xref: /dragonfly/sys/net/bpf.h (revision 63e03116)
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 #include <sys/param.h>
44 #include <sys/time.h>
45 #include <sys/ioccom.h>
46 
47 __BEGIN_DECLS
48 
49 #define BPF_MAX_CLONES	128
50 
51 /* BSD style release date */
52 #define	BPF_RELEASE 199606
53 
54 typedef	int32_t	  bpf_int32;
55 typedef	u_int32_t bpf_u_int32;
56 
57 /*
58  * Alignment macros.  BPF_WORDALIGN rounds up to the next
59  * even multiple of BPF_ALIGNMENT.
60  */
61 #define BPF_ALIGNMENT sizeof(long)
62 #define BPF_WORDALIGN(x) roundup2(x, BPF_ALIGNMENT)
63 
64 #define BPF_MAXINSNS 512
65 #define BPF_MAXBUFSIZE 0x80000
66 #define BPF_DEFAULTBUFSIZE 4096
67 #define BPF_MINBUFSIZE 32
68 
69 /*
70  *  Structure for BIOCSETF.
71  */
72 struct bpf_program {
73 	u_int bf_len;
74 	struct bpf_insn *bf_insns;
75 };
76 
77 /*
78  * Struct returned by BIOCGSTATS.
79  */
80 struct bpf_stat {
81 	u_int bs_recv;		/* number of packets received */
82 	u_int bs_drop;		/* number of packets dropped */
83 };
84 
85 /*
86  * Struct return by BIOCVERSION.  This represents the version number of
87  * the filter language described by the instruction encodings below.
88  * bpf understands a program iff kernel_major == filter_major &&
89  * kernel_minor >= filter_minor, that is, if the value returned by the
90  * running kernel has the same major number and a minor number equal
91  * equal to or less than the filter being downloaded.  Otherwise, the
92  * results are undefined, meaning an error may be returned or packets
93  * may be accepted haphazardly.
94  * It has nothing to do with the source code version.
95  */
96 struct bpf_version {
97 	u_short bv_major;
98 	u_short bv_minor;
99 };
100 /* Current version number of filter architecture. */
101 #define BPF_MAJOR_VERSION 1
102 #define BPF_MINOR_VERSION 1
103 
104 #define	BIOCGBLEN	_IOR('B',102, u_int)
105 #define	BIOCSBLEN	_IOWR('B',102, u_int)
106 #define	BIOCSETF	_IOW('B',103, struct bpf_program)
107 #define	BIOCFLUSH	_IO('B',104)
108 #define BIOCPROMISC	_IO('B',105)
109 #define	BIOCGDLT	_IOR('B',106, u_int)
110 #define BIOCGETIF	_IOR('B',107, struct ifreq)
111 #define BIOCSETIF	_IOW('B',108, struct ifreq)
112 #define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
113 #define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
114 #define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
115 #define BIOCIMMEDIATE	_IOW('B',112, u_int)
116 #define BIOCVERSION	_IOR('B',113, struct bpf_version)
117 #define BIOCGRSIG	_IOR('B',114, u_int)
118 #define BIOCSRSIG	_IOW('B',115, u_int)
119 #define BIOCGHDRCMPLT	_IOR('B',116, u_int)
120 #define BIOCSHDRCMPLT	_IOW('B',117, u_int)
121 #define BIOCGSEESENT	_IOR('B',118, u_int)
122 #define BIOCSSEESENT	_IOW('B',119, u_int)
123 #define	BIOCSDLT	_IOW('B',120, u_int)
124 #define	BIOCGDLTLIST	_IOWR('B',121, struct bpf_dltlist)
125 #define	BIOCLOCK	_IO('B', 122)
126 #define	BIOCSETWF	_IOW('B',123, struct bpf_program)
127 #define BIOCGFEEDBACK	 _IOR('B',124, u_int)
128 #define BIOCSFEEDBACK	 _IOW('B',125, u_int)
129 #define BIOCFEEDBACK     BIOCSFEEDBACK		/* FreeBSD name */
130 
131 /*
132  * Structure prepended to each packet.
133  */
134 struct bpf_hdr {
135 	struct timeval	bh_tstamp;	/* time stamp */
136 	bpf_u_int32	bh_caplen;	/* length of captured portion */
137 	bpf_u_int32	bh_datalen;	/* original length of packet */
138 	u_short		bh_hdrlen;	/* length of bpf header (this struct
139 					   plus alignment padding) */
140 };
141 /*
142  * Because the structure above is not a multiple of 4 bytes, some compilers
143  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
144  * Only the kernel needs to know about it; applications use bh_hdrlen.
145  */
146 #ifdef _KERNEL
147 #define	SIZEOF_BPF_HDR	(sizeof(struct bpf_hdr) <= 20 ? 18 : \
148     sizeof(struct bpf_hdr))
149 #endif
150 
151 /* Pull in data-link level type codes. */
152 #include <net/dlt.h>
153 
154 /*
155  * The instruction encodings.
156  */
157 /* instruction classes */
158 #define BPF_CLASS(code) ((code) & 0x07)
159 #define		BPF_LD		0x00
160 #define		BPF_LDX		0x01
161 #define		BPF_ST		0x02
162 #define		BPF_STX		0x03
163 #define		BPF_ALU		0x04
164 #define		BPF_JMP		0x05
165 #define		BPF_RET		0x06
166 #define		BPF_MISC	0x07
167 
168 /* ld/ldx fields */
169 #define BPF_SIZE(code)	((code) & 0x18)
170 #define		BPF_W		0x00
171 #define		BPF_H		0x08
172 #define		BPF_B		0x10
173 #define BPF_MODE(code)	((code) & 0xe0)
174 #define		BPF_IMM		0x00
175 #define		BPF_ABS		0x20
176 #define		BPF_IND		0x40
177 #define		BPF_MEM		0x60
178 #define		BPF_LEN		0x80
179 #define		BPF_MSH		0xa0
180 
181 /* alu/jmp fields */
182 #define BPF_OP(code)	((code) & 0xf0)
183 #define		BPF_ADD		0x00
184 #define		BPF_SUB		0x10
185 #define		BPF_MUL		0x20
186 #define		BPF_DIV		0x30
187 #define		BPF_OR		0x40
188 #define		BPF_AND		0x50
189 #define		BPF_LSH		0x60
190 #define		BPF_RSH		0x70
191 #define		BPF_NEG		0x80
192 #define		BPF_MOD		0x90
193 #define		BPF_XOR		0xa0
194 #define		BPF_JA		0x00
195 #define		BPF_JEQ		0x10
196 #define		BPF_JGT		0x20
197 #define		BPF_JGE		0x30
198 #define		BPF_JSET	0x40
199 #define BPF_SRC(code)	((code) & 0x08)
200 #define		BPF_K		0x00
201 #define		BPF_X		0x08
202 
203 /* ret - BPF_K and BPF_X also apply */
204 #define BPF_RVAL(code)	((code) & 0x18)
205 #define		BPF_A		0x10
206 
207 /* misc */
208 #define BPF_MISCOP(code) ((code) & 0xf8)
209 #define		BPF_TAX		0x00
210 #define		BPF_TXA		0x80
211 
212 /*
213  * The instruction data structure.
214  */
215 struct bpf_insn {
216 	u_short		code;
217 	u_char		jt;
218 	u_char		jf;
219 	bpf_u_int32	k;
220 };
221 
222 /*
223  * Macros for insn array initializers.
224  */
225 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
226 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
227 
228 /*
229  * Structure to retrieve available DLTs for the interface.
230  */
231 struct bpf_dltlist {
232 	u_int	bfl_len;	/* number of bfd_list array */
233 	u_int	*bfl_list;	/* array of DLTs */
234 };
235 
236 #ifdef _KERNEL
237 
238 struct bpf_if;
239 struct ifnet;
240 struct mbuf;
241 
242 int	 bpf_validate(const struct bpf_insn *, int);
243 void	 bpf_tap(struct bpf_if *, u_char *, u_int);
244 void	 bpf_mtap(struct bpf_if *, struct mbuf *);
245 void	 bpf_mtap_family(struct bpf_if *, struct mbuf *m, __uint8_t family);
246 void	 bpf_mtap_hdr(struct bpf_if *, caddr_t, u_int, struct mbuf *, u_int);
247 void	 bpf_ptap(struct bpf_if *, struct mbuf *, const void *, u_int);
248 void	 bpfattach(struct ifnet *, u_int, u_int);
249 void	 bpfattach_dlt(struct ifnet *, u_int, u_int, struct bpf_if **);
250 void	 bpfdetach(struct ifnet *);
251 void	 bpf_gettoken(void);
252 void	 bpf_reltoken(void);
253 
254 u_int	 bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
255 
256 #define	BPF_TAP(_ifp,_pkt,_pktlen) do {					\
257 	if ((_ifp)->if_bpf) {						\
258 		bpf_gettoken();						\
259 		if ((_ifp)->if_bpf)					\
260 			bpf_tap((_ifp)->if_bpf, (_pkt), (_pktlen));	\
261 		bpf_reltoken();						\
262 	}								\
263 } while (0)
264 
265 #define	BPF_MTAP(_ifp,_m) do {						\
266 	if ((_ifp)->if_bpf) {						\
267 		bpf_gettoken();						\
268 		if ((_ifp)->if_bpf)					\
269 			bpf_mtap((_ifp)->if_bpf, (_m));                 \
270 		bpf_reltoken();						\
271 	}								\
272 } while (0)
273 
274 /*
275  * BPF attach/detach events
276  */
277 
278 #include <sys/eventhandler.h>
279 
280 typedef void (*bpf_track_fn)(void *, struct ifnet *, int /* dlt */,
281     int /* 1 =>'s attach */);
282 EVENTHANDLER_DECLARE(bpf_track, bpf_track_fn);
283 
284 #endif	/* _KERNEL */
285 
286 /*
287  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
288  */
289 #define BPF_MEMWORDS 16
290 
291 __END_DECLS
292 
293 #endif	/* !_NET_BPF_H_ */
294