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authorTony Cheneau <tony.cheneau@amnesiak.org>2013-03-25 17:59:32 +0000
committerDavid S. Miller <davem@davemloft.net>2013-03-26 12:37:58 -0400
commit24363b67328733ad11ceadffe72a9721a37a3e9e (patch)
tree2e85baf2b2ad779991166a7a664f7f3ee065887b /net/ieee802154/6lowpan.c
parent43de7aa6ac4e37eaf0a5e83adc0a79d61fe3a55a (diff)
6lowpan: modify udp compression/uncompression to match the standard
The previous code would just compress the UDP header and send the compressed UDP header along with the uncompressed one. Signed-off-by: Tony Cheneau <tony.cheneau@amnesiak.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ieee802154/6lowpan.c')
-rw-r--r--net/ieee802154/6lowpan.c39
1 files changed, 36 insertions, 3 deletions
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 276971ba3ade..c9c3f3d18c41 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -284,6 +284,9 @@ lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
/* checksum is always inline */
memcpy(*hc06_ptr, &uh->check, 2);
*hc06_ptr += 2;
+
+ /* skip the UDP header */
+ skb_pull(skb, sizeof(struct udphdr));
}
static inline int lowpan_fetch_skb_u8(struct sk_buff *skb, u8 *val)
@@ -309,9 +312,8 @@ static inline int lowpan_fetch_skb_u16(struct sk_buff *skb, u16 *val)
}
static int
-lowpan_uncompress_udp_header(struct sk_buff *skb)
+lowpan_uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh)
{
- struct udphdr *uh = udp_hdr(skb);
u8 tmp;
if (!uh)
@@ -358,6 +360,14 @@ lowpan_uncompress_udp_header(struct sk_buff *skb)
/* copy checksum */
memcpy(&uh->check, &skb->data[0], 2);
skb_pull(skb, 2);
+
+ /*
+ * UDP lenght needs to be infered from the lower layers
+ * here, we obtain the hint from the remaining size of the
+ * frame
+ */
+ uh->len = htons(skb->len + sizeof(struct udphdr));
+ pr_debug("uncompressed UDP length: src = %d", uh->len);
} else {
pr_debug("ERROR: unsupported NH format\n");
goto err;
@@ -944,8 +954,31 @@ lowpan_process_data(struct sk_buff *skb)
/* UDP data uncompression */
if (iphc0 & LOWPAN_IPHC_NH_C) {
- if (lowpan_uncompress_udp_header(skb))
+ struct udphdr uh;
+ struct sk_buff *new;
+ if (lowpan_uncompress_udp_header(skb, &uh))
goto drop;
+
+ /*
+ * replace the compressed UDP head by the uncompressed UDP
+ * header
+ */
+ new = skb_copy_expand(skb, sizeof(struct udphdr),
+ skb_tailroom(skb), GFP_ATOMIC);
+ kfree_skb(skb);
+
+ if (!new)
+ return -ENOMEM;
+
+ skb = new;
+
+ skb_push(skb, sizeof(struct udphdr));
+ skb_reset_transport_header(skb);
+ skb_copy_to_linear_data(skb, &uh, sizeof(struct udphdr));
+
+ lowpan_raw_dump_table(__func__, "raw UDP header dump",
+ (u8 *)&uh, sizeof(uh));
+
hdr.nexthdr = UIP_PROTO_UDP;
}