On 02.05.2016 19:25, Marcel Holtmann wrote:
> 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 <da...@davemloft.net>
>> Cc: Alexey Kuznetsov <kuz...@ms2.inr.ac.ru>
>> Cc: James Morris <jmor...@namei.org>
>> Cc: Hideaki YOSHIFUJI <yoshf...@linux-ipv6.org>
>> Cc: Patrick McHardy <ka...@trash.net>
>>
>> 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?

My proposal would be that the IPv6 patches go via net-next to reduce
merge conflicts with maybe upcoming changes. If they are split up, they
seem very much self contained and easy to review. The rest seems to be
also very much self contained and can go in via bluetooth-next, then.
What do you think?

Bye,
Hannes

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