Re: [PATCH bluetooth-next] 6lowpan: iphc: fix handling of link-local compression

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello.

On 16/03/16 13:52, Alexander Aring wrote:
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@xxxxxxxxxxxxxx>
---
  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 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 @@ 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);

Nicely spotted.

Reviewed-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxx>

regards
Stefan Schmidt
--
To unsubscribe from this list: send the line "unsubscribe linux-wpan" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux NFS]     [Linux NILFS]     [Linux USB Devel]     [Linux Audio Users]     [Photo]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux