From: Shan Wei Date: Sun, 18 Apr 2010 16:58:22 +0000 (+0000) Subject: ipv6: allow to send packet after receiving ICMPv6 Too Big message with MTU field... X-Git-Tag: v2.6.34-rc6~33^2~6 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f2228f785a9d97307aa8ba709088cfda6c3df73f;p=pandora-kernel.git ipv6: allow to send packet after receiving ICMPv6 Too Big message with MTU field less than IPV6_MIN_MTU According to RFC2460, PMTU is set to the IPv6 Minimum Link MTU (1280) and a fragment header should always be included after a node receiving Too Big message reporting PMTU is less than the IPv6 Minimum Link MTU. After receiving a ICMPv6 Too Big message reporting PMTU is less than the IPv6 Minimum Link MTU, sctp *can't* send any data/control chunk that total length including IPv6 head and IPv6 extend head is less than IPV6_MIN_MTU(1280 bytes). The failure occured in p6_fragment(), about reason see following(take SHUTDOWN chunk for example): sctp_packet_transmit (SHUTDOWN chunk, len=16 byte) |------sctp_v6_xmit (local_df=0) |------ip6_xmit |------ip6_output (dst_allfrag is ture) |------ip6_fragment In ip6_fragment(), for local_df=0, drops the the packet and returns EMSGSIZE. The patch fixes it with adding check length of skb->len. In this case, Ipv6 not to fragment upper protocol data, just only add a fragment header before it. Signed-off-by: Shan Wei Signed-off-by: David S. Miller --- Reading git-diff-tree failed