datapath/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 "checksum.h"
  30 #include "compat.h"
  31 #include "flow.h"
  32 #include "tunnel.h"
  33 #include "vlan.h"
  34 #include "vport.h"
  35
  36 #define DP_MAX_PORTS            USHRT_MAX
  37 #define DP_VPORT_HASH_BUCKETS   1024
  38
  39 #define SAMPLE_ACTION_DEPTH 3
  40
  41 /**
  42  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  43  * datapath.
  44  * @n_hit: Number of received packets for which a matching flow was found in
  45  * the flow table.
  46  * @n_miss: Number of received packets that had no matching flow in the flow
  47  * table.  The sum of @n_hit and @n_miss is the number of packets that have
  48  * been received by the datapath.
  49  * @n_lost: Number of received packets that had no matching flow in the flow
  50  * table that could not be sent to userspace (normally due to an overflow in
  51  * one of the datapath's queues).
  52  */
  53 struct dp_stats_percpu {
  54         u64 n_hit;
  55         u64 n_missed;
  56         u64 n_lost;
  57         struct u64_stats_sync sync;
  58 };
  59
  60 /**
  61  * struct datapath - datapath for flow-based packet switching
  62  * @rcu: RCU callback head for deferred destruction.
  63  * @list_node: Element in global 'dps' list.
  64  * @table: Current flow table.  Protected by ovs_mutex and RCU.
  65  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  66  * ovs_mutex and RCU.
  67  * @stats_percpu: Per-CPU datapath statistics.
  68  * @net: Reference to net namespace.
  69  *
  70  * Context: See the comment on locking at the top of datapath.c for additional
  71  * locking information.
  72  */
  73 struct datapath {
  74         struct rcu_head rcu;
  75         struct list_head list_node;
  76
  77         /* Flow table. */
  78         struct flow_table __rcu *table;
  79
  80         /* Switch ports. */
  81         struct hlist_head *ports;
  82
  83         /* Stats. */
  84         struct dp_stats_percpu __percpu *stats_percpu;
  85
  86 #ifdef CONFIG_NET_NS
  87         /* Network namespace ref. */
  88         struct net *net;
  89 #endif
  90 };
  91
  92 /**
  93  * struct ovs_skb_cb - OVS data in skb CB
  94  * @flow: The flow associated with this packet.  May be %NULL if no flow.
  95  * @pkt_key: The flow information extracted from the packet.  Must be nonnull.
  96  * @tun_key: Key for the tunnel that encapsulated this packet. NULL if the
  97  * packet is not being tunneled.
  98  * @ip_summed: Consistently stores L4 checksumming status across different
  99  * kernel versions.
 100  * @csum_start: Stores the offset from which to start checksumming independent
 101  * of the transport header on all kernel versions.
 102  * packet was not received on a tunnel.
 103  * @vlan_tci: Provides a substitute for the skb->vlan_tci field on kernels
 104  * before 2.6.27.
 105  */
 106 struct ovs_skb_cb {
 107         struct sw_flow          *flow;
 108         struct sw_flow_key      *pkt_key;
 109         struct ovs_key_ipv4_tunnel  *tun_key;
 110 #ifdef NEED_CSUM_NORMALIZE
 111         enum csum_type          ip_summed;
 112         u16                     csum_start;
 113 #endif
 114 #ifdef NEED_VLAN_FIELD
 115         u16                     vlan_tci;
 116 #endif
 117 };
 118 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 119
 120 /**
 121  * struct dp_upcall - metadata to include with a packet to send to userspace
 122  * @cmd: One of %OVS_PACKET_CMD_*.
 123  * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
 124  * @userdata: If nonnull, its variable-length value is passed to userspace as
 125  * %OVS_PACKET_ATTR_USERDATA.
 126  * @portid: Netlink PID to which packet should be sent.  If @portid is 0 then no
 127  * packet is sent and the packet is accounted in the datapath's @n_lost
 128  * counter.
 129  */
 130 struct dp_upcall_info {
 131         u8 cmd;
 132         const struct sw_flow_key *key;
 133         const struct nlattr *userdata;
 134         u32 portid;
 135 };
 136
 137 /**
 138  * struct ovs_net - Per net-namespace data for ovs.
 139  * @dps: List of datapaths to enable dumping them all out.
 140  * Protected by genl_mutex.
 141  * @vport_net: Per network namespace data for vport.
 142  */
 143 struct ovs_net {
 144         struct list_head dps;
 145         struct vport_net vport_net;
 146         struct work_struct dp_notify_work;
 147 };
 148
 149 extern int ovs_net_id;
 150 void ovs_lock(void);
 151 void ovs_unlock(void);
 152
 153 #ifdef CONFIG_LOCKDEP
 154 int lockdep_ovsl_is_held(void);
 155 #else
 156 #define lockdep_ovsl_is_held()  1
 157 #endif
 158
 159 #define ASSERT_OVSL()           WARN_ON(unlikely(!lockdep_ovsl_is_held()))
 160 #define ovsl_dereference(p)                                     \
 161         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 162
 163 static inline struct net *ovs_dp_get_net(struct datapath *dp)
 164 {
 165         return read_pnet(&dp->net);
 166 }
 167
 168 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 169 {
 170         write_pnet(&dp->net, net);
 171 }
 172
 173 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 174
 175 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 176 {
 177         WARN_ON_ONCE(!rcu_read_lock_held());
 178         return ovs_lookup_vport(dp, port_no);
 179 }
 180
 181 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 182 {
 183         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 184         return ovs_lookup_vport(dp, port_no);
 185 }
 186
 187 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 188 {
 189         ASSERT_OVSL();
 190         return ovs_lookup_vport(dp, port_no);
 191 }
 192
 193 extern struct notifier_block ovs_dp_device_notifier;
 194 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
 195
 196 void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
 197 void ovs_dp_detach_port(struct vport *);
 198 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 199                   const struct dp_upcall_info *);
 200
 201 const char *ovs_dp_name(const struct datapath *dp);
 202 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 portid, u32 seq,
 203                                          u8 cmd);
 204
 205 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb);
 206 void ovs_dp_notify_wq(struct work_struct *work);
 207 #endif /* datapath.h */