[PATCH v2 0/2] 6lowpan fixes

[PATCH v2 0/2] 6lowpan fixes

[Alan Ott]

Fixes for 6lowpan.

I'm sorry about the other two emails that just went out with the same
subject.  One day I'm going to start getting these right on the first try.

Alan Ott (2):
  6lowpan: Make a copy of skb's delivered to 6lowpan
  6lowpan: handle NETDEV_UNREGISTER event

 net/ieee802154/6lowpan.c |   53 +++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 45 insertions(+), 8 deletions(-)

[PATCH v2 1/2] 6lowpan: Make a copy of skb's delivered to 6lowpan

[Alan Ott]

Since lowpan_process_data() modifies the skb (by calling skb_pull()), we
need our own copy so that it doesn't affect the data received by other
protcols (in this case, af_ieee802154).

Signed-off-by: Alan Ott <alan-yzvJWuRpmD1zbRFIqnYvSA@public.gmane.org>
---
 net/ieee802154/6lowpan.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 6a09522..ce33b02 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -1133,6 +1133,8 @@ static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
 	struct packet_type *pt, struct net_device *orig_dev)
 {
+	struct sk_buff *local_skb;
+
 	if (!netif_running(dev))
 		goto drop;
 
@@ -1144,7 +1146,12 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
 	case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
 	case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
 	case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
-		lowpan_process_data(skb);
+		local_skb = skb_copy(skb, GFP_ATOMIC);
+		if (!local_skb)
+			goto drop;
+		lowpan_process_data(local_skb);
+
+		kfree_skb(skb);
 		break;
 	default:
 		break;
-- 
1.7.0.4


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Re: [PATCH v2 1/2] 6lowpan: Make a copy of skb's delivered to 6lowpan

[Eric Dumazet]

On Wed, 2012-08-29 at 22:39 -0400, Alan Ott wrote:
> Since lowpan_process_data() modifies the skb (by calling skb_pull()), we
> need our own copy so that it doesn't affect the data received by other
> protcols (in this case, af_ieee802154).
> 
> Signed-off-by: Alan Ott <alan@signal11.us>
> ---
>  net/ieee802154/6lowpan.c |    9 ++++++++-
>  1 files changed, 8 insertions(+), 1 deletions(-)
> 
> diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
> index 6a09522..ce33b02 100644
> --- a/net/ieee802154/6lowpan.c
> +++ b/net/ieee802154/6lowpan.c
> @@ -1133,6 +1133,8 @@ static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
>  static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
>  	struct packet_type *pt, struct net_device *orig_dev)
>  {
> +	struct sk_buff *local_skb;
> +
>  	if (!netif_running(dev))
>  		goto drop;
>  
> @@ -1144,7 +1146,12 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
>  	case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
>  	case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
>  	case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
> -		lowpan_process_data(skb);
> +		local_skb = skb_copy(skb, GFP_ATOMIC);
> +		if (!local_skb)
> +			goto drop;
> +		lowpan_process_data(local_skb);
> +
> +		kfree_skb(skb);
>  		break;
>  	default:
>  		break;

Its not clear to me why skb_copy() is needed here.

>From patch description, I would say skb_clone() would be enough (and
faster) ?

Re: [PATCH v2 1/2] 6lowpan: Make a copy of skb's delivered to 6lowpan

[Alan Ott]

On 08/31/2012 03:01 AM, Eric Dumazet wrote:
> On Wed, 2012-08-29 at 22:39 -0400, Alan Ott wrote:
>> Since lowpan_process_data() modifies the skb (by calling skb_pull()), we
>> need our own copy so that it doesn't affect the data received by other
>> protcols (in this case, af_ieee802154).
>>
>> Signed-off-by: Alan Ott <alan-yzvJWuRpmD1zbRFIqnYvSA@public.gmane.org>
>> ---
>>  net/ieee802154/6lowpan.c |    9 ++++++++-
>>  1 files changed, 8 insertions(+), 1 deletions(-)
>>
>> diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
>> index 6a09522..ce33b02 100644
>> --- a/net/ieee802154/6lowpan.c
>> +++ b/net/ieee802154/6lowpan.c
>> @@ -1133,6 +1133,8 @@ static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
>>  static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
>>  	struct packet_type *pt, struct net_device *orig_dev)
>>  {
>> +	struct sk_buff *local_skb;
>> +
>>  	if (!netif_running(dev))
>>  		goto drop;
>>  
>> @@ -1144,7 +1146,12 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
>>  	case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
>>  	case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
>>  	case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
>> -		lowpan_process_data(skb);
>> +		local_skb = skb_copy(skb, GFP_ATOMIC);
>> +		if (!local_skb)
>> +			goto drop;
>> +		lowpan_process_data(local_skb);
>> +
>> +		kfree_skb(skb);
>>  		break;
>>  	default:
>>  		break;
> Its not clear to me why skb_copy() is needed here.
>
> >From patch description, I would say skb_clone() would be enough (and
> faster) ?

You're probably right. I'll check it out. Thanks.

Alan.

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[PATCH v2 2/2] 6lowpan: handle NETDEV_UNREGISTER event

[Alan Ott]

Before, it was impossible to remove a wpan device which had lowpan
attached to it.

Signed-off-by: Alan Ott <alan-yzvJWuRpmD1zbRFIqnYvSA@public.gmane.org>
---
 net/ieee802154/6lowpan.c |   44 +++++++++++++++++++++++++++++++++++++-------
 1 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index ce33b02..fb41e08 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -1063,12 +1063,6 @@ out:
 	return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
 }
 
-static void lowpan_dev_free(struct net_device *dev)
-{
-	dev_put(lowpan_dev_info(dev)->real_dev);
-	free_netdev(dev);
-}
-
 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
 {
 	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
@@ -1118,7 +1112,7 @@ static void lowpan_setup(struct net_device *dev)
 	dev->netdev_ops		= &lowpan_netdev_ops;
 	dev->header_ops		= &lowpan_header_ops;
 	dev->ml_priv		= &lowpan_mlme;
-	dev->destructor		= lowpan_dev_free;
+	dev->destructor		= free_netdev;
 }
 
 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
@@ -1244,6 +1238,34 @@ static inline void __init lowpan_netlink_fini(void)
 	rtnl_link_unregister(&lowpan_link_ops);
 }
 
+static int lowpan_device_event(struct notifier_block *unused,
+				unsigned long event,
+				void *ptr)
+{
+	struct net_device *dev = ptr;
+	LIST_HEAD(del_list);
+	struct lowpan_dev_record *entry, *tmp;
+
+	if (dev->type != ARPHRD_IEEE802154)
+		goto out;
+
+	if (event == NETDEV_UNREGISTER) {
+		list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
+			if (lowpan_dev_info(entry->ldev)->real_dev == dev)
+				lowpan_dellink(entry->ldev, &del_list);
+		}
+
+		unregister_netdevice_many(&del_list);
+	};
+
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block lowpan_dev_notifier = {
+	.notifier_call = lowpan_device_event,
+};
+
 static struct packet_type lowpan_packet_type = {
 	.type = __constant_htons(ETH_P_IEEE802154),
 	.func = lowpan_rcv,
@@ -1258,6 +1280,12 @@ static int __init lowpan_init_module(void)
 		goto out;
 
 	dev_add_pack(&lowpan_packet_type);
+
+	err = register_netdevice_notifier(&lowpan_dev_notifier);
+	if (err < 0) {
+		dev_remove_pack(&lowpan_packet_type);
+		lowpan_netlink_fini();
+	}
 out:
 	return err;
 }
@@ -1270,6 +1298,8 @@ static void __exit lowpan_cleanup_module(void)
 
 	dev_remove_pack(&lowpan_packet_type);
 
+	unregister_netdevice_notifier(&lowpan_dev_notifier);
+
 	/* Now 6lowpan packet_type is removed, so no new fragments are
 	 * expected on RX, therefore that's the time to clean incomplete
 	 * fragments.
-- 
1.7.0.4


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[PATCH v3 0/2] 6lowpan fixes

[Alan Ott]

v3 of this patch changes skb_copy() to skb_clone() in patch #1 at the
recommendation of Eric Dumazet

Alan Ott (2):
  6lowpan: Make a copy of skb's delivered to 6lowpan
  6lowpan: handle NETDEV_UNREGISTER event

 net/ieee802154/6lowpan.c |   53 +++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 45 insertions(+), 8 deletions(-)


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Re: [PATCH v3 0/2] 6lowpan fixes

[David Miller]

From: Alan Ott <alan@signal11.us>
Date: Sat,  1 Sep 2012 11:57:05 -0400

> v3 of this patch changes skb_copy() to skb_clone() in patch #1 at the
> recommendation of Eric Dumazet
> 
> Alan Ott (2):
>   6lowpan: Make a copy of skb's delivered to 6lowpan
>   6lowpan: handle NETDEV_UNREGISTER event

All applied to net-next, thanks.

[PATCH v3 1/2] 6lowpan: Make a copy of skb's delivered to 6lowpan

[Alan Ott]

Since lowpan_process_data() modifies the skb (by calling skb_pull()), we
need our own copy so that it doesn't affect the data received by other
protcols (in this case, af_ieee802154).

Signed-off-by: Alan Ott <alan-yzvJWuRpmD1zbRFIqnYvSA@public.gmane.org>
---
 net/ieee802154/6lowpan.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 6a09522..b28ec79 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -1133,6 +1133,8 @@ static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
 static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
 	struct packet_type *pt, struct net_device *orig_dev)
 {
+	struct sk_buff *local_skb;
+
 	if (!netif_running(dev))
 		goto drop;
 
@@ -1144,7 +1146,12 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
 	case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
 	case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
 	case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
-		lowpan_process_data(skb);
+		local_skb = skb_clone(skb, GFP_ATOMIC);
+		if (!local_skb)
+			goto drop;
+		lowpan_process_data(local_skb);
+
+		kfree_skb(skb);
 		break;
 	default:
 		break;
-- 
1.7.0.4


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[PATCH v3 2/2] 6lowpan: handle NETDEV_UNREGISTER event

[Alan Ott]

Before, it was impossible to remove a wpan device which had lowpan
attached to it.

Signed-off-by: Alan Ott <alan-yzvJWuRpmD1zbRFIqnYvSA@public.gmane.org>
---
 net/ieee802154/6lowpan.c |   44 +++++++++++++++++++++++++++++++++++++-------
 1 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index b28ec79..d529111 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -1063,12 +1063,6 @@ out:
 	return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
 }
 
-static void lowpan_dev_free(struct net_device *dev)
-{
-	dev_put(lowpan_dev_info(dev)->real_dev);
-	free_netdev(dev);
-}
-
 static struct wpan_phy *lowpan_get_phy(const struct net_device *dev)
 {
 	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
@@ -1118,7 +1112,7 @@ static void lowpan_setup(struct net_device *dev)
 	dev->netdev_ops		= &lowpan_netdev_ops;
 	dev->header_ops		= &lowpan_header_ops;
 	dev->ml_priv		= &lowpan_mlme;
-	dev->destructor		= lowpan_dev_free;
+	dev->destructor		= free_netdev;
 }
 
 static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[])
@@ -1244,6 +1238,34 @@ static inline void __init lowpan_netlink_fini(void)
 	rtnl_link_unregister(&lowpan_link_ops);
 }
 
+static int lowpan_device_event(struct notifier_block *unused,
+				unsigned long event,
+				void *ptr)
+{
+	struct net_device *dev = ptr;
+	LIST_HEAD(del_list);
+	struct lowpan_dev_record *entry, *tmp;
+
+	if (dev->type != ARPHRD_IEEE802154)
+		goto out;
+
+	if (event == NETDEV_UNREGISTER) {
+		list_for_each_entry_safe(entry, tmp, &lowpan_devices, list) {
+			if (lowpan_dev_info(entry->ldev)->real_dev == dev)
+				lowpan_dellink(entry->ldev, &del_list);
+		}
+
+		unregister_netdevice_many(&del_list);
+	};
+
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block lowpan_dev_notifier = {
+	.notifier_call = lowpan_device_event,
+};
+
 static struct packet_type lowpan_packet_type = {
 	.type = __constant_htons(ETH_P_IEEE802154),
 	.func = lowpan_rcv,
@@ -1258,6 +1280,12 @@ static int __init lowpan_init_module(void)
 		goto out;
 
 	dev_add_pack(&lowpan_packet_type);
+
+	err = register_netdevice_notifier(&lowpan_dev_notifier);
+	if (err < 0) {
+		dev_remove_pack(&lowpan_packet_type);
+		lowpan_netlink_fini();
+	}
 out:
 	return err;
 }
@@ -1270,6 +1298,8 @@ static void __exit lowpan_cleanup_module(void)
 
 	dev_remove_pack(&lowpan_packet_type);
 
+	unregister_netdevice_notifier(&lowpan_dev_notifier);
+
 	/* Now 6lowpan packet_type is removed, so no new fragments are
 	 * expected on RX, therefore that's the time to clean incomplete
 	 * fragments.
-- 
1.7.0.4


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