/* Check if the received acknowledgement is correct */
u32_t tftp_is_correct_ack(char *buf, int block)
{
/* first make sure this is a data ACK packet */
if (tftp_decode_op(buf) != TFTP_ACK)
return 0;
/* then compare block numbers */
if (block != tftp_extract_block(buf))
return 0;
return 1;
}
/**
* @brief receive callback during tftp write operation (not on standard port 69)
* @param arg: pointer on argument passed to callback
* @param udp_pcb: pointer on the udp pcb
* @param pkt_buf: pointer on the received pbuf
* @param addr: pointer on remote IP address
* @param port: pointer on remote port
* @retval None
*/
void wrq_recv_callback(void *arg, struct udp_pcb *upcb, struct pbuf *pkt_buf, struct ip_addr *addr, u16_t port)
{
tftp_connection_args *args = (tftp_connection_args *)arg;
int n = 0;
/* we expect to receive only one pbuf (pbuf size should be
configured > max TFTP frame size */
if (pkt_buf->len != pkt_buf->tot_len)
{
return;
}
/* Does this packet have any valid data to write? */
if ((pkt_buf->len > TFTP_DATA_PKT_HDR_LEN) &&
(tftp_extract_block(pkt_buf->payload) == (args->block + 1)))
{
/* write the received data to the file */
memcpy((char*)TempBuffer, (char*)pkt_buf->payload + TFTP_DATA_PKT_HDR_LEN, pkt_buf->len - TFTP_DATA_PKT_HDR_LEN);
f_write(&file_CR, (char*)TempBuffer, pkt_buf->len - TFTP_DATA_PKT_HDR_LEN, (UINT*)&n);
if (n <= 0)
{
tftp_send_error_message(upcb, addr, port, TFTP_ERR_FILE_NOT_FOUND);
/* close the connection */
tftp_cleanup_wr(upcb, args); /* close the connection */
}
/* update our block number to match the block number just received */
args->block++;
/* update total bytes */
(args->tot_bytes) += (pkt_buf->len - TFTP_DATA_PKT_HDR_LEN);
}
else if (tftp_extract_block(pkt_buf->payload) == (args->block + 1))
{
/* update our block number to match the block number just received */
args->block++;
}
/* Send the appropriate ACK pkt (the block number sent in the ACK pkt echoes
* the block number of the DATA pkt we just received - see RFC1350)
* NOTE!: If the DATA pkt we received did not have the appropriate block
* number, then the args->block (our block number) is never updated and
* we simply send "duplicate ACK" which has the same block number as the
* last ACK pkt we sent. This lets the host know that we are still waiting
* on block number args->block+1.
*/
tftp_send_ack_packet(upcb, addr, port, args->block);
/* If the last write returned less than the maximum TFTP data pkt length,
* then we've received the whole file and so we can quit (this is how TFTP
* signals the end of a transfer!)
*/
if (pkt_buf->len < TFTP_DATA_PKT_LEN_MAX)
{
tftp_cleanup_wr(upcb, args);
pbuf_free(pkt_buf);
}
else
{
pbuf_free(pkt_buf);
return;
}
}
void wrq_recv_callback(void *_args, struct udp_pcb *upcb, struct pbuf *pkt_buf, struct ip_addr *addr, u16_t port)
{
tftp_connection_args *args = (tftp_connection_args *)_args;
int n = 0;
if (pkt_buf->len != pkt_buf->tot_len)
{
return;
}
/* Does this packet have any valid data to write? */
if ((pkt_buf->len > TFTP_DATA_PKT_HDR_LEN) &&
(tftp_extract_block(pkt_buf->payload) == (args->block + 1)))
{
/* write the received data to the file */
n = file_write(&file_CR,
pkt_buf->len - TFTP_DATA_PKT_HDR_LEN,
(euint8*)pkt_buf->payload + TFTP_DATA_PKT_HDR_LEN);
if (n <= 0)
{
tftp_send_error_message(upcb, addr, port, TFTP_ERR_FILE_NOT_FOUND);
/* close the connection */
tftp_cleanup_wr(upcb, args); /* close the connection */
}
/* update our block number to match the block number just received */
args->block++;
/* update total bytes */
(args->tot_bytes) += (pkt_buf->len - TFTP_DATA_PKT_HDR_LEN);
/* This is a valid pkt but it has no data. This would occur if the file being
written is an exact multiple of 512 bytes. In this case, the args->block
value must still be updated, but we can skip everything else. */
}
else if (tftp_extract_block(pkt_buf->payload) == (args->block + 1))
{
/* update our block number to match the block number just received */
args->block++;
}
/* SEndTransferthe appropriate ACK pkt (the block number sent in the ACK pkt echoes
* the block number of the DATA pkt we just received - see RFC1350)
* NOTE!: If the DATA pkt we received did not have the appropriate block
* number, then the args->block (our block number) is never updated and
* we simply sEndTransfera "duplicate ACK" which has the same block number as the
* last ACK pkt we sent. This lets the host know that we are still waiting
* on block number args->block+1. */
tftp_send_ack_packet(upcb, addr, port, args->block);
/* If the last write returned less than the maximum TFTP data pkt length,
* then we've received the whole file and so we can quit (this is how TFTP
* signals the EndTransferof a transfer!)
*/
if (pkt_buf->len < TFTP_DATA_PKT_LEN_MAX)
{
tftp_cleanup_wr(upcb, args);
pbuf_free(pkt_buf);
}
else
{
pbuf_free(pkt_buf);
return;
}
}