6lowpan: iphc: fix handling of link-local compression
This patch fixes handling in case of link-local address compression. A
IPv6 link-local address is defined as fe80::/10 prefix which is also
what ipv6_addr_type checks for link-local addresses.
But IPHC compression for link-local addresses are for fe80::/64 types
only. This patch adds additional checks for zero padded bits in case of
link-local address compression to match on a fe80::/64 address only.
Signed-off-by: Alexander Aring <aar@pengutronix.de>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c
index 99bb22a..68c80f3 100644
--- a/net/6lowpan/iphc.c
+++ b/net/6lowpan/iphc.c
@@ -148,6 +148,11 @@
(((a)->s6_addr16[6]) == 0) && \
(((a)->s6_addr[14]) == 0))
+#define lowpan_is_linklocal_zero_padded(a) \
+ (!(hdr->saddr.s6_addr[1] & 0x3f) && \
+ !hdr->saddr.s6_addr16[1] && \
+ !hdr->saddr.s6_addr32[1])
+
#define LOWPAN_IPHC_CID_DCI(cid) (cid & 0x0f)
#define LOWPAN_IPHC_CID_SCI(cid) ((cid & 0xf0) >> 4)
@@ -1101,7 +1106,8 @@
true);
iphc1 |= LOWPAN_IPHC_SAC;
} else {
- if (ipv6_saddr_type & IPV6_ADDR_LINKLOCAL) {
+ if (ipv6_saddr_type & IPV6_ADDR_LINKLOCAL &&
+ lowpan_is_linklocal_zero_padded(hdr->saddr)) {
iphc1 |= lowpan_compress_addr_64(&hc_ptr,
&hdr->saddr,
saddr, true);
@@ -1135,7 +1141,8 @@
false);
iphc1 |= LOWPAN_IPHC_DAC;
} else {
- if (ipv6_daddr_type & IPV6_ADDR_LINKLOCAL) {
+ if (ipv6_daddr_type & IPV6_ADDR_LINKLOCAL &&
+ lowpan_is_linklocal_zero_padded(hdr->daddr)) {
iphc1 |= lowpan_compress_addr_64(&hc_ptr,
&hdr->daddr,
daddr, false);