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