Point to Point interface over qmi_wwan device

[Reinhard Speyerer]

On Tue, Oct 04, 2016 at 08:12:15PM +0000, Tang Nguyen wrote:
> 
> --------------------------------------------
> On Tue, 10/4/16, Dan Williams <dcbw at redhat.com> wrote:
> 
>  Subject: Re: Point to Point interface over qmi_wwan device
>  To: "Tang Nguyen" <tang_nguyen at yahoo.com>, "Bjørn Mork" <bjorn at mork.no>
>  Cc: "libqmi (development)" <libqmi-devel at lists.freedesktop.org>
>  Date: Tuesday, October 4, 2016, 1:17 PM
>  
>  On Tue, 2016-10-04 at
>  16:28 +0000, Tang Nguyen wrote:
>  > Hi
>  all,
>  > I have tested /32 mask on wwan
>  without running dhclient. but seems
>  > not
>  working .  The  packet connection successfully connected
>  but it
>  > would be dropped after a
>  while.  Looks like Sierra firmware waits for
>  > dhclient discovery request from host, and
>  after a while it would
>  > disconnect the
>  data link.
>  > My module is MC7354 (ATT)
>  > What I did as below:
>  >
>  1. start network connection.  Verify connection status with
>  command:
>  > qmicli  -d /dev/cdc-wdm3
>  --wds-get-packet-service-status2. Send AT
>  > command to modem to show assigned IP
> > address3. Using ip command to 
>  
>  >Why use the AT command?  Why not:
>  
>  >qmicli -d /dev/cdc-wdm3
>  >--wds-get-current-settings --client-no-release-
>  >cid --client-cid=<cid from start
>  >network>
>  
>  >I seem to
>  >recall we've had devices before that didn't fully
>  >set up the
> > WAN interface until they got
>  >asked for the IP details, and I wouldn't
>  >necessarily trust the AT interpreter to do the
>  >same thing.  But the QMI
>  >GetCurrentSettings
>  >request might.
>  
> > Dan
> 
> Using libqmi doesn't help Dan.  I can see IP, assign it to cellular interface but still not able to ping outside
> 
> [/dev/cdc-wdm3] Connection status: 'connected'
> root at rx1500-2:~# qmicli -d /dev/cdc-wdm3 --wds-get-current-settings 
> [/dev/cdc-wdm3] Current settings retrieved:
>            IP Family: IPv4
>         IPv4 address: 10.106.63.25
>     IPv4 subnet mask: 255.255.255.252
> IPv4 gateway address: 10.106.63.26
>     IPv4 primary DNS: 207.219.69.11
>   IPv4 secondary DNS: 216.218.29.11
>                  MTU: 1430
>              Domains: none
> root at rx1500-2:~# ip add add 10.106.63.25/32 peer 10.106.63.26
> Not enough information: "dev" argument is required.
> root at rx1500-2:~# ip add add 10.106.63.25/32 peer 10.106.63.26 dev cel-6-1
> root at rx1500-2:~# ifconfig cel-6-1
> cel-6-1   Link encap:Ethernet  HWaddr 0e:9a:50:15:45:49  
>           inet addr:10.106.105.95  Bcast:0.0.0.0  Mask:255.255.255.255
>           inet6 addr: fe80::c9a:50ff:fe15:4549/64 Scope:Link
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:517 errors:29 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000 
>           RX bytes:0 (0.0 B)  TX bytes:99778 (97.4 KiB)

Hi Tang,

that matches the results from my tests with a MC7304. For MSM9x15
based devices like the MC7304 the use of DHCP seems to be a trigger to
pass IPv4 traffic over the network interface as long as it is set to
Ethernet mode. Only using a qmi_wwan version with raw IP support and
switching the mobile use raw IP with qmicli made this configuration
work for me without using a DHCP client.

Regards,
Reinhard