kern/165305: Feature parity between IP_TOS and IPV6_TCLASS

[Mark Andrews]

>Number:         165305
>Category:       kern
>Synopsis:       Feature parity between IP_TOS and IPV6_TCLASS
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Mon Feb 20 01:20:10 UTC 2012
>Closed-Date:
>Last-Modified:
>Originator:     Mark Andrews
>Release:        FreeBSD 8.2-STABLE i386
>Organization:
ISC
>Environment:
System: FreeBSD sex.dv.isc.org 8.2-STABLE FreeBSD 8.2-STABLE #15: Thu Dec 29 08:21:01 EST 2011 marka at sex.dv.isc.org:/usr/obj/usr/src/sys/DEBUG i386


>Description:

	IPV6_TCLASS can be set on both a socket basis and on a per
	packet basis.  Additionally IPV6_TCLASS can be received via
	a control message by setting IPV6_RECVTCLASS on the socket.

	IP_TOS can only be set socket basis with no per packet
	control which makes it setting different the TOS in UDP
	replies difficult (i.e.  require raw sockets to be used).

	Additionally the only way to obtain the IP_TOS field is to
	use raw sockets or use a packet filter.
	
>How-To-Repeat:
>Fix:

	Extend control_msg to support setting IP_TOS on a per packet
	basis.

	Add a new setsockopt (IP_RECVTOS to be consistent with
	linux's extension to the socket API) and return the value
	via a control_msg.
>Release-Note:
>Audit-Trail:
>Unformatted: