net/openvswitch/datapath.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (c) 2007-2014 Nicira, Inc.
   4  */
   5
   6 #ifndef DATAPATH_H
   7 #define DATAPATH_H 1
   8
   9 #include <asm/page.h>
  10 #include <linux/kernel.h>
  11 #include <linux/mutex.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/u64_stats_sync.h>
  15 #include <net/ip_tunnels.h>
  16
  17 #include "conntrack.h"
  18 #include "flow.h"
  19 #include "flow_table.h"
  20 #include "meter.h"
  21 #include "vport-internal_dev.h"
  22
  23 #define DP_MAX_PORTS           USHRT_MAX
  24 #define DP_VPORT_HASH_BUCKETS  1024
  25
  26 /**
  27  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  28  * datapath.
  29  * @n_hit: Number of received packets for which a matching flow was found in
  30  * the flow table.
  31  * @n_miss: Number of received packets that had no matching flow in the flow
  32  * table.  The sum of @n_hit and @n_miss is the number of packets that have
  33  * been received by the datapath.
  34  * @n_lost: Number of received packets that had no matching flow in the flow
  35  * table that could not be sent to userspace (normally due to an overflow in
  36  * one of the datapath's queues).
  37  * @n_mask_hit: Number of masks looked up for flow match.
  38  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
  39  *   up per packet.
  40  */
  41 struct dp_stats_percpu {
  42         u64 n_hit;
  43         u64 n_missed;
  44         u64 n_lost;
  45         u64 n_mask_hit;
  46         struct u64_stats_sync syncp;
  47 };
  48
  49 /**
  50  * struct datapath - datapath for flow-based packet switching
  51  * @rcu: RCU callback head for deferred destruction.
  52  * @list_node: Element in global 'dps' list.
  53  * @table: flow table.
  54  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  55  * ovs_mutex and RCU.
  56  * @stats_percpu: Per-CPU datapath statistics.
  57  * @net: Reference to net namespace.
  58  * @max_headroom: the maximum headroom of all vports in this datapath; it will
  59  * be used by all the internal vports in this dp.
  60  *
  61  * Context: See the comment on locking at the top of datapath.c for additional
  62  * locking information.
  63  */
  64 struct datapath {
  65         struct rcu_head rcu;
  66         struct list_head list_node;
  67
  68         /* Flow table. */
  69         struct flow_table table;
  70
  71         /* Switch ports. */
  72         struct hlist_head *ports;
  73
  74         /* Stats. */
  75         struct dp_stats_percpu __percpu *stats_percpu;
  76
  77         /* Network namespace ref. */
  78         possible_net_t net;
  79
  80         u32 user_features;
  81
  82         u32 max_headroom;
  83
  84         /* Switch meters. */
  85         struct hlist_head *meters;
  86 };
  87
  88 /**
  89  * struct ovs_skb_cb - OVS data in skb CB
  90  * @input_vport: The original vport packet came in on. This value is cached
  91  * when a packet is received by OVS.
  92  * @mru: The maximum received fragement size; 0 if the packet is not
  93  * fragmented.
  94  * @acts_origlen: The netlink size of the flow actions applied to this skb.
  95  * @cutlen: The number of bytes from the packet end to be removed.
  96  */
  97 struct ovs_skb_cb {
  98         struct vport            *input_vport;
  99         u16                     mru;
 100         u16                     acts_origlen;
 101         u32                     cutlen;
 102 };
 103 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 104
 105 /**
 106  * struct dp_upcall - metadata to include with a packet to send to userspace
 107  * @cmd: One of %OVS_PACKET_CMD_*.
 108  * @userdata: If nonnull, its variable-length value is passed to userspace as
 109  * %OVS_PACKET_ATTR_USERDATA.
 110  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
 111  * then no packet is sent and the packet is accounted in the datapath's @n_lost
 112  * counter.
 113  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
 114  * @mru: If not zero, Maximum received IP fragment size.
 115  */
 116 struct dp_upcall_info {
 117         struct ip_tunnel_info *egress_tun_info;
 118         const struct nlattr *userdata;
 119         const struct nlattr *actions;
 120         int actions_len;
 121         u32 portid;
 122         u8 cmd;
 123         u16 mru;
 124 };
 125
 126 /**
 127  * struct ovs_net - Per net-namespace data for ovs.
 128  * @dps: List of datapaths to enable dumping them all out.
 129  * Protected by genl_mutex.
 130  */
 131 struct ovs_net {
 132         struct list_head dps;
 133         struct work_struct dp_notify_work;
 134 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
 135         struct ovs_ct_limit_info *ct_limit_info;
 136 #endif
 137
 138         /* Module reference for configuring conntrack. */
 139         bool xt_label;
 140 };
 141
 142 extern unsigned int ovs_net_id;
 143 void ovs_lock(void);
 144 void ovs_unlock(void);
 145
 146 #ifdef CONFIG_LOCKDEP
 147 int lockdep_ovsl_is_held(void);
 148 #else
 149 #define lockdep_ovsl_is_held()  1
 150 #endif
 151
 152 #define ASSERT_OVSL()           WARN_ON(!lockdep_ovsl_is_held())
 153 #define ovsl_dereference(p)                                     \
 154         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 155 #define rcu_dereference_ovsl(p)                                 \
 156         rcu_dereference_check(p, lockdep_ovsl_is_held())
 157
 158 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
 159 {
 160         return read_pnet(&dp->net);
 161 }
 162
 163 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 164 {
 165         write_pnet(&dp->net, net);
 166 }
 167
 168 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 169
 170 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 171 {
 172         WARN_ON_ONCE(!rcu_read_lock_held());
 173         return ovs_lookup_vport(dp, port_no);
 174 }
 175
 176 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 177 {
 178         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 179         return ovs_lookup_vport(dp, port_no);
 180 }
 181
 182 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 183 {
 184         ASSERT_OVSL();
 185         return ovs_lookup_vport(dp, port_no);
 186 }
 187
 188 /* Must be called with rcu_read_lock. */
 189 static inline struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
 190 {
 191         struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
 192
 193         if (dev) {
 194                 struct vport *vport = ovs_internal_dev_get_vport(dev);
 195
 196                 if (vport)
 197                         return vport->dp;
 198         }
 199
 200         return NULL;
 201 }
 202
 203 /* The caller must hold either ovs_mutex or rcu_read_lock to keep the
 204  * returned dp pointer valid.
 205  */
 206 static inline struct datapath *get_dp(struct net *net, int dp_ifindex)
 207 {
 208         struct datapath *dp;
 209
 210         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 211         rcu_read_lock();
 212         dp = get_dp_rcu(net, dp_ifindex);
 213         rcu_read_unlock();
 214
 215         return dp;
 216 }
 217
 218 extern struct notifier_block ovs_dp_device_notifier;
 219 extern struct genl_family dp_vport_genl_family;
 220
 221 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
 222 void ovs_dp_detach_port(struct vport *);
 223 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 224                   const struct sw_flow_key *, const struct dp_upcall_info *,
 225                   uint32_t cutlen);
 226
 227 const char *ovs_dp_name(const struct datapath *dp);
 228 struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
 229                                          u32 portid, u32 seq, u8 cmd);
 230
 231 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 232                         const struct sw_flow_actions *, struct sw_flow_key *);
 233
 234 void ovs_dp_notify_wq(struct work_struct *work);
 235
 236 int action_fifos_init(void);
 237 void action_fifos_exit(void);
 238
 239 /* 'KEY' must not have any bits set outside of the 'MASK' */
 240 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
 241 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
 242
 243 #define OVS_NLERR(logging_allowed, fmt, ...)                    \
 244 do {                                                            \
 245         if (logging_allowed && net_ratelimit())                 \
 246                 pr_info("netlink: " fmt "\n", ##__VA_ARGS__);   \
 247 } while (0)
 248 #endif /* datapath.h */