sys/net/bpf.h

   1 /*      $NetBSD: bpf.h,v 1.49 2009/01/11 02:45:54 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 and net.bpf.stats sysctl.
  73  */
  74 struct bpf_stat {
  75         uint64_t bs_recv;       /* number of packets received */
  76         uint64_t bs_drop;       /* number of packets dropped */
  77         uint64_t bs_capt;       /* number of packets captured */
  78         uint64_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 #ifdef COMPAT_50
 124 #include <compat/sys/time.h>
 125 #define BIOCSORTIMEOUT   _IOW('B',109, struct timeval50)
 126 #define BIOCGORTIMEOUT   _IOR('B',110, struct timeval50)
 127 #endif
 128 #define BIOCGSTATS       _IOR('B',111, struct bpf_stat)
 129 #define BIOCGSTATSOLD    _IOR('B',111, struct bpf_stat_old)
 130 #define BIOCIMMEDIATE    _IOW('B',112, u_int)
 131 #define BIOCVERSION      _IOR('B',113, struct bpf_version)
 132 #define BIOCSTCPF        _IOW('B',114, struct bpf_program)
 133 #define BIOCSUDPF        _IOW('B',115, struct bpf_program)
 134 #define BIOCGHDRCMPLT    _IOR('B',116, u_int)
 135 #define BIOCSHDRCMPLT    _IOW('B',117, u_int)
 136 #define BIOCSDLT         _IOW('B',118, u_int)
 137 #define BIOCGDLTLIST    _IOWR('B',119, struct bpf_dltlist)
 138 #define BIOCGSEESENT     _IOR('B',120, u_int)
 139 #define BIOCSSEESENT     _IOW('B',121, u_int)
 140 #define BIOCSRTIMEOUT    _IOW('B',122, struct timeval)
 141 #define BIOCGRTIMEOUT    _IOR('B',123, struct timeval)
 142
 143 /*
 144  * Structure prepended to each packet. This is "wire" format, so we
 145  * cannot change it unfortunately to 64 bit times on 32 bit systems [yet].
 146  */
 147 struct bpf_timeval {
 148         long tv_sec;
 149         long tv_usec;
 150 };
 151
 152 struct bpf_hdr {
 153         struct bpf_timeval bh_tstamp;   /* time stamp */
 154         uint32_t        bh_caplen;      /* length of captured portion */
 155         uint32_t        bh_datalen;     /* original length of packet */
 156         uint16_t        bh_hdrlen;      /* length of bpf header (this struct
 157                                            plus alignment padding) */
 158 };
 159 /*
 160  * Because the structure above is not a multiple of 4 bytes, some compilers
 161  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
 162  * Only the kernel needs to know about it; applications use bh_hdrlen.
 163  * XXX To save a few bytes on 32-bit machines, we avoid end-of-struct
 164  * XXX padding by using the size of the header data elements.  This is
 165  * XXX fail-safe: on new machines, we just use the 'safe' sizeof.
 166  */
 167 #ifdef _KERNEL
 168 #if defined(__arm32__) || defined(__i386__) || defined(__m68k__) || \
 169     defined(__mips__) || defined(__ns32k__) || defined(__vax__) || \
 170     defined(__sh__) || (defined(__sparc__) && !defined(__sparc64__))
 171 #define SIZEOF_BPF_HDR 18
 172 #else
 173 #define SIZEOF_BPF_HDR sizeof(struct bpf_hdr)
 174 #endif
 175 #endif
 176
 177 /* Pull in data-link level type codes. */
 178 #include <net/dlt.h>
 179
 180 /*
 181  * The instruction encodings.
 182  */
 183 /* instruction classes */
 184 #define BPF_CLASS(code) ((code) & 0x07)
 185 #define         BPF_LD          0x00
 186 #define         BPF_LDX         0x01
 187 #define         BPF_ST          0x02
 188 #define         BPF_STX         0x03
 189 #define         BPF_ALU         0x04
 190 #define         BPF_JMP         0x05
 191 #define         BPF_RET         0x06
 192 #define         BPF_MISC        0x07
 193
 194 /* ld/ldx fields */
 195 #define BPF_SIZE(code)  ((code) & 0x18)
 196 #define         BPF_W           0x00
 197 #define         BPF_H           0x08
 198 #define         BPF_B           0x10
 199 #define BPF_MODE(code)  ((code) & 0xe0)
 200 #define         BPF_IMM         0x00
 201 #define         BPF_ABS         0x20
 202 #define         BPF_IND         0x40
 203 #define         BPF_MEM         0x60
 204 #define         BPF_LEN         0x80
 205 #define         BPF_MSH         0xa0
 206
 207 /* alu/jmp fields */
 208 #define BPF_OP(code)    ((code) & 0xf0)
 209 #define         BPF_ADD         0x00
 210 #define         BPF_SUB         0x10
 211 #define         BPF_MUL         0x20
 212 #define         BPF_DIV         0x30
 213 #define         BPF_OR          0x40
 214 #define         BPF_AND         0x50
 215 #define         BPF_LSH         0x60
 216 #define         BPF_RSH         0x70
 217 #define         BPF_NEG         0x80
 218 #define         BPF_JA          0x00
 219 #define         BPF_JEQ         0x10
 220 #define         BPF_JGT         0x20
 221 #define         BPF_JGE         0x30
 222 #define         BPF_JSET        0x40
 223 #define BPF_SRC(code)   ((code) & 0x08)
 224 #define         BPF_K           0x00
 225 #define         BPF_X           0x08
 226
 227 /* ret - BPF_K and BPF_X also apply */
 228 #define BPF_RVAL(code)  ((code) & 0x18)
 229 #define         BPF_A           0x10
 230
 231 /* misc */
 232 #define BPF_MISCOP(code) ((code) & 0xf8)
 233 #define         BPF_TAX         0x00
 234 #define         BPF_TXA         0x80
 235
 236 /*
 237  * The instruction data structure.
 238  */
 239 struct bpf_insn {
 240         uint16_t  code;
 241         u_char    jt;
 242         u_char    jf;
 243         uint32_t  k;
 244 };
 245
 246 /*
 247  * Macros for insn array initializers.
 248  */
 249 #define BPF_STMT(code, k) { (uint16_t)(code), 0, 0, k }
 250 #define BPF_JUMP(code, k, jt, jf) { (uint16_t)(code), jt, jf, k }
 251
 252 /*
 253  * Structure to retrieve available DLTs for the interface.
 254  */
 255 struct bpf_dltlist {
 256         u_int   bfl_len;        /* number of bfd_list array */
 257         u_int   *bfl_list;      /* array of DLTs */
 258 };
 259
 260 #ifdef _KERNEL
 261 int      bpf_validate(struct bpf_insn *, int);
 262 void     bpf_tap(void *, u_char *, u_int);
 263 void     bpf_mtap(void *, struct mbuf *);
 264 void     bpf_mtap2(void *, void *, u_int, struct mbuf *);
 265 void     bpf_mtap_af(void *, uint32_t, struct mbuf *);
 266 void     bpf_mtap_et(void *, uint16_t, struct mbuf *);
 267 void     bpf_mtap_sl_in(void *, u_char *, struct mbuf **);
 268 void     bpf_mtap_sl_out(void *, u_char *, struct mbuf *);
 269 void     bpfattach(struct ifnet *, u_int, u_int);
 270 void     bpfattach2(struct ifnet *, u_int, u_int, void *);
 271 void     bpfdetach(struct ifnet *);
 272 void     bpf_change_type(struct ifnet *, u_int, u_int);
 273 void     bpfilterattach(int);
 274 #endif
 275
 276 u_int    bpf_filter(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_ */