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@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