text: /*
   * Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997
   *	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.
   */
  
  /* \summary: Trivial File Transfer Protocol (TFTP) printer */
  
  #ifdef HAVE_CONFIG_H
  #include <config.h>
  #endif
  
  #include "netdissect-stdinc.h"
  
  #include <string.h>
  
  #include "netdissect.h"
  #include "extract.h"
  
  /*
   * Trivial File Transfer Protocol (IEN-133)
   */
  
  /*
   * Packet types.
   */
  #define	RRQ	01			/* read request */
  #define	WRQ	02			/* write request */
  #define	DATA	03			/* data packet */
  #define	ACK	04			/* acknowledgement */
  #define	TFTP_ERROR	05			/* error code */
  #define OACK	06			/* option acknowledgement */
  
  /*
   * Error codes.
   */
  #define	EUNDEF		0		/* not defined */
  #define	ENOTFOUND	1		/* file not found */
  #define	EACCESS		2		/* access violation */
  #define	ENOSPACE	3		/* disk full or allocation exceeded */
  #define	EBADOP		4		/* illegal TFTP operation */
  #define	EBADID		5		/* unknown transfer ID */
  #define	EEXISTS		6		/* file already exists */
  #define	ENOUSER		7		/* no such user */
  
  static const char tstr[] = " [|tftp]";
  
  /* op code to string mapping */
  static const struct tok op2str[] = {
  	{ RRQ,		"RRQ" },	/* read request */
  	{ WRQ,		"WRQ" },	/* write request */
  	{ DATA,		"DATA" },	/* data packet */
  	{ ACK,		"ACK" },	/* acknowledgement */
  	{ TFTP_ERROR,	"ERROR" },	/* error code */
  	{ OACK,		"OACK" },	/* option acknowledgement */
  	{ 0,		NULL }
  };
  
  /* error code to string mapping */
  static const 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(netdissect_options *ndo,
             const u_char *bp, u_int length)
  {
  	const char *cp;
  	u_int opcode;
  	u_int ui;
  
  	/* Print length */
  	ND_PRINT(" %u", length);
  
  	/* Print tftp request type */
  	if (length < 2)
  		goto trunc;
  	ND_TCHECK_2(bp);
  	opcode = EXTRACT_BE_U_2(bp);
  	cp = tok2str(op2str, "tftp-#%u", opcode);
  	ND_PRINT(" %s", cp);
  	/* Bail if bogus opcode */
  	if (*cp == 't')
  		return;
  	bp += 2;
  	length -= 2;
  
  	switch (opcode) {
  
  	case RRQ:
  	case WRQ:
  		if (length == 0)
  			goto trunc;
  		ND_PRINT(" ");
  		/* Print filename */
  		ND_PRINT("\"");
  		ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
  		ND_PRINT("\"");
  		if (ui == 0)
  			goto trunc;
  		bp += ui;
  		length -= ui;
  
  		/* Print the mode - RRQ and WRQ only */
  		if (length == 0)
  			goto trunc;	/* no mode */
  		ND_PRINT(" ");
  		ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
  		if (ui == 0)
  			goto trunc;
  		bp += ui;
  		length -= ui;
  
  		/* Print options, if any */
  		while (length != 0) {
  			ND_TCHECK_1(bp);
  			if (EXTRACT_U_1(bp) != '\0')
  				ND_PRINT(" ");
  			ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
  			if (ui == 0)
  				goto trunc;
  			bp += ui;
  			length -= ui;
  		}
  		break;
  
  	case OACK:
  		/* Print options */
  		while (length != 0) {
  			ND_TCHECK_1(bp);
  			if (EXTRACT_U_1(bp) != '\0')
  				ND_PRINT(" ");
  			ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
  			if (ui == 0)
  				goto trunc;
  			bp += ui;
  			length -= ui;
  		}
  		break;
  
  	case ACK:
  	case DATA:
  		if (length < 2)
  			goto trunc;	/* no block number */
  		ND_TCHECK_2(bp);
  		ND_PRINT(" block %u", EXTRACT_BE_U_2(bp));
  		break;
  
  	case TFTP_ERROR:
  		/* Print error code string */
  		if (length < 2)
  			goto trunc;	/* no error code */
  		ND_TCHECK_2(bp);
  		ND_PRINT(" %s", tok2str(err2str, "tftp-err-#%u \"",
  				       EXTRACT_BE_U_2(bp)));
  		bp += 2;
  		length -= 2;
  		/* Print error message string */
  		if (length == 0)
  			goto trunc;	/* no error message */
  		ND_PRINT(" \"");
  		ui = fn_printztn(ndo, bp, length, ndo->ndo_snapend);
  		ND_PRINT("\"");
  		if (ui == 0)
  			goto trunc;
  		break;
  
  	default:
  		/* We shouldn't get here */
  		ND_PRINT("(unknown #%u)", opcode);
  		break;
  	}
  	return;
  trunc:
  	ND_PRINT("%s", tstr);
  	return;
  }
  