LinuxLists.cc - [PATCH bluetooth-next 00/10] 6lowpan: introduce basic 6lowpan-nd

2016-04-18 10:58:18

Subject: [PATCH bluetooth-next 00/10] 6lowpan: introduce basic 6lowpan-nd

Hi,

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 <[email protected]>
Cc: Alexey Kuznetsov <[email protected]>
Cc: James Morris <[email protected]>
Cc: Hideaki YOSHIFUJI <[email protected]>
Cc: Patrick McHardy <[email protected]>

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 | 101 ++++++-
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, 1094 insertions(+), 158 deletions(-)
create mode 100644 net/6lowpan/ndisc.c

--
2.8.0

2016-04-18 15:04:05

by kernel test robot

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Subject: Re: [PATCH bluetooth-next 09/10] 6lowpan: introduce 6lowpan-nd

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2016-04-18 14:23:01

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2016-04-18 12:59:11

This patch will introduce a 6lowpan neighbour private data. Like the
interface private data we handle private data for generic 6lowpan and
for link-layer specific 6lowpan.

The current first use case if to save the short address for a 802.15.4
6lowpan neighbour.

Cc: David S. Miller <[email protected]>
Signed-off-by: Alexander Aring <[email protected]>
---
include/linux/netdevice.h | 3 +--
include/net/6lowpan.h | 24 ++++++++++++++++++++++++
net/bluetooth/6lowpan.c | 2 ++
net/ieee802154/6lowpan/core.c | 12 ++++++++++++
4 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 166402a..0052c42 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1487,8 +1487,7 @@ enum netdev_priv_flags {
* @perm_addr: Permanent hw address
* @addr_assign_type: Hw address assignment type
* @addr_len: Hardware address length
- * @neigh_priv_len; Used in neigh_alloc(),
- * initialized only in atm/clip.c
+ * @neigh_priv_len; Used in neigh_alloc()
* @dev_id: Used to differentiate devices that share
* the same link layer address
* @dev_port: Used to differentiate devices that share
diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
index da84cf9..61c6517 100644
--- a/include/net/6lowpan.h
+++ b/include/net/6lowpan.h
@@ -98,6 +98,9 @@ static inline bool lowpan_is_iphc(u8 dispatch)
#define LOWPAN_PRIV_SIZE(llpriv_size) \
(sizeof(struct lowpan_dev) + llpriv_size)

+#define LOWPAN_NEIGH_PRIV_SIZE(llneigh_priv_size) \
+ (sizeof(struct lowpan_neigh) + llneigh_priv_size)
+
enum lowpan_lltypes {
LOWPAN_LLTYPE_BTLE,
LOWPAN_LLTYPE_IEEE802154,
@@ -141,6 +144,27 @@ struct lowpan_dev {
u8 priv[0] __aligned(sizeof(void *));
};

+struct lowpan_neigh {
+ /* 6LoWPAN neigh private data */
+ /* must be last */
+ u8 priv[0] __aligned(sizeof(void *));
+};
+
+struct lowpan_802154_neigh {
+ __le16 short_addr;
+};
+
+static inline struct lowpan_neigh *lowpan_neigh(void *neigh_priv)
+{
+ return neigh_priv;
+}
+
+static inline
+struct lowpan_802154_neigh *lowpan_802154_neigh(void *neigh_priv)
+{
+ return (struct lowpan_802154_neigh *)lowpan_neigh(neigh_priv)->priv;
+}
+
static inline
struct lowpan_dev *lowpan_dev(const struct net_device *dev)
{
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 38e82dd..b7c4efa 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -833,6 +833,8 @@ static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
spin_unlock(&devices_lock);

+ netdev->neigh_priv_len = LOWPAN_NEIGH_PRIV_SIZE(0);
+
err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
if (err < 0) {
BT_INFO("register_netdev failed %d", err);
diff --git a/net/ieee802154/6lowpan/core.c b/net/ieee802154/6lowpan/core.c
index dd085db..3162632 100644
--- a/net/ieee802154/6lowpan/core.c
+++ b/net/ieee802154/6lowpan/core.c
@@ -92,11 +92,21 @@ static int lowpan_stop(struct net_device *dev)
return 0;
}

+static int lowpan_neigh_construct(struct neighbour *n)
+{
+ struct lowpan_802154_neigh *neigh = lowpan_802154_neigh(neighbour_priv(n));
+
+ /* default no short_addr is available for a neighbour */
+ neigh->short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
+ return 0;
+}
+
static const struct net_device_ops lowpan_netdev_ops = {
.ndo_init = lowpan_dev_init,
.ndo_start_xmit = lowpan_xmit,
.ndo_open = lowpan_open,
.ndo_stop = lowpan_stop,
+ .ndo_neigh_construct = lowpan_neigh_construct,
};

static void lowpan_setup(struct net_device *ldev)
@@ -161,6 +171,8 @@ static int lowpan_newlink(struct net *src_net, struct net_device *ldev,
wdev->needed_headroom;
ldev->needed_tailroom = wdev->needed_tailroom;

+ ldev->neigh_priv_len = LOWPAN_NEIGH_PRIV_SIZE(sizeof(struct lowpan_802154_neigh));
+
ret = lowpan_register_netdevice(ldev, LOWPAN_LLTYPE_IEEE802154);
if (ret < 0) {
dev_put(wdev);
--
2.8.0