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 "flow_table.h"
  31 #include "vport.h"
  32
  33 #define DP_MAX_PORTS           USHRT_MAX
  34 #define DP_VPORT_HASH_BUCKETS  1024
  35
  36 #define SAMPLE_ACTION_DEPTH 3
  37
  38 /**
  39  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  40  * datapath.
  41  * @n_hit: Number of received packets for which a matching flow was found in
  42  * the flow table.
  43  * @n_miss: Number of received packets that had no matching flow in the flow
  44  * table.  The sum of @n_hit and @n_miss is the number of packets that have
  45  * been received by the datapath.
  46  * @n_lost: Number of received packets that had no matching flow in the flow
  47  * table that could not be sent to userspace (normally due to an overflow in
  48  * one of the datapath's queues).
  49  * @n_mask_hit: Number of masks looked up for flow match.
  50  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
  51  *   up per packet.
  52  */
  53 struct dp_stats_percpu {
  54         u64 n_hit;
  55         u64 n_missed;
  56         u64 n_lost;
  57         u64 n_mask_hit;
  58         struct u64_stats_sync sync;
  59 };
  60
  61 /**
  62  * struct datapath - datapath for flow-based packet switching
  63  * @rcu: RCU callback head for deferred destruction.
  64  * @list_node: Element in global 'dps' list.
  65  * @table: flow table.
  66  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  67  * ovs_mutex and RCU.
  68  * @stats_percpu: Per-CPU datapath statistics.
  69  * @net: Reference to net namespace.
  70  *
  71  * Context: See the comment on locking at the top of datapath.c for additional
  72  * locking information.
  73  */
  74 struct datapath {
  75         struct rcu_head rcu;
  76         struct list_head list_node;
  77
  78         /* Flow table. */
  79         struct flow_table table;
  80
  81         /* Switch ports. */
  82         struct hlist_head *ports;
  83
  84         /* Stats. */
  85         struct dp_stats_percpu __percpu *stats_percpu;
  86
  87 #ifdef CONFIG_NET_NS
  88         /* Network namespace ref. */
  89         struct net *net;
  90 #endif
  91 };
  92
  93 /**
  94  * struct ovs_skb_cb - OVS data in skb CB
  95  * @flow: The flow associated with this packet.  May be %NULL if no flow.
  96  * @pkt_key: The flow information extracted from the packet.  Must be nonnull.
  97  * @tun_key: Key for the tunnel that encapsulated this packet. NULL if the
  98  * packet is not being tunneled.
  99  */
 100 struct ovs_skb_cb {
 101         struct sw_flow          *flow;
 102         struct sw_flow_key      *pkt_key;
 103         struct ovs_key_ipv4_tunnel  *tun_key;
 104 };
 105 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 106
 107 /**
 108  * struct dp_upcall - metadata to include with a packet to send to userspace
 109  * @cmd: One of %OVS_PACKET_CMD_*.
 110  * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
 111  * @userdata: If nonnull, its variable-length value is passed to userspace as
 112  * %OVS_PACKET_ATTR_USERDATA.
 113  * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
 114  * packet is sent and the packet is accounted in the datapath's @n_lost
 115  * counter.
 116  */
 117 struct dp_upcall_info {
 118         u8 cmd;
 119         const struct sw_flow_key *key;
 120         const struct nlattr *userdata;
 121         u32 portid;
 122 };
 123
 124 /**
 125  * struct ovs_net - Per net-namespace data for ovs.
 126  * @dps: List of datapaths to enable dumping them all out.
 127  * Protected by genl_mutex.
 128  */
 129 struct ovs_net {
 130         struct list_head dps;
 131         struct work_struct dp_notify_work;
 132         struct vport_net vport_net;
 133 };
 134
 135 extern int ovs_net_id;
 136 void ovs_lock(void);
 137 void ovs_unlock(void);
 138
 139 #ifdef CONFIG_LOCKDEP
 140 int lockdep_ovsl_is_held(void);
 141 #else
 142 #define lockdep_ovsl_is_held()  1
 143 #endif
 144
 145 #define ASSERT_OVSL()           WARN_ON(unlikely(!lockdep_ovsl_is_held()))
 146 #define ovsl_dereference(p)                                     \
 147         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 148
 149 static inline struct net *ovs_dp_get_net(struct datapath *dp)
 150 {
 151         return read_pnet(&dp->net);
 152 }
 153
 154 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 155 {
 156         write_pnet(&dp->net, net);
 157 }
 158
 159 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 160
 161 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 162 {
 163         WARN_ON_ONCE(!rcu_read_lock_held());
 164         return ovs_lookup_vport(dp, port_no);
 165 }
 166
 167 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 168 {
 169         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 170         return ovs_lookup_vport(dp, port_no);
 171 }
 172
 173 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 174 {
 175         ASSERT_OVSL();
 176         return ovs_lookup_vport(dp, port_no);
 177 }
 178
 179 extern struct notifier_block ovs_dp_device_notifier;
 180 extern struct genl_family dp_vport_genl_family;
 181 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
 182
 183 void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
 184 void ovs_dp_detach_port(struct vport *);
 185 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 186                   const struct dp_upcall_info *);
 187
 188 const char *ovs_dp_name(const struct datapath *dp);
 189 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 190                                          u8 cmd);
 191
 192 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb);
 193 void ovs_dp_notify_wq(struct work_struct *work);
 194
 195 #define OVS_NLERR(fmt, ...) \
 196         pr_info_once("netlink: " fmt, ##__VA_ARGS__)
 197
 198 #endif /* datapath.h */