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 #define DP_MASKS_REBALANCE_INTERVAL 4000
  26
  27 /**
  28  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  29  * datapath.
  30  * @n_hit: Number of received packets for which a matching flow was found in
  31  * the flow table.
  32  * @n_miss: Number of received packets that had no matching flow in the flow
  33  * table.  The sum of @n_hit and @n_miss is the number of packets that have
  34  * been received by the datapath.
  35  * @n_lost: Number of received packets that had no matching flow in the flow
  36  * table that could not be sent to userspace (normally due to an overflow in
  37  * one of the datapath's queues).
  38  * @n_mask_hit: Number of masks looked up for flow match.
  39  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
  40  *   up per packet.
  41  * @n_cache_hit: The number of received packets that had their mask found using
  42  * the mask cache.
  43  */
  44 struct dp_stats_percpu {
  45         u64 n_hit;
  46         u64 n_missed;
  47         u64 n_lost;
  48         u64 n_mask_hit;
  49         u64 n_cache_hit;
  50         struct u64_stats_sync syncp;
  51 };
  52
  53 /**
  54  * struct dp_nlsk_pids - array of netlink portids of for a datapath.
  55  *                       This is used when OVS_DP_F_DISPATCH_UPCALL_PER_CPU
  56  *                       is enabled and must be protected by rcu.
  57  * @rcu: RCU callback head for deferred destruction.
  58  * @n_pids: Size of @pids array.
  59  * @pids: Array storing the Netlink socket PIDs indexed by CPU ID for packets
  60  *       that miss the flow table.
  61  */
  62 struct dp_nlsk_pids {
  63         struct rcu_head rcu;
  64         u32 n_pids;
  65         u32 pids[];
  66 };
  67
  68 /**
  69  * struct datapath - datapath for flow-based packet switching
  70  * @rcu: RCU callback head for deferred destruction.
  71  * @list_node: Element in global 'dps' list.
  72  * @table: flow table.
  73  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  74  * ovs_mutex and RCU.
  75  * @stats_percpu: Per-CPU datapath statistics.
  76  * @net: Reference to net namespace.
  77  * @max_headroom: the maximum headroom of all vports in this datapath; it will
  78  * be used by all the internal vports in this dp.
  79  * @upcall_portids: RCU protected 'struct dp_nlsk_pids'.
  80  *
  81  * Context: See the comment on locking at the top of datapath.c for additional
  82  * locking information.
  83  */
  84 struct datapath {
  85         struct rcu_head rcu;
  86         struct list_head list_node;
  87
  88         /* Flow table. */
  89         struct flow_table table;
  90
  91         /* Switch ports. */
  92         struct hlist_head *ports;
  93
  94         /* Stats. */
  95         struct dp_stats_percpu __percpu *stats_percpu;
  96
  97         /* Network namespace ref. */
  98         possible_net_t net;
  99
 100         u32 user_features;
 101
 102         u32 max_headroom;
 103
 104         /* Switch meters. */
 105         struct dp_meter_table meter_tbl;
 106
 107         struct dp_nlsk_pids __rcu *upcall_portids;
 108 };
 109
 110 /**
 111  * struct ovs_skb_cb - OVS data in skb CB
 112  * @input_vport: The original vport packet came in on. This value is cached
 113  * when a packet is received by OVS.
 114  * @mru: The maximum received fragement size; 0 if the packet is not
 115  * fragmented.
 116  * @acts_origlen: The netlink size of the flow actions applied to this skb.
 117  * @cutlen: The number of bytes from the packet end to be removed.
 118  * @probability: The sampling probability that was applied to this skb; 0 means
 119  * no sampling has occurred; U32_MAX means 100% probability.
 120  */
 121 struct ovs_skb_cb {
 122         struct vport            *input_vport;
 123         u16                     mru;
 124         u16                     acts_origlen;
 125         u32                     cutlen;
 126         u32                     probability;
 127 };
 128 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 129
 130 /**
 131  * struct dp_upcall - metadata to include with a packet to send to userspace
 132  * @cmd: One of %OVS_PACKET_CMD_*.
 133  * @userdata: If nonnull, its variable-length value is passed to userspace as
 134  * %OVS_PACKET_ATTR_USERDATA.
 135  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
 136  * then no packet is sent and the packet is accounted in the datapath's @n_lost
 137  * counter.
 138  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
 139  * @mru: If not zero, Maximum received IP fragment size.
 140  */
 141 struct dp_upcall_info {
 142         struct ip_tunnel_info *egress_tun_info;
 143         const struct nlattr *userdata;
 144         const struct nlattr *actions;
 145         int actions_len;
 146         u32 portid;
 147         u8 cmd;
 148         u16 mru;
 149 };
 150
 151 /**
 152  * struct ovs_net - Per net-namespace data for ovs.
 153  * @dps: List of datapaths to enable dumping them all out.
 154  * Protected by genl_mutex.
 155  */
 156 struct ovs_net {
 157         struct list_head dps;
 158         struct work_struct dp_notify_work;
 159         struct delayed_work masks_rebalance;
 160 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
 161         struct ovs_ct_limit_info *ct_limit_info;
 162 #endif
 163 };
 164
 165 /**
 166  * enum ovs_pkt_hash_types - hash info to include with a packet
 167  * to send to userspace.
 168  * @OVS_PACKET_HASH_SW_BIT: indicates hash was computed in software stack.
 169  * @OVS_PACKET_HASH_L4_BIT: indicates hash is a canonical 4-tuple hash
 170  * over transport ports.
 171  */
 172 enum ovs_pkt_hash_types {
 173         OVS_PACKET_HASH_SW_BIT = (1ULL << 32),
 174         OVS_PACKET_HASH_L4_BIT = (1ULL << 33),
 175 };
 176
 177 extern unsigned int ovs_net_id;
 178 void ovs_lock(void);
 179 void ovs_unlock(void);
 180
 181 #ifdef CONFIG_LOCKDEP
 182 int lockdep_ovsl_is_held(void);
 183 #else
 184 #define lockdep_ovsl_is_held()  1
 185 #endif
 186
 187 #define ASSERT_OVSL()           WARN_ON(!lockdep_ovsl_is_held())
 188 #define ovsl_dereference(p)                                     \
 189         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 190 #define rcu_dereference_ovsl(p)                                 \
 191         rcu_dereference_check(p, lockdep_ovsl_is_held())
 192
 193 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
 194 {
 195         return read_pnet(&dp->net);
 196 }
 197
 198 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 199 {
 200         write_pnet(&dp->net, net);
 201 }
 202
 203 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 204
 205 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 206 {
 207         WARN_ON_ONCE(!rcu_read_lock_held());
 208         return ovs_lookup_vport(dp, port_no);
 209 }
 210
 211 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 212 {
 213         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 214         return ovs_lookup_vport(dp, port_no);
 215 }
 216
 217 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 218 {
 219         ASSERT_OVSL();
 220         return ovs_lookup_vport(dp, port_no);
 221 }
 222
 223 /* Must be called with rcu_read_lock. */
 224 static inline struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
 225 {
 226         struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
 227
 228         if (dev) {
 229                 struct vport *vport = ovs_internal_dev_get_vport(dev);
 230
 231                 if (vport)
 232                         return vport->dp;
 233         }
 234
 235         return NULL;
 236 }
 237
 238 /* The caller must hold either ovs_mutex or rcu_read_lock to keep the
 239  * returned dp pointer valid.
 240  */
 241 static inline struct datapath *get_dp(struct net *net, int dp_ifindex)
 242 {
 243         struct datapath *dp;
 244
 245         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 246         rcu_read_lock();
 247         dp = get_dp_rcu(net, dp_ifindex);
 248         rcu_read_unlock();
 249
 250         return dp;
 251 }
 252
 253 extern struct notifier_block ovs_dp_device_notifier;
 254 extern struct genl_family dp_vport_genl_family;
 255
 256 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
 257 void ovs_dp_detach_port(struct vport *);
 258 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 259                   const struct sw_flow_key *, const struct dp_upcall_info *,
 260                   uint32_t cutlen);
 261
 262 u32 ovs_dp_get_upcall_portid(const struct datapath *dp, uint32_t cpu_id);
 263
 264 const char *ovs_dp_name(const struct datapath *dp);
 265 struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
 266                                          u32 portid, u32 seq, u8 cmd);
 267
 268 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 269                         const struct sw_flow_actions *, struct sw_flow_key *);
 270
 271 void ovs_dp_notify_wq(struct work_struct *work);
 272
 273 int action_fifos_init(void);
 274 void action_fifos_exit(void);
 275
 276 /* 'KEY' must not have any bits set outside of the 'MASK' */
 277 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
 278 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
 279
 280 #define OVS_NLERR(logging_allowed, fmt, ...)                    \
 281 do {                                                            \
 282         if (logging_allowed && net_ratelimit())                 \
 283                 pr_info("netlink: " fmt "\n", ##__VA_ARGS__);   \
 284 } while (0)
 285 #endif /* datapath.h */