Commit 8c3a897b authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

inet: restore gso for vxlan 



Alexei reported a performance regression on vxlan, caused
by commit 3347c960 "ipv4: gso: make inet_gso_segment() stackable"

GSO vxlan packets were not properly segmented, adding IP fragments
while they were not expected.

Rename 'bool tunnel' to 'bool encap', and add a new boolean
to express the fact that UDP should be fragmented.
This fragmentation is triggered by skb->encapsulation being set.

Remove a "skb->encapsulation = 1" added in above commit,
as its not needed, as frags inherit skb->frag from original
GSO skb.

Reported-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Tested-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1f2cd845

net/ipv4/af_inet.c

+7 −8
Original line number Diff line number Diff line
@@ -1251,8 +1251,8 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, 
	struct sk_buff *segs = ERR_PTR(-EINVAL);

	const struct net_offload *ops;

	unsigned int offset = 0;

	bool udpfrag, encap;

	struct iphdr *iph;

	bool tunnel;

	int proto;

	int nhoff;

	int ihl;
@@ -1290,8 +1290,8 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, 
		goto out;

	__skb_pull(skb, ihl);



	tunnel = SKB_GSO_CB(skb)->encap_level > 0;

	if (tunnel)

	encap = SKB_GSO_CB(skb)->encap_level > 0;

	if (encap)

		features = skb->dev->hw_enc_features & netif_skb_features(skb);

	SKB_GSO_CB(skb)->encap_level += ihl;
@@ -1306,10 +1306,11 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, 
	if (IS_ERR_OR_NULL(segs))

		goto out;



	udpfrag = !!skb->encapsulation && proto == IPPROTO_UDP;

	skb = segs;

	do {

		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);

		if (!tunnel && proto == IPPROTO_UDP) {

		if (udpfrag) {

			iph->id = htons(id);

			iph->frag_off = htons(offset >> 3);

			if (skb->next != NULL)
@@ -1320,10 +1321,8 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb, 
		}

		iph->tot_len = htons(skb->len - nhoff);

		ip_send_check(iph);

		if (tunnel) {

		if (encap)

			skb_reset_inner_headers(skb);

			skb->encapsulation = 1;

		}

		skb->network_header = (u8 *)iph - skb->head;

	} while ((skb = skb->next));

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