xref: /netbsd-src/sys/net/bpf.h (revision b757af438b42b93f8c6571f026d8b8ef3eaf5fc9)
1 /*	$NetBSD: bpf.h,v 1.59 2012/03/15 00:57:56 christos 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 __BEGIN_DECLS
49 
50 typedef	int bpf_int32;
51 typedef	u_int bpf_u_int32;
52 
53 /*
54  * Alignment macros.  BPF_WORDALIGN rounds up to the next
55  * even multiple of BPF_ALIGNMENT.
56  */
57 #define BPF_ALIGNMENT sizeof(long)
58 #define BPF_ALIGNMENT32 sizeof(int)
59 
60 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
61 #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1))
62 
63 #define BPF_MAXINSNS 512
64 #define BPF_DFLTBUFSIZE (1024*1024)	/* default static upper limit */
65 #define BPF_MAXBUFSIZE (1024*1024*16)	/* hard limit on sysctl'able value */
66 #define BPF_MINBUFSIZE 32
67 
68 /*
69  *  Structure for BIOCSETF.
70  */
71 struct bpf_program {
72 	u_int bf_len;
73 	struct bpf_insn *bf_insns;
74 };
75 
76 /*
77  * Struct returned by BIOCGSTATS and net.bpf.stats sysctl.
78  */
79 struct bpf_stat {
80 	uint64_t bs_recv;	/* number of packets received */
81 	uint64_t bs_drop;	/* number of packets dropped */
82 	uint64_t bs_capt;	/* number of packets captured */
83 	uint64_t bs_padding[13];
84 };
85 
86 /*
87  * Struct returned by BIOCGSTATSOLD.
88  */
89 struct bpf_stat_old {
90 	u_int bs_recv;		/* number of packets received */
91 	u_int bs_drop;		/* number of packets dropped */
92 };
93 
94 /*
95  * Struct return by BIOCVERSION.  This represents the version number of
96  * the filter language described by the instruction encodings below.
97  * bpf understands a program iff kernel_major == filter_major &&
98  * kernel_minor >= filter_minor, that is, if the value returned by the
99  * running kernel has the same major number and a minor number equal
100  * equal to or less than the filter being downloaded.  Otherwise, the
101  * results are undefined, meaning an error may be returned or packets
102  * may be accepted haphazardly.
103  * It has nothing to do with the source code version.
104  */
105 struct bpf_version {
106 	u_short bv_major;
107 	u_short bv_minor;
108 };
109 /* Current version number of filter architecture. */
110 #define BPF_MAJOR_VERSION 1
111 #define BPF_MINOR_VERSION 1
112 
113 /*
114  * BPF ioctls
115  *
116  * The first set is for compatibility with Sun's pcc style
117  * header files.  If your using gcc, we assume that you
118  * have run fixincludes so the latter set should work.
119  */
120 #define BIOCGBLEN	 _IOR('B',102, u_int)
121 #define BIOCSBLEN	_IOWR('B',102, u_int)
122 #define BIOCSETF	 _IOW('B',103, struct bpf_program)
123 #define BIOCFLUSH	  _IO('B',104)
124 #define BIOCPROMISC	  _IO('B',105)
125 #define BIOCGDLT	 _IOR('B',106, u_int)
126 #define BIOCGETIF	 _IOR('B',107, struct ifreq)
127 #define BIOCSETIF	 _IOW('B',108, struct ifreq)
128 #ifdef COMPAT_50
129 #include <compat/sys/time.h>
130 #define BIOCSORTIMEOUT	 _IOW('B',109, struct timeval50)
131 #define BIOCGORTIMEOUT	 _IOR('B',110, struct timeval50)
132 #endif
133 #define BIOCGSTATS	 _IOR('B',111, struct bpf_stat)
134 #define BIOCGSTATSOLD	 _IOR('B',111, struct bpf_stat_old)
135 #define BIOCIMMEDIATE	 _IOW('B',112, u_int)
136 #define BIOCVERSION	 _IOR('B',113, struct bpf_version)
137 #define BIOCSTCPF	 _IOW('B',114, struct bpf_program)
138 #define BIOCSUDPF	 _IOW('B',115, struct bpf_program)
139 #define BIOCGHDRCMPLT	 _IOR('B',116, u_int)
140 #define BIOCSHDRCMPLT	 _IOW('B',117, u_int)
141 #define BIOCSDLT	 _IOW('B',118, u_int)
142 #define BIOCGDLTLIST	_IOWR('B',119, struct bpf_dltlist)
143 #define BIOCGSEESENT	 _IOR('B',120, u_int)
144 #define BIOCSSEESENT	 _IOW('B',121, u_int)
145 #define BIOCSRTIMEOUT	 _IOW('B',122, struct timeval)
146 #define BIOCGRTIMEOUT	 _IOR('B',123, struct timeval)
147 #define BIOCGFEEDBACK	 _IOR('B',124, u_int)
148 #define BIOCSFEEDBACK	 _IOW('B',125, u_int)
149 #define BIOCFEEDBACK     BIOCSFEEDBACK		/* FreeBSD name */
150 
151 /*
152  * Structure prepended to each packet. This is "wire" format, so we
153  * cannot change it unfortunately to 64 bit times on 32 bit systems [yet].
154  */
155 struct bpf_timeval {
156 	long tv_sec;
157 	long tv_usec;
158 };
159 
160 struct bpf_timeval32 {
161 	int32_t tv_sec;
162 	int32_t tv_usec;
163 };
164 
165 struct bpf_hdr {
166 	struct bpf_timeval bh_tstamp;	/* time stamp */
167 	uint32_t	bh_caplen;	/* length of captured portion */
168 	uint32_t	bh_datalen;	/* original length of packet */
169 	uint16_t	bh_hdrlen;	/* length of bpf header (this struct
170 					   plus alignment padding) */
171 };
172 
173 struct bpf_hdr32 {
174 	struct bpf_timeval32 bh_tstamp;	/* time stamp */
175 	uint32_t	bh_caplen;	/* length of captured portion */
176 	uint32_t	bh_datalen;	/* original length of packet */
177 	uint16_t	bh_hdrlen;	/* length of bpf header (this struct
178 					   plus alignment padding) */
179 };
180 /*
181  * Because the structure above is not a multiple of 4 bytes, some compilers
182  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
183  * Only the kernel needs to know about it; applications use bh_hdrlen.
184  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
185  * XXX padding by using the size of the header data elements.  This is
186  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
187  */
188 #ifdef _KERNEL
189 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
190     defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
191     defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
192 #define SIZEOF_BPF_HDR 18
193 #define SIZEOF_BPF_HDR32 18
194 #else
195 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
196 #define SIZEOF_BPF_HDR32 sizeof(struct bpf_hdr32)
197 #endif
198 #endif
199 
200 /* Pull in data-link level type codes. */
201 #include <net/dlt.h>
202 
203 /*
204  * The instruction encodings.
205  */
206 /* instruction classes */
207 #define BPF_CLASS(code) ((code) & 0x07)
208 #define		BPF_LD		0x00
209 #define		BPF_LDX		0x01
210 #define		BPF_ST		0x02
211 #define		BPF_STX		0x03
212 #define		BPF_ALU		0x04
213 #define		BPF_JMP		0x05
214 #define		BPF_RET		0x06
215 #define		BPF_MISC	0x07
216 
217 /* ld/ldx fields */
218 #define BPF_SIZE(code)	((code) & 0x18)
219 #define		BPF_W		0x00
220 #define		BPF_H		0x08
221 #define		BPF_B		0x10
222 #define BPF_MODE(code)	((code) & 0xe0)
223 #define		BPF_IMM 	0x00
224 #define		BPF_ABS		0x20
225 #define		BPF_IND		0x40
226 #define		BPF_MEM		0x60
227 #define		BPF_LEN		0x80
228 #define		BPF_MSH		0xa0
229 
230 /* alu/jmp fields */
231 #define BPF_OP(code)	((code) & 0xf0)
232 #define		BPF_ADD		0x00
233 #define		BPF_SUB		0x10
234 #define		BPF_MUL		0x20
235 #define		BPF_DIV		0x30
236 #define		BPF_OR		0x40
237 #define		BPF_AND		0x50
238 #define		BPF_LSH		0x60
239 #define		BPF_RSH		0x70
240 #define		BPF_NEG		0x80
241 #define		BPF_JA		0x00
242 #define		BPF_JEQ		0x10
243 #define		BPF_JGT		0x20
244 #define		BPF_JGE		0x30
245 #define		BPF_JSET	0x40
246 #define BPF_SRC(code)	((code) & 0x08)
247 #define		BPF_K		0x00
248 #define		BPF_X		0x08
249 
250 /* ret - BPF_K and BPF_X also apply */
251 #define BPF_RVAL(code)	((code) & 0x18)
252 #define		BPF_A		0x10
253 
254 /* misc */
255 #define BPF_MISCOP(code) ((code) & 0xf8)
256 #define		BPF_TAX		0x00
257 #define		BPF_TXA		0x80
258 
259 /*
260  * The instruction data structure.
261  */
262 struct bpf_insn {
263 	uint16_t  code;
264 	u_char 	  jt;
265 	u_char 	  jf;
266 	uint32_t  k;
267 };
268 
269 /*
270  * Macros for insn array initializers.
271  */
272 #define BPF_STMT(code, k) { (uint16_t)(code), 0, 0, k }
273 #define BPF_JUMP(code, k, jt, jf) { (uint16_t)(code), jt, jf, k }
274 
275 /*
276  * Structure to retrieve available DLTs for the interface.
277  */
278 struct bpf_dltlist {
279 	u_int	bfl_len;	/* number of bfd_list array */
280 	u_int	*bfl_list;	/* array of DLTs */
281 };
282 
283 #ifdef _KERNEL
284 #include <net/if.h>
285 struct bpf_if;
286 
287 struct bpf_ops {
288 	void (*bpf_attach)(struct ifnet *, u_int, u_int, struct bpf_if **);
289 	void (*bpf_detach)(struct ifnet *);
290 	void (*bpf_change_type)(struct ifnet *, u_int, u_int);
291 
292 	void (*bpf_tap)(struct bpf_if *, u_char *, u_int);
293 	void (*bpf_mtap)(struct bpf_if *, struct mbuf *);
294 	void (*bpf_mtap2)(struct bpf_if *, void *, u_int, struct mbuf *);
295 	void (*bpf_mtap_af)(struct bpf_if *, uint32_t, struct mbuf *);
296 	void (*bpf_mtap_sl_in)(struct bpf_if *, u_char *, struct mbuf **);
297 	void (*bpf_mtap_sl_out)(struct bpf_if *, u_char *, struct mbuf *);
298 };
299 
300 extern struct bpf_ops *bpf_ops;
301 
302 static inline void
303 bpf_attach(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
304 {
305 	bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, &_ifp->if_bpf);
306 }
307 
308 static inline void
309 bpf_attach2(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen, struct bpf_if **_dp)
310 {
311 	bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, _dp);
312 }
313 
314 static inline void
315 bpf_tap(struct ifnet *_ifp, u_char *_pkt, u_int _len)
316 {
317 	if (_ifp->if_bpf)
318 		bpf_ops->bpf_tap(_ifp->if_bpf, _pkt, _len);
319 }
320 
321 static inline void
322 bpf_mtap(struct ifnet *_ifp, struct mbuf *_m)
323 {
324 	if (_ifp->if_bpf)
325 		bpf_ops->bpf_mtap(_ifp->if_bpf, _m);
326 }
327 
328 static inline void
329 bpf_mtap2(struct bpf_if *_bpf, void *_data, u_int _dlen, struct mbuf *_m)
330 {
331 	bpf_ops->bpf_mtap2(_bpf, _data, _dlen, _m);
332 }
333 
334 static inline void
335 bpf_mtap3(struct bpf_if *_bpf, struct mbuf *_m)
336 {
337 	if (_bpf)
338 		bpf_ops->bpf_mtap(_bpf, _m);
339 }
340 
341 static inline void
342 bpf_mtap_af(struct ifnet *_ifp, uint32_t _af, struct mbuf *_m)
343 {
344 	if (_ifp->if_bpf)
345 		bpf_ops->bpf_mtap_af(_ifp->if_bpf, _af, _m);
346 }
347 
348 static inline void
349 bpf_change_type(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
350 {
351 	bpf_ops->bpf_change_type(_ifp, _dlt, _hdrlen);
352 }
353 
354 static inline void
355 bpf_detach(struct ifnet *_ifp)
356 {
357 	bpf_ops->bpf_detach(_ifp);
358 }
359 
360 static inline void
361 bpf_mtap_sl_in(struct ifnet *_ifp, u_char *_hdr, struct mbuf **_m)
362 {
363 	bpf_ops->bpf_mtap_sl_in(_ifp->if_bpf, _hdr, _m);
364 }
365 
366 static inline void
367 bpf_mtap_sl_out(struct ifnet *_ifp, u_char *_hdr, struct mbuf *_m)
368 {
369 	if (_ifp->if_bpf)
370 		bpf_ops->bpf_mtap_sl_out(_ifp->if_bpf, _hdr, _m);
371 }
372 
373 
374 void     bpf_setops(void);
375 
376 void     bpf_ops_handover_enter(struct bpf_ops *);
377 void     bpf_ops_handover_exit(void);
378 
379 void	 bpfilterattach(int);
380 
381 #endif
382 
383 int	 bpf_validate(const struct bpf_insn *, int);
384 u_int	 bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int);
385 
386 __END_DECLS
387 
388 /*
389  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
390  */
391 #define BPF_MEMWORDS 16
392 
393 #endif /* !_NET_BPF_H_ */
394