/* * 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))) 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 & features; 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_pull(skb, skb->data - skb_mac_header(skb)); out: return segs; } static struct packet_offload mpls_mc_offload __read_mostly = { .type = cpu_to_be16(ETH_P_MPLS_MC), .callbacks = { .gso_segment = mpls_gso_segment, }, }; static struct packet_offload mpls_uc_offload __read_mostly = { .type = cpu_to_be16(ETH_P_MPLS_UC), .callbacks = { .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");