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