From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com ([134.134.136.20]:10310 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966265AbcCPNj5 (ORCPT ); Wed, 16 Mar 2016 09:39:57 -0400 Message-ID: <1458135593.5711.28.camel@linux.intel.com> Subject: Re: [PATCH bluetooth-next] 6lowpan: iphc: fix handling of link-local compression From: Jukka Rissanen Date: Wed, 16 Mar 2016 15:39:53 +0200 In-Reply-To: <1458132761-24055-1-git-send-email-aar@pengutronix.de> References: <1458132761-24055-1-git-send-email-aar@pengutronix.de> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit 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 Hi Alex, On Wed, 2016-03-16 at 13:52 +0100, 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. Makes sense although this is probably very unlikely thing to happen. Acked-by: Jukka Rissanen > 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, >    &hd > r->saddr, >    sad > dr, 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, >    &hd > r->daddr, >    dad > dr, false); Cheers, Jukka