net/openvswitch/datapath.h

   1 /*
   2  * Copyright (c) 2007-2014 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 #include <net/ip_tunnels.h>
  29
  30 #include "conntrack.h"
  31 #include "flow.h"
  32 #include "flow_table.h"
  33
  34 #define DP_MAX_PORTS           USHRT_MAX
  35 #define DP_VPORT_HASH_BUCKETS  1024
  36
  37 /**
  38  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  39  * datapath.
  40  * @n_hit: Number of received packets for which a matching flow was found in
  41  * the flow table.
  42  * @n_miss: Number of received packets that had no matching flow in the flow
  43  * table.  The sum of @n_hit and @n_miss is the number of packets that have
  44  * been received by the datapath.
  45  * @n_lost: Number of received packets that had no matching flow in the flow
  46  * table that could not be sent to userspace (normally due to an overflow in
  47  * one of the datapath's queues).
  48  * @n_mask_hit: Number of masks looked up for flow match.
  49  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
  50  *   up per packet.
  51  */
  52 struct dp_stats_percpu {
  53         u64 n_hit;
  54         u64 n_missed;
  55         u64 n_lost;
  56         u64 n_mask_hit;
  57         struct u64_stats_sync syncp;
  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: flow table.
  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  * @max_headroom: the maximum headroom of all vports in this datapath; it will
  70  * be used by all the internal vports in this dp.
  71  *
  72  * Context: See the comment on locking at the top of datapath.c for additional
  73  * locking information.
  74  */
  75 struct datapath {
  76         struct rcu_head rcu;
  77         struct list_head list_node;
  78
  79         /* Flow table. */
  80         struct flow_table table;
  81
  82         /* Switch ports. */
  83         struct hlist_head *ports;
  84
  85         /* Stats. */
  86         struct dp_stats_percpu __percpu *stats_percpu;
  87
  88         /* Network namespace ref. */
  89         possible_net_t net;
  90
  91         u32 user_features;
  92
  93         u32 max_headroom;
  94 };
  95
  96 /**
  97  * struct ovs_skb_cb - OVS data in skb CB
  98  * @input_vport: The original vport packet came in on. This value is cached
  99  * when a packet is received by OVS.
 100  * @mru: The maximum received fragement size; 0 if the packet is not
 101  * fragmented.
 102  * @acts_origlen: The netlink size of the flow actions applied to this skb.
 103  * @cutlen: The number of bytes from the packet end to be removed.
 104  */
 105 struct ovs_skb_cb {
 106         struct vport            *input_vport;
 107         u16                     mru;
 108         u16                     acts_origlen;
 109         u32                     cutlen;
 110 };
 111 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 112
 113 /**
 114  * struct dp_upcall - metadata to include with a packet to send to userspace
 115  * @cmd: One of %OVS_PACKET_CMD_*.
 116  * @userdata: If nonnull, its variable-length value is passed to userspace as
 117  * %OVS_PACKET_ATTR_USERDATA.
 118  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
 119  * then no packet is sent and the packet is accounted in the datapath's @n_lost
 120  * counter.
 121  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
 122  * @mru: If not zero, Maximum received IP fragment size.
 123  */
 124 struct dp_upcall_info {
 125         struct ip_tunnel_info *egress_tun_info;
 126         const struct nlattr *userdata;
 127         const struct nlattr *actions;
 128         int actions_len;
 129         u32 portid;
 130         u8 cmd;
 131         u16 mru;
 132 };
 133
 134 /**
 135  * struct ovs_net - Per net-namespace data for ovs.
 136  * @dps: List of datapaths to enable dumping them all out.
 137  * Protected by genl_mutex.
 138  */
 139 struct ovs_net {
 140         struct list_head dps;
 141         struct work_struct dp_notify_work;
 142
 143         /* Module reference for configuring conntrack. */
 144         bool xt_label;
 145 };
 146
 147 extern unsigned int ovs_net_id;
 148 void ovs_lock(void);
 149 void ovs_unlock(void);
 150
 151 #ifdef CONFIG_LOCKDEP
 152 int lockdep_ovsl_is_held(void);
 153 #else
 154 #define lockdep_ovsl_is_held()  1
 155 #endif
 156
 157 #define ASSERT_OVSL()           WARN_ON(!lockdep_ovsl_is_held())
 158 #define ovsl_dereference(p)                                     \
 159         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 160 #define rcu_dereference_ovsl(p)                                 \
 161         rcu_dereference_check(p, lockdep_ovsl_is_held())
 162
 163 static inline struct net *ovs_dp_get_net(const 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_family dp_vport_genl_family;
 195
 196 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
 197 void ovs_dp_detach_port(struct vport *);
 198 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 199                   const struct sw_flow_key *, const struct dp_upcall_info *,
 200                   uint32_t cutlen);
 201
 202 const char *ovs_dp_name(const struct datapath *dp);
 203 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 204                                          u8 cmd);
 205
 206 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 207                         const struct sw_flow_actions *, struct sw_flow_key *);
 208
 209 void ovs_dp_notify_wq(struct work_struct *work);
 210
 211 int action_fifos_init(void);
 212 void action_fifos_exit(void);
 213
 214 /* 'KEY' must not have any bits set outside of the 'MASK' */
 215 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
 216 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
 217
 218 #define OVS_NLERR(logging_allowed, fmt, ...)                    \
 219 do {                                                            \
 220         if (logging_allowed && net_ratelimit())                 \
 221                 pr_info("netlink: " fmt "\n", ##__VA_ARGS__);   \
 222 } while (0)
 223 #endif /* datapath.h */