text: /*
   * Copyright (c) 2014 Nicira, Inc.
   *
   * 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.
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/in.h>
  #include <linux/ip.h>
  #include <linux/net.h>
  #include <linux/rculist.h>
  #include <linux/udp.h>
  #include <linux/if_vlan.h>
  #include <linux/module.h>
  
  #include <net/geneve.h>
  #include <net/icmp.h>
  #include <net/ip.h>
  #include <net/route.h>
  #include <net/udp.h>
  #include <net/xfrm.h>
  
  #include "datapath.h"
  #include "vport.h"
  
  static struct vport_ops ovs_geneve_vport_ops;
  
  /**
   * struct geneve_port - Keeps track of open UDP ports
   * @gs: The socket created for this port number.
   * @name: vport name.
   */
  struct geneve_port {
  	struct geneve_sock *gs;
  	char name[IFNAMSIZ];
  };
  
  static LIST_HEAD(geneve_ports);
  
  static inline struct geneve_port *geneve_vport(const struct vport *vport)
  {
  	return vport_priv(vport);
  }
  
  static inline struct genevehdr *geneve_hdr(const struct sk_buff *skb)
  {
  	return (struct genevehdr *)(udp_hdr(skb) + 1);
  }
  
  /* Convert 64 bit tunnel ID to 24 bit VNI. */
  static void tunnel_id_to_vni(__be64 tun_id, __u8 *vni)
  {
  #ifdef __BIG_ENDIAN
  	vni[0] = (__force __u8)(tun_id >> 16);
  	vni[1] = (__force __u8)(tun_id >> 8);
  	vni[2] = (__force __u8)tun_id;
  #else
  	vni[0] = (__force __u8)((__force u64)tun_id >> 40);
  	vni[1] = (__force __u8)((__force u64)tun_id >> 48);
  	vni[2] = (__force __u8)((__force u64)tun_id >> 56);
  #endif
  }
  
  /* Convert 24 bit VNI to 64 bit tunnel ID. */
  static __be64 vni_to_tunnel_id(const __u8 *vni)
  {
  #ifdef __BIG_ENDIAN
  	return (vni[0] << 16) | (vni[1] << 8) | vni[2];
  #else
  	return (__force __be64)(((__force u64)vni[0] << 40) |
  				((__force u64)vni[1] << 48) |
  				((__force u64)vni[2] << 56));
  #endif
  }
  
  static void geneve_rcv(struct geneve_sock *gs, struct sk_buff *skb)
  {
  	struct vport *vport = gs->rcv_data;
  	struct genevehdr *geneveh = geneve_hdr(skb);
  	int opts_len;
  	struct ovs_tunnel_info tun_info;
  	__be64 key;
  	__be16 flags;
  
  	opts_len = geneveh->opt_len * 4;
  
  	flags = TUNNEL_KEY | TUNNEL_GENEVE_OPT |
  		(udp_hdr(skb)->check != 0 ? TUNNEL_CSUM : 0) |
  		(geneveh->oam ? TUNNEL_OAM : 0) |
  		(geneveh->critical ? TUNNEL_CRIT_OPT : 0);
  
  	key = vni_to_tunnel_id(geneveh->vni);
  
  	ovs_flow_tun_info_init(&tun_info, ip_hdr(skb),
  			       udp_hdr(skb)->source, udp_hdr(skb)->dest,
  			       key, flags,
  			       geneveh->options, opts_len);
  
  	ovs_vport_receive(vport, skb, &tun_info, false);
  }
  
  static int geneve_get_options(const struct vport *vport,
  			      struct sk_buff *skb)
  {
  	struct geneve_port *geneve_port = geneve_vport(vport);
  	__be16 dst_port = inet_sport(geneve_port->gs->sock->sk);
  
  	if (nla_put_u16(skb, OVS_TUNNEL_ATTR_DST_PORT, ntohs(dst_port)))
  		return -EMSGSIZE;
  	return 0;
  }
  
  static void geneve_tnl_destroy(struct vport *vport)
  {
  	struct geneve_port *geneve_port = geneve_vport(vport);
  
  	geneve_sock_release(geneve_port->gs);
  
  	ovs_vport_deferred_free(vport);
  }
  
  static struct vport *geneve_tnl_create(const struct vport_parms *parms)
  {
  	struct net *net = ovs_dp_get_net(parms->dp);
  	struct nlattr *options = parms->options;
  	struct geneve_port *geneve_port;
  	struct geneve_sock *gs;
  	struct vport *vport;
  	struct nlattr *a;
  	int err;
  	u16 dst_port;
  
  	if (!options) {
  		err = -EINVAL;
  		goto error;
  	}
  
  	a = nla_find_nested(options, OVS_TUNNEL_ATTR_DST_PORT);
  	if (a && nla_len(a) == sizeof(u16)) {
  		dst_port = nla_get_u16(a);
  	} else {
  		/* Require destination port from userspace. */
  		err = -EINVAL;
  		goto error;
  	}
  
  	vport = ovs_vport_alloc(sizeof(struct geneve_port),
  				&ovs_geneve_vport_ops, parms);
  	if (IS_ERR(vport))
  		return vport;
  
  	geneve_port = geneve_vport(vport);
  	strncpy(geneve_port->name, parms->name, IFNAMSIZ);
  
  	gs = geneve_sock_add(net, htons(dst_port), geneve_rcv, vport, true, 0);
  	if (IS_ERR(gs)) {
  		ovs_vport_free(vport);
  		return (void *)gs;
  	}
  	geneve_port->gs = gs;
  
  	return vport;
  error:
  	return ERR_PTR(err);
  }
  
  static int geneve_tnl_send(struct vport *vport, struct sk_buff *skb)
  {
  	const struct ovs_key_ipv4_tunnel *tun_key;
  	struct ovs_tunnel_info *tun_info;
  	struct net *net = ovs_dp_get_net(vport->dp);
  	struct geneve_port *geneve_port = geneve_vport(vport);
  	__be16 dport = inet_sport(geneve_port->gs->sock->sk);
  	__be16 sport;
  	__be32 saddr;
  	struct rtable *rt;
  	u8 vni[3], opts_len, *opts;
  	__be16 df;
  	int err;
  
  	tun_info = OVS_CB(skb)->egress_tun_info;
  	if (unlikely(!tun_info)) {
  		err = -EINVAL;
  		goto error;
  	}
  
  	tun_key = &tun_info->tunnel;
  
  	/* Reject layer 3 packets */
  	if (unlikely(skb->mac_len == 0))
  		return -EINVAL;
  
  	saddr = tun_key->ipv4_src;
  	rt = find_route(ovs_dp_get_net(vport->dp),
  			&saddr, tun_key->ipv4_dst,
  			IPPROTO_UDP, tun_key->ipv4_tos,
  			skb->mark);
  	if (IS_ERR(rt)) {
  		err = PTR_ERR(rt);
  		goto error;
  	}
  
  	df = tun_key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
  	sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
  	tunnel_id_to_vni(tun_key->tun_id, vni);
  	skb->ignore_df = 1;
  
  	if (tun_key->tun_flags & TUNNEL_GENEVE_OPT) {
  		opts = (u8 *)tun_info->options;
  		opts_len = tun_info->options_len;
  	} else {
  		opts = NULL;
  		opts_len = 0;
  	}
  
  	err = geneve_xmit_skb(geneve_port->gs, rt, skb, saddr,
  			      tun_key->ipv4_dst, tun_key->ipv4_tos,
  			      tun_key->ipv4_ttl, df, sport, dport,
  			      tun_key->tun_flags, vni, opts_len, opts,
  			      !!(tun_key->tun_flags & TUNNEL_CSUM), false);
  	if (err < 0)
  		ip_rt_put(rt);
  	return err;
  
  error:
  	kfree_skb(skb);
  	return err;
  }
  
  static const char *geneve_get_name(const struct vport *vport)
  {
  	struct geneve_port *geneve_port = geneve_vport(vport);
  
  	return geneve_port->name;
  }
  
  static int geneve_get_egress_tun_info(struct vport *vport, struct sk_buff *skb,
  				      struct ovs_tunnel_info *egress_tun_info)
  {
  	struct geneve_port *geneve_port = geneve_vport(vport);
  	struct net *net = ovs_dp_get_net(vport->dp);
  	__be16 dport = inet_sport(geneve_port->gs->sock->sk);
  	__be16 sport = udp_flow_src_port(net, skb, 1, USHRT_MAX, true);
  
  	/* Get tp_src and tp_dst, refert to geneve_build_header().
  	 */
  	return ovs_tunnel_get_egress_info(egress_tun_info,
  					  ovs_dp_get_net(vport->dp),
  					  OVS_CB(skb)->egress_tun_info,
  					  IPPROTO_UDP, skb->mark, sport, dport);
  }
  
  static struct vport_ops ovs_geneve_vport_ops = {
  	.type			= OVS_VPORT_TYPE_GENEVE,
  	.create			= geneve_tnl_create,
  	.destroy		= geneve_tnl_destroy,
  	.get_name		= geneve_get_name,
  	.get_options		= geneve_get_options,
  	.send			= geneve_tnl_send,
  	.get_egress_tun_info	= geneve_get_egress_tun_info,
  	.owner			= THIS_MODULE,
  };
  
  static int __init ovs_geneve_tnl_init(void)
  {
  	return ovs_vport_ops_register(&ovs_geneve_vport_ops);
  }
  
  static void __exit ovs_geneve_tnl_exit(void)
  {
  	ovs_vport_ops_unregister(&ovs_geneve_vport_ops);
  }
  
  module_init(ovs_geneve_tnl_init);
  module_exit(ovs_geneve_tnl_exit);
  
  MODULE_DESCRIPTION("OVS: Geneve swiching port");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("vport-type-5");
  