ipv6: on reassembly, record frag_max_size (dbd1759e) · Commits · 戴 / test

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 <willemb@google.com> Acked-by:

Eric Dumazet <edumazet@google.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv6/reassembly.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -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),

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