pfSense

Fix double rc.newwanipv6 execution on if_pppoe

When using if_pppoe and DHCPv6 over the PPP link, both the devd handler script
and dhcp6c execute /etc/rc.newwanipv6 as a result of an address assignment,
which is not fatal but does cause some extra delay as the filter is reloaded and...

pppoe-handler: Mute spurious invalid address warnings

Move the address checking out of the main body of the script into switch cases
that actually use the address

(cherry picked from commit 51ce224e061a26728bb42d11d238a11bbd989850)

if_pppoe: Resolve endless loop on dhcp6c

When using if_pppoe, the use of ppp-ipv6 to up the pppoe interface on ADDR_ADD
causes a loop of calling interface_dhcp6_configure(), which
restarts dhcp6c, which acquires a lease and assigns an address, which emits an...

Fix config check for if_pppoe

'system/use_mpd5_for_pppoe' is not a valid config path.

Keep IPv4 addresses on IPv6 ppp-linkdown events. Fix #16103

Co-authored-by David King <8408971+strix-technica@users.noreply.github.com>

pppoe: Add new pppoe-handler script

Add a new script, pppoe-handler, that will be called by devd when proper
events happen on pppoe interfaces.

(cherry picked from commit 79f87326c412ae6291c82b6aa13e5a0fcd3a94af)

Properly quote these variables and use the built-in echo

Remove SED as it is now unused

Simplify clearing the arp table by using functionality built into arp(1)

Properly quote these variables and avoid using test -o