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bpf.h revision 1.29
      1 /*	$NetBSD: bpf.h,v 1.29 2001/12/14 23:30:02 thorpej 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. All advertising materials mentioning features or use of this software
     21  *    must display the following acknowledgement:
     22  *	This product includes software developed by the University of
     23  *	California, Berkeley and its contributors.
     24  * 4. Neither the name of the University nor the names of its contributors
     25  *    may be used to endorse or promote products derived from this software
     26  *    without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38  * SUCH DAMAGE.
     39  *
     40  *	@(#)bpf.h	8.2 (Berkeley) 1/9/95
     41  * @(#) Header: bpf.h,v 1.36 97/06/12 14:29:53 leres Exp  (LBL)
     42  */
     43 
     44 #ifndef _NET_BPF_H_
     45 #define _NET_BPF_H_
     46 
     47 #include <sys/time.h>
     48 
     49 /* BSD style release date */
     50 #define BPF_RELEASE 199606
     51 
     52 typedef	int bpf_int32;
     53 typedef	u_int bpf_u_int32;
     54 
     55 /*
     56  * Alignment macros.  BPF_WORDALIGN rounds up to the next
     57  * even multiple of BPF_ALIGNMENT.
     58  */
     59 #define BPF_ALIGNMENT sizeof(long)
     60 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
     61 
     62 #define BPF_MAXINSNS 512
     63 #define BPF_MAXBUFSIZE 0x8000
     64 #define BPF_MINBUFSIZE 32
     65 
     66 /*
     67  *  Structure for BIOCSETF.
     68  */
     69 struct bpf_program {
     70 	u_int bf_len;
     71 	struct bpf_insn *bf_insns;
     72 };
     73 
     74 /*
     75  * Struct returned by BIOCGSTATS.
     76  */
     77 struct bpf_stat {
     78 	u_int bs_recv;		/* number of packets received */
     79 	u_int bs_drop;		/* number of packets dropped */
     80 };
     81 
     82 /*
     83  * Struct return by BIOCVERSION.  This represents the version number of
     84  * the filter language described by the instruction encodings below.
     85  * bpf understands a program iff kernel_major == filter_major &&
     86  * kernel_minor >= filter_minor, that is, if the value returned by the
     87  * running kernel has the same major number and a minor number equal
     88  * equal to or less than the filter being downloaded.  Otherwise, the
     89  * results are undefined, meaning an error may be returned or packets
     90  * may be accepted haphazardly.
     91  * It has nothing to do with the source code version.
     92  */
     93 struct bpf_version {
     94 	u_short bv_major;
     95 	u_short bv_minor;
     96 };
     97 /* Current version number of filter architecture. */
     98 #define BPF_MAJOR_VERSION 1
     99 #define BPF_MINOR_VERSION 1
    100 
    101 /*
    102  * BPF ioctls
    103  *
    104  * The first set is for compatibility with Sun's pcc style
    105  * header files.  If your using gcc, we assume that you
    106  * have run fixincludes so the latter set should work.
    107  */
    108 #if (defined(sun) || defined(ibm032)) && !defined(__GNUC__)
    109 #define	BIOCGBLEN	_IOR(B,102, u_int)
    110 #define	BIOCSBLEN	_IOWR(B,102, u_int)
    111 #define	BIOCSETF	_IOW(B,103, struct bpf_program)
    112 #define	BIOCFLUSH	_IO(B,104)
    113 #define BIOCPROMISC	_IO(B,105)
    114 #define	BIOCGDLT	_IOR(B,106, u_int)
    115 #define BIOCGETIF	_IOR(B,107, struct ifreq)
    116 #define BIOCSETIF	_IOW(B,108, struct ifreq)
    117 #define BIOCSRTIMEOUT	_IOW(B,109, struct timeval)
    118 #define BIOCGRTIMEOUT	_IOR(B,110, struct timeval)
    119 #define BIOCGSTATS	_IOR(B,111, struct bpf_stat)
    120 #define BIOCIMMEDIATE	_IOW(B,112, u_int)
    121 #define BIOCVERSION	_IOR(B,113, struct bpf_version)
    122 #define BIOCSTCPF	_IOW(B,114, struct bpf_program)
    123 #define BIOCSUDPF	_IOW(B,115, struct bpf_program)
    124 #define	BIOCGHDRCMPLT	_IOR(B,116, u_int)
    125 #define	BIOCSHDRCMPLT	_IOW(B,117, u_int)
    126 #else
    127 #define	BIOCGBLEN	_IOR('B',102, u_int)
    128 #define	BIOCSBLEN	_IOWR('B',102, u_int)
    129 #define	BIOCSETF	_IOW('B',103, struct bpf_program)
    130 #define	BIOCFLUSH	_IO('B',104)
    131 #define BIOCPROMISC	_IO('B',105)
    132 #define	BIOCGDLT	_IOR('B',106, u_int)
    133 #define BIOCGETIF	_IOR('B',107, struct ifreq)
    134 #define BIOCSETIF	_IOW('B',108, struct ifreq)
    135 #define BIOCSRTIMEOUT	_IOW('B',109, struct timeval)
    136 #define BIOCGRTIMEOUT	_IOR('B',110, struct timeval)
    137 #define BIOCGSTATS	_IOR('B',111, struct bpf_stat)
    138 #define BIOCIMMEDIATE	_IOW('B',112, u_int)
    139 #define BIOCVERSION	_IOR('B',113, struct bpf_version)
    140 #define BIOCSTCPF	_IOW('B',114, struct bpf_program)
    141 #define BIOCSUDPF	_IOW('B',115, struct bpf_program)
    142 #define	BIOCGHDRCMPLT	_IOR('B',116, u_int)
    143 #define	BIOCSHDRCMPLT	_IOW('B',117, u_int)
    144 #endif
    145 
    146 /*
    147  * Structure prepended to each packet.
    148  */
    149 struct bpf_hdr {
    150 	struct timeval	bh_tstamp;	/* time stamp */
    151 	u_int32_t	bh_caplen;	/* length of captured portion */
    152 	u_int32_t	bh_datalen;	/* original length of packet */
    153 	u_int16_t	bh_hdrlen;	/* length of bpf header (this struct
    154 					   plus alignment padding) */
    155 };
    156 /*
    157  * Because the structure above is not a multiple of 4 bytes, some compilers
    158  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
    159  * Only the kernel needs to know about it; applications use bh_hdrlen.
    160  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
    161  * XXX padding by using the size of the header data elements.  This is
    162  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
    163  */
    164 #ifdef _KERNEL
    165 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
    166     defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
    167     defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
    168 #define SIZEOF_BPF_HDR 18
    169 #else
    170 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
    171 #endif
    172 #endif
    173 
    174 /* Pull in data-link level type codes. */
    175 #include <net/dlt.h>
    176 
    177 /*
    178  * The instruction encondings.
    179  */
    180 /* instruction classes */
    181 #define BPF_CLASS(code) ((code) & 0x07)
    182 #define		BPF_LD		0x00
    183 #define		BPF_LDX		0x01
    184 #define		BPF_ST		0x02
    185 #define		BPF_STX		0x03
    186 #define		BPF_ALU		0x04
    187 #define		BPF_JMP		0x05
    188 #define		BPF_RET		0x06
    189 #define		BPF_MISC	0x07
    190 
    191 /* ld/ldx fields */
    192 #define BPF_SIZE(code)	((code) & 0x18)
    193 #define		BPF_W		0x00
    194 #define		BPF_H		0x08
    195 #define		BPF_B		0x10
    196 #define BPF_MODE(code)	((code) & 0xe0)
    197 #define		BPF_IMM 	0x00
    198 #define		BPF_ABS		0x20
    199 #define		BPF_IND		0x40
    200 #define		BPF_MEM		0x60
    201 #define		BPF_LEN		0x80
    202 #define		BPF_MSH		0xa0
    203 
    204 /* alu/jmp fields */
    205 #define BPF_OP(code)	((code) & 0xf0)
    206 #define		BPF_ADD		0x00
    207 #define		BPF_SUB		0x10
    208 #define		BPF_MUL		0x20
    209 #define		BPF_DIV		0x30
    210 #define		BPF_OR		0x40
    211 #define		BPF_AND		0x50
    212 #define		BPF_LSH		0x60
    213 #define		BPF_RSH		0x70
    214 #define		BPF_NEG		0x80
    215 #define		BPF_JA		0x00
    216 #define		BPF_JEQ		0x10
    217 #define		BPF_JGT		0x20
    218 #define		BPF_JGE		0x30
    219 #define		BPF_JSET	0x40
    220 #define BPF_SRC(code)	((code) & 0x08)
    221 #define		BPF_K		0x00
    222 #define		BPF_X		0x08
    223 
    224 /* ret - BPF_K and BPF_X also apply */
    225 #define BPF_RVAL(code)	((code) & 0x18)
    226 #define		BPF_A		0x10
    227 
    228 /* misc */
    229 #define BPF_MISCOP(code) ((code) & 0xf8)
    230 #define		BPF_TAX		0x00
    231 #define		BPF_TXA		0x80
    232 
    233 /*
    234  * The instruction data structure.
    235  */
    236 struct bpf_insn {
    237 	u_int16_t code;
    238 	u_char 	  jt;
    239 	u_char 	  jf;
    240 	int32_t	  k;
    241 };
    242 
    243 /*
    244  * Macros for insn array initializers.
    245  */
    246 #define BPF_STMT(code, k) { (u_int16_t)(code), 0, 0, k }
    247 #define BPF_JUMP(code, k, jt, jf) { (u_int16_t)(code), jt, jf, k }
    248 
    249 #ifdef _KERNEL
    250 int	 bpf_validate __P((struct bpf_insn *, int));
    251 void	 bpf_tap __P((caddr_t, u_char *, u_int));
    252 void	 bpf_mtap __P((caddr_t, struct mbuf *));
    253 void	 bpfattach __P((struct ifnet *, u_int, u_int));
    254 void	 bpfdetach __P((struct ifnet *));
    255 void	 bpf_change_type __P((struct ifnet *, u_int, u_int));
    256 void	 bpfilterattach __P((int));
    257 #endif
    258 
    259 u_int	 bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int));
    260 
    261 /*
    262  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
    263  */
    264 #define BPF_MEMWORDS 16
    265 
    266 #endif /* _NET_BPF_H_ */
    267