ipip: add GSO/TSO support

Now inet_gso_segment() is stackable, its relatively easy to
implement GSO/TSO support for IPIP

Performance results, when segmentation is done after tunnel
device (as no NIC is yet enabled for TSO IPIP support) :

Before patch :

lpq83:~# ./netperf -H 7.7.9.84 -Cc
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 7.7.9.84 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  16384  16384    10.00      3357.88   5.09     3.70     2.983   2.167

After patch :

lpq83:~# ./netperf -H 7.7.9.84 -Cc
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 7.7.9.84 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

 87380  16384  16384    10.00      7710.19   4.52     6.62     1.152   1.687

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

11 files changed, 29 insertions, 8 deletions

diff --git a/include/linux/netdev_features.h b/include/linux/netdev_features.h
index a2a89a5c7be5..8dad68cede1c 100644
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -42,6 +42,7 @@ enum {
         NETIF_F_TSO6_BIT,               /* ... TCPv6 segmentation */
         NETIF_F_FSO_BIT,                /* ... FCoE segmentation */
         NETIF_F_GSO_GRE_BIT,            /* ... GRE with TSO */
+        NETIF_F_GSO_IPIP_BIT,           /* ... IPIP tunnel with TSO */
         NETIF_F_GSO_UDP_TUNNEL_BIT,     /* ... UDP TUNNEL with TSO */
         NETIF_F_GSO_MPLS_BIT,           /* ... MPLS segmentation */
         /**/NETIF_F_GSO_LAST =          /* last bit, see GSO_MASK */
@@ -107,6 +108,7 @@ enum {
 #define NETIF_F_RXFCS           __NETIF_F(RXFCS)
 #define NETIF_F_RXALL           __NETIF_F(RXALL)
 #define NETIF_F_GSO_GRE         __NETIF_F(GSO_GRE)
+#define NETIF_F_GSO_IPIP        __NETIF_F(GSO_IPIP)
 #define NETIF_F_GSO_UDP_TUNNEL  __NETIF_F(GSO_UDP_TUNNEL)
 #define NETIF_F_GSO_MPLS        __NETIF_F(GSO_MPLS)
 #define NETIF_F_HW_VLAN_STAG_FILTER __NETIF_F(HW_VLAN_STAG_FILTER)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index cad1e0c5cc04..60729134d253 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -318,9 +318,11 @@ enum {
 
         SKB_GSO_GRE = 1 << 6,
 
-        SKB_GSO_UDP_TUNNEL = 1 << 7,
+        SKB_GSO_IPIP = 1 << 7,
 
-        SKB_GSO_MPLS = 1 << 8,
+        SKB_GSO_UDP_TUNNEL = 1 << 8,
+
+        SKB_GSO_MPLS = 1 << 9,
 };
 
 #if BITS_PER_LONG > 32
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 78e9d9223e40..8cab7744790e 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -81,6 +81,7 @@ static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN]
         [NETIF_F_TSO6_BIT] =             "tx-tcp6-segmentation",
         [NETIF_F_FSO_BIT] =              "tx-fcoe-segmentation",
         [NETIF_F_GSO_GRE_BIT] =          "tx-gre-segmentation",
+        [NETIF_F_GSO_IPIP_BIT] =         "tx-ipip-segmentation",
         [NETIF_F_GSO_UDP_TUNNEL_BIT] =   "tx-udp_tnl-segmentation",
         [NETIF_F_GSO_MPLS_BIT] =         "tx-mpls-segmentation",
 
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5783ab5b5ef8..4049906010f7 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1291,6 +1291,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
                        SKB_GSO_DODGY |
                        SKB_GSO_TCP_ECN |
                        SKB_GSO_GRE |
+                       SKB_GSO_IPIP |
                        SKB_GSO_TCPV6 |
                        SKB_GSO_UDP_TUNNEL |
                        SKB_GSO_MPLS |
@@ -1656,6 +1657,13 @@ static struct packet_offload ip_packet_offload __read_mostly = {
         },
 };
 
+static const struct net_offload ipip_offload = {
+        .callbacks = {
+                .gso_send_check = inet_gso_send_check,
+                .gso_segment    = inet_gso_segment,
+        },
+};
+
 static int __init ipv4_offload_init(void)
 {
         /*
@@ -1667,6 +1675,7 @@ static int __init ipv4_offload_init(void)
                 pr_crit("%s: Cannot add TCP protocol offload\n", __func__);
 
         dev_add_offload(&ip_packet_offload);
+        inet_add_offload(&ipip_offload, IPPROTO_IPIP);
         return 0;
 }
 
diff --git a/net/ipv4/gre_offload.c b/net/ipv4/gre_offload.c
index 55e6bfb3a289..e5d436188464 100644
--- a/net/ipv4/gre_offload.c
+++ b/net/ipv4/gre_offload.c
@@ -39,7 +39,8 @@ static struct sk_buff *gre_gso_segment(struct sk_buff *skb,
                                   SKB_GSO_UDP |
                                   SKB_GSO_DODGY |
                                   SKB_GSO_TCP_ECN |
-                                  SKB_GSO_GRE)))
+                                  SKB_GSO_GRE |
+                                  SKB_GSO_IPIP)))
                 goto out;
 
         if (unlikely(!pskb_may_pull(skb, sizeof(*greh))))
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 7f80fb4b82d3..fe3e9f7f1f0b 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -220,17 +220,17 @@ static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
         if (unlikely(skb->protocol != htons(ETH_P_IP)))
                 goto tx_error;
 
-        if (likely(!skb->encapsulation)) {
-                skb_reset_inner_headers(skb);
-                skb->encapsulation = 1;
-        }
+        skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);
+        if (IS_ERR(skb))
+                goto out;
 
         ip_tunnel_xmit(skb, dev, tiph, tiph->protocol);
         return NETDEV_TX_OK;
 
 tx_error:
-        dev->stats.tx_errors++;
         dev_kfree_skb(skb);
+out:
+        dev->stats.tx_errors++;
         return NETDEV_TX_OK;
 }
 
@@ -275,6 +275,7 @@ static const struct net_device_ops ipip_netdev_ops = {
 #define IPIP_FEATURES (NETIF_F_SG |             \
                        NETIF_F_FRAGLIST |       \
                        NETIF_F_HIGHDMA |        \
+                       NETIF_F_GSO_SOFTWARE |   \
                        NETIF_F_HW_CSUM)
 
 static void ipip_tunnel_setup(struct net_device *dev)
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 8e3113f46ec1..dfc96b00673e 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -56,6 +56,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
                                SKB_GSO_TCP_ECN |
                                SKB_GSO_TCPV6 |
                                SKB_GSO_GRE |
+                               SKB_GSO_IPIP |
                                SKB_GSO_MPLS |
                                SKB_GSO_UDP_TUNNEL |
                                0) ||
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index f35eccaa855e..83206de2bc76 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -52,6 +52,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
 
                 if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY |
                                       SKB_GSO_UDP_TUNNEL |
+                                      SKB_GSO_IPIP |
                                       SKB_GSO_GRE | SKB_GSO_MPLS) ||
                              !(type & (SKB_GSO_UDP))))
                         goto out;
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index b405fba91c72..5c2fc1d04196 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -96,6 +96,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
                        SKB_GSO_DODGY |
                        SKB_GSO_TCP_ECN |
                        SKB_GSO_GRE |
+                       SKB_GSO_IPIP |
                        SKB_GSO_UDP_TUNNEL |
                        SKB_GSO_MPLS |
                        SKB_GSO_TCPV6 |
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 60559511bd9c..f63780ff3732 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -64,6 +64,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
                                       SKB_GSO_DODGY |
                                       SKB_GSO_UDP_TUNNEL |
                                       SKB_GSO_GRE |
+                                      SKB_GSO_IPIP |
                                       SKB_GSO_MPLS) ||
                              !(type & (SKB_GSO_UDP))))
                         goto out;
diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c
index 1bec1219ab81..851cd880b0c0 100644
--- a/net/mpls/mpls_gso.c
+++ b/net/mpls/mpls_gso.c
@@ -33,6 +33,7 @@ static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
                                   SKB_GSO_DODGY |
                                   SKB_GSO_TCP_ECN |
                                   SKB_GSO_GRE |
+                                  SKB_GSO_IPIP |
                                   SKB_GSO_MPLS)))
                 goto out;