What is maximum SMB2 IOCTL(FSCTL_GET_SHADOW_COPY) response size.

[Richard Sharpe]

On Tue, Jan 20, 2015 at 7:08 PM, Hemanth Thummala
<hemanth.thummala at gmail.com> wrote:
> I have modified one of smbtorture tests(smb2.ioctl.shadow_copy) to test
> this case.
> Test is passed. Linux client is able to received the response which is >
> 64KB.
>
> No.     Time            Source                Destination
> Protocol Length Info
> 175 15:31:33.621624 xx.xx.xx.xx       yy.yy.yy.yy           SMB2     160
>  Ioctl Response FSCTL_GET_SHADOW_COPY_DATA File: \FOOBAR
>
> Transmission Control Protocol, Src Port: 445 (445), Dst Port: 43314
> (43314), Seq: 87971, Ack: 1194, Len: 94
> [65 Reassembled TCP Segments (87134 bytes): #73(1360), #76(1360),
> #78(1360), #80(1360), #82(1360), #84(1360), #86(1360), #88(1360),
> #90(1360), #92(1360), #94(1360), #96(1360), #98(1360), #100(1360),
> #102(1360), #104(1360), #106(1360), #108(]
> NetBIOS Session Service
> SMB2 (Server Message Block Protocol version 2)
>     SMB2 Header
>     Ioctl Response (0x0b)
>         StructureSize: 0x0031
>         unknown: 0000
>         Function: FSCTL_GET_SHADOW_COPY_DATA (0x00144064)
>         GUID handle File: \FOOBAR
>         In Data: NO DATA
>             Offset: 0x00000070
>             Length: 0
>         Out Data
>             Offset: 0x00000070
>             Length: 87018 =====> greater than 64KB.
>             Num Volumes: 1740
>             Num Labels: 1740
>             Count: 87006
>             Label: @GMT-2015.01.20-17.00.01
>             Label: @GMT-2015.01.20-16.00.00
>             Label: @GMT-2015.01.20-15.00.00
>             ....
>
> Based on this test, this issue looks very specific to windows client(smb
> client) on all available OS versions.
> Unfortunately, we would still have to provide patch from server end(to
> limit the response to 64K) till MS fix this problem.

Good luck in getting MS to fix the problem.

-- 
Regards,
Richard Sharpe
(何以解憂？唯有杜康。--曹操)