About trusting the MBIM IP configuration...

[Bjørn Mork]

More interesting stuff from the Sierra Wireless EM7345 module.  Mine is
still running the 'FIH7160_V1.1_MODEM_01.1349.12' firmware, which is
what it came with originally.  I believe there are newer versions out
there, but I haven't gotten around to connecting it to a Windows system
yet.  And I have no idea how to even find a new firmware without the
Windows utilities.

Anyway, as usual I believe we need to support whatever firmware bugs
have been distributed in the wild, if we can.  And the IP configuration
data from this module is... ehm... odd.  Today I noticed another part of
that, this time affecting IPv4.

This is what I got:

ModemManager[27720]: <debug> [1417076748.897637] [mm-bearer-mbim.c:212] ip_configuration_query_ready(): IPv4 configuration available: 'address, gateway, dns'
ModemManager[27720]: <debug> [1417076748.897736] [mm-bearer-mbim.c:218] ip_configuration_query_ready():   IP addresses (1)
ModemManager[27720]: <debug> [1417076748.897873] [mm-bearer-mbim.c:222] ip_configuration_query_ready():     IP [0]: '10.143.52.0/24'
ModemManager[27720]: <debug> [1417076748.897988] [mm-bearer-mbim.c:231] ip_configuration_query_ready():   Gateway: '10.143.52.1'
ModemManager[27720]: <debug> [1417076748.898083] [mm-bearer-mbim.c:239] ip_configuration_query_ready():   DNS addresses (2)
ModemManager[27720]: <debug> [1417076748.898194] [mm-bearer-mbim.c:244] ip_configuration_query_ready():     DNS [0]: '193.213.112.4'
ModemManager[27720]: <debug> [1417076748.898307] [mm-bearer-mbim.c:244] ip_configuration_query_ready():     DNS [1]: '130.67.15.198'
ModemManager[27720]: <debug> [1417076748.898411] [mm-bearer-mbim.c:258] ip_configuration_query_ready(): IPv6 configuration available: 'address, gateway, dns'
ModemManager[27720]: <debug> [1417076748.898500] [mm-bearer-mbim.c:264] ip_configuration_query_ready():   IP addresses (1)
ModemManager[27720]: <debug> [1417076748.898612] [mm-bearer-mbim.c:268] ip_configuration_query_ready():     IP [0]: 'fe80::b:fb7d:4f01/120'
ModemManager[27720]: <debug> [1417076748.898726] [mm-bearer-mbim.c:277] ip_configuration_query_ready():   Gateway: 'a8f:3400:fe80::1'
ModemManager[27720]: <debug> [1417076748.898821] [mm-bearer-mbim.c:285] ip_configuration_query_ready():   DNS addresses (2)
ModemManager[27720]: <debug> [1417076748.898932] [mm-bearer-mbim.c:290] ip_configuration_query_ready():     DNS [0]: '2001:4600:4:fff::52'
ModemManager[27720]: <debug> [1417076748.899070] [mm-bearer-mbim.c:290] ip_configuration_query_ready():     DNS [1]: '2001:4600:4:1fff::52'
ModemManager[27720]: <debug> [1417076748.899303] [mm-port.c:95] mm_port_set_connected(): (wwan0): port now connected


So, starting with some problems I've observed before:

1) most of the time it will not report the global IPv6 prefix, but just
   a link local address (with a /120 mask for some reason beyond me...)

2) the IPv6 gateway is completely fucked up (obviously off by a few
   bytes) on IPV4V6 dual stack connections


And todays news:

3) the IPv4 netmask is fixed as /24 even in cases where this is
   impossible, like when the assigned address ends in '.0'


I do wonder what they smoke in the Intel/Sierra firmware labs....  It
cannot be healthy.  The good news is that they get all the DNS server
addresses right.



Bjørn