From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.s-osg.org ([54.187.51.154]:54194 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751971AbcCPPoT (ORCPT ); Wed, 16 Mar 2016 11:44:19 -0400 Subject: Re: [PATCH bluetooth-next] 6lowpan: iphc: fix handling of link-local compression References: <1458132761-24055-1-git-send-email-aar@pengutronix.de> From: Stefan Schmidt Message-ID: <56E97F4E.2020201@osg.samsung.com> Date: Wed, 16 Mar 2016 16:44:14 +0100 MIME-Version: 1.0 In-Reply-To: <1458132761-24055-1-git-send-email-aar@pengutronix.de> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-wpan-owner@vger.kernel.org List-ID: To: Alexander Aring , linux-wpan@vger.kernel.org Cc: linux-bluetooth@vger.kernel.org, kernel@pengutronix.de, jukka.rissanen@linux.intel.com 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 > --- > 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 regards Stefan Schmidt