datapath/tunnel.h

   1 /*
   2  * Copyright (c) 2007-2012 Nicira, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 2 of the GNU General Public
   6  * License as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write to the Free Software
  15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  16  * 02110-1301, USA
  17  */
  18
  19 #ifndef TUNNEL_H
  20 #define TUNNEL_H 1
  21
  22 #include <linux/version.h>
  23 #include <net/net_namespace.h>
  24 #include <net/netns/generic.h>
  25
  26 #include "flow.h"
  27 #include "openvswitch/tunnel.h"
  28 #include "vport.h"
  29
  30 /*
  31  * The absolute minimum fragment size.  Note that there are many other
  32  * definitions of the minimum MTU.
  33  */
  34 #define IP_MIN_MTU 68
  35
  36 /*
  37  * One of these goes in struct tnl_ops and in tnl_find_port().
  38  * These values are in the same namespace as other TNL_T_* values, so
  39  * only the least significant 10 bits are available to define protocol
  40  * identifiers.
  41  */
  42 #define TNL_T_PROTO_GRE         0
  43 #define TNL_T_PROTO_GRE64       1
  44 #define TNL_T_PROTO_CAPWAP      2
  45
  46 /* These flags are only needed when calling tnl_find_port(). */
  47 #define TNL_T_KEY_EXACT         (1 << 10)
  48 #define TNL_T_KEY_MATCH         (1 << 11)
  49
  50 /* Private flags not exposed to userspace in this form. */
  51 #define TNL_F_IN_KEY_MATCH      (1 << 16) /* Store the key in tun_id to
  52                                            * match in flow table. */
  53 #define TNL_F_OUT_KEY_ACTION    (1 << 17) /* Get the key from a SET_TUNNEL
  54                                            * action. */
  55
  56 /* All public tunnel flags. */
  57 #define TNL_F_PUBLIC (TNL_F_CSUM | TNL_F_TOS_INHERIT | TNL_F_TTL_INHERIT | \
  58                       TNL_F_DF_INHERIT | TNL_F_DF_DEFAULT | TNL_F_PMTUD | \
  59                       TNL_F_IPSEC)
  60
  61 /**
  62  * struct port_lookup_key - Tunnel port key, used as hash table key.
  63  * @in_key: Key to match on input, 0 for wildcard.
  64  * @net: Network namespace of the port.
  65  * @saddr: IPv4 source address to match, 0 to accept any source address.
  66  * @daddr: IPv4 destination of tunnel.
  67  * @tunnel_type: Set of TNL_T_* flags that define lookup.
  68  */
  69 struct port_lookup_key {
  70         __be64 in_key;
  71 #ifdef CONFIG_NET_NS
  72         struct net *net;
  73 #endif
  74         __be32 saddr;
  75         __be32 daddr;
  76         u32    tunnel_type;
  77 };
  78
  79 #define PORT_KEY_LEN    (offsetof(struct port_lookup_key, tunnel_type) + \
  80                          FIELD_SIZEOF(struct port_lookup_key, tunnel_type))
  81
  82 static inline struct net *port_key_get_net(const struct port_lookup_key *key)
  83 {
  84         return read_pnet(&key->net);
  85 }
  86
  87 static inline void port_key_set_net(struct port_lookup_key *key, struct net *net)
  88 {
  89         write_pnet(&key->net, net);
  90 }
  91
  92 /**
  93  * struct tnl_mutable_config - modifiable configuration for a tunnel.
  94  * @key: Used as key for tunnel port.  Configured via OVS_TUNNEL_ATTR_*
  95  * attributes.
  96  * @rcu: RCU callback head for deferred destruction.
  97  * @seq: Sequence number for distinguishing configuration versions.
  98  * @tunnel_hlen: Tunnel header length.
  99  * @eth_addr: Source address for packets generated by tunnel itself
 100  * (e.g. ICMP fragmentation needed messages).
 101  * @out_key: Key to use on output, 0 if this tunnel has no fixed output key.
 102  * @flags: TNL_F_* flags.
 103  * @tos: IPv4 TOS value to use for tunnel, 0 if no fixed TOS.
 104  * @ttl: IPv4 TTL value to use for tunnel, 0 if no fixed TTL.
 105  */
 106 struct tnl_mutable_config {
 107         struct port_lookup_key key;
 108         struct rcu_head rcu;
 109
 110         unsigned seq;
 111
 112         unsigned char eth_addr[ETH_ALEN];
 113
 114         /* Configured via OVS_TUNNEL_ATTR_* attributes. */
 115         __be64  out_key;
 116         u32     flags;
 117         u8      tos;
 118         u8      ttl;
 119
 120         /* Multicast configuration. */
 121         int     mlink;
 122 };
 123
 124 struct tnl_ops {
 125         u32 tunnel_type;        /* Put the TNL_T_PROTO_* type in here. */
 126         u8 ipproto;             /* The IP protocol for the tunnel. */
 127
 128         /*
 129          * Returns the length of the tunnel header that will be added in
 130          * build_header() (i.e. excludes the IP header).  Returns a negative
 131          * error code if the configuration is invalid.
 132          */
 133         int (*hdr_len)(const struct tnl_mutable_config *,
 134                        const struct ovs_key_ipv4_tunnel *);
 135         /*
 136          * Returns a linked list of SKBs with tunnel headers (multiple
 137          * packets may be generated in the event of fragmentation).  Space
 138          * will have already been allocated at the start of the packet equal
 139          * to sizeof(struct iphdr) + value returned by hdr_len().  The IP
 140          * header will have already been constructed.
 141          */
 142         struct sk_buff *(*build_header)(const struct vport *,
 143                                          const struct tnl_mutable_config *,
 144                                          struct dst_entry *, struct sk_buff *,
 145                                          int tunnel_hlen);
 146 };
 147
 148 struct tnl_vport {
 149         struct rcu_head rcu;
 150         struct hlist_node hash_node;
 151
 152         char name[IFNAMSIZ];
 153         const struct tnl_ops *tnl_ops;
 154
 155         struct tnl_mutable_config __rcu *mutable;
 156
 157         /*
 158          * ID of last fragment sent (for tunnel protocols with direct support
 159          * fragmentation).  If the protocol relies on IP fragmentation then
 160          * this is not needed.
 161          */
 162         atomic_t frag_id;
 163 };
 164
 165 struct vport *ovs_tnl_create(const struct vport_parms *, const struct vport_ops *,
 166                              const struct tnl_ops *);
 167 void ovs_tnl_destroy(struct vport *);
 168
 169 int ovs_tnl_set_options(struct vport *, struct nlattr *);
 170 int ovs_tnl_get_options(const struct vport *, struct sk_buff *);
 171
 172 int ovs_tnl_set_addr(struct vport *vport, const unsigned char *addr);
 173 const char *ovs_tnl_get_name(const struct vport *vport);
 174 const unsigned char *ovs_tnl_get_addr(const struct vport *vport);
 175 int ovs_tnl_send(struct vport *vport, struct sk_buff *skb);
 176 void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb);
 177
 178 struct vport *ovs_tnl_find_port(struct net *net, __be32 saddr, __be32 daddr,
 179                                 __be64 key, int tunnel_type,
 180                                 const struct tnl_mutable_config **mutable);
 181 bool ovs_tnl_frag_needed(struct vport *vport,
 182                          const struct tnl_mutable_config *mutable,
 183                          struct sk_buff *skb, unsigned int mtu);
 184 void ovs_tnl_free_linked_skbs(struct sk_buff *skb);
 185
 186 int ovs_tnl_init(void);
 187 void ovs_tnl_exit(void);
 188 static inline struct tnl_vport *tnl_vport_priv(const struct vport *vport)
 189 {
 190         return vport_priv(vport);
 191 }
 192
 193 static inline void tnl_tun_key_init(struct ovs_key_ipv4_tunnel *tun_key,
 194                                     const struct iphdr *iph, __be64 tun_id, u32 tun_flags)
 195 {
 196         tun_key->tun_id = tun_id;
 197         tun_key->ipv4_src = iph->saddr;
 198         tun_key->ipv4_dst = iph->daddr;
 199         tun_key->ipv4_tos = iph->tos;
 200         tun_key->ipv4_ttl = iph->ttl;
 201         tun_key->tun_flags = tun_flags;
 202 }
 203
 204 #endif /* tunnel.h */