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 1.12.2.2 2003-11-16 08:51:44 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 u_int
  96 sll_if_print(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         if (caplen < SLL_HDR_LEN) {
 105                 /*
 106                  * XXX - this "can't happen" because "pcap-linux.c" always
 107                  * adds this many bytes of header to every packet in a
 108                  * cooked socket capture.
 109                  */
 110                 printf("[|sll]");
 111                 return (caplen);
 112         }
 113
 114         sllp = (const struct sll_header *)p;
 115
 116         if (eflag)
 117                 sll_print(sllp, length);
 118
 119         /*
 120          * Go past the cooked-mode header.
 121          */
 122         length -= SLL_HDR_LEN;
 123         caplen -= SLL_HDR_LEN;
 124         p += SLL_HDR_LEN;
 125
 126         ether_type = ntohs(sllp->sll_protocol);
 127
 128         /*
 129          * Is it (gag) an 802.3 encapsulation, or some non-Ethernet
 130          * packet type?
 131          */
 132         extracted_ethertype = 0;
 133         if (ether_type <= ETHERMTU) {
 134                 /*
 135                  * Yes - what type is it?
 136                  */
 137                 switch (ether_type) {
 138
 139                 case LINUX_SLL_P_802_3:
 140                         /*
 141                          * Ethernet_802.3 IPX frame.
 142                          */
 143                         ipx_print(p, length);
 144                         break;
 145
 146                 case LINUX_SLL_P_802_2:
 147                         /*
 148                          * 802.2.
 149                          * Try to print the LLC-layer header & higher layers.
 150                          */
 151                         if (llc_print(p, length, caplen, NULL, NULL,
 152                             &extracted_ethertype) == 0)
 153                                 goto unknown;   /* unknown LLC type */
 154                         break;
 155
 156                 default:
 157                 unknown:
 158                         /* ether_type not known, print raw packet */
 159                         if (!eflag)
 160                                 sll_print(sllp, length + SLL_HDR_LEN);
 161                         if (extracted_ethertype) {
 162                                 printf("(LLC %s) ",
 163                                etherproto_string(htons(extracted_ethertype)));
 164                         }
 165                         if (!xflag && !qflag)
 166                                 default_print(p, caplen);
 167                         break;
 168                 }
 169         } else if (ether_encap_print(ether_type, p, length, caplen,
 170             &extracted_ethertype) == 0) {
 171                 /* ether_type not known, print raw packet */
 172                 if (!eflag)
 173                         sll_print(sllp, length + SLL_HDR_LEN);
 174                 if (!xflag && !qflag)
 175                         default_print(p, caplen);
 176         }
 177
 178         return (SLL_HDR_LEN);
 179 }