1 /*
2 * Copyright (c) 1990, 1991, 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
22 /* \summary: Trivial File Transfer Protocol (TFTP) printer */
23
24 #ifdef HAVE_CONFIG_H
25 #include "config.h"
26 #endif
27
28 #include <netdissect-stdinc.h>
29
30 #include <string.h>
31
32 #include "netdissect.h"
33 #include "extract.h"
34
35 /*
36 * Trivial File Transfer Protocol (IEN-133)
37 */
38
39 /*
40 * Packet types.
41 */
42 #define RRQ 01 /* read request */
43 #define WRQ 02 /* write request */
44 #define DATA 03 /* data packet */
45 #define ACK 04 /* acknowledgement */
46 #define TFTP_ERROR 05 /* error code */
47 #define OACK 06 /* option acknowledgement */
48
49 /*
50 * Error codes.
51 */
52 #define EUNDEF 0 /* not defined */
53 #define ENOTFOUND 1 /* file not found */
54 #define EACCESS 2 /* access violation */
55 #define ENOSPACE 3 /* disk full or allocation exceeded */
56 #define EBADOP 4 /* illegal TFTP operation */
57 #define EBADID 5 /* unknown transfer ID */
58 #define EEXISTS 6 /* file already exists */
59 #define ENOUSER 7 /* no such user */
60
61 static const char tstr[] = " [|tftp]";
62
63 /* op code to string mapping */
64 static const struct tok op2str[] = {
65 { RRQ, "RRQ" }, /* read request */
66 { WRQ, "WRQ" }, /* write request */
67 { DATA, "DATA" }, /* data packet */
68 { ACK, "ACK" }, /* acknowledgement */
69 { TFTP_ERROR, "ERROR" }, /* error code */
70 { OACK, "OACK" }, /* option acknowledgement */
71 { 0, NULL }
72 };
73
74 /* error code to string mapping */
75 static const struct tok err2str[] = {
76 { EUNDEF, "EUNDEF" }, /* not defined */
77 { ENOTFOUND, "ENOTFOUND" }, /* file not found */
78 { EACCESS, "EACCESS" }, /* access violation */
79 { ENOSPACE, "ENOSPACE" }, /* disk full or allocation exceeded */
80 { EBADOP, "EBADOP" }, /* illegal TFTP operation */
81 { EBADID, "EBADID" }, /* unknown transfer ID */
82 { EEXISTS, "EEXISTS" }, /* file already exists */
83 { ENOUSER, "ENOUSER" }, /* no such user */
84 { 0, NULL }
85 };
86
87 /*
88 * Print trivial file transfer program requests
89 */
90 void
tftp_print(netdissect_options * ndo,register const u_char * bp,u_int length)91 tftp_print(netdissect_options *ndo,
92 register const u_char *bp, u_int length)
93 {
94 register const char *cp;
95 register int opcode;
96 u_int ui;
97
98 /* Print length */
99 ND_PRINT((ndo, " %d", length));
100
101 /* Print tftp request type */
102 if (length < 2)
103 goto trunc;
104 ND_TCHECK_16BITS(bp);
105 opcode = EXTRACT_16BITS(bp);
106 cp = tok2str(op2str, "tftp-#%d", opcode);
107 ND_PRINT((ndo, " %s", cp));
108 /* Bail if bogus opcode */
109 if (*cp == 't')
110 return;
111 bp += 2;
112 length -= 2;
113
114 switch (opcode) {
115
116 case RRQ:
117 case WRQ:
118 if (length == 0)
119 goto trunc;
120 ND_PRINT((ndo, " "));
121 /* Print filename */
122 ND_PRINT((ndo, "\""));
123 ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
124 ND_PRINT((ndo, "\""));
125 if (ui == 0)
126 goto trunc;
127 bp += ui;
128 length -= ui;
129
130 /* Print the mode - RRQ and WRQ only */
131 if (length == 0)
132 goto trunc; /* no mode */
133 ND_PRINT((ndo, " "));
134 ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
135 if (ui == 0)
136 goto trunc;
137 bp += ui;
138 length -= ui;
139
140 /* Print options, if any */
141 while (length != 0) {
142 ND_TCHECK(*bp);
143 if (*bp != '\0')
144 ND_PRINT((ndo, " "));
145 ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
146 if (ui == 0)
147 goto trunc;
148 bp += ui;
149 length -= ui;
150 }
151 break;
152
153 case OACK:
154 /* Print options */
155 while (length != 0) {
156 ND_TCHECK(*bp);
157 if (*bp != '\0')
158 ND_PRINT((ndo, " "));
159 ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
160 if (ui == 0)
161 goto trunc;
162 bp += ui;
163 length -= ui;
164 }
165 break;
166
167 case ACK:
168 case DATA:
169 if (length < 2)
170 goto trunc; /* no block number */
171 ND_TCHECK_16BITS(bp);
172 ND_PRINT((ndo, " block %d", EXTRACT_16BITS(bp)));
173 break;
174
175 case TFTP_ERROR:
176 /* Print error code string */
177 if (length < 2)
178 goto trunc; /* no error code */
179 ND_TCHECK_16BITS(bp);
180 ND_PRINT((ndo, " %s", tok2str(err2str, "tftp-err-#%d \"",
181 EXTRACT_16BITS(bp))));
182 bp += 2;
183 length -= 2;
184 /* Print error message string */
185 if (length == 0)
186 goto trunc; /* no error message */
187 ND_PRINT((ndo, " \""));
188 ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
189 ND_PRINT((ndo, "\""));
190 if (ui == 0)
191 goto trunc;
192 break;
193
194 default:
195 /* We shouldn't get here */
196 ND_PRINT((ndo, "(unknown #%d)", opcode));
197 break;
198 }
199 return;
200 trunc:
201 ND_PRINT((ndo, "%s", tstr));
202 return;
203 }
204