FS#1415 - [Enhancement] Consider shorter interface-name prefixes

[openwrt-bot]

jeffsf:

Given that IFNAMSIZ is typically 16, there are 15 characters available for an interface name.

OpenWRT prepends a prefix that can be at least 6 characters gre4t- as an example.

If one then creates pseudo/virtual-interfaces using VLAN notation, there are only 4 characters available for configuration

gre4t-ABCD.1234

As long as this limitation is known, there is no loss of functionality, only utility in the naming. I would have ideally been able to name my tunnels with a more readable indication of where the other endpoint was, for example portal1 rather than gt99.

At some time in the future, shortening these generated prefixes would be welcome. I acknowledge that this likely impacts only a small fraction of advanced users and a change may impact scripts that rely on the generated name.