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 #include "meter.h"
  35 #include "vport-internal_dev.h"
  36
  37 #define DP_MAX_PORTS           USHRT_MAX
  38 #define DP_VPORT_HASH_BUCKETS  1024
  39
  40 /**
  41  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
  42  * datapath.
  43  * @n_hit: Number of received packets for which a matching flow was found in
  44  * the flow table.
  45  * @n_miss: Number of received packets that had no matching flow in the flow
  46  * table.  The sum of @n_hit and @n_miss is the number of packets that have
  47  * been received by the datapath.
  48  * @n_lost: Number of received packets that had no matching flow in the flow
  49  * table that could not be sent to userspace (normally due to an overflow in
  50  * one of the datapath's queues).
  51  * @n_mask_hit: Number of masks looked up for flow match.
  52  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
  53  *   up per packet.
  54  */
  55 struct dp_stats_percpu {
  56         u64 n_hit;
  57         u64 n_missed;
  58         u64 n_lost;
  59         u64 n_mask_hit;
  60         struct u64_stats_sync syncp;
  61 };
  62
  63 /**
  64  * struct datapath - datapath for flow-based packet switching
  65  * @rcu: RCU callback head for deferred destruction.
  66  * @list_node: Element in global 'dps' list.
  67  * @table: flow table.
  68  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
  69  * ovs_mutex and RCU.
  70  * @stats_percpu: Per-CPU datapath statistics.
  71  * @net: Reference to net namespace.
  72  * @max_headroom: the maximum headroom of all vports in this datapath; it will
  73  * be used by all the internal vports in this dp.
  74  *
  75  * Context: See the comment on locking at the top of datapath.c for additional
  76  * locking information.
  77  */
  78 struct datapath {
  79         struct rcu_head rcu;
  80         struct list_head list_node;
  81
  82         /* Flow table. */
  83         struct flow_table table;
  84
  85         /* Switch ports. */
  86         struct hlist_head *ports;
  87
  88         /* Stats. */
  89         struct dp_stats_percpu __percpu *stats_percpu;
  90
  91         /* Network namespace ref. */
  92         possible_net_t net;
  93
  94         u32 user_features;
  95
  96         u32 max_headroom;
  97
  98         /* Switch meters. */
  99         struct hlist_head *meters;
 100 };
 101
 102 /**
 103  * struct ovs_skb_cb - OVS data in skb CB
 104  * @input_vport: The original vport packet came in on. This value is cached
 105  * when a packet is received by OVS.
 106  * @mru: The maximum received fragement size; 0 if the packet is not
 107  * fragmented.
 108  * @acts_origlen: The netlink size of the flow actions applied to this skb.
 109  * @cutlen: The number of bytes from the packet end to be removed.
 110  */
 111 struct ovs_skb_cb {
 112         struct vport            *input_vport;
 113         u16                     mru;
 114         u16                     acts_origlen;
 115         u32                     cutlen;
 116 };
 117 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
 118
 119 /**
 120  * struct dp_upcall - metadata to include with a packet to send to userspace
 121  * @cmd: One of %OVS_PACKET_CMD_*.
 122  * @userdata: If nonnull, its variable-length value is passed to userspace as
 123  * %OVS_PACKET_ATTR_USERDATA.
 124  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
 125  * then no packet is sent and the packet is accounted in the datapath's @n_lost
 126  * counter.
 127  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
 128  * @mru: If not zero, Maximum received IP fragment size.
 129  */
 130 struct dp_upcall_info {
 131         struct ip_tunnel_info *egress_tun_info;
 132         const struct nlattr *userdata;
 133         const struct nlattr *actions;
 134         int actions_len;
 135         u32 portid;
 136         u8 cmd;
 137         u16 mru;
 138 };
 139
 140 /**
 141  * struct ovs_net - Per net-namespace data for ovs.
 142  * @dps: List of datapaths to enable dumping them all out.
 143  * Protected by genl_mutex.
 144  */
 145 struct ovs_net {
 146         struct list_head dps;
 147         struct work_struct dp_notify_work;
 148 #if     IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
 149         struct ovs_ct_limit_info *ct_limit_info;
 150 #endif
 151
 152         /* Module reference for configuring conntrack. */
 153         bool xt_label;
 154
 155 #ifdef HAVE_INET_FRAG_LRU_MOVE
 156         struct net *net;
 157         struct netns_frags ipv4_frags;
 158         struct netns_frags nf_frags;
 159 #endif
 160 };
 161
 162 extern unsigned int ovs_net_id;
 163 void ovs_lock(void);
 164 void ovs_unlock(void);
 165
 166 #ifdef CONFIG_LOCKDEP
 167 int lockdep_ovsl_is_held(void);
 168 #else
 169 #define lockdep_ovsl_is_held()  1
 170 #endif
 171
 172 #define ASSERT_OVSL()           WARN_ON(!lockdep_ovsl_is_held())
 173 #define ovsl_dereference(p)                                     \
 174         rcu_dereference_protected(p, lockdep_ovsl_is_held())
 175 #define rcu_dereference_ovsl(p)                                 \
 176         rcu_dereference_check(p, lockdep_ovsl_is_held())
 177
 178 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
 179 {
 180         return rpl_read_pnet(&dp->net);
 181 }
 182
 183 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
 184 {
 185         rpl_write_pnet(&dp->net, net);
 186 }
 187
 188 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
 189
 190 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
 191 {
 192         WARN_ON_ONCE(!rcu_read_lock_held());
 193         return ovs_lookup_vport(dp, port_no);
 194 }
 195
 196 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
 197 {
 198         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 199         return ovs_lookup_vport(dp, port_no);
 200 }
 201
 202 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
 203 {
 204         ASSERT_OVSL();
 205         return ovs_lookup_vport(dp, port_no);
 206 }
 207
 208 /* Must be called with rcu_read_lock. */
 209 static inline struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
 210 {
 211         struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
 212
 213         if (dev) {
 214                 struct vport *vport = ovs_internal_dev_get_vport(dev);
 215
 216                 if (vport)
 217                         return vport->dp;
 218         }
 219
 220         return NULL;
 221 }
 222
 223 /* The caller must hold either ovs_mutex or rcu_read_lock to keep the
 224  * returned dp pointer valid.
 225  */
 226 static inline struct datapath *get_dp(struct net *net, int dp_ifindex)
 227 {
 228         struct datapath *dp;
 229
 230         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
 231         rcu_read_lock();
 232         dp = get_dp_rcu(net, dp_ifindex);
 233         rcu_read_unlock();
 234
 235         return dp;
 236 }
 237
 238 extern struct notifier_block ovs_dp_device_notifier;
 239 extern struct genl_family dp_vport_genl_family;
 240 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
 241
 242 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
 243 void ovs_dp_detach_port(struct vport *);
 244 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
 245                   const struct sw_flow_key *, const struct dp_upcall_info *,
 246                   uint32_t cutlen);
 247
 248 const char *ovs_dp_name(const struct datapath *dp);
 249 struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
 250                                          u32 portid, u32 seq, u8 cmd);
 251
 252 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
 253                         const struct sw_flow_actions *, struct sw_flow_key *);
 254
 255 void ovs_dp_notify_wq(struct work_struct *work);
 256
 257 int action_fifos_init(void);
 258 void action_fifos_exit(void);
 259
 260 /* 'KEY' must not have any bits set outside of the 'MASK' */
 261 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
 262 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
 263
 264 #define OVS_NLERR(logging_allowed, fmt, ...)                    \
 265 do {                                                            \
 266         if (logging_allowed && net_ratelimit())                 \
 267                 pr_info("netlink: " fmt "\n", ##__VA_ARGS__);   \
 268 } while (0)
 269 #endif /* datapath.h */