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 1.3 2000-01-09 09:59:15 assar Exp $ (LBL)";
  26 #endif
  27
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <sys/param.h>
  33 #include <sys/time.h>
  34 #include <sys/types.h>
  35 #include <sys/socket.h>
  36
  37 #include <net/if.h>
  38
  39 #include <netinet/in.h>
  40 #include <netinet/if_ether.h>
  41 #include <netinet/in_systm.h>
  42 #include <netinet/ip.h>
  43 #include <netinet/ip_var.h>
  44 #include <netinet/udp.h>
  45 #include <netinet/udp_var.h>
  46 #include <netinet/tcp.h>
  47
  48 #include <stdio.h>
  49 #include <pcap.h>
  50
  51 #include "interface.h"
  52 #include "addrtoname.h"
  53
  54 const u_char *packetp;
  55 const u_char *snapend;
  56
  57 #define RFC1483LLC_LEN 8
  58
  59 static unsigned char rfcllc[] = {
  60   0xaa,   /* DSAP: non-ISO */
  61   0xaa,   /* SSAP: non-ISO */
  62   0x03,   /* Ctrl: Unnumbered Information Command PDU */
  63   0x00,   /* OUI: EtherType */
  64   0x00,
  65   0x00 };
  66
  67 static inline void
  68 cip_print(register const u_char *bp, int length)
  69 {
  70   int i;
  71
  72   if (memcmp(rfcllc, bp, sizeof(rfcllc))) {
  73     if (qflag) {
  74       for(i=0;i<RFC1483LLC_LEN;i++)
  75         (void)printf("%2.2x ",bp[i]);
  76     } else {
  77       for(i=0;i<RFC1483LLC_LEN-2;i++)
  78         (void)printf("%2.2x ",bp[i]);
  79       etherproto_string(((u_short*)bp)[3]);
  80     }
  81   } else {
  82     if (qflag)
  83       (void)printf("(null encapsulation)");
  84     else {
  85       (void)printf("(null encap)");
  86       etherproto_string(ETHERTYPE_IP);
  87     }
  88   }
  89 }
  90
  91 /*
  92  * This is the top level routine of the printer.  'p' is the points
  93  * to the raw header of the packet, 'tvp' is the timestamp,
  94  * 'length' is the length of the packet off the wire, and 'caplen'
  95  * is the number of bytes actually captured.
  96  */
  97 void
  98 cip_if_print(u_char *user, const struct pcap_pkthdr *h, const u_char *p)
  99 {
 100         int caplen = h->caplen;
 101         int length = h->len;
 102         u_short ether_type;
 103         u_short extracted_ethertype;
 104         u_short *bp;
 105
 106         ts_print(&h->ts);
 107
 108         if (memcmp(rfcllc, p, sizeof(rfcllc))==0 && caplen < RFC1483LLC_LEN) {
 109                 printf("[|cip]");
 110                 goto out;
 111         }
 112
 113         if (eflag)
 114           cip_print(p, length);
 115
 116         /*
 117          * Some printers want to get back at the ethernet addresses,
 118          * and/or check that they're not walking off the end of the packet.
 119          * Rather than pass them all the way down, we set these globals.
 120          */
 121         packetp = p;
 122         snapend = p + caplen;
 123
 124         if (memcmp(rfcllc, p, sizeof(rfcllc))==0) {
 125           length -= RFC1483LLC_LEN;
 126           caplen -= RFC1483LLC_LEN;
 127           bp = (u_short*)p;
 128           p += RFC1483LLC_LEN;
 129           ether_type = ntohs(bp[3]);
 130         } else
 131           ether_type = ETHERTYPE_IP;
 132
 133         /*
 134          * Is it (gag) an 802.3 encapsulation?
 135          */
 136         extracted_ethertype = 0;
 137         if (ether_type < ETHERMTU) {
 138                 /* Try to print the LLC-layer header & higher layers */
 139                 if (llc_print(p, length, caplen, NULL, NULL)==0) {
 140                         /* ether_type not known, print raw packet */
 141                         if (!eflag)
 142                                 cip_print((u_char *)bp, length);
 143                         if (extracted_ethertype) {
 144                                 printf("(LLC %s) ",
 145                                etherproto_string(htons(extracted_ethertype)));
 146                         }
 147                         if (!xflag && !qflag)
 148                                 default_print(p, caplen);
 149                 }
 150         } else if (ether_encap_print(ether_type, p, length, caplen) == 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 }