xref: /openbsd-src/sys/net/bpf.h (revision d59bb9942320b767f2a19aaa7690c8c6e30b724c)
1 /*	$OpenBSD: bpf.h,v 1.62 2017/02/22 09:56:03 reyk 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 
123 /*
124  * Direction filters for BIOCSDIRFILT/BIOCGDIRFILT
125  */
126 #define BPF_DIRECTION_IN	1
127 #define BPF_DIRECTION_OUT	(1<<1)
128 
129 struct bpf_timeval {
130 	u_int32_t	tv_sec;
131 	u_int32_t	tv_usec;
132 };
133 
134 /*
135  * Structure prepended to each packet.
136  */
137 struct bpf_hdr {
138 	struct bpf_timeval bh_tstamp;	/* time stamp */
139 	u_int32_t	bh_caplen;	/* length of captured portion */
140 	u_int32_t	bh_datalen;	/* original length of packet */
141 	u_int16_t	bh_hdrlen;	/* length of bpf header (this struct
142 					   plus alignment padding) */
143 };
144 /*
145  * Because the structure above is not a multiple of 4 bytes, some compilers
146  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
147  * Only the kernel needs to know about it; applications use bh_hdrlen.
148  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
149  * XXX padding by using the size of the header data elements.  This is
150  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
151  */
152 #ifdef _KERNEL
153 #if defined(__arm__) || defined(__i386__) || defined(__mips__) || \
154     defined(__sparc64__)
155 #define SIZEOF_BPF_HDR 18
156 #else
157 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
158 #endif
159 #endif
160 
161 /*
162  * Data-link level type codes.
163  */
164 #define DLT_NULL		0	/* no link-layer encapsulation */
165 #define DLT_EN10MB		1	/* Ethernet (10Mb) */
166 #define DLT_EN3MB		2	/* Experimental Ethernet (3Mb) */
167 #define DLT_AX25		3	/* Amateur Radio AX.25 */
168 #define DLT_PRONET		4	/* Proteon ProNET Token Ring */
169 #define DLT_CHAOS		5	/* Chaos */
170 #define DLT_IEEE802		6	/* IEEE 802 Networks */
171 #define DLT_ARCNET		7	/* ARCNET */
172 #define DLT_SLIP		8	/* Serial Line IP */
173 #define DLT_PPP			9	/* Point-to-point Protocol */
174 #define DLT_FDDI		10	/* FDDI */
175 #define DLT_ATM_RFC1483		11	/* LLC/SNAP encapsulated atm */
176 #define DLT_LOOP		12	/* loopback type (af header) */
177 #define DLT_ENC			13	/* IPSEC enc type (af header, spi, flags) */
178 #define DLT_RAW			14	/* raw IP */
179 #define DLT_SLIP_BSDOS		15	/* BSD/OS Serial Line IP */
180 #define DLT_PPP_BSDOS		16	/* BSD/OS Point-to-point Protocol */
181 #define DLT_PFSYNC		18	/* Packet filter state syncing */
182 #define DLT_PPP_SERIAL		50	/* PPP over Serial with HDLC */
183 #define DLT_PPP_ETHER		51	/* PPP over Ethernet; session only w/o ether header */
184 #define DLT_C_HDLC		104	/* Cisco HDLC */
185 #define DLT_IEEE802_11		105	/* IEEE 802.11 wireless */
186 #define DLT_PFLOG		117	/* Packet filter logging, by pcap people */
187 #define DLT_IEEE802_11_RADIO	127	/* IEEE 802.11 plus WLAN header */
188 #define DLT_USER0		147	/* Reserved for private use */
189 #define DLT_USER1		148	/* Reserved for private use */
190 #define DLT_USER2		149	/* Reserved for private use */
191 #define DLT_USER3		150	/* Reserved for private use */
192 #define DLT_USER4		151	/* Reserved for private use */
193 #define DLT_USER5		152	/* Reserved for private use */
194 #define DLT_USER6		153	/* Reserved for private use */
195 #define DLT_USER7		154	/* Reserved for private use */
196 #define DLT_USER8		155	/* Reserved for private use */
197 #define DLT_USER9		156	/* Reserved for private use */
198 #define DLT_USER10		157	/* Reserved for private use */
199 #define DLT_USER11		158	/* Reserved for private use */
200 #define DLT_USER12		159	/* Reserved for private use */
201 #define DLT_USER13		160	/* Reserved for private use */
202 #define DLT_USER14		161	/* Reserved for private use */
203 #define DLT_USER15		162	/* Reserved for private use */
204 #define DLT_MPLS		219	/* MPLS Provider Edge header */
205 #define DLT_OPENFLOW		267	/* in-kernel OpenFlow, by pcap */
206 
207 /*
208  * The instruction encodings.
209  */
210 /* instruction classes */
211 #define BPF_CLASS(code) ((code) & 0x07)
212 #define		BPF_LD		0x00
213 #define		BPF_LDX		0x01
214 #define		BPF_ST		0x02
215 #define		BPF_STX		0x03
216 #define		BPF_ALU		0x04
217 #define		BPF_JMP		0x05
218 #define		BPF_RET		0x06
219 #define		BPF_MISC	0x07
220 
221 /* ld/ldx fields */
222 #define BPF_SIZE(code)	((code) & 0x18)
223 #define		BPF_W		0x00
224 #define		BPF_H		0x08
225 #define		BPF_B		0x10
226 #define BPF_MODE(code)	((code) & 0xe0)
227 #define		BPF_IMM		0x00
228 #define		BPF_ABS		0x20
229 #define		BPF_IND		0x40
230 #define		BPF_MEM		0x60
231 #define		BPF_LEN		0x80
232 #define		BPF_MSH		0xa0
233 
234 /* alu/jmp fields */
235 #define BPF_OP(code)	((code) & 0xf0)
236 #define		BPF_ADD		0x00
237 #define		BPF_SUB		0x10
238 #define		BPF_MUL		0x20
239 #define		BPF_DIV		0x30
240 #define		BPF_OR		0x40
241 #define		BPF_AND		0x50
242 #define		BPF_LSH		0x60
243 #define		BPF_RSH		0x70
244 #define		BPF_NEG		0x80
245 #define		BPF_JA		0x00
246 #define		BPF_JEQ		0x10
247 #define		BPF_JGT		0x20
248 #define		BPF_JGE		0x30
249 #define		BPF_JSET	0x40
250 #define BPF_SRC(code)	((code) & 0x08)
251 #define		BPF_K		0x00
252 #define		BPF_X		0x08
253 
254 /* ret - BPF_K and BPF_X also apply */
255 #define BPF_RVAL(code)	((code) & 0x18)
256 #define		BPF_A		0x10
257 
258 /* misc */
259 #define BPF_MISCOP(code) ((code) & 0xf8)
260 #define		BPF_TAX		0x00
261 #define		BPF_TXA		0x80
262 
263 /*
264  * The instruction data structure.
265  */
266 struct bpf_insn {
267 	u_int16_t	code;
268 	u_char		jt;
269 	u_char		jf;
270 	u_int32_t	k;
271 };
272 
273 /*
274  * Structure to retrieve available DLTs for the interface.
275  */
276 struct bpf_dltlist {
277 	u_int	bfl_len;	/* number of bfd_list array */
278 	u_int	*bfl_list;	/* array of DLTs */
279 };
280 
281 /*
282  * Load operations for _bpf_filter to use against the packet pointer.
283  */
284 struct bpf_ops {
285 	u_int32_t	(*ldw)(const void *, u_int32_t, int *);
286 	u_int32_t	(*ldh)(const void *, u_int32_t, int *);
287 	u_int32_t	(*ldb)(const void *, u_int32_t, int *);
288 };
289 
290 /*
291  * Macros for insn array initializers.
292  */
293 #define BPF_STMT(code, k) { (u_int16_t)(code), 0, 0, k }
294 #define BPF_JUMP(code, k, jt, jf) { (u_int16_t)(code), jt, jf, k }
295 
296 __BEGIN_DECLS
297 u_int	 bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int)
298 	    __bounded((__buffer__, 2, 4));
299 
300 u_int	 _bpf_filter(const struct bpf_insn *, const struct bpf_ops *,
301 	     const void *, u_int);
302 __END_DECLS
303 
304 #ifdef _KERNEL
305 struct ifnet;
306 struct mbuf;
307 
308 int	 bpf_validate(struct bpf_insn *, int);
309 int	 bpf_mtap(caddr_t, const struct mbuf *, u_int);
310 int	 bpf_mtap_hdr(caddr_t, caddr_t, u_int, const struct mbuf *, u_int,
311 	    void (*)(const void *, void *, size_t));
312 int	 bpf_mtap_af(caddr_t, u_int32_t, const struct mbuf *, u_int);
313 int	 bpf_mtap_ether(caddr_t, const struct mbuf *, u_int);
314 void	 bpfattach(caddr_t *, struct ifnet *, u_int, u_int);
315 void	 bpfdetach(struct ifnet *);
316 void	 bpfilterattach(int);
317 
318 u_int	 bpf_mfilter(const struct bpf_insn *, const struct mbuf *, u_int);
319 #endif /* _KERNEL */
320 
321 /*
322  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
323  */
324 #define BPF_MEMWORDS 16
325 
326 #endif /* _NET_BPF_H_ */
327