6lowpan: cleanup udp compress function

This patch remove unnecessary casts and brackets in compress_udp_header
function.

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

diff --git a/net/ieee802154/6lowpan_iphc.c b/net/ieee802154/6lowpan_iphc.c
index b298bfc..11840f9 100644 (file)
--- a/net/ieee802154/6lowpan_iphc.c
+++ b/net/ieee802154/6lowpan_iphc.c
@@ -553,33 +553,43 @@ static void compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
            ((ntohs(uh->dest) & LOWPAN_NHC_UDP_4BIT_MASK) ==
             LOWPAN_NHC_UDP_4BIT_PORT)) {
                pr_debug("UDP header: both ports compression to 4 bits\n");
+               /* compression value */
                tmp = LOWPAN_NHC_UDP_CS_P_11;
                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
-               tmp = /* subtraction is faster */
-                  (u8)((ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT) +
-                      ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4));
+               /* source and destination port */
+               tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_4BIT_PORT +
+                     ((ntohs(uh->source) - LOWPAN_NHC_UDP_4BIT_PORT) << 4);
                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
        } else if ((ntohs(uh->dest) & LOWPAN_NHC_UDP_8BIT_MASK) ==
                        LOWPAN_NHC_UDP_8BIT_PORT) {
                pr_debug("UDP header: remove 8 bits of dest\n");
+               /* compression value */
                tmp = LOWPAN_NHC_UDP_CS_P_01;
                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
+               /* source port */
                lowpan_push_hc_data(hc06_ptr, &uh->source, sizeof(uh->source));
-               tmp = (u8)(ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT);
+               /* destination port */
+               tmp = ntohs(uh->dest) - LOWPAN_NHC_UDP_8BIT_PORT;
                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
        } else if ((ntohs(uh->source) & LOWPAN_NHC_UDP_8BIT_MASK) ==
                        LOWPAN_NHC_UDP_8BIT_PORT) {
                pr_debug("UDP header: remove 8 bits of source\n");
+               /* compression value */
                tmp = LOWPAN_NHC_UDP_CS_P_10;
                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
-               tmp = (u8)(ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT);
+               /* source port */
+               tmp = ntohs(uh->source) - LOWPAN_NHC_UDP_8BIT_PORT;
                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
+               /* destination port */
                lowpan_push_hc_data(hc06_ptr, &uh->dest, sizeof(uh->dest));
        } else {
                pr_debug("UDP header: can't compress\n");
+               /* compression value */
                tmp = LOWPAN_NHC_UDP_CS_P_00;
                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
+               /* source port */
                lowpan_push_hc_data(hc06_ptr, &uh->source, sizeof(uh->source));
+               /* destination port */
                lowpan_push_hc_data(hc06_ptr, &uh->dest, sizeof(uh->dest));
        }