FreeBSD/Linux Kernel Cross Reference
sys/net/bpf.h
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 * 4. 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 * $FreeBSD$
38 */
39
40 #ifndef _NET_BPF_H_
41 #define _NET_BPF_H_
42
43 /* BSD style release date */
44 #define BPF_RELEASE 199606
45
46 typedef int32_t bpf_int32;
47 typedef u_int32_t bpf_u_int32;
48 typedef int64_t bpf_int64;
49 typedef u_int64_t bpf_u_int64;
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_MAXBUFSIZE 0x80000
60 #define BPF_MINBUFSIZE 32
61
62 /*
63 * Structure for BIOCSETF.
64 */
65 struct bpf_program {
66 u_int bf_len;
67 struct bpf_insn *bf_insns;
68 };
69
70 /*
71 * Struct returned by BIOCGSTATS.
72 */
73 struct bpf_stat {
74 u_int bs_recv; /* number of packets received */
75 u_int bs_drop; /* number of packets dropped */
76 };
77
78 /*
79 * Struct return by BIOCVERSION. This represents the version number of
80 * the filter language described by the instruction encodings below.
81 * bpf understands a program iff kernel_major == filter_major &&
82 * kernel_minor >= filter_minor, that is, if the value returned by the
83 * running kernel has the same major number and a minor number equal
84 * equal to or less than the filter being downloaded. Otherwise, the
85 * results are undefined, meaning an error may be returned or packets
86 * may be accepted haphazardly.
87 * It has nothing to do with the source code version.
88 */
89 struct bpf_version {
90 u_short bv_major;
91 u_short bv_minor;
92 };
93 /* Current version number of filter architecture. */
94 #define BPF_MAJOR_VERSION 1
95 #define BPF_MINOR_VERSION 1
96
97 /*
98 * Historically, BPF has supported a single buffering model, first using mbuf
99 * clusters in kernel, and later using malloc(9) buffers in kernel. We now
100 * support multiple buffering modes, which may be queried and set using
101 * BIOCGETBUFMODE and BIOCSETBUFMODE. So as to avoid handling the complexity
102 * of changing modes while sniffing packets, the mode becomes fixed once an
103 * interface has been attached to the BPF descriptor.
104 */
105 #define BPF_BUFMODE_BUFFER 1 /* Kernel buffers with read(). */
106 #define BPF_BUFMODE_ZBUF 2 /* Zero-copy buffers. */
107
108 /*-
109 * Struct used by BIOCSETZBUF, BIOCROTZBUF: describes up to two zero-copy
110 * buffer as used by BPF.
111 */
112 struct bpf_zbuf {
113 void *bz_bufa; /* Location of 'a' zero-copy buffer. */
114 void *bz_bufb; /* Location of 'b' zero-copy buffer. */
115 size_t bz_buflen; /* Size of zero-copy buffers. */
116 };
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 #define BIOCSRTIMEOUT _IOW('B', 109, struct timeval)
127 #define BIOCGRTIMEOUT _IOR('B', 110, struct timeval)
128 #define BIOCGSTATS _IOR('B', 111, struct bpf_stat)
129 #define BIOCIMMEDIATE _IOW('B', 112, u_int)
130 #define BIOCVERSION _IOR('B', 113, struct bpf_version)
131 #define BIOCGRSIG _IOR('B', 114, u_int)
132 #define BIOCSRSIG _IOW('B', 115, u_int)
133 #define BIOCGHDRCMPLT _IOR('B', 116, u_int)
134 #define BIOCSHDRCMPLT _IOW('B', 117, u_int)
135 #define BIOCGDIRECTION _IOR('B', 118, u_int)
136 #define BIOCSDIRECTION _IOW('B', 119, u_int)
137 #define BIOCSDLT _IOW('B', 120, u_int)
138 #define BIOCGDLTLIST _IOWR('B', 121, struct bpf_dltlist)
139 #define BIOCLOCK _IO('B', 122)
140 #define BIOCSETWF _IOW('B', 123, struct bpf_program)
141 #define BIOCFEEDBACK _IOW('B', 124, u_int)
142 #define BIOCGETBUFMODE _IOR('B', 125, u_int)
143 #define BIOCSETBUFMODE _IOW('B', 126, u_int)
144 #define BIOCGETZMAX _IOR('B', 127, size_t)
145 #define BIOCROTZBUF _IOR('B', 128, struct bpf_zbuf)
146 #define BIOCSETZBUF _IOW('B', 129, struct bpf_zbuf)
147 #define BIOCSETFNR _IOW('B', 130, struct bpf_program)
148 #define BIOCGTSTAMP _IOR('B', 131, u_int)
149 #define BIOCSTSTAMP _IOW('B', 132, u_int)
150
151 /* Obsolete */
152 #define BIOCGSEESENT BIOCGDIRECTION
153 #define BIOCSSEESENT BIOCSDIRECTION
154
155 /* Packet directions */
156 enum bpf_direction {
157 BPF_D_IN, /* See incoming packets */
158 BPF_D_INOUT, /* See incoming and outgoing packets */
159 BPF_D_OUT /* See outgoing packets */
160 };
161
162 /* Time stamping functions */
163 #define BPF_T_MICROTIME 0x0000
164 #define BPF_T_NANOTIME 0x0001
165 #define BPF_T_BINTIME 0x0002
166 #define BPF_T_NONE 0x0003
167 #define BPF_T_FORMAT_MASK 0x0003
168 #define BPF_T_NORMAL 0x0000
169 #define BPF_T_FAST 0x0100
170 #define BPF_T_MONOTONIC 0x0200
171 #define BPF_T_MONOTONIC_FAST (BPF_T_FAST | BPF_T_MONOTONIC)
172 #define BPF_T_FLAG_MASK 0x0300
173 #define BPF_T_FORMAT(t) ((t) & BPF_T_FORMAT_MASK)
174 #define BPF_T_FLAG(t) ((t) & BPF_T_FLAG_MASK)
175 #define BPF_T_VALID(t) \
176 ((t) == BPF_T_NONE || (BPF_T_FORMAT(t) != BPF_T_NONE && \
177 ((t) & ~(BPF_T_FORMAT_MASK | BPF_T_FLAG_MASK)) == 0))
178
179 #define BPF_T_MICROTIME_FAST (BPF_T_MICROTIME | BPF_T_FAST)
180 #define BPF_T_NANOTIME_FAST (BPF_T_NANOTIME | BPF_T_FAST)
181 #define BPF_T_BINTIME_FAST (BPF_T_BINTIME | BPF_T_FAST)
182 #define BPF_T_MICROTIME_MONOTONIC (BPF_T_MICROTIME | BPF_T_MONOTONIC)
183 #define BPF_T_NANOTIME_MONOTONIC (BPF_T_NANOTIME | BPF_T_MONOTONIC)
184 #define BPF_T_BINTIME_MONOTONIC (BPF_T_BINTIME | BPF_T_MONOTONIC)
185 #define BPF_T_MICROTIME_MONOTONIC_FAST (BPF_T_MICROTIME | BPF_T_MONOTONIC_FAST)
186 #define BPF_T_NANOTIME_MONOTONIC_FAST (BPF_T_NANOTIME | BPF_T_MONOTONIC_FAST)
187 #define BPF_T_BINTIME_MONOTONIC_FAST (BPF_T_BINTIME | BPF_T_MONOTONIC_FAST)
188
189 /*
190 * Structure prepended to each packet.
191 */
192 struct bpf_ts {
193 bpf_int64 bt_sec; /* seconds */
194 bpf_u_int64 bt_frac; /* fraction */
195 };
196 struct bpf_xhdr {
197 struct bpf_ts bh_tstamp; /* time stamp */
198 bpf_u_int32 bh_caplen; /* length of captured portion */
199 bpf_u_int32 bh_datalen; /* original length of packet */
200 u_short bh_hdrlen; /* length of bpf header (this struct
201 plus alignment padding) */
202 };
203 /* Obsolete */
204 struct bpf_hdr {
205 struct timeval bh_tstamp; /* time stamp */
206 bpf_u_int32 bh_caplen; /* length of captured portion */
207 bpf_u_int32 bh_datalen; /* original length of packet */
208 u_short bh_hdrlen; /* length of bpf header (this struct
209 plus alignment padding) */
210 };
211 #ifdef _KERNEL
212 #define MTAG_BPF 0x627066
213 #define MTAG_BPF_TIMESTAMP 0
214 #endif
215
216 /*
217 * When using zero-copy BPF buffers, a shared memory header is present
218 * allowing the kernel BPF implementation and user process to synchronize
219 * without using system calls. This structure defines that header. When
220 * accessing these fields, appropriate atomic operation and memory barriers
221 * are required in order not to see stale or out-of-order data; see bpf(4)
222 * for reference code to access these fields from userspace.
223 *
224 * The layout of this structure is critical, and must not be changed; if must
225 * fit in a single page on all architectures.
226 */
227 struct bpf_zbuf_header {
228 volatile u_int bzh_kernel_gen; /* Kernel generation number. */
229 volatile u_int bzh_kernel_len; /* Length of data in the buffer. */
230 volatile u_int bzh_user_gen; /* User generation number. */
231 u_int _bzh_pad[5];
232 };
233
234 /* Pull in data-link level type codes. */
235 #include <net/dlt.h>
236
237 /*
238 * The instruction encodings.
239 *
240 * Please inform tcpdump-workers@lists.tcpdump.org if you use any
241 * of the reserved values, so that we can note that they're used
242 * (and perhaps implement it in the reference BPF implementation
243 * and encourage its implementation elsewhere).
244 */
245
246 /*
247 * The upper 8 bits of the opcode aren't used. BSD/OS used 0x8000.
248 */
249
250 /* instruction classes */
251 #define BPF_CLASS(code) ((code) & 0x07)
252 #define BPF_LD 0x00
253 #define BPF_LDX 0x01
254 #define BPF_ST 0x02
255 #define BPF_STX 0x03
256 #define BPF_ALU 0x04
257 #define BPF_JMP 0x05
258 #define BPF_RET 0x06
259 #define BPF_MISC 0x07
260
261 /* ld/ldx fields */
262 #define BPF_SIZE(code) ((code) & 0x18)
263 #define BPF_W 0x00
264 #define BPF_H 0x08
265 #define BPF_B 0x10
266 /* 0x18 reserved; used by BSD/OS */
267 #define BPF_MODE(code) ((code) & 0xe0)
268 #define BPF_IMM 0x00
269 #define BPF_ABS 0x20
270 #define BPF_IND 0x40
271 #define BPF_MEM 0x60
272 #define BPF_LEN 0x80
273 #define BPF_MSH 0xa0
274 /* 0xc0 reserved; used by BSD/OS */
275 /* 0xe0 reserved; used by BSD/OS */
276
277 /* alu/jmp fields */
278 #define BPF_OP(code) ((code) & 0xf0)
279 #define BPF_ADD 0x00
280 #define BPF_SUB 0x10
281 #define BPF_MUL 0x20
282 #define BPF_DIV 0x30
283 #define BPF_OR 0x40
284 #define BPF_AND 0x50
285 #define BPF_LSH 0x60
286 #define BPF_RSH 0x70
287 #define BPF_NEG 0x80
288 #define BPF_MOD 0x90
289 #define BPF_XOR 0xa0
290 /* 0xb0 reserved */
291 /* 0xc0 reserved */
292 /* 0xd0 reserved */
293 /* 0xe0 reserved */
294 /* 0xf0 reserved */
295
296 #define BPF_JA 0x00
297 #define BPF_JEQ 0x10
298 #define BPF_JGT 0x20
299 #define BPF_JGE 0x30
300 #define BPF_JSET 0x40
301 /* 0x50 reserved; used on BSD/OS */
302 /* 0x60 reserved */
303 /* 0x70 reserved */
304 /* 0x80 reserved */
305 /* 0x90 reserved */
306 /* 0xa0 reserved */
307 /* 0xb0 reserved */
308 /* 0xc0 reserved */
309 /* 0xd0 reserved */
310 /* 0xe0 reserved */
311 /* 0xf0 reserved */
312 #define BPF_SRC(code) ((code) & 0x08)
313 #define BPF_K 0x00
314 #define BPF_X 0x08
315
316 /* ret - BPF_K and BPF_X also apply */
317 #define BPF_RVAL(code) ((code) & 0x18)
318 #define BPF_A 0x10
319 /* 0x18 reserved */
320
321 /* misc */
322 #define BPF_MISCOP(code) ((code) & 0xf8)
323 #define BPF_TAX 0x00
324 /* 0x08 reserved */
325 /* 0x10 reserved */
326 /* 0x18 reserved */
327 /* #define BPF_COP 0x20 NetBSD "coprocessor" extensions */
328 /* 0x28 reserved */
329 /* 0x30 reserved */
330 /* 0x38 reserved */
331 /* #define BPF_COPX 0x40 NetBSD "coprocessor" extensions */
332 /* also used on BSD/OS */
333 /* 0x48 reserved */
334 /* 0x50 reserved */
335 /* 0x58 reserved */
336 /* 0x60 reserved */
337 /* 0x68 reserved */
338 /* 0x70 reserved */
339 /* 0x78 reserved */
340 #define BPF_TXA 0x80
341 /* 0x88 reserved */
342 /* 0x90 reserved */
343 /* 0x98 reserved */
344 /* 0xa0 reserved */
345 /* 0xa8 reserved */
346 /* 0xb0 reserved */
347 /* 0xb8 reserved */
348 /* 0xc0 reserved; used on BSD/OS */
349 /* 0xc8 reserved */
350 /* 0xd0 reserved */
351 /* 0xd8 reserved */
352 /* 0xe0 reserved */
353 /* 0xe8 reserved */
354 /* 0xf0 reserved */
355 /* 0xf8 reserved */
356
357 /*
358 * The instruction data structure.
359 */
360 struct bpf_insn {
361 u_short code;
362 u_char jt;
363 u_char jf;
364 bpf_u_int32 k;
365 };
366
367 /*
368 * Macros for insn array initializers.
369 */
370 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
371 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
372
373 /*
374 * Structure to retrieve available DLTs for the interface.
375 */
376 struct bpf_dltlist {
377 u_int bfl_len; /* number of bfd_list array */
378 u_int *bfl_list; /* array of DLTs */
379 };
380
381 #ifdef _KERNEL
382 #ifdef MALLOC_DECLARE
383 MALLOC_DECLARE(M_BPF);
384 #endif
385 #ifdef SYSCTL_DECL
386 SYSCTL_DECL(_net_bpf);
387 #endif
388
389 /*
390 * Rotate the packet buffers in descriptor d. Move the store buffer into the
391 * hold slot, and the free buffer into the store slot. Zero the length of the
392 * new store buffer. Descriptor lock should be held. One must be careful to
393 * not rotate the buffers twice, i.e. if fbuf != NULL.
394 */
395 #define ROTATE_BUFFERS(d) do { \
396 (d)->bd_hbuf = (d)->bd_sbuf; \
397 (d)->bd_hlen = (d)->bd_slen; \
398 (d)->bd_sbuf = (d)->bd_fbuf; \
399 (d)->bd_slen = 0; \
400 (d)->bd_fbuf = NULL; \
401 bpf_bufheld(d); \
402 } while (0)
403
404 /*
405 * Descriptor associated with each attached hardware interface.
406 * Part of this structure is exposed to external callers to speed up
407 * bpf_peers_present() calls.
408 */
409 struct bpf_if;
410
411 struct bpf_if_ext {
412 LIST_ENTRY(bpf_if) bif_next; /* list of all interfaces */
413 LIST_HEAD(, bpf_d) bif_dlist; /* descriptor list */
414 };
415
416 void bpf_bufheld(struct bpf_d *d);
417 int bpf_validate(const struct bpf_insn *, int);
418 void bpf_tap(struct bpf_if *, u_char *, u_int);
419 void bpf_mtap(struct bpf_if *, struct mbuf *);
420 void bpf_mtap2(struct bpf_if *, void *, u_int, struct mbuf *);
421 void bpfattach(struct ifnet *, u_int, u_int);
422 void bpfattach2(struct ifnet *, u_int, u_int, struct bpf_if **);
423 void bpfdetach(struct ifnet *);
424 #ifdef VIMAGE
425 int bpf_get_bp_params(struct bpf_if *, u_int *, u_int *);
426 #endif
427
428 void bpfilterattach(int);
429 u_int bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
430
431 static __inline int
432 bpf_peers_present(struct bpf_if *bpf)
433 {
434 struct bpf_if_ext *ext;
435
436 ext = (struct bpf_if_ext *)bpf;
437 if (!LIST_EMPTY(&ext->bif_dlist))
438 return (1);
439 return (0);
440 }
441
442 #define BPF_TAP(_ifp,_pkt,_pktlen) do { \
443 if (bpf_peers_present((_ifp)->if_bpf)) \
444 bpf_tap((_ifp)->if_bpf, (_pkt), (_pktlen)); \
445 } while (0)
446 #define BPF_MTAP(_ifp,_m) do { \
447 if (bpf_peers_present((_ifp)->if_bpf)) { \
448 M_ASSERTVALID(_m); \
449 bpf_mtap((_ifp)->if_bpf, (_m)); \
450 } \
451 } while (0)
452 #define BPF_MTAP2(_ifp,_data,_dlen,_m) do { \
453 if (bpf_peers_present((_ifp)->if_bpf)) { \
454 M_ASSERTVALID(_m); \
455 bpf_mtap2((_ifp)->if_bpf,(_data),(_dlen),(_m)); \
456 } \
457 } while (0)
458 #endif
459
460 /*
461 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
462 */
463 #define BPF_MEMWORDS 16
464
465 #ifdef _SYS_EVENTHANDLER_H_
466 /* BPF attach/detach events */
467 struct ifnet;
468 typedef void (*bpf_track_fn)(void *, struct ifnet *, int /* dlt */,
469 int /* 1 =>'s attach */);
470 EVENTHANDLER_DECLARE(bpf_track, bpf_track_fn);
471 #endif /* _SYS_EVENTHANDLER_H_ */
472
473 #endif /* _NET_BPF_H_ */
Cache object: d076dafc4d1b91f4df14a22873d84a5f
|