2 * Copyright (c) 2007-2011 Nicira Networks.
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.
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.
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
22 #include <linux/version.h>
25 #include "openvswitch/tunnel.h"
29 * The absolute minimum fragment size. Note that there are many other
30 * definitions of the minimum MTU.
35 * One of these goes in struct tnl_ops and in tnl_find_port().
36 * These values are in the same namespace as other TNL_T_* values, so
37 * only the least significant 10 bits are available to define protocol
40 #define TNL_T_PROTO_GRE 0
41 #define TNL_T_PROTO_CAPWAP 1
43 /* These flags are only needed when calling tnl_find_port(). */
44 #define TNL_T_KEY_EXACT (1 << 10)
45 #define TNL_T_KEY_MATCH (1 << 11)
47 /* Private flags not exposed to userspace in this form. */
48 #define TNL_F_IN_KEY_MATCH (1 << 16) /* Store the key in tun_id to
49 * match in flow table. */
50 #define TNL_F_OUT_KEY_ACTION (1 << 17) /* Get the key from a SET_TUNNEL
53 /* All public tunnel flags. */
54 #define TNL_F_PUBLIC (TNL_F_CSUM | TNL_F_TOS_INHERIT | TNL_F_TTL_INHERIT | \
55 TNL_F_DF_INHERIT | TNL_F_DF_DEFAULT | TNL_F_PMTUD | \
56 TNL_F_HDR_CACHE | TNL_F_IPSEC)
59 * struct port_lookup_key - Tunnel port key, used as hash table key.
60 * @in_key: Key to match on input, 0 for wildcard.
61 * @saddr: IPv4 source address to match, 0 to accept any source address.
62 * @daddr: IPv4 destination of tunnel.
63 * @tunnel_type: Set of TNL_T_* flags that define lookup.
65 struct port_lookup_key {
72 #define PORT_KEY_LEN (offsetof(struct port_lookup_key, tunnel_type) + \
73 FIELD_SIZEOF(struct port_lookup_key, tunnel_type))
76 * struct tnl_mutable_config - modifiable configuration for a tunnel.
77 * @key: Used as key for tunnel port. Configured via OVS_TUNNEL_ATTR_*
79 * @rcu: RCU callback head for deferred destruction.
80 * @seq: Sequence number for distinguishing configuration versions.
81 * @tunnel_hlen: Tunnel header length.
82 * @eth_addr: Source address for packets generated by tunnel itself
83 * (e.g. ICMP fragmentation needed messages).
84 * @out_key: Key to use on output, 0 if this tunnel has no fixed output key.
85 * @flags: TNL_F_* flags.
86 * @tos: IPv4 TOS value to use for tunnel, 0 if no fixed TOS.
87 * @ttl: IPv4 TTL value to use for tunnel, 0 if no fixed TTL.
89 struct tnl_mutable_config {
90 struct port_lookup_key key;
97 unsigned char eth_addr[ETH_ALEN];
99 /* Configured via OVS_TUNNEL_ATTR_* attributes. */
105 /* Multicast configuration. */
110 u32 tunnel_type; /* Put the TNL_T_PROTO_* type in here. */
111 u8 ipproto; /* The IP protocol for the tunnel. */
114 * Returns the length of the tunnel header that will be added in
115 * build_header() (i.e. excludes the IP header). Returns a negative
116 * error code if the configuration is invalid.
118 int (*hdr_len)(const struct tnl_mutable_config *);
121 * Builds the static portion of the tunnel header, which is stored in
122 * the header cache. In general the performance of this function is
123 * not too important as we try to only call it when building the cache
124 * so it is preferable to shift as much work as possible here. However,
125 * in some circumstances caching is disabled and this function will be
126 * called for every packet, so try not to make it too slow.
128 void (*build_header)(const struct vport *,
129 const struct tnl_mutable_config *, void *header);
132 * Updates the cached header of a packet to match the actual packet
133 * data. Typical things that might need to be updated are length,
134 * checksum, etc. The IP header will have already been updated and this
135 * is the final step before transmission. Returns a linked list of
136 * completed SKBs (multiple packets may be generated in the event
139 struct sk_buff *(*update_header)(const struct vport *,
140 const struct tnl_mutable_config *,
141 struct dst_entry *, struct sk_buff *);
144 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
146 * On these kernels we have a fast mechanism to tell if the ARP cache for a
147 * particular destination has changed.
151 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
153 * On these kernels we have a fast mechanism to tell if the routing table
156 #define HAVE_RT_GENID
158 #if !defined(HAVE_HH_SEQ) || !defined(HAVE_RT_GENID)
159 /* If we can't detect all system changes directly we need to use a timeout. */
160 #define NEED_CACHE_TIMEOUT
165 int len; /* Length of data to be memcpy'd from cache. */
166 int hh_len; /* Hardware hdr length, cached from hh_cache. */
168 /* Sequence number of mutable->seq from which this cache was
170 unsigned mutable_seq;
174 * The sequence number from the seqlock protecting the hardware header
175 * cache (in the ARP cache). Since every write increments the counter
176 * this gives us an easy way to tell if it has changed.
181 #ifdef NEED_CACHE_TIMEOUT
183 * If we don't have direct mechanisms to detect all important changes in
184 * the system fall back to an expiration time. This expiration time
185 * can be relatively short since at high rates there will be millions of
186 * packets per second, so we'll still get plenty of benefit from the
187 * cache. Note that if something changes we may blackhole packets
188 * until the expiration time (depending on what changed and the kernel
189 * version we may be able to detect the change sooner). Expiration is
190 * expressed as a time in jiffies.
192 unsigned long expiration;
196 * The routing table entry that is the result of looking up the tunnel
197 * endpoints. It also contains a sequence number (called a generation
198 * ID) that can be compared to a global sequence to tell if the routing
199 * table has changed (and therefore there is a potential that this
200 * cached route has been invalidated).
205 * If the output device for tunnel traffic is an OVS internal device,
206 * the flow of that datapath. Since all tunnel traffic will have the
207 * same headers this allows us to cache the flow lookup. NULL if the
208 * output device is not OVS or if there is no flow installed.
210 struct sw_flow *flow;
212 /* The cached header follows after padding for alignment. */
217 struct hlist_node hash_node;
220 const struct tnl_ops *tnl_ops;
222 struct tnl_mutable_config __rcu *mutable;
225 * ID of last fragment sent (for tunnel protocols with direct support
226 * fragmentation). If the protocol relies on IP fragmentation then
227 * this is not needed.
231 spinlock_t cache_lock;
232 struct tnl_cache __rcu *cache; /* Protected by RCU/cache_lock. */
234 #ifdef NEED_CACHE_TIMEOUT
236 * If we must rely on expiration time to invalidate the cache, this is
237 * the interval. It is randomized within a range (defined by
238 * MAX_CACHE_EXP in tunnel.c) to avoid synchronized expirations caused
239 * by creation of a large number of tunnels at a one time.
241 unsigned long cache_exp_interval;
245 struct vport *ovs_tnl_create(const struct vport_parms *, const struct vport_ops *,
246 const struct tnl_ops *);
247 void ovs_tnl_destroy(struct vport *);
249 int ovs_tnl_set_options(struct vport *, struct nlattr *);
250 int ovs_tnl_get_options(const struct vport *, struct sk_buff *);
252 int ovs_tnl_set_addr(struct vport *vport, const unsigned char *addr);
253 const char *ovs_tnl_get_name(const struct vport *vport);
254 const unsigned char *ovs_tnl_get_addr(const struct vport *vport);
255 int ovs_tnl_send(struct vport *vport, struct sk_buff *skb);
256 void ovs_tnl_rcv(struct vport *vport, struct sk_buff *skb, u8 tos);
258 struct vport *ovs_tnl_find_port(__be32 saddr, __be32 daddr, __be64 key,
260 const struct tnl_mutable_config **mutable);
261 bool ovs_tnl_frag_needed(struct vport *vport,
262 const struct tnl_mutable_config *mutable,
263 struct sk_buff *skb, unsigned int mtu, __be64 flow_key);
264 void ovs_tnl_free_linked_skbs(struct sk_buff *skb);
266 int ovs_tnl_init(void);
267 void ovs_tnl_exit(void);
268 static inline struct tnl_vport *tnl_vport_priv(const struct vport *vport)
270 return vport_priv(vport);
273 #endif /* tunnel.h */