Nest: Improve keeping track of IPv6 link-local addresses
Most protocols in IPv6 mode use link-local source addresses and expect that there is one on each active interface. The old code depended on assumption that if there is some IPv6 address on iface, there is also an IPv6 link-local address on that iface (added by kernel when the iface went up). Unfortunately, that is not generally true, as a configured global address sometimes ceases to be tentative (finishes DOD) before a link-local address on the same iface. In such case a protocol iface (namely RAdv and Babel) is activated, but fails to found link-local address and stays in failed state. The patch fixes that by tracking 'primary' IPv6 link-local address, sending iface restart notifications when it changes and making protocols ignore iface-up notifications when no such address is selected for an iface.
Showing with 46 additions and 37 deletions