From dbd1759e6a9c4596d8609897c414da603da80914 Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Wed, 2 Nov 2016 11:02:18 -0400 Subject: [PATCH] ipv6: on reassembly, record frag_max_size IP6CB and IPCB have a frag_max_size field. In IPv6 this field is filled in when packets are reassembled by the connection tracking code. Also fill in when reassembling in the input path, to expose it through cmsg IPV6_RECVFRAGSIZE in all cases. Signed-off-by: Willem de Bruijn Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv6/reassembly.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 3815e8505ed2..e1da5b888cc4 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -211,7 +211,7 @@ static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb, { struct sk_buff *prev, *next; struct net_device *dev; - int offset, end; + int offset, end, fragsize; struct net *net = dev_net(skb_dst(skb)->dev); u8 ecn; @@ -336,6 +336,10 @@ found: fq->ecn |= ecn; add_frag_mem_limit(fq->q.net, skb->truesize); + fragsize = -skb_network_offset(skb) + skb->len; + if (fragsize > fq->q.max_size) + fq->q.max_size = fragsize; + /* The first fragment. * nhoffset is obtained from the first fragment, of course. */ @@ -495,6 +499,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn); IP6CB(head)->nhoff = nhoff; IP6CB(head)->flags |= IP6SKB_FRAGMENTED; + IP6CB(head)->frag_max_size = fq->q.max_size; /* Yes, and fold redundant checksum back. 8) */ skb_postpush_rcsum(head, skb_network_header(head), -- 2.20.1