IPv6 uplink prefix length limited to two characters

[opcode]

Hi,

I was trying to set up IPv6 today and I noticed the prefixlength field is limited to two characters.
Some ISPs use /126 so this basically prevents us from configuring IPv6 in GUI.

For now I'll try setting up everything manually through CLI. But it would be nice to fix this GUI restriction.
It's trivial: maxlength="2" should be changed to maxlength="3" for prefixlengths.

 

[RMerlin]

No so trivial, as it required checking the codepath to ensure that there was no internal buffers that would be overrun by accepting 3 characters instead of just 2 (fortunately, Asus seems to have ensured that sufficient large buffers are used for IPv6 prefixes). Other parts of the webui also needed to be updated to accept values greater than 64.

https://github.com/RMerl/asuswrt-merlin/commit/abfc8bafc5cd8368da3c25db1d63d632b65aa8d7