CIFS implementation

[viku]

Hii,

Can anyone tell me about ServerGUID[16] field in SMB negotiation response message and how to calculate it in linux 2.4.

[tetsujin]

Hii,

Can anyone tell me about ServerGUID[16] field in SMB negotiation response message and how to calculate it in linux 2.4.

Just a guess here...

But a GUID - a "Guaranteed Unique Identifier" - in the Windows sense is a 128 bit (that is, 16 byte) value. There's a few different ways to calculate one which are supposed to calculate values which are, statistically speaking, almost guaranteed to give you a GUID value that no one else who has ever calculated a GUID would get. I don't know all the algorithms in too much detail - some of them, I believe, would combine information about your own computer (such as the MAC address of the network card - also guaranteed unique) with some random bits or bits from the current time...

Anyway, it seems likely that what's important here is just that the GUID each host uses is unique, at least among the other hosts in the network. You could probably just generate a random number, or make one up - it just has to be unique on the network and specific to that host. Maybe check out "libuuid" or "uuidcdef" if you want a more rigorous implementation.

[viku]

thanks for ur reply but the confusion is about the use of this field....because we are not registering this field anywhere..then how the windows client will come to know about server's identity or if u can tell me the exact use of GUID field in CIFS the i'll really appreciate ur reply....

Just a guess here...

But a GUID - a "Guaranteed Unique Identifier" - in the Windows sense is a 128 bit (that is, 16 byte) value. There's a few different ways to calculate one which are supposed to calculate values which are, statistically speaking, almost guaranteed to give you a GUID value that no one else who has ever calculated a GUID would get. I don't know all the algorithms in too much detail - some of them, I believe, would combine information about your own computer (such as the MAC address of the network card - also guaranteed unique) with some random bits or bits from the current time...

Anyway, it seems likely that what's important here is just that the GUID each host uses is unique, at least among the other hosts in the network. You could probably just generate a random number, or make one up - it just has to be unique on the network and specific to that host. Maybe check out "libuuid" or "uuidcdef" if you want a more rigorous implementation.

[tetsujin]

thanks for ur reply but the confusion is about the use of this field....because we are not registering this field anywhere..then how the windows client will come to know about server's identity or if u can tell me the exact use of GUID field in CIFS the i'll really appreciate ur reply....

Nope, afraid I can't help you there. Ah, well.