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 #include <sys/cdefs.h> 25 #ifndef lint 26 __RCSID("$NetBSD: print-tftp.c,v 1.6 2017/01/24 23:29:14 christos Exp $"); 27 #endif 28 29 #ifdef HAVE_CONFIG_H 30 #include "config.h" 31 #endif 32 33 #include <netdissect-stdinc.h> 34 35 #include <string.h> 36 37 #include "netdissect.h" 38 #include "extract.h" 39 40 /* 41 * Trivial File Transfer Protocol (IEN-133) 42 */ 43 44 /* 45 * Packet types. 46 */ 47 #define RRQ 01 /* read request */ 48 #define WRQ 02 /* write request */ 49 #define DATA 03 /* data packet */ 50 #define ACK 04 /* acknowledgement */ 51 #define TFTP_ERROR 05 /* error code */ 52 #define OACK 06 /* option acknowledgement */ 53 54 struct tftphdr { 55 unsigned short th_opcode; /* packet type */ 56 union { 57 unsigned short tu_block; /* block # */ 58 unsigned short tu_code; /* error code */ 59 char tu_stuff[1]; /* request packet stuff */ 60 } th_u; 61 char th_data[1]; /* data or error string */ 62 }; 63 64 #define th_block th_u.tu_block 65 #define th_code th_u.tu_code 66 #define th_stuff th_u.tu_stuff 67 #define th_msg th_data 68 69 /* 70 * Error codes. 71 */ 72 #define EUNDEF 0 /* not defined */ 73 #define ENOTFOUND 1 /* file not found */ 74 #define EACCESS 2 /* access violation */ 75 #define ENOSPACE 3 /* disk full or allocation exceeded */ 76 #define EBADOP 4 /* illegal TFTP operation */ 77 #define EBADID 5 /* unknown transfer ID */ 78 #define EEXISTS 6 /* file already exists */ 79 #define ENOUSER 7 /* no such user */ 80 81 static const char tstr[] = " [|tftp]"; 82 83 /* op code to string mapping */ 84 static const struct tok op2str[] = { 85 { RRQ, "RRQ" }, /* read request */ 86 { WRQ, "WRQ" }, /* write request */ 87 { DATA, "DATA" }, /* data packet */ 88 { ACK, "ACK" }, /* acknowledgement */ 89 { TFTP_ERROR, "ERROR" }, /* error code */ 90 { OACK, "OACK" }, /* option acknowledgement */ 91 { 0, NULL } 92 }; 93 94 /* error code to string mapping */ 95 static const struct tok err2str[] = { 96 { EUNDEF, "EUNDEF" }, /* not defined */ 97 { ENOTFOUND, "ENOTFOUND" }, /* file not found */ 98 { EACCESS, "EACCESS" }, /* access violation */ 99 { ENOSPACE, "ENOSPACE" }, /* disk full or allocation exceeded */ 100 { EBADOP, "EBADOP" }, /* illegal TFTP operation */ 101 { EBADID, "EBADID" }, /* unknown transfer ID */ 102 { EEXISTS, "EEXISTS" }, /* file already exists */ 103 { ENOUSER, "ENOUSER" }, /* no such user */ 104 { 0, NULL } 105 }; 106 107 /* 108 * Print trivial file transfer program requests 109 */ 110 void 111 tftp_print(netdissect_options *ndo, 112 register const u_char *bp, u_int length) 113 { 114 register const struct tftphdr *tp; 115 register const char *cp; 116 register const u_char *p; 117 register int opcode, i; 118 119 tp = (const struct tftphdr *)bp; 120 121 /* Print length */ 122 ND_PRINT((ndo, " %d", length)); 123 124 /* Print tftp request type */ 125 ND_TCHECK(tp->th_opcode); 126 opcode = EXTRACT_16BITS(&tp->th_opcode); 127 cp = tok2str(op2str, "tftp-#%d", opcode); 128 ND_PRINT((ndo, " %s", cp)); 129 /* Bail if bogus opcode */ 130 if (*cp == 't') 131 return; 132 133 switch (opcode) { 134 135 case RRQ: 136 case WRQ: 137 case OACK: 138 p = (const u_char *)tp->th_stuff; 139 ND_PRINT((ndo, " ")); 140 /* Print filename or first option */ 141 if (opcode != OACK) 142 ND_PRINT((ndo, "\"")); 143 i = fn_print(ndo, p, ndo->ndo_snapend); 144 if (opcode != OACK) 145 ND_PRINT((ndo, "\"")); 146 147 /* Print the mode (RRQ and WRQ only) and any options */ 148 while ((p = (const u_char *)strchr((const char *)p, '\0')) != NULL) { 149 if (length <= (u_int)(p - (const u_char *)&tp->th_block)) 150 break; 151 p++; 152 if (*p != '\0') { 153 ND_PRINT((ndo, " ")); 154 fn_print(ndo, p, ndo->ndo_snapend); 155 } 156 } 157 158 if (i) 159 goto trunc; 160 break; 161 162 case ACK: 163 case DATA: 164 ND_TCHECK(tp->th_block); 165 ND_PRINT((ndo, " block %d", EXTRACT_16BITS(&tp->th_block))); 166 break; 167 168 case TFTP_ERROR: 169 /* Print error code string */ 170 ND_TCHECK(tp->th_code); 171 ND_PRINT((ndo, " %s \"", tok2str(err2str, "tftp-err-#%d \"", 172 EXTRACT_16BITS(&tp->th_code)))); 173 /* Print error message string */ 174 i = fn_print(ndo, (const u_char *)tp->th_data, ndo->ndo_snapend); 175 ND_PRINT((ndo, "\"")); 176 if (i) 177 goto trunc; 178 break; 179 180 default: 181 /* We shouldn't get here */ 182 ND_PRINT((ndo, "(unknown #%d)", opcode)); 183 break; 184 } 185 return; 186 trunc: 187 ND_PRINT((ndo, "%s", tstr)); 188 return; 189 } 190