HTTP/1.1 200 OK Date: Tue, 09 Apr 2002 08:43:00 GMT Server: Apache/1.3.20 (Unix) Last-Modified: Tue, 13 Dec 1994 23:00:00 GMT ETag: "323ca0-1872-2eee2770" Accept-Ranges: bytes Content-Length: 6258 Connection: close Content-Type: text/plain draft-ietf-tftpexts-options-00.txt G. Malkin / Xylogics, Inc. TFTP Blocksize Option A. Harkin / Hewlett Packard Co. December 1994 TFTP Timeout Interval and Transfer Size Options Abstract The Trivial File Transfer Protocol [1] is a simple, lock-step, file transfer protocol which allows a client to get or put a file onto a remote host. This document describes two TFTP options. The first allows the client and server to negotiate the Timeout Interval. The second allows the side receiving the file to determine the ultimate size of the transfer before it begins. The TFTP Option Extension mechanism is described in [2]. Status of this Memo This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." To learn the current status of any Internet-Draft, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim). Timeout Interval Option Specification The TFTP Read Request or Write Request packet is modified to include the timeout option as follows: +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+ | opc |filename| 0 | mode | 0 | timeout| 0 | #secs | 0 | +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+ Malkin & Harkin Expires: 8Jun95 [Page 1] Internet Draft TFTP Options December 1994 opc The opcode field contains either a 1, for Read Requests, or 2, for Write Requests, as defined in [1]. filename The name of the file to be read or written, as defined in [1]. This is a NULL-terminated field. mode The mode of the file transfer: "netascii", "octet", or "mail", as defined in [1]. This is a NULL-terminated field. timeout The Timeout Interval option, "timeout" (case in-sensitive). This is a NULL-terminated field. #secs The number of seconds to wait before retransmitting, specified in ASCII. Valid values range between "1" and "255" octets, inclusive. This is a NULL-terminated field. For example: +-------+--------+---+--------+---+--------+---+--------+---+ | 1 | foobar | 0 | binary | 0 | timeout| 0 | 1 | 0 | +-------+--------+---+--------+---+--------+---+--------+---+ is a Read Request, for the file named "foobar", in binary transfer mode, with a timeout interval of 1 second. If the server is willing to accept the timeout option, it sends an Option Acknowledgment (OACK) to the client. The specified timeout value must match the value specified by the client. Transfer Size Option Specification The TFTP Read Request or Write Request packet is modified to include the tsize option as follows: +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+ | opc |filename| 0 | mode | 0 | tsize | 0 | size | 0 | +-------+---~~---+---+---~~---+---+---~~---+---+---~~---+---+ opc The opcode field contains either a 1, for Read Requests, or 2, for Write Requests, as defined in [1]. Malkin & Harkin Expires: 8Jun95 [Page 2] Internet Draft TFTP Options December 1994 filename The name of the file to be read or written, as defined in [1]. This is a NULL-terminated field. mode The mode of the file transfer: "netascii", "octet", or "mail", as defined in [1]. This is a NULL-terminated field. tsize The Transfer Size option, "tsize" (case in-sensitive). This is a NULL-terminated field. size The size of the file to be transfered. This is a NULL- terminated field. For example: +-------+--------+---+--------+---+--------+---+--------+---+ | 2 | foobar | 0 | binary | 0 | tsize | 0 | 673312 | 0 | +-------+--------+---+--------+---+--------+---+--------+---+ is a Write Request, with the 673312-octet file named "foobar", in binary transfer mode. In Read Request packets, a size of "0" is specified in the request and the size of the file, in octets, is returned in the OACK. If the file is too large for the client to handle, it may abort the transfer with an Error packet (error code 3). In Write Request packets, the size of the file, in octets, is specified in the request and echoed back in the OACK. If the file is too large for the server to handle, it may abort the transfer with an Error packet (error code 3). Security Considerations Security issues are not discussed in this memo. References [1] Sollins, K., "The TFTP Protocol (Revision 2)", Request for Comments 1350 (STD 33), October 1992. [2] Malkin, G., Harkin, A., "TFTP Option Extension", Internet Draft, draft-ietf-tftpexts-options-02.txt, December 1994. Malkin & Harkin Expires: 8Jun95 [Page 3] Internet Draft TFTP Options December 1994 Authors' Addresses Gary Scott Malkin Xylogics, Inc. 53 Third Avenue Burlington, MA 01803 Phone: (617) 272-8140 EMail: gmalkin@xylogics.com Art Harkin Internet Services Project Information Networks Division 19420 Homestead Road MS 43LN Cupertino, CA 95014 Phone: (408) 447-3755 EMail: ash@cup.hp.com Malkin & Harkin Expires: 8Jun95 [Page 4]