LXR linux/net/openvswitch/datapath.h

   1/*
   2 * Copyright (c) 2007-2014 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 */
  53struct 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 syncp;
  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 */
  74struct 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        u32 user_features;
  93};
  94
  95/**
  96 * struct ovs_skb_cb - OVS data in skb CB
  97 * @flow: The flow associated with this packet.  May be %NULL if no flow.
  98 * @egress_tun_key: Tunnel information about this packet on egress path.
  99 * NULL if the packet is not being tunneled.
 100 * @input_vport: The original vport packet came in on. This value is cached
 101 * when a packet is received by OVS.
 102 */
 103struct ovs_skb_cb {
 104        struct sw_flow          *flow;
 105        struct ovs_tunnel_info  *egress_tun_info;
 106        struct vport            *input_vport;
 107};
 108#define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 109
 110/**
 111 * struct dp_upcall - metadata to include with a packet to send to userspace
 112 * @cmd: One of %OVS_PACKET_CMD_*.
 113 * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
 114 * @userdata: If nonnull, its variable-length value is passed to userspace as
 115 * %OVS_PACKET_ATTR_USERDATA.
 116 * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
 117 * packet is sent and the packet is accounted in the datapath's @n_lost
 118 * counter.
 119 */
 120struct dp_upcall_info {
 121        u8 cmd;
 122        const struct sw_flow_key *key;
 123        const struct nlattr *userdata;
 124        u32 portid;
 125};
 126
 127/**
 128 * struct ovs_net - Per net-namespace data for ovs.
 129 * @dps: List of datapaths to enable dumping them all out.
 130 * Protected by genl_mutex.
 131 */
 132struct ovs_net {
 133        struct list_head dps;
 134        struct work_struct dp_notify_work;
 135        struct vport_net vport_net;
 136};
 137
 138extern int ovs_net_id;
 139void ovs_lock(void);
 140void ovs_unlock(void);
 141
 142#ifdef CONFIG_LOCKDEP
 143int lockdep_ovsl_is_held(void);
 144#else
 145#define lockdep_ovsl_is_held()  1
 146#endif
 147
 148#define ASSERT_OVSL()           WARN_ON(!lockdep_ovsl_is_held())
 149#define ovsl_dereference(p)                                     \
 150        rcu_dereference_protected(p, lockdep_ovsl_is_held())
 151#define rcu_dereference_ovsl(p)                                 \
 152        rcu_dereference_check(p, lockdep_ovsl_is_held())
 153
 154static inline struct net *ovs_dp_get_net(struct datapath *dp)
 155{
 156        return read_pnet(&dp->net);
 157}
 158
 159static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 160{
 161        write_pnet(&dp->net, net);
 162}
 163
 164struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 165
 166static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 167{
 168        WARN_ON_ONCE(!rcu_read_lock_held());
 169        return ovs_lookup_vport(dp, port_no);
 170}
 171
 172static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 173{
 174        WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 175        return ovs_lookup_vport(dp, port_no);
 176}
 177
 178static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 179{
 180        ASSERT_OVSL();
 181        return ovs_lookup_vport(dp, port_no);
 182}
 183
 184extern struct notifier_block ovs_dp_device_notifier;
 185extern struct genl_family dp_vport_genl_family;
 186
 187void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
 188void ovs_dp_detach_port(struct vport *);
 189int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 190                  const struct dp_upcall_info *);
 191
 192const char *ovs_dp_name(const struct datapath *dp);
 193struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 194                                         u8 cmd);
 195
 196int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 197                        struct sw_flow_key *);
 198
 199void ovs_dp_notify_wq(struct work_struct *work);
 200
 201int action_fifos_init(void);
 202void action_fifos_exit(void);
 203
 204#define OVS_NLERR(fmt, ...)                                     \
 205do {                                                            \
 206        if (net_ratelimit())                                    \
 207                pr_info("netlink: " fmt, ##__VA_ARGS__);        \
 208} while (0)
 209#endif /* datapath.h */
 210