[PATCH] Bluetooth: 6lowpan: Fix multi-link setup

[PATCH] Bluetooth: 6lowpan: Fix multi-link setup

[Luiz Augusto von Dentz]

From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

If there are more than one node connected and there isn't any route
information attempt to check if destination address matches any of the
link-local peer addresses.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 net/bluetooth/6lowpan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index 4e2576fc0c59..55370c330386 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -190,7 +190,7 @@ static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 		nexthop = &lowpan_cb(skb)->gw;
 
 		if (ipv6_addr_any(nexthop))
-			return NULL;
+			nexthop = daddr;
 	} else {
 		nexthop = rt6_nexthop(rt, daddr);
 
-- 
2.13.5

Re: [PATCH] Bluetooth: 6lowpan: Fix multi-link setup

[Jukka Rissanen]

Hi Luiz,

On Wed, 2017-09-20 at 12:52 +0300, Luiz Augusto von Dentz wrote:
> From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> 
> If there are more than one node connected and there isn't any route
> information attempt to check if destination address matches any of
> the
> link-local peer addresses.
> 
> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
> ---
>  net/bluetooth/6lowpan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
> index 4e2576fc0c59..55370c330386 100644
> --- a/net/bluetooth/6lowpan.c
> +++ b/net/bluetooth/6lowpan.c
> @@ -190,7 +190,7 @@ static inline struct lowpan_peer
> *peer_lookup_dst(struct lowpan_btle_dev *dev,
>  		nexthop = &lowpan_cb(skb)->gw;
>  
>  		if (ipv6_addr_any(nexthop))
> -			return NULL;
> +			nexthop = daddr;
>  	} else {
>  		nexthop = rt6_nexthop(rt, daddr);
>  


Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>


Cheers,
Jukka

Re: [PATCH] Bluetooth: 6lowpan: Fix multi-link setup

[Michael Scott]

Hi Luiz (and linux-bluetooth),

On Wed, 2017-09-20 at 12:52 +0300, Luiz Augusto von Dentz wrote:
>/From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>/
>//
>/If there are more than one node connected and there isn't any route/
>/information attempt to check if destination address matches any of/
>/the/
>/link-local peer addresses./
>//
>/Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>/
>/---/
>/net/bluetooth/6lowpan.c | 2 +-/
>/1 file changed, 1 insertion(+), 1 deletion(-)/
>//
>/diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c/
>/index 4e2576fc0c59..55370c330386 100644/
>/--- a/net/bluetooth/6lowpan.c/
>/+++ b/net/bluetooth/6lowpan.c/
>/@@ -190,7 +190,7 @@ static inline struct lowpan_peer/
>/*peer_lookup_dst(struct lowpan_btle_dev *dev,/
>/nexthop = &lowpan_cb(skb)->gw;/
>//
>/if (ipv6_addr_any(nexthop))/
>/- return NULL;/
>/+ nexthop = daddr;/
>/} else {/
>/nexthop = rt6_nexthop(rt, daddr);/
>//

Was there any plan to bring this into the longterm 4.14 tree?  I saw 
that Jukka ACKed the patch.

Using 4.14, connecting more than 1 node via 6lowpan is completely 
broken.  This fairly simple patch restores connectivity for multiple 
6lowpan devices.

Question: Are there any hidden downsides to using this patch?

- Mike

Re: [PATCH] Bluetooth: 6lowpan: Fix multi-link setup

[Luiz Augusto von Dentz]

Hi Michael,

On Thu, Dec 7, 2017 at 4:26 PM, Michael Scott
<michael@opensourcefoundries.com> wrote:
> Hi Luiz (and linux-bluetooth),
>
> On Wed, 2017-09-20 at 12:52 +0300, Luiz Augusto von Dentz wrote:
>>
>> /From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>/
>> //
>> /If there are more than one node connected and there isn't any route/
>> /information attempt to check if destination address matches any of/
>> /the/
>> /link-local peer addresses./
>> //
>> /Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>/
>> /---/
>> /net/bluetooth/6lowpan.c | 2 +-/
>> /1 file changed, 1 insertion(+), 1 deletion(-)/
>> //
>> /diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c/
>> /index 4e2576fc0c59..55370c330386 100644/
>> /--- a/net/bluetooth/6lowpan.c/
>> /+++ b/net/bluetooth/6lowpan.c/
>> /@@ -190,7 +190,7 @@ static inline struct lowpan_peer/
>> /*peer_lookup_dst(struct lowpan_btle_dev *dev,/
>> /nexthop = &lowpan_cb(skb)->gw;/
>> //
>> /if (ipv6_addr_any(nexthop))/
>> /- return NULL;/
>> /+ nexthop = daddr;/
>> /} else {/
>> /nexthop = rt6_nexthop(rt, daddr);/
>> //
>
>
> Was there any plan to bring this into the longterm 4.14 tree?  I saw that
> Jukka ACKed the patch.
>
> Using 4.14, connecting more than 1 node via 6lowpan is completely broken.
> This fairly simple patch restores connectivity for multiple 6lowpan devices.
>
> Question: Are there any hidden downsides to using this patch?

No really, we are just going to deprecated the debugfs interface thus
this got deprioritized, but perhaps we should apply one last fix
before moving on.

-- 
Luiz Augusto von Dentz