text: /*
   * Copyright (c) 2007-2012 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
   */
  
  #ifndef TUNNEL_H
  #define TUNNEL_H 1
  
  #include <linux/version.h>
  #include <net/net_namespace.h>
  #include <net/netns/generic.h>
  
  #include "flow.h"
  #include "openvswitch/tunnel.h"
  #include "vport.h"
  
  /*
   * The absolute minimum fragment size.  Note that there are many other
   * definitions of the minimum MTU.
   */
  #define IP_MIN_MTU 68
  
  /*
   * One of these goes in struct tnl_ops and in tnl_find_port().
   * These values are in the same namespace as other TNL_T_* values, so
   * only the least significant 10 bits are available to define protocol
   * identifiers.
   */
  #define TNL_T_PROTO_GRE		0
  #define TNL_T_PROTO_GRE64	1
  #define TNL_T_PROTO_CAPWAP	2
  #define TNL_T_PROTO_VXLAN	3
  
  /* These flags are only needed when calling tnl_find_port(). */
  #define TNL_T_KEY_EXACT		(1 << 10)
  #define TNL_T_KEY_MATCH		(1 << 11)
  
  /* Private flags not exposed to userspace in this form. */
  #define TNL_F_IN_KEY_MATCH	(1 << 16) /* Store the key in tun_id to
  					   * match in flow table. */
  #define TNL_F_OUT_KEY_ACTION	(1 << 17) /* Get the key from a SET_TUNNEL
  					   * action. */
  
  /* All public tunnel flags. */
  #define TNL_F_PUBLIC (TNL_F_CSUM | TNL_F_TOS_INHERIT | TNL_F_TTL_INHERIT | \
  		      TNL_F_DF_INHERIT | TNL_F_DF_DEFAULT | TNL_F_PMTUD | \
  		      TNL_F_IPSEC)
  
  /**
   * struct port_lookup_key - Tunnel port key, used as hash table key.
   * @in_key: Key to match on input, 0 for wildcard.
   * @net: Network namespace of the port.
   * @saddr: IPv4 source address to match, 0 to accept any source address.
   * @daddr: IPv4 destination of tunnel.
   * @tunnel_type: Set of TNL_T_* flags that define lookup.
   */
  struct port_lookup_key {
  	__be64 in_key;
  #ifdef CONFIG_NET_NS
  	struct net *net;
  #endif
  	__be32 saddr;
  	__be32 daddr;
  	u32    tunnel_type;
  };
  
  #define PORT_KEY_LEN	(offsetof(struct port_lookup_key, tunnel_type) + \
  			 FIELD_SIZEOF(struct port_lookup_key, tunnel_type))
  
  static inline struct net *port_key_get_net(const struct port_lookup_key *key)
  {
  	return read_pnet(&key->net);
  }
  
  static inline void port_key_set_net(struct port_lookup_key *key, struct net *net)
  {
  	write_pnet(&key->net, net);
  }
  
  /**
   * struct tnl_mutable_config - modifiable configuration for a tunnel.
   * @key: Used as key for tunnel port.  Configured via OVS_TUNNEL_ATTR_*
   * attributes.
   * @rcu: RCU callback head for deferred destruction.
   * @seq: Sequence number for distinguishing configuration versions.
   * @tunnel_hlen: Tunnel header length.
   * @eth_addr: Source address for packets generated by tunnel itself
   * (e.g. ICMP fragmentation needed messages).
   * @out_key: Key to use on output, 0 if this tunnel has no fixed output key.
   * @flags: TNL_F_* flags.
   * @tos: IPv4 TOS value to use for tunnel, 0 if no fixed TOS.
   * @ttl: IPv4 TTL value to use for tunnel, 0 if no fixed TTL.
   */
  struct tnl_mutable_config {
  	struct port_lookup_key key;
  	struct rcu_head rcu;
  
  	unsigned seq;
  
  	unsigned char eth_addr[ETH_ALEN];
  
  	/* Configured via OVS_TUNNEL_ATTR_* attributes. */
  	__be64	out_key;
  	u32	flags;
  	u8	tos;
  	u8	ttl;
  	__be16	dst_port;
  
  	/* Multicast configuration. */
  	int	mlink;
  };
  
  struct tnl_ops {
  	u32 tunnel_type;	/* Put the TNL_T_PROTO_* type in here. */
  	u8 ipproto;		/* The IP protocol for the tunnel. */
  
  	/*
  	 * Returns the length of the tunnel header that will be added in
  	 * build_header() (i.e. excludes the IP header).  Returns a negative
  	 * error code if the configuration is invalid.
  	 */
  	int (*hdr_len)(const struct tnl_mutable_config *,
  		       const struct ovs_key_ipv4_tunnel *);
  	/*
  	 * Returns a linked list of SKBs with tunnel headers (multiple
  	 * packets may be generated in the event of fragmentation).  Space
  	 * will have already been allocated at the start of the packet equal
  	 * to sizeof(struct iphdr) + value returned by hdr_len().  The IP
  	 * header will have already been constructed.
  	 */
  	struct sk_buff *(*build_header)(const struct vport *,
  					 const struct tnl_mutable_config *,
  					 struct dst_entry *, struct sk_buff *,
  					 int tunnel_hlen);
  };
  
  struct tnl_vport {
  	struct rcu_head rcu;
  	struct hlist_node hash_node;
  
  	char name[IFNAMSIZ];
  	const struct tnl_ops *tnl_ops;
  
  	struct tnl_mutable_config __rcu *mutable;
  
  	/*
  	 * ID of last fragment sent (for tunnel protocols with direct support
  	 * fragmentation).  If the protocol relies on IP fragmentation then
  	 * this is not needed.
  	 */
  	atomic_t frag_id;
  };
  
  struct vport *ovs_tnl_create(const struct vport_parms *, const struct vport_ops *,
  			     const struct tnl_ops *);
  void ovs_tnl_destroy(struct vport *);
  
  int ovs_tnl_set_options(struct vport *, struct nlattr *);
  int ovs_tnl_get_options(const struct vport *, struct sk_buff *);
  
  int ovs_tnl_set_addr(struct vport *vport, const unsigned char *addr);
  const char *ovs_tnl_get_name(const struct vport *vport);
  const unsigned char *ovs_tnl_get_addr(const struct vport *vport);
  int ovs_tnl_send(struct vport *vport, struct sk_buff *skb);
  void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb);
  
  struct vport *ovs_tnl_find_port(struct net *net, __be32 saddr, __be32 daddr,
  				__be64 key, int tunnel_type,
  				const struct tnl_mutable_config **mutable);
  bool ovs_tnl_frag_needed(struct vport *vport,
  			 const struct tnl_mutable_config *mutable,
  			 struct sk_buff *skb, unsigned int mtu);
  void ovs_tnl_free_linked_skbs(struct sk_buff *skb);
  
  int ovs_tnl_init(void);
  void ovs_tnl_exit(void);
  static inline struct tnl_vport *tnl_vport_priv(const struct vport *vport)
  {
  	return vport_priv(vport);
  }
  
  static inline void tnl_tun_key_init(struct ovs_key_ipv4_tunnel *tun_key,
  				    const struct iphdr *iph, __be64 tun_id, u32 tun_flags)
  {
  	tun_key->tun_id = tun_id;
  	tun_key->ipv4_src = iph->saddr;
  	tun_key->ipv4_dst = iph->daddr;
  	tun_key->ipv4_tos = iph->tos;
  	tun_key->ipv4_ttl = iph->ttl;
  	tun_key->tun_flags = tun_flags;
  }
  
  static inline void tnl_get_param(const struct tnl_mutable_config *mutable,
  				 const struct ovs_key_ipv4_tunnel *tun_key,
  				 u32 *flags,  __be64 *out_key)
  {
  	if (tun_key->ipv4_dst) {
  		*flags = 0;
  
  		if (tun_key->tun_flags & OVS_TNL_F_KEY)
  			*flags = TNL_F_OUT_KEY_ACTION;
  		if (tun_key->tun_flags & OVS_TNL_F_CSUM)
  			*flags |= TNL_F_CSUM;
  		*out_key = tun_key->tun_id;
  	} else {
  		*flags = mutable->flags;
  		if (mutable->flags & TNL_F_OUT_KEY_ACTION)
  			*out_key = tun_key->tun_id;
  		else
  			*out_key = mutable->out_key;
  	}
  }
  
  #endif /* tunnel.h */
  