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[] _U_ =
  23     "@(#) $Header: /tcpdump/master/tcpdump/print-sll.c,v 1.18 2005-07-07 01:22:21 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 #include "extract.h"
  40
  41 #include "ether.h"
  42 #include "sll.h"
  43
  44 const struct tok sll_pkttype_values[] = {
  45     { LINUX_SLL_HOST, "In" },
  46     { LINUX_SLL_BROADCAST, "B" },
  47     { LINUX_SLL_MULTICAST, "M" },
  48     { LINUX_SLL_OTHERHOST, "P" },
  49     { LINUX_SLL_OUTGOING, "Out" },
  50     { 0, NULL}
  51 };
  52
  53 static inline void
  54 sll_print(register const struct sll_header *sllp, u_int length)
  55 {
  56         u_short ether_type;
  57
  58         printf("%3s ",tok2str(sll_pkttype_values,"?",EXTRACT_16BITS(&sllp->sll_pkttype)));
  59
  60         /*
  61          * XXX - check the link-layer address type value?
  62          * For now, we just assume 6 means Ethernet.
  63          * XXX - print others as strings of hex?
  64          */
  65         if (EXTRACT_16BITS(&sllp->sll_halen) == 6)
  66                 (void)printf("%s ", etheraddr_string(sllp->sll_addr));
  67
  68         if (!qflag) {
  69                 ether_type = EXTRACT_16BITS(&sllp->sll_protocol);
  70
  71                 if (ether_type <= ETHERMTU) {
  72                         /*
  73                          * Not an Ethernet type; what type is it?
  74                          */
  75                         switch (ether_type) {
  76
  77                         case LINUX_SLL_P_802_3:
  78                                 /*
  79                                  * Ethernet_802.3 IPX frame.
  80                                  */
  81                                 (void)printf("802.3");
  82                                 break;
  83
  84                         case LINUX_SLL_P_802_2:
  85                                 /*
  86                                  * 802.2.
  87                                  */
  88                                 (void)printf("802.3");
  89                                 break;
  90
  91                         default:
  92                                 /*
  93                                  * What is it?
  94                                  */
  95                                 (void)printf("ethertype Unknown (0x%04x)",
  96                                     ether_type);
  97                                 break;
  98                         }
  99                 } else {
 100                         (void)printf("ethertype %s (0x%04x)",
 101                             tok2str(ethertype_values, "Unknown", ether_type),
 102                             ether_type);
 103                 }
 104                 (void)printf(", length %u: ", length);
 105         }
 106 }
 107
 108 /*
 109  * This is the top level routine of the printer.  'p' points to the
 110  * Linux "cooked capture" header of the packet, 'h->ts' is the timestamp,
 111  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 112  * is the number of bytes actually captured.
 113  */
 114 u_int
 115 sll_if_print(const struct pcap_pkthdr *h, const u_char *p)
 116 {
 117         u_int caplen = h->caplen;
 118         u_int length = h->len;
 119         register const struct sll_header *sllp;
 120         u_short ether_type;
 121         u_short extracted_ethertype;
 122
 123         if (caplen < SLL_HDR_LEN) {
 124                 /*
 125                  * XXX - this "can't happen" because "pcap-linux.c" always
 126                  * adds this many bytes of header to every packet in a
 127                  * cooked socket capture.
 128                  */
 129                 printf("[|sll]");
 130                 return (caplen);
 131         }
 132
 133         sllp = (const struct sll_header *)p;
 134
 135         if (eflag)
 136                 sll_print(sllp, length);
 137
 138         /*
 139          * Go past the cooked-mode header.
 140          */
 141         length -= SLL_HDR_LEN;
 142         caplen -= SLL_HDR_LEN;
 143         p += SLL_HDR_LEN;
 144
 145         ether_type = ntohs(sllp->sll_protocol);
 146
 147         /*
 148          * Is it (gag) an 802.3 encapsulation, or some non-Ethernet
 149          * packet type?
 150          */
 151         extracted_ethertype = 0;
 152         if (ether_type <= ETHERMTU) {
 153                 /*
 154                  * Yes - what type is it?
 155                  */
 156                 switch (ether_type) {
 157
 158                 case LINUX_SLL_P_802_3:
 159                         /*
 160                          * Ethernet_802.3 IPX frame.
 161                          */
 162                         ipx_print(p, length);
 163                         break;
 164
 165                 case LINUX_SLL_P_802_2:
 166                         /*
 167                          * 802.2.
 168                          * Try to print the LLC-layer header & higher layers.
 169                          */
 170                         if (llc_print(p, length, caplen, NULL, NULL,
 171                             &extracted_ethertype) == 0)
 172                                 goto unknown;   /* unknown LLC type */
 173                         break;
 174
 175                 default:
 176                 unknown:
 177                         /* ether_type not known, print raw packet */
 178                         if (!eflag)
 179                                 sll_print(sllp, length + SLL_HDR_LEN);
 180                         if (extracted_ethertype) {
 181                                 printf("(LLC %s) ",
 182                                etherproto_string(htons(extracted_ethertype)));
 183                         }
 184                         if (!suppress_default_print)
 185                                 default_print(p, caplen);
 186                         break;
 187                 }
 188         } else if (ether_encap_print(ether_type, p, length, caplen,
 189             &extracted_ethertype) == 0) {
 190                 /* ether_type not known, print raw packet */
 191                 if (!eflag)
 192                         sll_print(sllp, length + SLL_HDR_LEN);
 193                 if (!suppress_default_print)
 194                         default_print(p, caplen);
 195         }
 196
 197         return (SLL_HDR_LEN);
 198 }