datapath/datapath.h

   1 /*
   2  * Copyright (c) 2009 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/workqueue.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/version.h>
  21 #include "flow.h"
  22 #include "dp_sysfs.h"
  23
  24 /* Mask for the priority bits in a vlan header.  If we ever merge upstream
  25  * then this should go into include/linux/if_vlan.h. */
  26 #define VLAN_PCP_MASK 0xe000
  27
  28 #define DP_MAX_PORTS 256
  29 #define DP_MAX_GROUPS 16
  30
  31 #define DP_L2_BITS (PAGE_SHIFT - ilog2(sizeof(struct dp_bucket*)))
  32 #define DP_L2_SIZE (1 << DP_L2_BITS)
  33 #define DP_L2_SHIFT 0
  34
  35 #define DP_L1_BITS (PAGE_SHIFT - ilog2(sizeof(struct dp_bucket**)))
  36 #define DP_L1_SIZE (1 << DP_L1_BITS)
  37 #define DP_L1_SHIFT DP_L2_BITS
  38
  39 /* For 4 kB pages, this is 1,048,576 on 32-bit or 262,144 on 64-bit. */
  40 #define DP_MAX_BUCKETS (DP_L1_SIZE * DP_L2_SIZE)
  41
  42 /**
  43  * struct dp_table - flow table
  44  * @n_buckets: number of buckets (a power of 2 between %DP_L1_SIZE and
  45  * %DP_MAX_BUCKETS)
  46  * @buckets: pointer to @n_buckets/%DP_L1_SIZE pointers to %DP_L1_SIZE pointers
  47  * to buckets
  48  * @hash_seed: random number used for flow hashing, to make the hash
  49  * distribution harder to predict
  50  * @rcu: RCU callback structure
  51  *
  52  * The @buckets array is logically an array of pointers to buckets.  It is
  53  * broken into two levels to avoid the need to kmalloc() any object larger than
  54  * a single page or to use vmalloc().  @buckets is always nonnull, as is each
  55  * @buckets[i], but each @buckets[i][j] is nonnull only if the specified hash
  56  * bucket is nonempty (for 0 <= i < @n_buckets/%DP_L1_SIZE, 0 <= j <
  57  * %DP_L1_SIZE).
  58  */
  59 struct dp_table {
  60         unsigned int n_buckets;
  61         struct dp_bucket ***buckets;
  62         unsigned int hash_seed;
  63         struct rcu_head rcu;
  64 };
  65
  66 /**
  67  * struct dp_bucket - single bucket within datapath flow table
  68  * @rcu: RCU callback structure
  69  * @n_flows: number of flows in @flows[] array
  70  * @flows: array of @n_flows pointers to flows
  71  *
  72  * The expected number of flows per bucket is 1, but this allows for an
  73  * arbitrary number of collisions.
  74  */
  75 struct dp_bucket {
  76         struct rcu_head rcu;
  77         unsigned int n_flows;
  78         struct sw_flow *flows[];
  79 };
  80
  81 #define DP_N_QUEUES 2
  82 #define DP_MAX_QUEUE_LEN 100
  83
  84 struct dp_stats_percpu {
  85         u64 n_frags;
  86         u64 n_hit;
  87         u64 n_missed;
  88         u64 n_lost;
  89 };
  90
  91 struct dp_port_group {
  92         struct rcu_head rcu;
  93         int n_ports;
  94         u16 ports[];
  95 };
  96
  97 struct datapath {
  98         struct mutex mutex;
  99         int dp_idx;
 100
 101         struct kobject ifobj;
 102
 103         int drop_frags;
 104
 105         /* Queued data. */
 106         struct sk_buff_head queues[DP_N_QUEUES];
 107         wait_queue_head_t waitqueue;
 108
 109         /* Flow table. */
 110         unsigned int n_flows;
 111         struct dp_table *table;
 112
 113         /* Port groups. */
 114         struct dp_port_group *groups[DP_MAX_GROUPS];
 115
 116         /* Switch ports. */
 117         unsigned int n_ports;
 118         struct net_bridge_port *ports[DP_MAX_PORTS];
 119         struct list_head port_list; /* All ports, including local_port. */
 120
 121         /* Stats. */
 122         struct dp_stats_percpu *stats_percpu;
 123 };
 124
 125 struct net_bridge_port {
 126         u16 port_no;
 127         struct datapath *dp;
 128         struct net_device *dev;
 129         struct kobject kobj;
 130         char linkname[IFNAMSIZ];
 131         struct list_head node;   /* Element in datapath.ports. */
 132 };
 133
 134 extern struct notifier_block dp_device_notifier;
 135 extern int (*dp_ioctl_hook)(struct net_device *dev, struct ifreq *rq, int cmd);
 136
 137 /* Flow table. */
 138 struct dp_table *dp_table_create(unsigned int n_buckets);
 139 void dp_table_destroy(struct dp_table *, int free_flows);
 140 struct sw_flow *dp_table_lookup(struct dp_table *, const struct odp_flow_key *);
 141 int dp_table_insert(struct dp_table *, struct sw_flow *);
 142 int dp_table_delete(struct dp_table *, struct sw_flow *);
 143 int dp_table_expand(struct datapath *);
 144 int dp_table_flush(struct datapath *);
 145 int dp_table_foreach(struct dp_table *table,
 146                      int (*callback)(struct sw_flow *flow, void *aux),
 147                      void *aux);
 148
 149 void dp_process_received_packet(struct sk_buff *, struct net_bridge_port *);
 150 int dp_del_port(struct net_bridge_port *);
 151 int dp_output_control(struct datapath *, struct sk_buff *, int, u32 arg);
 152 int dp_min_mtu(const struct datapath *dp);
 153
 154 struct datapath *get_dp(int dp_idx);
 155
 156 static inline const char *dp_name(const struct datapath *dp)
 157 {
 158         return dp->ports[ODPP_LOCAL]->dev->name;
 159 }
 160
 161 #ifdef CONFIG_XEN
 162 int skb_checksum_setup(struct sk_buff *skb);
 163 #else
 164 static inline int skb_checksum_setup(struct sk_buff *skb)
 165 {
 166         return 0;
 167 }
 168 #endif
 169
 170 int vswitch_skb_checksum_setup(struct sk_buff *skb);
 171
 172 #endif /* datapath.h */