From feb2add3235ca81dc5cd5d975490c707a24c9889 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Wed, 16 Mar 2016 13:52:41 +0100 Subject: [PATCH] 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 Acked-by: Jukka Rissanen Reviewed-by: Stefan Schmidt Signed-off-by: Marcel Holtmann --- net/6lowpan/iphc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c index 99bb22aea346..68c80f3c9add 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 @@ int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev, 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 @@ int lowpan_header_compress(struct sk_buff *skb, const struct net_device *dev, 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); -- 2.20.1