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 "dp_sysfs.h"
  32 #include "flow.h"
  33 #include "tunnel.h"
  34 #include "vlan.h"
  35 #include "vport.h"
  36
  37 #define DP_MAX_PORTS            USHRT_MAX
  38 #define DP_VPORT_HASH_BUCKETS   1024
  39
  40 #define SAMPLE_ACTION_DEPTH 3
  41
  42 /**
  43  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  44  * datapath.
  45  * @n_hit: Number of received packets for which a matching flow was found in
  46  * the flow table.
  47  * @n_miss: Number of received packets that had no matching flow in the flow
  48  * table.  The sum of @n_hit and @n_miss is the number of packets that have
  49  * been received by the datapath.
  50  * @n_lost: Number of received packets that had no matching flow in the flow
  51  * table that could not be sent to userspace (normally due to an overflow in
  52  * one of the datapath's queues).
  53  */
  54 struct dp_stats_percpu {
  55         u64 n_hit;
  56         u64 n_missed;
  57         u64 n_lost;
  58         struct u64_stats_sync sync;
  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  * @ifobj: Represents /sys/class/net/<devname>/brif.  Protected by RTNL.
  66  * @n_flows: Number of flows currently in flow table.
  67  * @table: Current flow table.  Protected by genl_lock and RCU.
  68  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  69  * RTNL and RCU.
  70  * @stats_percpu: Per-CPU datapath statistics.
  71  * @net: Reference to net namespace.
  72  *
  73  * Context: See the comment on locking at the top of datapath.c for additional
  74  * locking information.
  75  */
  76 struct datapath {
  77         struct rcu_head rcu;
  78         struct list_head list_node;
  79         struct kobject ifobj;
  80
  81         /* Flow table. */
  82         struct flow_table __rcu *table;
  83
  84         /* Switch ports. */
  85         struct hlist_head *ports;
  86
  87         /* Stats. */
  88         struct dp_stats_percpu __percpu *stats_percpu;
  89
  90 #ifdef CONFIG_NET_NS
  91         /* Network namespace ref. */
  92         struct net *net;
  93 #endif
  94 };
  95
  96 /**
  97  * struct ovs_skb_cb - OVS data in skb CB
  98  * @flow: The flow associated with this packet.  May be %NULL if no flow.
  99  * @tun_id: ID of the tunnel that encapsulated this packet.  It is 0 if the
 100  * @ip_summed: Consistently stores L4 checksumming status across different
 101  * kernel versions.
 102  * @csum_start: Stores the offset from which to start checksumming independent
 103  * of the transport header on all kernel versions.
 104  * packet was not received on a tunnel.
 105  * @vlan_tci: Provides a substitute for the skb->vlan_tci field on kernels
 106  * before 2.6.27.
 107  */
 108 struct ovs_skb_cb {
 109         struct sw_flow          *flow;
 110         __be64                  tun_id;
 111 #ifdef NEED_CSUM_NORMALIZE
 112         enum csum_type          ip_summed;
 113         u16                     csum_start;
 114 #endif
 115 #ifdef NEED_VLAN_FIELD
 116         u16                     vlan_tci;
 117 #endif
 118 };
 119 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 120
 121 /**
 122  * struct dp_upcall - metadata to include with a packet to send to userspace
 123  * @cmd: One of %OVS_PACKET_CMD_*.
 124  * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
 125  * @userdata: If nonnull, its u64 value is extracted and passed to userspace as
 126  * %OVS_PACKET_ATTR_USERDATA.
 127  * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
 128  * packet is sent and the packet is accounted in the datapath's @n_lost
 129  * counter.
 130  */
 131 struct dp_upcall_info {
 132         u8 cmd;
 133         const struct sw_flow_key *key;
 134         const struct nlattr *userdata;
 135         u32 pid;
 136 };
 137
 138 /**
 139  * struct ovs_net - Per net-namespace data for ovs.
 140  * @dps: List of datapaths to enable dumping them all out.
 141  * Protected by genl_mutex.
 142  * @vport_net: Per network namespace data for vport.
 143  */
 144 struct ovs_net {
 145         struct list_head dps;
 146         struct vport_net vport_net;
 147 };
 148
 149 extern int ovs_net_id;
 150
 151 static inline struct net *ovs_dp_get_net(struct datapath *dp)
 152 {
 153         return read_pnet(&dp->net);
 154 }
 155
 156 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 157 {
 158         write_pnet(&dp->net, net);
 159 }
 160
 161 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 162
 163 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 164 {
 165         WARN_ON_ONCE(!rcu_read_lock_held());
 166         return ovs_lookup_vport(dp, port_no);
 167 }
 168
 169 static inline struct vport *ovs_vport_rtnl_rcu(const struct datapath *dp, int port_no)
 170 {
 171         WARN_ON_ONCE(!rcu_read_lock_held() && !rtnl_is_locked());
 172         return ovs_lookup_vport(dp, port_no);
 173 }
 174
 175 static inline struct vport *ovs_vport_rtnl(const struct datapath *dp, int port_no)
 176 {
 177         ASSERT_RTNL();
 178         return ovs_lookup_vport(dp, port_no);
 179 }
 180
 181 extern struct notifier_block ovs_dp_device_notifier;
 182 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
 183 extern int (*ovs_dp_ioctl_hook)(struct net_device *dev, struct ifreq *rq, int cmd);
 184
 185 void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
 186 void ovs_dp_detach_port(struct vport *);
 187 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 188                   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 #endif /* datapath.h */