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 #define TNL_T_PROTO_VXLAN       3
  46
  47 /* These flags are only needed when calling tnl_find_port(). */
  48 #define TNL_T_KEY_EXACT         (1 << 10)
  49 #define TNL_T_KEY_MATCH         (1 << 11)
  50
  51 /* Private flags not exposed to userspace in this form. */
  52 #define TNL_F_IN_KEY_MATCH      (1 << 16) /* Store the key in tun_id to
  53                                            * match in flow table. */
  54 #define TNL_F_OUT_KEY_ACTION    (1 << 17) /* Get the key from a SET_TUNNEL
  55                                            * action. */
  56
  57 /* All public tunnel flags. */
  58 #define TNL_F_PUBLIC (TNL_F_CSUM | TNL_F_TOS_INHERIT | TNL_F_TTL_INHERIT | \
  59                       TNL_F_DF_INHERIT | TNL_F_DF_DEFAULT | TNL_F_PMTUD | \
  60                       TNL_F_IPSEC)
  61
  62 /**
  63  * struct port_lookup_key - Tunnel port key, used as hash table key.
  64  * @in_key: Key to match on input, 0 for wildcard.
  65  * @net: Network namespace of the port.
  66  * @saddr: IPv4 source address to match, 0 to accept any source address.
  67  * @daddr: IPv4 destination of tunnel.
  68  * @tunnel_type: Set of TNL_T_* flags that define lookup.
  69  */
  70 struct port_lookup_key {
  71         __be64 in_key;
  72 #ifdef CONFIG_NET_NS
  73         struct net *net;
  74 #endif
  75         __be32 saddr;
  76         __be32 daddr;
  77         u32    tunnel_type;
  78 };
  79
  80 #define PORT_KEY_LEN    (offsetof(struct port_lookup_key, tunnel_type) + \
  81                          FIELD_SIZEOF(struct port_lookup_key, tunnel_type))
  82
  83 static inline struct net *port_key_get_net(const struct port_lookup_key *key)
  84 {
  85         return read_pnet(&key->net);
  86 }
  87
  88 static inline void port_key_set_net(struct port_lookup_key *key, struct net *net)
  89 {
  90         write_pnet(&key->net, net);
  91 }
  92
  93 /**
  94  * struct tnl_mutable_config - modifiable configuration for a tunnel.
  95  * @key: Used as key for tunnel port.  Configured via OVS_TUNNEL_ATTR_*
  96  * attributes.
  97  * @rcu: RCU callback head for deferred destruction.
  98  * @seq: Sequence number for distinguishing configuration versions.
  99  * @tunnel_hlen: Tunnel header length.
 100  * @eth_addr: Source address for packets generated by tunnel itself
 101  * (e.g. ICMP fragmentation needed messages).
 102  * @out_key: Key to use on output, 0 if this tunnel has no fixed output key.
 103  * @flags: TNL_F_* flags.
 104  * @tos: IPv4 TOS value to use for tunnel, 0 if no fixed TOS.
 105  * @ttl: IPv4 TTL value to use for tunnel, 0 if no fixed TTL.
 106  */
 107 struct tnl_mutable_config {
 108         struct port_lookup_key key;
 109         struct rcu_head rcu;
 110
 111         unsigned seq;
 112
 113         unsigned char eth_addr[ETH_ALEN];
 114
 115         /* Configured via OVS_TUNNEL_ATTR_* attributes. */
 116         __be64  out_key;
 117         u32     flags;
 118         u8      tos;
 119         u8      ttl;
 120         __be16  dst_port;
 121
 122         /* Multicast configuration. */
 123         int     mlink;
 124 };
 125
 126 struct tnl_ops {
 127         u32 tunnel_type;        /* Put the TNL_T_PROTO_* type in here. */
 128         u8 ipproto;             /* The IP protocol for the tunnel. */
 129
 130         /*
 131          * Returns the length of the tunnel header that will be added in
 132          * build_header() (i.e. excludes the IP header).  Returns a negative
 133          * error code if the configuration is invalid.
 134          */
 135         int (*hdr_len)(const struct tnl_mutable_config *,
 136                        const struct ovs_key_ipv4_tunnel *);
 137         /*
 138          * Returns a linked list of SKBs with tunnel headers (multiple
 139          * packets may be generated in the event of fragmentation).  Space
 140          * will have already been allocated at the start of the packet equal
 141          * to sizeof(struct iphdr) + value returned by hdr_len().  The IP
 142          * header will have already been constructed.
 143          */
 144         struct sk_buff *(*build_header)(const struct vport *,
 145                                          const struct tnl_mutable_config *,
 146                                          struct dst_entry *, struct sk_buff *,
 147                                          int tunnel_hlen);
 148 };
 149
 150 struct tnl_vport {
 151         struct rcu_head rcu;
 152         struct hlist_node hash_node;
 153
 154         char name[IFNAMSIZ];
 155         const struct tnl_ops *tnl_ops;
 156
 157         struct tnl_mutable_config __rcu *mutable;
 158
 159         /*
 160          * ID of last fragment sent (for tunnel protocols with direct support
 161          * fragmentation).  If the protocol relies on IP fragmentation then
 162          * this is not needed.
 163          */
 164         atomic_t frag_id;
 165 };
 166
 167 struct vport *ovs_tnl_create(const struct vport_parms *, const struct vport_ops *,
 168                              const struct tnl_ops *);
 169 void ovs_tnl_destroy(struct vport *);
 170
 171 int ovs_tnl_set_options(struct vport *, struct nlattr *);
 172 int ovs_tnl_get_options(const struct vport *, struct sk_buff *);
 173
 174 int ovs_tnl_set_addr(struct vport *vport, const unsigned char *addr);
 175 const char *ovs_tnl_get_name(const struct vport *vport);
 176 const unsigned char *ovs_tnl_get_addr(const struct vport *vport);
 177 int ovs_tnl_send(struct vport *vport, struct sk_buff *skb);
 178 void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb);
 179
 180 struct vport *ovs_tnl_find_port(struct net *net, __be32 saddr, __be32 daddr,
 181                                 __be64 key, int tunnel_type,
 182                                 const struct tnl_mutable_config **mutable);
 183 bool ovs_tnl_frag_needed(struct vport *vport,
 184                          const struct tnl_mutable_config *mutable,
 185                          struct sk_buff *skb, unsigned int mtu);
 186 void ovs_tnl_free_linked_skbs(struct sk_buff *skb);
 187
 188 int ovs_tnl_init(void);
 189 void ovs_tnl_exit(void);
 190 static inline struct tnl_vport *tnl_vport_priv(const struct vport *vport)
 191 {
 192         return vport_priv(vport);
 193 }
 194
 195 static inline void tnl_tun_key_init(struct ovs_key_ipv4_tunnel *tun_key,
 196                                     const struct iphdr *iph, __be64 tun_id, u32 tun_flags)
 197 {
 198         tun_key->tun_id = tun_id;
 199         tun_key->ipv4_src = iph->saddr;
 200         tun_key->ipv4_dst = iph->daddr;
 201         tun_key->ipv4_tos = iph->tos;
 202         tun_key->ipv4_ttl = iph->ttl;
 203         tun_key->tun_flags = tun_flags;
 204 }
 205
 206 static inline void tnl_get_param(const struct tnl_mutable_config *mutable,
 207                                  const struct ovs_key_ipv4_tunnel *tun_key,
 208                                  u32 *flags,  __be64 *out_key)
 209 {
 210         if (tun_key->ipv4_dst) {
 211                 *flags = 0;
 212
 213                 if (tun_key->tun_flags & OVS_TNL_F_KEY)
 214                         *flags = TNL_F_OUT_KEY_ACTION;
 215                 if (tun_key->tun_flags & OVS_TNL_F_CSUM)
 216                         *flags |= TNL_F_CSUM;
 217                 *out_key = tun_key->tun_id;
 218         } else {
 219                 *flags = mutable->flags;
 220                 if (mutable->flags & TNL_F_OUT_KEY_ACTION)
 221                         *out_key = tun_key->tun_id;
 222                 else
 223                         *out_key = mutable->out_key;
 224         }
 225 }
 226
 227 #endif /* tunnel.h */