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
48typedef int32_t bpf_int32;
49typedef u_int32_t bpf_u_int32;
50typedef int64_t bpf_int64;
51typedef u_int64_t bpf_u_int64;
52struct 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 */
68struct bpf_program {
69 u_int bf_len;
70 struct bpf_insn *bf_insns;
71};
72
73/*
74 * Struct returned by BIOCGSTATS.
75 */
76struct 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 */
92struct 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 */
115struct 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 */
160enum 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 */
196struct bpf_ts {
197 bpf_int64 bt_sec; /* seconds */
198 bpf_u_int64 bt_frac; /* fraction */
199};
200struct 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 */
208struct 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 */
231struct 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 */
361struct 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 */
377struct 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
384MALLOC_DECLARE(M_BPF);
385#endif
386#ifdef SYSCTL_DECL
387SYSCTL_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 */
410struct bpf_if;
411CK_LIST_HEAD(bpfd_list, bpf_d);
412
413struct 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
418void bpf_bufheld(struct bpf_d *d);
419int bpf_validate(const struct bpf_insn *, int);
420void bpf_tap(struct bpf_if *, u_char *, u_int);
421void bpf_tap_if(struct ifnet *, u_char *, u_int);
422void bpf_mtap(struct bpf_if *, struct mbuf *);
423void bpf_mtap_if(struct ifnet *, struct mbuf *);
424void bpf_mtap2(struct bpf_if *, void *, u_int, struct mbuf *);
425void bpf_mtap2_if(struct ifnet *, void *, u_int, struct mbuf *);
426void bpfattach(struct ifnet *, u_int, u_int);
427void bpfattach2(struct ifnet *, u_int, u_int, struct bpf_if **);
428void bpfdetach(struct ifnet *);
429bool bpf_peers_present_if(struct ifnet *);
430#ifdef VIMAGE
431int bpf_get_bp_params(struct bpf_if *, u_int *, u_int *);
432void bpf_ifdetach(struct ifnet *);
433#endif
434
435void bpfilterattach(int);
436u_int bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
437
438static __inline bool
439bpf_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 */
461typedef void (*bpf_track_fn)(void *, struct ifnet *, int /* dlt */,
462 int /* 1 =>'s attach */);
463EVENTHANDLER_DECLARE(bpf_track, bpf_track_fn);
464
465#endif /* _NET_BPF_H_ */