net/openvswitch/datapath.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 DATAPATH_H
  20 #define DATAPATH_H 1
  21
  22 #include <asm/page.h>
  23 #include <linux/kernel.h>
  24 #include <linux/mutex.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/skbuff.h>
  27 #include <linux/u64_stats_sync.h>
  28
  29 #include "flow.h"
  30 #include "vport.h"
  31
  32 #define DP_MAX_PORTS           USHRT_MAX
  33 #define DP_VPORT_HASH_BUCKETS  1024
  34
  35 #define SAMPLE_ACTION_DEPTH 3
  36
  37 /**
  38  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  39  * datapath.
  40  * @n_hit: Number of received packets for which a matching flow was found in
  41  * the flow table.
  42  * @n_miss: Number of received packets that had no matching flow in the flow
  43  * table.  The sum of @n_hit and @n_miss is the number of packets that have
  44  * been received by the datapath.
  45  * @n_lost: Number of received packets that had no matching flow in the flow
  46  * table that could not be sent to userspace (normally due to an overflow in
  47  * one of the datapath's queues).
  48  */
  49 struct dp_stats_percpu {
  50         u64 n_hit;
  51         u64 n_missed;
  52         u64 n_lost;
  53         struct u64_stats_sync sync;
  54 };
  55
  56 /**
  57  * struct datapath - datapath for flow-based packet switching
  58  * @rcu: RCU callback head for deferred destruction.
  59  * @list_node: Element in global 'dps' list.
  60  * @table: Current flow table.  Protected by ovs_mutex and RCU.
  61  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  62  * ovs_mutex and RCU.
  63  * @stats_percpu: Per-CPU datapath statistics.
  64  * @net: Reference to net namespace.
  65  *
  66  * Context: See the comment on locking at the top of datapath.c for additional
  67  * locking information.
  68  */
  69 struct datapath {
  70         struct rcu_head rcu;
  71         struct list_head list_node;
  72
  73         /* Flow table. */
  74         struct flow_table __rcu *table;
  75
  76         /* Switch ports. */
  77         struct hlist_head *ports;
  78
  79         /* Stats. */
  80         struct dp_stats_percpu __percpu *stats_percpu;
  81
  82 #ifdef CONFIG_NET_NS
  83         /* Network namespace ref. */
  84         struct net *net;
  85 #endif
  86 };
  87
  88 /**
  89  * struct ovs_skb_cb - OVS data in skb CB
  90  * @flow: The flow associated with this packet.  May be %NULL if no flow.
  91  * @pkt_key: The flow information extracted from the packet.  Must be nonnull.
  92  * @tun_key: Key for the tunnel that encapsulated this packet. NULL if the
  93  * packet is not being tunneled.
  94  */
  95 struct ovs_skb_cb {
  96         struct sw_flow          *flow;
  97         struct sw_flow_key      *pkt_key;
  98         struct ovs_key_ipv4_tunnel  *tun_key;
  99 };
 100 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 101
 102 /**
 103  * struct dp_upcall - metadata to include with a packet to send to userspace
 104  * @cmd: One of %OVS_PACKET_CMD_*.
 105  * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
 106  * @userdata: If nonnull, its variable-length value is passed to userspace as
 107  * %OVS_PACKET_ATTR_USERDATA.
 108  * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
 109  * packet is sent and the packet is accounted in the datapath's @n_lost
 110  * counter.
 111  */
 112 struct dp_upcall_info {
 113         u8 cmd;
 114         const struct sw_flow_key *key;
 115         const struct nlattr *userdata;
 116         u32 portid;
 117 };
 118
 119 /**
 120  * struct ovs_net - Per net-namespace data for ovs.
 121  * @dps: List of datapaths to enable dumping them all out.
 122  * Protected by genl_mutex.
 123  */
 124 struct ovs_net {
 125         struct list_head dps;
 126         struct work_struct dp_notify_work;
 127         struct vport_net vport_net;
 128 };
 129
 130 extern int ovs_net_id;
 131 void ovs_lock(void);
 132 void ovs_unlock(void);
 133
 134 #ifdef CONFIG_LOCKDEP
 135 int lockdep_ovsl_is_held(void);
 136 #else
 137 #define lockdep_ovsl_is_held()  1
 138 #endif
 139
 140 #define ASSERT_OVSL()           WARN_ON(unlikely(!lockdep_ovsl_is_held()))
 141 #define ovsl_dereference(p)                                     \
 142         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 143
 144 static inline struct net *ovs_dp_get_net(struct datapath *dp)
 145 {
 146         return read_pnet(&dp->net);
 147 }
 148
 149 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 150 {
 151         write_pnet(&dp->net, net);
 152 }
 153
 154 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 155
 156 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 157 {
 158         WARN_ON_ONCE(!rcu_read_lock_held());
 159         return ovs_lookup_vport(dp, port_no);
 160 }
 161
 162 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 163 {
 164         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 165         return ovs_lookup_vport(dp, port_no);
 166 }
 167
 168 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 169 {
 170         ASSERT_OVSL();
 171         return ovs_lookup_vport(dp, port_no);
 172 }
 173
 174 extern struct notifier_block ovs_dp_device_notifier;
 175 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
 176
 177 void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
 178 void ovs_dp_detach_port(struct vport *);
 179 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 180                   const struct dp_upcall_info *);
 181
 182 const char *ovs_dp_name(const struct datapath *dp);
 183 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 184                                          u8 cmd);
 185
 186 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb);
 187 void ovs_dp_notify_wq(struct work_struct *work);
 188
 189 #define OVS_NLERR(fmt, ...) \
 190         pr_info_once("netlink: " fmt, ##__VA_ARGS__)
 191
 192 #endif /* datapath.h */