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   1 /*
   2  * Copyright (c) 1993, 1994, 1995, 1996, 1997
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the Computer Systems
  16  *      Engineering Group at Lawrence Berkeley Laboratory.
  17  * 4. Neither the name of the University nor of the Laboratory may be used
  18  *    to endorse or promote products derived from this software without
  19  *    specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) $Header: /tcpdump/master/libpcap/pcap.h,v 1.27 2000-09-18 05:08:02 guy Exp $ (LBL)
  34  */
  35
  36 #ifndef lib_pcap_h
  37 #define lib_pcap_h
  38
  39 #include <sys/types.h>
  40 #include <sys/time.h>
  41
  42 #include <net/bpf.h>
  43
  44 #include <stdio.h>
  45
  46 #ifdef __cplusplus
  47 extern "C" {
  48 #endif
  49
  50 #define PCAP_VERSION_MAJOR 2
  51 #define PCAP_VERSION_MINOR 4
  52
  53 #define PCAP_ERRBUF_SIZE 256
  54
  55 /*
  56  * Compatibility for systems that have a bpf.h that
  57  * predates the bpf typedefs for 64-bit support.
  58  */
  59 #if BPF_RELEASE - 0 < 199406
  60 typedef int bpf_int32;
  61 typedef u_int bpf_u_int32;
  62 #endif
  63
  64 typedef struct pcap pcap_t;
  65 typedef struct pcap_dumper pcap_dumper_t;
  66
  67 /*
  68  * The first record in the file contains saved values for some
  69  * of the flags used in the printout phases of tcpdump.
  70  * Many fields here are 32 bit ints so compilers won't insert unwanted
  71  * padding; these files need to be interchangeable across architectures.
  72  *
  73  * Do not change the format of this structure, in any way (this includes
  74  * changes that only affect the length of fields in this structure).
  75  * Instead:
  76  *
  77  *      introduce a new structure for the new format;
  78  *
  79  *      send mail to "tcpdump-workers@tcpdump.org", requesting a new
  80  *      magic number for your new capture file format, and, when
  81  *      you get the new magic number, put it in "savefile.c";
  82  *
  83  *      use that magic number for save files with the changed file
  84  *      header;
  85  *
  86  *      make the code in "savefile.c" capable of reading files with
  87  *      the old file header as well as files with the new file header
  88  *      (using the magic number to determine the header format).
  89  *
  90  * Then supply the changes to "patches@tcpdump.org", so that future
  91  * versions of libpcap and programs that use it (such as tcpdump) will
  92  * be able to read your new capture file format.
  93  */
  94 struct pcap_file_header {
  95         bpf_u_int32 magic;
  96         u_short version_major;
  97         u_short version_minor;
  98         bpf_int32 thiszone;     /* gmt to local correction */
  99         bpf_u_int32 sigfigs;    /* accuracy of timestamps */
 100         bpf_u_int32 snaplen;    /* max length saved portion of each pkt */
 101         bpf_u_int32 linktype;   /* data link type (PCAP_ENCAP_*) */
 102 };
 103
 104 /*
 105  * Values for "linktype" in the file header.
 106  *
 107  * In the past, these have been DLT_ codes defined by <net/bpf.h>.
 108  * Those codes were used in two places:
 109  *
 110  *      inside BSD kernels, as the value returned by the BIOCGDLT ioctl
 111  *      for "/dev/bpfN" devices;
 112  *
 113  *      inside libpcap capture file headers.
 114  *
 115  * Unfortunately, the various flavors of BSD have not always used the same
 116  * numerical values for the same data types, and various patches to
 117  * libpcap for non-BSD OSes have added their own DLT_ codes for link
 118  * layer encapsulation types seen on those OSes, and those codes have had,
 119  * in some cases, values that were also used, on other platforms, for other
 120  * link layer encapsulation types.
 121  *
 122  * This means that capture files of a type whose numerical DLT_ code
 123  * means different things on different BSDs, or with different versions
 124  * of libpcap, can't always be read on systems other than those like
 125  * the one running on the machine on which the capture was made.
 126  *
 127  * We therefore now, in an attempt to decouple the values supplied by
 128  * BIOCGDLT from the values used in the libpcap file header, define
 129  * a set of PCAP_ENCAP_* codes to be used in the header; "pcap_open_live()"
 130  * in the various "pcap-bpf.c" files should set the "linktype" field of
 131  * the "pcap_t" it returns to a PCAP_ENCAP_* code, not to a DLT_* code.
 132  *
 133  * For those DLT_* codes that have, as far as we know, the same values on
 134  * all platforms (DLT_NULL through DLT_FDDI), we define PCAP_ENCAP_xxx as
 135  * DLT_xxx; this means that captures of those types will continue to use
 136  * the same "linktype" value, and thus will continue to be readable by
 137  * older versions of libpcap.
 138  *
 139  * The other PCAP_ENCAP_* codes are given values starting at 100, in the
 140  * hopes that no DLT_* code will be given one of those values.
 141  *
 142  * In order to ensure that a given PCAP_ENCAP_* code's value will refer to
 143  * the same encapsulation type on all platforms, you should not allocate
 144  * a new PCAP_ENCAP_* value without consulting "tcpdump-workers@tcpdump.org".
 145  * The tcpdump developers will allocate a value for you, and will not
 146  * subsequently allocate it to anybody else; that value will be added to
 147  * the "pcap.h" in the tcpdump.org CVS repository, so that a future
 148  * libpcap release will include it.
 149  *
 150  * You should, if possible, also contribute patches to libpcap and tcpdump
 151  * to handle the new encapsulation type, so that they can also be checked
 152  * into the tcpdump.org CVS repository and so that they will appear in
 153  * future libpcap and tcpdump releases.
 154  *
 155  * PCAP_ENCAP_* codes should not be used inside kernels; DLT_* codes
 156  * should be used inside kernels that support BSD's BPF mechanism (other
 157  * kernels may use other codes, e.g. ARPHRD_* codes in Linux kernels
 158  * and DL_* codes in kernels using DLPI).
 159  */
 160 #define PCAP_ENCAP_NULL         DLT_NULL
 161 #define PCAP_ENCAP_ETHERNET     DLT_EN10MB      /* also for 100Mb and up */
 162 #define PCAP_ENCAP_EXP_ETHERNET DLT_EN3MB       /* 3Mb experimental Ethernet */
 163 #define PCAP_ENCAP_AX25         DLT_AX25
 164 #define PCAP_ENCAP_PRONET       DLT_PRONET
 165 #define PCAP_ENCAP_CHAOS        DLT_CHAOS
 166 #define PCAP_ENCAP_TOKEN_RING   DLT_IEEE802     /* DLT_IEEE802 is used for Token Ring */
 167 #define PCAP_ENCAP_ARCNET       DLT_ARCNET
 168 #define PCAP_ENCAP_SLIP         DLT_SLIP
 169 #define PCAP_ENCAP_PPP          DLT_PPP
 170 #define PCAP_ENCAP_FDDI         DLT_FDDI
 171
 172 #define PCAP_ENCAP_ATM_RFC1483  100             /* LLC/SNAP-encapsulated ATM */
 173 #define PCAP_ENCAP_RAW          101             /* raw IP */
 174 #define PCAP_ENCAP_SLIP_BSDOS   102             /* BSD/OS SLIP BPF header */
 175 #define PCAP_ENCAP_PPP_BSDOS    103             /* BSD/OS PPP BPF header */
 176 #define PCAP_ENCAP_C_HDLC       104             /* Cisco HDLC */
 177 #define PCAP_ENCAP_IEEE802_11   105             /* IEEE 802.11 (wireless) */
 178 #define PCAP_ENCAP_ATM_CLIP     106             /* Linux Classical IP over ATM */
 179
 180 /*
 181  * PCAP_ENCAP_PPP is for use when there might, or might not, be an RFC 1662
 182  * PPP in HDLC-like framing header (with 0xff 0x03 before the PPP protocol
 183  * field) at the beginning of the packet.
 184  *
 185  * This is for use when there is always such a header; the address field
 186  * might be 0xff, for regular PPP, or it might be an address field for Cisco
 187  * point-to-point with HDLC framing as per section 4.3.1 of RFC 1547 ("Cisco
 188  * HDLC").  This is, for example, what you get with NetBSD's DLT_PPP_SERIAL.
 189  */
 190 #define PCAP_ENCAP_PPP_HDLC     107             /* PPP in HDLC-like framing */
 191
 192 /*
 193  * Each packet in the dump file is prepended with this generic header.
 194  * This gets around the problem of different headers for different
 195  * packet interfaces.
 196  */
 197 struct pcap_pkthdr {
 198         struct timeval ts;      /* time stamp */
 199         bpf_u_int32 caplen;     /* length of portion present */
 200         bpf_u_int32 len;        /* length this packet (off wire) */
 201 };
 202
 203 /*
 204  * As returned by the pcap_stats()
 205  */
 206 struct pcap_stat {
 207         u_int ps_recv;          /* number of packets received */
 208         u_int ps_drop;          /* number of packets dropped */
 209         u_int ps_ifdrop;        /* drops by interface XXX not yet supported */
 210 };
 211
 212 typedef void (*pcap_handler)(u_char *, const struct pcap_pkthdr *,
 213                              const u_char *);
 214
 215 char    *pcap_lookupdev(char *);
 216 int     pcap_lookupnet(char *, bpf_u_int32 *, bpf_u_int32 *, char *);
 217 pcap_t  *pcap_open_live(char *, int, int, int, char *);
 218 pcap_t  *pcap_open_dead(int, int);
 219 pcap_t  *pcap_open_offline(const char *, char *);
 220 void    pcap_close(pcap_t *);
 221 int     pcap_loop(pcap_t *, int, pcap_handler, u_char *);
 222 int     pcap_dispatch(pcap_t *, int, pcap_handler, u_char *);
 223 const u_char*
 224         pcap_next(pcap_t *, struct pcap_pkthdr *);
 225 int     pcap_stats(pcap_t *, struct pcap_stat *);
 226 int     pcap_setfilter(pcap_t *, struct bpf_program *);
 227 void    pcap_perror(pcap_t *, char *);
 228 char    *pcap_strerror(int);
 229 char    *pcap_geterr(pcap_t *);
 230 int     pcap_compile(pcap_t *, struct bpf_program *, char *, int,
 231             bpf_u_int32);
 232 int     pcap_compile_nopcap(int, int, struct bpf_program *,
 233             char *, int, bpf_u_int32);
 234 /* XXX */
 235 int     pcap_freecode(pcap_t *, struct bpf_program *);
 236 int     pcap_datalink(pcap_t *);
 237 int     pcap_snapshot(pcap_t *);
 238 int     pcap_is_swapped(pcap_t *);
 239 int     pcap_major_version(pcap_t *);
 240 int     pcap_minor_version(pcap_t *);
 241
 242 /* XXX */
 243 FILE    *pcap_file(pcap_t *);
 244 int     pcap_fileno(pcap_t *);
 245
 246 pcap_dumper_t *pcap_dump_open(pcap_t *, const char *);
 247 void    pcap_dump_close(pcap_dumper_t *);
 248 void    pcap_dump(u_char *, const struct pcap_pkthdr *, const u_char *);
 249
 250 /* XXX this guy lives in the bpf tree */
 251 u_int   bpf_filter(struct bpf_insn *, u_char *, u_int, u_int);
 252 int     bpf_validate(struct bpf_insn *f, int len);
 253 char    *bpf_image(struct bpf_insn *, int);
 254 void    bpf_dump(struct bpf_program *, int);
 255
 256 #ifdef __cplusplus
 257 }
 258 #endif
 259
 260 #endif