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      1 /*
      2  * Copyright (c) 1998-2007 The TCPDUMP project
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that: (1) source code
      6  * distributions retain the above copyright notice and this paragraph
      7  * in its entirety, and (2) distributions including binary code include
      8  * the above copyright notice and this paragraph in its entirety in
      9  * the documentation or other materials provided with the distribution.
     10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
     11  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
     12  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     13  * FOR A PARTICULAR PURPOSE.
     14  *
     15  * Original code by Carles Kishimoto <carles.kishimoto (at) gmail.com>
     16  */
     17 
     18 /* \summary: Dynamic Trunking Protocol (DTP) printer */
     19 
     20 #ifdef HAVE_CONFIG_H
     21 #include "config.h"
     22 #endif
     23 
     24 #include <netdissect-stdinc.h>
     25 
     26 #include "netdissect.h"
     27 #include "addrtoname.h"
     28 #include "extract.h"
     29 
     30 static const char tstr[] = " [|dtp]";
     31 
     32 #define DTP_HEADER_LEN			1
     33 #define DTP_DOMAIN_TLV			0x0001
     34 #define DTP_STATUS_TLV			0x0002
     35 #define DTP_DTP_TYPE_TLV		0x0003
     36 #define DTP_NEIGHBOR_TLV		0x0004
     37 
     38 static const struct tok dtp_tlv_values[] = {
     39     { DTP_DOMAIN_TLV, "Domain TLV"},
     40     { DTP_STATUS_TLV, "Status TLV"},
     41     { DTP_DTP_TYPE_TLV, "DTP type TLV"},
     42     { DTP_NEIGHBOR_TLV, "Neighbor TLV"},
     43     { 0, NULL}
     44 };
     45 
     46 void
     47 dtp_print (netdissect_options *ndo, const u_char *pptr, u_int length)
     48 {
     49     int type, len;
     50     const u_char *tptr;
     51 
     52     if (length < DTP_HEADER_LEN)
     53         goto trunc;
     54 
     55     tptr = pptr;
     56 
     57     ND_TCHECK2(*tptr, DTP_HEADER_LEN);
     58 
     59     ND_PRINT((ndo, "DTPv%u, length %u",
     60            (*tptr),
     61            length));
     62 
     63     /*
     64      * In non-verbose mode, just print version.
     65      */
     66     if (ndo->ndo_vflag < 1) {
     67 	return;
     68     }
     69 
     70     tptr += DTP_HEADER_LEN;
     71 
     72     while (tptr < (pptr+length)) {
     73 
     74         ND_TCHECK2(*tptr, 4);
     75 	type = EXTRACT_16BITS(tptr);
     76         len  = EXTRACT_16BITS(tptr+2);
     77        /* XXX: should not be but sometimes it is, see the test captures */
     78         if (type == 0)
     79             return;
     80         ND_PRINT((ndo, "\n\t%s (0x%04x) TLV, length %u",
     81                tok2str(dtp_tlv_values, "Unknown", type),
     82                type, len));
     83 
     84         /* infinite loop check */
     85         if (len < 4)
     86             goto invalid;
     87         ND_TCHECK2(*tptr, len);
     88 
     89         switch (type) {
     90 	case DTP_DOMAIN_TLV:
     91 		ND_PRINT((ndo, ", "));
     92 		fn_printzp(ndo, tptr+4, len-4, pptr+length);
     93 		break;
     94 
     95 	case DTP_STATUS_TLV:
     96 	case DTP_DTP_TYPE_TLV:
     97                 if (len < 5)
     98                     goto invalid;
     99                 ND_PRINT((ndo, ", 0x%x", *(tptr+4)));
    100                 break;
    101 
    102 	case DTP_NEIGHBOR_TLV:
    103                 if (len < 10)
    104                     goto invalid;
    105                 ND_PRINT((ndo, ", %s", etheraddr_string(ndo, tptr+4)));
    106                 break;
    107 
    108         default:
    109             break;
    110         }
    111         tptr += len;
    112     }
    113 
    114     return;
    115 
    116  invalid:
    117     ND_PRINT((ndo, "%s", istr));
    118     return;
    119  trunc:
    120     ND_PRINT((ndo, "%s", tstr));
    121 }
    122 
    123 /*
    124  * Local Variables:
    125  * c-style: whitesmith
    126  * c-basic-offset: 4
    127  * End:
    128  */
    129