From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: [PATCH net] ipv6: drop packets with multiple fragmentation headers Date: Fri, 16 Aug 2013 13:30:07 +0200 Message-ID: <20130816113007.GD2112@order.stressinduktion.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: yoshfuji@linux-ipv6.org To: netdev@vger.kernel.org Return-path: Received: from order.stressinduktion.org ([87.106.68.36]:55690 "EHLO order.stressinduktion.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753068Ab3HPLaI (ORCPT ); Fri, 16 Aug 2013 07:30:08 -0400 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: It is not allowed for an ipv6 packet to contain multiple fragmentation headers. So discard packets which were already reassembled by fragmentation logic and send back a parameter problem icmp. The updates for RFC 6980 will come in later, I have to do a bit more research here. Cc: YOSHIFUJI Hideaki Signed-off-by: Hannes Frederic Sowa --- include/linux/ipv6.h | 1 + net/ipv6/reassembly.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 77a4784..9ac5047 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -103,6 +103,7 @@ struct inet6_skb_parm { #define IP6SKB_FORWARDED 2 #define IP6SKB_REROUTED 4 #define IP6SKB_ROUTERALERT 8 +#define IP6SKB_FRAGMENTED 16 }; #define IP6CB(skb) ((struct inet6_skb_parm*)((skb)->cb)) diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 790d9f4..1aeb473 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -490,6 +490,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, ipv6_hdr(head)->payload_len = htons(payload_len); ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); IP6CB(head)->nhoff = nhoff; + IP6CB(head)->flags |= IP6SKB_FRAGMENTED; /* Yes, and fold redundant checksum back. 8) */ if (head->ip_summed == CHECKSUM_COMPLETE) @@ -524,6 +525,9 @@ static int ipv6_frag_rcv(struct sk_buff *skb) struct net *net = dev_net(skb_dst(skb)->dev); int evicted; + if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) + goto fail_hdr; + IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); /* Jumbo payload inhibits frag. header */ @@ -544,6 +548,7 @@ static int ipv6_frag_rcv(struct sk_buff *skb) ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); + IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; return 1; } -- 1.8.3.1