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#include <net/ip_tunnels.h>
  29
  30#include "conntrack.h"
  31#include "flow.h"
  32#include "flow_table.h"
  33
  34#define DP_MAX_PORTS           USHRT_MAX
  35#define DP_VPORT_HASH_BUCKETS  1024
  36
  37#define SAMPLE_ACTION_DEPTH 3
  38
  39/**
  40 * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  41 * datapath.
  42 * @n_hit: Number of received packets for which a matching flow was found in
  43 * the flow table.
  44 * @n_miss: Number of received packets that had no matching flow in the flow
  45 * table.  The sum of @n_hit and @n_miss is the number of packets that have
  46 * been received by the datapath.
  47 * @n_lost: Number of received packets that had no matching flow in the flow
  48 * table that could not be sent to userspace (normally due to an overflow in
  49 * one of the datapath's queues).
  50 * @n_mask_hit: Number of masks looked up for flow match.
  51 *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
  52 *   up per packet.
  53 */
  54struct dp_stats_percpu {
  55        u64 n_hit;
  56        u64 n_missed;
  57        u64 n_lost;
  58        u64 n_mask_hit;
  59        struct u64_stats_sync syncp;
  60};
  61
  62/**
  63 * struct datapath - datapath for flow-based packet switching
  64 * @rcu: RCU callback head for deferred destruction.
  65 * @list_node: Element in global 'dps' list.
  66 * @table: flow table.
  67 * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  68 * ovs_mutex and RCU.
  69 * @stats_percpu: Per-CPU datapath statistics.
  70 * @net: Reference to net namespace.
  71 *
  72 * Context: See the comment on locking at the top of datapath.c for additional
  73 * locking information.
  74 */
  75struct datapath {
  76        struct rcu_head rcu;
  77        struct list_head list_node;
  78
  79        /* Flow table. */
  80        struct flow_table table;
  81
  82        /* Switch ports. */
  83        struct hlist_head *ports;
  84
  85        /* Stats. */
  86        struct dp_stats_percpu __percpu *stats_percpu;
  87
  88        /* Network namespace ref. */
  89        possible_net_t net;
  90
  91        u32 user_features;
  92};
  93
  94/**
  95 * struct ovs_skb_cb - OVS data in skb CB
  96 * @input_vport: The original vport packet came in on. This value is cached
  97 * when a packet is received by OVS.
  98 * @mru: The maximum received fragement size; 0 if the packet is not
  99 * fragmented.
 100 */
 101struct ovs_skb_cb {
 102        struct vport            *input_vport;
 103        u16                     mru;
 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 * @userdata: If nonnull, its variable-length value is passed to userspace as
 111 * %OVS_PACKET_ATTR_USERDATA.
 112 * @portid: Netlink portid to which packet should be sent.  If @portid is 0
 113 * then no packet is sent and the packet is accounted in the datapath's @n_lost
 114 * counter.
 115 * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
 116 * @mru: If not zero, Maximum received IP fragment size.
 117 */
 118struct dp_upcall_info {
 119        struct ip_tunnel_info *egress_tun_info;
 120        const struct nlattr *userdata;
 121        const struct nlattr *actions;
 122        int actions_len;
 123        u32 portid;
 124        u8 cmd;
 125        u16 mru;
 126};
 127
 128/**
 129 * struct ovs_net - Per net-namespace data for ovs.
 130 * @dps: List of datapaths to enable dumping them all out.
 131 * Protected by genl_mutex.
 132 */
 133struct ovs_net {
 134        struct list_head dps;
 135        struct work_struct dp_notify_work;
 136
 137        /* Module reference for configuring conntrack. */
 138        bool xt_label;
 139};
 140
 141extern int ovs_net_id;
 142void ovs_lock(void);
 143void ovs_unlock(void);
 144
 145#ifdef CONFIG_LOCKDEP
 146int lockdep_ovsl_is_held(void);
 147#else
 148#define lockdep_ovsl_is_held()  1
 149#endif
 150
 151#define ASSERT_OVSL()           WARN_ON(!lockdep_ovsl_is_held())
 152#define ovsl_dereference(p)                                     \
 153        rcu_dereference_protected(p, lockdep_ovsl_is_held())
 154#define rcu_dereference_ovsl(p)                                 \
 155        rcu_dereference_check(p, lockdep_ovsl_is_held())
 156
 157static inline struct net *ovs_dp_get_net(const struct datapath *dp)
 158{
 159        return read_pnet(&dp->net);
 160}
 161
 162static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 163{
 164        write_pnet(&dp->net, net);
 165}
 166
 167struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 168
 169static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 170{
 171        WARN_ON_ONCE(!rcu_read_lock_held());
 172        return ovs_lookup_vport(dp, port_no);
 173}
 174
 175static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 176{
 177        WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 178        return ovs_lookup_vport(dp, port_no);
 179}
 180
 181static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 182{
 183        ASSERT_OVSL();
 184        return ovs_lookup_vport(dp, port_no);
 185}
 186
 187extern struct notifier_block ovs_dp_device_notifier;
 188extern struct genl_family dp_vport_genl_family;
 189
 190void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
 191void ovs_dp_detach_port(struct vport *);
 192int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 193                  const struct sw_flow_key *, const struct dp_upcall_info *);
 194
 195const char *ovs_dp_name(const struct datapath *dp);
 196struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 197                                         u8 cmd);
 198
 199int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 200                        const struct sw_flow_actions *, struct sw_flow_key *);
 201
 202void ovs_dp_notify_wq(struct work_struct *work);
 203
 204int action_fifos_init(void);
 205void action_fifos_exit(void);
 206
 207/* 'KEY' must not have any bits set outside of the 'MASK' */
 208#define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
 209#define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
 210
 211#define OVS_NLERR(logging_allowed, fmt, ...)                    \
 212do {                                                            \
 213        if (logging_allowed && net_ratelimit())                 \
 214                pr_info("netlink: " fmt "\n", ##__VA_ARGS__);   \
 215} while (0)
 216#endif /* datapath.h */
 217