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authorAlexander Aring <alex.aring@gmail.com>2013-12-17 17:21:25 +0400
committerMarcel Holtmann <marcel@holtmann.org>2013-12-17 18:16:48 +0400
commit573701ce3715434f01a8baea3255da8d04ad5979 (patch)
tree65925d37c0b3a48f0918e66716db81f364549834
parente5d966eff3ac364e4505c7c4da632321657029b3 (diff)
downloadlinux-573701ce3715434f01a8baea3255da8d04ad5979.tar.xz
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: Alexander Aring <alex.aring@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
-rw-r--r--net/ieee802154/6lowpan.h1
-rw-r--r--net/ieee802154/6lowpan_iphc.c11
2 files changed, 9 insertions, 3 deletions
diff --git a/net/ieee802154/6lowpan.h b/net/ieee802154/6lowpan.h
index 4981bf859e5b..2b835db3bda8 100644
--- a/net/ieee802154/6lowpan.h
+++ b/net/ieee802154/6lowpan.h
@@ -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 */
diff --git a/net/ieee802154/6lowpan_iphc.c b/net/ieee802154/6lowpan_iphc.c
index 02bf74d80e72..a70fa66b5357 100644
--- a/net/ieee802154/6lowpan_iphc.c
+++ b/net/ieee802154/6lowpan_iphc.c
@@ -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 */
- memcpy(&uh->check, &skb->data[0], 2);
- skb_pull(skb, 2);
+ /* 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