LXR linux/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 */
  49struct 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 * @n_flows: Number of flows currently in flow table.
  61 * @table: Current flow table.  Protected by genl_lock and RCU.
  62 * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  63 * RTNL and RCU.
  64 * @stats_percpu: Per-CPU datapath statistics.
  65 * @net: Reference to net namespace.
  66 *
  67 * Context: See the comment on locking at the top of datapath.c for additional
  68 * locking information.
  69 */
  70struct datapath {
  71        struct rcu_head rcu;
  72        struct list_head list_node;
  73
  74        /* Flow table. */
  75        struct flow_table __rcu *table;
  76
  77        /* Switch ports. */
  78        struct hlist_head *ports;
  79
  80        /* Stats. */
  81        struct dp_stats_percpu __percpu *stats_percpu;
  82
  83#ifdef CONFIG_NET_NS
  84        /* Network namespace ref. */
  85        struct net *net;
  86#endif
  87};
  88
  89struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
  90
  91static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
  92{
  93        WARN_ON_ONCE(!rcu_read_lock_held());
  94        return ovs_lookup_vport(dp, port_no);
  95}
  96
  97static inline struct vport *ovs_vport_rtnl_rcu(const struct datapath *dp, int port_no)
  98{
  99        WARN_ON_ONCE(!rcu_read_lock_held() && !rtnl_is_locked());
 100        return ovs_lookup_vport(dp, port_no);
 101}
 102
 103static inline struct vport *ovs_vport_rtnl(const struct datapath *dp, int port_no)
 104{
 105        ASSERT_RTNL();
 106        return ovs_lookup_vport(dp, port_no);
 107}
 108
 109/**
 110 * struct ovs_skb_cb - OVS data in skb CB
 111 * @flow: The flow associated with this packet.  May be %NULL if no flow.
 112 */
 113struct ovs_skb_cb {
 114        struct sw_flow          *flow;
 115};
 116#define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 117
 118/**
 119 * struct dp_upcall - metadata to include with a packet to send to userspace
 120 * @cmd: One of %OVS_PACKET_CMD_*.
 121 * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
 122 * @userdata: If nonnull, its u64 value is extracted and passed to userspace as
 123 * %OVS_PACKET_ATTR_USERDATA.
 124 * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
 125 * packet is sent and the packet is accounted in the datapath's @n_lost
 126 * counter.
 127 */
 128struct dp_upcall_info {
 129        u8 cmd;
 130        const struct sw_flow_key *key;
 131        const struct nlattr *userdata;
 132        u32 portid;
 133};
 134
 135static inline struct net *ovs_dp_get_net(struct datapath *dp)
 136{
 137        return read_pnet(&dp->net);
 138}
 139
 140static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 141{
 142        write_pnet(&dp->net, net);
 143}
 144
 145extern struct notifier_block ovs_dp_device_notifier;
 146extern struct genl_multicast_group ovs_dp_vport_multicast_group;
 147
 148void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
 149void ovs_dp_detach_port(struct vport *);
 150int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 151                  const struct dp_upcall_info *);
 152
 153const char *ovs_dp_name(const struct datapath *dp);
 154struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 155                                         u8 cmd);
 156
 157int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb);
 158#endif /* datapath.h */
 159