Commit 573701ce authored by Alexander Aring's avatar Alexander Aring Committed by Marcel Holtmann
Browse files

6lowpan: add udp warning for elided checksum 

Bit 5 of "UDP LOWPAN_NHC Format" indicate that the checksum can be
elided.
The host need to calculate the udp checksum afterwards but this isn't
supported right now.

See:
http://tools.ietf.org/html/rfc6282#section-4.3.3


Signed-off-by: default avatarAlexander Aring <alex.aring@gmail.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent e5d966ef

net/ieee802154/6lowpan.h

+1 −0
Original line number Diff line number Diff line
@@ -231,6 +231,7 @@ 
#define LOWPAN_NHC_UDP_CS_P_10	0xF2 /* source = 0xF0 + 8bit inline,

					dest = 16 bit inline */

#define LOWPAN_NHC_UDP_CS_P_11	0xF3 /* source & dest = 0xF0B + 4bit inline */

#define LOWPAN_NHC_UDP_CS_C	0x04 /* checksum elided */



#ifdef DEBUG

/* print data in line */

net/ieee802154/6lowpan_iphc.c

+8 −3
Original line number Diff line number Diff line
@@ -309,9 +309,14 @@ uncompress_udp_header(struct sk_buff *skb, struct udphdr *uh) 
		pr_debug("uncompressed UDP ports: src = %d, dst = %d\n",

			 ntohs(uh->source), ntohs(uh->dest));



		/* copy checksum */

		/* checksum */

		if (tmp & LOWPAN_NHC_UDP_CS_C) {

			pr_debug_ratelimited("checksum elided currently not supported\n");

			goto err;

		} else {

			memcpy(&uh->check, &skb->data[0], 2);

			skb_pull(skb, 2);

		}



		/*

		 * UDP lenght needs to be infered from the lower layers

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