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 1.12 2001-03-19 03:58:10 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 const u_char *packetp;
  51 const u_char *snapend;
  52
  53 #define RFC1483LLC_LEN  8
  54
  55 static unsigned char rfcllc[] = {
  56         0xaa,   /* DSAP: non-ISO */
  57         0xaa,   /* SSAP: non-ISO */
  58         0x03,   /* Ctrl: Unnumbered Information Command PDU */
  59         0x00,   /* OUI: EtherType */
  60         0x00,
  61         0x00 };
  62
  63 static inline void
  64 cip_print(register const u_char *bp, int length)
  65 {
  66         int i;
  67
  68         if (memcmp(rfcllc, bp, sizeof(rfcllc))) {
  69                 if (qflag) {
  70                         for (i = 0;i < RFC1483LLC_LEN; i++)
  71                         (void)printf("%2.2x ",bp[i]);
  72                 } else {
  73                         for (i = 0;i < RFC1483LLC_LEN - 2; i++)
  74                                 (void)printf("%2.2x ",bp[i]);
  75                         etherproto_string(((u_short*)bp)[3]);
  76                 }
  77         } else {
  78                 if (qflag)
  79                         (void)printf("(null encapsulation)");
  80                 else {
  81                         (void)printf("(null encap)");
  82                         etherproto_string(ETHERTYPE_IP);
  83                 }
  84         }
  85 }
  86
  87 /*
  88  * This is the top level routine of the printer.  'p' is the points
  89  * to the raw header of the packet, 'tvp' is the timestamp,
  90  * 'length' is the length of the packet off the wire, and 'caplen'
  91  * is the number of bytes actually captured.
  92  */
  93 void
  94 cip_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
  95 {
  96         int caplen = h->caplen;
  97         int length = h->len;
  98         u_short ether_type;
  99         u_short extracted_ethertype;
 100         u_short *bp;
 101
 102         ts_print(&h->ts);
 103
 104         if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) {
 105                 printf("[|cip]");
 106                 goto out;
 107         }
 108
 109         if (eflag)
 110                 cip_print(p, length);
 111
 112         /*
 113          * Some printers want to get back at the ethernet addresses,
 114          * and/or check that they're not walking off the end of the packet.
 115          * Rather than pass them all the way down, we set these globals.
 116          */
 117         packetp = p;
 118         snapend = p + caplen;
 119
 120         if (memcmp(rfcllc, p, sizeof(rfcllc))==0) {
 121                 length -= RFC1483LLC_LEN;
 122                 caplen -= RFC1483LLC_LEN;
 123                 bp = (u_short *)p;
 124                 p += RFC1483LLC_LEN;
 125                 ether_type = ntohs(bp[3]);
 126         } else {
 127                 ether_type = ETHERTYPE_IP;
 128                 bp = (u_short *)p;
 129         }
 130
 131         /*
 132          * Is it (gag) an 802.3 encapsulation?
 133          */
 134         extracted_ethertype = 0;
 135         if (ether_type < ETHERMTU) {
 136                 /* Try to print the LLC-layer header & higher layers */
 137                 if (llc_print(p, length, caplen, NULL, NULL,
 138                     &extracted_ethertype)==0) {
 139                         /* ether_type not known, print raw packet */
 140                         if (!eflag)
 141                                 cip_print((u_char *)bp, length + RFC1483LLC_LEN);
 142                         if (extracted_ethertype) {
 143                                 printf("(LLC %s) ",
 144                                etherproto_string(htons(extracted_ethertype)));
 145                         }
 146                         if (!xflag && !qflag)
 147                                 default_print(p, caplen);
 148                 }
 149         } else if (ether_encap_print(ether_type, p, length, caplen,
 150             &extracted_ethertype) == 0) {
 151                 /* ether_type not known, print raw packet */
 152                 if (!eflag)
 153                         cip_print((u_char *)bp, length + RFC1483LLC_LEN);
 154                 if (!xflag && !qflag)
 155                         default_print(p, caplen);
 156         }
 157         if (xflag)
 158                 default_print(p, caplen);
 159  out:
 160         putchar('\n');
 161 }