6lowpan: udp use lowpan_push_hc_data function

This patch uses the lowpan_push_hc_data to generate iphc header.

The current implementation has some wrong pointer arithmetic issues and
works in a random case only.

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

1 files changed, 20 insertions, 17 deletions

diff --git a/net/ieee802154/6lowpan_iphc.c b/net/ieee802154/6lowpan_iphc.c
index 88e7da599558..77c0366a3b47 100644
--- a/net/ieee802154/6lowpan_iphc.c
+++ b/net/ieee802154/6lowpan_iphc.c
@@ -541,42 +541,45 @@ static u8 lowpan_compress_addr_64(u8 **hc06_ptr, u8 shift,
 static void compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
 {
         struct udphdr *uh = udp_hdr(skb);
+        u8 tmp;
 
         if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) ==
                                 LOWPAN_NHC_UDP_4BIT_PORT) &&
             ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) ==
                                 LOWPAN_NHC_UDP_4BIT_PORT)) {
                 pr_debug("UDP header: both ports compression to 4 bits\n");
-                **hc06_ptr = LOWPAN_NHC_UDP_CS_P_11;
-                **(hc06_ptr + 1) = /* subtraction is faster */
+                tmp = LOWPAN_NHC_UDP_CS_P_11;
+                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
+                tmp = /* subtraction is faster */
                    (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) +
                        ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4));
-                *hc06_ptr += 2;
+                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
         } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) ==
                         LOWPAN_NHC_UDP_8BIT_PORT) {
                 pr_debug("UDP header: remove 8 bits of dest\n");
-                **hc06_ptr = LOWPAN_NHC_UDP_CS_P_01;
-                memcpy(*hc06_ptr + 1, &uh->source, 2);
-                **(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT);
-                *hc06_ptr += 4;
+                tmp = LOWPAN_NHC_UDP_CS_P_01;
+                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
+                lowpan_push_hc_data(hc06_ptr, &uh->source, sizeof(uh->source));
+                tmp = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT);
+                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
         } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) ==
                         LOWPAN_NHC_UDP_8BIT_PORT) {
                 pr_debug("UDP header: remove 8 bits of source\n");
-                **hc06_ptr = LOWPAN_NHC_UDP_CS_P_10;
-                memcpy(*hc06_ptr + 1, &uh->dest, 2);
-                **(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT);
-                *hc06_ptr += 4;
+                tmp = LOWPAN_NHC_UDP_CS_P_10;
+                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
+                lowpan_push_hc_data(hc06_ptr, &uh->dest, sizeof(uh->dest));
+                tmp = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT);
+                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
         } else {
                 pr_debug("UDP header: can't compress\n");
-                **hc06_ptr = LOWPAN_NHC_UDP_CS_P_00;
-                memcpy(*hc06_ptr + 1, &uh->source, 2);
-                memcpy(*hc06_ptr + 3, &uh->dest, 2);
-                *hc06_ptr += 5;
+                tmp = LOWPAN_NHC_UDP_CS_P_00;
+                lowpan_push_hc_data(hc06_ptr, &tmp, sizeof(tmp));
+                lowpan_push_hc_data(hc06_ptr, &uh->source, sizeof(uh->source));
+                lowpan_push_hc_data(hc06_ptr, &uh->dest, sizeof(uh->dest));
         }
 
         /* checksum is always inline */
-        memcpy(*hc06_ptr, &uh->check, 2);
-        *hc06_ptr += 2;
+        lowpan_push_hc_data(hc06_ptr, &uh->check, sizeof(uh->check));
 
         /* skip the UDP header */
         skb_pull(skb, sizeof(struct udphdr));