The Tcpdump Group git mirrors - tcpdump/blob - 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 #ifndef lint
  25 static const char rcsid[] _U_ =
  26     "@(#) $Header: /tcpdump/master/tcpdump/print-tftp.c,v 1.39 2008-04-11 16:47:38 gianluca Exp $ (LBL)";
  27 #endif
  28
  29 #ifdef HAVE_CONFIG_H
  30 #include "config.h"
  31 #endif
  32
  33 #include <tcpdump-stdinc.h>
  34
  35 #ifdef SEGSIZE
  36 #undef SEGSIZE                                  /* SINIX sucks */
  37 #endif
  38
  39 #include <stdio.h>
  40 #include <string.h>
  41
  42 #include "interface.h"
  43 #include "addrtoname.h"
  44 #include "extract.h"
  45
  46 /*
  47  * Trivial File Transfer Protocol (IEN-133)
  48  */
  49 #define SEGSIZE         512             /* data segment size */
  50
  51 /*
  52  * Packet types.
  53  */
  54 #define RRQ     01                      /* read request */
  55 #define WRQ     02                      /* write request */
  56 #define DATA    03                      /* data packet */
  57 #define ACK     04                      /* acknowledgement */
  58 #define TFTP_ERROR      05                      /* error code */
  59 #define OACK    06                      /* option acknowledgement */
  60
  61 struct  tftphdr {
  62         unsigned short  th_opcode;              /* packet type */
  63         union {
  64                 unsigned short  tu_block;       /* block # */
  65                 unsigned short  tu_code;        /* error code */
  66                 char    tu_stuff[1];    /* request packet stuff */
  67         } th_u;
  68         char    th_data[1];             /* data or error string */
  69 };
  70
  71 #define th_block        th_u.tu_block
  72 #define th_code         th_u.tu_code
  73 #define th_stuff        th_u.tu_stuff
  74 #define th_msg          th_data
  75
  76 /*
  77  * Error codes.
  78  */
  79 #define EUNDEF          0               /* not defined */
  80 #define ENOTFOUND       1               /* file not found */
  81 #define EACCESS         2               /* access violation */
  82 #define ENOSPACE        3               /* disk full or allocation exceeded */
  83 #define EBADOP          4               /* illegal TFTP operation */
  84 #define EBADID          5               /* unknown transfer ID */
  85 #define EEXISTS         6               /* file already exists */
  86 #define ENOUSER         7               /* no such user */
  87
  88 static const char tstr[] = " [|tftp]";
  89
  90 /* op code to string mapping */
  91 static const struct tok op2str[] = {
  92         { RRQ,          "RRQ" },        /* read request */
  93         { WRQ,          "WRQ" },        /* write request */
  94         { DATA,         "DATA" },       /* data packet */
  95         { ACK,          "ACK" },        /* acknowledgement */
  96         { TFTP_ERROR,   "ERROR" },      /* error code */
  97         { OACK,         "OACK" },       /* option acknowledgement */
  98         { 0,            NULL }
  99 };
 100
 101 /* error code to string mapping */
 102 static const struct tok err2str[] = {
 103         { EUNDEF,       "EUNDEF" },     /* not defined */
 104         { ENOTFOUND,    "ENOTFOUND" },  /* file not found */
 105         { EACCESS,      "EACCESS" },    /* access violation */
 106         { ENOSPACE,     "ENOSPACE" },   /* disk full or allocation exceeded */
 107         { EBADOP,       "EBADOP" },     /* illegal TFTP operation */
 108         { EBADID,       "EBADID" },     /* unknown transfer ID */
 109         { EEXISTS,      "EEXISTS" },    /* file already exists */
 110         { ENOUSER,      "ENOUSER" },    /* no such user */
 111         { 0,            NULL }
 112 };
 113
 114 /*
 115  * Print trivial file transfer program requests
 116  */
 117 void
 118 tftp_print(register const u_char *bp, u_int length)
 119 {
 120         register const struct tftphdr *tp;
 121         register const char *cp;
 122         register const u_char *p;
 123         register int opcode, i;
 124
 125         tp = (const struct tftphdr *)bp;
 126
 127         /* Print length */
 128         printf(" %d", length);
 129
 130         /* Print tftp request type */
 131         TCHECK(tp->th_opcode);
 132         opcode = EXTRACT_16BITS(&tp->th_opcode);
 133         cp = tok2str(op2str, "tftp-#%d", opcode);
 134         printf(" %s", cp);
 135         /* Bail if bogus opcode */
 136         if (*cp == 't')
 137                 return;
 138
 139         switch (opcode) {
 140
 141         case RRQ:
 142         case WRQ:
 143         case OACK:
 144                 p = (u_char *)tp->th_stuff;
 145                 putchar(' ');
 146                 /* Print filename or first option */
 147                 if (opcode != OACK)
 148                         putchar('"');
 149                 i = fn_print(p, snapend);
 150                 if (opcode != OACK)
 151                         putchar('"');
 152
 153                 /* Print the mode (RRQ and WRQ only) and any options */
 154                 while ((p = (const u_char *)strchr((const char *)p, '\0')) != NULL) {
 155                         if (length <= (u_int)(p - (const u_char *)&tp->th_block))
 156                                 break;
 157                         p++;
 158                         if (*p != '\0') {
 159                                 putchar(' ');
 160                                 fn_print(p, snapend);
 161                         }
 162                 }
 163
 164                 if (i)
 165                         goto trunc;
 166                 break;
 167
 168         case ACK:
 169         case DATA:
 170                 TCHECK(tp->th_block);
 171                 printf(" block %d", EXTRACT_16BITS(&tp->th_block));
 172                 break;
 173
 174         case TFTP_ERROR:
 175                 /* Print error code string */
 176                 TCHECK(tp->th_code);
 177                 printf(" %s \"", tok2str(err2str, "tftp-err-#%d \"",
 178                                        EXTRACT_16BITS(&tp->th_code)));
 179                 /* Print error message string */
 180                 i = fn_print((const u_char *)tp->th_data, snapend);
 181                 putchar('"');
 182                 if (i)
 183                         goto trunc;
 184                 break;
 185
 186         default:
 187                 /* We shouldn't get here */
 188                 printf("(unknown #%d)", opcode);
 189                 break;
 190         }
 191         return;
 192 trunc:
 193         fputs(tstr, stdout);
 194         return;
 195 }