X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=datapath%2Ftunnel.h;h=8ffb7bf544446f9b108b683f1ba3aa154ff693d9;hb=842cf6f472b236b6e61be04b41970116245b1759;hp=37874c57cf3d6cc9e6718a806c756573526dd339;hpb=7c79397fe8ff52eb9cfe4d32a9d1f8b2f23c45c8;p=sliver-openvswitch.git diff --git a/datapath/tunnel.h b/datapath/tunnel.h index 37874c57c..8ffb7bf54 100644 --- a/datapath/tunnel.h +++ b/datapath/tunnel.h @@ -9,6 +9,9 @@ #ifndef TUNNEL_H #define TUNNEL_H 1 +#include + +#include "flow.h" #include "openvswitch/tunnel.h" #include "table.h" #include "vport.h" @@ -20,14 +23,15 @@ #define IP_MIN_MTU 68 /* - * One of these goes in your struct tnl_ops and in tnl_find_port(). + * 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 - * you have only the first 10 bits to define protocol identifiers. + * only the least significant 10 bits are available to define protocol + * identifiers. */ #define TNL_T_PROTO_GRE 0 #define TNL_T_PROTO_CAPWAP 1 -/* You only need these flags when you are calling tnl_find_port(). */ +/* These flags are only needed when calling tnl_find_port(). */ #define TNL_T_KEY_EXACT (1 << 10) #define TNL_T_KEY_MATCH (1 << 11) #define TNL_T_KEY_EITHER (TNL_T_KEY_EXACT | TNL_T_KEY_MATCH) @@ -35,39 +39,119 @@ struct tnl_mutable_config { struct rcu_head rcu; - unsigned char eth_addr[ETH_ALEN]; - unsigned int mtu; - struct tnl_port_config port_config; + unsigned seq; /* Sequence number to identify this config. */ - /* Set of TNL_T_* flags that define the category for lookup. */ - u32 tunnel_type; + u32 tunnel_type; /* Set of TNL_T_* flags that define lookup. */ + unsigned tunnel_hlen; /* Tunnel header length. */ + + unsigned char eth_addr[ETH_ALEN]; + unsigned mtu; - int tunnel_hlen; /* Tunnel header length. */ + struct tnl_port_config port_config; }; struct tnl_ops { - /* Put your TNL_T_PROTO_* type in here. */ - u32 tunnel_type; - u8 ipproto; + 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 you will add in + * 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_port_config *); /* - * 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. + * Builds the static portion of the tunnel header, which is stored in + * the header cache. In general the performance of this function is + * not too important as we try to only call it when building the cache + * so it is preferable to shift as much work as possible here. However, + * in some circumstances caching is disabled and this function will be + * called for every packet, so try not to make it too slow. + */ + void (*build_header)(const struct vport *, + const struct tnl_mutable_config *, void *header); + + /* + * Updates the cached header of a packet to match the actual packet + * data. Typical things that might need to be updated are length, + * checksum, etc. The IP header will have already been updated and this + * is the final step before transmission. Returns a linked list of + * completed SKBs (multiple packets may be generated in the event + * of fragmentation). + */ + struct sk_buff *(*update_header)(const struct vport *, + const struct tnl_mutable_config *, + struct dst_entry *, struct sk_buff *); +}; + +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20) +/* + * On these kernels we have a fast mechanism to tell if the ARP cache for a + * particular destination has changed. + */ +#define HAVE_HH_SEQ +#endif +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27) +/* + * On these kernels we have a fast mechanism to tell if the routing table + * has changed. + */ +#define HAVE_RT_GENID +#endif +#if !defined(HAVE_HH_SEQ) || !defined(HAVE_RT_GENID) +/* If we can't detect all system changes directly we need to use a timeout. */ +#define NEED_CACHE_TIMEOUT +#endif +struct tnl_cache { + struct rcu_head rcu; + + int len; /* Length of data to be memcpy'd from cache. */ + + /* Sequence number of mutable->seq from which this cache was generated. */ + unsigned mutable_seq; + +#ifdef HAVE_HH_SEQ + /* + * The sequence number from the seqlock protecting the hardware header + * cache (in the ARP cache). Since every write increments the counter + * this gives us an easy way to tell if it has changed. + */ + unsigned hh_seq; +#endif + +#ifdef NEED_CACHE_TIMEOUT + /* + * If we don't have direct mechanisms to detect all important changes in + * the system fall back to an expiration time. This expiration time + * can be relatively short since at high rates there will be millions of + * packets per second, so we'll still get plenty of benefit from the + * cache. Note that if something changes we may blackhole packets + * until the expiration time (depending on what changed and the kernel + * version we may be able to detect the change sooner). Expiration is + * expressed as a time in jiffies. */ - struct sk_buff *(*build_header)(struct sk_buff *, - const struct vport *, - const struct tnl_mutable_config *, - struct dst_entry *); + unsigned long expiration; +#endif + + /* + * The routing table entry that is the result of looking up the tunnel + * endpoints. It also contains a sequence number (called a generation + * ID) that can be compared to a global sequence to tell if the routing + * table has changed (and therefore there is a potential that this + * cached route has been invalidated). + */ + struct rtable *rt; + + /* + * If the output device for tunnel traffic is an OVS internal device, + * the flow of that datapath. Since all tunnel traffic will have the + * same headers this allows us to cache the flow lookup. NULL if the + * output device is not OVS or if there is no flow installed. + */ + struct sw_flow *flow; + + /* The cached header follows after padding for alignment. */ }; struct tnl_vport { @@ -77,14 +161,29 @@ struct tnl_vport { char name[IFNAMSIZ]; const struct tnl_ops *tnl_ops; - /* Protected by RCU. */ - struct tnl_mutable_config *mutable; + struct tnl_mutable_config *mutable; /* Protected by RCU. */ + /* + * 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; + + spinlock_t cache_lock; + struct tnl_cache *cache; /* Protected by RCU/cache_lock. */ + +#ifdef NEED_CACHE_TIMEOUT + /* + * If we must rely on expiration time to invalidate the cache, this is + * the interval. It is randomized within a range (defined by + * MAX_CACHE_EXP in tunnel.c) to avoid synchronized expirations caused + * by creation of a large number of tunnels at a one time. + */ + unsigned long cache_exp_interval; +#endif }; -int tnl_init(void); -void tnl_exit(void); struct vport *tnl_create(const char *name, const void __user *config, const struct vport_ops *, const struct tnl_ops *); @@ -104,10 +203,12 @@ struct vport *tnl_find_port(__be32 saddr, __be32 daddr, __be32 key, bool tnl_frag_needed(struct vport *vport, const struct tnl_mutable_config *mutable, struct sk_buff *skb, unsigned int mtu, __be32 flow_key); +void tnl_free_linked_skbs(struct sk_buff *skb); static inline struct tnl_vport *tnl_vport_priv(const struct vport *vport) { return vport_priv(vport); } + #endif /* tunnel.h */