1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 8.1 (Berkeley) 6/10/93
37 * @(#)bpf.h 1.34 (LBL) 6/16/96
38 *
39 * $FreeBSD$
40 */
41
42 #ifndef _NET_BPF_H_
43 #define _NET_BPF_H_
44
45 #include <sys/ck.h>
46 #include <net/dlt.h>
47
48 /* BSD style release date */
49 #define BPF_RELEASE 199606
50
51 typedef int32_t bpf_int32;
52 typedef u_int32_t bpf_u_int32;
53 typedef int64_t bpf_int64;
54 typedef u_int64_t bpf_u_int64;
55
56 /*
57 * Alignment macros. BPF_WORDALIGN rounds up to the next
58 * even multiple of BPF_ALIGNMENT.
59 */
60 #define BPF_ALIGNMENT sizeof(long)
61 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
62
63 #define BPF_MAXINSNS 512
64 #define BPF_MAXBUFSIZE 0x80000
65 #define BPF_MINBUFSIZE 32
66
67 /*
68 * Structure for BIOCSETF.
69 */
70 struct bpf_program {
71 u_int bf_len;
72 struct bpf_insn *bf_insns;
73 };
74
75 /*
76 * Struct returned by BIOCGSTATS.
77 */
78 struct bpf_stat {
79 u_int bs_recv; /* number of packets received */
80 u_int bs_drop; /* number of packets dropped */
81 };
82
83 /*
84 * Struct return by BIOCVERSION. This represents the version number of
85 * the filter language described by the instruction encodings below.
86 * bpf understands a program iff kernel_major == filter_major &&
87 * kernel_minor >= filter_minor, that is, if the value returned by the
88 * running kernel has the same major number and a minor number equal
89 * equal to or less than the filter being downloaded. Otherwise, the
90 * results are undefined, meaning an error may be returned or packets
91 * may be accepted haphazardly.
92 * It has nothing to do with the source code version.
93 */
94 struct bpf_version {
95 u_short bv_major;
96 u_short bv_minor;
97 };
98 /* Current version number of filter architecture. */
99 #define BPF_MAJOR_VERSION 1
100 #define BPF_MINOR_VERSION 1
101
102 /*
103 * Historically, BPF has supported a single buffering model, first using mbuf
104 * clusters in kernel, and later using malloc(9) buffers in kernel. We now
105 * support multiple buffering modes, which may be queried and set using
106 * BIOCGETBUFMODE and BIOCSETBUFMODE. So as to avoid handling the complexity
107 * of changing modes while sniffing packets, the mode becomes fixed once an
108 * interface has been attached to the BPF descriptor.
109 */
110 #define BPF_BUFMODE_BUFFER 1 /* Kernel buffers with read(). */
111 #define BPF_BUFMODE_ZBUF 2 /* Zero-copy buffers. */
112
113 /*-
114 * Struct used by BIOCSETZBUF, BIOCROTZBUF: describes up to two zero-copy
115 * buffer as used by BPF.
116 */
117 struct bpf_zbuf {
118 void *bz_bufa; /* Location of 'a' zero-copy buffer. */
119 void *bz_bufb; /* Location of 'b' zero-copy buffer. */
120 size_t bz_buflen; /* Size of zero-copy buffers. */
121 };
122
123 #define BIOCGBLEN _IOR('B', 102, u_int)
124 #define BIOCSBLEN _IOWR('B', 102, u_int)
125 #define BIOCSETF _IOW('B', 103, struct bpf_program)
126 #define BIOCFLUSH _IO('B', 104)
127 #define BIOCPROMISC _IO('B', 105)
128 #define BIOCGDLT _IOR('B', 106, u_int)
129 #define BIOCGETIF _IOR('B', 107, struct ifreq)
130 #define BIOCSETIF _IOW('B', 108, struct ifreq)
131 #define BIOCSRTIMEOUT _IOW('B', 109, struct timeval)
132 #define BIOCGRTIMEOUT _IOR('B', 110, struct timeval)
133 #define BIOCGSTATS _IOR('B', 111, struct bpf_stat)
134 #define BIOCIMMEDIATE _IOW('B', 112, u_int)
135 #define BIOCVERSION _IOR('B', 113, struct bpf_version)
136 #define BIOCGRSIG _IOR('B', 114, u_int)
137 #define BIOCSRSIG _IOW('B', 115, u_int)
138 #define BIOCGHDRCMPLT _IOR('B', 116, u_int)
139 #define BIOCSHDRCMPLT _IOW('B', 117, u_int)
140 #define BIOCGDIRECTION _IOR('B', 118, u_int)
141 #define BIOCSDIRECTION _IOW('B', 119, u_int)
142 #define BIOCSDLT _IOW('B', 120, u_int)
143 #define BIOCGDLTLIST _IOWR('B', 121, struct bpf_dltlist)
144 #define BIOCLOCK _IO('B', 122)
145 #define BIOCSETWF _IOW('B', 123, struct bpf_program)
146 #define BIOCFEEDBACK _IOW('B', 124, u_int)
147 #define BIOCGETBUFMODE _IOR('B', 125, u_int)
148 #define BIOCSETBUFMODE _IOW('B', 126, u_int)
149 #define BIOCGETZMAX _IOR('B', 127, size_t)
150 #define BIOCROTZBUF _IOR('B', 128, struct bpf_zbuf)
151 #define BIOCSETZBUF _IOW('B', 129, struct bpf_zbuf)
152 #define BIOCSETFNR _IOW('B', 130, struct bpf_program)
153 #define BIOCGTSTAMP _IOR('B', 131, u_int)
154 #define BIOCSTSTAMP _IOW('B', 132, u_int)
155
156 /* Obsolete */
157 #define BIOCGSEESENT BIOCGDIRECTION
158 #define BIOCSSEESENT BIOCSDIRECTION
159
160 /* Packet directions */
161 enum bpf_direction {
162 BPF_D_IN, /* See incoming packets */
163 BPF_D_INOUT, /* See incoming and outgoing packets */
164 BPF_D_OUT /* See outgoing packets */
165 };
166
167 /* Time stamping functions */
168 #define BPF_T_MICROTIME 0x0000
169 #define BPF_T_NANOTIME 0x0001
170 #define BPF_T_BINTIME 0x0002
171 #define BPF_T_NONE 0x0003
172 #define BPF_T_FORMAT_MASK 0x0003
173 #define BPF_T_NORMAL 0x0000
174 #define BPF_T_FAST 0x0100
175 #define BPF_T_MONOTONIC 0x0200
176 #define BPF_T_MONOTONIC_FAST (BPF_T_FAST | BPF_T_MONOTONIC)
177 #define BPF_T_FLAG_MASK 0x0300
178 #define BPF_T_FORMAT(t) ((t) & BPF_T_FORMAT_MASK)
179 #define BPF_T_FLAG(t) ((t) & BPF_T_FLAG_MASK)
180 #define BPF_T_VALID(t) \
181 ((t) == BPF_T_NONE || (BPF_T_FORMAT(t) != BPF_T_NONE && \
182 ((t) & ~(BPF_T_FORMAT_MASK | BPF_T_FLAG_MASK)) == 0))
183
184 #define BPF_T_MICROTIME_FAST (BPF_T_MICROTIME | BPF_T_FAST)
185 #define BPF_T_NANOTIME_FAST (BPF_T_NANOTIME | BPF_T_FAST)
186 #define BPF_T_BINTIME_FAST (BPF_T_BINTIME | BPF_T_FAST)
187 #define BPF_T_MICROTIME_MONOTONIC (BPF_T_MICROTIME | BPF_T_MONOTONIC)
188 #define BPF_T_NANOTIME_MONOTONIC (BPF_T_NANOTIME | BPF_T_MONOTONIC)
189 #define BPF_T_BINTIME_MONOTONIC (BPF_T_BINTIME | BPF_T_MONOTONIC)
190 #define BPF_T_MICROTIME_MONOTONIC_FAST (BPF_T_MICROTIME | BPF_T_MONOTONIC_FAST)
191 #define BPF_T_NANOTIME_MONOTONIC_FAST (BPF_T_NANOTIME | BPF_T_MONOTONIC_FAST)
192 #define BPF_T_BINTIME_MONOTONIC_FAST (BPF_T_BINTIME | BPF_T_MONOTONIC_FAST)
193
194 /*
195 * Structure prepended to each packet.
196 */
197 struct bpf_ts {
198 bpf_int64 bt_sec; /* seconds */
199 bpf_u_int64 bt_frac; /* fraction */
200 };
201 struct bpf_xhdr {
202 struct bpf_ts bh_tstamp; /* time stamp */
203 bpf_u_int32 bh_caplen; /* length of captured portion */
204 bpf_u_int32 bh_datalen; /* original length of packet */
205 u_short bh_hdrlen; /* length of bpf header (this struct
206 plus alignment padding) */
207 };
208 /* Obsolete */
209 struct bpf_hdr {
210 struct timeval bh_tstamp; /* time stamp */
211 bpf_u_int32 bh_caplen; /* length of captured portion */
212 bpf_u_int32 bh_datalen; /* original length of packet */
213 u_short bh_hdrlen; /* length of bpf header (this struct
214 plus alignment padding) */
215 };
216 #ifdef _KERNEL
217 #define MTAG_BPF 0x627066
218 #define MTAG_BPF_TIMESTAMP 0
219 #endif
220
221 /*
222 * When using zero-copy BPF buffers, a shared memory header is present
223 * allowing the kernel BPF implementation and user process to synchronize
224 * without using system calls. This structure defines that header. When
225 * accessing these fields, appropriate atomic operation and memory barriers
226 * are required in order not to see stale or out-of-order data; see bpf(4)
227 * for reference code to access these fields from userspace.
228 *
229 * The layout of this structure is critical, and must not be changed; if must
230 * fit in a single page on all architectures.
231 */
232 struct bpf_zbuf_header {
233 volatile u_int bzh_kernel_gen; /* Kernel generation number. */
234 volatile u_int bzh_kernel_len; /* Length of data in the buffer. */
235 volatile u_int bzh_user_gen; /* User generation number. */
236 u_int _bzh_pad[5];
237 };
238
239 /*
240 * The instruction encodings.
241 *
242 * Please inform [email protected] if you use any
243 * of the reserved values, so that we can note that they're used
244 * (and perhaps implement it in the reference BPF implementation
245 * and encourage its implementation elsewhere).
246 */
247
248 /*
249 * The upper 8 bits of the opcode aren't used. BSD/OS used 0x8000.
250 */
251
252 /* instruction classes */
253 #define BPF_CLASS(code) ((code) & 0x07)
254 #define BPF_LD 0x00
255 #define BPF_LDX 0x01
256 #define BPF_ST 0x02
257 #define BPF_STX 0x03
258 #define BPF_ALU 0x04
259 #define BPF_JMP 0x05
260 #define BPF_RET 0x06
261 #define BPF_MISC 0x07
262
263 /* ld/ldx fields */
264 #define BPF_SIZE(code) ((code) & 0x18)
265 #define BPF_W 0x00
266 #define BPF_H 0x08
267 #define BPF_B 0x10
268 /* 0x18 reserved; used by BSD/OS */
269 #define BPF_MODE(code) ((code) & 0xe0)
270 #define BPF_IMM 0x00
271 #define BPF_ABS 0x20
272 #define BPF_IND 0x40
273 #define BPF_MEM 0x60
274 #define BPF_LEN 0x80
275 #define BPF_MSH 0xa0
276 /* 0xc0 reserved; used by BSD/OS */
277 /* 0xe0 reserved; used by BSD/OS */
278
279 /* alu/jmp fields */
280 #define BPF_OP(code) ((code) & 0xf0)
281 #define BPF_ADD 0x00
282 #define BPF_SUB 0x10
283 #define BPF_MUL 0x20
284 #define BPF_DIV 0x30
285 #define BPF_OR 0x40
286 #define BPF_AND 0x50
287 #define BPF_LSH 0x60
288 #define BPF_RSH 0x70
289 #define BPF_NEG 0x80
290 #define BPF_MOD 0x90
291 #define BPF_XOR 0xa0
292 /* 0xb0 reserved */
293 /* 0xc0 reserved */
294 /* 0xd0 reserved */
295 /* 0xe0 reserved */
296 /* 0xf0 reserved */
297
298 #define BPF_JA 0x00
299 #define BPF_JEQ 0x10
300 #define BPF_JGT 0x20
301 #define BPF_JGE 0x30
302 #define BPF_JSET 0x40
303 /* 0x50 reserved; used on BSD/OS */
304 /* 0x60 reserved */
305 /* 0x70 reserved */
306 /* 0x80 reserved */
307 /* 0x90 reserved */
308 /* 0xa0 reserved */
309 /* 0xb0 reserved */
310 /* 0xc0 reserved */
311 /* 0xd0 reserved */
312 /* 0xe0 reserved */
313 /* 0xf0 reserved */
314 #define BPF_SRC(code) ((code) & 0x08)
315 #define BPF_K 0x00
316 #define BPF_X 0x08
317
318 /* ret - BPF_K and BPF_X also apply */
319 #define BPF_RVAL(code) ((code) & 0x18)
320 #define BPF_A 0x10
321 /* 0x18 reserved */
322
323 /* misc */
324 #define BPF_MISCOP(code) ((code) & 0xf8)
325 #define BPF_TAX 0x00
326 /* 0x08 reserved */
327 /* 0x10 reserved */
328 /* 0x18 reserved */
329 /* #define BPF_COP 0x20 NetBSD "coprocessor" extensions */
330 /* 0x28 reserved */
331 /* 0x30 reserved */
332 /* 0x38 reserved */
333 /* #define BPF_COPX 0x40 NetBSD "coprocessor" extensions */
334 /* also used on BSD/OS */
335 /* 0x48 reserved */
336 /* 0x50 reserved */
337 /* 0x58 reserved */
338 /* 0x60 reserved */
339 /* 0x68 reserved */
340 /* 0x70 reserved */
341 /* 0x78 reserved */
342 #define BPF_TXA 0x80
343 /* 0x88 reserved */
344 /* 0x90 reserved */
345 /* 0x98 reserved */
346 /* 0xa0 reserved */
347 /* 0xa8 reserved */
348 /* 0xb0 reserved */
349 /* 0xb8 reserved */
350 /* 0xc0 reserved; used on BSD/OS */
351 /* 0xc8 reserved */
352 /* 0xd0 reserved */
353 /* 0xd8 reserved */
354 /* 0xe0 reserved */
355 /* 0xe8 reserved */
356 /* 0xf0 reserved */
357 /* 0xf8 reserved */
358
359 /*
360 * The instruction data structure.
361 */
362 struct bpf_insn {
363 u_short code;
364 u_char jt;
365 u_char jf;
366 bpf_u_int32 k;
367 };
368
369 /*
370 * Macros for insn array initializers.
371 */
372 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
373 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
374
375 /*
376 * Structure to retrieve available DLTs for the interface.
377 */
378 struct bpf_dltlist {
379 u_int bfl_len; /* number of bfd_list array */
380 u_int *bfl_list; /* array of DLTs */
381 };
382
383 #ifdef _KERNEL
384 #ifdef MALLOC_DECLARE
385 MALLOC_DECLARE(M_BPF);
386 #endif
387 #ifdef SYSCTL_DECL
388 SYSCTL_DECL(_net_bpf);
389 #endif
390
391 /*
392 * Rotate the packet buffers in descriptor d. Move the store buffer into the
393 * hold slot, and the free buffer into the store slot. Zero the length of the
394 * new store buffer. Descriptor lock should be held. One must be careful to
395 * not rotate the buffers twice, i.e. if fbuf != NULL.
396 */
397 #define ROTATE_BUFFERS(d) do { \
398 (d)->bd_hbuf = (d)->bd_sbuf; \
399 (d)->bd_hlen = (d)->bd_slen; \
400 (d)->bd_sbuf = (d)->bd_fbuf; \
401 (d)->bd_slen = 0; \
402 (d)->bd_fbuf = NULL; \
403 bpf_bufheld(d); \
404 } while (0)
405
406 /*
407 * Descriptor associated with each attached hardware interface.
408 * Part of this structure is exposed to external callers to speed up
409 * bpf_peers_present() calls.
410 */
411 struct bpf_if;
412 CK_LIST_HEAD(bpfd_list, bpf_d);
413
414 struct bpf_if_ext {
415 CK_LIST_ENTRY(bpf_if) bif_next; /* list of all interfaces */
416 struct bpfd_list bif_dlist; /* descriptor list */
417 };
418
419 void bpf_bufheld(struct bpf_d *d);
420 int bpf_validate(const struct bpf_insn *, int);
421 void bpf_tap(struct bpf_if *, u_char *, u_int);
422 void bpf_mtap(struct bpf_if *, struct mbuf *);
423 void bpf_mtap2(struct bpf_if *, void *, u_int, struct mbuf *);
424 void bpfattach(struct ifnet *, u_int, u_int);
425 void bpfattach2(struct ifnet *, u_int, u_int, struct bpf_if **);
426 void bpfdetach(struct ifnet *);
427 #ifdef VIMAGE
428 int bpf_get_bp_params(struct bpf_if *, u_int *, u_int *);
429 #endif
430
431 void bpfilterattach(int);
432 u_int bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
433
434 static __inline int
bpf_peers_present(struct bpf_if * bpf)435 bpf_peers_present(struct bpf_if *bpf)
436 {
437 struct bpf_if_ext *ext;
438
439 ext = (struct bpf_if_ext *)bpf;
440 if (!CK_LIST_EMPTY(&ext->bif_dlist))
441 return (1);
442 return (0);
443 }
444
445 #define BPF_TAP(_ifp,_pkt,_pktlen) do { \
446 if (bpf_peers_present((_ifp)->if_bpf)) \
447 bpf_tap((_ifp)->if_bpf, (_pkt), (_pktlen)); \
448 } while (0)
449 #define BPF_MTAP(_ifp,_m) do { \
450 if (bpf_peers_present((_ifp)->if_bpf)) { \
451 M_ASSERTVALID(_m); \
452 bpf_mtap((_ifp)->if_bpf, (_m)); \
453 } \
454 } while (0)
455 #define BPF_MTAP2(_ifp,_data,_dlen,_m) do { \
456 if (bpf_peers_present((_ifp)->if_bpf)) { \
457 M_ASSERTVALID(_m); \
458 bpf_mtap2((_ifp)->if_bpf,(_data),(_dlen),(_m)); \
459 } \
460 } while (0)
461 #endif
462
463 /*
464 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
465 */
466 #define BPF_MEMWORDS 16
467
468 #ifdef _SYS_EVENTHANDLER_H_
469 /* BPF attach/detach events */
470 struct ifnet;
471 typedef void (*bpf_track_fn)(void *, struct ifnet *, int /* dlt */,
472 int /* 1 =>'s attach */);
473 EVENTHANDLER_DECLARE(bpf_track, bpf_track_fn);
474 #endif /* _SYS_EVENTHANDLER_H_ */
475
476 #endif /* _NET_BPF_H_ */
477