xref: /netbsd/sys/net/bpf.h (revision 58e86755)
1 /*	$NetBSD: bpf.h,v 1.55 2010/04/05 07:22:22 joerg 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. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)bpf.h	8.2 (Berkeley) 1/9/95
37  * @(#) Header: bpf.h,v 1.36 97/06/12 14:29:53 leres Exp  (LBL)
38  */
39 
40 #ifndef _NET_BPF_H_
41 #define _NET_BPF_H_
42 
43 #include <sys/time.h>
44 
45 /* BSD style release date */
46 #define BPF_RELEASE 199606
47 
48 typedef	int bpf_int32;
49 typedef	u_int bpf_u_int32;
50 
51 /*
52  * Alignment macros.  BPF_WORDALIGN rounds up to the next
53  * even multiple of BPF_ALIGNMENT.
54  */
55 #define BPF_ALIGNMENT sizeof(long)
56 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
57 
58 #define BPF_MAXINSNS 512
59 #define BPF_DFLTBUFSIZE (1024*1024)	/* default static upper limit */
60 #define BPF_MAXBUFSIZE (1024*1024*16)	/* hard limit on sysctl'able value */
61 #define BPF_MINBUFSIZE 32
62 
63 /*
64  *  Structure for BIOCSETF.
65  */
66 struct bpf_program {
67 	u_int bf_len;
68 	struct bpf_insn *bf_insns;
69 };
70 
71 /*
72  * Struct returned by BIOCGSTATS and net.bpf.stats sysctl.
73  */
74 struct bpf_stat {
75 	uint64_t bs_recv;	/* number of packets received */
76 	uint64_t bs_drop;	/* number of packets dropped */
77 	uint64_t bs_capt;	/* number of packets captured */
78 	uint64_t bs_padding[13];
79 };
80 
81 /*
82  * Struct returned by BIOCGSTATSOLD.
83  */
84 struct bpf_stat_old {
85 	u_int bs_recv;		/* number of packets received */
86 	u_int bs_drop;		/* number of packets dropped */
87 };
88 
89 /*
90  * Struct return by BIOCVERSION.  This represents the version number of
91  * the filter language described by the instruction encodings below.
92  * bpf understands a program iff kernel_major == filter_major &&
93  * kernel_minor >= filter_minor, that is, if the value returned by the
94  * running kernel has the same major number and a minor number equal
95  * equal to or less than the filter being downloaded.  Otherwise, the
96  * results are undefined, meaning an error may be returned or packets
97  * may be accepted haphazardly.
98  * It has nothing to do with the source code version.
99  */
100 struct bpf_version {
101 	u_short bv_major;
102 	u_short bv_minor;
103 };
104 /* Current version number of filter architecture. */
105 #define BPF_MAJOR_VERSION 1
106 #define BPF_MINOR_VERSION 1
107 
108 /*
109  * BPF ioctls
110  *
111  * The first set is for compatibility with Sun's pcc style
112  * header files.  If your using gcc, we assume that you
113  * have run fixincludes so the latter set should work.
114  */
115 #define BIOCGBLEN	 _IOR('B',102, u_int)
116 #define BIOCSBLEN	_IOWR('B',102, u_int)
117 #define BIOCSETF	 _IOW('B',103, struct bpf_program)
118 #define BIOCFLUSH	  _IO('B',104)
119 #define BIOCPROMISC	  _IO('B',105)
120 #define BIOCGDLT	 _IOR('B',106, u_int)
121 #define BIOCGETIF	 _IOR('B',107, struct ifreq)
122 #define BIOCSETIF	 _IOW('B',108, struct ifreq)
123 #ifdef COMPAT_50
124 #include <compat/sys/time.h>
125 #define BIOCSORTIMEOUT	 _IOW('B',109, struct timeval50)
126 #define BIOCGORTIMEOUT	 _IOR('B',110, struct timeval50)
127 #endif
128 #define BIOCGSTATS	 _IOR('B',111, struct bpf_stat)
129 #define BIOCGSTATSOLD	 _IOR('B',111, struct bpf_stat_old)
130 #define BIOCIMMEDIATE	 _IOW('B',112, u_int)
131 #define BIOCVERSION	 _IOR('B',113, struct bpf_version)
132 #define BIOCSTCPF	 _IOW('B',114, struct bpf_program)
133 #define BIOCSUDPF	 _IOW('B',115, struct bpf_program)
134 #define BIOCGHDRCMPLT	 _IOR('B',116, u_int)
135 #define BIOCSHDRCMPLT	 _IOW('B',117, u_int)
136 #define BIOCSDLT	 _IOW('B',118, u_int)
137 #define BIOCGDLTLIST	_IOWR('B',119, struct bpf_dltlist)
138 #define BIOCGSEESENT	 _IOR('B',120, u_int)
139 #define BIOCSSEESENT	 _IOW('B',121, u_int)
140 #define BIOCSRTIMEOUT	 _IOW('B',122, struct timeval)
141 #define BIOCGRTIMEOUT	 _IOR('B',123, struct timeval)
142 #define BIOCGFEEDBACK	 _IOR('B',124, u_int)
143 #define BIOCSFEEDBACK	 _IOW('B',125, u_int)
144 #define BIOCFEEDBACK     BIOCSFEEDBACK		/* FreeBSD name */
145 
146 /*
147  * Structure prepended to each packet. This is "wire" format, so we
148  * cannot change it unfortunately to 64 bit times on 32 bit systems [yet].
149  */
150 struct bpf_timeval {
151 	long tv_sec;
152 	long tv_usec;
153 };
154 
155 struct bpf_hdr {
156 	struct bpf_timeval bh_tstamp;	/* time stamp */
157 	uint32_t	bh_caplen;	/* length of captured portion */
158 	uint32_t	bh_datalen;	/* original length of packet */
159 	uint16_t	bh_hdrlen;	/* length of bpf header (this struct
160 					   plus alignment padding) */
161 };
162 /*
163  * Because the structure above is not a multiple of 4 bytes, some compilers
164  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
165  * Only the kernel needs to know about it; applications use bh_hdrlen.
166  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
167  * XXX padding by using the size of the header data elements.  This is
168  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
169  */
170 #ifdef _KERNEL
171 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
172     defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
173     defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
174 #define SIZEOF_BPF_HDR 18
175 #else
176 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
177 #endif
178 #endif
179 
180 /* Pull in data-link level type codes. */
181 #include <net/dlt.h>
182 
183 /*
184  * The instruction encodings.
185  */
186 /* instruction classes */
187 #define BPF_CLASS(code) ((code) & 0x07)
188 #define		BPF_LD		0x00
189 #define		BPF_LDX		0x01
190 #define		BPF_ST		0x02
191 #define		BPF_STX		0x03
192 #define		BPF_ALU		0x04
193 #define		BPF_JMP		0x05
194 #define		BPF_RET		0x06
195 #define		BPF_MISC	0x07
196 
197 /* ld/ldx fields */
198 #define BPF_SIZE(code)	((code) & 0x18)
199 #define		BPF_W		0x00
200 #define		BPF_H		0x08
201 #define		BPF_B		0x10
202 #define BPF_MODE(code)	((code) & 0xe0)
203 #define		BPF_IMM 	0x00
204 #define		BPF_ABS		0x20
205 #define		BPF_IND		0x40
206 #define		BPF_MEM		0x60
207 #define		BPF_LEN		0x80
208 #define		BPF_MSH		0xa0
209 
210 /* alu/jmp fields */
211 #define BPF_OP(code)	((code) & 0xf0)
212 #define		BPF_ADD		0x00
213 #define		BPF_SUB		0x10
214 #define		BPF_MUL		0x20
215 #define		BPF_DIV		0x30
216 #define		BPF_OR		0x40
217 #define		BPF_AND		0x50
218 #define		BPF_LSH		0x60
219 #define		BPF_RSH		0x70
220 #define		BPF_NEG		0x80
221 #define		BPF_JA		0x00
222 #define		BPF_JEQ		0x10
223 #define		BPF_JGT		0x20
224 #define		BPF_JGE		0x30
225 #define		BPF_JSET	0x40
226 #define BPF_SRC(code)	((code) & 0x08)
227 #define		BPF_K		0x00
228 #define		BPF_X		0x08
229 
230 /* ret - BPF_K and BPF_X also apply */
231 #define BPF_RVAL(code)	((code) & 0x18)
232 #define		BPF_A		0x10
233 
234 /* misc */
235 #define BPF_MISCOP(code) ((code) & 0xf8)
236 #define		BPF_TAX		0x00
237 #define		BPF_TXA		0x80
238 
239 /*
240  * The instruction data structure.
241  */
242 struct bpf_insn {
243 	uint16_t  code;
244 	u_char 	  jt;
245 	u_char 	  jf;
246 	uint32_t  k;
247 };
248 
249 /*
250  * Macros for insn array initializers.
251  */
252 #define BPF_STMT(code, k) { (uint16_t)(code), 0, 0, k }
253 #define BPF_JUMP(code, k, jt, jf) { (uint16_t)(code), jt, jf, k }
254 
255 /*
256  * Structure to retrieve available DLTs for the interface.
257  */
258 struct bpf_dltlist {
259 	u_int	bfl_len;	/* number of bfd_list array */
260 	u_int	*bfl_list;	/* array of DLTs */
261 };
262 
263 #ifdef _KERNEL
264 #include <net/if.h>
265 struct bpf_if;
266 
267 struct bpf_ops {
268 	void (*bpf_attach)(struct ifnet *, u_int, u_int, struct bpf_if **);
269 	void (*bpf_detach)(struct ifnet *);
270 	void (*bpf_change_type)(struct ifnet *, u_int, u_int);
271 
272 	void (*bpf_tap)(struct bpf_if *, u_char *, u_int);
273 	void (*bpf_mtap)(struct bpf_if *, struct mbuf *);
274 	void (*bpf_mtap2)(struct bpf_if *, void *, u_int, struct mbuf *);
275 	void (*bpf_mtap_af)(struct bpf_if *, uint32_t, struct mbuf *);
276 	void (*bpf_mtap_sl_in)(struct bpf_if *, u_char *, struct mbuf **);
277 	void (*bpf_mtap_sl_out)(struct bpf_if *, u_char *, struct mbuf *);
278 };
279 
280 extern struct bpf_ops *bpf_ops;
281 
282 static inline void
283 bpf_attach(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
284 {
285 	bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, &_ifp->if_bpf);
286 }
287 
288 static inline void
289 bpf_attach2(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen, struct bpf_if **_dp)
290 {
291 	bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, _dp);
292 }
293 
294 static inline void
295 bpf_tap(struct ifnet *_ifp, u_char *_pkt, u_int _len)
296 {
297 	if (_ifp->if_bpf)
298 		bpf_ops->bpf_tap(_ifp->if_bpf, _pkt, _len);
299 }
300 
301 static inline void
302 bpf_mtap(struct ifnet *_ifp, struct mbuf *_m)
303 {
304 	if (_ifp->if_bpf)
305 		bpf_ops->bpf_mtap(_ifp->if_bpf, _m);
306 }
307 
308 static inline void
309 bpf_mtap2(struct bpf_if *_bpf, void *_data, u_int _dlen, struct mbuf *_m)
310 {
311 	bpf_ops->bpf_mtap2(_bpf, _data, _dlen, _m);
312 }
313 
314 static inline void
315 bpf_mtap3(struct bpf_if *_bpf, struct mbuf *_m)
316 {
317 	if (_bpf)
318 		bpf_ops->bpf_mtap(_bpf, _m);
319 }
320 
321 static inline void
322 bpf_mtap_af(struct ifnet *_ifp, uint32_t _af, struct mbuf *_m)
323 {
324 	if (_ifp->if_bpf)
325 		bpf_ops->bpf_mtap_af(_ifp->if_bpf, _af, _m);
326 }
327 
328 static inline void
329 bpf_change_type(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
330 {
331 	bpf_ops->bpf_change_type(_ifp, _dlt, _hdrlen);
332 }
333 
334 static inline void
335 bpf_detach(struct ifnet *_ifp)
336 {
337 	bpf_ops->bpf_detach(_ifp);
338 }
339 
340 static inline void
341 bpf_mtap_sl_in(struct ifnet *_ifp, u_char *_hdr, struct mbuf **_m)
342 {
343 	bpf_ops->bpf_mtap_sl_in(_ifp->if_bpf, _hdr, _m);
344 }
345 
346 static inline void
347 bpf_mtap_sl_out(struct ifnet *_ifp, u_char *_hdr, struct mbuf *_m)
348 {
349 	if (_ifp->if_bpf)
350 		bpf_ops->bpf_mtap_sl_out(_ifp->if_bpf, _hdr, _m);
351 }
352 
353 
354 void     bpf_setops(void);
355 
356 void     bpf_ops_handover_enter(struct bpf_ops *);
357 void     bpf_ops_handover_exit(void);
358 
359 void	 bpfilterattach(int);
360 
361 int	 bpf_validate(struct bpf_insn *, int);
362 #endif
363 
364 u_int	 bpf_filter(struct bpf_insn *, u_char *, u_int, u_int);
365 
366 /*
367  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
368  */
369 #define BPF_MEMWORDS 16
370 
371 #endif /* !_NET_BPF_H_ */
372