datapath/datapath.h

   1 /*
   2  * Copyright (c) 2007-2015 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/net_namespace.h>
  29 #include <net/ip_tunnels.h>
  30
  31 #include "compat.h"
  32 #include "flow.h"
  33 #include "flow_table.h"
  34
  35 #define DP_MAX_PORTS           USHRT_MAX
  36 #define DP_VPORT_HASH_BUCKETS  1024
  37
  38 /**
  39  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  40  * 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  * @n_mask_hit: Number of masks looked up for flow match.
  50  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
  51  *   up per packet.
  52  */
  53 struct dp_stats_percpu {
  54         u64 n_hit;
  55         u64 n_missed;
  56         u64 n_lost;
  57         u64 n_mask_hit;
  58         struct u64_stats_sync syncp;
  59 };
  60
  61 /**
  62  * struct datapath - datapath for flow-based packet switching
  63  * @rcu: RCU callback head for deferred destruction.
  64  * @list_node: Element in global 'dps' list.
  65  * @table: flow table.
  66  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  67  * ovs_mutex and RCU.
  68  * @stats_percpu: Per-CPU datapath statistics.
  69  * @net: Reference to net namespace.
  70  * @max_headroom: the maximum headroom of all vports in this datapath; it will
  71  * be used by all the internal vports in this dp.
  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
  80         /* Flow table. */
  81         struct flow_table table;
  82
  83         /* Switch ports. */
  84         struct hlist_head *ports;
  85
  86         /* Stats. */
  87         struct dp_stats_percpu __percpu *stats_percpu;
  88
  89         /* Network namespace ref. */
  90         possible_net_t net;
  91
  92         u32 user_features;
  93
  94         u32 max_headroom;
  95 };
  96
  97 /**
  98  * struct ovs_skb_cb - OVS data in skb CB
  99  * @input_vport: The original vport packet came in on. This value is cached
 100  * when a packet is received by OVS.
 101  * @mru: The maximum received fragement size; 0 if the packet is not
 102  * fragmented.
 103  * @acts_origlen: The netlink size of the flow actions applied to this skb.
 104  * @cutlen: The number of bytes from the packet end to be removed.
 105  */
 106 struct ovs_skb_cb {
 107         struct vport            *input_vport;
 108         u16                     mru;
 109         u16                     acts_origlen;
 110         u32                     cutlen;
 111 };
 112 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 113
 114 /**
 115  * struct dp_upcall - metadata to include with a packet to send to userspace
 116  * @cmd: One of %OVS_PACKET_CMD_*.
 117  * @userdata: If nonnull, its variable-length value is passed to userspace as
 118  * %OVS_PACKET_ATTR_USERDATA.
 119  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
 120  * then no packet is sent and the packet is accounted in the datapath's @n_lost
 121  * counter.
 122  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
 123  * @mru: If not zero, Maximum received IP fragment size.
 124  */
 125 struct dp_upcall_info {
 126         struct ip_tunnel_info *egress_tun_info;
 127         const struct nlattr *userdata;
 128         const struct nlattr *actions;
 129         int actions_len;
 130         u32 portid;
 131         u8 cmd;
 132         u16 mru;
 133 };
 134
 135 /**
 136  * struct ovs_net - Per net-namespace data for ovs.
 137  * @dps: List of datapaths to enable dumping them all out.
 138  * Protected by genl_mutex.
 139  */
 140 struct ovs_net {
 141         struct list_head dps;
 142         struct work_struct dp_notify_work;
 143
 144         /* Module reference for configuring conntrack. */
 145         bool xt_label;
 146
 147 #ifdef HAVE_INET_FRAG_LRU_MOVE
 148         struct net *net;
 149         struct netns_frags ipv4_frags;
 150         struct netns_frags nf_frags;
 151 #endif
 152 };
 153
 154 extern unsigned int ovs_net_id;
 155 void ovs_lock(void);
 156 void ovs_unlock(void);
 157
 158 #ifdef CONFIG_LOCKDEP
 159 int lockdep_ovsl_is_held(void);
 160 #else
 161 #define lockdep_ovsl_is_held()  1
 162 #endif
 163
 164 #define ASSERT_OVSL()           WARN_ON(!lockdep_ovsl_is_held())
 165 #define ovsl_dereference(p)                                     \
 166         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 167 #define rcu_dereference_ovsl(p)                                 \
 168         rcu_dereference_check(p, lockdep_ovsl_is_held())
 169
 170 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
 171 {
 172         return rpl_read_pnet(&dp->net);
 173 }
 174
 175 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 176 {
 177         rpl_write_pnet(&dp->net, net);
 178 }
 179
 180 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 181
 182 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 183 {
 184         WARN_ON_ONCE(!rcu_read_lock_held());
 185         return ovs_lookup_vport(dp, port_no);
 186 }
 187
 188 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 189 {
 190         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 191         return ovs_lookup_vport(dp, port_no);
 192 }
 193
 194 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 195 {
 196         ASSERT_OVSL();
 197         return ovs_lookup_vport(dp, port_no);
 198 }
 199
 200 extern struct notifier_block ovs_dp_device_notifier;
 201 extern struct genl_family dp_vport_genl_family;
 202 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
 203
 204 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
 205 void ovs_dp_detach_port(struct vport *);
 206 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 207                   const struct sw_flow_key *, const struct dp_upcall_info *,
 208                   uint32_t cutlen);
 209
 210 const char *ovs_dp_name(const struct datapath *dp);
 211 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
 212                                          u8 cmd);
 213
 214 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 215                         const struct sw_flow_actions *, struct sw_flow_key *);
 216
 217 void ovs_dp_notify_wq(struct work_struct *work);
 218
 219 int action_fifos_init(void);
 220 void action_fifos_exit(void);
 221
 222 /* 'KEY' must not have any bits set outside of the 'MASK' */
 223 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
 224 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
 225
 226 #define OVS_NLERR(logging_allowed, fmt, ...)                    \
 227 do {                                                            \
 228         if (logging_allowed && net_ratelimit())                 \
 229                 pr_info("netlink: " fmt "\n", ##__VA_ARGS__);   \
 230 } while (0)
 231 #endif /* datapath.h */