confuzed bit flags

confuzed bit flags

[Randy.Dunlap]

I'm confused or the source code is or both.

net/ipv6/ndisc.c sets

	rt->rt6i_flags    = RTF_LOCAL;

This is OK AFAIK since RTF_LOCAL is #defined in
./linux/ipv6_route.h:36:#define RTF_LOCAL       0x80000000

But then RTF_LOCAL is never used anywhere else.  OK or not?

Further checking finds that net/ipv6/xfrm6_policy.c does this:

		x->u.rt6.rt6i_flags    = rt0->rt6i_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);

but these RTCF_ bits are defined in include/linux/in_route.h,
which says:

/* IPv4 routing cache flags */

So it's nice or good that RTF_LOCAL and RTCF_LOCAL are both
#defined as 0x80000000.  Right?

Oh, I see now that there's even a comment that might be applicable
to this <stuff>:
		/* Sheit... I remember I did this right. Apparently,
		 * it was magically lost, so this code needs audit */

I guess that my (idealistic) position is that those RTCF_ bit flags
shouldn't be used here (in net/ipv6) at all.  Am I off track on this?

--
~Randy

Re: confuzed bit flags

[David S. Miller]

   From: "Randy.Dunlap" <rddunlap@osdl.org>
   Date: Thu, 8 May 2003 15:30:32 -0700
   
   I'm confused or the source code is or both.
   
   net/ipv6/ndisc.c sets
   
   	rt->rt6i_flags    = RTF_LOCAL;
   
Any time you see some absolutely strange handling inside of ipv6
routing, it usually indicates a place where ipv4 routing does things
one way and the ipv6 side cannot implement things in that way for one
reason or another.  Yet, some ipv4'lets remain in the ipv6 code,
almost as a marker to be mindful of this difference.

This RTF_LOCAL thing is just such a case.

In many ways the ipv6 routing code is lacking in features that
ipv4 routing has.  I'm in fact right now killing on of them,
rtnetlink route metrics are ignored by ipv6.