text: /*
   * Copyright (c) 2007-2013 Nicira, Inc.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of version 2 of the GNU General Public
   * License as published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   * General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   * 02110-1301, USA
   */
  
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/if_vlan.h>
  #include <linux/in.h>
  #include <linux/in_route.h>
  #include <linux/inetdevice.h>
  #include <linux/jhash.h>
  #include <linux/list.h>
  #include <linux/kernel.h>
  #include <linux/version.h>
  #include <linux/workqueue.h>
  #include <linux/rculist.h>
  #include <net/ip_tunnels.h>
  #include <net/ip6_tunnel.h>
  #include <net/route.h>
  #include <net/xfrm.h>
  
  #include "compat.h"
  #include "gso.h"
  #include "vport-netdev.h"
  
  #ifndef USE_UPSTREAM_TUNNEL
  void rpl_iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
                        __be32 src, __be32 dst, __u8 proto, __u8 tos, __u8 ttl,
                        __be16 df, bool xnet)
  {
  	struct net_device *dev = skb->dev;
  	int pkt_len = skb->len - skb_inner_network_offset(skb);
  	struct iphdr *iph;
  	int err;
  
  	skb_scrub_packet(skb, xnet);
  
  	skb_clear_hash(skb);
  	skb_dst_set(skb, &rt->dst);
  
  #if 0
  	/* Do not clear ovs_skb_cb.  It will be done in gso code. */
  	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
  #endif
  
  	/* Push down and install the IP header. */
  	__skb_push(skb, sizeof(struct iphdr));
  	skb_reset_network_header(skb);
  
  	iph = ip_hdr(skb);
  
  	iph->version	=	4;
  	iph->ihl	=	sizeof(struct iphdr) >> 2;
  	iph->frag_off	=	df;
  	iph->protocol	=	proto;
  	iph->tos	=	tos;
  	iph->daddr	=	dst;
  	iph->saddr	=	src;
  	iph->ttl	=	ttl;
  
  #ifdef HAVE_IP_SELECT_IDENT_USING_DST_ENTRY
  	__ip_select_ident(iph, &rt->dst, (skb_shinfo(skb)->gso_segs ?: 1) - 1);
  #elif defined(HAVE_IP_SELECT_IDENT_USING_NET)
  	__ip_select_ident(dev_net(rt->dst.dev), iph,
  			  skb_shinfo(skb)->gso_segs ?: 1);
  #else
  	__ip_select_ident(iph, skb_shinfo(skb)->gso_segs ?: 1);
  #endif
  
  	err = ip_local_out(dev_net(rt->dst.dev), sk, skb);
  	if (unlikely(net_xmit_eval(err)))
  		pkt_len = 0;
  	iptunnel_xmit_stats(dev, pkt_len);
  }
  EXPORT_SYMBOL_GPL(rpl_iptunnel_xmit);
  
  int ovs_iptunnel_handle_offloads(struct sk_buff *skb,
  				 bool csum_help, int gso_type_mask,
  				 void (*fix_segment)(struct sk_buff *))
  {
  	int err;
  
  	if (likely(!skb_is_encapsulated(skb))) {
  		skb_reset_inner_headers(skb);
  		skb->encapsulation = 1;
  	} else if (skb_is_gso(skb)) {
  		err = -ENOSYS;
  		goto error;
  	}
  
  	if (skb_is_gso(skb)) {
  		err = skb_unclone(skb, GFP_ATOMIC);
  		if (unlikely(err))
  			goto error;
  		skb_shinfo(skb)->gso_type |= gso_type_mask;
  
  #ifndef USE_UPSTREAM_TUNNEL_GSO
  		if (gso_type_mask)
  			fix_segment = NULL;
  
  		OVS_GSO_CB(skb)->fix_segment = fix_segment;
  #endif
  		return 0;
  	}
  
  	/* If packet is not gso and we are resolving any partial checksum,
  	 * clear encapsulation flag. This allows setting CHECKSUM_PARTIAL
  	 * on the outer header without confusing devices that implement
  	 * NETIF_F_IP_CSUM with encapsulation.
  	 */
  	if (csum_help)
  		skb->encapsulation = 0;
  
  	if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) {
  		err = skb_checksum_help(skb);
  		if (unlikely(err))
  			goto error;
  	} else if (skb->ip_summed != CHECKSUM_PARTIAL)
  		skb->ip_summed = CHECKSUM_NONE;
  
  	return 0;
  error:
  	return err;
  }
  EXPORT_SYMBOL_GPL(ovs_iptunnel_handle_offloads);
  
  int rpl___iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
  			       __be16 inner_proto, bool raw_proto, bool xnet)
  {
  	if (unlikely(!pskb_may_pull(skb, hdr_len)))
  		return -ENOMEM;
  
  	skb_pull_rcsum(skb, hdr_len);
  
  	if (!raw_proto && inner_proto == htons(ETH_P_TEB)) {
  		struct ethhdr *eh;
  
  		if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
  			return -ENOMEM;
  
  		eh = (struct ethhdr *)skb->data;
  		if (likely(eth_proto_is_802_3(eh->h_proto)))
  			skb->protocol = eh->h_proto;
  		else
  			skb->protocol = htons(ETH_P_802_2);
  
  	} else {
  		skb->protocol = inner_proto;
  	}
  
  	skb_clear_hash_if_not_l4(skb);
  	skb->vlan_tci = 0;
  	skb_set_queue_mapping(skb, 0);
  	skb_scrub_packet(skb, xnet);
  
  	return iptunnel_pull_offloads(skb);
  }
  EXPORT_SYMBOL_GPL(rpl___iptunnel_pull_header);
  #endif /* USE_UPSTREAM_TUNNEL */
  
  bool ovs_skb_is_encapsulated(struct sk_buff *skb)
  {
  	/* checking for inner protocol should be sufficient on newer kernel, but
  	 * old kernel just set encapsulation bit.
  	 */
  	return ovs_skb_get_inner_protocol(skb) || skb->encapsulation;
  }
  EXPORT_SYMBOL_GPL(ovs_skb_is_encapsulated);
  
  /* derived from ip_tunnel_rcv(). */
  void ovs_ip_tunnel_rcv(struct net_device *dev, struct sk_buff *skb,
  		       struct metadata_dst *tun_dst)
  {
  	struct pcpu_sw_netstats *tstats;
  
  	tstats = this_cpu_ptr((struct pcpu_sw_netstats __percpu *)dev->tstats);
  	u64_stats_update_begin(&tstats->syncp);
  	tstats->rx_packets++;
  	tstats->rx_bytes += skb->len;
  	u64_stats_update_end(&tstats->syncp);
  
  	skb_reset_mac_header(skb);
  	skb_scrub_packet(skb, false);
  	skb->protocol = eth_type_trans(skb, dev);
  	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
  
  	ovs_skb_dst_set(skb, (struct dst_entry *)tun_dst);
  
  #ifndef USE_UPSTREAM_TUNNEL
  	netdev_port_receive(skb, &tun_dst->u.tun_info);
  #else
  	netif_rx(skb);
  #endif
  }
  
  #ifndef HAVE_PCPU_SW_NETSTATS
  #define netdev_stats_to_stats64 rpl_netdev_stats_to_stats64
  static void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
  				    const struct net_device_stats *netdev_stats)
  {
  #if BITS_PER_LONG == 64
  	BUILD_BUG_ON(sizeof(*stats64) != sizeof(*netdev_stats));
  	memcpy(stats64, netdev_stats, sizeof(*stats64));
  #else
  	size_t i, n = sizeof(*stats64) / sizeof(u64);
  	const unsigned long *src = (const unsigned long *)netdev_stats;
  	u64 *dst = (u64 *)stats64;
  
  	BUILD_BUG_ON(sizeof(*netdev_stats) / sizeof(unsigned long) !=
  		     sizeof(*stats64) / sizeof(u64));
  	for (i = 0; i < n; i++)
  		dst[i] = src[i];
  #endif
  }
  
  struct rtnl_link_stats64 *rpl_ip_tunnel_get_stats64(struct net_device *dev,
  						struct rtnl_link_stats64 *tot)
  {
  	int i;
  
  	netdev_stats_to_stats64(tot, &dev->stats);
  
  	for_each_possible_cpu(i) {
  		const struct pcpu_sw_netstats *tstats =
  						   per_cpu_ptr((struct pcpu_sw_netstats __percpu *)dev->tstats, i);
  		u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
  		unsigned int start;
  
  		do {
  			start = u64_stats_fetch_begin_irq(&tstats->syncp);
  			rx_packets = tstats->rx_packets;
  			tx_packets = tstats->tx_packets;
  			rx_bytes = tstats->rx_bytes;
  			tx_bytes = tstats->tx_bytes;
  		} while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
  
  		tot->rx_packets += rx_packets;
  		tot->tx_packets += tx_packets;
  		tot->rx_bytes   += rx_bytes;
  		tot->tx_bytes   += tx_bytes;
  	}
  
  	return tot;
  }
  #endif
  
  void rpl_ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb,
  		    struct net_device *dev)
  {
  	int pkt_len, err;
  
  	pkt_len = skb->len - skb_inner_network_offset(skb);
  #ifdef HAVE_IP6_LOCAL_OUT_SK
  	err = ip6_local_out_sk(sk, skb);
  #else
  	err = ip6_local_out(dev_net(skb_dst(skb)->dev), sk, skb);
  #endif
  	if (net_xmit_eval(err))
  		pkt_len = -1;
  
  	iptunnel_xmit_stats(dev, pkt_len);
  }
  EXPORT_SYMBOL_GPL(rpl_ip6tunnel_xmit);
  