[Linux-zigbee-devel] [PATCH 5/6] [6LoWPAN] UDP header decompression

[Alexander Smirnov]

This patch provides possibility to decompress UDP headers.
Derived from Contiki OS.

Signed-off-by: Alexander Smirnov <alex.bluesman.smir...@gmail.com>
---
 net/ieee802154/6lowpan.c |   50 +++++++++++++++++++++++++++++++++++++++++++++-
 1 files changed, 49 insertions(+), 1 deletions(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 6da3357..49f42a8 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -839,7 +839,55 @@ lowpan_process_data(struct sk_buff *skb)
                        goto drop;
        }
 
-       /* TODO: UDP header parse */
+       /* UDP data uncompression */
+       if (iphc0 & LOWPAN_IPHC_NH_C) {
+               tmp = lowpan_fetch_skb_u8(skb);
+
+               if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
+                       struct udphdr *uh = udp_hdr(skb);
+
+                       pr_debug("(%s): UDP header uncompression\n", __func__);
+                       switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
+                       case LOWPAN_NHC_UDP_CS_P_00:
+                               memcpy(&uh->source, &skb->data[0], 2);
+                               memcpy(&uh->dest, &skb->data[2], 2);
+                               skb_pull(skb, 4);
+                               break;
+                       case LOWPAN_NHC_UDP_CS_P_01:
+                               memcpy(&uh->source, &skb->data[0], 2);
+                               uh->dest =
+                                  skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
+                               skb_pull(skb, 3);
+                               break;
+                       case LOWPAN_NHC_UDP_CS_P_10:
+                               uh->source = skb->data[0] + 
LOWPAN_NHC_UDP_8BIT_PORT;
+                               memcpy(&uh->dest, &skb->data[1], 2);
+                               skb_pull(skb, 3);
+                               break;
+                       case LOWPAN_NHC_UDP_CS_P_11:
+                               uh->source =
+                                  LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 
4);
+                               uh->dest =
+                                  LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 
0x0f);
+                               skb_pull(skb, 1);
+                               break;
+                       default:
+                               pr_debug("(%s) ERROR: unknown UDP format\n", 
__func__);
+                               goto drop;
+                       }
+
+                       pr_debug("(%s): uncompressed UDP ports: src = %d, dst = 
%d\n",
+                                       __func__, uh->source, uh->dest);
+
+                       /* copy checksum */
+                       memcpy(&uh->check, &skb->data[0], 2);
+                       skb_pull(skb, 2);
+               } else {
+                       pr_debug("(%s): ERROR: unsupported NH format\n",
+                                                               __func__);
+                       goto drop;
+               }
+       }
 
        /* Not fragmented package */
        hdr.payload_len = htons(skb->len);
-- 
1.7.2.5


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