847388 - DHCP broken on Nexus S when WiFi Tethering enabled

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: Wifi, defect)

Description

[:gerard-majax]

Basically, DHCP is up and running, but badly configured system, thus:

I/dnsmasq ( 4122): started, version 2.51 cachesize 150
I/dnsmasq ( 4122): compile time options: no-IPv6 GNU-getopt no-DBus no-I18N DHCP no-scripts no-TFTP
W/dnsmasq ( 4122): warning: no upstream servers configured
I/dnsmasq ( 4122): DHCP, IP range 192.168.1.10 -- 192.168.1.30, lease time 1h
I/dnsmasq ( 4122): read /etc/hosts - 1 addresses
I/dnsmasq ( 4122): using nameserver 212.27.40.241#53
I/dnsmasq ( 4122): using nameserver 212.27.40.240#53
W/dnsmasq ( 4122): DHCP packet received on wl0.1 which has no address
W/dnsmasq ( 4122): DHCP packet received on wl0.1 which has no address
W/dnsmasq ( 4122): DHCP packet received on wl0.1 which has no address
W/dnsmasq ( 4122): DHCP packet received on wl0.1 which has no address
W/dnsmasq ( 4122): DHCP packet received on wl0.1 which has no address
W/dnsmasq ( 4122): DHCP packet received on wl0.1 which has no address

Comment 1

[:gerard-majax]

http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2011q3/005165.html

«  On 2011-07-22 23:05, Michael Fork wrote:
> Is it possible to use dnsmasq to serve DHCP on an interface with no IP Address?

The answer is right there: http://tools.ietf.org/html/rfc2131
To save you some time: no, it is not possible. »

Comment 2

[:gerard-majax]

Attachment: Using wl0.1 instead of wlan0 for DHCP and NAT fixes the issue

Attached a patch that fixes the issue by using the wl0.1 network interface instead of wlan0 for both DHCP and NAT operations.

Comment 3

[:gerard-majax]

Attachment: Picture demonstrating workness.

This is for real!

Comment 4

[Vincent Chang[:vchang][changyihsin]]

Comment on attachment 720698 [details] [diff] [review]
Using wl0.1 instead of wlan0 for DHCP and NAT fixes the issue

Review of attachment 720698 [details] [diff] [review]:
-----------------------------------------------------------------

This patch looks wrong to me because some devices such as unagi and otoro don't have the wl0.1 interface.
If the problem is related to name of wifi interface, we should better to detect it automatically.

Comment 5

[:gerard-majax]

Attachment: Using wl0.1 as DHCP and NAT interface on Nexus S

For some reason, the driver and/or netd are bringing up the network on
wl0.1 when we expect this to be on wlan0 interface. Let's then use wl0.1
for both handling the DHCP request and for the NAT. This will allow to
use WiFi Tethering properly. One consequence of this workaround is that
you need to either manually unload and reload the WiFi kernel driver or
reboot the device after using WiFi Tethering, otherwise the stack ends
in an unexpected state.

Comment 6

[Chuck Lee [:chucklee, Triggered by NI, Review, and Feedback requests]]

Comment on attachment 720698 [details] [diff] [review]
Using wl0.1 instead of wlan0 for DHCP and NAT fixes the issue

This patch is out-dated.

Comment 7

[:gerard-majax]

FYI, the problem of having to reload the driver after disabling tethering can be mitigated by setting the ro.moz.wifi.unloaddriver property to 1. For the wl0.1 naming issue, I could not find anything explicitely explaining what happens: we set the device to be an access point via the iw kernel interface, and everything seems to be done kernel-side.

Comment 8

[:gerard-majax]

Unassigning as I'm stopping dogfooding Nexus S.

Comment 9

[:gerard-majax]

Attachment: Using wl0.1 as DHCP and NAT interface on Nexus S

For some reason, the driver and/or netd are bringing up the network on
wl0.1 when we expect this to be on wlan0 interface. Let's then use wl0.1
for both handling the DHCP request and for the NAT. This will allow to
use WiFi Tethering properly. One consequence of this workaround is that
you need to either manually unload and reload the WiFi kernel driver or
reboot the device after using WiFi Tethering, otherwise the stack ends
in an unexpected state.

Comment 10

[BMO Automation]

Firefox OS is not being worked on