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bpf.h revision 1.38
      1 /*	$NetBSD: bpf.h,v 1.38 2004/05/29 08:56:19 darrenr 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 #define BIOCMMAPINFO	_IOWR('B',122, struct bpf_mmapinfo)
    138 
    139 /*
    140  * Structure prepended to each packet.
    141  */
    142 struct bpf_hdr {
    143 	struct timeval	bh_tstamp;	/* time stamp */
    144 	u_int32_t	bh_caplen;	/* length of captured portion */
    145 	u_int32_t	bh_datalen;	/* original length of packet */
    146 	u_int16_t	bh_hdrlen;	/* length of bpf header (this struct
    147 					   plus alignment padding) */
    148 };
    149 /*
    150  * Because the structure above is not a multiple of 4 bytes, some compilers
    151  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
    152  * Only the kernel needs to know about it; applications use bh_hdrlen.
    153  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
    154  * XXX padding by using the size of the header data elements.  This is
    155  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
    156  */
    157 #ifdef _KERNEL
    158 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
    159     defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
    160     defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
    161 #define SIZEOF_BPF_HDR 18
    162 #else
    163 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
    164 #endif
    165 #endif
    166 
    167 /* Pull in data-link level type codes. */
    168 #include <net/dlt.h>
    169 
    170 /*
    171  * The instruction encondings.
    172  */
    173 /* instruction classes */
    174 #define BPF_CLASS(code) ((code) & 0x07)
    175 #define		BPF_LD		0x00
    176 #define		BPF_LDX		0x01
    177 #define		BPF_ST		0x02
    178 #define		BPF_STX		0x03
    179 #define		BPF_ALU		0x04
    180 #define		BPF_JMP		0x05
    181 #define		BPF_RET		0x06
    182 #define		BPF_MISC	0x07
    183 
    184 /* ld/ldx fields */
    185 #define BPF_SIZE(code)	((code) & 0x18)
    186 #define		BPF_W		0x00
    187 #define		BPF_H		0x08
    188 #define		BPF_B		0x10
    189 #define BPF_MODE(code)	((code) & 0xe0)
    190 #define		BPF_IMM 	0x00
    191 #define		BPF_ABS		0x20
    192 #define		BPF_IND		0x40
    193 #define		BPF_MEM		0x60
    194 #define		BPF_LEN		0x80
    195 #define		BPF_MSH		0xa0
    196 
    197 /* alu/jmp fields */
    198 #define BPF_OP(code)	((code) & 0xf0)
    199 #define		BPF_ADD		0x00
    200 #define		BPF_SUB		0x10
    201 #define		BPF_MUL		0x20
    202 #define		BPF_DIV		0x30
    203 #define		BPF_OR		0x40
    204 #define		BPF_AND		0x50
    205 #define		BPF_LSH		0x60
    206 #define		BPF_RSH		0x70
    207 #define		BPF_NEG		0x80
    208 #define		BPF_JA		0x00
    209 #define		BPF_JEQ		0x10
    210 #define		BPF_JGT		0x20
    211 #define		BPF_JGE		0x30
    212 #define		BPF_JSET	0x40
    213 #define BPF_SRC(code)	((code) & 0x08)
    214 #define		BPF_K		0x00
    215 #define		BPF_X		0x08
    216 
    217 /* ret - BPF_K and BPF_X also apply */
    218 #define BPF_RVAL(code)	((code) & 0x18)
    219 #define		BPF_A		0x10
    220 
    221 /* misc */
    222 #define BPF_MISCOP(code) ((code) & 0xf8)
    223 #define		BPF_TAX		0x00
    224 #define		BPF_TXA		0x80
    225 
    226 /*
    227  * The instruction data structure.
    228  */
    229 struct bpf_insn {
    230 	u_int16_t code;
    231 	u_char 	  jt;
    232 	u_char 	  jf;
    233 	int32_t	  k;
    234 };
    235 
    236 /*
    237  * Macros for insn array initializers.
    238  */
    239 #define BPF_STMT(code, k) { (u_int16_t)(code), 0, 0, k }
    240 #define BPF_JUMP(code, k, jt, jf) { (u_int16_t)(code), jt, jf, k }
    241 
    242 /*
    243  * Structure to retrieve available DLTs for the interface.
    244  */
    245 struct bpf_dltlist {
    246 	u_int	bfl_len;	/* number of bfd_list array */
    247 	u_int	*bfl_list;	/* array of DLTs */
    248 };
    249 
    250 /*
    251  * Structure to pass information for use with mmap'd regions
    252  */
    253 typedef enum bpf_mmapops {
    254 	BPM_RELEASE = 0,
    255 	BPM_ACQUIRE
    256 } bpf_mmapops_t;
    257 
    258 struct bpf_mmapinfo {
    259 	bpf_mmapops_t	bpm_op;		/* operation to perform */
    260 	int		bpm_which;	/* which buffer is ready */
    261 	int		bpm_len;	/* # of bytes ready to process */
    262 };
    263 
    264 #ifdef _KERNEL
    265 int	 bpf_validate __P((struct bpf_insn *, int));
    266 void	 bpf_tap __P((caddr_t, u_char *, u_int));
    267 void	 bpf_mtap __P((caddr_t, struct mbuf *));
    268 void	 bpf_mtap2 __P((caddr_t, void *, u_int, struct mbuf *));
    269 void	 bpfattach __P((struct ifnet *, u_int, u_int));
    270 void	 bpfattach2 __P((struct ifnet *, u_int, u_int, caddr_t *));
    271 void	 bpfdetach __P((struct ifnet *));
    272 void	 bpf_change_type __P((struct ifnet *, u_int, u_int));
    273 void	 bpfilterattach __P((int));
    274 #endif
    275 
    276 u_int	 bpf_filter __P((struct bpf_insn *, u_char *, u_int, u_int));
    277 
    278 /*
    279  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
    280  */
    281 #define BPF_MEMWORDS 16
    282 
    283 #endif /* _NET_BPF_H_ */
    284