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 1.16 2004-10-28 00:34:29 hannes 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         printf("%3s ",tok2str(sll_pkttype_values,"?",EXTRACT_16BITS(&sllp->sll_pkttype)));
  57
  58         /*
  59          * XXX - check the link-layer address type value?
  60          * For now, we just assume 6 means Ethernet.
  61          * XXX - print others as strings of hex?
  62          */
  63         if (EXTRACT_16BITS(&sllp->sll_halen) == 6)
  64                 (void)printf("%s ", etheraddr_string(sllp->sll_addr));
  65
  66         if (!qflag)
  67                 (void)printf("ethertype %s (0x%04x), length %u: ",
  68                          tok2str(ethertype_values,"Unknown", EXTRACT_16BITS(&sllp->sll_protocol)),
  69                          EXTRACT_16BITS(&sllp->sll_protocol),
  70                          length);
  71 }
  72
  73 /*
  74  * This is the top level routine of the printer.  'p' points to the
  75  * Linux "cooked capture" header of the packet, 'h->ts' is the timestamp,
  76  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
  77  * is the number of bytes actually captured.
  78  */
  79 u_int
  80 sll_if_print(const struct pcap_pkthdr *h, const u_char *p)
  81 {
  82         u_int caplen = h->caplen;
  83         u_int length = h->len;
  84         register const struct sll_header *sllp;
  85         u_short ether_type;
  86         u_short extracted_ethertype;
  87
  88         if (caplen < SLL_HDR_LEN) {
  89                 /*
  90                  * XXX - this "can't happen" because "pcap-linux.c" always
  91                  * adds this many bytes of header to every packet in a
  92                  * cooked socket capture.
  93                  */
  94                 printf("[|sll]");
  95                 return (caplen);
  96         }
  97
  98         sllp = (const struct sll_header *)p;
  99
 100         if (eflag)
 101                 sll_print(sllp, length);
 102
 103         /*
 104          * Go past the cooked-mode header.
 105          */
 106         length -= SLL_HDR_LEN;
 107         caplen -= SLL_HDR_LEN;
 108         p += SLL_HDR_LEN;
 109
 110         ether_type = ntohs(sllp->sll_protocol);
 111
 112         /*
 113          * Is it (gag) an 802.3 encapsulation, or some non-Ethernet
 114          * packet type?
 115          */
 116         extracted_ethertype = 0;
 117         if (ether_type <= ETHERMTU) {
 118                 /*
 119                  * Yes - what type is it?
 120                  */
 121                 switch (ether_type) {
 122
 123                 case LINUX_SLL_P_802_3:
 124                         /*
 125                          * Ethernet_802.3 IPX frame.
 126                          */
 127                         ipx_print(p, length);
 128                         break;
 129
 130                 case LINUX_SLL_P_802_2:
 131                         /*
 132                          * 802.2.
 133                          * Try to print the LLC-layer header & higher layers.
 134                          */
 135                         if (llc_print(p, length, caplen, NULL, NULL,
 136                             &extracted_ethertype) == 0)
 137                                 goto unknown;   /* unknown LLC type */
 138                         break;
 139
 140                 default:
 141                 unknown:
 142                         /* ether_type not known, print raw packet */
 143                         if (!eflag)
 144                                 sll_print(sllp, length + SLL_HDR_LEN);
 145                         if (extracted_ethertype) {
 146                                 printf("(LLC %s) ",
 147                                etherproto_string(htons(extracted_ethertype)));
 148                         }
 149                         if (!xflag && !qflag)
 150                                 default_print(p, caplen);
 151                         break;
 152                 }
 153         } else if (ether_encap_print(ether_type, p, length, caplen,
 154             &extracted_ethertype) == 0) {
 155                 /* ether_type not known, print raw packet */
 156                 if (!eflag)
 157                         sll_print(sllp, length + SLL_HDR_LEN);
 158                 if (!xflag && !qflag)
 159                         default_print(p, caplen);
 160         }
 161
 162         return (SLL_HDR_LEN);
 163 }