[jcifs] Large Read/Write Patch

M. D. moder at abv.bg
Wed Dec 17 06:30:34 MST 2014


I'm uploading a new patch. It now contains checks if signatures are desired. If that's the case then the old buffer size is used.

Best regards,

 >-------- Оригинално писмо --------
 >От:   M. D.  
 >Относно: Re: [jcifs] Large Read/Write Patch
 >До: Robin Jansohn 
 >Изпратено на: Сряда, 2014, Декември 17 10:58:08 EET
 > Hello,
 >I also confirm that read/write operations with the patch applied are significantly faster.
 >However, I think there is a problem with the patch:
 >According to the official SMB documentation: 
 >... sections, 
 >"Capabilities (4 bytes): A 32-bit field providing a set of server capability indicators. This bit field is
 >used to indicate to the client which features are supported by the server. Any value not listed in the
 >following table is unused. The server MUST set the unused bits to zero. The client MUST ignore
 >these bits.". 
 >The CAP_LARGE_WRITEX flag that is part of the Capabilities (4 bytes) field is responsible for:
 >"The server supports large write operations. This
 >capability affects the maximum size, in bytes, of the
 >server buffer for receiving an SMB_COM_WRITE_ANDX
 >client request. When this capability is set by the server
 >(and set by the client in the
 >SMB_COM_SESSION_SETUP_ANDX request), then the
 >maximum server buffer size of bytes it writes can
 >exceed the MaxBufferSize field. Therefore, a client
 >can send a single SMB_COM_WRITE_ANDX request up
 >to this size.
 >When signing is active on a connection, then clients
 >MUST limit write lengths to the MaxBufferSize value
 >negotiated by the server, irrespective of the value of
 >the CAP_LARGE_WRITEX flag."
 >... so it is true that we can safely ignore the MaxBufferSize and send larger chunks of data UNLESS signing is active on a connection. Therefore, I think checks for signing should be added to the patch. 
 >Hope that helps!
 >Best regards,
 > >-------- Оригинално писмо --------
 > >От:  Robin Jansohn 
 > >Относно: Re: [jcifs] Large Read/Write Patch
 > >До: jcifs at lists.samba.org
 > >Изпратено на: Понеделник, 2014, Декември 15 09:08:49 EET
 > >
 > >
 > >No, I'm using a Maven repository and although I explicitly excluded the
 > >package it somehow did not work as expected. The test itself is run in a
 > >simple Main class, no webapp or similar large application.
 > >
 > >
 > >
 > >--
 > >View this message in context: http://samba.2283325.n4.nabble.com/Large-Read-Write-Patch-tp3674893p4677877.html
 > >Sent from the Samba - jcifs mailing list archive at Nabble.com.
 > >
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