xref: /openbsd/sys/net/bpf.h (revision e88074f0)
1 /*	$OpenBSD: bpf.h,v 1.73 2024/08/15 12:20:20 dlg Exp $	*/
2 /*	$NetBSD: bpf.h,v 1.15 1996/12/13 07:57:33 mikel Exp $	*/
3 
4 /*
5  * Copyright (c) 1990, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from the Stanford/CMU enet packet filter,
9  * (net/enet.c) distributed as part of 4.3BSD, and code contributed
10  * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
11  * Berkeley Laboratory.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *	@(#)bpf.h	8.1 (Berkeley) 6/10/93
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 /*
49  * Alignment macros.  BPF_WORDALIGN rounds up to the next even multiple of
50  * BPF_ALIGNMENT (which is at least as much as what a timeval needs).
51  */
52 #define BPF_ALIGNMENT sizeof(u_int32_t)
53 #define BPF_WORDALIGN(x) (((x) + (BPF_ALIGNMENT - 1)) & ~(BPF_ALIGNMENT - 1))
54 
55 #define BPF_MAXINSNS 512
56 #define BPF_MAXBUFSIZE (2 * 1024 * 1024)
57 #define BPF_MINBUFSIZE 32
58 
59 /*
60  *  Structure for BIOCSETF.
61  */
62 struct bpf_program {
63 	u_int bf_len;
64 	struct bpf_insn *bf_insns;
65 };
66 
67 /*
68  * Struct returned by BIOCGSTATS.
69  */
70 struct bpf_stat {
71 	u_int bs_recv;		/* number of packets received */
72 	u_int bs_drop;		/* number of packets dropped */
73 };
74 
75 /*
76  * Struct return by BIOCVERSION.  This represents the version number of
77  * the filter language described by the instruction encodings below.
78  * bpf understands a program iff kernel_major == filter_major &&
79  * kernel_minor >= filter_minor, that is, if the value returned by the
80  * running kernel has the same major number and a minor number equal
81  * equal to or less than the filter being downloaded.  Otherwise, the
82  * results are undefined, meaning an error may be returned or packets
83  * may be accepted haphazardly.
84  * It has nothing to do with the source code version.
85  */
86 struct bpf_version {
87 	u_short bv_major;
88 	u_short bv_minor;
89 };
90 /* Current version number of filter architecture. */
91 #define BPF_MAJOR_VERSION 1
92 #define BPF_MINOR_VERSION 1
93 
94 /*
95  * BPF ioctls
96  */
97 #define	BIOCGBLEN	_IOR('B',102, u_int)
98 #define	BIOCSBLEN	_IOWR('B',102, u_int)
99 #define	BIOCSETF	_IOW('B',103, struct bpf_program)
100 #define	BIOCFLUSH	_IO('B',104)
101 #define BIOCPROMISC	_IO('B',105)
102 #define	BIOCGDLT	_IOR('B',106, u_int)
103 #define BIOCGETIF	_IOR('B',107, struct ifreq)
104 #define BIOCSETIF	_IOW('B',108, struct ifreq)
105 #define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
106 #define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
107 #define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
108 #define BIOCIMMEDIATE	_IOW('B',112, u_int)
109 #define BIOCVERSION	_IOR('B',113, struct bpf_version)
110 #define BIOCSRSIG	_IOW('B',114, u_int)
111 #define BIOCGRSIG	_IOR('B',115, u_int)
112 #define BIOCGHDRCMPLT	_IOR('B',116, u_int)
113 #define BIOCSHDRCMPLT	_IOW('B',117, u_int)
114 #define	BIOCLOCK	_IO('B',118)
115 #define	BIOCSETWF	_IOW('B',119, struct bpf_program)
116 #define BIOCGFILDROP	_IOR('B',120, u_int)
117 #define BIOCSFILDROP	_IOW('B',121, u_int)
118 #define BIOCSDLT	_IOW('B',122, u_int)
119 #define BIOCGDLTLIST	_IOWR('B',123, struct bpf_dltlist)
120 #define BIOCGDIRFILT	_IOR('B',124, u_int)
121 #define BIOCSDIRFILT	_IOW('B',125, u_int)
122 #define BIOCSWTIMEOUT	_IOW('B',126, struct timeval)
123 #define BIOCGWTIMEOUT	_IOR('B',126, struct timeval)
124 #define BIOCDWTIMEOUT	_IO('B',126)
125 #define BIOCSETFNR	_IOW('B',127, struct bpf_program)
126 
127 /*
128  * Direction filters for BIOCSDIRFILT/BIOCGDIRFILT
129  */
130 #define BPF_DIRECTION_IN	(1 << 0)
131 #define BPF_DIRECTION_OUT	(1 << 1)
132 
133 /*
134  * Values for BIOCGFILDROP/BIOCSFILDROP
135  */
136 #define BPF_FILDROP_PASS	0 /* capture, pass */
137 #define BPF_FILDROP_CAPTURE	1 /* capture, drop */
138 #define BPF_FILDROP_DROP	2 /* no capture, drop */
139 
140 struct bpf_timeval {
141 	u_int32_t	tv_sec;
142 	u_int32_t	tv_usec;
143 };
144 
145 /*
146  * Structure prepended to each packet.
147  */
148 struct bpf_hdr {
149 	struct bpf_timeval bh_tstamp;	/* time stamp */
150 	u_int32_t	bh_caplen;	/* length of captured portion */
151 	u_int32_t	bh_datalen;	/* original length of packet */
152 	u_int16_t	bh_hdrlen;	/* length of bpf header (this struct
153 					   plus alignment padding) */
154 	u_int16_t	bh_ifidx;	/* receive interface index */
155 
156 	u_int16_t	bh_flowid;
157 	u_int8_t	bh_flags;
158 #define BPF_F_PRI_MASK		0x07
159 #define BPF_F_FLOWID		0x08
160 #define BPF_F_DIR_SHIFT		4
161 #define BPF_F_DIR_MASK		(0x3 << BPF_F_DIR_SHIFT)
162 #define BPF_F_DIR_IN		(BPF_DIRECTION_IN << BPF_F_DIR_SHIFT)
163 #define BPF_F_DIR_OUT		(BPF_DIRECTION_OUT << BPF_F_DIR_SHIFT)
164 	u_int8_t	bh_drops;
165 	u_int16_t	bh_csumflags;	/* checksum flags */
166 };
167 
168 #ifdef _KERNEL
169 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
170 #endif
171 
172 /*
173  * Data-link level type codes.
174  */
175 #define DLT_NULL		0	/* no link-layer encapsulation */
176 #define DLT_EN10MB		1	/* Ethernet (10Mb) */
177 #define DLT_EN3MB		2	/* Experimental Ethernet (3Mb) */
178 #define DLT_AX25		3	/* Amateur Radio AX.25 */
179 #define DLT_PRONET		4	/* Proteon ProNET Token Ring */
180 #define DLT_CHAOS		5	/* Chaos */
181 #define DLT_IEEE802		6	/* IEEE 802 Networks */
182 #define DLT_ARCNET		7	/* ARCNET */
183 #define DLT_SLIP		8	/* Serial Line IP */
184 #define DLT_PPP			9	/* Point-to-point Protocol */
185 #define DLT_FDDI		10	/* FDDI */
186 #define DLT_ATM_RFC1483		11	/* LLC/SNAP encapsulated atm */
187 #define DLT_LOOP		12	/* loopback type (af header) */
188 #define DLT_ENC			13	/* IPSEC enc type (af header, spi, flags) */
189 #define DLT_RAW			14	/* raw IP */
190 #define DLT_SLIP_BSDOS		15	/* BSD/OS Serial Line IP */
191 #define DLT_PPP_BSDOS		16	/* BSD/OS Point-to-point Protocol */
192 #define DLT_PFSYNC		18	/* Packet filter state syncing */
193 #define DLT_PPP_SERIAL		50	/* PPP over Serial with HDLC */
194 #define DLT_PPP_ETHER		51	/* PPP over Ethernet; session only w/o ether header */
195 #define DLT_C_HDLC		104	/* Cisco HDLC */
196 #define DLT_IEEE802_11		105	/* IEEE 802.11 wireless */
197 #define DLT_PFLOG		117	/* Packet filter logging, by pcap people */
198 #define DLT_IEEE802_11_RADIO	127	/* IEEE 802.11 plus WLAN header */
199 #define DLT_USER0		147	/* Reserved for private use */
200 #define DLT_USER1		148	/* Reserved for private use */
201 #define DLT_USER2		149	/* Reserved for private use */
202 #define DLT_USER3		150	/* Reserved for private use */
203 #define DLT_USER4		151	/* Reserved for private use */
204 #define DLT_USER5		152	/* Reserved for private use */
205 #define DLT_USER6		153	/* Reserved for private use */
206 #define DLT_USER7		154	/* Reserved for private use */
207 #define DLT_USER8		155	/* Reserved for private use */
208 #define DLT_USER9		156	/* Reserved for private use */
209 #define DLT_USER10		157	/* Reserved for private use */
210 #define DLT_USER11		158	/* Reserved for private use */
211 #define DLT_USER12		159	/* Reserved for private use */
212 #define DLT_USER13		160	/* Reserved for private use */
213 #define DLT_USER14		161	/* Reserved for private use */
214 #define DLT_USER15		162	/* Reserved for private use */
215 #define DLT_USBPCAP		249	/* USBPcap */
216 #define DLT_MPLS		219	/* MPLS Provider Edge header */
217 #define DLT_OPENFLOW		267	/* in-kernel OpenFlow, by pcap */
218 
219 /*
220  * The instruction encodings.
221  */
222 /* instruction classes */
223 #define BPF_CLASS(code) ((code) & 0x07)
224 #define		BPF_LD		0x00
225 #define		BPF_LDX		0x01
226 #define		BPF_ST		0x02
227 #define		BPF_STX		0x03
228 #define		BPF_ALU		0x04
229 #define		BPF_JMP		0x05
230 #define		BPF_RET		0x06
231 #define		BPF_MISC	0x07
232 
233 /* ld/ldx fields */
234 #define BPF_SIZE(code)	((code) & 0x18)
235 #define		BPF_W		0x00
236 #define		BPF_H		0x08
237 #define		BPF_B		0x10
238 #define BPF_MODE(code)	((code) & 0xe0)
239 #define		BPF_IMM		0x00
240 #define		BPF_ABS		0x20
241 #define		BPF_IND		0x40
242 #define		BPF_MEM		0x60
243 #define		BPF_LEN		0x80
244 #define		BPF_MSH		0xa0
245 #define		BPF_RND		0xc0
246 
247 /* alu/jmp fields */
248 #define BPF_OP(code)	((code) & 0xf0)
249 #define		BPF_ADD		0x00
250 #define		BPF_SUB		0x10
251 #define		BPF_MUL		0x20
252 #define		BPF_DIV		0x30
253 #define		BPF_OR		0x40
254 #define		BPF_AND		0x50
255 #define		BPF_LSH		0x60
256 #define		BPF_RSH		0x70
257 #define		BPF_NEG		0x80
258 #define		BPF_JA		0x00
259 #define		BPF_JEQ		0x10
260 #define		BPF_JGT		0x20
261 #define		BPF_JGE		0x30
262 #define		BPF_JSET	0x40
263 #define BPF_SRC(code)	((code) & 0x08)
264 #define		BPF_K		0x00
265 #define		BPF_X		0x08
266 
267 /* ret - BPF_K and BPF_X also apply */
268 #define BPF_RVAL(code)	((code) & 0x18)
269 #define		BPF_A		0x10
270 
271 /* misc */
272 #define BPF_MISCOP(code) ((code) & 0xf8)
273 #define		BPF_TAX		0x00
274 #define		BPF_TXA		0x80
275 
276 /*
277  * The instruction data structure.
278  */
279 struct bpf_insn {
280 	u_int16_t	code;
281 	u_char		jt;
282 	u_char		jf;
283 	u_int32_t	k;
284 };
285 
286 /*
287  * Structure to retrieve available DLTs for the interface.
288  */
289 struct bpf_dltlist {
290 	u_int	bfl_len;	/* number of bfd_list array */
291 	u_int	*bfl_list;	/* array of DLTs */
292 };
293 
294 /*
295  * Load operations for _bpf_filter to use against the packet pointer.
296  */
297 struct bpf_ops {
298 	u_int32_t	(*ldw)(const void *, u_int32_t, int *);
299 	u_int32_t	(*ldh)(const void *, u_int32_t, int *);
300 	u_int32_t	(*ldb)(const void *, u_int32_t, int *);
301 };
302 
303 /*
304  * Macros for insn array initializers.
305  */
306 #define BPF_STMT(code, k) { (u_int16_t)(code), 0, 0, k }
307 #define BPF_JUMP(code, k, jt, jf) { (u_int16_t)(code), jt, jf, k }
308 
309 __BEGIN_DECLS
310 u_int	 bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int)
311 	    __bounded((__buffer__, 2, 4));
312 
313 u_int	 _bpf_filter(const struct bpf_insn *, const struct bpf_ops *,
314 	     const void *, u_int);
315 __END_DECLS
316 
317 #ifdef _KERNEL
318 struct ifnet;
319 struct mbuf;
320 
321 int	 bpf_validate(struct bpf_insn *, int);
322 int	 bpf_mtap(caddr_t, const struct mbuf *, u_int);
323 int	 bpf_mtap_hdr(caddr_t, const void *, u_int, const struct mbuf *, u_int);
324 int	 bpf_mtap_af(caddr_t, u_int32_t, const struct mbuf *, u_int);
325 int	 bpf_mtap_ether(caddr_t, const struct mbuf *, u_int);
326 int	 bpf_tap_hdr(caddr_t, const void *, u_int, const void *, u_int, u_int);
327 void	 bpfattach(caddr_t *, struct ifnet *, u_int, u_int);
328 void	 bpfdetach(struct ifnet *);
329 void	*bpfsattach(caddr_t *, const char *, u_int, u_int);
330 void	 bpfsdetach(void *);
331 void	 bpfilterattach(int);
332 
333 u_int	 bpf_mfilter(const struct bpf_insn *, const struct mbuf *, u_int);
334 #endif /* _KERNEL */
335 
336 /*
337  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
338  */
339 #define BPF_MEMWORDS 16
340 
341 #endif /* _NET_BPF_H_ */
342