_tftp.c

This directory contains source code for tcpdump, a tool for network monitoring and data acquisition

/*
 * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Format and print trivial file transfer protocol packets.
 */

#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/tftp.h>

#include "interfac.h"
#include "a2name.h"

/* op code to string mapping
 */
static struct tok op2str[] = {
  { RRQ,  "RRQ"   },            /* read request */
  { WRQ,  "WRQ"   },            /* write request */
  { DATA, "DATA"  },            /* data packet */
  { ACK,  "ACK"   },            /* acknowledgement */
  { ERROR,"ERROR" },            /* error code */
  { 0,    NULL    }
};

/* error code to string mapping
 */
static struct tok err2str[] = {
  { EUNDEF,    "EUNDEF"    },   /* not defined */
  { ENOTFOUND, "ENOTFOUND" },   /* file not found */
  { EACCESS,   "EACCESS"   },   /* access violation */
  { ENOSPACE,  "ENOSPACE"  },   /* disk full or allocation exceeded */
  { EBADOP,    "EBADOP"    },   /* illegal TFTP operation */
  { EBADID,    "EBADID"    },   /* unknown transfer ID */
  { EEXISTS,   "EEXISTS"   },   /* file already exists */
  { ENOUSER,   "ENOUSER"   },   /* no such user */
  { 0,         NULL        }
};

/* 
 * Print trivial file transfer program requests
 */
void tftp_print (const u_char * bp, u_int length)
{
  const  struct tftphdr *tp;
  const  char *cp;
  const  u_char *p;
  int    opcode, i;
  static char tstr[] = " [|tftp]";

  tp = (const struct tftphdr *) bp;

  /* Print length */
  PRINTF (" %d", length);

  /* Print tftp request type */
  TCHECK (tp->th_opcode);
  opcode = ntohs (tp->th_opcode);
  cp = tok2str (op2str, "tftp-#%d", opcode);
  PUTCHAR (' ');
  PUTS (cp);

  /* Bail if bogus opcode */
  if (*cp == 't')
     return;

  switch (opcode)
  {
    case RRQ:
    case WRQ:
         /*
          * XXX Not all arpa/tftp.h's specify th_stuff as any
          * array; use address of th_block instead
          */
         p = (u_char *) & tp->th_block;
         PUTS (" \"");
         i = fn_print ((char *) p, (char *) snapend);
         PUTCHAR ('"');
         if (i)
           goto trunc;
         break;

    case ACK:
    case DATA:
         TCHECK (tp->th_block);
         PRINTF (" block %d", ntohs (tp->th_block));
         break;

    case ERROR:
         /* Print error code string */
         TCHECK (tp->th_code);
         PRINTF (" %s ", tok2str (err2str, "tftp-err-#%d \"",
                                  ntohs (tp->th_code)));
         /* Print error message string */
         i = fn_print ((char *) tp->th_data, (char *) snapend);
         PUTCHAR ('"');
         if (i)
           goto trunc;
         break;

    default:
         /* We shouldn't get here */
         PRINTF ("(unknown #%d)", opcode);
         break;
  }
  return;

trunc:
  PUTS (tstr);
}