kern/187550: Multiple interfaces on different FIBs but the same subnet don't all have a subnet route

[Alan Somers]

>Number:         187550
>Category:       kern
>Synopsis:       Multiple interfaces on different FIBs but the same subnet don't all have a subnet route
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Mar 13 17:50:01 UTC 2014
>Closed-Date:
>Last-Modified:
>Originator:     Alan Somers
>Release:        11.0-CURRENT  r262867
>Organization:
Spectra Logic
>Environment:
FreeBSD alans-fbsd-head 11.0-CURRENT FreeBSD 11.0-CURRENT #38 r262867M: Thu Mar  6 13:50:32 MST 2014     alans at ns1.eng.sldomain.com:/vmpool/obj/usr/home/alans/freebsd/head/sys/GENERIC  amd64
>Description:
When you UP an interface, the kernel automatically adds host and subnet routes.  However, if two interfaces are on the same subnet but have different FIBs, the second one to be created won't get a subnet route in its FIB.
>How-To-Repeat:
# ifconfig tap0 create
# ifconfig tap1 create
# setfib 2 ifconfig tap0 192.0.2.2/24 fib 2
# setfib 3 ifconfig tap1 192.0.2.3/24 fib 3
# setfib 2 netstat -rn -f inet
Routing tables (fib: 2)

Internet:
Destination        Gateway            Flags    Netif Expire
192.0.2.0/24       link#3             U        tap0
# setfib 3 netstat -rn -f inet
Routing tables (fib: 3)

Notice that FIB 3 does not contain a subnet route.
>Fix:
Working on a patch ...

>Release-Note:
>Audit-Trail:
>Unformatted: