kern/174897: Interface routes are broken

[Peter Wemm]

>Number:         174897
>Category:       kern
>Synopsis:       Interface routes are broken
>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:   Wed Jan 02 13:40:01 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Peter Wemm
>Release:        10-current
>Organization:
FreeBSD
>Environment:
FreeBSD mailspool.freebsd.org 10.0-CURRENT FreeBSD 10.0-CURRENT #2 r244957: Wed Jan  2 11:18:56 UTC 2013
>Description:
Interface creation now fails to correctly install more-specific routes, or gets terribly confused.

This happens in two cases that are critical for freebsd.org cluster infrastructure machines.

1) Discard interface as a supernet is broken..

2) jail loopback substitution aliases are broken.
>How-To-Repeat:
The most urgent problem:

peter at mailspool:# % netstat -rn | grep 127
127.0.0.1          link#3             UH          0        0    lo0
root at mailspool:/home/peter # ifconfig -a | fgrep 127.0
        inet 127.0.0.1 netmask 0xff000000
root at mailspool:/home/peter # ifconfig lo1 create
root at mailspool:/home/peter # ifconfig -a | fgrep 127.0
        inet 127.0.0.1 netmask 0xff000000
root at mailspool:/home/peter # netstat -rn | grep 127
127.0.0.1          link#3             UH          0        0    lo0
root at mailspool:/home/peter # ifconfig lo1 inet 127.0.3.1/32 alias
ifconfig: ioctl (SIOCAIFADDR): File exists
root at mailspool:/home/peter # netstat -rn | grep 127
127.0.0.1          link#3             UH          0        0    lo0
127.0.3.1          link#4             UHS         0        0    lo0
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Note how it created something on the wrong interface.

root at mailspool:/home/peter # ifconfig lo1 | grep 127
root at mailspool:/home/peter # ifconfig lo0 | grep 127
	inet 127.0.0.1 netmask 0xff000000
root at mailspool:/home/peter # ifconfig lo1 inet 127.0.3.1/32 -alias
ifconfig: ioctl (SIOCDIFADDR): Can't assign requested address
root at mailspool:/home/peter # netstat -rn | grep 127
127.0.0.1          link#3             UH          0        0    lo0
127.0.3.1          link#4             UHS         0        0    lo0

. and deleting the interface address doesn't work either.

root at mailspool:/home/peter # ifconfig lo1 destroy
root at mailspool:/home/peter # netstat -rn | grep 127
127.0.0.1          link#3             UH          0        0    lo0
127.0.3.1          link#4             UHS         0        0    lo0
root at mailspool:/home/peter # route delete 127.0.3.1
delete host 127.0.3.1
root at mailspool:/home/peter # netstat -rn | grep 127
127.0.0.1          link#3             UH          0        0    lo0

Trying it with a network instead of a host doesn't work either.

root at mailspool:/home/peter # ifconfig lo1 create
root at mailspool:/home/peter # ifconfig lo1 127.0.1.1/24
ifconfig: ioctl (SIOCAIFADDR): File exists
root at mailspool:/home/peter # netstat -rn | grep 127
127.0.0.1          link#3             UH          0        0    lo0
127.0.1.1          link#4             UHS         0        0    lo0

>Fix:


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