external/bsd/tcpdump/dist/print-tftp.c

   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 1.5 2014/11/20 03:05:03 christos Exp $");
  27 #endif
  28
  29 #define NETDISSECT_REWORKED
  30 #ifdef HAVE_CONFIG_H
  31 #include "config.h"
  32 #endif
  33
  34 #include <tcpdump-stdinc.h>
  35
  36 #include <string.h>
  37
  38 #include "interface.h"
  39 #include "extract.h"
  40
  41 /*
  42  * Trivial File Transfer Protocol (IEN-133)
  43  */
  44
  45 /*
  46  * Packet types.
  47  */
  48 #define RRQ     01                      /* read request */
  49 #define WRQ     02                      /* write request */
  50 #define DATA    03                      /* data packet */
  51 #define ACK     04                      /* acknowledgement */
  52 #define TFTP_ERROR      05                      /* error code */
  53 #define OACK    06                      /* option acknowledgement */
  54
  55 struct  tftphdr {
  56         unsigned short  th_opcode;              /* packet type */
  57         union {
  58                 unsigned short  tu_block;       /* block # */
  59                 unsigned short  tu_code;        /* error code */
  60                 char    tu_stuff[1];    /* request packet stuff */
  61         } th_u;
  62         char    th_data[1];             /* data or error string */
  63 };
  64
  65 #define th_block        th_u.tu_block
  66 #define th_code         th_u.tu_code
  67 #define th_stuff        th_u.tu_stuff
  68 #define th_msg          th_data
  69
  70 /*
  71  * Error codes.
  72  */
  73 #define EUNDEF          0               /* not defined */
  74 #define ENOTFOUND       1               /* file not found */
  75 #define EACCESS         2               /* access violation */
  76 #define ENOSPACE        3               /* disk full or allocation exceeded */
  77 #define EBADOP          4               /* illegal TFTP operation */
  78 #define EBADID          5               /* unknown transfer ID */
  79 #define EEXISTS         6               /* file already exists */
  80 #define ENOUSER         7               /* no such user */
  81
  82 static const char tstr[] = " [|tftp]";
  83
  84 /* op code to string mapping */
  85 static const struct tok op2str[] = {
  86         { RRQ,          "RRQ" },        /* read request */
  87         { WRQ,          "WRQ" },        /* write request */
  88         { DATA,         "DATA" },       /* data packet */
  89         { ACK,          "ACK" },        /* acknowledgement */
  90         { TFTP_ERROR,   "ERROR" },      /* error code */
  91         { OACK,         "OACK" },       /* option acknowledgement */
  92         { 0,            NULL }
  93 };
  94
  95 /* error code to string mapping */
  96 static const struct tok err2str[] = {
  97         { EUNDEF,       "EUNDEF" },     /* not defined */
  98         { ENOTFOUND,    "ENOTFOUND" },  /* file not found */
  99         { EACCESS,      "EACCESS" },    /* access violation */
 100         { ENOSPACE,     "ENOSPACE" },   /* disk full or allocation exceeded */
 101         { EBADOP,       "EBADOP" },     /* illegal TFTP operation */
 102         { EBADID,       "EBADID" },     /* unknown transfer ID */
 103         { EEXISTS,      "EEXISTS" },    /* file already exists */
 104         { ENOUSER,      "ENOUSER" },    /* no such user */
 105         { 0,            NULL }
 106 };
 107
 108 /*
 109  * Print trivial file transfer program requests
 110  */
 111 void
 112 tftp_print(netdissect_options *ndo,
 113            register const u_char *bp, u_int length)
 114 {
 115         register const struct tftphdr *tp;
 116         register const char *cp;
 117         register const u_char *p;
 118         register int opcode, i;
 119
 120         tp = (const struct tftphdr *)bp;
 121
 122         /* Print length */
 123         ND_PRINT((ndo, " %d", length));
 124
 125         /* Print tftp request type */
 126         ND_TCHECK(tp->th_opcode);
 127         opcode = EXTRACT_16BITS(&tp->th_opcode);
 128         cp = tok2str(op2str, "tftp-#%d", opcode);
 129         ND_PRINT((ndo, " %s", cp));
 130         /* Bail if bogus opcode */
 131         if (*cp == 't')
 132                 return;
 133
 134         switch (opcode) {
 135
 136         case RRQ:
 137         case WRQ:
 138         case OACK:
 139                 p = (u_char *)tp->th_stuff;
 140                 ND_PRINT((ndo, " "));
 141                 /* Print filename or first option */
 142                 if (opcode != OACK)
 143                         ND_PRINT((ndo, "\""));
 144                 i = fn_print(ndo, p, ndo->ndo_snapend);
 145                 if (opcode != OACK)
 146                         ND_PRINT((ndo, "\""));
 147
 148                 /* Print the mode (RRQ and WRQ only) and any options */
 149                 while ((p = (const u_char *)strchr((const char *)p, '\0')) != NULL) {
 150                         if (length <= (u_int)(p - (const u_char *)&tp->th_block))
 151                                 break;
 152                         p++;
 153                         if (*p != '\0') {
 154                                 ND_PRINT((ndo, " "));
 155                                 fn_print(ndo, p, ndo->ndo_snapend);
 156                         }
 157                 }
 158
 159                 if (i)
 160                         goto trunc;
 161                 break;
 162
 163         case ACK:
 164         case DATA:
 165                 ND_TCHECK(tp->th_block);
 166                 ND_PRINT((ndo, " block %d", EXTRACT_16BITS(&tp->th_block)));
 167                 break;
 168
 169         case TFTP_ERROR:
 170                 /* Print error code string */
 171                 ND_TCHECK(tp->th_code);
 172                 ND_PRINT((ndo, " %s \"", tok2str(err2str, "tftp-err-#%d \"",
 173                                        EXTRACT_16BITS(&tp->th_code))));
 174                 /* Print error message string */
 175                 i = fn_print(ndo, (const u_char *)tp->th_data, ndo->ndo_snapend);
 176                 ND_PRINT((ndo, "\""));
 177                 if (i)
 178                         goto trunc;
 179                 break;
 180
 181         default:
 182                 /* We shouldn't get here */
 183                 ND_PRINT((ndo, "(unknown #%d)", opcode));
 184                 break;
 185         }
 186         return;
 187 trunc:
 188         ND_PRINT((ndo, "%s", tstr));
 189         return;
 190 }