6lowpan: put mcast compression in an own function

This patch moves the mcast compression algorithmn to an own function
like all other compression/decompression methods in iphc.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c
index e6cdfc9..346b5c1 100644 (file)
--- a/net/6lowpan/iphc.c
+++ b/net/6lowpan/iphc.c
@@ -708,6 +708,37 @@ static u8 lowpan_iphc_tf_compress(u8 **hc_ptr, const struct ipv6hdr *hdr)
        return val;
 }
 
+static u8 lowpan_iphc_mcast_addr_compress(u8 **hc_ptr,
+                                         const struct in6_addr *ipaddr)
+{
+       u8 val;
+
+       if (lowpan_is_mcast_addr_compressable8(ipaddr)) {
+               pr_debug("compressed to 1 octet\n");
+               /* use last byte */
+               lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[15], 1);
+               val = LOWPAN_IPHC_DAM_11;
+       } else if (lowpan_is_mcast_addr_compressable32(ipaddr)) {
+               pr_debug("compressed to 4 octets\n");
+               /* second byte + the last three */
+               lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
+               lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[13], 3);
+               val = LOWPAN_IPHC_DAM_10;
+       } else if (lowpan_is_mcast_addr_compressable48(ipaddr)) {
+               pr_debug("compressed to 6 octets\n");
+               /* second byte + the last five */
+               lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[1], 1);
+               lowpan_push_hc_data(hc_ptr, &ipaddr->s6_addr[11], 5);
+               val = LOWPAN_IPHC_DAM_01;
+       } else {
+               pr_debug("using full address\n");
+               lowpan_push_hc_data(hc_ptr, ipaddr->s6_addr, 16);
+               val = LOWPAN_IPHC_DAM_00;
+       }
+
+       return val;
+}
+
 int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
                           const void *daddr, const void *saddr)
 {
@@ -804,33 +835,7 @@ int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev,
        if (addr_type & IPV6_ADDR_MULTICAST) {
                pr_debug("destination address is multicast: ");
                iphc1 |= LOWPAN_IPHC_M;
-               if (lowpan_is_mcast_addr_compressable8(&hdr->daddr)) {
-                       pr_debug("compressed to 1 octet\n");
-                       iphc1 |= LOWPAN_IPHC_DAM_11;
-                       /* use last byte */
-                       lowpan_push_hc_data(&hc_ptr,
-                                           &hdr->daddr.s6_addr[15], 1);
-               } else if (lowpan_is_mcast_addr_compressable32(&hdr->daddr)) {
-                       pr_debug("compressed to 4 octets\n");
-                       iphc1 |= LOWPAN_IPHC_DAM_10;
-                       /* second byte + the last three */
-                       lowpan_push_hc_data(&hc_ptr,
-                                           &hdr->daddr.s6_addr[1], 1);
-                       lowpan_push_hc_data(&hc_ptr,
-                                           &hdr->daddr.s6_addr[13], 3);
-               } else if (lowpan_is_mcast_addr_compressable48(&hdr->daddr)) {
-                       pr_debug("compressed to 6 octets\n");
-                       iphc1 |= LOWPAN_IPHC_DAM_01;
-                       /* second byte + the last five */
-                       lowpan_push_hc_data(&hc_ptr,
-                                           &hdr->daddr.s6_addr[1], 1);
-                       lowpan_push_hc_data(&hc_ptr,
-                                           &hdr->daddr.s6_addr[11], 5);
-               } else {
-                       pr_debug("using full address\n");
-                       iphc1 |= LOWPAN_IPHC_DAM_00;
-                       lowpan_push_hc_data(&hc_ptr, hdr->daddr.s6_addr, 16);
-               }
+               iphc1 |= lowpan_iphc_mcast_addr_compress(&hc_ptr, &hdr->daddr);
        } else {
                if (addr_type & IPV6_ADDR_LINKLOCAL) {
                        /* TODO: context lookup */