datapath/datapath.h

   1 /*
   2  * Copyright (c) 2009, 2010, 2011 Nicira Networks.
   3  * Distributed under the terms of the GNU GPL version 2.
   4  *
   5  * Significant portions of this file may be copied from parts of the Linux
   6  * kernel, by Linus Torvalds and others.
   7  */
   8
   9 /* Interface exported by openvswitch_mod. */
  10
  11 #ifndef DATAPATH_H
  12 #define DATAPATH_H 1
  13
  14 #include <asm/page.h>
  15 #include <linux/kernel.h>
  16 #include <linux/mutex.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/seqlock.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/version.h>
  21
  22 #include "checksum.h"
  23 #include "compat.h"
  24 #include "flow.h"
  25 #include "dp_sysfs.h"
  26 #include "vlan.h"
  27
  28 struct vport;
  29
  30 /* Mask for the priority bits in a vlan header.  If we ever merge upstream
  31  * then this should go into include/linux/if_vlan.h. */
  32 #define VLAN_PCP_MASK 0xe000
  33 #define VLAN_PCP_SHIFT 13
  34
  35 #define DP_MAX_PORTS 1024
  36
  37 /**
  38  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  39  * datapath.
  40  * @n_frags: Number of IP fragments processed by 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  */
  50 struct dp_stats_percpu {
  51         u64 n_frags;
  52         u64 n_hit;
  53         u64 n_missed;
  54         u64 n_lost;
  55         seqcount_t seqlock;
  56 };
  57
  58 /**
  59  * struct datapath - datapath for flow-based packet switching
  60  * @rcu: RCU callback head for deferred destruction.
  61  * @dp_ifindex: ifindex of local port.
  62  * @list_node: Element in global 'dps' list.
  63  * @ifobj: Represents /sys/class/net/<devname>/brif.  Protected by RTNL.
  64  * @drop_frags: Drop all IP fragments if nonzero.
  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  * @sflow_probability: Number of packets out of UINT_MAX to sample to the
  73  * %OVS_PACKET_CMD_SAMPLE multicast group, e.g. (@sflow_probability/UINT_MAX)
  74  * is the probability of sampling a given packet.
  75  *
  76  * Context: See the comment on locking at the top of datapath.c for additional
  77  * locking information.
  78  */
  79 struct datapath {
  80         struct rcu_head rcu;
  81         int dp_ifindex;
  82         struct list_head list_node;
  83         struct kobject ifobj;
  84
  85         int drop_frags;
  86
  87         /* Flow table. */
  88         struct flow_table __rcu *table;
  89
  90         /* Switch ports. */
  91         struct vport __rcu *ports[DP_MAX_PORTS];
  92         struct list_head port_list;
  93
  94         /* Stats. */
  95         struct dp_stats_percpu __percpu *stats_percpu;
  96
  97         /* sFlow Sampling */
  98         unsigned int sflow_probability;
  99 };
 100
 101 /**
 102  * struct ovs_skb_cb - OVS data in skb CB
 103  * @vport: The datapath port on which the skb entered the switch.
 104  * @flow: The flow associated with this packet.  May be %NULL if no flow.
 105  * @tun_id: ID of the tunnel that encapsulated this packet.  It is 0 if the
 106  * @ip_summed: Consistently stores L4 checksumming status across different
 107  * kernel versions.
 108  * @csum_start: Stores the offset from which to start checksumming independent
 109  * of the transport header on all kernel versions.
 110  * packet was not received on a tunnel.
 111  * @vlan_tci: Provides a substitute for the skb->vlan_tci field on kernels
 112  * before 2.6.27.
 113  */
 114 struct ovs_skb_cb {
 115         struct vport            *vport;
 116         struct sw_flow          *flow;
 117         __be64                  tun_id;
 118 #ifdef NEED_CSUM_NORMALIZE
 119         enum csum_type          ip_summed;
 120         u16                     csum_start;
 121 #endif
 122 #ifdef NEED_VLAN_FIELD
 123         u16                     vlan_tci;
 124 #endif
 125 };
 126 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 127
 128 /**
 129  * struct dp_upcall - metadata to include with a packet to send to userspace
 130  * @cmd: One of %OVS_PACKET_CMD_*.
 131  * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
 132  * @userdata: Becomes %OVS_PACKET_ATTR_USERDATA if nonzero.
 133  * @sample_pool: Becomes %OVS_PACKET_ATTR_SAMPLE_POOL if nonzero.
 134  * @actions: Becomes %OVS_PACKET_ATTR_ACTIONS if nonnull.
 135  * @actions_len: Number of bytes in @actions.
 136 */
 137 struct dp_upcall_info {
 138         u8 cmd;
 139         const struct sw_flow_key *key;
 140         u64 userdata;
 141         u32 sample_pool;
 142         const struct nlattr *actions;
 143         u32 actions_len;
 144 };
 145
 146 extern struct notifier_block dp_device_notifier;
 147 extern struct genl_multicast_group dp_vport_multicast_group;
 148 extern int (*dp_ioctl_hook)(struct net_device *dev, struct ifreq *rq, int cmd);
 149
 150 void dp_process_received_packet(struct vport *, struct sk_buff *);
 151 void dp_detach_port(struct vport *);
 152 int dp_upcall(struct datapath *, struct sk_buff *, const struct dp_upcall_info *);
 153
 154 struct datapath *get_dp(int dp_idx);
 155 const char *dp_name(const struct datapath *dp);
 156 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 157                                          u8 cmd);
 158
 159 #endif /* datapath.h */