xref: /linux/net/openvswitch/datapath.h (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
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  */
53 struct 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  */
74 struct 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 #ifdef CONFIG_NET_NS
88 	/* Network namespace ref. */
89 	struct net *net;
90 #endif
91 
92 	u32 user_features;
93 };
94 
95 /**
96  * struct ovs_skb_cb - OVS data in skb CB
97  * @egress_tun_key: Tunnel information about this packet on egress path.
98  * NULL if the packet is not being tunneled.
99  * @input_vport: The original vport packet came in on. This value is cached
100  * when a packet is received by OVS.
101  */
102 struct ovs_skb_cb {
103 	struct ovs_tunnel_info  *egress_tun_info;
104 	struct vport		*input_vport;
105 };
106 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
107 
108 /**
109  * struct dp_upcall - metadata to include with a packet to send to userspace
110  * @cmd: One of %OVS_PACKET_CMD_*.
111  * @userdata: If nonnull, its variable-length value is passed to userspace as
112  * %OVS_PACKET_ATTR_USERDATA.
113  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
114  * then no packet is sent and the packet is accounted in the datapath's @n_lost
115  * counter.
116  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
117  */
118 struct dp_upcall_info {
119 	const struct ovs_tunnel_info *egress_tun_info;
120 	const struct nlattr *userdata;
121 	u32 portid;
122 	u8 cmd;
123 };
124 
125 /**
126  * struct ovs_net - Per net-namespace data for ovs.
127  * @dps: List of datapaths to enable dumping them all out.
128  * Protected by genl_mutex.
129  */
130 struct ovs_net {
131 	struct list_head dps;
132 	struct work_struct dp_notify_work;
133 	struct vport_net vport_net;
134 };
135 
136 extern int ovs_net_id;
137 void ovs_lock(void);
138 void ovs_unlock(void);
139 
140 #ifdef CONFIG_LOCKDEP
141 int lockdep_ovsl_is_held(void);
142 #else
143 #define lockdep_ovsl_is_held()	1
144 #endif
145 
146 #define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())
147 #define ovsl_dereference(p)					\
148 	rcu_dereference_protected(p, lockdep_ovsl_is_held())
149 #define rcu_dereference_ovsl(p)					\
150 	rcu_dereference_check(p, lockdep_ovsl_is_held())
151 
152 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
153 {
154 	return read_pnet(&dp->net);
155 }
156 
157 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
158 {
159 	write_pnet(&dp->net, net);
160 }
161 
162 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
163 
164 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
165 {
166 	WARN_ON_ONCE(!rcu_read_lock_held());
167 	return ovs_lookup_vport(dp, port_no);
168 }
169 
170 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
171 {
172 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
173 	return ovs_lookup_vport(dp, port_no);
174 }
175 
176 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
177 {
178 	ASSERT_OVSL();
179 	return ovs_lookup_vport(dp, port_no);
180 }
181 
182 extern struct notifier_block ovs_dp_device_notifier;
183 extern struct genl_family dp_vport_genl_family;
184 
185 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
186 void ovs_dp_detach_port(struct vport *);
187 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
188 		  const struct sw_flow_key *, const struct dp_upcall_info *);
189 
190 const char *ovs_dp_name(const struct datapath *dp);
191 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
192 					 u8 cmd);
193 
194 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
195 			const struct sw_flow_actions *, struct sw_flow_key *);
196 
197 void ovs_dp_notify_wq(struct work_struct *work);
198 
199 int action_fifos_init(void);
200 void action_fifos_exit(void);
201 
202 #define OVS_NLERR(logging_allowed, fmt, ...)			\
203 do {								\
204 	if (logging_allowed && net_ratelimit())			\
205 		pr_info("netlink: " fmt "\n", ##__VA_ARGS__);	\
206 } while (0)
207 #endif /* datapath.h */
208