netdev - Re: Is this 32-bit NCM?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <alpine.LNX.2.03.1411271351280.10442@gmail.com>
Date:	Thu, 27 Nov 2014 13:55:12 +0100 (CET)
From:	Enrico Mioso <mrkiko.rs@...il.com>
To:	Alex Strizhevsky <alexxst@...il.com>
cc:	Bjørn Mork <bjorn@...k.no>,
	ShaojunMidge.Tan@...iocodes.com, Mingying.Zhu@...iocodes.com,
	Enrico Mioso <mrkiko.rs@...il.com>, youtux@...il.com,
	linux-usb@...r.kernel.org, netdev@...r.kernel.org,
	Eli.Britstein@...iocodes.com
Subject: Re: Is this 32-bit NCM?

On Thu, 27 Nov 2014, Alex Strizhevsky wrote:

==Date: Thu, 27 Nov 2014 13:36:37
==From: Alex Strizhevsky <alexxst@...il.com>
==To: Bjørn Mork <bjorn@...k.no>, ShaojunMidge.Tan@...iocodes.com,
==    Mingying.Zhu@...iocodes.com
==Cc: Enrico Mioso <mrkiko.rs@...il.com>, youtux@...il.com,
==    linux-usb@...r.kernel.org, netdev@...r.kernel.org,
==    Eli.Britstein@...iocodes.com
==Subject: Re: Is this 32-bit NCM?
==
==Adding my colleagues - Eli, Kevin & Midge.
==
==Any ideas are welcome ;)
==
==
==On Thu, Nov 27, 2014 at 12:03 PM, Bjørn Mork <bjorn@...k.no> wrote:
==      Enrico Mioso <mrkiko.rs@...il.com> writes:
==
==      > Ok - we can arrive to some ocnclusions regarding the E3272.
==      > First of all - the modem seems buggy enough to not be able to
==      handle requests
==      > for different formats. You need to unplug and re-plug it, but
==      this is onlyan
==      > impression and is reasonable.
==      >
==      > Then - the modem will accept to ndisdup the connection with
==      > at^ndisdup=1,1,"internet"
==      > but - if we use huawei_cdc_ncm + cdc_ncm we have no flow
==      handling messages and
==      > the modem stops here.
==      > If we use the cdc_ncm 32-bit driver (modified) we get lotfs of
==      > ^dsflorpt
==      > that's how it should be.
==      > So I think we can say that something is changing.
==      > Then there's the alignment problem you mentioned in your
==      previous reply. And
==      > this is hard to solve.
==      > could you try to help me understand where the problem is?
==      > I feel like we are very close to the solution but something
==      isn't working.
==      > Or might be just try to change the 16 bit driver?
==
==If you use a recent version of the driver as a basis, then you get the
==CDC NCM NTB parameters in sysfs (if not, then you need to enable
==debugging and look in the log for these values).  For example:
==
==bjorn@...i:~$ grep . /sys/class/net/wwan0/cdc_ncm/*
==/sys/class/net/wwan0/cdc_ncm/bmNtbFormatsSupported:0x0001
==/sys/class/net/wwan0/cdc_ncm/dwNtbInMaxSize:15360
==/sys/class/net/wwan0/cdc_ncm/dwNtbOutMaxSize:15360
==/sys/class/net/wwan0/cdc_ncm/min_tx_pkt:13824
==/sys/class/net/wwan0/cdc_ncm/rx_max:15360
==/sys/class/net/wwan0/cdc_ncm/tx_max:15360
==/sys/class/net/wwan0/cdc_ncm/tx_timer_usecs:400
==/sys/class/net/wwan0/cdc_ncm/wNdpInAlignment:4
==/sys/class/net/wwan0/cdc_ncm/wNdpInDivisor:1
==/sys/class/net/wwan0/cdc_ncm/wNdpInPayloadRemainder:0
==/sys/class/net/wwan0/cdc_ncm/wNdpOutAlignment:4
==/sys/class/net/wwan0/cdc_ncm/wNdpOutDivisor:32
==/sys/class/net/wwan0/cdc_ncm/wNdpOutPayloadRemainder:0
==/sys/class/net/wwan0/cdc_ncm/wNtbOutMaxDatagrams:32
==
In kernel 3.16 you have these funcitonalities, so please use a kernel as recent 
as 3.16 at least, so that you bill be able to gather an modify some of these 
parameters easily.
==
==The possible problem I am thinking of is proper handling of the
==wNdp*PayloadRemainder values. See section 3.3.4 "NCM Ethernet Frame
==Alignment" in the spec.  Which is confusing as hell, but if I
==understand
==it correctly then we are supposed to align the start of the IP packets
==(the "payload", _not_ the ethernet frame) to a whole wNdp*Divisor
==number
==as long as the wNdp*PayloadRemainder is 0.
So probably the cdc_ncm_frame_fill and *_fixup functions need to be a little 
bit modified. Looking at the captures I am not able to understand this fully. 
And in general, I would not be able to change alingment. Alessio?
==
==
==Bjørn
==
==
==
==