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  * @tun_key: Key for the tunnel that encapsulated this packet. NULL if the
  92  * packet is not being tunneled.
  93  */
  94 struct ovs_skb_cb {
  95         struct sw_flow          *flow;
  96         struct ovs_key_ipv4_tunnel  *tun_key;
  97 };
  98 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
  99
 100 /**
 101  * struct dp_upcall - metadata to include with a packet to send to userspace
 102  * @cmd: One of %OVS_PACKET_CMD_*.
 103  * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
 104  * @userdata: If nonnull, its variable-length value is passed to userspace as
 105  * %OVS_PACKET_ATTR_USERDATA.
 106  * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
 107  * packet is sent and the packet is accounted in the datapath's @n_lost
 108  * counter.
 109  */
 110 struct dp_upcall_info {
 111         u8 cmd;
 112         const struct sw_flow_key *key;
 113         const struct nlattr *userdata;
 114         u32 portid;
 115 };
 116
 117 /**
 118  * struct ovs_net - Per net-namespace data for ovs.
 119  * @dps: List of datapaths to enable dumping them all out.
 120  * Protected by genl_mutex.
 121  */
 122 struct ovs_net {
 123         struct list_head dps;
 124         struct work_struct dp_notify_work;
 125         struct vport_net vport_net;
 126 };
 127
 128 extern int ovs_net_id;
 129 void ovs_lock(void);
 130 void ovs_unlock(void);
 131
 132 #ifdef CONFIG_LOCKDEP
 133 int lockdep_ovsl_is_held(void);
 134 #else
 135 #define lockdep_ovsl_is_held()  1
 136 #endif
 137
 138 #define ASSERT_OVSL()           WARN_ON(unlikely(!lockdep_ovsl_is_held()))
 139 #define ovsl_dereference(p)                                     \
 140         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 141
 142 static inline struct net *ovs_dp_get_net(struct datapath *dp)
 143 {
 144         return read_pnet(&dp->net);
 145 }
 146
 147 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 148 {
 149         write_pnet(&dp->net, net);
 150 }
 151
 152 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 153
 154 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 155 {
 156         WARN_ON_ONCE(!rcu_read_lock_held());
 157         return ovs_lookup_vport(dp, port_no);
 158 }
 159
 160 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 161 {
 162         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 163         return ovs_lookup_vport(dp, port_no);
 164 }
 165
 166 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 167 {
 168         ASSERT_OVSL();
 169         return ovs_lookup_vport(dp, port_no);
 170 }
 171
 172 extern struct notifier_block ovs_dp_device_notifier;
 173 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
 174
 175 void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
 176 void ovs_dp_detach_port(struct vport *);
 177 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 178                   const struct dp_upcall_info *);
 179
 180 const char *ovs_dp_name(const struct datapath *dp);
 181 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 182                                          u8 cmd);
 183
 184 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb);
 185 void ovs_dp_notify_wq(struct work_struct *work);
 186 #endif /* datapath.h */