kern/52795: loading if_gif module generates duplicate ip_ecn_xxx symbols

[paul%whooppee.com@localhost]

>Number:         52795
>Category:       kern
>Synopsis:       ip_ecn_xxx duplicate symbols between if_gif and stf(4)
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Dec 08 22:50:00 +0000 2017
>Originator:     Paul Goyette
>Release:        NetBSD 8.99.7
>Organization:
+------------------+--------------------------+----------------------------+
| Paul Goyette     | PGP Key fingerprint:     | E-mail addresses:          |
| (Retired)        | FA29 0E3B 35AF E8AE 6651 | paul at whooppee dot com   |
| Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd dot org |
+------------------+--------------------------+----------------------------+
>Environment:
	
	
System: NetBSD speedy.whooppee.com 8.99.7 NetBSD 8.99.7 (SPEEDY 2017-11-29 22:03:05 UTC) #0: Wed Nov 29 23:14:50 UTC 2017 paul%speedy.whooppee.com@localhost:/build/netbsd-local/obj/amd64/sys/arch/amd64/compile/SPEEDY amd64
Architecture: x86_64
Machine: amd64
>Description:
The if_gif module includes a copy of ip_ecn.c routines, which are also
used by the stf(4) driver (not yet modular).  If a kernel is built with
stf(4) included and gif(4) excluded, and then you load the if_gif module,
you get duplicate symbol error messages for ip_ecn_{e,in}gress and the
module fails to load.
	
>How-To-Repeat:
See above
	
>Fix:
Separate the ip_ecn routines out into a separate module, and make the
if_gif module require ip_ecn.  Then, loading of if_gif will auto-load
ip_ecn if not already built-in.  (If stf(4) is already included in the
kernel, ip_ecn would be built-in and no need to load another copy.)
	

>Unformatted: