datapath/datapath.h

   1 /*
   2  * Copyright (c) 2007-2011 Nicira Networks.
   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/seqlock.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/version.h>
  29
  30 #include "checksum.h"
  31 #include "compat.h"
  32 #include "flow.h"
  33 #include "dp_sysfs.h"
  34 #include "vlan.h"
  35
  36 struct vport;
  37
  38 #define DP_MAX_PORTS 1024
  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         seqcount_t seqlock;
  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  * @ifobj: Represents /sys/class/net/<devname>/brif.  Protected by RTNL.
  65  * @n_flows: Number of flows currently in flow table.
  66  * @table: Current flow table.  Protected by genl_lock and RCU.
  67  * @ports: Map from port number to &struct vport.  %OVSP_LOCAL port
  68  * always exists, other ports may be %NULL.  Protected by RTNL and RCU.
  69  * @port_list: List of all ports in @ports in arbitrary order.  RTNL required
  70  * to iterate or modify.
  71  * @stats_percpu: Per-CPU datapath statistics.
  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 vport __rcu *ports[DP_MAX_PORTS];
  86         struct list_head port_list;
  87
  88         /* Stats. */
  89         struct dp_stats_percpu __percpu *stats_percpu;
  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  * @tun_id: ID of the tunnel that encapsulated this packet.  It is 0 if the
  96  * @ip_summed: Consistently stores L4 checksumming status across different
  97  * kernel versions.
  98  * @csum_start: Stores the offset from which to start checksumming independent
  99  * of the transport header on all kernel versions.
 100  * packet was not received on a tunnel.
 101  * @vlan_tci: Provides a substitute for the skb->vlan_tci field on kernels
 102  * before 2.6.27.
 103  */
 104 struct ovs_skb_cb {
 105         struct sw_flow          *flow;
 106         __be64                  tun_id;
 107 #ifdef NEED_CSUM_NORMALIZE
 108         enum csum_type          ip_summed;
 109         u16                     csum_start;
 110 #endif
 111 #ifdef NEED_VLAN_FIELD
 112         u16                     vlan_tci;
 113 #endif
 114 };
 115 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 116
 117 /**
 118  * struct dp_upcall - metadata to include with a packet to send to userspace
 119  * @cmd: One of %OVS_PACKET_CMD_*.
 120  * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
 121  * @userdata: If nonnull, its u64 value is extracted and passed to userspace as
 122  * %OVS_PACKET_ATTR_USERDATA.
 123  * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
 124  * packet is sent and the packet is accounted in the datapath's @n_lost
 125  * counter.
 126  */
 127 struct dp_upcall_info {
 128         u8 cmd;
 129         const struct sw_flow_key *key;
 130         const struct nlattr *userdata;
 131         u32 pid;
 132 };
 133
 134 extern struct notifier_block dp_device_notifier;
 135 extern struct genl_multicast_group dp_vport_multicast_group;
 136 extern int (*dp_ioctl_hook)(struct net_device *dev, struct ifreq *rq, int cmd);
 137
 138 void dp_process_received_packet(struct vport *, struct sk_buff *);
 139 void dp_detach_port(struct vport *);
 140 int dp_upcall(struct datapath *, struct sk_buff *,
 141               const struct dp_upcall_info *);
 142
 143 struct datapath *get_dp(int dp_idx);
 144 const char *dp_name(const struct datapath *dp);
 145 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 146                                          u8 cmd);
 147
 148 int execute_actions(struct datapath *dp, struct sk_buff *skb);
 149 #endif /* datapath.h */