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| author | Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu> | 2024-07-12 13:47:54 +0400 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2024-08-01 08:10:00 -0600 |
| commit | 1dd034ec001152b37ba3d9a60bf892b445886e8b (patch) | |
| tree | c355a2bf1221e1e67257045dae8df44bc90388d2 | |
| parent | fb2f2a38b6c52d8f80d7b0a0589fd0fb93c3973c (diff) | |
| download | u-boot-1dd034ec001152b37ba3d9a60bf892b445886e8b.tar.gz u-boot-1dd034ec001152b37ba3d9a60bf892b445886e8b.tar.bz2 u-boot-1dd034ec001152b37ba3d9a60bf892b445886e8b.zip | |
net/tftp: make tftpput working with servers that do not use OACK
Option Acknowledgment (OACK) is an extension of TFTP protocol (see rfc2347).
Not all tftp servers implements it. For example it does not supported by
tftpd server from debian-11 (https://packages.debian.org/bullseye/tftpd).
Starting the "tftpput $loadaddr $size out_file" command with such server
will results in the following packets flow:
192.168.27.3 192.168.27.1 TFTP Write Request, ...
192.168.27.1 192.168.27.3 TFTP Acknowledgement, Block: 0
192.168.27.3 192.168.27.1 TFTP Write Request, ...
192.168.27.1 192.168.27.3 TFTP Acknowledgement, Block: 0
192.168.27.3 192.168.27.1 TFTP Write Request, ...
192.168.27.1 192.168.27.3 TFTP Acknowledgement, Block: 0
192.168.27.1 192.168.27.3 TFTP Acknowledgement, Block: 0
192.168.27.1 192.168.27.3 TFTP Acknowledgement, Block: 0
...
so, no data transfer happening.
Here is a packets flow for tftp-server with OACK support
(tftpd-hpa: https://packages.debian.org/stable/tftpd-hpa)
192.168.27.3 192.168.27.1 TFTP Write Request, ...
192.168.27.1 192.168.27.3 TFTP Option Acknowledgement, ...
192.168.27.3 192.168.27.1 TFTP Data Packet, Block: 1
192.168.27.1 192.168.27.3 TFTP Acknowledgement, Block: 1
192.168.27.3 192.168.27.1 TFTP Data Packet, Block: 2
192.168.27.1 192.168.27.3 TFTP Acknowledgement, Block: 2
and this time data transfer starts normally.
As we can see there is no OACK packet in the first case. Investigating
an issue we'll find out:
1) tftp_start() sets
tftp_state = STATE_SEND_WRQ;
2) on OACK tftp_handler() sets
tftp_state = STATE_DATA;
and send a first DATA packet.
3) on ACK tftp_handler() will call a tftp_send() function.
tftp_send() will
* tftpd with OACK support:
Current state is STATE_DATA, so transmittion of data packet will
happen.
* tftpd without OACK support
Current state is STATE_SEND_WRQ, so retransmission of WRQ packet
will happen. Thus tftpd-server will retransmit an ACK.
This will repeats until timeout happens.
According to RFC1350 this is wrong. We should start data transfer
instead of WRQ retransmission.
This patch fix an issue, so tftpput works fine with both types of servers.
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
| -rw-r--r-- | net/tftp.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/net/tftp.c b/net/tftp.c index 65c39d7fb7..2e073183d5 100644 --- a/net/tftp.c +++ b/net/tftp.c @@ -493,8 +493,15 @@ static void tftp_handler(uchar *pkt, unsigned dest, struct in_addr sip, tftp_prev_block = tftp_cur_block; tftp_cur_block = (unsigned short)(block + 1); update_block_number(); - if (ack_ok) + if (ack_ok) { + if (block == 0 && + tftp_state == STATE_SEND_WRQ){ + /* connection's first ACK */ + tftp_state = STATE_DATA; + tftp_remote_port = src; + } tftp_send(); /* Send next data block */ + } } } #endif |