udhcpc: don't use BPF filter, users report problems (bugs 4598, 6746), commit e4785ca653d0e219926692c229673b2c1b8d6ac4

Cristian Ionescu-Idbohrn cristian.ionescu-idbohrn at axis.com
Tue Feb 4 19:48:38 UTC 2014


The backside of this, IIRC, is that udhcpc will eat up huge chunks of
CPU parsing "uninteresting" packets, on "heavy" loaded networks.

Bug #6746 names "FRITZ!Box 7570 router (mipsel)" and some unnamed
kernel version that "Apparently my kernel does not support this filter
feature".

Maybe a better alternative would be to either enable the "filter
kernel feature" (witch will not only benefit busybox, but the whole
system) or to make the BPF filtering a configurable busybox feature.
That way noone would need to patch the udhcpc source.

See also the kernel source:

	Documentation/networking/filter.txt


Cheers,

-- 
Cristian


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