A route generated from an RTF_CLONING route had the RTF_WASCLONED flag
set but did not have a reference to the parent route, as documented in
the rtentry(9) manpage. This prevented such routes from being deleted
when their parent route is deleted.
Now, for example, if you delete an IP address from a network interface,
all ARP entries that were cloned from this interface route are flushed.
This also has an impact on netstat(1) output. Previously, dynamically
created ARP cache entries (RTF_STATIC flag is unset) were displayed as
part of the routing table display (-r). Now, they are only printed if
the -a option is given.
netinet/in.c, netinet/in_rmx.c:
When address is removed from an interface, also delete all routes that
point to this interface and address. Previously, for example, if you
changed the address on an interface, outgoing IP datagrams might still
use the old address. The only solution was to delete and re-add some
routes. (The problem is easily observed with the route(8) command.)
Note, that if the socket was already bound to the local address before
this address is removed, new datagrams generated from this socket will
still be sent from the old address.
PR: kern/20785, kern/21914
Reviewed by: wollman (the idea)
089cdfad78