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/_eventhandler.h>
41 #include <sys/ck.h>
42 #include <net/dlt.h>
43
44 /* BSD style release date */
45 #define BPF_RELEASE 199606
46
47 typedef int32_t bpf_int32;
48 typedef u_int32_t bpf_u_int32;
49 typedef int64_t bpf_int64;
50 typedef u_int64_t bpf_u_int64;
51 struct ifnet;
52
53 /*
54 * Alignment macros. BPF_WORDALIGN rounds up to the next multiple of
55 * BPF_ALIGNMENT.
56 */
57 #define BPF_ALIGNMENT sizeof(long)
58 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
59
60 #define BPF_MAXINSNS 512
61 #define BPF_MAXBUFSIZE 0x80000
62 #define BPF_MINBUFSIZE 32
63
64 /*
65 * Structure for BIOCSETF.
66 */
67 struct bpf_program {
68 u_int bf_len;
69 struct bpf_insn *bf_insns;
70 };
71
72 /*
73 * Struct returned by BIOCGSTATS.
74 */
75 struct bpf_stat {
76 u_int bs_recv; /* number of packets received */
77 u_int bs_drop; /* number of packets dropped */
78 };
79
80 /*
81 * Struct return by BIOCVERSION. This represents the version number of
82 * the filter language described by the instruction encodings below.
83 * bpf understands a program iff kernel_major == filter_major &&
84 * kernel_minor >= filter_minor, that is, if the value returned by the
85 * running kernel has the same major number and a minor number equal
86 * equal to or less than the filter being downloaded. Otherwise, the
87 * results are undefined, meaning an error may be returned or packets
88 * may be accepted haphazardly.
89 * It has nothing to do with the source code version.
90 */
91 struct bpf_version {
92 u_short bv_major;
93 u_short bv_minor;
94 };
95 /* Current version number of filter architecture. */
96 #define BPF_MAJOR_VERSION 1
97 #define BPF_MINOR_VERSION 1
98
99 /*
100 * Historically, BPF has supported a single buffering model, first using mbuf
101 * clusters in kernel, and later using malloc(9) buffers in kernel. We now
102 * support multiple buffering modes, which may be queried and set using
103 * BIOCGETBUFMODE and BIOCSETBUFMODE. So as to avoid handling the complexity
104 * of changing modes while sniffing packets, the mode becomes fixed once an
105 * interface has been attached to the BPF descriptor.
106 */
107 #define BPF_BUFMODE_BUFFER 1 /* Kernel buffers with read(). */
108 #define BPF_BUFMODE_ZBUF 2 /* Zero-copy buffers. */
109
110 /*-
111 * Struct used by BIOCSETZBUF, BIOCROTZBUF: describes up to two zero-copy
112 * buffer as used by BPF.
113 */
114 struct bpf_zbuf {
115 void *bz_bufa; /* Location of 'a' zero-copy buffer. */
116 void *bz_bufb; /* Location of 'b' zero-copy buffer. */
117 size_t bz_buflen; /* Size of zero-copy buffers. */
118 };
119
120 #define BIOCGBLEN _IOR('B', 102, u_int)
121 #define BIOCSBLEN _IOWR('B', 102, u_int)
122 #define BIOCSETF _IOW('B', 103, struct bpf_program)
123 #define BIOCFLUSH _IO('B', 104)
124 #define BIOCPROMISC _IO('B', 105)
125 #define BIOCGDLT _IOR('B', 106, u_int)
126 #define BIOCGETIF _IOR('B', 107, struct ifreq)
127 #define BIOCSETIF _IOW('B', 108, struct ifreq)
128 #define BIOCSRTIMEOUT _IOW('B', 109, struct timeval)
129 #define BIOCGRTIMEOUT _IOR('B', 110, struct timeval)
130 #define BIOCGSTATS _IOR('B', 111, struct bpf_stat)
131 #define BIOCIMMEDIATE _IOW('B', 112, u_int)
132 #define BIOCVERSION _IOR('B', 113, struct bpf_version)
133 #define BIOCGRSIG _IOR('B', 114, u_int)
134 #define BIOCSRSIG _IOW('B', 115, u_int)
135 #define BIOCGHDRCMPLT _IOR('B', 116, u_int)
136 #define BIOCSHDRCMPLT _IOW('B', 117, u_int)
137 #define BIOCGDIRECTION _IOR('B', 118, u_int)
138 #define BIOCSDIRECTION _IOW('B', 119, u_int)
139 #define BIOCSDLT _IOW('B', 120, u_int)
140 #define BIOCGDLTLIST _IOWR('B', 121, struct bpf_dltlist)
141 #define BIOCLOCK _IO('B', 122)
142 #define BIOCSETWF _IOW('B', 123, struct bpf_program)
143 #define BIOCFEEDBACK _IOW('B', 124, u_int)
144 #define BIOCGETBUFMODE _IOR('B', 125, u_int)
145 #define BIOCSETBUFMODE _IOW('B', 126, u_int)
146 #define BIOCGETZMAX _IOR('B', 127, size_t)
147 #define BIOCROTZBUF _IOR('B', 128, struct bpf_zbuf)
148 #define BIOCSETZBUF _IOW('B', 129, struct bpf_zbuf)
149 #define BIOCSETFNR _IOW('B', 130, struct bpf_program)
150 #define BIOCGTSTAMP _IOR('B', 131, u_int)
151 #define BIOCSTSTAMP _IOW('B', 132, u_int)
152 #define BIOCSETVLANPCP _IOW('B', 133, u_int)
153
154 /* Obsolete */
155 #define BIOCGSEESENT BIOCGDIRECTION
156 #define BIOCSSEESENT BIOCSDIRECTION
157
158 /* Packet directions */
159 enum bpf_direction {
160 BPF_D_IN, /* See incoming packets */
161 BPF_D_INOUT, /* See incoming and outgoing packets */
162 BPF_D_OUT /* See outgoing packets */
163 };
164
165 /* Time stamping functions */
166 #define BPF_T_MICROTIME 0x0000
167 #define BPF_T_NANOTIME 0x0001
168 #define BPF_T_BINTIME 0x0002
169 #define BPF_T_NONE 0x0003
170 #define BPF_T_FORMAT_MASK 0x0003
171 #define BPF_T_NORMAL 0x0000
172 #define BPF_T_FAST 0x0100
173 #define BPF_T_MONOTONIC 0x0200
174 #define BPF_T_MONOTONIC_FAST (BPF_T_FAST | BPF_T_MONOTONIC)
175 #define BPF_T_FLAG_MASK 0x0300
176 #define BPF_T_FORMAT(t) ((t) & BPF_T_FORMAT_MASK)
177 #define BPF_T_FLAG(t) ((t) & BPF_T_FLAG_MASK)
178 #define BPF_T_VALID(t) \
179 ((t) == BPF_T_NONE || (BPF_T_FORMAT(t) != BPF_T_NONE && \
180 ((t) & ~(BPF_T_FORMAT_MASK | BPF_T_FLAG_MASK)) == 0))
181
182 #define BPF_T_MICROTIME_FAST (BPF_T_MICROTIME | BPF_T_FAST)
183 #define BPF_T_NANOTIME_FAST (BPF_T_NANOTIME | BPF_T_FAST)
184 #define BPF_T_BINTIME_FAST (BPF_T_BINTIME | BPF_T_FAST)
185 #define BPF_T_MICROTIME_MONOTONIC (BPF_T_MICROTIME | BPF_T_MONOTONIC)
186 #define BPF_T_NANOTIME_MONOTONIC (BPF_T_NANOTIME | BPF_T_MONOTONIC)
187 #define BPF_T_BINTIME_MONOTONIC (BPF_T_BINTIME | BPF_T_MONOTONIC)
188 #define BPF_T_MICROTIME_MONOTONIC_FAST (BPF_T_MICROTIME | BPF_T_MONOTONIC_FAST)
189 #define BPF_T_NANOTIME_MONOTONIC_FAST (BPF_T_NANOTIME | BPF_T_MONOTONIC_FAST)
190 #define BPF_T_BINTIME_MONOTONIC_FAST (BPF_T_BINTIME | BPF_T_MONOTONIC_FAST)
191
192 /*
193 * Structure prepended to each packet.
194 */
195 struct bpf_ts {
196 bpf_int64 bt_sec; /* seconds */
197 bpf_u_int64 bt_frac; /* fraction */
198 };
199 struct bpf_xhdr {
200 struct bpf_ts bh_tstamp; /* time stamp */
201 bpf_u_int32 bh_caplen; /* length of captured portion */
202 bpf_u_int32 bh_datalen; /* original length of packet */
203 u_short bh_hdrlen; /* length of bpf header (this struct
204 plus alignment padding) */
205 };
206 /* Obsolete */
207 struct bpf_hdr {
208 struct timeval bh_tstamp; /* time stamp */
209 bpf_u_int32 bh_caplen; /* length of captured portion */
210 bpf_u_int32 bh_datalen; /* original length of packet */
211 u_short bh_hdrlen; /* length of bpf header (this struct
212 plus alignment padding) */
213 };
214 #ifdef _KERNEL
215 #define MTAG_BPF 0x627066
216 #define MTAG_BPF_TIMESTAMP 0
217 #endif
218
219 /*
220 * When using zero-copy BPF buffers, a shared memory header is present
221 * allowing the kernel BPF implementation and user process to synchronize
222 * without using system calls. This structure defines that header. When
223 * accessing these fields, appropriate atomic operation and memory barriers
224 * are required in order not to see stale or out-of-order data; see bpf(4)
225 * for reference code to access these fields from userspace.
226 *
227 * The layout of this structure is critical, and must not be changed; if must
228 * fit in a single page on all architectures.
229 */
230 struct bpf_zbuf_header {
231 volatile u_int bzh_kernel_gen; /* Kernel generation number. */
232 volatile u_int bzh_kernel_len; /* Length of data in the buffer. */
233 volatile u_int bzh_user_gen; /* User generation number. */
234 u_int _bzh_pad[5];
235 };
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 CK_LIST_HEAD(bpfd_list, bpf_d);
411
412 struct bpf_if_ext {
413 CK_LIST_ENTRY(bpf_if) bif_next; /* list of all interfaces */
414 struct bpfd_list bif_dlist; /* descriptor list */
415 };
416
417 void bpf_bufheld(struct bpf_d *d);
418 int bpf_validate(const struct bpf_insn *, int);
419 void bpf_tap(struct bpf_if *, u_char *, u_int);
420 void bpf_tap_if(struct ifnet *, u_char *, u_int);
421 void bpf_mtap(struct bpf_if *, struct mbuf *);
422 void bpf_mtap_if(struct ifnet *, struct mbuf *);
423 void bpf_mtap2(struct bpf_if *, void *, u_int, struct mbuf *);
424 void bpf_mtap2_if(struct ifnet *, void *, u_int, struct mbuf *);
425 void bpfattach(struct ifnet *, u_int, u_int);
426 void bpfattach2(struct ifnet *, u_int, u_int, struct bpf_if **);
427 void bpfdetach(struct ifnet *);
428 bool bpf_peers_present_if(struct ifnet *);
429 #ifdef VIMAGE
430 int bpf_get_bp_params(struct bpf_if *, u_int *, u_int *);
431 #endif
432
433 void bpfilterattach(int);
434 u_int bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
435
436 static __inline int
bpf_peers_present(struct bpf_if * bpf)437 bpf_peers_present(struct bpf_if *bpf)
438 {
439 struct bpf_if_ext *ext;
440
441 ext = (struct bpf_if_ext *)bpf;
442 if (!CK_LIST_EMPTY(&ext->bif_dlist))
443 return (1);
444 return (0);
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
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