[Libssh] Experiencing Issue with sftp_write Call

[Fujiwara, Daisuke]

Hello,



First of all, I would like to thank everyone who has contributed to this
great library.

I was hoping that I can get some help from people out there with this
particular problem I have been experiencing.



We are using the libssh version 0.11, and we have a call to the
sftp_write function given the length of data to write as 262173 bytes.



It seems that the libssh library writes 131035 bytes followed by 128037
bytes of data after appropriate remote window resizing.

However, the library then receives an EOF message from the server
instead of another window resizing message.

This is unexpected because we still have 3101 more bytes to write.



When this happens, the channel_write function gets stuck in the
while(channel->remote_window==0) in the channel_write function.

Because there are no more packets to be read from the server, our recv
call blocks.



I have attached the output from the libssh library below.

Please take a look at them and let me know if this is a known issue in
version 0.11 and whether the version 0.2 of the library has addressed
this particular problem.





Thank you,

Daisuke Fujiwara





- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

growing window (channel 42:0) to 32000 bytes

sftp server version 3

Writing on the wire a packet having 37 bytes before,37 bytes after comp
+ 6 padd

ing bytes = 44 bytes packet

seq num = 11, len = 48

channel_write wrote 28 bytes

Decrypting 8 bytes data

size decrypted : 24

Read a 36 bytes packet

Decrypting 32 bytes data

9 bytes padding

Final size 26

type 94

Channel_handle(94)

adding 17 bytes data in 0

placing 17 bytes into channel buffer (stderr=0)

Writing on the wire a packet having 9 bytes before,9 bytes after comp +
10 padding bytes = 20 bytes packet

seq num = 12, len = 24

growing window (channel 42:0) to 32000 bytes

packet with id 1 type 102

queued msg type 1 id 102

dequeued msg id 1 type 102

Remote window is 131035 bytes. going to write 262173 bytes

Waiting for a growing window message...

Writing on the wire a packet having 131044 bytes before,131044 bytes
after comp

+ 7 padding bytes = 131052 bytes packet

seq num = 13, len = 131056

channel_write wrote 131035 bytes

Remote window is 0 bytes. going to write 131138 bytes

Waiting for a growing window message...

Decrypting 8 bytes data

size decrypted : 14

Read a 20 bytes packet

Decrypting 16 bytes data

10 bytes padding

Final size 9

type 93

Channel_handle(93)

Adding 128037 bytes to channel (42:0) (from 0 bytes)

Writing on the wire a packet having 128046 bytes before,128046 bytes
after comp

+ 5 padding bytes = 128052 bytes packet

seq num = 14, len = 128056

channel_write wrote 128037 bytes

Remote window is 0 bytes. going to write 3101 bytes

Waiting for a growing window message...

Decrypting 8 bytes data

size decrypted : c

Read a 12 bytes packet

Decrypting 8 bytes data

6 bytes padding

Final size 5

type 96

Channel_handle(96)

Received eof on channel (42:0)

Decrypting 8 bytes data

size decrypted : 24

Read a 36 bytes packet

Decrypting 32 bytes data

10 bytes padding

Final size 25

type 98

Channel_handle(98)

Decrypting 8 bytes data

size decrypted : c

Read a 12 bytes packet

Decrypting 8 bytes data

6 bytes padding

Final size 5

type 97

Channel_handle(97)

Received close on channel (42:0)

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