xref: /netbsd-src/sys/net/bpf.h (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: bpf.h,v 1.41 2004/08/19 20:58:23 christos Exp $	*/
2 
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  *	@(#)bpf.h	8.2 (Berkeley) 1/9/95
37  * @(#) Header: bpf.h,v 1.36 97/06/12 14:29:53 leres Exp  (LBL)
38  */
39 
40 #ifndef _NET_BPF_H_
41 #define _NET_BPF_H_
42 
43 #include <sys/time.h>
44 
45 /* BSD style release date */
46 #define BPF_RELEASE 199606
47 
48 typedef	int bpf_int32;
49 typedef	u_int bpf_u_int32;
50 
51 /*
52  * Alignment macros.  BPF_WORDALIGN rounds up to the next
53  * even multiple of BPF_ALIGNMENT.
54  */
55 #define BPF_ALIGNMENT sizeof(long)
56 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
57 
58 #define BPF_MAXINSNS 512
59 #define BPF_DFLTBUFSIZE (1024*1024)	/* default static upper limit */
60 #define BPF_MAXBUFSIZE (1024*1024*16)	/* hard limit on sysctl'able value */
61 #define BPF_MINBUFSIZE 32
62 
63 /*
64  *  Structure for BIOCSETF.
65  */
66 struct bpf_program {
67 	u_int bf_len;
68 	struct bpf_insn *bf_insns;
69 };
70 
71 /*
72  * Struct returned by BIOCGSTATS.
73  */
74 struct bpf_stat {
75 	u_int64_t bs_recv;	/* number of packets received */
76 	u_int64_t bs_drop;	/* number of packets dropped */
77 	u_int64_t bs_capt;	/* number of packets captured */
78 	u_int64_t bs_padding[13];
79 };
80 
81 /*
82  * Struct returned by BIOCGSTATSOLD.
83  */
84 struct bpf_stat_old {
85 	u_int bs_recv;		/* number of packets received */
86 	u_int bs_drop;		/* number of packets dropped */
87 };
88 
89 /*
90  * Struct return by BIOCVERSION.  This represents the version number of
91  * the filter language described by the instruction encodings below.
92  * bpf understands a program iff kernel_major == filter_major &&
93  * kernel_minor >= filter_minor, that is, if the value returned by the
94  * running kernel has the same major number and a minor number equal
95  * equal to or less than the filter being downloaded.  Otherwise, the
96  * results are undefined, meaning an error may be returned or packets
97  * may be accepted haphazardly.
98  * It has nothing to do with the source code version.
99  */
100 struct bpf_version {
101 	u_short bv_major;
102 	u_short bv_minor;
103 };
104 /* Current version number of filter architecture. */
105 #define BPF_MAJOR_VERSION 1
106 #define BPF_MINOR_VERSION 1
107 
108 /*
109  * BPF ioctls
110  *
111  * The first set is for compatibility with Sun's pcc style
112  * header files.  If your using gcc, we assume that you
113  * have run fixincludes so the latter set should work.
114  */
115 #define BIOCGBLEN	 _IOR('B',102, u_int)
116 #define BIOCSBLEN	_IOWR('B',102, u_int)
117 #define BIOCSETF	 _IOW('B',103, struct bpf_program)
118 #define BIOCFLUSH	  _IO('B',104)
119 #define BIOCPROMISC	  _IO('B',105)
120 #define BIOCGDLT	 _IOR('B',106, u_int)
121 #define BIOCGETIF	 _IOR('B',107, struct ifreq)
122 #define BIOCSETIF	 _IOW('B',108, struct ifreq)
123 #define BIOCSRTIMEOUT	 _IOW('B',109, struct timeval)
124 #define BIOCGRTIMEOUT	 _IOR('B',110, struct timeval)
125 #define BIOCGSTATS	 _IOR('B',111, struct bpf_stat)
126 #define BIOCGSTATSOLD	 _IOR('B',111, struct bpf_stat_old)
127 #define BIOCIMMEDIATE	 _IOW('B',112, u_int)
128 #define BIOCVERSION	 _IOR('B',113, struct bpf_version)
129 #define BIOCSTCPF	 _IOW('B',114, struct bpf_program)
130 #define BIOCSUDPF	 _IOW('B',115, struct bpf_program)
131 #define BIOCGHDRCMPLT	 _IOR('B',116, u_int)
132 #define BIOCSHDRCMPLT	 _IOW('B',117, u_int)
133 #define BIOCSDLT	 _IOW('B',118, u_int)
134 #define BIOCGDLTLIST	_IOWR('B',119, struct bpf_dltlist)
135 #define BIOCGSEESENT	 _IOR('B',120, u_int)
136 #define BIOCSSEESENT	 _IOW('B',121, u_int)
137 
138 /*
139  * Structure prepended to each packet.
140  */
141 struct bpf_hdr {
142 	struct timeval	bh_tstamp;	/* time stamp */
143 	u_int32_t	bh_caplen;	/* length of captured portion */
144 	u_int32_t	bh_datalen;	/* original length of packet */
145 	u_int16_t	bh_hdrlen;	/* length of bpf header (this struct
146 					   plus alignment padding) */
147 };
148 /*
149  * Because the structure above is not a multiple of 4 bytes, some compilers
150  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
151  * Only the kernel needs to know about it; applications use bh_hdrlen.
152  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
153  * XXX padding by using the size of the header data elements.  This is
154  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
155  */
156 #ifdef _KERNEL
157 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
158     defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
159     defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
160 #define SIZEOF_BPF_HDR 18
161 #else
162 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
163 #endif
164 #endif
165 
166 /* Pull in data-link level type codes. */
167 #include <net/dlt.h>
168 
169 /*
170  * The instruction encondings.
171  */
172 /* instruction classes */
173 #define BPF_CLASS(code) ((code) & 0x07)
174 #define		BPF_LD		0x00
175 #define		BPF_LDX		0x01
176 #define		BPF_ST		0x02
177 #define		BPF_STX		0x03
178 #define		BPF_ALU		0x04
179 #define		BPF_JMP		0x05
180 #define		BPF_RET		0x06
181 #define		BPF_MISC	0x07
182 
183 /* ld/ldx fields */
184 #define BPF_SIZE(code)	((code) & 0x18)
185 #define		BPF_W		0x00
186 #define		BPF_H		0x08
187 #define		BPF_B		0x10
188 #define BPF_MODE(code)	((code) & 0xe0)
189 #define		BPF_IMM 	0x00
190 #define		BPF_ABS		0x20
191 #define		BPF_IND		0x40
192 #define		BPF_MEM		0x60
193 #define		BPF_LEN		0x80
194 #define		BPF_MSH		0xa0
195 
196 /* alu/jmp fields */
197 #define BPF_OP(code)	((code) & 0xf0)
198 #define		BPF_ADD		0x00
199 #define		BPF_SUB		0x10
200 #define		BPF_MUL		0x20
201 #define		BPF_DIV		0x30
202 #define		BPF_OR		0x40
203 #define		BPF_AND		0x50
204 #define		BPF_LSH		0x60
205 #define		BPF_RSH		0x70
206 #define		BPF_NEG		0x80
207 #define		BPF_JA		0x00
208 #define		BPF_JEQ		0x10
209 #define		BPF_JGT		0x20
210 #define		BPF_JGE		0x30
211 #define		BPF_JSET	0x40
212 #define BPF_SRC(code)	((code) & 0x08)
213 #define		BPF_K		0x00
214 #define		BPF_X		0x08
215 
216 /* ret - BPF_K and BPF_X also apply */
217 #define BPF_RVAL(code)	((code) & 0x18)
218 #define		BPF_A		0x10
219 
220 /* misc */
221 #define BPF_MISCOP(code) ((code) & 0xf8)
222 #define		BPF_TAX		0x00
223 #define		BPF_TXA		0x80
224 
225 /*
226  * The instruction data structure.
227  */
228 struct bpf_insn {
229 	u_int16_t code;
230 	u_char 	  jt;
231 	u_char 	  jf;
232 	int32_t	  k;
233 };
234 
235 /*
236  * Macros for insn array initializers.
237  */
238 #define BPF_STMT(code, k) { (u_int16_t)(code), 0, 0, k }
239 #define BPF_JUMP(code, k, jt, jf) { (u_int16_t)(code), jt, jf, k }
240 
241 /*
242  * Structure to retrieve available DLTs for the interface.
243  */
244 struct bpf_dltlist {
245 	u_int	bfl_len;	/* number of bfd_list array */
246 	u_int	*bfl_list;	/* array of DLTs */
247 };
248 
249 #ifdef _KERNEL
250 int	 bpf_validate(struct bpf_insn *, int);
251 void	 bpf_tap(void *, u_char *, u_int);
252 void	 bpf_mtap(void *, struct mbuf *);
253 void	 bpf_mtap2(void *, void *, u_int, struct mbuf *);
254 void	 bpf_mtap_af(void *, u_int32_t, struct mbuf *);
255 void	 bpf_mtap_et(void *, u_int16_t, struct mbuf *);
256 void	 bpf_mtap_sl_in(void *, u_char *, struct mbuf **);
257 void	 bpf_mtap_sl_out(void *, u_char *, struct mbuf *);
258 void	 bpfattach(struct ifnet *, u_int, u_int);
259 void	 bpfattach2(struct ifnet *, u_int, u_int, void *);
260 void	 bpfdetach(struct ifnet *);
261 void	 bpf_change_type(struct ifnet *, u_int, u_int);
262 void	 bpfilterattach(int);
263 #endif
264 
265 u_int	 bpf_filter(struct bpf_insn *, u_char *, u_int, u_int);
266 
267 /*
268  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
269  */
270 #define BPF_MEMWORDS 16
271 
272 #endif /* _NET_BPF_H_ */
273