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bpf.h revision 1.58.2.2
      1 /*	$NetBSD: bpf.h,v 1.58.2.2 2014/05/22 11:41:08 yamt 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 __BEGIN_DECLS
     49 
     50 typedef	int bpf_int32;
     51 typedef	u_int bpf_u_int32;
     52 
     53 /*
     54  * Alignment macros.  BPF_WORDALIGN rounds up to the next
     55  * even multiple of BPF_ALIGNMENT.
     56  */
     57 #define BPF_ALIGNMENT sizeof(long)
     58 #define BPF_ALIGNMENT32 sizeof(int)
     59 
     60 #define BPF_WORDALIGN(x) (((x)+(BPF_ALIGNMENT-1))&~(BPF_ALIGNMENT-1))
     61 #define BPF_WORDALIGN32(x) (((x)+(BPF_ALIGNMENT32-1))&~(BPF_ALIGNMENT32-1))
     62 
     63 #define BPF_MAXINSNS 512
     64 #define BPF_DFLTBUFSIZE (1024*1024)	/* default static upper limit */
     65 #define BPF_MAXBUFSIZE (1024*1024*16)	/* hard limit on sysctl'able value */
     66 #define BPF_MINBUFSIZE 32
     67 
     68 /*
     69  *  Structure for BIOCSETF.
     70  */
     71 struct bpf_program {
     72 	u_int bf_len;
     73 	struct bpf_insn *bf_insns;
     74 };
     75 
     76 /*
     77  * Struct returned by BIOCGSTATS and net.bpf.stats sysctl.
     78  */
     79 struct bpf_stat {
     80 	uint64_t bs_recv;	/* number of packets received */
     81 	uint64_t bs_drop;	/* number of packets dropped */
     82 	uint64_t bs_capt;	/* number of packets captured */
     83 	uint64_t bs_padding[13];
     84 };
     85 
     86 /*
     87  * Struct returned by BIOCGSTATSOLD.
     88  */
     89 struct bpf_stat_old {
     90 	u_int bs_recv;		/* number of packets received */
     91 	u_int bs_drop;		/* number of packets dropped */
     92 };
     93 
     94 /*
     95  * Struct return by BIOCVERSION.  This represents the version number of
     96  * the filter language described by the instruction encodings below.
     97  * bpf understands a program iff kernel_major == filter_major &&
     98  * kernel_minor >= filter_minor, that is, if the value returned by the
     99  * running kernel has the same major number and a minor number equal
    100  * equal to or less than the filter being downloaded.  Otherwise, the
    101  * results are undefined, meaning an error may be returned or packets
    102  * may be accepted haphazardly.
    103  * It has nothing to do with the source code version.
    104  */
    105 struct bpf_version {
    106 	u_short bv_major;
    107 	u_short bv_minor;
    108 };
    109 /* Current version number of filter architecture. */
    110 #define BPF_MAJOR_VERSION 1
    111 #define BPF_MINOR_VERSION 1
    112 
    113 /*
    114  * BPF ioctls
    115  *
    116  * The first set is for compatibility with Sun's pcc style
    117  * header files.  If your using gcc, we assume that you
    118  * have run fixincludes so the latter set should work.
    119  */
    120 #define BIOCGBLEN	 _IOR('B',102, u_int)
    121 #define BIOCSBLEN	_IOWR('B',102, u_int)
    122 #define BIOCSETF	 _IOW('B',103, struct bpf_program)
    123 #define BIOCFLUSH	  _IO('B',104)
    124 #define BIOCPROMISC	  _IO('B',105)
    125 #define BIOCGDLT	 _IOR('B',106, u_int)
    126 #define BIOCGETIF	 _IOR('B',107, struct ifreq)
    127 #define BIOCSETIF	 _IOW('B',108, struct ifreq)
    128 #ifdef COMPAT_50
    129 #include <compat/sys/time.h>
    130 #define BIOCSORTIMEOUT	 _IOW('B',109, struct timeval50)
    131 #define BIOCGORTIMEOUT	 _IOR('B',110, struct timeval50)
    132 #endif
    133 #define BIOCGSTATS	 _IOR('B',111, struct bpf_stat)
    134 #define BIOCGSTATSOLD	 _IOR('B',111, struct bpf_stat_old)
    135 #define BIOCIMMEDIATE	 _IOW('B',112, u_int)
    136 #define BIOCVERSION	 _IOR('B',113, struct bpf_version)
    137 #define BIOCSTCPF	 _IOW('B',114, struct bpf_program)
    138 #define BIOCSUDPF	 _IOW('B',115, struct bpf_program)
    139 #define BIOCGHDRCMPLT	 _IOR('B',116, u_int)
    140 #define BIOCSHDRCMPLT	 _IOW('B',117, u_int)
    141 #define BIOCSDLT	 _IOW('B',118, u_int)
    142 #define BIOCGDLTLIST	_IOWR('B',119, struct bpf_dltlist)
    143 #define BIOCGSEESENT	 _IOR('B',120, u_int)
    144 #define BIOCSSEESENT	 _IOW('B',121, u_int)
    145 #define BIOCSRTIMEOUT	 _IOW('B',122, struct timeval)
    146 #define BIOCGRTIMEOUT	 _IOR('B',123, struct timeval)
    147 #define BIOCGFEEDBACK	 _IOR('B',124, u_int)
    148 #define BIOCSFEEDBACK	 _IOW('B',125, u_int)
    149 #define BIOCFEEDBACK     BIOCSFEEDBACK		/* FreeBSD name */
    150 
    151 /*
    152  * Structure prepended to each packet. This is "wire" format, so we
    153  * cannot change it unfortunately to 64 bit times on 32 bit systems [yet].
    154  */
    155 struct bpf_timeval {
    156 	long tv_sec;
    157 	long tv_usec;
    158 };
    159 
    160 struct bpf_timeval32 {
    161 	int32_t tv_sec;
    162 	int32_t tv_usec;
    163 };
    164 
    165 struct bpf_hdr {
    166 	struct bpf_timeval bh_tstamp;	/* time stamp */
    167 	uint32_t	bh_caplen;	/* length of captured portion */
    168 	uint32_t	bh_datalen;	/* original length of packet */
    169 	uint16_t	bh_hdrlen;	/* length of bpf header (this struct
    170 					   plus alignment padding) */
    171 };
    172 
    173 struct bpf_hdr32 {
    174 	struct bpf_timeval32 bh_tstamp;	/* time stamp */
    175 	uint32_t	bh_caplen;	/* length of captured portion */
    176 	uint32_t	bh_datalen;	/* original length of packet */
    177 	uint16_t	bh_hdrlen;	/* length of bpf header (this struct
    178 					   plus alignment padding) */
    179 };
    180 /*
    181  * Because the structure above is not a multiple of 4 bytes, some compilers
    182  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
    183  * Only the kernel needs to know about it; applications use bh_hdrlen.
    184  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
    185  * XXX padding by using the size of the header data elements.  This is
    186  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
    187  */
    188 #ifdef _KERNEL
    189 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
    190     defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
    191     defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
    192 #define SIZEOF_BPF_HDR 18
    193 #define SIZEOF_BPF_HDR32 18
    194 #else
    195 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
    196 #define SIZEOF_BPF_HDR32 sizeof(struct bpf_hdr32)
    197 #endif
    198 #endif
    199 
    200 /* Pull in data-link level type codes. */
    201 #include <net/dlt.h>
    202 
    203 /*
    204  * The instruction encodings.
    205  */
    206 /* instruction classes */
    207 #define BPF_CLASS(code) ((code) & 0x07)
    208 #define		BPF_LD		0x00
    209 #define		BPF_LDX		0x01
    210 #define		BPF_ST		0x02
    211 #define		BPF_STX		0x03
    212 #define		BPF_ALU		0x04
    213 #define		BPF_JMP		0x05
    214 #define		BPF_RET		0x06
    215 #define		BPF_MISC	0x07
    216 
    217 /* ld/ldx fields */
    218 #define BPF_SIZE(code)	((code) & 0x18)
    219 #define		BPF_W		0x00
    220 #define		BPF_H		0x08
    221 #define		BPF_B		0x10
    222 #define BPF_MODE(code)	((code) & 0xe0)
    223 #define		BPF_IMM 	0x00
    224 #define		BPF_ABS		0x20
    225 #define		BPF_IND		0x40
    226 #define		BPF_MEM		0x60
    227 #define		BPF_LEN		0x80
    228 #define		BPF_MSH		0xa0
    229 
    230 /* alu/jmp fields */
    231 #define BPF_OP(code)	((code) & 0xf0)
    232 #define		BPF_ADD		0x00
    233 #define		BPF_SUB		0x10
    234 #define		BPF_MUL		0x20
    235 #define		BPF_DIV		0x30
    236 #define		BPF_OR		0x40
    237 #define		BPF_AND		0x50
    238 #define		BPF_LSH		0x60
    239 #define		BPF_RSH		0x70
    240 #define		BPF_NEG		0x80
    241 #define		BPF_JA		0x00
    242 #define		BPF_JEQ		0x10
    243 #define		BPF_JGT		0x20
    244 #define		BPF_JGE		0x30
    245 #define		BPF_JSET	0x40
    246 #define BPF_SRC(code)	((code) & 0x08)
    247 #define		BPF_K		0x00
    248 #define		BPF_X		0x08
    249 
    250 /* ret - BPF_K and BPF_X also apply */
    251 #define BPF_RVAL(code)	((code) & 0x18)
    252 #define		BPF_A		0x10
    253 
    254 /* misc */
    255 #define BPF_MISCOP(code) ((code) & 0xf8)
    256 #define		BPF_TAX		0x00
    257 #define		BPF_COP		0x20
    258 #define		BPF_COPX	0x40
    259 #define		BPF_TXA		0x80
    260 
    261 /*
    262  * The instruction data structure.
    263  */
    264 struct bpf_insn {
    265 	uint16_t  code;
    266 	u_char 	  jt;
    267 	u_char 	  jf;
    268 	uint32_t  k;
    269 };
    270 
    271 /*
    272  * Macros for insn array initializers.
    273  */
    274 #define BPF_STMT(code, k) { (uint16_t)(code), 0, 0, k }
    275 #define BPF_JUMP(code, k, jt, jf) { (uint16_t)(code), jt, jf, k }
    276 
    277 /*
    278  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
    279  */
    280 #define	BPF_MEMWORDS	16
    281 
    282 /*
    283  * Structure to retrieve available DLTs for the interface.
    284  */
    285 struct bpf_dltlist {
    286 	u_int	bfl_len;	/* number of bfd_list array */
    287 	u_int	*bfl_list;	/* array of DLTs */
    288 };
    289 
    290 struct bpf_ctx;
    291 typedef struct bpf_ctx bpf_ctx_t;
    292 
    293 struct bpf_args;
    294 typedef struct bpf_args bpf_args_t;
    295 
    296 #if defined(_KERNEL) || defined(__BPF_PRIVATE)
    297 typedef uint32_t (*bpf_copfunc_t)(bpf_ctx_t *, bpf_args_t *, uint32_t);
    298 
    299 struct bpf_args {
    300 	const struct mbuf *	pkt;
    301 	size_t			wirelen;
    302 	size_t			buflen;
    303 	uint32_t		mem[BPF_MEMWORDS];
    304 	void *			arg;
    305 };
    306 
    307 struct bpf_ctx {
    308 	const bpf_copfunc_t *	copfuncs;
    309 	size_t			nfuncs;
    310 };
    311 #endif
    312 
    313 #ifdef _KERNEL
    314 #include <net/bpfjit.h>
    315 #include <net/if.h>
    316 
    317 struct bpf_if;
    318 
    319 struct bpf_ops {
    320 	void (*bpf_attach)(struct ifnet *, u_int, u_int, struct bpf_if **);
    321 	void (*bpf_detach)(struct ifnet *);
    322 	void (*bpf_change_type)(struct ifnet *, u_int, u_int);
    323 
    324 	void (*bpf_tap)(struct bpf_if *, u_char *, u_int);
    325 	void (*bpf_mtap)(struct bpf_if *, struct mbuf *);
    326 	void (*bpf_mtap2)(struct bpf_if *, void *, u_int, struct mbuf *);
    327 	void (*bpf_mtap_af)(struct bpf_if *, uint32_t, struct mbuf *);
    328 	void (*bpf_mtap_sl_in)(struct bpf_if *, u_char *, struct mbuf **);
    329 	void (*bpf_mtap_sl_out)(struct bpf_if *, u_char *, struct mbuf *);
    330 };
    331 
    332 extern struct bpf_ops *bpf_ops;
    333 
    334 static inline void
    335 bpf_attach(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
    336 {
    337 	bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, &_ifp->if_bpf);
    338 }
    339 
    340 static inline void
    341 bpf_attach2(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen, struct bpf_if **_dp)
    342 {
    343 	bpf_ops->bpf_attach(_ifp, _dlt, _hdrlen, _dp);
    344 }
    345 
    346 static inline void
    347 bpf_tap(struct ifnet *_ifp, u_char *_pkt, u_int _len)
    348 {
    349 	if (_ifp->if_bpf)
    350 		bpf_ops->bpf_tap(_ifp->if_bpf, _pkt, _len);
    351 }
    352 
    353 static inline void
    354 bpf_mtap(struct ifnet *_ifp, struct mbuf *_m)
    355 {
    356 	if (_ifp->if_bpf)
    357 		bpf_ops->bpf_mtap(_ifp->if_bpf, _m);
    358 }
    359 
    360 static inline void
    361 bpf_mtap2(struct bpf_if *_bpf, void *_data, u_int _dlen, struct mbuf *_m)
    362 {
    363 	bpf_ops->bpf_mtap2(_bpf, _data, _dlen, _m);
    364 }
    365 
    366 static inline void
    367 bpf_mtap3(struct bpf_if *_bpf, struct mbuf *_m)
    368 {
    369 	if (_bpf)
    370 		bpf_ops->bpf_mtap(_bpf, _m);
    371 }
    372 
    373 static inline void
    374 bpf_mtap_af(struct ifnet *_ifp, uint32_t _af, struct mbuf *_m)
    375 {
    376 	if (_ifp->if_bpf)
    377 		bpf_ops->bpf_mtap_af(_ifp->if_bpf, _af, _m);
    378 }
    379 
    380 static inline void
    381 bpf_change_type(struct ifnet *_ifp, u_int _dlt, u_int _hdrlen)
    382 {
    383 	bpf_ops->bpf_change_type(_ifp, _dlt, _hdrlen);
    384 }
    385 
    386 static inline void
    387 bpf_detach(struct ifnet *_ifp)
    388 {
    389 	bpf_ops->bpf_detach(_ifp);
    390 }
    391 
    392 static inline void
    393 bpf_mtap_sl_in(struct ifnet *_ifp, u_char *_hdr, struct mbuf **_m)
    394 {
    395 	bpf_ops->bpf_mtap_sl_in(_ifp->if_bpf, _hdr, _m);
    396 }
    397 
    398 static inline void
    399 bpf_mtap_sl_out(struct ifnet *_ifp, u_char *_hdr, struct mbuf *_m)
    400 {
    401 	if (_ifp->if_bpf)
    402 		bpf_ops->bpf_mtap_sl_out(_ifp->if_bpf, _hdr, _m);
    403 }
    404 
    405 
    406 void     bpf_setops(void);
    407 
    408 void     bpf_ops_handover_enter(struct bpf_ops *);
    409 void     bpf_ops_handover_exit(void);
    410 
    411 void	 bpfilterattach(int);
    412 
    413 bpf_ctx_t *bpf_create(void);
    414 bpf_ctx_t *bpf_default_ctx(void);
    415 void	bpf_destroy(bpf_ctx_t *);
    416 
    417 int	bpf_set_cop(bpf_ctx_t *, const bpf_copfunc_t *, size_t);
    418 u_int	bpf_filter_ext(bpf_ctx_t *, const struct bpf_insn *, bpf_args_t *);
    419 int	bpf_validate_ext(bpf_ctx_t *, const struct bpf_insn *, int);
    420 
    421 bpfjit_func_t bpf_jit_generate(bpf_ctx_t *, void *, size_t);
    422 void	bpf_jit_freecode(bpfjit_func_t);
    423 
    424 #endif
    425 
    426 int	bpf_validate(const struct bpf_insn *, int);
    427 u_int	bpf_filter(const struct bpf_insn *, const u_char *, u_int, u_int);
    428 
    429 __END_DECLS
    430 
    431 #endif /* !_NET_BPF_H_ */
    432