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[PATCHv2,bluetooth-next,01/10] 6lowpan: add private neighbour data

Message ID 1461140382-4784-2-git-send-email-aar@pengutronix.de (mailing list archive)
State Superseded
Headers show

Commit Message

Alexander Aring April 20, 2016, 8:19 a.m. UTC
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 <davem@davemloft.net>
Signed-off-by: Alexander Aring <aar@pengutronix.de>
---
 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(-)

Comments

Hannes Frederic Sowa May 2, 2016, 6:59 p.m. UTC | #1
Hello,

On 20.04.2016 10:19, Alexander Aring wrote:
> 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 <davem@davemloft.net>
> Signed-off-by: Alexander Aring <aar@pengutronix.de>
> ---
>  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 *));

Are you sure this declaration is correct? You take its size above, which
should result in zero. Looks a little bit strange. :)

> +};
> +
> +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;
> +}

Can't you remove lowpan_neigh completely and just use 802154_neigh at
this point?

Bye,
Hannes

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Stefan Schmidt May 3, 2016, 6:16 p.m. UTC | #2
Hello.

On 20/04/16 10:19, Alexander Aring wrote:
> 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<davem@davemloft.net>
> Signed-off-by: Alexander Aring<aar@pengutronix.de>
> ---
>   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);

Reviewed-by: Stefan Schmidt<stefan@osg.samsung.com>

regards
Stefan Schmidt
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Alexander Aring May 4, 2016, 10:43 a.m. UTC | #3
Hi,

On 05/02/2016 08:59 PM, Hannes Frederic Sowa wrote:
> Hello,
> 
> On 20.04.2016 10:19, Alexander Aring wrote:
>> 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 <davem@davemloft.net>
>> Signed-off-by: Alexander Aring <aar@pengutronix.de>
>> ---
>>  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 *));
> 
> Are you sure this declaration is correct? You take its size above, which
> should result in zero. Looks a little bit strange. :)
> 

I think yes it's correct, but I will remove it.

The basic idea here is to introduce a 6LoWPAN neighbour private data and
Link-Layer specific neighbour private data.

Example:

6LoWPAN neighbour data:

The GHC capability, 6LoWPAN contains some compression methods, also for
several Next Header (UDP, IPv6 extension headers, ...). So far I
understand each neighbour can tell which compression method it supports
by a special option field, see [0].

Such data doesn't depends on Link-Layer and is the same for all 6LoWPAN
over FOO standards.

6LoWPAN Link-Layer specific neighbour data:

Like the short address handling in case of 6LoWPAN over 802.15.4.

>> +};
>> +
>> +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;
>> +}
> 
> Can't you remove lowpan_neigh completely and just use 802154_neigh at
> this point?

Yes, I remove it. I think to introduce such layer for 6LoWPAN neighbour
data, we can still introduce it later when we have an use-case. Also with
a better foo_ops structure so we have something like this:

6lowpan interface:
 - .ndo_neigh_construct
   - "doing 6lowpan stuff"
     - .ndo_ll_neigh_construct
       - "doing ll 6lowpan stuff"

and ".ndo_ll_neigh_construct" differs in case of 6lowpan ll
implementation (802.15.4 or BTLE currently).

- Alex

[0] https://tools.ietf.org/html/rfc7400#section-3.3
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diff mbox

Patch

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);