8 on the receiving side. Please note that a block whose size is less than the block size indicates
11 To indicate the end of a transfer where the content is aligned with the block size, an additional  
18 Real file transaction is started using the functions pico$\_$tftp$\_$start$\_$tx and pico$\_$tftp$\_$start$\_$rx; both require a callback that must be provided by the user to handle single chunks of the transmission. The transmitter callback must use pico$\_$tftp$\_$send function to send each block of data.
20 In case of problem the session can be aborted (and an error message is sent to the remote side) using pico$\_$tftp$\_$abort.
22 When a transfer is complete the session became invalid and must not be used any more.
26 In some use case is preferable to have an application driven behaviour. The API provide 5 specific functions to use TFTP in this scenario.
28 The way to obtain a session handler suited for this purpose is an invocation to the function pico$\_$tftp$\_$app$\_$setup. The synchro variable passed to this function will play a key role during the management of the transfer.
32 Once the session is created, the application can start receiving a file with a call to the function pico$\_$tftp$\_$app$\_$start$\_$rx or, if needs to transmit, invoking  pico$\_$tftp$\_$app$\_$start$\_$tx.
34 After the file transfer is started the user is allowed to perform data handling only when the synchro variable associated with the session is not 0. It is set to 0 after calling pico$\_$tftp$\_$app$\_$setup. A value that differ to 0 means that a single chunk is ready to be handled.
38 Once the file transfer ends, both for completion or in case of error, the session is no more valid.
66 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
103 This message is used in listen callback to reject a request with an error message.
131 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
204 In case of success a session handler is returned. In case of failure, NULL is returned and pico$\_$err is set accordingly.
226 This function is used to require the use of Extended Options for TFTP transfer associate to a session according to RFC 2347 and RFC 2349. It should be used before the invocation of pico$\_$tftp$\_$start$\_$rx or pico$\_$tftp$\_$start$\_$tx unless the setting is related to the timeout.
228 To require to adopt a specific fixed value for the timeout PICO$\_$TFTP$\_$OPTION$\_$TIME must be used with a value ranging between 1 and 255. If this option is set to a value of 0 (or not used at all) an adaptive timeout algorithm will take care of the retransmissions.
244 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
263 This function is used to retrieve the values of Extended Options that has been set to a session according to RFC 2347 and RFC 2349.
265 To query the timeout PICO$\_$TFTP$\_$OPTION$\_$TIME must be used; a value ranging between 1 and 255 will be returned in the value parameter if the fixed interval is in place. If the call return -1 and pico$\_$err is set to PICO$\_$ERR$\_$ENOENT the adaptive timeout algorithm is running.
281 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
294             printf("TFTP: Option filesize is not used\n");
309 This function is used to extract Extension Options eventually present in Read or Write request (in the listen callback) or in Option ACKnowledge messages (in transmitter or receiver callback when event is equal to PICO$\_$TFTP$\_$EV$\_$OPT).
310 Note that timeout and filesize are modified only if the corresponding option is found in the received message.
328 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
411 \item \texttt{arg} - The pointer is sent as argument to the callback.
415 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
435 Send the next block during an active TFTP transfer. This is ideally called every time the user callback is triggered by the protocol, indicating that the transfer of the last block has been acknowledged. The user should not call this function unless it's solicited by the protocol during an active transmit session.
447 \item \texttt{len} - the size of the buffer being transmitted. If $<$ \texttt{BLOCKSIZE}, the transfer is concluded. In order to terminate a transfer where the content is aligned to \texttt{BLOCKSIZE}, a zero-sized \texttt{pico$\_$tftp$\_$send} must be called at the end of the transfer.
451 In case of success, the number of bytes transmitted is returned. In case of failure, -1 is returned and pico$\_$err is set accordingly.
521 \item \texttt{user$\_$cb} - The callback provided by the user to be called upon each block transfer, option acknowledge or in case of error. This is the callback where the incoming data is processed. When len is less than the block size, the transfer is over.
526 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
547 This function is used to retrieve the file size (if transmitted by the remote or set as session option). It is equivalent to a call to pico$\_$tftp$\_$get$\_$option(session, PICO$\_$TFTP$\_$OPTION$\_$FILE, $\&$file$\_$size);
562 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
574 When called this function aborts associated ongoing transmission and notifying the other endpoint with a proper error message. After a call to this function the session is closed automatically.
602 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
645 This function is used to shutdown the TFTP server.
653 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
683 In case of success a session handler is returned. In case of failure, NULL is returned and pico$\_$err is set accordingly.
714 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
754 This function returns 0 if succeeds or -1 in case of errors (pico$\_$err is set accordingly).
785 Read the next block during an active TFTP transfer. The len field must always be equal to PICO$\_$TFTP$\_$PAYLOAD$\_$SIZE. Once the file has been sent or after an error the session is no more valid.
797 \item \texttt{len} - Length of the buffer size to receive; it is equal to the fixed chunk size.
801 This function returns the number of received bytes of payload (0 included) if succeeds. In case of error a negative number is returned.
850 Send the next block during an active TFTP transfer. The len field, with the exception of last invocation must always be equal to PICO$\_$TFTP$\_$PAYLOAD$\_$SIZE. Once the file has been sent or after an error the session is no more valid.
867 This function returns the number of transmitted payload data (len) if succeeds. In case of error a negative number is returned.

Indexes created Mon Jul 15 19:46:26 MDT 2024