xref: /linux/net/openvswitch/datapath.h (revision b889fcf63cb62e7fdb7816565e28f44dbe4a76a5)
1 /*
2  * Copyright (c) 2007-2012 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 
29 #include "flow.h"
30 #include "vport.h"
31 
32 #define DP_MAX_PORTS           USHRT_MAX
33 #define DP_VPORT_HASH_BUCKETS  1024
34 
35 #define SAMPLE_ACTION_DEPTH 3
36 
37 /**
38  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
39  * datapath.
40  * @n_hit: Number of received packets for which a matching flow was found in
41  * the flow table.
42  * @n_miss: Number of received packets that had no matching flow in the flow
43  * table.  The sum of @n_hit and @n_miss is the number of packets that have
44  * been received by the datapath.
45  * @n_lost: Number of received packets that had no matching flow in the flow
46  * table that could not be sent to userspace (normally due to an overflow in
47  * one of the datapath's queues).
48  */
49 struct dp_stats_percpu {
50 	u64 n_hit;
51 	u64 n_missed;
52 	u64 n_lost;
53 	struct u64_stats_sync sync;
54 };
55 
56 /**
57  * struct datapath - datapath for flow-based packet switching
58  * @rcu: RCU callback head for deferred destruction.
59  * @list_node: Element in global 'dps' list.
60  * @n_flows: Number of flows currently in flow table.
61  * @table: Current flow table.  Protected by genl_lock and RCU.
62  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
63  * RTNL and RCU.
64  * @stats_percpu: Per-CPU datapath statistics.
65  * @net: Reference to net namespace.
66  *
67  * Context: See the comment on locking at the top of datapath.c for additional
68  * locking information.
69  */
70 struct datapath {
71 	struct rcu_head rcu;
72 	struct list_head list_node;
73 
74 	/* Flow table. */
75 	struct flow_table __rcu *table;
76 
77 	/* Switch ports. */
78 	struct hlist_head *ports;
79 
80 	/* Stats. */
81 	struct dp_stats_percpu __percpu *stats_percpu;
82 
83 #ifdef CONFIG_NET_NS
84 	/* Network namespace ref. */
85 	struct net *net;
86 #endif
87 };
88 
89 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
90 
91 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
92 {
93 	WARN_ON_ONCE(!rcu_read_lock_held());
94 	return ovs_lookup_vport(dp, port_no);
95 }
96 
97 static inline struct vport *ovs_vport_rtnl_rcu(const struct datapath *dp, int port_no)
98 {
99 	WARN_ON_ONCE(!rcu_read_lock_held() && !rtnl_is_locked());
100 	return ovs_lookup_vport(dp, port_no);
101 }
102 
103 static inline struct vport *ovs_vport_rtnl(const struct datapath *dp, int port_no)
104 {
105 	ASSERT_RTNL();
106 	return ovs_lookup_vport(dp, port_no);
107 }
108 
109 /**
110  * struct ovs_skb_cb - OVS data in skb CB
111  * @flow: The flow associated with this packet.  May be %NULL if no flow.
112  */
113 struct ovs_skb_cb {
114 	struct sw_flow		*flow;
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  * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
122  * @userdata: If nonnull, its u64 value is extracted and passed to userspace as
123  * %OVS_PACKET_ATTR_USERDATA.
124  * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
125  * packet is sent and the packet is accounted in the datapath's @n_lost
126  * counter.
127  */
128 struct dp_upcall_info {
129 	u8 cmd;
130 	const struct sw_flow_key *key;
131 	const struct nlattr *userdata;
132 	u32 portid;
133 };
134 
135 static inline struct net *ovs_dp_get_net(struct datapath *dp)
136 {
137 	return read_pnet(&dp->net);
138 }
139 
140 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
141 {
142 	write_pnet(&dp->net, net);
143 }
144 
145 extern struct notifier_block ovs_dp_device_notifier;
146 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
147 
148 void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
149 void ovs_dp_detach_port(struct vport *);
150 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
151 		  const struct dp_upcall_info *);
152 
153 const char *ovs_dp_name(const struct datapath *dp);
154 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
155 					 u8 cmd);
156 
157 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb);
158 #endif /* datapath.h */
159