sys/net/bpf.h

   1 /*
   2  * Copyright (c) 1990, 1991, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from the Stanford/CMU enet packet filter,
   6  * (net/enet.c) distributed as part of 4.3BSD, and code contributed
   7  * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence
   8  * Berkeley Laboratory.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  *      @(#)bpf.h       8.1 (Berkeley) 6/10/93
  35  *      @(#)bpf.h       1.34 (LBL)     6/16/96
  36  *
  37  * $FreeBSD: src/sys/net/bpf.h,v 1.21.2.4 2002/07/05 14:40:00 fenner Exp $
  38  */
  39
  40 #ifndef _NET_BPF_H_
  41 #define _NET_BPF_H_
  42
  43 #include <sys/param.h>
  44 #include <sys/time.h>
  45 #include <sys/ioccom.h>
  46
  47 __BEGIN_DECLS
  48
  49 #define BPF_MAX_CLONES  128
  50
  51 /* BSD style release date */
  52 #define BPF_RELEASE 199606
  53
  54 typedef int32_t   bpf_int32;
  55 typedef u_int32_t bpf_u_int32;
  56
  57 /*
  58  * Alignment macros.  BPF_WORDALIGN rounds up to the next
  59  * even multiple of BPF_ALIGNMENT.
  60  */
  61 #define BPF_ALIGNMENT sizeof(long)
  62 #define BPF_WORDALIGN(x) roundup2(x, BPF_ALIGNMENT)
  63
  64 #define BPF_MAXINSNS 512
  65 #define BPF_MAXBUFSIZE 0x80000
  66 #define BPF_DEFAULTBUFSIZE 4096
  67 #define BPF_MINBUFSIZE 32
  68
  69 /*
  70  *  Structure for BIOCSETF.
  71  */
  72 struct bpf_program {
  73         u_int bf_len;
  74         struct bpf_insn *bf_insns;
  75 };
  76
  77 /*
  78  * Struct returned by BIOCGSTATS.
  79  */
  80 struct bpf_stat {
  81         u_int bs_recv;          /* number of packets received */
  82         u_int bs_drop;          /* number of packets dropped */
  83 };
  84
  85 /*
  86  * Struct return by BIOCVERSION.  This represents the version number of
  87  * the filter language described by the instruction encodings below.
  88  * bpf understands a program iff kernel_major == filter_major &&
  89  * kernel_minor >= filter_minor, that is, if the value returned by the
  90  * running kernel has the same major number and a minor number equal
  91  * equal to or less than the filter being downloaded.  Otherwise, the
  92  * results are undefined, meaning an error may be returned or packets
  93  * may be accepted haphazardly.
  94  * It has nothing to do with the source code version.
  95  */
  96 struct bpf_version {
  97         u_short bv_major;
  98         u_short bv_minor;
  99 };
 100 /* Current version number of filter architecture. */
 101 #define BPF_MAJOR_VERSION 1
 102 #define BPF_MINOR_VERSION 1
 103
 104 #define BIOCGBLEN       _IOR('B',102, u_int)
 105 #define BIOCSBLEN       _IOWR('B',102, u_int)
 106 #define BIOCSETF        _IOW('B',103, struct bpf_program)
 107 #define BIOCFLUSH       _IO('B',104)
 108 #define BIOCPROMISC     _IO('B',105)
 109 #define BIOCGDLT        _IOR('B',106, u_int)
 110 #define BIOCGETIF       _IOR('B',107, struct ifreq)
 111 #define BIOCSETIF       _IOW('B',108, struct ifreq)
 112 #define BIOCSRTIMEOUT   _IOW('B',109, struct timeval)
 113 #define BIOCGRTIMEOUT   _IOR('B',110, struct timeval)
 114 #define BIOCGSTATS      _IOR('B',111, struct bpf_stat)
 115 #define BIOCIMMEDIATE   _IOW('B',112, u_int)
 116 #define BIOCVERSION     _IOR('B',113, struct bpf_version)
 117 #define BIOCGRSIG       _IOR('B',114, u_int)
 118 #define BIOCSRSIG       _IOW('B',115, u_int)
 119 #define BIOCGHDRCMPLT   _IOR('B',116, u_int)
 120 #define BIOCSHDRCMPLT   _IOW('B',117, u_int)
 121 #define BIOCGSEESENT    _IOR('B',118, u_int)
 122 #define BIOCSSEESENT    _IOW('B',119, u_int)
 123 #define BIOCSDLT        _IOW('B',120, u_int)
 124 #define BIOCGDLTLIST    _IOWR('B',121, struct bpf_dltlist)
 125 #define BIOCLOCK        _IO('B', 122)
 126 #define BIOCSETWF       _IOW('B',123, struct bpf_program)
 127 #define BIOCGFEEDBACK    _IOR('B',124, u_int)
 128 #define BIOCSFEEDBACK    _IOW('B',125, u_int)
 129 #define BIOCFEEDBACK     BIOCSFEEDBACK          /* FreeBSD name */
 130
 131 /*
 132  * Structure prepended to each packet.
 133  */
 134 struct bpf_hdr {
 135         struct timeval  bh_tstamp;      /* time stamp */
 136         bpf_u_int32     bh_caplen;      /* length of captured portion */
 137         bpf_u_int32     bh_datalen;     /* original length of packet */
 138         u_short         bh_hdrlen;      /* length of bpf header (this struct
 139                                            plus alignment padding) */
 140 };
 141 /*
 142  * Because the structure above is not a multiple of 4 bytes, some compilers
 143  * will insist on inserting padding; hence, sizeof(struct bpf_hdr) won't work.
 144  * Only the kernel needs to know about it; applications use bh_hdrlen.
 145  */
 146 #ifdef _KERNEL
 147 #define SIZEOF_BPF_HDR  (sizeof(struct bpf_hdr) <= 20 ? 18 : \
 148     sizeof(struct bpf_hdr))
 149 #endif
 150
 151 /* Pull in data-link level type codes. */
 152 #include <net/dlt.h>
 153
 154 /*
 155  * The instruction encodings.
 156  */
 157 /* instruction classes */
 158 #define BPF_CLASS(code) ((code) & 0x07)
 159 #define         BPF_LD          0x00
 160 #define         BPF_LDX         0x01
 161 #define         BPF_ST          0x02
 162 #define         BPF_STX         0x03
 163 #define         BPF_ALU         0x04
 164 #define         BPF_JMP         0x05
 165 #define         BPF_RET         0x06
 166 #define         BPF_MISC        0x07
 167
 168 /* ld/ldx fields */
 169 #define BPF_SIZE(code)  ((code) & 0x18)
 170 #define         BPF_W           0x00
 171 #define         BPF_H           0x08
 172 #define         BPF_B           0x10
 173 #define BPF_MODE(code)  ((code) & 0xe0)
 174 #define         BPF_IMM         0x00
 175 #define         BPF_ABS         0x20
 176 #define         BPF_IND         0x40
 177 #define         BPF_MEM         0x60
 178 #define         BPF_LEN         0x80
 179 #define         BPF_MSH         0xa0
 180
 181 /* alu/jmp fields */
 182 #define BPF_OP(code)    ((code) & 0xf0)
 183 #define         BPF_ADD         0x00
 184 #define         BPF_SUB         0x10
 185 #define         BPF_MUL         0x20
 186 #define         BPF_DIV         0x30
 187 #define         BPF_OR          0x40
 188 #define         BPF_AND         0x50
 189 #define         BPF_LSH         0x60
 190 #define         BPF_RSH         0x70
 191 #define         BPF_NEG         0x80
 192 #define         BPF_MOD         0x90
 193 #define         BPF_XOR         0xa0
 194 #define         BPF_JA          0x00
 195 #define         BPF_JEQ         0x10
 196 #define         BPF_JGT         0x20
 197 #define         BPF_JGE         0x30
 198 #define         BPF_JSET        0x40
 199 #define BPF_SRC(code)   ((code) & 0x08)
 200 #define         BPF_K           0x00
 201 #define         BPF_X           0x08
 202
 203 /* ret - BPF_K and BPF_X also apply */
 204 #define BPF_RVAL(code)  ((code) & 0x18)
 205 #define         BPF_A           0x10
 206
 207 /* misc */
 208 #define BPF_MISCOP(code) ((code) & 0xf8)
 209 #define         BPF_TAX         0x00
 210 #define         BPF_TXA         0x80
 211
 212 /*
 213  * The instruction data structure.
 214  */
 215 struct bpf_insn {
 216         u_short         code;
 217         u_char          jt;
 218         u_char          jf;
 219         bpf_u_int32     k;
 220 };
 221
 222 /*
 223  * Macros for insn array initializers.
 224  */
 225 #define BPF_STMT(code, k) { (u_short)(code), 0, 0, k }
 226 #define BPF_JUMP(code, k, jt, jf) { (u_short)(code), jt, jf, k }
 227
 228 /*
 229  * Structure to retrieve available DLTs for the interface.
 230  */
 231 struct bpf_dltlist {
 232         u_int   bfl_len;        /* number of bfd_list array */
 233         u_int   *bfl_list;      /* array of DLTs */
 234 };
 235
 236 #ifdef _KERNEL
 237
 238 struct bpf_if;
 239 struct ifnet;
 240 struct mbuf;
 241
 242 int      bpf_validate(const struct bpf_insn *, int);
 243 void     bpf_tap(struct bpf_if *, u_char *, u_int);
 244 void     bpf_mtap(struct bpf_if *, struct mbuf *);
 245 void     bpf_mtap_family(struct bpf_if *, struct mbuf *m, __uint8_t family);
 246 void     bpf_mtap_hdr(struct bpf_if *, caddr_t, u_int, struct mbuf *, u_int);
 247 void     bpf_ptap(struct bpf_if *, struct mbuf *, const void *, u_int);
 248 void     bpfattach(struct ifnet *, u_int, u_int);
 249 void     bpfattach_dlt(struct ifnet *, u_int, u_int, struct bpf_if **);
 250 void     bpfdetach(struct ifnet *);
 251 void     bpf_gettoken(void);
 252 void     bpf_reltoken(void);
 253
 254 u_int    bpf_filter(const struct bpf_insn *, u_char *, u_int, u_int);
 255
 256 #define BPF_TAP(_ifp,_pkt,_pktlen) do {                                 \
 257         if ((_ifp)->if_bpf) {                                           \
 258                 bpf_gettoken();                                         \
 259                 if ((_ifp)->if_bpf)                                     \
 260                         bpf_tap((_ifp)->if_bpf, (_pkt), (_pktlen));     \
 261                 bpf_reltoken();                                         \
 262         }                                                               \
 263 } while (0)
 264
 265 #define BPF_MTAP(_ifp,_m) do {                                          \
 266         if ((_ifp)->if_bpf) {                                           \
 267                 bpf_gettoken();                                         \
 268                 if ((_ifp)->if_bpf)                                     \
 269                         bpf_mtap((_ifp)->if_bpf, (_m));                 \
 270                 bpf_reltoken();                                         \
 271         }                                                               \
 272 } while (0)
 273
 274 /*
 275  * BPF attach/detach events
 276  */
 277
 278 #include <sys/eventhandler.h>
 279 struct ifnet;
 280
 281 typedef void (*bpf_track_fn)(void *, struct ifnet *, int /* dlt */,
 282     int /* 1 =>'s attach */);
 283 EVENTHANDLER_DECLARE(bpf_track, bpf_track_fn);
 284
 285 #endif  /* _KERNEL */
 286
 287 /*
 288  * Number of scratch memory words (for BPF_LD|BPF_MEM and BPF_ST).
 289  */
 290 #define BPF_MEMWORDS 16
 291
 292 __END_DECLS
 293
 294 #endif  /* !_NET_BPF_H_ */