| Date | Mon, 12 May 2014 02:33:09 +0200 | From | Willy Tarreau <> | Subject | [ 069/143] ipv6: drop packets with multiple fragmentation headers |
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2.6.32-longterm review patch. If anyone has any objections, please let me know.
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From: Hannes Frederic Sowa <hannes@stressinduktion.org>
[ Upstream commit f46078cfcd77fa5165bf849f5e568a7ac5fa569c ]
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 <yoshfuji@linux-ipv6.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Willy Tarreau <w@1wt.eu> --- 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 c662efa..5bf3324 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -248,6 +248,7 @@ struct inet6_skb_parm { #define IP6SKB_XFRM_TRANSFORMED 1 #define IP6SKB_FORWARDED 2 +#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 105de22..0c09d8e 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -503,6 +503,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, head->tstamp = fq->q.stamp; ipv6_hdr(head)->payload_len = htons(payload_len); IP6CB(head)->nhoff = nhoff; + IP6CB(head)->flags |= IP6SKB_FRAGMENTED; /* Yes, and fold redundant checksum back. 8) */ if (head->ip_summed == CHECKSUM_COMPLETE) @@ -537,6 +538,9 @@ static int ipv6_frag_rcv(struct sk_buff *skb) struct ipv6hdr *hdr = ipv6_hdr(skb); struct net *net = dev_net(skb_dst(skb)->dev); + 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 */ @@ -557,6 +561,7 @@ 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; } -- 1.7.12.2.21.g234cd45.dirty
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