0
201 #define		BPF_JA		0x00
202 #define		BPF_JEQ		0x10
203 #define		BPF_JGT		0x20
204 #define		BPF_JGE		0x30
205 #define		BPF_JSET	0x40
206 #define BPF_SRC(code)	((code) & 0x08)
207 #define		BPF_K		0x00
208 #define		BPF_X		0x08
209 
210 /* ret - BPF_K and BPF_X also apply */
211 #define BPF_RVAL(code)	((code) & 0x18)
212 #define		BPF_A		0x10
213 
214 /* misc */
215 #define BPF_MISCOP(code) ((code) & 0xf8)
216 #define		BPF_TAX		0x00
217 #define		BPF_TXA		0x80
218 
219 /*
220  * The instruction data structure.
221  */
222 struct bpf_insn {
223 	u_short		code;
224 	u_char		jt;
225 	u_char		jf;
226 	bpf_u_int32	k;
227 };
228 
229 /*
230  * Macros for insn array initializers.
231  */
232 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
233 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
234 
235 /*
236  * Structure to retrieve available DLTs for the interface.
237  */
238 struct bpf_dltlist {
239 	u_int	bfl_len;	/* number of bfd_list array */
240 	u_int	*bfl_list;	/* array of DLTs */
241 };
242 
243 #ifdef _KERNEL
244 
245 struct bpf_if;
246 struct ifnet;
247 struct mbuf;
248 
249 int	 bpf_validate(const struct bpf_insn *, int);
250 void	 bpf_tap(struct bpf_if *, u_char *, u_int);
251 void	 bpf_mtap(struct bpf_if *, struct mbuf *);
252 void	 bpf_mtap_family(struct bpf_if *, struct mbuf *m, __uint8_t family);
253 void	 bpf_mtap_hdr(struct bpf_if *, caddr_t, u_int, struct mbuf *, u_int);
254 void	 bpf_ptap(struct bpf_if *, struct mbuf *, const void *, u_int);
255 void	 bpfattach(struct ifnet *, u_int, u_int);
256 void	 bpfattach_dlt(struct ifnet *, u_int, u_int, struct bpf_if **);
257 void	 bpfdetach(struct ifnet *);
258 void	 bpf_gettoken(void);
259 void	 bpf_reltoken(void);
260 
261 u_int	 bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
262 
263 #define	BPF_TAP(_ifp,_pkt,_pktlen) do {					\
264 	if ((_ifp)->if_bpf) {						\
265 		bpf_gettoken();						\
266 		if ((_ifp)->if_bpf)					\
267 			bpf_tap((_ifp)->if_bpf, (_pkt), (_pktlen));	\
268 		bpf_reltoken();						\
269 	}								\
270 } while (0)
271 
272 #define	BPF_MTAP(_ifp,_m) do {						\
273 	if ((_ifp)->if_bpf) {						\
274 		bpf_gettoken();						\
275 		if ((_ifp)->if_bpf)					\
276 			bpf_mtap((_ifp)->if_bpf, (_m));                 \
277 		bpf_reltoken();						\
278 	}								\
279 } while (0)
280 
281 #endif	/* _KERNEL */
282 
283 /*
284  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
285  */
286 #define BPF_MEMWORDS 16
287 
288 __END_DECLS
289 
290 #endif	/* !_NET_BPF_H_ */
291