The Tcpdump Group git mirrors - tcpdump/blob - print-sll.c

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 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: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21 #ifndef lint
  22 static const char rcsid[] =
  23     "@(#) $Header: /tcpdump/master/tcpdump/print-sll.c,v 1.10 2002-12-18 08:53:24 guy Exp $ (LBL)";
  24 #endif
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include <tcpdump-stdinc.h>
  31
  32 #include <stdio.h>
  33 #include <string.h>
  34 #include <pcap.h>
  35
  36 #include "interface.h"
  37 #include "addrtoname.h"
  38 #include "ethertype.h"
  39
  40 #include "ether.h"
  41 #include "sll.h"
  42
  43 static inline void
  44 sll_print(register const struct sll_header *sllp, u_int length)
  45 {
  46         u_short halen;
  47
  48         switch (ntohs(sllp->sll_pkttype)) {
  49
  50         case LINUX_SLL_HOST:
  51                 (void)printf("< ");
  52                 break;
  53
  54         case LINUX_SLL_BROADCAST:
  55                 (void)printf("B ");
  56                 break;
  57
  58         case LINUX_SLL_MULTICAST:
  59                 (void)printf("M ");
  60                 break;
  61
  62         case LINUX_SLL_OTHERHOST:
  63                 (void)printf("P ");
  64                 break;
  65
  66         case LINUX_SLL_OUTGOING:
  67                 (void)printf("> ");
  68                 break;
  69
  70         default:
  71                 (void)printf("? ");
  72                 break;
  73         }
  74
  75         /*
  76          * XXX - check the link-layer address type value?
  77          * For now, we just assume 6 means Ethernet.
  78          * XXX - print others as strings of hex?
  79          */
  80         halen = ntohs(sllp->sll_halen);
  81         if (halen == 6)
  82                 (void)printf("%s ", etheraddr_string(sllp->sll_addr));
  83
  84         if (!qflag)
  85                 (void)printf("%s ", etherproto_string(sllp->sll_protocol));
  86         (void)printf("%d: ", length);
  87 }
  88
  89 /*
  90  * This is the top level routine of the printer.  'p' points to the
  91  * Linux "cooked capture" header of the packet, 'h->ts' is the timestamp,
  92  * 'h->length' is the length of the packet off the wire, and 'h->caplen'
  93  * is the number of bytes actually captured.
  94  */
  95 void
  96 sll_if_print(u_char *user _U_, const struct pcap_pkthdr *h, const u_char *p)
  97 {
  98         u_int caplen = h->caplen;
  99         u_int length = h->len;
 100         register const struct sll_header *sllp;
 101         u_short ether_type;
 102         u_short extracted_ethertype;
 103
 104         ++infodelay;
 105         ts_print(&h->ts);
 106
 107         if (caplen < SLL_HDR_LEN) {
 108                 /*
 109                  * XXX - this "can't happen" because "pcap-linux.c" always
 110                  * adds this many bytes of header to every packet in a
 111                  * cooked socket capture.
 112                  */
 113                 printf("[|sll]");
 114                 goto out;
 115         }
 116
 117         sllp = (const struct sll_header *)p;
 118
 119         if (eflag)
 120                 sll_print(sllp, length);
 121
 122         /*
 123          * Some printers want to check that they're not walking off the
 124          * end of the packet.
 125          * Rather than pass it all the way down, we set this global.
 126          */
 127         snapend = p + caplen;
 128
 129         length -= SLL_HDR_LEN;
 130         caplen -= SLL_HDR_LEN;
 131         p += SLL_HDR_LEN;
 132
 133         ether_type = ntohs(sllp->sll_protocol);
 134
 135         /*
 136          * Is it (gag) an 802.3 encapsulation, or some non-Ethernet
 137          * packet type?
 138          */
 139         extracted_ethertype = 0;
 140         if (ether_type <= ETHERMTU) {
 141                 /*
 142                  * Yes - what type is it?
 143                  */
 144                 switch (ether_type) {
 145
 146                 case LINUX_SLL_P_802_3:
 147                         /*
 148                          * Ethernet_802.3 IPX frame.
 149                          */
 150                         ipx_print(p, length);
 151                         break;
 152
 153                 case LINUX_SLL_P_802_2:
 154                         /*
 155                          * 802.2.
 156                          * Try to print the LLC-layer header & higher layers.
 157                          */
 158                         if (llc_print(p, length, caplen, NULL, NULL,
 159                             &extracted_ethertype) == 0)
 160                                 goto unknown;   /* unknown LLC type */
 161                         break;
 162
 163                 default:
 164                 unknown:
 165                         /* ether_type not known, print raw packet */
 166                         if (!eflag)
 167                                 sll_print(sllp, length + SLL_HDR_LEN);
 168                         if (extracted_ethertype) {
 169                                 printf("(LLC %s) ",
 170                                etherproto_string(htons(extracted_ethertype)));
 171                         }
 172                         if (!xflag && !qflag)
 173                                 default_print(p, caplen);
 174                         break;
 175                 }
 176         } else if (ether_encap_print(ether_type, p, length, caplen,
 177             &extracted_ethertype) == 0) {
 178                 /* ether_type not known, print raw packet */
 179                 if (!eflag)
 180                         sll_print(sllp, length + SLL_HDR_LEN);
 181                 if (!xflag && !qflag)
 182                         default_print(p, caplen);
 183         }
 184         if (xflag)
 185                 default_print(p, caplen);
 186  out:
 187         putchar('\n');
 188         --infodelay;
 189         if (infoprint)
 190                 info(0);
 191 }