1/* $NetBSD: bpf.h,v 1.67 2015/09/05 20:01:21 dholland 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/ioccom.h>
44#include <sys/time.h>
45
46/* BSD style release date */
47#define BPF_RELEASE 199606
48
49/* Date when COP instructions and external memory have been released. */
50#define BPF_COP_EXTMEM_RELEASE 20140624
51
52__BEGIN_DECLS
53
54typedef int bpf_int32;
55typedef u_int 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_ALIGNMENT32 sizeof(int)
63
64#define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
65#define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1))
66
67#define BPF_MAXINSNS 512
68#define BPF_DFLTBUFSIZE (1024*1024) /* default static upper limit */
69#define BPF_MAXBUFSIZE (1024*1024*16) /* hard limit on sysctl'able value */
70#define BPF_MINBUFSIZE 32
71
72/*
73 * Structure for BIOCSETF.
74 */
75struct bpf_program {
76 u_int bf_len;
77 struct bpf_insn *bf_insns;
78};
79
80/*
81 * Struct returned by BIOCGSTATS and net.bpf.stats sysctl.
82 */
83struct bpf_stat {
84 uint64_t bs_recv; /* number of packets received */
85 uint64_t bs_drop; /* number of packets dropped */
86 uint64_t bs_capt; /* number of packets captured */
87 uint64_t bs_padding[13];
88};
89
90/*
91 * Struct returned by BIOCGSTATSOLD.
92 */
93struct bpf_stat_old {
94 u_int bs_recv; /* number of packets received */
95 u_int bs_drop; /* number of packets dropped */
96};
97
98/*
99 * Struct return by BIOCVERSION. This represents the version number of
100 * the filter language described by the instruction encodings below.
101 * bpf understands a program iff kernel_major == filter_major &&
102 * kernel_minor >= filter_minor, that is, if the value returned by the
103 * running kernel has the same major number and a minor number equal
104 * equal to or less than the filter being downloaded. Otherwise, the
105 * results are undefined, meaning an error may be returned or packets
106 * may be accepted haphazardly.
107 * It has nothing to do with the source code version.
108 */
109struct bpf_version {
110 u_short bv_major;
111 u_short bv_minor;
112};
113/* Current version number of filter architecture. */
114#define BPF_MAJOR_VERSION 1
115#define BPF_MINOR_VERSION 1
116
117/*
118 * BPF ioctls
119 *
120 * The first set is for compatibility with Sun's pcc style
121 * header files. If your using gcc, we assume that you
122 * have run fixincludes so the latter set should work.
123 */
124#define BIOCGBLEN _IOR('B',102, u_int)
125#define BIOCSBLEN _IOWR('B',102, u_int)
126#define BIOCSETF _IOW('B',103, struct bpf_program)
127#define BIOCFLUSH _IO('B',104)
128#define BIOCPROMISC _IO('B',105)
129#define BIOCGDLT _IOR('B',106, u_int)
130#define BIOCGETIF _IOR('B',107, struct ifreq)
131#define BIOCSETIF _IOW('B',108, struct ifreq)
132#ifdef COMPAT_50
133#include <compat/sys/time.h>
134#define BIOCSORTIMEOUT _IOW('B',109, struct timeval50)
135#define BIOCGORTIMEOUT _IOR('B',110, struct timeval50)
136#endif
137#define BIOCGSTATS _IOR('B',111, struct bpf_stat)
138#define BIOCGSTATSOLD _IOR('B',111, struct bpf_stat_old)
139#define BIOCIMMEDIATE _IOW('B',112, u_int)
140#define BIOCVERSION _IOR('B',113, struct bpf_version)
141#define BIOCSTCPF _IOW('B',114, struct bpf_program)
142#define BIOCSUDPF _IOW('B',115, struct bpf_program)
143#define BIOCGHDRCMPLT _IOR('B',116, u_int)
144#define BIOCSHDRCMPLT _IOW('B',117, u_int)
145#define BIOCSDLT _IOW('B',118, u_int)
146#define BIOCGDLTLIST _IOWR('B',119, struct bpf_dltlist)
147#define BIOCGSEESENT _IOR('B',120, u_int)
148#define BIOCSSEESENT _IOW('B',121, u_int)
149#define BIOCSRTIMEOUT _IOW('B',122, struct timeval)
150#define BIOCGRTIMEOUT _IOR('B',123, struct timeval)
151#define BIOCGFEEDBACK _IOR('B',124, u_int)
152#define BIOCSFEEDBACK _IOW('B',125, u_int)
153#define BIOCFEEDBACK BIOCSFEEDBACK /* FreeBSD name */
154
155/*
156 * Structure prepended to each packet. This is "wire" format, so we
157 * cannot change it unfortunately to 64 bit times on 32 bit systems [yet].
158 */
159struct bpf_timeval {
160 long tv_sec;
161 long tv_usec;
162};
163
164struct bpf_timeval32 {
165 int32_t tv_sec;
166 int32_t tv_usec;
167};
168
169struct bpf_hdr {
170 struct bpf_timeval bh_tstamp; /* time stamp */
171 uint32_t bh_caplen; /* length of captured portion */
172 uint32_t bh_datalen; /* original length of packet */
173 uint16_t bh_hdrlen; /* length of bpf header (this struct
174 plus alignment padding) */
175};
176
177struct bpf_hdr32 {
178 struct bpf_timeval32 bh_tstamp; /* time stamp */
179 uint32_t bh_caplen; /* length of captured portion */
180 uint32_t bh_datalen; /* original length of packet */
181 uint16_t bh_hdrlen; /* length of bpf header (this struct
182 plus alignment padding) */
183};
184/*
185 * Because the structure above is not a multiple of 4 bytes, some compilers
186 * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
187 * Only the kernel needs to know about it; applications use bh_hdrlen.
188 * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
189 * XXX padding by using the size of the header data elements. This is
190 * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
191 */
192#ifdef _KERNEL
193#if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
194 defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
195 defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
196#define SIZEOF_BPF_HDR 18
197#define SIZEOF_BPF_HDR32 18
198#else
199#define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
200#define SIZEOF_BPF_HDR32 sizeof(struct bpf_hdr32)
201#endif
202#endif
203
204/* Pull in data-link level type codes. */
205#include <net/dlt.h>
206
207/*
208 * The instruction encodings.
209 */
210/* instruction classes */
211#define BPF_CLASS(code) ((code) & 0x07)
212#define BPF_LD 0x00
213#define BPF_LDX 0x01
214#define BPF_ST 0x02
215#define BPF_STX 0x03
216#define BPF_ALU 0x04
217#define BPF_JMP 0x05
218#define BPF_RET 0x06
219#define BPF_MISC 0x07
220
221/* ld/ldx fields */
222#define BPF_SIZE(code) ((code) & 0x18)
223#define BPF_W 0x00
224#define BPF_H 0x08
225#define BPF_B 0x10
226/* 0x18 reserved; used by BSD/OS */
227#define BPF_MODE(code) ((code) & 0xe0)
228#define BPF_IMM 0x00
229#define BPF_ABS 0x20
230#define BPF_IND 0x40
231#define BPF_MEM 0x60
232#define BPF_LEN 0x80
233#define BPF_MSH 0xa0
234/* 0xc0 reserved; used by BSD/OS */
235/* 0xe0 reserved; used by BSD/OS */
236
237/* alu/jmp fields */
238#define BPF_OP(code) ((code) & 0xf0)
239#define BPF_ADD 0x00
240#define BPF_SUB 0x10
241#define BPF_MUL 0x20
242#define BPF_DIV 0x30
243#define BPF_OR 0x40
244#define BPF_AND 0x50
245#define BPF_LSH 0x60
246#define BPF_RSH 0x70
247#define BPF_NEG 0x80
248#define BPF_MOD 0x90
249#define BPF_XOR 0xa0
250/* 0xb0 reserved */
251/* 0xc0 reserved */
252/* 0xd0 reserved */
253/* 0xe0 reserved */
254/* 0xf0 reserved */
255#define BPF_JA 0x00
256#define BPF_JEQ 0x10
257#define BPF_JGT 0x20
258#define BPF_JGE 0x30
259#define BPF_JSET 0x40
260/* 0x50 reserved; used by BSD/OS */
261/* 0x60 reserved */
262/* 0x70 reserved */
263/* 0x80 reserved */
264/* 0x90 reserved */
265/* 0xa0 reserved */
266/* 0xb0 reserved */
267/* 0xc0 reserved */
268/* 0xd0 reserved */
269/* 0xe0 reserved */
270/* 0xf0 reserved */
271#define BPF_SRC(code) ((code) & 0x08)
272#define BPF_K 0x00
273#define BPF_X 0x08
274
275/* ret - BPF_K and BPF_X also apply */
276#define BPF_RVAL(code) ((code) & 0x18)
277#define BPF_A 0x10
278/* 0x18 reserved */
279
280/* misc */
281#define BPF_MISCOP(code) ((code) & 0xf8)
282#define BPF_TAX 0x00
283/* 0x10 reserved */
284/* 0x18 reserved */
285#define BPF_COP 0x20
286/* 0x28 reserved */
287/* 0x30 reserved */
288/* 0x38 reserved */
289#define BPF_COPX 0x40 /* XXX: also used by BSD/OS */
290/* 0x48 reserved */
291/* 0x50 reserved */
292/* 0x58 reserved */
293/* 0x60 reserved */
294/* 0x68 reserved */
295/* 0x70 reserved */
296/* 0x78 reserved */
297#define BPF_TXA 0x80
298/* 0x88 reserved */
299/* 0x90 reserved */
300/* 0x98 reserved */
301/* 0xa0 reserved */
302/* 0xa8 reserved */
303/* 0xb0 reserved */
304/* 0xb8 reserved */
305/* 0xc0 reserved; used by BSD/OS */
306/* 0xc8 reserved */
307/* 0xd0 reserved */
308/* 0xd8 reserved */
309/* 0xe0 reserved */
310/* 0xe8 reserved */
311/* 0xf0 reserved */
312/* 0xf8 reserved */
313
314/*
315 * The instruction data structure.
316 */
317struct bpf_insn {
318 uint16_t code;
319 u_char jt;
320 u_char jf;
321 uint32_t k;
322};
323
324/*
325 * Macros for insn array initializers.
326 */
327#define BPF_STMT(code, k) { (uint16_t)(code), 0, 0, k }
328#define BPF_JUMP(code, k, jt, jf) { (uint16_t)(code), jt, jf, k }
329
330/*
331 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
332 */
333#define BPF_MEMWORDS 16
334
335/*
336 * bpf_memword_init_t: bits indicate which words in the external memory
337 * store will be initialised by the caller before BPF program execution.
338 */
339typedef uint32_t bpf_memword_init_t;
340#define BPF_MEMWORD_INIT(k) (UINT32_C(1) << (k))
341
342/* Note: two most significant bits are reserved by bpfjit. */
343__CTASSERT(BPF_MEMWORDS + 2 <= sizeof(bpf_memword_init_t) * NBBY);
344
345#ifdef _KERNEL
346/*
347 * Max number of external memory words (for BPF_LD|BPF_MEM and BPF_ST).
348 */
349#define BPF_MAX_MEMWORDS 30
350
351__CTASSERT(BPF_MAX_MEMWORDS >= BPF_MEMWORDS);
352__CTASSERT(BPF_MAX_MEMWORDS + 2 <= sizeof(bpf_memword_init_t) * NBBY);
353#endif
354
355/*
356 * Structure to retrieve available DLTs for the interface.
357 */
358struct bpf_dltlist {
359 u_int bfl_len; /* number of bfd_list array */
360 u_int *bfl_list; /* array of DLTs */
361};
362
363struct bpf_ctx;
364typedef struct bpf_ctx bpf_ctx_t;
365
366typedef struct bpf_args {
367 const uint8_t * pkt;
368 size_t wirelen;
369 size_t buflen;
370 /*
371 * The following arguments are used only by some kernel
372 * subsystems.
373 * They aren't required for classical bpf filter programs.
374 * For such programs, bpfjit generated code doesn't read
375 * those arguments at all. Note however that bpf interpreter
376 * always needs a pointer to memstore.
377 */
378 uint32_t * mem; /* pointer to external memory store */
379 void * arg; /* auxiliary argument for a copfunc */
380} bpf_args_t;
381
382#if defined(_KERNEL) || defined(__BPF_PRIVATE)
383
384typedef uint32_t (*bpf_copfunc_t)(const bpf_ctx_t *, bpf_args_t *, uint32_t);
385
386struct bpf_ctx {
387 /*
388 * BPF coprocessor functions and the number of them.
389 */
390 const bpf_copfunc_t * copfuncs;
391 size_t nfuncs;
392
393 /*
394 * The number of memory words in the external memory store.
395 * There may be up to BPF_MAX_MEMWORDS words; if zero is set,
396 * then the internal memory store is used which has a fixed
397 * number of words (BPF_MEMWORDS).
398 */
399 size_t extwords;
400
401 /*
402 * The bitmask indicating which words in the external memstore
403 * will be initialised by the caller.
404 */
405 bpf_memword_init_t preinited;
406};
407#endif
408
409#ifdef _KERNEL
410#include <net/bpfjit.h>
411#include <net/if.h>
412
413struct bpf_if;
414
415struct bpf_ops {
416 void (*bpf_attach)(struct ifnet *, u_int, u_int, struct bpf_if **);
417 void (*bpf_detach)(struct ifnet *);
418 void (*bpf_change_type)(struct ifnet *, u_int, u_int);
419
420 void (*bpf_tap)(struct bpf_if *, u_char *, u_int);
421 void (*bpf_mtap)(struct bpf_if *, struct mbuf *);
422 void (*bpf_mtap2)(struct bpf_if *, void *, u_int, struct mbuf *);
423 void (*bpf_mtap_af)(struct bpf_if *, uint32_t, struct mbuf *);
424 void (*bpf_mtap_sl_in)(struct bpf_if *, u_char *, struct mbuf **);
425 void (*bpf_mtap_sl_out)(struct bpf_if *, u_char *, struct mbuf *);
426};
427
428extern struct bpf_ops *bpf_ops;
429
430static inline void
431bpf_attach(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
432{
433 bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, &_ifp->if_bpf);
434}
435
436static inline void
437bpf_attach2(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen, struct bpf_if **_dp)
438{
439 bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, _dp);
440}
441
442static inline void
443bpf_tap(struct ifnet *_ifp, u_char *_pkt, u_int _len)
444{
445 if (_ifp->if_bpf)
446 bpf_ops->bpf_tap(_ifp->if_bpf, _pkt, _len);
447}
448
449static inline void
450bpf_mtap(struct ifnet *_ifp, struct mbuf *_m)
451{
452 if (_ifp->if_bpf)
453 bpf_ops->bpf_mtap(_ifp->if_bpf, _m);
454}
455
456static inline void
457bpf_mtap2(struct bpf_if *_bpf, void *_data, u_int _dlen, struct mbuf *_m)
458{
459 bpf_ops->bpf_mtap2(_bpf, _data, _dlen, _m);
460}
461
462static inline void
463bpf_mtap3(struct bpf_if *_bpf, struct mbuf *_m)
464{
465 if (_bpf)
466 bpf_ops->bpf_mtap(_bpf, _m);
467}
468
469static inline void
470bpf_mtap_af(struct ifnet *_ifp, uint32_t _af, struct mbuf *_m)
471{
472 if (_ifp->if_bpf)
473 bpf_ops->bpf_mtap_af(_ifp->if_bpf, _af, _m);
474}
475
476static inline void
477bpf_change_type(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
478{
479 bpf_ops->bpf_change_type(_ifp, _dlt, _hdrlen);
480}
481
482static inline void
483bpf_detach(struct ifnet *_ifp)
484{
485 bpf_ops->bpf_detach(_ifp);
486}
487
488static inline void
489bpf_mtap_sl_in(struct ifnet *_ifp, u_char *_hdr, struct mbuf **_m)
490{
491 bpf_ops->bpf_mtap_sl_in(_ifp->if_bpf, _hdr, _m);
492}
493
494static inline void
495bpf_mtap_sl_out(struct ifnet *_ifp, u_char *_hdr, struct mbuf *_m)
496{
497 if (_ifp->if_bpf)
498 bpf_ops->bpf_mtap_sl_out(_ifp->if_bpf, _hdr, _m);
499}
500
501
502void bpf_setops(void);
503
504void bpf_ops_handover_enter(struct bpf_ops *);
505void bpf_ops_handover_exit(void);
506
507void bpfilterattach(int);
508
509bpf_ctx_t *bpf_create(void);
510void bpf_destroy(bpf_ctx_t *);
511
512int bpf_set_cop(bpf_ctx_t *, const bpf_copfunc_t *, size_t);
513int bpf_set_extmem(bpf_ctx_t *, size_t, bpf_memword_init_t);
514u_int bpf_filter_ext(const bpf_ctx_t *, const struct bpf_insn *, bpf_args_t *);
515int bpf_validate_ext(const bpf_ctx_t *, const struct bpf_insn *, int);
516
517bpfjit_func_t bpf_jit_generate(bpf_ctx_t *, void *, size_t);
518void bpf_jit_freecode(bpfjit_func_t);
519
520#endif
521
522int bpf_validate(const struct bpf_insn *, int);
523u_int bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int);
524
525__END_DECLS
526
527#endif /* !_NET_BPF_H_ */
528