From mboxrd@z Thu Jan 1 00:00:00 1970 From: Krishna Kumar Subject: Re: [PATCH] Prefix List against 2.5.70 (re-done) Date: Thu, 10 Jul 2003 15:16:25 -0700 Sender: netdev-bounce@oss.sgi.com Message-ID: <3F0DE5B9.20702@us.ibm.com> References: <20030627.144752.78715628.davem@redhat.com> <20030628.130602.63704890.yoshfuji@linux-ipv6.org> <3F008771.5030206@us.ibm.com> <20030702.091825.72842784.yoshfuji@linux-ipv6.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: davem@redhat.com, netdev@oss.sgi.com, linux-net@vger.kernel.org, kuznet@ms2.inr.ac.ru Return-path: To: yoshfuji@linux-ipv6.org In-Reply-To: <20030702.091825.72842784.yoshfuji@linux-ipv6.org> Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org > You do not explain why we (or kernel) NEED(s) this. > It is not so important how SMALL it is > though it may cause problems how LARGE it is. I had explained the reasons for having prefix list i/f in my previous mail. To recap : - User don't need to know what the definition of a prefix is, all he has to do is ask the kernel and get the list. Otherwise different user apps will have to know the definition of a prefix and parse the entry themselves. The parsing is non-trivial (eg the address should not LL or MC, there should be no nexthop and it should be added via an RA, etc). - The kernel code to get the prefix list is small, the top level inet6_dump_fib uses either the dump_node or the dump_prefix, the latter being the new user interface. Having a user interface makes it easier to get the prefix list without significant bloat to the kernel. > This is design issue; how we should provide L3 per-interface > information to userspace; eg. in_device and/or inet6_dev things > including per-interface statistics. > > Since I think it is not appropriate to provide per-interface > statistics via RTM_xxxROUTE, so I don't agree to provide > the RA infomation (i.e. Manage/Otherconf Flags) via > RTM_xxxROUTE. > > Options: > - use RTM_xxxLINK for L3 operation > - introduce RTM_xxxIFACE for L3 per-interface operations Yes, there are a couple of different ways to do this. One is as you have suggested, but there is a problem with it. The existing RTM_GETLINK interface returns very generic elements of the dev (mtu, hardware address, dev statistics), while the change you suggested is specific to ipv6. I am not sure if this is a good design to implement. Either we could use the current (submitted) way or use a different RTM_GETADDR interface in inet6_fill_ifaddr (and introduce RTM_IFACEFLAGS). This will be specific to IPv6. Are you agreeable to this ? > Well, on moving forward; you can split your patch up to 3 things: > 1. fix routing flags > 2. provide Managed/Otherconf flags API > (3. provide the prefix list API (if it IS required)) > > I'm not against the first item. > We need to discuss on the design related to the 2nd item. > I don't think that we really need 3rd item. - I am ok with 1 :-) - I have suggested changes for 2, please let me know what you think, whether we can go with the old way or make the change suggested above. - I believe we need #3 for the reasons given above. Thanks, - KK