external/bsd/tcpdump/dist/print-cip.c

   1 /*
   2  * Marko Kiiskila carnil@cs.tut.fi
   3  *
   4  * Tampere University of Technology - Telecommunications Laboratory
   5  *
   6  * Permission to use, copy, modify and distribute this
   7  * software and its documentation is hereby granted,
   8  * provided that both the copyright notice and this
   9  * permission notice appear in all copies of the software,
  10  * derivative works or modified versions, and any portions
  11  * thereof, that both notices appear in supporting
  12  * documentation, and that the use of this software is
  13  * acknowledged in any publications resulting from using
  14  * the software.
  15  *
  16  * TUT ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  17  * CONDITION AND DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  18  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS
  19  * SOFTWARE.
  20  *
  21  */
  22
  23 #include <sys/cdefs.h>
  24 #ifndef lint
  25 __RCSID("$NetBSD: print-cip.c,v 1.4 2014/11/20 03:05:03 christos Exp $");
  26 #endif
  27
  28 #define NETDISSECT_REWORKED
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #include <string.h>
  34
  35 #include <tcpdump-stdinc.h>
  36
  37 #include "interface.h"
  38 #include "addrtoname.h"
  39
  40 #define RFC1483LLC_LEN  8
  41
  42 static const unsigned char rfcllc[] = {
  43         0xaa,   /* DSAP: non-ISO */
  44         0xaa,   /* SSAP: non-ISO */
  45         0x03,   /* Ctrl: Unnumbered Information Command PDU */
  46         0x00,   /* OUI: EtherType */
  47         0x00,
  48         0x00 };
  49
  50 static inline void
  51 cip_print(netdissect_options *ndo, int length)
  52 {
  53         /*
  54          * There is no MAC-layer header, so just print the length.
  55          */
  56         ND_PRINT((ndo, "%d: ", length));
  57 }
  58
  59 /*
  60  * This is the top level routine of the printer.  'p' points
  61  * to the LLC/SNAP or raw header of the packet, 'h->ts' is the timestamp,
  62  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
  63  * is the number of bytes actually captured.
  64  */
  65 u_int
  66 cip_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
  67 {
  68         u_int caplen = h->caplen;
  69         u_int length = h->len;
  70         u_short extracted_ethertype;
  71
  72         if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) {
  73                 ND_PRINT((ndo, "[|cip]"));
  74                 return (0);
  75         }
  76
  77         if (ndo->ndo_eflag)
  78                 cip_print(ndo, length);
  79
  80         if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) {
  81                 /*
  82                  * LLC header is present.  Try to print it & higher layers.
  83                  */
  84                 if (llc_print(ndo, p, length, caplen, NULL, NULL,
  85                     &extracted_ethertype) == 0) {
  86                         /* ether_type not known, print raw packet */
  87                         if (!ndo->ndo_eflag)
  88                                 cip_print(ndo, length);
  89                         if (extracted_ethertype) {
  90                                 ND_PRINT((ndo, "(LLC %s) ",
  91                                etherproto_string(htons(extracted_ethertype))));
  92                         }
  93                         if (!ndo->ndo_suppress_default_print)
  94                                 ND_DEFAULTPRINT(p, caplen);
  95                 }
  96         } else {
  97                 /*
  98                  * LLC header is absent; treat it as just IP.
  99                  */
 100                 ip_print(ndo, p, length);
 101         }
 102
 103         return (0);
 104 }
 105
 106
 107 /*
 108  * Local Variables:
 109  * c-style: whitesmith
 110  * c-basic-offset: 8
 111  * End:
 112  */