6lowpan: Use netdev addr_len to determine lladdr len

This allow technologies such as Bluetooth to use its native lladdr which
is eui48 instead of eui64 which was expected by functions like
lowpan_header_decompress and lowpan_header_compress.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

3 files changed, 63 insertions, 47 deletions

diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
index 5ab4c9901ccc..c5792cb6c3eb 100644
--- a/include/net/6lowpan.h
+++ b/include/net/6lowpan.h
@@ -198,6 +198,25 @@ static inline void lowpan_iphc_uncompress_eui64_lladdr(struct in6_addr *ipaddr,
         ipaddr->s6_addr[8] ^= 0x02;
 }
 
+static inline void lowpan_iphc_uncompress_eui48_lladdr(struct in6_addr *ipaddr,
+                                                       const void *lladdr)
+{
+        /* fe:80::XXXX:XXff:feXX:XXXX
+         *        \_________________/
+         *              hwaddr
+         */
+        ipaddr->s6_addr[0] = 0xFE;
+        ipaddr->s6_addr[1] = 0x80;
+        memcpy(&ipaddr->s6_addr[8], lladdr, 3);
+        ipaddr->s6_addr[11] = 0xFF;
+        ipaddr->s6_addr[12] = 0xFE;
+        memcpy(&ipaddr->s6_addr[13], lladdr + 3, 3);
+        /* second bit-flip (Universe/Local)
+         * is done according RFC2464
+         */
+        ipaddr->s6_addr[8] ^= 0x02;
+}
+
 #ifdef DEBUG
 /* print data in line */
 static inline void raw_dump_inline(const char *caller, char *msg,
diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c
index fb5f6fa8f1df..6b1042e21656 100644
--- a/net/6lowpan/iphc.c
+++ b/net/6lowpan/iphc.c
@@ -278,6 +278,23 @@ lowpan_iphc_ctx_get_by_mcast_addr(const struct net_device *dev,
         return ret;
 }
 
+static void lowpan_iphc_uncompress_lladdr(const struct net_device *dev,
+                                          struct in6_addr *ipaddr,
+                                          const void *lladdr)
+{
+        switch (dev->addr_len) {
+        case ETH_ALEN:
+                lowpan_iphc_uncompress_eui48_lladdr(ipaddr, lladdr);
+                break;
+        case EUI64_ADDR_LEN:
+                lowpan_iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
+                break;
+        default:
+                WARN_ON_ONCE(1);
+                break;
+        }
+}
+
 /* Uncompress address function for source and
  * destination address(non-multicast).
  *
@@ -320,7 +337,7 @@ static int lowpan_iphc_uncompress_addr(struct sk_buff *skb,
                         lowpan_iphc_uncompress_802154_lladdr(ipaddr, lladdr);
                         break;
                 default:
-                        lowpan_iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
+                        lowpan_iphc_uncompress_lladdr(dev, ipaddr, lladdr);
                         break;
                 }
                 break;
@@ -381,7 +398,7 @@ static int lowpan_iphc_uncompress_ctx_addr(struct sk_buff *skb,
                         lowpan_iphc_uncompress_802154_lladdr(ipaddr, lladdr);
                         break;
                 default:
-                        lowpan_iphc_uncompress_eui64_lladdr(ipaddr, lladdr);
+                        lowpan_iphc_uncompress_lladdr(dev, ipaddr, lladdr);
                         break;
                 }
                 ipv6_addr_prefix_copy(ipaddr, &ctx->pfx, ctx->plen);
@@ -810,6 +827,21 @@ lowpan_iphc_compress_ctx_802154_lladdr(const struct in6_addr *ipaddr,
         return lladdr_compress;
 }
 
+static bool lowpan_iphc_addr_equal(const struct net_device *dev,
+                                   const struct lowpan_iphc_ctx *ctx,
+                                   const struct in6_addr *ipaddr,
+                                   const void *lladdr)
+{
+        struct in6_addr tmp = {};
+
+        lowpan_iphc_uncompress_lladdr(dev, &tmp, lladdr);
+
+        if (ctx)
+                ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
+
+        return ipv6_addr_equal(&tmp, ipaddr);
+}
+
 static u8 lowpan_compress_ctx_addr(u8 **hc_ptr, const struct net_device *dev,
                                    const struct in6_addr *ipaddr,
                                    const struct lowpan_iphc_ctx *ctx,
@@ -827,13 +859,7 @@ static u8 lowpan_compress_ctx_addr(u8 **hc_ptr, const struct net_device *dev,
                 }
                 break;
         default:
-                /* check for SAM/DAM = 11 */
-                memcpy(&tmp.s6_addr[8], lladdr, EUI64_ADDR_LEN);
-                /* second bit-flip (Universe/Local) is done according RFC2464 */
-                tmp.s6_addr[8] ^= 0x02;
-                /* context information are always used */
-                ipv6_addr_prefix_copy(&tmp, &ctx->pfx, ctx->plen);
-                if (ipv6_addr_equal(&tmp, ipaddr)) {
+                if (lowpan_iphc_addr_equal(dev, ctx, ipaddr, lladdr)) {
                         dam = LOWPAN_IPHC_DAM_11;
                         goto out;
                 }
@@ -929,11 +955,12 @@ static u8 lowpan_compress_addr_64(u8 **hc_ptr, const struct net_device *dev,
                 }
                 break;
         default:
-                if (is_addr_mac_addr_based(ipaddr, lladdr)) {
-                        dam = LOWPAN_IPHC_DAM_11; /* 0-bits */
+                if (lowpan_iphc_addr_equal(dev, NULL, ipaddr, lladdr)) {
+                        dam = LOWPAN_IPHC_DAM_11;
                         pr_debug("address compression 0 bits\n");
                         goto out;
                 }
+
                 break;
         }
 
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index bad0e9d1ea20..54bf4d765a7d 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -64,7 +64,7 @@ struct lowpan_peer {
         struct l2cap_chan *chan;
 
         /* peer addresses in various formats */
-        unsigned char eui64_addr[EUI64_ADDR_LEN];
+        unsigned char lladdr[ETH_ALEN];
         struct in6_addr peer_addr;
 };
 
@@ -80,8 +80,6 @@ struct lowpan_btle_dev {
         struct delayed_work notify_peers;
 };
 
-static void set_addr(u8 *eui, u8 *addr, u8 addr_type);
-
 static inline struct lowpan_btle_dev *
 lowpan_btle_dev(const struct net_device *netdev)
 {
@@ -277,7 +275,6 @@ static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
         const u8 *saddr;
         struct lowpan_btle_dev *dev;
         struct lowpan_peer *peer;
-        unsigned char eui64_daddr[EUI64_ADDR_LEN];
 
         dev = lowpan_btle_dev(netdev);
 
@@ -287,10 +284,9 @@ static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
         if (!peer)
                 return -EINVAL;
 
-        saddr = peer->eui64_addr;
-        set_addr(&eui64_daddr[0], chan->src.b, chan->src_type);
+        saddr = peer->lladdr;
 
-        return lowpan_header_decompress(skb, netdev, &eui64_daddr, saddr);
+        return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
 }
 
 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
@@ -477,7 +473,7 @@ static int setup_header(struct sk_buff *skb, struct net_device *netdev,
                         }
                 }
 
-                daddr = peer->eui64_addr;
+                daddr = peer->lladdr;
                 *peer_addr = addr;
                 *peer_addr_type = addr_type;
                 lowpan_cb(skb)->chan = peer->chan;
@@ -663,27 +659,6 @@ static struct device_type bt_type = {
         .name   = "bluetooth",
 };
 
-static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
-{
-        /* addr is the BT address in little-endian format */
-        eui[0] = addr[5];
-        eui[1] = addr[4];
-        eui[2] = addr[3];
-        eui[3] = 0xFF;
-        eui[4] = 0xFE;
-        eui[5] = addr[2];
-        eui[6] = addr[1];
-        eui[7] = addr[0];
-
-        /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
-        if (addr_type == BDADDR_LE_PUBLIC)
-                eui[0] &= ~0x02;
-        else
-                eui[0] |= 0x02;
-
-        BT_DBG("type %d addr %*phC", addr_type, 8, eui);
-}
-
 static void ifup(struct net_device *netdev)
 {
         int err;
@@ -762,14 +737,9 @@ static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
         peer->chan = chan;
         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 
-        /* RFC 2464 ch. 5 */
-        peer->peer_addr.s6_addr[0] = 0xFE;
-        peer->peer_addr.s6_addr[1] = 0x80;
-        set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
-                 chan->dst_type);
+        baswap((void *)peer->lladdr, &chan->dst);
 
-        memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
-               EUI64_ADDR_LEN);
+        lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
 
         /* IPv6 address needs to have the U/L bit set properly so toggle
          * it back here.