Return-Path: Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Subject: Re: [PATCHv2 bluetooth-next 00/10] 6lowpan: introduce basic 6lowpan-nd From: Marcel Holtmann In-Reply-To: <1461140382-4784-1-git-send-email-aar@pengutronix.de> Date: Mon, 2 May 2016 10:25:00 -0700 Cc: linux-wpan@vger.kernel.org, kernel@pengutronix.de, Jukka Rissanen , hannes@stressinduktion.org, Stefan Schmidt , mcr@sandelman.ca, Werner Almesberger , Linux Bluetooth , Network Development , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy Message-Id: References: <1461140382-4784-1-git-send-email-aar@pengutronix.de> To: Alexander Aring , "David S. Miller" Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Dave, > this patch series introduces a layer for IPv6 neighbour discovery. At first > it introduce the "ndisc_ops" to run a different handling for recv/send of > NA/NS messages. The use case for such ndisc operation is RFC 6775 [0]. > Which describes a different neighbour discovery handling for 6LoWPAN networks. > > I didn't implement RFC 6775 in this patch series, but introduce callback > structure for replace different functions in ndisc implementation might be > the right direction. > > Another use case would be RFC 7400 [1] which describes a new option field to > getting capabilities of 6LoWPAN next header compression methods. > > What I implemented is a necessary functionality to handle short address for > 802.15.4 6LoWPAN networks. The L2-Layer "802.15.4" can have two different > link-layer addresses which can be used mixed at the same time inside 802.15.4 > networks. To deal with such behaviour in ndisc, it is defined at RFC 4944 [2]. > The bad news is, that I saw different handling of such handling. What Linux > will do is to add two source/target address information option fields, each > with different length, if short address is valid (can also not be given). > Example: > > - WPAN interface address settings > - extended addr (must always be there) > - short addr (0xfffe or 0xffff -> invalid) > > Will add an extended addr to source/target address information option field. > If short addr is in some valid range, then both address will be added to > the option fields. Indicated are these different address types by the length > field (extended -> length=2, short -> length=1), according to [1]. > > The tested 6LoWPAN implementation (RIOT-OS) allows only one source/target > option field which is short XOR extended, otherwise it will be dropped. > There is some lack of information there [2] and I don't know how do deal with > it right, maybe we need to update the implementation there if it's really > wrong. > > To save such information for each neighbour we use the already implemented > neighbour private data which some casting strategy for 6LoWPAN and 6LoWPAN > link-layer specific data e.g. 802.15.4 short address handling. > > Additional I implemented to add 6CO to the is_useropt callback in case of > 6LoWPAN interface. The 6CO option will currently parsed in userspace which > are placed in RA-Messages. > > The ndisc_ops are not finished yet, of course we need handling for RS messages > to place the 802.15.4 short address there as well and then also processing > of RA messages for the 802.15.4 SLLAO option field. > > - Alex > > [0] https://tools.ietf.org/html/rfc6775 > [1] https://tools.ietf.org/html/rfc7400#section-3.3 > [2] https://tools.ietf.org/html/rfc4944#section-8 > > Cc: David S. Miller > Cc: Alexey Kuznetsov > Cc: James Morris > Cc: Hideaki YOSHIFUJI > Cc: Patrick McHardy > > changes since v2: > - replace #ifdef CONFIG_IPV6 to #if IS_ENABLED(...) > - replace #ifdef CONFIG_IEEE802154... to #if IS_ENABLED(...) > - add more #if IS_ENABLED(CONFIG_IPV6) in ndisc.h > > Alexander Aring (10): > 6lowpan: add private neighbour data > 6lowpan: add 802.15.4 short addr slaac > 6lowpan: remove ipv6 module request > ndisc: add addr_len parameter to ndisc_opt_addr_space > ndisc: add addr_len parameter to ndisc_opt_addr_data > ndisc: add addr_len parameter to ndisc_fill_addr_option > ipv6: introduce neighbour discovery ops > ipv6: export ndisc functions > 6lowpan: introduce 6lowpan-nd > 6lowpan: add support for 802.15.4 short addr handling > > include/linux/netdevice.h | 6 +- > include/net/6lowpan.h | 24 ++ > include/net/addrconf.h | 3 + > include/net/ndisc.h | 124 ++++++++- > net/6lowpan/6lowpan_i.h | 2 + > net/6lowpan/Makefile | 2 +- > net/6lowpan/core.c | 50 +++- > net/6lowpan/iphc.c | 167 +++++++++-- > net/6lowpan/ndisc.c | 633 ++++++++++++++++++++++++++++++++++++++++++ > net/bluetooth/6lowpan.c | 2 + > net/ieee802154/6lowpan/core.c | 12 + > net/ieee802154/6lowpan/tx.c | 107 ++++--- > net/ipv6/addrconf.c | 7 +- > net/ipv6/ndisc.c | 132 +++++---- > net/ipv6/route.c | 4 +- > 15 files changed, 1117 insertions(+), 158 deletions(-) > create mode 100644 net/6lowpan/ndisc.c is there a chance that we get input into this patch set? I wonder also if it would be acceptable to take this through bluetooth-next or should it better go straight into net-next? Regards Marcel