calling ioctl(SIOC[AS]IFADDR).
This allows the following:
ifconfig xx0 inet 1.2.3.1 netmask 0xffffff00
ifconfig xx0 inet 1.2.3.17 netmask 0xfffffff0 alias
ifconfig xx0 inet 1.2.3.25 netmask 0xfffffff8 alias
ifconfig xx0 inet 1.2.3.26 netmask 0xffffffff alias
but would (given the above) reject this:
ifconfig xx0 inet 1.2.3.27 netmask 0xfffffff8 alias
due to the conflicting netmasks. I would assert that it's wrong
to mask the EEXIST returned from rtinit() as in the above scenario, the
deletion of the 1.2.3.25 address will leave the 1.2.3.27 address
as unroutable as it was in the first place.
Offered for review on: -arch, -net
Discussed with: stephen macmanus <stephenm@bayarea.net>
MFC after: 3 weeks
6ce6e2be71