12 files changed, 134 insertions, 2 deletions

diff --git a/net/Kconfig b/net/Kconfig
index 08de901415ee..523e43e6da1b 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -218,6 +218,7 @@ source "net/batman-adv/Kconfig"
 source "net/openvswitch/Kconfig"
 source "net/vmw_vsock/Kconfig"
 source "net/netlink/Kconfig"
+source "net/mpls/Kconfig"
 
 config RPS
         boolean
diff --git a/net/Makefile b/net/Makefile
index 091e7b04f301..9492e8cb64e9 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -70,3 +70,4 @@ obj-$(CONFIG_BATMAN_ADV)	+= batman-adv/
 obj-$(CONFIG_NFC)               += nfc/
 obj-$(CONFIG_OPENVSWITCH)       += openvswitch/
 obj-$(CONFIG_VSOCKETS)  += vmw_vsock/
+obj-$(CONFIG_NET_MPLS_GSO)      += mpls/
diff --git a/net/core/dev.c b/net/core/dev.c
index 50c02ded1d69..2f09cb29cc95 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5277,6 +5277,10 @@ int register_netdevice(struct net_device *dev)
          */
         dev->hw_enc_features |= NETIF_F_SG;
 
+        /* Make NETIF_F_SG inheritable to MPLS.
+         */
+        dev->mpls_features |= NETIF_F_SG;
+
         ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
         ret = notifier_to_errno(ret);
         if (ret)
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 22efdaa76ebf..4e6f63ade741 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -82,6 +82,7 @@ static const char netdev_features_strings[NETDEV_FEATURE_COUNT][ETH_GSTRING_LEN]
         [NETIF_F_FSO_BIT] =              "tx-fcoe-segmentation",
         [NETIF_F_GSO_GRE_BIT] =          "tx-gre-segmentation",
         [NETIF_F_GSO_UDP_TUNNEL_BIT] =   "tx-udp_tnl-segmentation",
+        [NETIF_F_GSO_MPLS_BIT] =         "tx-mpls-segmentation",
 
         [NETIF_F_FCOE_CRC_BIT] =         "tx-checksum-fcoe-crc",
         [NETIF_F_SCTP_CSUM_BIT] =        "tx-checksum-sctp",
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index d01be2a3ae53..b05ae96aec44 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1295,6 +1295,7 @@ static struct sk_buff *inet_gso_segment(struct sk_buff *skb,
                        SKB_GSO_GRE |
                        SKB_GSO_TCPV6 |
                        SKB_GSO_UDP_TUNNEL |
+                       SKB_GSO_MPLS |
                        0)))
                 goto out;
 
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index d87ce72ca8aa..ba4186e1dca9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2917,6 +2917,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb,
                                SKB_GSO_TCP_ECN |
                                SKB_GSO_TCPV6 |
                                SKB_GSO_GRE |
+                               SKB_GSO_MPLS |
                                SKB_GSO_UDP_TUNNEL |
                                0) ||
                              !(type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))))
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 0bf5d399a03c..aa5eff46d137 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2381,7 +2381,7 @@ 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_GRE) ||
+                                      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 71b766ee821d..a263b990ee11 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -98,6 +98,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
                        SKB_GSO_TCP_ECN |
                        SKB_GSO_GRE |
                        SKB_GSO_UDP_TUNNEL |
+                       SKB_GSO_MPLS |
                        SKB_GSO_TCPV6 |
                        0)))
                 goto out;
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 3bb3a891a424..76d401a93c7a 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -63,7 +63,8 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
                 if (unlikely(type & ~(SKB_GSO_UDP |
                                       SKB_GSO_DODGY |
                                       SKB_GSO_UDP_TUNNEL |
-                                      SKB_GSO_GRE) ||
+                                      SKB_GSO_GRE |
+                                      SKB_GSO_MPLS) ||
                              !(type & (SKB_GSO_UDP))))
                         goto out;
 
diff --git a/net/mpls/Kconfig b/net/mpls/Kconfig
new file mode 100644
index 000000000000..37421db88965
--- /dev/null
+++ b/net/mpls/Kconfig
@@ -0,0 +1,9 @@
+#
+# MPLS configuration
+#
+config NET_MPLS_GSO
+        tristate "MPLS: GSO support"
+        help
+         This is helper module to allow segmentation of non-MPLS GSO packets
+         that have had MPLS stack entries pushed onto them and thus
+         become MPLS GSO packets.
diff --git a/net/mpls/Makefile b/net/mpls/Makefile
new file mode 100644
index 000000000000..0a3c171be537
--- /dev/null
+++ b/net/mpls/Makefile
@@ -0,0 +1,4 @@
+#
+# Makefile for MPLS.
+#
+obj-y += mpls_gso.o
diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c
new file mode 100644
index 000000000000..1bec1219ab81
--- /dev/null
+++ b/net/mpls/mpls_gso.c
@@ -0,0 +1,108 @@
+/*
+ *      MPLS GSO Support
+ *
+ *      Authors: Simon Horman (horms@verge.net.au)
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ *      Based on: GSO portions of net/ipv4/gre.c
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/netdev_features.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+
+static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
+                                       netdev_features_t features)
+{
+        struct sk_buff *segs = ERR_PTR(-EINVAL);
+        netdev_features_t mpls_features;
+        __be16 mpls_protocol;
+
+        if (unlikely(skb_shinfo(skb)->gso_type &
+                                ~(SKB_GSO_TCPV4 |
+                                  SKB_GSO_TCPV6 |
+                                  SKB_GSO_UDP |
+                                  SKB_GSO_DODGY |
+                                  SKB_GSO_TCP_ECN |
+                                  SKB_GSO_GRE |
+                                  SKB_GSO_MPLS)))
+                goto out;
+
+        /* Setup inner SKB. */
+        mpls_protocol = skb->protocol;
+        skb->protocol = skb->inner_protocol;
+
+        /* Push back the mac header that skb_mac_gso_segment() has pulled.
+         * It will be re-pulled by the call to skb_mac_gso_segment() below
+         */
+        __skb_push(skb, skb->mac_len);
+
+        /* Segment inner packet. */
+        mpls_features = skb->dev->mpls_features & netif_skb_features(skb);
+        segs = skb_mac_gso_segment(skb, mpls_features);
+
+
+        /* Restore outer protocol. */
+        skb->protocol = mpls_protocol;
+
+        /* Re-pull the mac header that the call to skb_mac_gso_segment()
+         * above pulled.  It will be re-pushed after returning
+         * skb_mac_gso_segment(), an indirect caller of this function.
+         */
+        __skb_push(skb, skb->data - skb_mac_header(skb));
+
+out:
+        return segs;
+}
+
+static int mpls_gso_send_check(struct sk_buff *skb)
+{
+        return 0;
+}
+
+static struct packet_offload mpls_mc_offload = {
+        .type = cpu_to_be16(ETH_P_MPLS_MC),
+        .callbacks = {
+                .gso_send_check =       mpls_gso_send_check,
+                .gso_segment    =       mpls_gso_segment,
+        },
+};
+
+static struct packet_offload mpls_uc_offload = {
+        .type = cpu_to_be16(ETH_P_MPLS_UC),
+        .callbacks = {
+                .gso_send_check =       mpls_gso_send_check,
+                .gso_segment    =       mpls_gso_segment,
+        },
+};
+
+static int __init mpls_gso_init(void)
+{
+        pr_info("MPLS GSO support\n");
+
+        dev_add_offload(&mpls_uc_offload);
+        dev_add_offload(&mpls_mc_offload);
+
+        return 0;
+}
+
+static void __exit mpls_gso_exit(void)
+{
+        dev_remove_offload(&mpls_uc_offload);
+        dev_remove_offload(&mpls_mc_offload);
+}
+
+module_init(mpls_gso_init);
+module_exit(mpls_gso_exit);
+
+MODULE_DESCRIPTION("MPLS GSO support");
+MODULE_AUTHOR("Simon Horman (horms@verge.net.au)");
+MODULE_LICENSE("GPL");