xref: /freebsd/contrib/tcpdump/print-udld.c (revision 9a0c3479e22feda1bdb2db4b97f9deb1b5fa6269)
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