The Tcpdump Group git mirrors - tcpdump/blob - 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 #ifndef lint
  24 static const char rcsid[] =
  25     "@(#) $Header: /tcpdump/master/tcpdump/print-cip.c,v 1.16 2001-09-23 21:52:38 guy Exp $ (LBL)";
  26 #endif
  27
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <string.h>
  33
  34 #include <sys/param.h>
  35 #include <sys/time.h>
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38
  39
  40 #include <netinet/in.h>
  41
  42 #include <stdio.h>
  43 #include <pcap.h>
  44
  45 #include "interface.h"
  46 #include "addrtoname.h"
  47 #include "ethertype.h"
  48 #include "ether.h"
  49
  50 #define RFC1483LLC_LEN  8
  51
  52 static unsigned char rfcllc[] = {
  53         0xaa,   /* DSAP: non-ISO */
  54         0xaa,   /* SSAP: non-ISO */
  55         0x03,   /* Ctrl: Unnumbered Information Command PDU */
  56         0x00,   /* OUI: EtherType */
  57         0x00,
  58         0x00 };
  59
  60 static inline void
  61 cip_print(register const u_char *bp, int length)
  62 {
  63         /*
  64          * There is no MAC-layer header, so just print the length.
  65          */
  66         printf("%d: ", length);
  67 }
  68
  69 /*
  70  * This is the top level routine of the printer.  'p' is the points
  71  * to the raw header of the packet, 'tvp' is the timestamp,
  72  * 'length' is the length of the packet off the wire, and 'caplen'
  73  * is the number of bytes actually captured.
  74  */
  75 void
  76 cip_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
  77 {
  78         u_int caplen = h->caplen;
  79         u_int length = h->len;
  80         u_short extracted_ethertype;
  81
  82         ++infodelay;
  83         ts_print(&h->ts);
  84
  85         if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) {
  86                 printf("[|cip]");
  87                 goto out;
  88         }
  89
  90         if (eflag)
  91                 cip_print(p, length);
  92
  93         /*
  94          * Some printers want to get back at the ethernet addresses,
  95          * and/or check that they're not walking off the end of the packet.
  96          * Rather than pass them all the way down, we set these globals.
  97          */
  98         packetp = p;
  99         snapend = p + caplen;
 100
 101         if (memcmp(rfcllc, p, sizeof(rfcllc)) == 0) {
 102                 /*
 103                  * LLC header is present.  Try to print it & higher layers.
 104                  */
 105                 if (llc_print(p, length, caplen, NULL, NULL,
 106                     &extracted_ethertype) == 0) {
 107                         /* ether_type not known, print raw packet */
 108                         if (!eflag)
 109                                 cip_print(p, length);
 110                         if (extracted_ethertype) {
 111                                 printf("(LLC %s) ",
 112                                etherproto_string(htons(extracted_ethertype)));
 113                         }
 114                         if (!xflag && !qflag)
 115                                 default_print(p, caplen);
 116                 }
 117         } else {
 118                 /*
 119                  * LLC header is absent; treat it as just IP.
 120                  */
 121                 ip_print(p, length);
 122         }
 123
 124         if (xflag)
 125                 default_print(p, caplen);
 126  out:
 127         putchar('\n');
 128         --infodelay;
 129         if (infoprint)
 130                 info(0);
 131 }