Commit 9669fffc authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: ensure correct skb->tstamp in various fragmenters 



Thomas found that some forwarded packets would be stuck
in FQ packet scheduler because their skb->tstamp contained
timestamps far in the future.

We thought we addressed this point in commit 8203e2d8
("net: clear skb->tstamp in forwarding paths") but there
is still an issue when/if a packet needs to be fragmented.

In order to meet EDT requirements, we have to make sure all
fragments get the original skb->tstamp.

Note that this original skb->tstamp should be zero in
forwarding path, but might have a non zero value in
output path if user decided so.

Fixes: fb420d5d ("tcp/fq: move back to CLOCK_MONOTONIC")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reported-by: default avatarThomas Bartschies <Thomas.Bartschies@cvk.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 63158ac0

net/bridge/netfilter/nf_conntrack_bridge.c

+3 −0
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ static int nf_br_ip_fragment(struct net *net, struct sock *sk, 
{

	int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;

	unsigned int hlen, ll_rs, mtu;

	ktime_t tstamp = skb->tstamp;

	struct ip_frag_state state;

	struct iphdr *iph;

	int err;
@@ -80,6 +81,7 @@ static int nf_br_ip_fragment(struct net *net, struct sock *sk, 
			if (iter.frag)

				ip_fraglist_prepare(skb, &iter);



			skb->tstamp = tstamp;

			err = output(net, sk, data, skb);

			if (err || !iter.frag)

				break;
@@ -104,6 +106,7 @@ slow_path: 
			goto blackhole;

		}



		skb2->tstamp = tstamp;

		err = output(net, sk, data, skb2);

		if (err)

			goto blackhole;

net/ipv4/ip_output.c

+3 −0
Original line number Diff line number Diff line
@@ -771,6 +771,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 
	struct rtable *rt = skb_rtable(skb);

	unsigned int mtu, hlen, ll_rs;

	struct ip_fraglist_iter iter;

	ktime_t tstamp = skb->tstamp;

	struct ip_frag_state state;

	int err = 0;
@@ -846,6 +847,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 
				ip_fraglist_prepare(skb, &iter);

			}



			skb->tstamp = tstamp;

			err = output(net, sk, skb);



			if (!err)
@@ -900,6 +902,7 @@ slow_path: 
		/*

		 *	Put this fragment into the sending queue.

		 */

		skb2->tstamp = tstamp;

		err = output(net, sk, skb2);

		if (err)

			goto fail;

net/ipv6/ip6_output.c

+3 −0
Original line number Diff line number Diff line
@@ -768,6 +768,7 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 
				inet6_sk(skb->sk) : NULL;

	struct ip6_frag_state state;

	unsigned int mtu, hlen, nexthdr_offset;

	ktime_t tstamp = skb->tstamp;

	int hroom, err = 0;

	__be32 frag_id;

	u8 *prevhdr, nexthdr = 0;
@@ -855,6 +856,7 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 
			if (iter.frag)

				ip6_fraglist_prepare(skb, &iter);



			skb->tstamp = tstamp;

			err = output(net, sk, skb);

			if (!err)

				IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
@@ -913,6 +915,7 @@ slow_path: 
		/*

		 *	Put this fragment into the sending queue.

		 */

		frag->tstamp = tstamp;

		err = output(net, sk, frag);

		if (err)

			goto fail;

net/ipv6/netfilter.c

+3 −0
Original line number Diff line number Diff line
@@ -119,6 +119,7 @@ int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 
				  struct sk_buff *))

{

	int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;

	ktime_t tstamp = skb->tstamp;

	struct ip6_frag_state state;

	u8 *prevhdr, nexthdr = 0;

	unsigned int mtu, hlen;
@@ -183,6 +184,7 @@ int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, 
			if (iter.frag)

				ip6_fraglist_prepare(skb, &iter);



			skb->tstamp = tstamp;

			err = output(net, sk, data, skb);

			if (err || !iter.frag)

				break;
@@ -215,6 +217,7 @@ slow_path: 
			goto blackhole;

		}



		skb2->tstamp = tstamp;

		err = output(net, sk, data, skb2);

		if (err)

			goto blackhole;

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