[PATCH v2 net-next 00/12] 6lowpan: Some more bug fixes

[PATCH v2 net-next 00/12] 6lowpan: Some more bug fixes

[Tony Cheneau]

Hello,

This patchset fixes serious bugs within the 6LoWPAN modules. I wrote a script
(available at [1]) to prove the issues are real.  One can try and see that
without these patches, most of the test fail (e.g. packet dropped by the
receiver or node crashing). With all patches applied, all tests succeed. The
tests themselves are very basic: sending ICMP packets, sending UDP packets,
sending TCP packets, varying size of the packets. This actually triggers some
6LoWPAN specific code, namely fragmentation, packet reassembly and header
compression.

This code passed the checkpatch.pl tool with a few warnings, that I believe
are OK. It should apply cleanly on the latest net-next.

Regards,
	Tony Cheneau

[1]: https://github.com/tcheneau/linux802154-regression-tests

Tony Cheneau (12):
  6lowpan: lowpan_is_iid_16_bit_compressable() does not detect
    compressible address correctly
  6lowpan: next header is not properly set upon decompression of a UDP
    header.
  6lowpan: always enable link-layer acknowledgments
  mac802154: turn on ACK when enabled by the upper layers
  6lowpan: use short IEEE 802.15.4 addresses for broadcast destination
  6lowpan: fix first fragment (FRAG1) handling
  6lowpan: add debug messages for 6LoWPAN fragmentation
  6lowpan: store fragment tag values per device instead of net stack
    wide
  mac802154: re-introduce mac802154_dev_get_dsn()
  6lowpan: obtain IEEE802.15.4 sequence number from the MAC layer
  6lowpan: use the PANID provided by the device instead of a static
    value
  6lowpan: modify udp compression/uncompression to match the standard

 net/ieee802154/6lowpan.c  | 136 +++++++++++++++++++++++++++++++++++++---------
 net/ieee802154/6lowpan.h  |   7 ++-
 net/mac802154/mac802154.h |   1 +
 net/mac802154/mac_cmd.c   |   1 +
 net/mac802154/mib.c       |   9 +++
 net/mac802154/wpan.c      |   2 +
 6 files changed, 127 insertions(+), 29 deletions(-)

-- 
1.7.12.4


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[PATCH v2 net-next 01/12] 6lowpan: lowpan_is_iid_16_bit_compressable() does not detect compressible address correctly

[Tony Cheneau]

The current test is not RFC6282 compliant. The same issue has been found
and fixed in Contiki. This patch is basically a port of their fix.

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/ieee802154/6lowpan.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/ieee802154/6lowpan.h b/net/ieee802154/6lowpan.h
index bba5f83..4b8f917 100644
--- a/net/ieee802154/6lowpan.h
+++ b/net/ieee802154/6lowpan.h
@@ -92,9 +92,10 @@
  */
 #define lowpan_is_iid_16_bit_compressable(a)	\
 	((((a)->s6_addr16[4]) == 0) &&		\
-	 (((a)->s6_addr16[5]) == 0) &&		\
-	 (((a)->s6_addr16[6]) == 0) &&		\
-	 ((((a)->s6_addr[14]) & 0x80) == 0))
+	 (((a)->s6_addr[10]) == 0) &&		\
+	 (((a)->s6_addr[11]) == 0xff) &&	\
+	 (((a)->s6_addr[12]) == 0xfe) &&	\
+	 (((a)->s6_addr[13]) == 0))
 
 /* multicast address */
 #define is_addr_mcast(a) (((a)->s6_addr[0]) == 0xFF)
-- 
1.7.12.4


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[PATCH v2 net-next 02/12] 6lowpan: next header is not properly set upon decompression of a UDP header.

[Tony Cheneau]

This causes a drop of the UDP packet.

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/ieee802154/6lowpan.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 43b95ca..9f53904 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -918,9 +918,11 @@ lowpan_process_data(struct sk_buff *skb)
 	}
 
 	/* UDP data uncompression */
-	if (iphc0 & LOWPAN_IPHC_NH_C)
+	if (iphc0 & LOWPAN_IPHC_NH_C) {
 		if (lowpan_uncompress_udp_header(skb))
 			goto drop;
+		hdr.nexthdr = UIP_PROTO_UDP;
+	}
 
 	/* Not fragmented package */
 	hdr.payload_len = htons(skb->len);
-- 
1.7.12.4


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[PATCH v2 net-next 03/12] 6lowpan: always enable link-layer acknowledgments

[Tony Cheneau]

This feature is especially important when using fragmentation, because
the reassembly mechanism cannot recover from the loss of a fragment.

Note that some hardware ignore this flag and not will not transmit
acknowledgments even if this is set.

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/ieee802154/6lowpan.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 9f53904..e7f61de 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -584,6 +584,10 @@ static int lowpan_header_create(struct sk_buff *skb,
 
 		mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
 
+		/* request acknowledgment when possible */
+		if (!lowpan_is_addr_broadcast(daddr))
+			mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
+
 		return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
 				type, (void *)&da, (void *)&sa, skb->len);
 	}
-- 
1.7.12.4


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[PATCH v2 net-next 04/12] mac802154: turn on ACK when enabled by the upper layers

[Tony Cheneau]

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/mac802154/wpan.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/mac802154/wpan.c b/net/mac802154/wpan.c
index d20c6d3..7d3f659 100644
--- a/net/mac802154/wpan.c
+++ b/net/mac802154/wpan.c
@@ -145,6 +145,8 @@ static int mac802154_header_create(struct sk_buff *skb,
 
 	head[pos++] = mac_cb(skb)->seq; /* DSN/BSN */
 	fc = mac_cb_type(skb);
+	if (mac_cb_is_ackreq(skb))
+		fc |= IEEE802154_FC_ACK_REQ;
 
 	if (!saddr) {
 		spin_lock_bh(&priv->mib_lock);
-- 
1.7.12.4


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[PATCH v2 net-next 05/12] 6lowpan: use short IEEE 802.15.4 addresses for broadcast destination

[Tony Cheneau]

The IEEE 802.15.4 standard uses the 0xFFFF short address (2 bytes) for message
broadcasting.

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/ieee802154/6lowpan.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index e7f61de..0eebb96 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -572,21 +572,28 @@ static int lowpan_header_create(struct sk_buff *skb,
 	 * this isn't implemented in mainline yet, so currently we assign 0xff
 	 */
 	{
+		mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
+
 		/* prepare wpan address data */
 		sa.addr_type = IEEE802154_ADDR_LONG;
 		sa.pan_id = 0xff;
-
-		da.addr_type = IEEE802154_ADDR_LONG;
-		da.pan_id = 0xff;
-
-		memcpy(&(da.hwaddr), daddr, 8);
 		memcpy(&(sa.hwaddr), saddr, 8);
 
-		mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
+		da.pan_id = 0xff;
+		/*
+		 * if the destination address is the broadcast address, use the
+		 * corresponding short address
+		 */
+		if (lowpan_is_addr_broadcast(daddr)) {
+			da.addr_type = IEEE802154_ADDR_SHORT;
+			da.short_addr = IEEE802154_ADDR_BROADCAST;
+		} else {
+			da.addr_type = IEEE802154_ADDR_LONG;
+			memcpy(&(da.hwaddr), daddr, 8);
 
-		/* request acknowledgment when possible */
-		if (!lowpan_is_addr_broadcast(daddr))
+			/* request acknowledgment */
 			mac_cb(skb)->flags |= MAC_CB_FLAG_ACKREQ;
+		}
 
 		return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
 				type, (void *)&da, (void *)&sa, skb->len);
-- 
1.7.12.4


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Re: [Linux-zigbee-devel] [PATCH v2 net-next 05/12] 6lowpan: use short IEEE 802.15.4 addresses for broadcast destination

[Alexander Aring]

Hi Tony,

On Mon, Mar 25, 2013 at 11:59:25PM -0400, Tony Cheneau wrote:
> The IEEE 802.15.4 standard uses the 0xFFFF short address (2 bytes) for message
> broadcasting.
> 
> Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
> ---
>  net/ieee802154/6lowpan.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
> index e7f61de..0eebb96 100644
> --- a/net/ieee802154/6lowpan.c
> +++ b/net/ieee802154/6lowpan.c
> @@ -572,21 +572,28 @@ static int lowpan_header_create(struct sk_buff *skb,
>  	 * this isn't implemented in mainline yet, so currently we assign 0xff
>  	 */
>  	{
> +		mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
> +
>  		/* prepare wpan address data */
>  		sa.addr_type = IEEE802154_ADDR_LONG;
>  		sa.pan_id = 0xff;
> -
> -		da.addr_type = IEEE802154_ADDR_LONG;
> -		da.pan_id = 0xff;
> -
> -		memcpy(&(da.hwaddr), daddr, 8);
>  		memcpy(&(sa.hwaddr), saddr, 8);
>  
> -		mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
> +		da.pan_id = 0xff;
> +		/*
> +		 * if the destination address is the broadcast address, use the
> +		 * corresponding short address
> +		 */
> +		if (lowpan_is_addr_broadcast(daddr)) {
> +			da.addr_type = IEEE802154_ADDR_SHORT;
> +			da.short_addr = IEEE802154_ADDR_BROADCAST;
> +		} else {
> +			da.addr_type = IEEE802154_ADDR_LONG;
> +			memcpy(&(da.hwaddr), daddr, 8);

It's some nitpick here.
Maybe it's better to use IEEE802154_ADDR_LEN instead of 8.

I mean we have this define, and we should use it if we mean the
ieee802154 address length.

Alex

[PATCH v2 net-next 06/12] 6lowpan: fix first fragment (FRAG1) handling

[Tony Cheneau]

The first fragment, FRAG1, must contain some payload according to the
specs. However, as it is currently written, the first fragment will
remain empty and only contain the 6lowpan headers.

This patch also extracts the transport layer information from the first
fragment. This information is used later on when uncompressing UDP
header.

Thanks to Wolf-Bastian Pöttner for noticing that the offset value was
not properly initialized.

Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
---
 net/ieee802154/6lowpan.c | 36 +++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 0eebb96..4a62289 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -661,7 +661,7 @@ static void lowpan_fragment_timer_expired(unsigned long entry_addr)
 }
 
 static struct lowpan_fragment *
-lowpan_alloc_new_frame(struct sk_buff *skb, u8 len, u16 tag)
+lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag)
 {
 	struct lowpan_fragment *frame;
 
@@ -731,7 +731,7 @@ lowpan_process_data(struct sk_buff *skb)
 	{
 		struct lowpan_fragment *frame;
 		/* slen stores the rightmost 8 bits of the 11 bits length */
-		u8 slen, offset;
+		u8 slen, offset = 0;
 		u16 len, tag;
 		bool found = false;
 
@@ -742,6 +742,12 @@ lowpan_process_data(struct sk_buff *skb)
 		/* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
 		len = ((iphc0 & 7) << 8) | slen;
 
+		/* FRAGN */
+		if ((iphc0 & LOWPAN_DISPATCH_MASK) != LOWPAN_DISPATCH_FRAG1) {
+			if (lowpan_fetch_skb_u8(skb, &offset))
+				goto unlock_and_drop;
+		}
+
 		/*
 		 * check if frame assembling with the same tag is
 		 * already in progress
@@ -761,12 +767,6 @@ lowpan_process_data(struct sk_buff *skb)
 				goto unlock_and_drop;
 		}
 
-		if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1)
-			goto unlock_and_drop;
-
-		if (lowpan_fetch_skb_u8(skb, &offset)) /* fetch offset */
-			goto unlock_and_drop;
-
 		/* if payload fits buffer, copy it */
 		if (likely((offset * 8 + skb->len) <= frame->length))
 			skb_copy_to_linear_data_offset(frame->skb, offset * 8,
@@ -982,13 +982,13 @@ static int lowpan_get_mac_header_length(struct sk_buff *skb)
 
 static int
 lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
-			int mlen, int plen, int offset)
+			int mlen, int plen, int offset, int type)
 {
 	struct sk_buff *frag;
 	int hlen, ret;
 
-	/* if payload length is zero, therefore it's a first fragment */
-	hlen = (plen == 0 ? LOWPAN_FRAG1_HEAD_SIZE :  LOWPAN_FRAGN_HEAD_SIZE);
+	hlen = (type == LOWPAN_DISPATCH_FRAG1) ?
+			LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE;
 
 	lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
 
@@ -1031,7 +1031,13 @@ lowpan_skb_fragmentation(struct sk_buff *skb)
 	head[2] = tag >> 8;
 	head[3] = tag & 0xff;
 
-	err = lowpan_fragment_xmit(skb, head, header_length, 0, 0);
+	err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
+				   0, LOWPAN_DISPATCH_FRAG1);
+
+	if (err)
+		goto exit;
+
+	offset = LOWPAN_FRAG_SIZE;
 
 	/* next fragment header */
 	head[0] &= ~LOWPAN_DISPATCH_FRAG1;
@@ -1046,10 +1052,14 @@ lowpan_skb_fragmentation(struct sk_buff *skb)
 			len = payload_length - offset;
 
 		err = lowpan_fragment_xmit(skb, head, header_length,
-							len, offset);
+					   len, offset, LOWPAN_DISPATCH_FRAGN);
+		if (err)
+			goto exit;
+
 		offset += len;
 	}
 
+exit:
 	return err;
 }
 
-- 
1.7.12.4


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[PATCH v2 net-next 07/12] 6lowpan: add debug messages for 6LoWPAN fragmentation

[Tony Cheneau]

Add pr_debug() call in order to debug 6LoWPAN fragmentation and
reassembly.

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/ieee802154/6lowpan.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 4a62289..61eee9d 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -742,10 +742,16 @@ lowpan_process_data(struct sk_buff *skb)
 		/* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */
 		len = ((iphc0 & 7) << 8) | slen;
 
-		/* FRAGN */
-		if ((iphc0 & LOWPAN_DISPATCH_MASK) != LOWPAN_DISPATCH_FRAG1) {
+		if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) {
+			pr_debug("%s received a FRAG1 packet (tag: %d, "
+				 "size of the entire IP packet: %d)",
+				 __func__, tag, len);
+		} else { /* FRAGN */
 			if (lowpan_fetch_skb_u8(skb, &offset))
 				goto unlock_and_drop;
+			pr_debug("%s received a FRAGN packet (tag: %d, "
+				 "size of the entire IP packet: %d, "
+				 "offset: %d)", __func__, tag, len, offset * 8);
 		}
 
 		/*
@@ -762,6 +768,8 @@ lowpan_process_data(struct sk_buff *skb)
 
 		/* alloc new frame structure */
 		if (!found) {
+			pr_debug("%s first fragment received for tag %d, "
+				 "begin packet reassembly", __func__, tag);
 			frame = lowpan_alloc_new_frame(skb, len, tag);
 			if (!frame)
 				goto unlock_and_drop;
@@ -784,6 +792,9 @@ lowpan_process_data(struct sk_buff *skb)
 			list_del(&frame->list);
 			spin_unlock_bh(&flist_lock);
 
+			pr_debug("%s successfully reassembled fragment "
+				 "(tag %d)", __func__, tag);
+
 			dev_kfree_skb(skb);
 			skb = frame->skb;
 			kfree(frame);
@@ -1034,8 +1045,11 @@ lowpan_skb_fragmentation(struct sk_buff *skb)
 	err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE,
 				   0, LOWPAN_DISPATCH_FRAG1);
 
-	if (err)
+	if (err) {
+		pr_debug("%s unable to send FRAG1 packet (tag: %d)",
+			 __func__, tag);
 		goto exit;
+	}
 
 	offset = LOWPAN_FRAG_SIZE;
 
@@ -1053,8 +1067,11 @@ lowpan_skb_fragmentation(struct sk_buff *skb)
 
 		err = lowpan_fragment_xmit(skb, head, header_length,
 					   len, offset, LOWPAN_DISPATCH_FRAGN);
-		if (err)
+		if (err) {
+			pr_debug("%s unable to send a subsequent FRAGN packet "
+				 "(tag: %d, offset: %d", __func__, tag, offset);
 			goto exit;
+		}
 
 		offset += len;
 	}
-- 
1.7.12.4


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[PATCH v2 net-next 08/12] 6lowpan: store fragment tag values per device instead of net stack wide

[Tony Cheneau]

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/ieee802154/6lowpan.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 61eee9d..f952451 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -104,6 +104,7 @@ static const u8 lowpan_llprefix[] = {0xfe, 0x80};
 struct lowpan_dev_info {
 	struct net_device	*real_dev; /* real WPAN device ptr */
 	struct mutex		dev_list_mtx; /* mutex for list ops */
+	unsigned short fragment_tag;
 };
 
 struct lowpan_dev_record {
@@ -120,7 +121,6 @@ struct lowpan_fragment {
 	struct list_head	list;		/* fragments list */
 };
 
-static unsigned short fragment_tag;
 static LIST_HEAD(lowpan_fragments);
 static DEFINE_SPINLOCK(flist_lock);
 
@@ -1027,14 +1027,14 @@ lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
 }
 
 static int
-lowpan_skb_fragmentation(struct sk_buff *skb)
+lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev)
 {
 	int  err, header_length, payload_length, tag, offset = 0;
 	u8 head[5];
 
 	header_length = lowpan_get_mac_header_length(skb);
 	payload_length = skb->len - header_length;
-	tag = fragment_tag++;
+	tag = lowpan_dev_info(dev)->fragment_tag++;
 
 	/* first fragment header */
 	head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7);
@@ -1099,7 +1099,7 @@ static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 	pr_debug("frame is too big, fragmentation is needed\n");
-	err = lowpan_skb_fragmentation(skb);
+	err = lowpan_skb_fragmentation(skb, dev);
 error:
 	dev_kfree_skb(skb);
 out:
@@ -1243,6 +1243,7 @@ static int lowpan_newlink(struct net *src_net, struct net_device *dev,
 		return -ENODEV;
 
 	lowpan_dev_info(dev)->real_dev = real_dev;
+	lowpan_dev_info(dev)->fragment_tag = 0;
 	mutex_init(&lowpan_dev_info(dev)->dev_list_mtx);
 
 	entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL);
-- 
1.7.12.4


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Re: [PATCH v2 net-next 08/12] 6lowpan: store fragment tag values per device instead of net stack wide

[Sergei Shtylyov]

Hello.

On 26-03-2013 7:59, Tony Cheneau wrote:

> Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org>
> ---
>   net/ieee802154/6lowpan.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)

> diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
> index 61eee9d..f952451 100644
> --- a/net/ieee802154/6lowpan.c
> +++ b/net/ieee802154/6lowpan.c
> @@ -104,6 +104,7 @@ static const u8 lowpan_llprefix[] = {0xfe, 0x80};
>   struct lowpan_dev_info {
>   	struct net_device	*real_dev; /* real WPAN device ptr */
>   	struct mutex		dev_list_mtx; /* mutex for list ops */
> +	unsigned short fragment_tag;

    Small formatting nit: align field name with the others above please.

WBR, Sergei

[PATCH v2 net-next 09/12] mac802154: add mac802154_dev_get_dsn()

[Tony Cheneau]

Bring-over mac802154_dev_get_dsn() function that was present in the
Linux ZigBee kernel. This function is called by the 6LoWPAN code in
order to properly set the DSN (Data Sequence Number) value in the IEEE
802.15.4 frame.

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/mac802154/mac802154.h | 1 +
 net/mac802154/mac_cmd.c   | 1 +
 net/mac802154/mib.c       | 9 +++++++++
 3 files changed, 11 insertions(+)

diff --git a/net/mac802154/mac802154.h b/net/mac802154/mac802154.h
index a4dcaf1..21fa386 100644
--- a/net/mac802154/mac802154.h
+++ b/net/mac802154/mac802154.h
@@ -114,5 +114,6 @@ void mac802154_dev_set_ieee_addr(struct net_device *dev);
 u16 mac802154_dev_get_pan_id(const struct net_device *dev);
 void mac802154_dev_set_pan_id(struct net_device *dev, u16 val);
 void mac802154_dev_set_page_channel(struct net_device *dev, u8 page, u8 chan);
+u8 mac802154_dev_get_dsn(const struct net_device *dev);
 
 #endif /* MAC802154_H */
diff --git a/net/mac802154/mac_cmd.c b/net/mac802154/mac_cmd.c
index d8d2770..a99910d 100644
--- a/net/mac802154/mac_cmd.c
+++ b/net/mac802154/mac_cmd.c
@@ -73,4 +73,5 @@ struct ieee802154_mlme_ops mac802154_mlme_wpan = {
 	.start_req = mac802154_mlme_start_req,
 	.get_pan_id = mac802154_dev_get_pan_id,
 	.get_short_addr = mac802154_dev_get_short_addr,
+	.get_dsn = mac802154_dev_get_dsn,
 };
diff --git a/net/mac802154/mib.c b/net/mac802154/mib.c
index f47781a..f03e55f 100644
--- a/net/mac802154/mib.c
+++ b/net/mac802154/mib.c
@@ -159,6 +159,15 @@ void mac802154_dev_set_pan_id(struct net_device *dev, u16 val)
 	}
 }
 
+u8 mac802154_dev_get_dsn(const struct net_device *dev)
+{
+	struct mac802154_sub_if_data *priv = netdev_priv(dev);
+
+	BUG_ON(dev->type != ARPHRD_IEEE802154);
+
+	return priv->dsn++;
+}
+
 static void phy_chan_notify(struct work_struct *work)
 {
 	struct phy_chan_notify_work *nw = container_of(work,
-- 
1.7.12.4


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[PATCH v2 net-next 10/12] 6lowpan: obtain IEEE802.15.4 sequence number from the MAC layer

[Tony Cheneau]

Sets the sequence number in the frame format. Without this fix, the sequence
number is always set to 0. This makes trafic analysis very hard.

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/ieee802154/6lowpan.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index f952451..d1d4ee6 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -573,6 +573,7 @@ static int lowpan_header_create(struct sk_buff *skb,
 	 */
 	{
 		mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
+		mac_cb(skb)->seq = ieee802154_mlme_ops(dev)->get_dsn(dev);
 
 		/* prepare wpan address data */
 		sa.addr_type = IEEE802154_ADDR_LONG;
@@ -1127,6 +1128,12 @@ static u16 lowpan_get_short_addr(const struct net_device *dev)
 	return ieee802154_mlme_ops(real_dev)->get_short_addr(real_dev);
 }
 
+static u8 lowpan_get_dsn(const struct net_device *dev)
+{
+	struct net_device *real_dev = lowpan_dev_info(dev)->real_dev;
+	return ieee802154_mlme_ops(real_dev)->get_dsn(real_dev);
+}
+
 static struct header_ops lowpan_header_ops = {
 	.create	= lowpan_header_create,
 };
@@ -1140,6 +1147,7 @@ static struct ieee802154_mlme_ops lowpan_mlme = {
 	.get_pan_id = lowpan_get_pan_id,
 	.get_phy = lowpan_get_phy,
 	.get_short_addr = lowpan_get_short_addr,
+	.get_dsn = lowpan_get_dsn,
 };
 
 static void lowpan_setup(struct net_device *dev)
-- 
1.7.12.4


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[PATCH v2 net-next 11/12] 6lowpan: use the PANID provided by the device instead of a static value

[Tony Cheneau]

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/ieee802154/6lowpan.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index d1d4ee6..276971b 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -577,10 +577,12 @@ static int lowpan_header_create(struct sk_buff *skb,
 
 		/* prepare wpan address data */
 		sa.addr_type = IEEE802154_ADDR_LONG;
-		sa.pan_id = 0xff;
+		sa.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
+
 		memcpy(&(sa.hwaddr), saddr, 8);
+		/* intra-PAN communications */
+		da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev);
 
-		da.pan_id = 0xff;
 		/*
 		 * if the destination address is the broadcast address, use the
 		 * corresponding short address
-- 
1.7.12.4


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[PATCH v2 net-next 12/12] 6lowpan: modify udp compression/uncompression to match the standard

[Tony Cheneau]

The previous code would just compress the UDP header and send the compressed
UDP header along with the uncompressed one.

Signed-off-by: Tony Cheneau <tony.cheneau-jNfjcPZKvDhg9hUCZPvPmw@public.gmane.org>
---
 net/ieee802154/6lowpan.c | 39 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 276971b..c9c3f3d 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -284,6 +284,9 @@ lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
 	/* checksum is always inline */
 	memcpy(*hc06_ptr, &uh->check, 2);
 	*hc06_ptr += 2;
+
+	/* skip the UDP header */
+	skb_pull(skb, sizeof(struct udphdr));
 }
 
 static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
@@ -309,9 +312,8 @@ static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
 }
 
 static int
-lowpan_uncompress_udp_header(struct sk_buff *skb)
+lowpan_uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
 {
-	struct udphdr *uh = udp_hdr(skb);
 	u8 tmp;
 
 	if (!uh)
@@ -358,6 +360,14 @@ lowpan_uncompress_udp_header(struct sk_buff *skb)
 		/* copy checksum */
 		memcpy(&uh->check, &skb->data[0], 2);
 		skb_pull(skb, 2);
+
+		/*
+		 * UDP lenght needs to be infered from the lower layers
+		 * here, we obtain the hint from the remaining size of the
+		 * frame
+		 */
+		uh->len = htons(skb->len + sizeof(struct udphdr));
+		pr_debug("uncompressed UDP length: src = %d", uh->len);
 	} else {
 		pr_debug("ERROR: unsupported NH format\n");
 		goto err;
@@ -944,8 +954,31 @@ lowpan_process_data(struct sk_buff *skb)
 
 	/* UDP data uncompression */
 	if (iphc0 & LOWPAN_IPHC_NH_C) {
-		if (lowpan_uncompress_udp_header(skb))
+		struct udphdr uh;
+		struct sk_buff *new;
+		if (lowpan_uncompress_udp_header(skb, &uh))
 			goto drop;
+
+		/*
+		 * replace the compressed UDP head by the uncompressed UDP
+		 * header
+		 */
+		new = skb_copy_expand(skb, sizeof(struct udphdr),
+				      skb_tailroom(skb), GFP_ATOMIC);
+		kfree_skb(skb);
+
+		if (!new)
+			return -ENOMEM;
+
+		skb = new;
+
+		skb_push(skb, sizeof(struct udphdr));
+		skb_reset_transport_header(skb);
+		skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
+
+		lowpan_raw_dump_table(__func__, "raw UDP header dump",
+				      (u8 *)&uh, sizeof(uh));
+
 		hdr.nexthdr = UIP_PROTO_UDP;
 	}
 
-- 
1.7.12.4


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Re: [PATCH v2 net-next 00/12] 6lowpan: Some more bug fixes

[Alan Ott]

On 03/25/2013 11:59 PM, Tony Cheneau wrote:
> This patchset fixes serious bugs within the 6LoWPAN modules. I wrote a script
> (available at [1]) to prove the issues are real.  One can try and see that
> without these patches, most of the test fail (e.g. packet dropped by the
> receiver or node crashing). With all patches applied, all tests succeed. The
> tests themselves are very basic: sending ICMP packets, sending UDP packets,
> sending TCP packets, varying size of the packets. This actually triggers some
> 6LoWPAN specific code, namely fragmentation, packet reassembly and header
> compression.
> 
> This code passed the checkpatch.pl tool with a few warnings, that I believe
> are OK. It should apply cleanly on the latest net-next.
> 

I and have been running some form of this patchset since October, and
have reviewed it several times.

Reviewed-by: Alan Ott <alan@signal11.us>
Tested-by: Alan Ott <alan@signal11.us>


> Regards,
> 	Tony Cheneau
> 
> [1]: https://github.com/tcheneau/linux802154-regression-tests
> 
> Tony Cheneau (12):
>   6lowpan: lowpan_is_iid_16_bit_compressable() does not detect
>     compressible address correctly
>   6lowpan: next header is not properly set upon decompression of a UDP
>     header.
>   6lowpan: always enable link-layer acknowledgments
>   mac802154: turn on ACK when enabled by the upper layers
>   6lowpan: use short IEEE 802.15.4 addresses for broadcast destination
>   6lowpan: fix first fragment (FRAG1) handling
>   6lowpan: add debug messages for 6LoWPAN fragmentation
>   6lowpan: store fragment tag values per device instead of net stack
>     wide
>   mac802154: re-introduce mac802154_dev_get_dsn()
>   6lowpan: obtain IEEE802.15.4 sequence number from the MAC layer
>   6lowpan: use the PANID provided by the device instead of a static
>     value
>   6lowpan: modify udp compression/uncompression to match the standard
> 
>  net/ieee802154/6lowpan.c  | 136 +++++++++++++++++++++++++++++++++++++---------
>  net/ieee802154/6lowpan.h  |   7 ++-
>  net/mac802154/mac802154.h |   1 +
>  net/mac802154/mac_cmd.c   |   1 +
>  net/mac802154/mib.c       |   9 +++
>  net/mac802154/wpan.c      |   2 +
>  6 files changed, 127 insertions(+), 29 deletions(-)
> 

Re: [PATCH v2 net-next 00/12] 6lowpan: Some more bug fixes

[David Miller]

From: Tony Cheneau <tony.cheneau@amnesiak.org>
Date: Mon, 25 Mar 2013 23:59:20 -0400

> This patchset fixes serious bugs within the 6LoWPAN modules. I wrote a script
> (available at [1]) to prove the issues are real.  One can try and see that
> without these patches, most of the test fail (e.g. packet dropped by the
> receiver or node crashing). With all patches applied, all tests succeed. The
> tests themselves are very basic: sending ICMP packets, sending UDP packets,
> sending TCP packets, varying size of the packets. This actually triggers some
> 6LoWPAN specific code, namely fragmentation, packet reassembly and header
> compression.
> 
> This code passed the checkpatch.pl tool with a few warnings, that I believe
> are OK. It should apply cleanly on the latest net-next.

Series applied, thanks.