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 * UNIDIRECTIONAL LINK DETECTION (UDLD) as per 16 * http://www.ietf.org/internet-drafts/draft-foschiano-udld-02.txt 17 * 18 * Original code by Carles Kishimoto <carles.kishimoto@gmail.com> 19 */ 20 21 #ifdef HAVE_CONFIG_H 22 #include "config.h" 23 #endif 24 25 #include <tcpdump-stdinc.h> 26 27 #include <stdio.h> 28 #include <string.h> 29 30 #include "interface.h" 31 #include "addrtoname.h" 32 #include "extract.h" 33 #include "nlpid.h" 34 35 #define UDLD_HEADER_LEN 4 36 #define UDLD_DEVICE_ID_TLV 0x0001 37 #define UDLD_PORT_ID_TLV 0x0002 38 #define UDLD_ECHO_TLV 0x0003 39 #define UDLD_MESSAGE_INTERVAL_TLV 0x0004 40 #define UDLD_TIMEOUT_INTERVAL_TLV 0x0005 41 #define UDLD_DEVICE_NAME_TLV 0x0006 42 #define UDLD_SEQ_NUMBER_TLV 0x0007 43 44 static struct tok udld_tlv_values[] = { 45 { UDLD_DEVICE_ID_TLV, "Device-ID TLV"}, 46 { UDLD_PORT_ID_TLV, "Port-ID TLV"}, 47 { UDLD_ECHO_TLV, "Echo TLV"}, 48 { UDLD_MESSAGE_INTERVAL_TLV, "Message Interval TLV"}, 49 { UDLD_TIMEOUT_INTERVAL_TLV, "Timeout Interval TLV"}, 50 { UDLD_DEVICE_NAME_TLV, "Device Name TLV"}, 51 { UDLD_SEQ_NUMBER_TLV,"Sequence Number TLV"}, 52 { 0, NULL} 53 }; 54 55 static struct tok udld_code_values[] = { 56 { 0x00, "Reserved"}, 57 { 0x01, "Probe message"}, 58 { 0x02, "Echo message"}, 59 { 0x03, "Flush message"}, 60 { 0, NULL} 61 }; 62 63 static struct tok udld_flags_values[] = { 64 { 0x00, "RT"}, 65 { 0x01, "RSY"}, 66 { 0, NULL} 67 }; 68 69 /* 70 * 71 * 0 1 2 3 72 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 73 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 74 * | Ver | Opcode | Flags | Checksum | 75 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 76 * | List of TLVs (variable length list) | 77 * | ... | 78 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 79 * 80 */ 81 82 #define UDLD_EXTRACT_VERSION(x) (((x)&0xe0)>>5) 83 #define UDLD_EXTRACT_OPCODE(x) ((x)&0x1f) 84 85 void 86 udld_print (const u_char *pptr, u_int length) 87 { 88 int code, type, len; 89 const u_char *tptr; 90 91 if (length < UDLD_HEADER_LEN) 92 goto trunc; 93 94 tptr = pptr; 95 96 if (!TTEST2(*tptr, UDLD_HEADER_LEN)) 97 goto trunc; 98 99 code = UDLD_EXTRACT_OPCODE(*tptr); 100 101 printf("UDLDv%u, Code %s (%x), Flags [%s] (0x%02x), length %u", 102 UDLD_EXTRACT_VERSION(*tptr), 103 tok2str(udld_code_values, "Reserved", code), 104 code, 105 bittok2str(udld_flags_values, "none", *(tptr+1)), 106 *(tptr+1), 107 length); 108 109 /* 110 * In non-verbose mode, just print version and opcode type 111 */ 112 if (vflag < 1) { 113 return; 114 } 115 116 printf("\n\tChecksum 0x%04x (unverified)", EXTRACT_16BITS(tptr+2)); 117 118 tptr += UDLD_HEADER_LEN; 119 120 while (tptr < (pptr+length)) { 121 122 if (!TTEST2(*tptr, 4)) 123 goto trunc; 124 125 type = EXTRACT_16BITS(tptr); 126 len = EXTRACT_16BITS(tptr+2); 127 len -= 4; 128 tptr += 4; 129 130 /* infinite loop check */ 131 if (type == 0 || len == 0) { 132 return; 133 } 134 135 printf("\n\t%s (0x%04x) TLV, length %u", 136 tok2str(udld_tlv_values, "Unknown", type), 137 type, len); 138 139 switch (type) { 140 case UDLD_DEVICE_ID_TLV: 141 case UDLD_PORT_ID_TLV: 142 case UDLD_ECHO_TLV: 143 case UDLD_DEVICE_NAME_TLV: 144 printf(", %s", tptr); 145 break; 146 147 case UDLD_MESSAGE_INTERVAL_TLV: 148 case UDLD_TIMEOUT_INTERVAL_TLV: 149 printf(", %us", (*tptr)); 150 break; 151 152 case UDLD_SEQ_NUMBER_TLV: 153 printf(", %u", EXTRACT_32BITS(tptr)); 154 break; 155 156 default: 157 break; 158 } 159 tptr += len; 160 } 161 162 return; 163 164 trunc: 165 printf("[|udld]"); 166 } 167 168 /* 169 * Local Variables: 170 * c-style: whitesmith 171 * c-basic-offset: 4 172 * End: 173 */ 174