* Copyright (c) 1990, 1991, 1993, 1994, 1995, 1996, 1997

/*
* 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 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: print-tftp.c,v 1.10 2024/09/02 16:15:33 christos Exp $");
#endif

#include <config.h>

#include "netdissect-stdinc.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 */

/* 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;

ndo->ndo_protocol = "tftp";

/* Print protocol */
nd_print_protocol_caps(ndo);
/* Print length */
ND_PRINT(", length %u", length);

/* Print tftp request type */
if (length < 2)
goto trunc;
opcode = GET_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 = nd_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 = nd_printztn(ndo, bp, length, ndo->ndo_snapend);
if (ui == 0)
goto trunc;
bp += ui;
length -= ui;

/* Print options, if any */
while (length != 0) {
if (GET_U_1(bp) != '\0')
ND_PRINT(" ");
ui = nd_printztn(ndo, bp, length, ndo->ndo_snapend);
if (ui == 0)
goto trunc;
bp += ui;
length -= ui;
}
break;

case OACK:
/* Print options */
while (length != 0) {
if (GET_U_1(bp) != '\0')
ND_PRINT(" ");
ui = nd_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_PRINT(" block %u", GET_BE_U_2(bp));
break;

case TFTP_ERROR:
/* Print error code string */
if (length < 2)
goto trunc; /* no error code */
ND_PRINT(" %s", tok2str(err2str, "tftp-err-#%u \"",
GET_BE_U_2(bp)));
bp += 2;
length -= 2;
/* Print error message string */
if (length == 0)
goto trunc; /* no error message */
ND_PRINT(" \"");
ui = nd_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_trunc(ndo);
}