kern/43317: Several bugs in gre

[kab00m%geo.phys.spbu.ru@localhost]

>Number:         43317
>Category:       kern
>Synopsis:       Several bugs in gre
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun May 16 23:05:00 +0000 2010
>Originator:     Dima Veselov
>Release:        NetBSD 5.1_RC1
>Organization:
>Environment:
System: NetBSD neo 5.1_RC1 NetBSD 5.1_RC1 (Aliguera) #2: Thu May 13 00:11:42 
MSD 2010 kab00m@neo:/usr/obj/sys/arch/amd64/compile/Aliguera amd64
Architecture: x86_64
Machine: amd64
>Description:
        First, applying adress to gre(4) before bringing it up cause immediate 
panic and reboot. Can't catch message, something about mutex locking against 
itself.
        Second, route doesn't allow -interface on gre, saying bad value. I 
don't know if it is a bug, but FreeBSD allow this.
        Third, making a tunnel as documented cause computer freeze upon first 
usage. I don't know if it has to be allowed, gre(4) manpage and implementation 
should be consistent.
>How-To-Repeat:
        1. 
        ifconfig gre0 create
        ifconfig gre0 inet 10.11.11.11/23 10.11.11.12
        Here goes panic

        3.
        ifconfig gre0 create
        ifconfig gre0 10.10.10.10 10.10.10.11 netmask 0xffffffff up
        ifconfig gre0 tunnel 10.10.10.10 10.10.10.11
        route add 192.168.10/24 10.10.10.11
        telnet 192.168.10.1
        Here computer freezes

>Fix:
        1. 
        Just bring gre up before assigning address
        ifconfig gre0 create
        ifconfig gre0 up
        ifconfig gre0 inet 10.11.11.11/23 10.11.11.12
        3.
        Don't use same addresses inside tunnel, use virtual ones
        ifconfig gre0 create 
        ifconfig gre0 172.20.20.1 172.20.20.2 netmask 0xffffffff up
        ifconfig gre0 tunnel 10.10.10.10 10.10.10.11
        route add 192.168.10/24 10.10.10.11

>Unformatted:
        Downloaded from ftp.