[PATCH 0/2] Handle Uncompressed IPv6 on 6LoWPAN

[PATCH 0/2] Handle Uncompressed IPv6 on 6LoWPAN

[Alan Ott]

This has been tested by exchanging data with with the Contiki operating
system using a Redwire Econotag.  Contiki had to be set to send uncompressed
data, and had to have a #define modified to enable reception and processing
of header-compressed packets when not set to send compressed data.

Alan Ott (2):
  6lowpan: Refactor packet delivery into a function
  6lowpan: Handle uncompressed IPv6 packets over 6LoWPAN

 net/ieee802154/6lowpan.c | 79 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 56 insertions(+), 23 deletions(-)

-- 
1.7.11.2

[PATCH 1/2] 6lowpan: Refactor packet delivery into a function

[Alan Ott]

Refactor the handing of the skb's to the individual lowpan devices into a
function.

Signed-off-by: Alan Ott <alan@signal11.us>
---
 net/ieee802154/6lowpan.c | 38 ++++++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 14 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index f651da6..1714cfa 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -594,10 +594,32 @@ static int lowpan_header_create(struct sk_buff *skb,
 	}
 }
 
+static int lowpan_give_skb_to_devices(struct sk_buff *skb)
+{
+	struct lowpan_dev_record *entry;
+	struct sk_buff *skb_cp;
+	int stat = NET_RX_SUCCESS;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(entry, &lowpan_devices, list)
+		if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
+			skb_cp = skb_copy(skb, GFP_ATOMIC);
+			if (!skb_cp) {
+				stat = -ENOMEM;
+				break;
+			}
+
+			skb_cp->dev = entry->ldev;
+			stat = netif_rx(skb_cp);
+		}
+	rcu_read_unlock();
+
+	return stat;
+}
+
 static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
 {
 	struct sk_buff *new;
-	struct lowpan_dev_record *entry;
 	int stat = NET_RX_SUCCESS;
 
 	new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
@@ -614,19 +636,7 @@ static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
 	new->protocol = htons(ETH_P_IPV6);
 	new->pkt_type = PACKET_HOST;
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(entry, &lowpan_devices, list)
-		if (lowpan_dev_info(entry->ldev)->real_dev == new->dev) {
-			skb = skb_copy(new, GFP_ATOMIC);
-			if (!skb) {
-				stat = -ENOMEM;
-				break;
-			}
-
-			skb->dev = entry->ldev;
-			stat = netif_rx(skb);
-		}
-	rcu_read_unlock();
+	stat = lowpan_give_skb_to_devices(new);
 
 	kfree_skb(new);
 
-- 
1.7.11.2

[PATCH 2/2] 6lowpan: Handle uncompressed IPv6 packets over 6LoWPAN

[Alan Ott]

Handle the reception of uncompressed packets (dispatch type = IPv6).

Signed-off-by: Alan Ott <alan@signal11.us>
---
 net/ieee802154/6lowpan.c | 41 ++++++++++++++++++++++++++++++++---------
 1 file changed, 32 insertions(+), 9 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 1714cfa..43bd1c0 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -1147,19 +1147,42 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
 		goto drop;
 
 	/* check that it's our buffer */
-	switch (skb->data[0] & 0xe0) {
-	case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
-	case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
-	case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
-		local_skb = skb_clone(skb, GFP_ATOMIC);
+	if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
+		/* Copy the packet so that the IPv6 header is
+		 * properly aligned.
+		 */
+		local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
+						skb_tailroom(skb), GFP_ATOMIC);
 		if (!local_skb)
 			goto drop;
-		lowpan_process_data(local_skb);
 
+		local_skb->protocol = htons(ETH_P_IPV6);
+		local_skb->pkt_type = PACKET_HOST;
+
+		/* Pull off the 1-byte of 6lowpan header. */
+		skb_pull(local_skb, 1);
+		skb_reset_network_header(local_skb);
+		skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
+
+		lowpan_give_skb_to_devices(local_skb);
+
+		kfree_skb(local_skb);
 		kfree_skb(skb);
-		break;
-	default:
-		break;
+	} else {
+		switch (skb->data[0] & 0xe0) {
+		case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
+		case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
+		case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
+			local_skb = skb_clone(skb, GFP_ATOMIC);
+			if (!local_skb)
+				goto drop;
+			lowpan_process_data(local_skb);
+
+			kfree_skb(skb);
+			break;
+		default:
+			break;
+		}
 	}
 
 	return NET_RX_SUCCESS;
-- 
1.7.11.2

Re: [PATCH 2/2] 6lowpan: Handle uncompressed IPv6 packets over 6LoWPAN

[David Miller]

From: Alan Ott <alan@signal11.us>
Date: Wed, 16 Jan 2013 00:43:57 -0500

> +		local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
> +						skb_tailroom(skb), GFP_ATOMIC);

This is not indented properly.

When a function call spans multiple lines, the second and subsequent
lines should be indented to the column right after the openning
parenthesis of the call itself, using a combination of TAB and
SPC characters as needed.

Re: [PATCH 2/2] 6lowpan: Handle uncompressed IPv6 packets over 6LoWPAN

[Alan Ott]

On 01/16/2013 04:22 PM, David Miller wrote:
> From: Alan Ott <alan@signal11.us>
> Date: Wed, 16 Jan 2013 00:43:57 -0500
>
>> +		local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
>> +						skb_tailroom(skb), GFP_ATOMIC);
> This is not indented properly.
>
> When a function call spans multiple lines, the second and subsequent
> lines should be indented to the column right after the openning
> parenthesis of the call itself, using a combination of TAB and
> SPC characters as needed.

Thanks David, I'll fix and re-submit.

Alan.

[PATCH v2 0/2] Handle Uncompressed IPv6 on 6LoWPAN

[Alan Ott]

This has been tested by exchanging data with with the Contiki operating
system using a Redwire Econotag.  Contiki had to be set to send uncompressed
data, and had to have a #define modified to enable reception and processing
of header-compressed packets when not set to send compressed data.

Version 2 fixes a format issue pointed out by David Miller.

Alan Ott (2):
  6lowpan: Refactor packet delivery into a function
  6lowpan: Handle uncompressed IPv6 packets over 6LoWPAN

 net/ieee802154/6lowpan.c | 79 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 56 insertions(+), 23 deletions(-)

-- 
1.7.11.2

[PATCH v2 1/2] 6lowpan: Refactor packet delivery into a function

[Alan Ott]

Refactor the handing of the skb's to the individual lowpan devices into a
function.

Signed-off-by: Alan Ott <alan@signal11.us>
---
 net/ieee802154/6lowpan.c | 38 ++++++++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 14 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index f651da6..1714cfa 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -594,10 +594,32 @@ static int lowpan_header_create(struct sk_buff *skb,
 	}
 }
 
+static int lowpan_give_skb_to_devices(struct sk_buff *skb)
+{
+	struct lowpan_dev_record *entry;
+	struct sk_buff *skb_cp;
+	int stat = NET_RX_SUCCESS;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(entry, &lowpan_devices, list)
+		if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
+			skb_cp = skb_copy(skb, GFP_ATOMIC);
+			if (!skb_cp) {
+				stat = -ENOMEM;
+				break;
+			}
+
+			skb_cp->dev = entry->ldev;
+			stat = netif_rx(skb_cp);
+		}
+	rcu_read_unlock();
+
+	return stat;
+}
+
 static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
 {
 	struct sk_buff *new;
-	struct lowpan_dev_record *entry;
 	int stat = NET_RX_SUCCESS;
 
 	new = skb_copy_expand(skb, sizeof(struct ipv6hdr), skb_tailroom(skb),
@@ -614,19 +636,7 @@ static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
 	new->protocol = htons(ETH_P_IPV6);
 	new->pkt_type = PACKET_HOST;
 
-	rcu_read_lock();
-	list_for_each_entry_rcu(entry, &lowpan_devices, list)
-		if (lowpan_dev_info(entry->ldev)->real_dev == new->dev) {
-			skb = skb_copy(new, GFP_ATOMIC);
-			if (!skb) {
-				stat = -ENOMEM;
-				break;
-			}
-
-			skb->dev = entry->ldev;
-			stat = netif_rx(skb);
-		}
-	rcu_read_unlock();
+	stat = lowpan_give_skb_to_devices(new);
 
 	kfree_skb(new);
 
-- 
1.7.11.2

[PATCH v2 2/2] 6lowpan: Handle uncompressed IPv6 packets over 6LoWPAN

[Alan Ott]

Handle the reception of uncompressed packets (dispatch type = IPv6).

Signed-off-by: Alan Ott <alan@signal11.us>
---
 net/ieee802154/6lowpan.c | 41 ++++++++++++++++++++++++++++++++---------
 1 file changed, 32 insertions(+), 9 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 1714cfa..09cba81 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -1147,19 +1147,42 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
 		goto drop;
 
 	/* check that it's our buffer */
-	switch (skb->data[0] & 0xe0) {
-	case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
-	case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
-	case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
-		local_skb = skb_clone(skb, GFP_ATOMIC);
+	if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
+		/* Copy the packet so that the IPv6 header is
+		 * properly aligned.
+		 */
+		local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
+					    skb_tailroom(skb), GFP_ATOMIC);
 		if (!local_skb)
 			goto drop;
-		lowpan_process_data(local_skb);
 
+		local_skb->protocol = htons(ETH_P_IPV6);
+		local_skb->pkt_type = PACKET_HOST;
+
+		/* Pull off the 1-byte of 6lowpan header. */
+		skb_pull(local_skb, 1);
+		skb_reset_network_header(local_skb);
+		skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
+
+		lowpan_give_skb_to_devices(local_skb);
+
+		kfree_skb(local_skb);
 		kfree_skb(skb);
-		break;
-	default:
-		break;
+	} else {
+		switch (skb->data[0] & 0xe0) {
+		case LOWPAN_DISPATCH_IPHC:	/* ipv6 datagram */
+		case LOWPAN_DISPATCH_FRAG1:	/* first fragment header */
+		case LOWPAN_DISPATCH_FRAGN:	/* next fragments headers */
+			local_skb = skb_clone(skb, GFP_ATOMIC);
+			if (!local_skb)
+				goto drop;
+			lowpan_process_data(local_skb);
+
+			kfree_skb(skb);
+			break;
+		default:
+			break;
+		}
 	}
 
 	return NET_RX_SUCCESS;
-- 
1.7.11.2

Re: [PATCH v2 1/2] 6lowpan: Refactor packet delivery into a function

[David Miller]

From: Alan Ott <alan@signal11.us>
Date: Thu, 17 Jan 2013 00:09:47 -0500

> Refactor the handing of the skb's to the individual lowpan devices into a
> function.
> 
> Signed-off-by: Alan Ott <alan@signal11.us>

Applied.

Re: [PATCH v2 2/2] 6lowpan: Handle uncompressed IPv6 packets over 6LoWPAN

[David Miller]

From: Alan Ott <alan@signal11.us>
Date: Thu, 17 Jan 2013 00:09:48 -0500

> Handle the reception of uncompressed packets (dispatch type = IPv6).
> 
> Signed-off-by: Alan Ott <alan@signal11.us>

Applied.