xref: /netbsd-src/sys/net/bpf.h (revision a5847cc334d9a7029f6352b847e9e8d71a0f9e0c)
1 /*	$NetBSD: bpf.h,v 1.58 2011/08/30 14:22:22 bouyer 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_ALIGNMENT32 sizeof(int)
57 
58 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
59 #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1))
60 
61 #define BPF_MAXINSNS 512
62 #define BPF_DFLTBUFSIZE (1024*1024)	/* default static upper limit */
63 #define BPF_MAXBUFSIZE (1024*1024*16)	/* hard limit on sysctl'able value */
64 #define BPF_MINBUFSIZE 32
65 
66 /*
67  *  Structure for BIOCSETF.
68  */
69 struct bpf_program {
70 	u_int bf_len;
71 	struct bpf_insn *bf_insns;
72 };
73 
74 /*
75  * Struct returned by BIOCGSTATS and net.bpf.stats sysctl.
76  */
77 struct bpf_stat {
78 	uint64_t bs_recv;	/* number of packets received */
79 	uint64_t bs_drop;	/* number of packets dropped */
80 	uint64_t bs_capt;	/* number of packets captured */
81 	uint64_t bs_padding[13];
82 };
83 
84 /*
85  * Struct returned by BIOCGSTATSOLD.
86  */
87 struct bpf_stat_old {
88 	u_int bs_recv;		/* number of packets received */
89 	u_int bs_drop;		/* number of packets dropped */
90 };
91 
92 /*
93  * Struct return by BIOCVERSION.  This represents the version number of
94  * the filter language described by the instruction encodings below.
95  * bpf understands a program iff kernel_major == filter_major &&
96  * kernel_minor >= filter_minor, that is, if the value returned by the
97  * running kernel has the same major number and a minor number equal
98  * equal to or less than the filter being downloaded.  Otherwise, the
99  * results are undefined, meaning an error may be returned or packets
100  * may be accepted haphazardly.
101  * It has nothing to do with the source code version.
102  */
103 struct bpf_version {
104 	u_short bv_major;
105 	u_short bv_minor;
106 };
107 /* Current version number of filter architecture. */
108 #define BPF_MAJOR_VERSION 1
109 #define BPF_MINOR_VERSION 1
110 
111 /*
112  * BPF ioctls
113  *
114  * The first set is for compatibility with Sun's pcc style
115  * header files.  If your using gcc, we assume that you
116  * have run fixincludes so the latter set should work.
117  */
118 #define BIOCGBLEN	 _IOR('B',102, u_int)
119 #define BIOCSBLEN	_IOWR('B',102, u_int)
120 #define BIOCSETF	 _IOW('B',103, struct bpf_program)
121 #define BIOCFLUSH	  _IO('B',104)
122 #define BIOCPROMISC	  _IO('B',105)
123 #define BIOCGDLT	 _IOR('B',106, u_int)
124 #define BIOCGETIF	 _IOR('B',107, struct ifreq)
125 #define BIOCSETIF	 _IOW('B',108, struct ifreq)
126 #ifdef COMPAT_50
127 #include <compat/sys/time.h>
128 #define BIOCSORTIMEOUT	 _IOW('B',109, struct timeval50)
129 #define BIOCGORTIMEOUT	 _IOR('B',110, struct timeval50)
130 #endif
131 #define BIOCGSTATS	 _IOR('B',111, struct bpf_stat)
132 #define BIOCGSTATSOLD	 _IOR('B',111, struct bpf_stat_old)
133 #define BIOCIMMEDIATE	 _IOW('B',112, u_int)
134 #define BIOCVERSION	 _IOR('B',113, struct bpf_version)
135 #define BIOCSTCPF	 _IOW('B',114, struct bpf_program)
136 #define BIOCSUDPF	 _IOW('B',115, struct bpf_program)
137 #define BIOCGHDRCMPLT	 _IOR('B',116, u_int)
138 #define BIOCSHDRCMPLT	 _IOW('B',117, u_int)
139 #define BIOCSDLT	 _IOW('B',118, u_int)
140 #define BIOCGDLTLIST	_IOWR('B',119, struct bpf_dltlist)
141 #define BIOCGSEESENT	 _IOR('B',120, u_int)
142 #define BIOCSSEESENT	 _IOW('B',121, u_int)
143 #define BIOCSRTIMEOUT	 _IOW('B',122, struct timeval)
144 #define BIOCGRTIMEOUT	 _IOR('B',123, struct timeval)
145 #define BIOCGFEEDBACK	 _IOR('B',124, u_int)
146 #define BIOCSFEEDBACK	 _IOW('B',125, u_int)
147 #define BIOCFEEDBACK     BIOCSFEEDBACK		/* FreeBSD name */
148 
149 /*
150  * Structure prepended to each packet. This is "wire" format, so we
151  * cannot change it unfortunately to 64 bit times on 32 bit systems [yet].
152  */
153 struct bpf_timeval {
154 	long tv_sec;
155 	long tv_usec;
156 };
157 
158 struct bpf_timeval32 {
159 	int32_t tv_sec;
160 	int32_t tv_usec;
161 };
162 
163 struct bpf_hdr {
164 	struct bpf_timeval bh_tstamp;	/* time stamp */
165 	uint32_t	bh_caplen;	/* length of captured portion */
166 	uint32_t	bh_datalen;	/* original length of packet */
167 	uint16_t	bh_hdrlen;	/* length of bpf header (this struct
168 					   plus alignment padding) */
169 };
170 
171 struct bpf_hdr32 {
172 	struct bpf_timeval32 bh_tstamp;	/* time stamp */
173 	uint32_t	bh_caplen;	/* length of captured portion */
174 	uint32_t	bh_datalen;	/* original length of packet */
175 	uint16_t	bh_hdrlen;	/* length of bpf header (this struct
176 					   plus alignment padding) */
177 };
178 /*
179  * Because the structure above is not a multiple of 4 bytes, some compilers
180  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
181  * Only the kernel needs to know about it; applications use bh_hdrlen.
182  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
183  * XXX padding by using the size of the header data elements.  This is
184  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
185  */
186 #ifdef _KERNEL
187 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
188     defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
189     defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
190 #define SIZEOF_BPF_HDR 18
191 #define SIZEOF_BPF_HDR32 18
192 #else
193 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
194 #define SIZEOF_BPF_HDR32 sizeof(struct bpf_hdr32)
195 #endif
196 #endif
197 
198 /* Pull in data-link level type codes. */
199 #include <net/dlt.h>
200 
201 /*
202  * The instruction encodings.
203  */
204 /* instruction classes */
205 #define BPF_CLASS(code) ((code) & 0x07)
206 #define		BPF_LD		0x00
207 #define		BPF_LDX		0x01
208 #define		BPF_ST		0x02
209 #define		BPF_STX		0x03
210 #define		BPF_ALU		0x04
211 #define		BPF_JMP		0x05
212 #define		BPF_RET		0x06
213 #define		BPF_MISC	0x07
214 
215 /* ld/ldx fields */
216 #define BPF_SIZE(code)	((code) & 0x18)
217 #define		BPF_W		0x00
218 #define		BPF_H		0x08
219 #define		BPF_B		0x10
220 #define BPF_MODE(code)	((code) & 0xe0)
221 #define		BPF_IMM 	0x00
222 #define		BPF_ABS		0x20
223 #define		BPF_IND		0x40
224 #define		BPF_MEM		0x60
225 #define		BPF_LEN		0x80
226 #define		BPF_MSH		0xa0
227 
228 /* alu/jmp fields */
229 #define BPF_OP(code)	((code) & 0xf0)
230 #define		BPF_ADD		0x00
231 #define		BPF_SUB		0x10
232 #define		BPF_MUL		0x20
233 #define		BPF_DIV		0x30
234 #define		BPF_OR		0x40
235 #define		BPF_AND		0x50
236 #define		BPF_LSH		0x60
237 #define		BPF_RSH		0x70
238 #define		BPF_NEG		0x80
239 #define		BPF_JA		0x00
240 #define		BPF_JEQ		0x10
241 #define		BPF_JGT		0x20
242 #define		BPF_JGE		0x30
243 #define		BPF_JSET	0x40
244 #define BPF_SRC(code)	((code) & 0x08)
245 #define		BPF_K		0x00
246 #define		BPF_X		0x08
247 
248 /* ret - BPF_K and BPF_X also apply */
249 #define BPF_RVAL(code)	((code) & 0x18)
250 #define		BPF_A		0x10
251 
252 /* misc */
253 #define BPF_MISCOP(code) ((code) & 0xf8)
254 #define		BPF_TAX		0x00
255 #define		BPF_TXA		0x80
256 
257 /*
258  * The instruction data structure.
259  */
260 struct bpf_insn {
261 	uint16_t  code;
262 	u_char 	  jt;
263 	u_char 	  jf;
264 	uint32_t  k;
265 };
266 
267 /*
268  * Macros for insn array initializers.
269  */
270 #define BPF_STMT(code, k) { (uint16_t)(code), 0, 0, k }
271 #define BPF_JUMP(code, k, jt, jf) { (uint16_t)(code), jt, jf, k }
272 
273 /*
274  * Structure to retrieve available DLTs for the interface.
275  */
276 struct bpf_dltlist {
277 	u_int	bfl_len;	/* number of bfd_list array */
278 	u_int	*bfl_list;	/* array of DLTs */
279 };
280 
281 #ifdef _KERNEL
282 #include <net/if.h>
283 struct bpf_if;
284 
285 struct bpf_ops {
286 	void (*bpf_attach)(struct ifnet *, u_int, u_int, struct bpf_if **);
287 	void (*bpf_detach)(struct ifnet *);
288 	void (*bpf_change_type)(struct ifnet *, u_int, u_int);
289 
290 	void (*bpf_tap)(struct bpf_if *, u_char *, u_int);
291 	void (*bpf_mtap)(struct bpf_if *, struct mbuf *);
292 	void (*bpf_mtap2)(struct bpf_if *, void *, u_int, struct mbuf *);
293 	void (*bpf_mtap_af)(struct bpf_if *, uint32_t, struct mbuf *);
294 	void (*bpf_mtap_sl_in)(struct bpf_if *, u_char *, struct mbuf **);
295 	void (*bpf_mtap_sl_out)(struct bpf_if *, u_char *, struct mbuf *);
296 };
297 
298 extern struct bpf_ops *bpf_ops;
299 
300 static inline void
301 bpf_attach(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
302 {
303 	bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, &_ifp->if_bpf);
304 }
305 
306 static inline void
307 bpf_attach2(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen, struct bpf_if **_dp)
308 {
309 	bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, _dp);
310 }
311 
312 static inline void
313 bpf_tap(struct ifnet *_ifp, u_char *_pkt, u_int _len)
314 {
315 	if (_ifp->if_bpf)
316 		bpf_ops->bpf_tap(_ifp->if_bpf, _pkt, _len);
317 }
318 
319 static inline void
320 bpf_mtap(struct ifnet *_ifp, struct mbuf *_m)
321 {
322 	if (_ifp->if_bpf)
323 		bpf_ops->bpf_mtap(_ifp->if_bpf, _m);
324 }
325 
326 static inline void
327 bpf_mtap2(struct bpf_if *_bpf, void *_data, u_int _dlen, struct mbuf *_m)
328 {
329 	bpf_ops->bpf_mtap2(_bpf, _data, _dlen, _m);
330 }
331 
332 static inline void
333 bpf_mtap3(struct bpf_if *_bpf, struct mbuf *_m)
334 {
335 	if (_bpf)
336 		bpf_ops->bpf_mtap(_bpf, _m);
337 }
338 
339 static inline void
340 bpf_mtap_af(struct ifnet *_ifp, uint32_t _af, struct mbuf *_m)
341 {
342 	if (_ifp->if_bpf)
343 		bpf_ops->bpf_mtap_af(_ifp->if_bpf, _af, _m);
344 }
345 
346 static inline void
347 bpf_change_type(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
348 {
349 	bpf_ops->bpf_change_type(_ifp, _dlt, _hdrlen);
350 }
351 
352 static inline void
353 bpf_detach(struct ifnet *_ifp)
354 {
355 	bpf_ops->bpf_detach(_ifp);
356 }
357 
358 static inline void
359 bpf_mtap_sl_in(struct ifnet *_ifp, u_char *_hdr, struct mbuf **_m)
360 {
361 	bpf_ops->bpf_mtap_sl_in(_ifp->if_bpf, _hdr, _m);
362 }
363 
364 static inline void
365 bpf_mtap_sl_out(struct ifnet *_ifp, u_char *_hdr, struct mbuf *_m)
366 {
367 	if (_ifp->if_bpf)
368 		bpf_ops->bpf_mtap_sl_out(_ifp->if_bpf, _hdr, _m);
369 }
370 
371 
372 void     bpf_setops(void);
373 
374 void     bpf_ops_handover_enter(struct bpf_ops *);
375 void     bpf_ops_handover_exit(void);
376 
377 void	 bpfilterattach(int);
378 
379 #endif
380 
381 int	 bpf_validate(const struct bpf_insn *, int);
382 u_int	 bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int);
383 
384 /*
385  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
386  */
387 #define BPF_MEMWORDS 16
388 
389 #endif /* !_NET_BPF_H_ */
390