1/*
2 * Copyright (c) 2007-2014 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 "flow_table.h"
31#include "vport.h"
32
33#define DP_MAX_PORTS           USHRT_MAX
34#define DP_VPORT_HASH_BUCKETS  1024
35
36#define SAMPLE_ACTION_DEPTH 3
37
38/**
39 * struct dp_stats_percpu - per-cpu packet processing statistics for a given
40 * datapath.
41 * @n_hit: Number of received packets for which a matching flow was found in
42 * the flow table.
43 * @n_miss: Number of received packets that had no matching flow in the flow
44 * table.  The sum of @n_hit and @n_miss is the number of packets that have
45 * been received by the datapath.
46 * @n_lost: Number of received packets that had no matching flow in the flow
47 * table that could not be sent to userspace (normally due to an overflow in
48 * one of the datapath's queues).
49 * @n_mask_hit: Number of masks looked up for flow match.
50 *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
51 *   up per packet.
52 */
53struct dp_stats_percpu {
54	u64 n_hit;
55	u64 n_missed;
56	u64 n_lost;
57	u64 n_mask_hit;
58	struct u64_stats_sync syncp;
59};
60
61/**
62 * struct datapath - datapath for flow-based packet switching
63 * @rcu: RCU callback head for deferred destruction.
64 * @list_node: Element in global 'dps' list.
65 * @table: flow table.
66 * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
67 * ovs_mutex and RCU.
68 * @stats_percpu: Per-CPU datapath statistics.
69 * @net: Reference to net namespace.
70 *
71 * Context: See the comment on locking at the top of datapath.c for additional
72 * locking information.
73 */
74struct datapath {
75	struct rcu_head rcu;
76	struct list_head list_node;
77
78	/* Flow table. */
79	struct flow_table table;
80
81	/* Switch ports. */
82	struct hlist_head *ports;
83
84	/* Stats. */
85	struct dp_stats_percpu __percpu *stats_percpu;
86
87	/* Network namespace ref. */
88	possible_net_t net;
89
90	u32 user_features;
91};
92
93/**
94 * struct ovs_skb_cb - OVS data in skb CB
95 * @egress_tun_key: Tunnel information about this packet on egress path.
96 * NULL if the packet is not being tunneled.
97 * @input_vport: The original vport packet came in on. This value is cached
98 * when a packet is received by OVS.
99 */
100struct ovs_skb_cb {
101	struct ovs_tunnel_info  *egress_tun_info;
102	struct vport		*input_vport;
103};
104#define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
105
106/**
107 * struct dp_upcall - metadata to include with a packet to send to userspace
108 * @cmd: One of %OVS_PACKET_CMD_*.
109 * @userdata: If nonnull, its variable-length value is passed to userspace as
110 * %OVS_PACKET_ATTR_USERDATA.
111 * @portid: Netlink portid to which packet should be sent.  If @portid is 0
112 * then no packet is sent and the packet is accounted in the datapath's @n_lost
113 * counter.
114 * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
115 */
116struct dp_upcall_info {
117	const struct ovs_tunnel_info *egress_tun_info;
118	const struct nlattr *userdata;
119	u32 portid;
120	u8 cmd;
121};
122
123/**
124 * struct ovs_net - Per net-namespace data for ovs.
125 * @dps: List of datapaths to enable dumping them all out.
126 * Protected by genl_mutex.
127 */
128struct ovs_net {
129	struct list_head dps;
130	struct work_struct dp_notify_work;
131	struct vport_net vport_net;
132};
133
134extern int ovs_net_id;
135void ovs_lock(void);
136void ovs_unlock(void);
137
138#ifdef CONFIG_LOCKDEP
139int lockdep_ovsl_is_held(void);
140#else
141#define lockdep_ovsl_is_held()	1
142#endif
143
144#define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())
145#define ovsl_dereference(p)					\
146	rcu_dereference_protected(p, lockdep_ovsl_is_held())
147#define rcu_dereference_ovsl(p)					\
148	rcu_dereference_check(p, lockdep_ovsl_is_held())
149
150static inline struct net *ovs_dp_get_net(const struct datapath *dp)
151{
152	return read_pnet(&dp->net);
153}
154
155static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
156{
157	write_pnet(&dp->net, net);
158}
159
160struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
161
162static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
163{
164	WARN_ON_ONCE(!rcu_read_lock_held());
165	return ovs_lookup_vport(dp, port_no);
166}
167
168static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
169{
170	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
171	return ovs_lookup_vport(dp, port_no);
172}
173
174static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
175{
176	ASSERT_OVSL();
177	return ovs_lookup_vport(dp, port_no);
178}
179
180extern struct notifier_block ovs_dp_device_notifier;
181extern struct genl_family dp_vport_genl_family;
182
183void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
184void ovs_dp_detach_port(struct vport *);
185int ovs_dp_upcall(struct datapath *, struct sk_buff *,
186		  const struct sw_flow_key *, const struct dp_upcall_info *);
187
188const char *ovs_dp_name(const struct datapath *dp);
189struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
190					 u8 cmd);
191
192int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
193			const struct sw_flow_actions *, struct sw_flow_key *);
194
195void ovs_dp_notify_wq(struct work_struct *work);
196
197int action_fifos_init(void);
198void action_fifos_exit(void);
199
200#define OVS_NLERR(logging_allowed, fmt, ...)			\
201do {								\
202	if (logging_allowed && net_ratelimit())			\
203		pr_info("netlink: " fmt "\n", ##__VA_ARGS__);	\
204} while (0)
205#endif /* datapath.h */
206