1 /*
2  * Copyright (c) 2007-2011 Nicira Networks.
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 
31 struct vport;
32 
33 #define DP_MAX_PORTS 1024
34 #define SAMPLE_ACTION_DEPTH 3
35 
36 /**
37  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
38  * datapath.
39  * @n_hit: Number of received packets for which a matching flow was found in
40  * the flow table.
41  * @n_miss: Number of received packets that had no matching flow in the flow
42  * table.  The sum of @n_hit and @n_miss is the number of packets that have
43  * been received by the datapath.
44  * @n_lost: Number of received packets that had no matching flow in the flow
45  * table that could not be sent to userspace (normally due to an overflow in
46  * one of the datapath's queues).
47  */
48 struct dp_stats_percpu {
49 	u64 n_hit;
50 	u64 n_missed;
51 	u64 n_lost;
52 	struct u64_stats_sync sync;
53 };
54 
55 /**
56  * struct datapath - datapath for flow-based packet switching
57  * @rcu: RCU callback head for deferred destruction.
58  * @list_node: Element in global 'dps' list.
59  * @n_flows: Number of flows currently in flow table.
60  * @table: Current flow table.  Protected by genl_lock and RCU.
61  * @ports: Map from port number to &struct vport.  %OVSP_LOCAL port
62  * always exists, other ports may be %NULL.  Protected by RTNL and RCU.
63  * @port_list: List of all ports in @ports in arbitrary order.  RTNL required
64  * to iterate or modify.
65  * @stats_percpu: Per-CPU datapath statistics.
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 vport __rcu *ports[DP_MAX_PORTS];
79 	struct list_head port_list;
80 
81 	/* Stats. */
82 	struct dp_stats_percpu __percpu *stats_percpu;
83 };
84 
85 /**
86  * struct ovs_skb_cb - OVS data in skb CB
87  * @flow: The flow associated with this packet.  May be %NULL if no flow.
88  */
89 struct ovs_skb_cb {
90 	struct sw_flow		*flow;
91 };
92 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
93 
94 /**
95  * struct dp_upcall - metadata to include with a packet to send to userspace
96  * @cmd: One of %OVS_PACKET_CMD_*.
97  * @key: Becomes %OVS_PACKET_ATTR_KEY.  Must be nonnull.
98  * @userdata: If nonnull, its u64 value is extracted and passed to userspace as
99  * %OVS_PACKET_ATTR_USERDATA.
100  * @pid: Netlink PID to which packet should be sent.  If @pid is 0 then no
101  * packet is sent and the packet is accounted in the datapath's @n_lost
102  * counter.
103  */
104 struct dp_upcall_info {
105 	u8 cmd;
106 	const struct sw_flow_key *key;
107 	const struct nlattr *userdata;
108 	u32 pid;
109 };
110 
111 extern struct notifier_block ovs_dp_device_notifier;
112 extern struct genl_multicast_group ovs_dp_vport_multicast_group;
113 
114 void ovs_dp_process_received_packet(struct vport *, struct sk_buff *);
115 void ovs_dp_detach_port(struct vport *);
116 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
117 		  const struct dp_upcall_info *);
118 
119 const char *ovs_dp_name(const struct datapath *dp);
120 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
121 					 u8 cmd);
122 
123 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb);
124 #endif /* datapath.h */
125