
Now sending all packets to the progresshook, not just DAT packets, so that the client can see the OACK. Not yet making use of the returned tsize. Need to test this on a server that supports tsize.
283 lines
7.7 KiB
Text
283 lines
7.7 KiB
Text
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Network Working Group G. Malkin
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Request for Commments: 2349 Bay Networks
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Updates: 1350 A. Harkin
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Obsoletes: 1784 Hewlett Packard Co.
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Category: Standards Track May 1998
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TFTP Timeout Interval and Transfer Size Options
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Status of this Memo
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This document specifies an Internet standards track protocol for the
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Internet community, and requests discussion and suggestions for
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improvements. Please refer to the current edition of the "Internet
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Official Protocol Standards" (STD 1) for the standardization state
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and status of this protocol. Distribution of this memo is unlimited.
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Copyright Notice
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Copyright (C) The Internet Society (1998). All Rights Reserved.
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Abstract
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The Trivial File Transfer Protocol [1] is a simple, lock-step, file
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transfer protocol which allows a client to get or put a file onto a
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remote host.
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This document describes two TFTP options. The first allows the client
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and server to negotiate the Timeout Interval. The second allows the
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side receiving the file to determine the ultimate size of the
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transfer before it begins. The TFTP Option Extension mechanism is
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described in [2].
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Timeout Interval Option Specification
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The TFTP Read Request or Write Request packet is modified to include
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the timeout option as follows:
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+-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
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| opc |filename| 0 | mode | 0 | timeout| 0 | #secs | 0 |
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+-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
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opc
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The opcode field contains either a 1, for Read Requests, or 2,
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for Write Requests, as defined in [1].
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Malkin & Harkin Standards Track [Page 1]
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RFC 2349 TFTP Timeout Interval and Transfer Size Options May 1998
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filename
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The name of the file to be read or written, as defined in [1].
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This is a NULL-terminated field.
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mode
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The mode of the file transfer: "netascii", "octet", or "mail",
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as defined in [1]. This is a NULL-terminated field.
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timeout
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The Timeout Interval option, "timeout" (case in-sensitive).
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This is a NULL-terminated field.
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#secs
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The number of seconds to wait before retransmitting, specified
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in ASCII. Valid values range between "1" and "255" seconds,
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inclusive. This is a NULL-terminated field.
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For example:
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+-------+--------+---+--------+---+--------+---+-------+---+
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| 1 | foobar | 0 | octet | 0 | timeout| 0 | 1 | 0 |
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+-------+--------+---+--------+---+--------+---+-------+---+
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is a Read Request, for the file named "foobar", in octet (binary)
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transfer mode, with a timeout interval of 1 second.
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If the server is willing to accept the timeout option, it sends an
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Option Acknowledgment (OACK) to the client. The specified timeout
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value must match the value specified by the client.
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Transfer Size Option Specification
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The TFTP Read Request or Write Request packet is modified to include
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the tsize option as follows:
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+-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
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| opc |filename| 0 | mode | 0 | tsize | 0 | size | 0 |
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+-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+
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opc
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The opcode field contains either a 1, for Read Requests, or 2,
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for Write Requests, as defined in [1].
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filename
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The name of the file to be read or written, as defined in [1].
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This is a NULL-terminated field.
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Malkin & Harkin Standards Track [Page 2]
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RFC 2349 TFTP Timeout Interval and Transfer Size Options May 1998
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mode
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The mode of the file transfer: "netascii", "octet", or "mail",
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as defined in [1]. This is a NULL-terminated field.
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tsize
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The Transfer Size option, "tsize" (case in-sensitive). This is
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a NULL-terminated field.
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size
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The size of the file to be transfered. This is a NULL-
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terminated field.
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For example:
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+-------+--------+---+--------+---+--------+---+--------+---+
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| 2 | foobar | 0 | octet | 0 | tsize | 0 | 673312 | 0 |
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+-------+--------+---+--------+---+--------+---+--------+---+
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is a Write Request, with the 673312-octet file named "foobar", in
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octet (binary) transfer mode.
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In Read Request packets, a size of "0" is specified in the request
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and the size of the file, in octets, is returned in the OACK. If the
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file is too large for the client to handle, it may abort the transfer
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with an Error packet (error code 3). In Write Request packets, the
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size of the file, in octets, is specified in the request and echoed
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back in the OACK. If the file is too large for the server to handle,
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it may abort the transfer with an Error packet (error code 3).
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Security Considerations
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The basic TFTP protocol has no security mechanism. This is why it
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has no rename, delete, or file overwrite capabilities. This document
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does not add any security to TFTP; however, the specified extensions
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do not add any additional security risks.
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References
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[1] Sollins, K., "The TFTP Protocol (Revision 2)", STD 33, RFC 1350,
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October 92.
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[2] Malkin, G., and A. Harkin, "TFTP Option Extension", RFC 2347,
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May 1998.
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Malkin & Harkin Standards Track [Page 3]
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RFC 2349 TFTP Timeout Interval and Transfer Size Options May 1998
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Authors' Addresses
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Gary Scott Malkin
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Bay Networks
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8 Federal Street
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Billerica, MA 01821
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Phone: (978) 916-4237
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EMail: gmalkin@baynetworks.com
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Art Harkin
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Internet Services Project
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Information Networks Division
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19420 Homestead Road MS 43LN
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Cupertino, CA 95014
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Phone: (408) 447-3755
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EMail: ash@cup.hp.com
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Malkin & Harkin Standards Track [Page 4]
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RFC 2349 TFTP Timeout Interval and Transfer Size Options May 1998
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Full Copyright Statement
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||
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Copyright (C) The Internet Society (1998). All Rights Reserved.
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||
This document and translations of it may be copied and furnished to
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||
others, and derivative works that comment on or otherwise explain it
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||
or assist in its implementation may be prepared, copied, published
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||
and distributed, in whole or in part, without restriction of any
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||
kind, provided that the above copyright notice and this paragraph are
|
||
included on all such copies and derivative works. However, this
|
||
document itself may not be modified in any way, such as by removing
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||
the copyright notice or references to the Internet Society or other
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Internet organizations, except as needed for the purpose of
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||
developing Internet standards in which case the procedures for
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||
copyrights defined in the Internet Standards process must be
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||
followed, or as required to translate it into languages other than
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English.
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||
|
||
The limited permissions granted above are perpetual and will not be
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||
revoked by the Internet Society or its successors or assigns.
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||
|
||
This document and the information contained herein is provided on an
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||
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
|
||
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
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||
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
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||
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
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||
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
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Malkin & Harkin Standards Track [Page 5]
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