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 #include "meter.h"
  34 #include "vport-internal_dev.h"
  35
  36 #define DP_MAX_PORTS           USHRT_MAX
  37 #define DP_VPORT_HASH_BUCKETS  1024
  38
  39 /**
  40  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  41  * datapath.
  42  * @n_hit: Number of received packets for which a matching flow was found in
  43  * the flow table.
  44  * @n_miss: Number of received packets that had no matching flow in the flow
  45  * table.  The sum of @n_hit and @n_miss is the number of packets that have
  46  * been received by the datapath.
  47  * @n_lost: Number of received packets that had no matching flow in the flow
  48  * table that could not be sent to userspace (normally due to an overflow in
  49  * one of the datapath's queues).
  50  * @n_mask_hit: Number of masks looked up for flow match.
  51  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
  52  *   up per packet.
  53  */
  54 struct dp_stats_percpu {
  55         u64 n_hit;
  56         u64 n_missed;
  57         u64 n_lost;
  58         u64 n_mask_hit;
  59         struct u64_stats_sync syncp;
  60 };
  61
  62 /**
  63  * struct datapath - datapath for flow-based packet switching
  64  * @rcu: RCU callback head for deferred destruction.
  65  * @list_node: Element in global 'dps' list.
  66  * @table: flow table.
  67  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  68  * ovs_mutex and RCU.
  69  * @stats_percpu: Per-CPU datapath statistics.
  70  * @net: Reference to net namespace.
  71  * @max_headroom: the maximum headroom of all vports in this datapath; it will
  72  * be used by all the internal vports in this dp.
  73  *
  74  * Context: See the comment on locking at the top of datapath.c for additional
  75  * locking information.
  76  */
  77 struct datapath {
  78         struct rcu_head rcu;
  79         struct list_head list_node;
  80
  81         /* Flow table. */
  82         struct flow_table table;
  83
  84         /* Switch ports. */
  85         struct hlist_head *ports;
  86
  87         /* Stats. */
  88         struct dp_stats_percpu __percpu *stats_percpu;
  89
  90         /* Network namespace ref. */
  91         possible_net_t net;
  92
  93         u32 user_features;
  94
  95         u32 max_headroom;
  96
  97         /* Switch meters. */
  98         struct hlist_head *meters;
  99 };
 100
 101 /**
 102  * struct ovs_skb_cb - OVS data in skb CB
 103  * @input_vport: The original vport packet came in on. This value is cached
 104  * when a packet is received by OVS.
 105  * @mru: The maximum received fragement size; 0 if the packet is not
 106  * fragmented.
 107  * @acts_origlen: The netlink size of the flow actions applied to this skb.
 108  * @cutlen: The number of bytes from the packet end to be removed.
 109  */
 110 struct ovs_skb_cb {
 111         struct vport            *input_vport;
 112         u16                     mru;
 113         u16                     acts_origlen;
 114         u32                     cutlen;
 115 };
 116 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 117
 118 /**
 119  * struct dp_upcall - metadata to include with a packet to send to userspace
 120  * @cmd: One of %OVS_PACKET_CMD_*.
 121  * @userdata: If nonnull, its variable-length value is passed to userspace as
 122  * %OVS_PACKET_ATTR_USERDATA.
 123  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
 124  * then no packet is sent and the packet is accounted in the datapath's @n_lost
 125  * counter.
 126  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
 127  * @mru: If not zero, Maximum received IP fragment size.
 128  */
 129 struct dp_upcall_info {
 130         struct ip_tunnel_info *egress_tun_info;
 131         const struct nlattr *userdata;
 132         const struct nlattr *actions;
 133         int actions_len;
 134         u32 portid;
 135         u8 cmd;
 136         u16 mru;
 137 };
 138
 139 /**
 140  * struct ovs_net - Per net-namespace data for ovs.
 141  * @dps: List of datapaths to enable dumping them all out.
 142  * Protected by genl_mutex.
 143  */
 144 struct ovs_net {
 145         struct list_head dps;
 146         struct work_struct dp_notify_work;
 147
 148         /* Module reference for configuring conntrack. */
 149         bool xt_label;
 150 };
 151
 152 extern unsigned int ovs_net_id;
 153 void ovs_lock(void);
 154 void ovs_unlock(void);
 155
 156 #ifdef CONFIG_LOCKDEP
 157 int lockdep_ovsl_is_held(void);
 158 #else
 159 #define lockdep_ovsl_is_held()  1
 160 #endif
 161
 162 #define ASSERT_OVSL()           WARN_ON(!lockdep_ovsl_is_held())
 163 #define ovsl_dereference(p)                                     \
 164         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 165 #define rcu_dereference_ovsl(p)                                 \
 166         rcu_dereference_check(p, lockdep_ovsl_is_held())
 167
 168 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
 169 {
 170         return read_pnet(&dp->net);
 171 }
 172
 173 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 174 {
 175         write_pnet(&dp->net, net);
 176 }
 177
 178 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 179
 180 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 181 {
 182         WARN_ON_ONCE(!rcu_read_lock_held());
 183         return ovs_lookup_vport(dp, port_no);
 184 }
 185
 186 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 187 {
 188         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 189         return ovs_lookup_vport(dp, port_no);
 190 }
 191
 192 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 193 {
 194         ASSERT_OVSL();
 195         return ovs_lookup_vport(dp, port_no);
 196 }
 197
 198 /* Must be called with rcu_read_lock. */
 199 static inline struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
 200 {
 201         struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
 202
 203         if (dev) {
 204                 struct vport *vport = ovs_internal_dev_get_vport(dev);
 205
 206                 if (vport)
 207                         return vport->dp;
 208         }
 209
 210         return NULL;
 211 }
 212
 213 /* The caller must hold either ovs_mutex or rcu_read_lock to keep the
 214  * returned dp pointer valid.
 215  */
 216 static inline struct datapath *get_dp(struct net *net, int dp_ifindex)
 217 {
 218         struct datapath *dp;
 219
 220         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 221         rcu_read_lock();
 222         dp = get_dp_rcu(net, dp_ifindex);
 223         rcu_read_unlock();
 224
 225         return dp;
 226 }
 227
 228 extern struct notifier_block ovs_dp_device_notifier;
 229 extern struct genl_family dp_vport_genl_family;
 230
 231 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
 232 void ovs_dp_detach_port(struct vport *);
 233 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 234                   const struct sw_flow_key *, const struct dp_upcall_info *,
 235                   uint32_t cutlen);
 236
 237 const char *ovs_dp_name(const struct datapath *dp);
 238 struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
 239                                          u32 portid, u32 seq, u8 cmd);
 240
 241 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 242                         const struct sw_flow_actions *, struct sw_flow_key *);
 243
 244 void ovs_dp_notify_wq(struct work_struct *work);
 245
 246 int action_fifos_init(void);
 247 void action_fifos_exit(void);
 248
 249 /* 'KEY' must not have any bits set outside of the 'MASK' */
 250 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
 251 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
 252
 253 #define OVS_NLERR(logging_allowed, fmt, ...)                    \
 254 do {                                                            \
 255         if (logging_allowed && net_ratelimit())                 \
 256                 pr_info("netlink: " fmt "\n", ##__VA_ARGS__);   \
 257 } while (0)
 258 #endif /* datapath.h */