Add and use new RTF_CONNECTED flag to mark connected routes

[guyyur_gmail.com]

Summary

The flag will be used to allow IPv6 neighbor routes
when they are added by userland (bug 194485).

Reusing the same value as RTF_CLONING for
compatibility with NetBSD.

RTF_CONNECTED added based on locations RTF_CLONING was
removed from in r186119 and on NetBSD changes converting
RTF_CLONING to RTF_CONNECTED.

[araujo]

Any news about this patch?

[hsw_bitmark.com]

I user D15404 + D15405 + D15406 on current kernel to get an updated net/dhcpcd to work

Now with rc.conf containing:

ifconfig_re0="DHCP"
ifconfig_re0_ipv6="inet6"
dhclient_program="/usr/local/sbin/dhcpcd"

and dhcpcd-7.1.1 installed - changed Makefile version and ran:

make makesum && make install

I used pfsense DHCPv6 and the router mode set to "managed" I was able to get static IPv6 address assigned

I am using kernel: FreeBSD 13.0-CURRENT #2 r346220M

[melifaro]

I read the problem description from the PR194485 and looked in the other (D15405, D15406) patches.

I fully agree we should fix the problem (and D15405 approach looks sane). I don't fully understand why do we need a separate flag for these routes. How are they different from the any other non-gatewayed routes? If the some address is directly reachable via the interface it should be possible to communicate with it directly.

[hsw_bitmark.com]

It also works on 12.0-RELEASE-p3 using same process as my previous comment

[guyyur_gmail.com]

Abandon in favor of D23695