Commit 24363b67 authored by Tony Cheneau's avatar Tony Cheneau Committed by David S. Miller
Browse files

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: default avatarTony Cheneau <tony.cheneau@amnesiak.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 43de7aa6

net/ieee802154/6lowpan.c

+36 −3
Original line number Diff line number Diff line
@@ -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;

	}