Patch "tunnels: Remove encapsulation offloads on decap." has been added to the 4.4-stable tree
Subsystems (3)
This is a note to let you know that I've just added the patch titled
tunnels: Remove encapsulation offloads on decap.
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tunnels-remove-encapsulation-offloads-on-decap.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
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From
a09a4c8dd1ec7f830e1fb9e59eb72bddc965d168Mon Sep 17 00:00:00 2001
From: Jesse Gross <[email protected]>
Date: Sat, 19 Mar 2016 09:32:02 -0700
Subject: tunnels: Remove encapsulation offloads on decap.
From: Jesse Gross <[email protected]>
commit a09a4c8dd1ec7f830e1fb9e59eb72bddc965d168 upstream.
If a packet is either locally encapsulated or processed through GRO it is marked with the offloads that it requires. However, when it is decapsulated these tunnel offload indications are not removed. This means that if we receive an encapsulated TCP packet, aggregate it with GRO, decapsulate, and retransmit the resulting frame on a NIC that does not support encapsulation, we won't be able to take advantage of hardware offloads even though it is just a simple TCP packet at this point.
This fixes the problem by stripping off encapsulation offload indications when packets are decapsulated.
The performance impacts of this bug are significant. In a test where a Geneve encapsulated TCP stream is sent to a hypervisor, GRO'ed, decapsulated, and bridged to a VM performance is improved by 60% (5Gbps->8Gbps) as a result of avoiding unnecessary segmentation at the VM tap interface.
--- include/net/ip_tunnels.h | 16 ++++++++++++++++ net/ipv4/fou.c | 13 +++++++++++-- net/ipv4/ip_tunnel_core.c | 3 ++- net/ipv6/sit.c | 5 +++-- 4 files changed, 32 insertions(+), 5 deletions(-)
include/net/ip_tunnels.h +16 -0
@@ -283,6 +283,22 @@ struct metadata_dst *iptunnel_metadata_rstruct sk_buff *iptunnel_handle_offloads (struct sk_buff *skb,bool gre_csum,int gso_type_mask); +static inline int iptunnel_pull_offloads (struct sk_buff *skb) +{ +if (skb_is_gso (skb)) { +int err; + + err =skb_unclone (skb,GFP_ATOMIC ); +if (unlikely (err)) +return err; +skb_shinfo (skb)->gso_type &= ~(NETIF_F_GSO_ENCAP_ALL >> +NETIF_F_GSO_SHIFT ); + } + + skb->encapsulation =0 ; +return 0 ; +} +static inline void iptunnel_xmit_stats (int err,struct net_device_stats *err_stats,struct pcpu_sw_netstats __percpu *stats)
net/ipv4/fou.c +11 -2
@@ -48,7 +48,7 @@ static inline struct fou *fou_from_sock(return sk->sk_user_data; } -static void fou_recv_pull (struct sk_buff *skb,size_t len) +static int fou_recv_pull (struct sk_buff *skb,size_t len) {struct iphdr *iph =ip_hdr (skb);
@@ -59,6 +59,7 @@ static void fou_recv_pull(struct sk_buff__skb_pull (skb, len);skb_postpull_rcsum (skb,udp_hdr (skb), len);skb_reset_transport_header (skb); +return iptunnel_pull_offloads (skb); }static int fou_udp_recv (struct sock *sk,struct sk_buff *skb)
@@ -68,9 +69,14 @@ static int fou_udp_recv(struct sock *sk,if (!fou)return 1 ; -fou_recv_pull (skb,sizeof (struct udphdr )); +if (fou_recv_pull (skb,sizeof (struct udphdr ))) + goto drop;return -fou->protocol; + +drop: +kfree_skb (skb); +return 0 ; } static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr,
@@ -170,6 +176,9 @@ static int gue_udp_recv(struct sock *sk,__skb_pull (skb,sizeof (struct udphdr ) + hdrlen);skb_reset_transport_header (skb); +if (iptunnel_pull_offloads (skb)) + goto drop; +return -guehdr->proto_ctype; drop:
net/ipv4/ip_tunnel_core.c +2 -1
@@ -116,7 +116,8 @@ int iptunnel_pull_header(struct sk_buff skb->vlan_tci =0 ;skb_set_queue_mapping (skb,0 ); skb->pkt_type =PACKET_HOST ; -return 0 ; + +return iptunnel_pull_offloads (skb); }EXPORT_SYMBOL_GPL (iptunnel_pull_header);
net/ipv6/sit.c +3 -2
@@ -681,14 +681,15 @@ static int ipip6_rcv(struct sk_buff *skb skb->mac_header = skb->network_header;skb_reset_network_header (skb);IPCB (skb)->flags =0 ; - skb->protocol =htons (ETH_P_IPV6 ); + skb->dev = tunnel->dev;if (packet_is_spoofed (skb, iph, tunnel)) { tunnel->dev->stats.rx_errors++; goto out; } -__skb_tunnel_rx (skb, tunnel->dev, tunnel->net); +if (iptunnel_pull_header (skb,0 ,htons (ETH_P_IPV6 ))) + goto out; err =IP_ECN_decapsulate (iph, skb);if (unlikely (err)) {
Patches currently in stable-queue which might be from [email protected] are
queue-4.4/tunnels-remove-encapsulation-offloads-on-decap.patch queue-4.4/tunnels-don-t-apply-gro-to-multiple-layers-of-encapsulation.patch queue-4.4/ipip-properly-mark-ipip-gro-packets-as-encapsulated.patch