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
37 #ifndef _NET_BPF_H_
38 #define _NET_BPF_H_
39
40 #include <sys/types.h>
41 #include <sys/_eventhandler.h>
42 #include <sys/ck.h>
43 #include <net/dlt.h>
44
45 /* BSD style release date */
46 #define BPF_RELEASE 199606
47
48 typedef int32_t bpf_int32;
49 typedef u_int32_t bpf_u_int32;
50 typedef int64_t bpf_int64;
51 typedef u_int64_t bpf_u_int64;
52 struct ifnet;
53
54 /*
55 * Alignment macros. BPF_WORDALIGN rounds up to the next multiple of
56 * BPF_ALIGNMENT.
57 */
58 #define BPF_ALIGNMENT sizeof(long)
59 #define BPF_WORDALIGN(x) (((x) + (BPF_ALIGNMENT - 1)) & ~(BPF_ALIGNMENT - 1))
60
61 #define BPF_MAXINSNS 512
62 #define BPF_MAXBUFSIZE 0x80000
63 #define BPF_MINBUFSIZE 32
64
65 /*
66 * Structure for BIOCSETF.
67 */
68 struct bpf_program {
69 u_int bf_len;
70 struct bpf_insn *bf_insns;
71 };
72
73 /*
74 * Struct returned by BIOCGSTATS.
75 */
76 struct bpf_stat {
77 u_int bs_recv; /* number of packets received */
78 u_int bs_drop; /* number of packets dropped */
79 };
80
81 /*
82 * Struct return by BIOCVERSION. This represents the version number of
83 * the filter language described by the instruction encodings below.
84 * bpf understands a program iff kernel_major == filter_major &&
85 * kernel_minor >= filter_minor, that is, if the value returned by the
86 * running kernel has the same major number and a minor number equal
87 * equal to or less than the filter being downloaded. Otherwise, the
88 * results are undefined, meaning an error may be returned or packets
89 * may be accepted haphazardly.
90 * It has nothing to do with the source code version.
91 */
92 struct bpf_version {
93 u_short bv_major;
94 u_short bv_minor;
95 };
96 /* Current version number of filter architecture. */
97 #define BPF_MAJOR_VERSION 1
98 #define BPF_MINOR_VERSION 1
99
100 /*
101 * Historically, BPF has supported a single buffering model, first using mbuf
102 * clusters in kernel, and later using malloc(9) buffers in kernel. We now
103 * support multiple buffering modes, which may be queried and set using
104 * BIOCGETBUFMODE and BIOCSETBUFMODE. So as to avoid handling the complexity
105 * of changing modes while sniffing packets, the mode becomes fixed once an
106 * interface has been attached to the BPF descriptor.
107 */
108 #define BPF_BUFMODE_BUFFER 1 /* Kernel buffers with read(). */
109 #define BPF_BUFMODE_ZBUF 2 /* Zero-copy buffers. */
110
111 /*-
112 * Struct used by BIOCSETZBUF, BIOCROTZBUF: describes up to two zero-copy
113 * buffer as used by BPF.
114 */
115 struct bpf_zbuf {
116 void *bz_bufa; /* Location of 'a' zero-copy buffer. */
117 void *bz_bufb; /* Location of 'b' zero-copy buffer. */
118 size_t bz_buflen; /* Size of zero-copy buffers. */
119 };
120
121 #define BIOCGBLEN _IOR('B', 102, u_int)
122 #define BIOCSBLEN _IOWR('B', 102, u_int)
123 #define BIOCSETF _IOW('B', 103, struct bpf_program)
124 #define BIOCFLUSH _IO('B', 104)
125 #define BIOCPROMISC _IO('B', 105)
126 #define BIOCGDLT _IOR('B', 106, u_int)
127 #define BIOCGETIF _IOR('B', 107, struct ifreq)
128 #define BIOCSETIF _IOW('B', 108, struct ifreq)
129 #define BIOCSRTIMEOUT _IOW('B', 109, struct timeval)
130 #define BIOCGRTIMEOUT _IOR('B', 110, struct timeval)
131 #define BIOCGSTATS _IOR('B', 111, struct bpf_stat)
132 #define BIOCIMMEDIATE _IOW('B', 112, u_int)
133 #define BIOCVERSION _IOR('B', 113, struct bpf_version)
134 #define BIOCGRSIG _IOR('B', 114, u_int)
135 #define BIOCSRSIG _IOW('B', 115, u_int)
136 #define BIOCGHDRCMPLT _IOR('B', 116, u_int)
137 #define BIOCSHDRCMPLT _IOW('B', 117, u_int)
138 #define BIOCGDIRECTION _IOR('B', 118, u_int)
139 #define BIOCSDIRECTION _IOW('B', 119, u_int)
140 #define BIOCSDLT _IOW('B', 120, u_int)
141 #define BIOCGDLTLIST _IOWR('B', 121, struct bpf_dltlist)
142 #define BIOCLOCK _IO('B', 122)
143 #define BIOCSETWF _IOW('B', 123, struct bpf_program)
144 #define BIOCFEEDBACK _IOW('B', 124, u_int)
145 #define BIOCGETBUFMODE _IOR('B', 125, u_int)
146 #define BIOCSETBUFMODE _IOW('B', 126, u_int)
147 #define BIOCGETZMAX _IOR('B', 127, size_t)
148 #define BIOCROTZBUF _IOR('B', 128, struct bpf_zbuf)
149 #define BIOCSETZBUF _IOW('B', 129, struct bpf_zbuf)
150 #define BIOCSETFNR _IOW('B', 130, struct bpf_program)
151 #define BIOCGTSTAMP _IOR('B', 131, u_int)
152 #define BIOCSTSTAMP _IOW('B', 132, u_int)
153 #define BIOCSETVLANPCP _IOW('B', 133, u_int)
154
155 /* Obsolete */
156 #define BIOCGSEESENT BIOCGDIRECTION
157 #define BIOCSSEESENT BIOCSDIRECTION
158
159 /* Packet directions */
160 enum bpf_direction {
161 BPF_D_IN, /* See incoming packets */
162 BPF_D_INOUT, /* See incoming and outgoing packets */
163 BPF_D_OUT /* See outgoing packets */
164 };
165
166 /* Time stamping functions */
167 #define BPF_T_MICROTIME 0x0000
168 #define BPF_T_NANOTIME 0x0001
169 #define BPF_T_BINTIME 0x0002
170 #define BPF_T_NONE 0x0003
171 #define BPF_T_FORMAT_MASK 0x0003
172 #define BPF_T_NORMAL 0x0000
173 #define BPF_T_FAST 0x0100
174 #define BPF_T_MONOTONIC 0x0200
175 #define BPF_T_MONOTONIC_FAST (BPF_T_FAST | BPF_T_MONOTONIC)
176 #define BPF_T_FLAG_MASK 0x0300
177 #define BPF_T_FORMAT(t) ((t) & BPF_T_FORMAT_MASK)
178 #define BPF_T_FLAG(t) ((t) & BPF_T_FLAG_MASK)
179 #define BPF_T_VALID(t) \
180 ((t) == BPF_T_NONE || (BPF_T_FORMAT(t) != BPF_T_NONE && \
181 ((t) & ~(BPF_T_FORMAT_MASK | BPF_T_FLAG_MASK)) == 0))
182
183 #define BPF_T_MICROTIME_FAST (BPF_T_MICROTIME | BPF_T_FAST)
184 #define BPF_T_NANOTIME_FAST (BPF_T_NANOTIME | BPF_T_FAST)
185 #define BPF_T_BINTIME_FAST (BPF_T_BINTIME | BPF_T_FAST)
186 #define BPF_T_MICROTIME_MONOTONIC (BPF_T_MICROTIME | BPF_T_MONOTONIC)
187 #define BPF_T_NANOTIME_MONOTONIC (BPF_T_NANOTIME | BPF_T_MONOTONIC)
188 #define BPF_T_BINTIME_MONOTONIC (BPF_T_BINTIME | BPF_T_MONOTONIC)
189 #define BPF_T_MICROTIME_MONOTONIC_FAST (BPF_T_MICROTIME | BPF_T_MONOTONIC_FAST)
190 #define BPF_T_NANOTIME_MONOTONIC_FAST (BPF_T_NANOTIME | BPF_T_MONOTONIC_FAST)
191 #define BPF_T_BINTIME_MONOTONIC_FAST (BPF_T_BINTIME | BPF_T_MONOTONIC_FAST)
192
193 /*
194 * Structure prepended to each packet.
195 */
196 struct bpf_ts {
197 bpf_int64 bt_sec; /* seconds */
198 bpf_u_int64 bt_frac; /* fraction */
199 };
200 struct bpf_xhdr {
201 struct bpf_ts bh_tstamp; /* time stamp */
202 bpf_u_int32 bh_caplen; /* length of captured portion */
203 bpf_u_int32 bh_datalen; /* original length of packet */
204 u_short bh_hdrlen; /* length of bpf header (this struct
205 plus alignment padding) */
206 };
207 /* Obsolete */
208 struct bpf_hdr {
209 struct timeval bh_tstamp; /* time stamp */
210 bpf_u_int32 bh_caplen; /* length of captured portion */
211 bpf_u_int32 bh_datalen; /* original length of packet */
212 u_short bh_hdrlen; /* length of bpf header (this struct
213 plus alignment padding) */
214 };
215 #ifdef _KERNEL
216 #define MTAG_BPF 0x627066
217 #define MTAG_BPF_TIMESTAMP 0
218 #endif
219
220 /*
221 * When using zero-copy BPF buffers, a shared memory header is present
222 * allowing the kernel BPF implementation and user process to synchronize
223 * without using system calls. This structure defines that header. When
224 * accessing these fields, appropriate atomic operation and memory barriers
225 * are required in order not to see stale or out-of-order data; see bpf(4)
226 * for reference code to access these fields from userspace.
227 *
228 * The layout of this structure is critical, and must not be changed; if must
229 * fit in a single page on all architectures.
230 */
231 struct bpf_zbuf_header {
232 volatile u_int bzh_kernel_gen; /* Kernel generation number. */
233 volatile u_int bzh_kernel_len; /* Length of data in the buffer. */
234 volatile u_int bzh_user_gen; /* User generation number. */
235 u_int _bzh_pad[5];
236 };
237
238 /*
239 * The instruction encodings.
240 *
241 * Please inform tcpdump-workers@lists.tcpdump.org if you use any
242 * of the reserved values, so that we can note that they're used
243 * (and perhaps implement it in the reference BPF implementation
244 * and encourage its implementation elsewhere).
245 */
246
247 /*
248 * The upper 8 bits of the opcode aren't used. BSD/OS used 0x8000.
249 */
250
251 /* instruction classes */
252 #define BPF_CLASS(code) ((code) & 0x07)
253 #define BPF_LD 0x00
254 #define BPF_LDX 0x01
255 #define BPF_ST 0x02
256 #define BPF_STX 0x03
257 #define BPF_ALU 0x04
258 #define BPF_JMP 0x05
259 #define BPF_RET 0x06
260 #define BPF_MISC 0x07
261
262 /* ld/ldx fields */
263 #define BPF_SIZE(code) ((code) & 0x18)
264 #define BPF_W 0x00
265 #define BPF_H 0x08
266 #define BPF_B 0x10
267 /* 0x18 reserved; used by BSD/OS */
268 #define BPF_MODE(code) ((code) & 0xe0)
269 #define BPF_IMM 0x00
270 #define BPF_ABS 0x20
271 #define BPF_IND 0x40
272 #define BPF_MEM 0x60
273 #define BPF_LEN 0x80
274 #define BPF_MSH 0xa0
275 /* 0xc0 reserved; used by BSD/OS */
276 /* 0xe0 reserved; used by BSD/OS */
277
278 /* alu/jmp fields */
279 #define BPF_OP(code) ((code) & 0xf0)
280 #define BPF_ADD 0x00
281 #define BPF_SUB 0x10
282 #define BPF_MUL 0x20
283 #define BPF_DIV 0x30
284 #define BPF_OR 0x40
285 #define BPF_AND 0x50
286 #define BPF_LSH 0x60
287 #define BPF_RSH 0x70
288 #define BPF_NEG 0x80
289 #define BPF_MOD 0x90
290 #define BPF_XOR 0xa0
291 /* 0xb0 reserved */
292 /* 0xc0 reserved */
293 /* 0xd0 reserved */
294 /* 0xe0 reserved */
295 /* 0xf0 reserved */
296
297 #define BPF_JA 0x00
298 #define BPF_JEQ 0x10
299 #define BPF_JGT 0x20
300 #define BPF_JGE 0x30
301 #define BPF_JSET 0x40
302 /* 0x50 reserved; used on BSD/OS */
303 /* 0x60 reserved */
304 /* 0x70 reserved */
305 /* 0x80 reserved */
306 /* 0x90 reserved */
307 /* 0xa0 reserved */
308 /* 0xb0 reserved */
309 /* 0xc0 reserved */
310 /* 0xd0 reserved */
311 /* 0xe0 reserved */
312 /* 0xf0 reserved */
313 #define BPF_SRC(code) ((code) & 0x08)
314 #define BPF_K 0x00
315 #define BPF_X 0x08
316
317 /* ret - BPF_K and BPF_X also apply */
318 #define BPF_RVAL(code) ((code) & 0x18)
319 #define BPF_A 0x10
320 /* 0x18 reserved */
321
322 /* misc */
323 #define BPF_MISCOP(code) ((code) & 0xf8)
324 #define BPF_TAX 0x00
325 /* 0x08 reserved */
326 /* 0x10 reserved */
327 /* 0x18 reserved */
328 /* #define BPF_COP 0x20 NetBSD "coprocessor" extensions */
329 /* 0x28 reserved */
330 /* 0x30 reserved */
331 /* 0x38 reserved */
332 /* #define BPF_COPX 0x40 NetBSD "coprocessor" extensions */
333 /* also used on BSD/OS */
334 /* 0x48 reserved */
335 /* 0x50 reserved */
336 /* 0x58 reserved */
337 /* 0x60 reserved */
338 /* 0x68 reserved */
339 /* 0x70 reserved */
340 /* 0x78 reserved */
341 #define BPF_TXA 0x80
342 /* 0x88 reserved */
343 /* 0x90 reserved */
344 /* 0x98 reserved */
345 /* 0xa0 reserved */
346 /* 0xa8 reserved */
347 /* 0xb0 reserved */
348 /* 0xb8 reserved */
349 /* 0xc0 reserved; used on BSD/OS */
350 /* 0xc8 reserved */
351 /* 0xd0 reserved */
352 /* 0xd8 reserved */
353 /* 0xe0 reserved */
354 /* 0xe8 reserved */
355 /* 0xf0 reserved */
356 /* 0xf8 reserved */
357
358 /*
359 * The instruction data structure.
360 */
361 struct bpf_insn {
362 u_short code;
363 u_char jt;
364 u_char jf;
365 bpf_u_int32 k;
366 };
367
368 /*
369 * Macros for insn array initializers.
370 */
371 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
372 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
373
374 /*
375 * Structure to retrieve available DLTs for the interface.
376 */
377 struct bpf_dltlist {
378 u_int bfl_len; /* number of bfd_list array */
379 u_int *bfl_list; /* array of DLTs */
380 };
381
382 #ifdef _KERNEL
383 #ifdef MALLOC_DECLARE
384 MALLOC_DECLARE(M_BPF);
385 #endif
386 #ifdef SYSCTL_DECL
387 SYSCTL_DECL(_net_bpf);
388 #endif
389
390 /*
391 * Rotate the packet buffers in descriptor d. Move the store buffer into the
392 * hold slot, and the free buffer into the store slot. Zero the length of the
393 * new store buffer. Descriptor lock should be held. One must be careful to
394 * not rotate the buffers twice, i.e. if fbuf != NULL.
395 */
396 #define ROTATE_BUFFERS(d) do { \
397 (d)->bd_hbuf = (d)->bd_sbuf; \
398 (d)->bd_hlen = (d)->bd_slen; \
399 (d)->bd_sbuf = (d)->bd_fbuf; \
400 (d)->bd_slen = 0; \
401 (d)->bd_fbuf = NULL; \
402 bpf_bufheld(d); \
403 } while (0)
404
405 /*
406 * Descriptor associated with each attached hardware interface.
407 * Part of this structure is exposed to external callers to speed up
408 * bpf_peers_present() calls.
409 */
410 struct bpf_if;
411 CK_LIST_HEAD(bpfd_list, bpf_d);
412
413 struct bpf_if_ext {
414 CK_LIST_ENTRY(bpf_if) bif_next; /* list of all interfaces */
415 struct bpfd_list bif_dlist; /* descriptor list */
416 };
417
418 void bpf_bufheld(struct bpf_d *d);
419 int bpf_validate(const struct bpf_insn *, int);
420 void bpf_tap(struct bpf_if *, u_char *, u_int);
421 void bpf_tap_if(struct ifnet *, u_char *, u_int);
422 void bpf_mtap(struct bpf_if *, struct mbuf *);
423 void bpf_mtap_if(struct ifnet *, struct mbuf *);
424 void bpf_mtap2(struct bpf_if *, void *, u_int, struct mbuf *);
425 void bpf_mtap2_if(struct ifnet *, void *, u_int, struct mbuf *);
426 void bpfattach(struct ifnet *, u_int, u_int);
427 void bpfattach2(struct ifnet *, u_int, u_int, struct bpf_if **);
428 void bpfdetach(struct ifnet *);
429 bool bpf_peers_present_if(struct ifnet *);
430 #ifdef VIMAGE
431 int bpf_get_bp_params(struct bpf_if *, u_int *, u_int *);
432 void bpf_ifdetach(struct ifnet *);
433 #endif
434
435 void bpfilterattach(int);
436 u_int bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
437
438 static __inline bool
bpf_peers_present(struct bpf_if * bpf)439 bpf_peers_present(struct bpf_if *bpf)
440 {
441 struct bpf_if_ext *ext;
442
443 ext = (struct bpf_if_ext *)bpf;
444 return (!CK_LIST_EMPTY(&ext->bif_dlist));
445 }
446
447 #define BPF_TAP(_ifp, _pkt, _pktlen) \
448 bpf_tap_if((_ifp), (_pkt), (_pktlen))
449 #define BPF_MTAP(_ifp, _m) \
450 bpf_mtap_if((_ifp), (_m))
451 #define BPF_MTAP2(_ifp, _data, _dlen, _m) \
452 bpf_mtap2_if((_ifp), (_data), (_dlen), (_m))
453 #endif /* _KERNEL */
454
455 /*
456 * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
457 */
458 #define BPF_MEMWORDS 16
459
460 /* BPF attach/detach events */
461 typedef void (*bpf_track_fn)(void *, struct ifnet *, int /* dlt */,
462 int /* 1 =>'s attach */);
463 EVENTHANDLER_DECLARE(bpf_track, bpf_track_fn);
464
465 #endif /* _NET_BPF_H_ */
466