6lowpan: add support for 802.15.4 short addr handling

This patch adds necessary handling for use the short address for
802.15.4 6lowpan. It contains support for IPHC address compression
and new matching algorithmn to decide which link layer address will be
used for 802.15.4 frame.

Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 57 insertions, 56 deletions

diff --git a/net/ieee802154/6lowpan/tx.c b/net/ieee802154/6lowpan/tx.c
index e459afd16bb3..dbb476d7d38f 100644
--- a/net/ieee802154/6lowpan/tx.c
+++ b/net/ieee802154/6lowpan/tx.c
@@ -9,6 +9,7 @@
  */
 
 #include <net/6lowpan.h>
+#include <net/ndisc.h>
 #include <net/ieee802154_netdev.h>
 #include <net/mac802154.h>
 
@@ -17,19 +18,9 @@
 #define LOWPAN_FRAG1_HEAD_SIZE	0x4
 #define LOWPAN_FRAGN_HEAD_SIZE	0x5
 
-/* don't save pan id, it's intra pan */
-struct lowpan_addr {
-	u8 mode;
-	union {
-		/* IPv6 needs big endian here */
-		__be64 extended_addr;
-		__be16 short_addr;
-	} u;
-};
-
 struct lowpan_addr_info {
-	struct lowpan_addr daddr;
-	struct lowpan_addr saddr;
+	struct ieee802154_addr daddr;
+	struct ieee802154_addr saddr;
 };
 
 static inline struct
@@ -48,12 +39,14 @@ lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb)
  * RAW/DGRAM sockets.
  */
 int lowpan_header_create(struct sk_buff *skb, struct net_device *ldev,
-			 unsigned short type, const void *_daddr,
-			 const void *_saddr, unsigned int len)
+			 unsigned short type, const void *daddr,
+			 const void *saddr, unsigned int len)
 {
-	const u8 *saddr = _saddr;
-	const u8 *daddr = _daddr;
-	struct lowpan_addr_info *info;
+	struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr;
+	struct lowpan_addr_info *info = lowpan_skb_priv(skb);
+	struct lowpan_802154_neigh *llneigh = NULL;
+	const struct ipv6hdr *hdr = ipv6_hdr(skb);
+	struct neighbour *n;
 
 	/* TODO:
 	 * if this package isn't ipv6 one, where should it be routed?
@@ -61,21 +54,50 @@ int lowpan_header_create(struct sk_buff *skb, struct net_device *ldev,
 	if (type != ETH_P_IPV6)
 		return 0;
 
-	if (!saddr)
-		saddr = ldev->dev_addr;
+	/* intra-pan communication */
+	info->saddr.pan_id = wpan_dev->pan_id;
+	info->daddr.pan_id = info->saddr.pan_id;
 
-	raw_dump_inline(__func__, "saddr", (unsigned char *)saddr, 8);
-	raw_dump_inline(__func__, "daddr", (unsigned char *)daddr, 8);
+	if (!memcmp(daddr, ldev->broadcast, EUI64_ADDR_LEN)) {
+		info->daddr.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
+		info->daddr.mode = IEEE802154_ADDR_SHORT;
+	} else {
+		__le16 short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC);
+
+		n = neigh_lookup(&nd_tbl, &hdr->daddr, ldev);
+		if (n) {
+			llneigh = lowpan_802154_neigh(neighbour_priv(n));
+			read_lock_bh(&n->lock);
+			short_addr = llneigh->short_addr;
+			read_unlock_bh(&n->lock);
+		}
 
-	info = lowpan_skb_priv(skb);
+		if (llneigh &&
+		    lowpan_802154_is_valid_src_short_addr(short_addr)) {
+			info->daddr.short_addr = short_addr;
+			info->daddr.mode = IEEE802154_ADDR_SHORT;
+		} else {
+			info->daddr.mode = IEEE802154_ADDR_LONG;
+			ieee802154_be64_to_le64(&info->daddr.extended_addr,
+						daddr);
+		}
 
-	/* TODO: Currently we only support extended_addr */
-	info->daddr.mode = IEEE802154_ADDR_LONG;
-	memcpy(&info->daddr.u.extended_addr, daddr,
-	       sizeof(info->daddr.u.extended_addr));
-	info->saddr.mode = IEEE802154_ADDR_LONG;
-	memcpy(&info->saddr.u.extended_addr, saddr,
-	       sizeof(info->daddr.u.extended_addr));
+		if (n)
+			neigh_release(n);
+	}
+
+	if (!saddr) {
+		if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr)) {
+			info->saddr.mode = IEEE802154_ADDR_SHORT;
+			info->saddr.short_addr = wpan_dev->short_addr;
+		} else {
+			info->saddr.mode = IEEE802154_ADDR_LONG;
+			info->saddr.extended_addr = wpan_dev->extended_addr;
+		}
+	} else {
+		info->saddr.mode = IEEE802154_ADDR_LONG;
+		ieee802154_be64_to_le64(&info->saddr.extended_addr, saddr);
+	}
 
 	return 0;
 }
@@ -209,47 +231,26 @@ static int lowpan_header(struct sk_buff *skb, struct net_device *ldev,
 			 u16 *dgram_size, u16 *dgram_offset)
 {
 	struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr;
-	struct ieee802154_addr sa, da;
 	struct ieee802154_mac_cb *cb = mac_cb_init(skb);
 	struct lowpan_addr_info info;
-	void *daddr, *saddr;
 
 	memcpy(&info, lowpan_skb_priv(skb), sizeof(info));
 
-	/* TODO: Currently we only support extended_addr */
-	daddr = &info.daddr.u.extended_addr;
-	saddr = &info.saddr.u.extended_addr;
-
 	*dgram_size = skb->len;
-	lowpan_header_compress(skb, ldev, daddr, saddr);
+	lowpan_header_compress(skb, ldev, &info.daddr, &info.saddr);
 	/* dgram_offset = (saved bytes after compression) + lowpan header len */
 	*dgram_offset = (*dgram_size - skb->len) + skb_network_header_len(skb);
 
 	cb->type = IEEE802154_FC_TYPE_DATA;
 
-	/* prepare wpan address data */
-	sa.mode = IEEE802154_ADDR_LONG;
-	sa.pan_id = wpan_dev->pan_id;
-	sa.extended_addr = ieee802154_devaddr_from_raw(saddr);
-
-	/* intra-PAN communications */
-	da.pan_id = sa.pan_id;
-
-	/* if the destination address is the broadcast address, use the
-	 * corresponding short address
-	 */
-	if (!memcmp(daddr, ldev->broadcast, EUI64_ADDR_LEN)) {
-		da.mode = IEEE802154_ADDR_SHORT;
-		da.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST);
+	if (info.daddr.mode == IEEE802154_ADDR_SHORT &&
+	    ieee802154_is_broadcast_short_addr(info.daddr.short_addr))
 		cb->ackreq = false;
-	} else {
-		da.mode = IEEE802154_ADDR_LONG;
-		da.extended_addr = ieee802154_devaddr_from_raw(daddr);
+	else
 		cb->ackreq = wpan_dev->ackreq;
-	}
 
-	return wpan_dev_hard_header(skb, lowpan_802154_dev(ldev)->wdev, &da,
-				    &sa, 0);
+	return wpan_dev_hard_header(skb, lowpan_802154_dev(ldev)->wdev,
+				    &info.daddr, &info.saddr, 0);
 }
 
 netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev)