xref: /linux/net/openvswitch/datapath.h (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
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 #include <net/ip_tunnels.h>
29 
30 #include "conntrack.h"
31 #include "flow.h"
32 #include "flow_table.h"
33 
34 #define DP_MAX_PORTS           USHRT_MAX
35 #define DP_VPORT_HASH_BUCKETS  1024
36 
37 #define SAMPLE_ACTION_DEPTH 3
38 
39 /**
40  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
41  * datapath.
42  * @n_hit: Number of received packets for which a matching flow was found in
43  * the flow table.
44  * @n_miss: Number of received packets that had no matching flow in the flow
45  * table.  The sum of @n_hit and @n_miss is the number of packets that have
46  * been received by the datapath.
47  * @n_lost: Number of received packets that had no matching flow in the flow
48  * table that could not be sent to userspace (normally due to an overflow in
49  * one of the datapath's queues).
50  * @n_mask_hit: Number of masks looked up for flow match.
51  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
52  *   up per packet.
53  */
54 struct dp_stats_percpu {
55 	u64 n_hit;
56 	u64 n_missed;
57 	u64 n_lost;
58 	u64 n_mask_hit;
59 	struct u64_stats_sync syncp;
60 };
61 
62 /**
63  * struct datapath - datapath for flow-based packet switching
64  * @rcu: RCU callback head for deferred destruction.
65  * @list_node: Element in global 'dps' list.
66  * @table: flow table.
67  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
68  * ovs_mutex and RCU.
69  * @stats_percpu: Per-CPU datapath statistics.
70  * @net: Reference to net namespace.
71  * @max_headroom: the maximum headroom of all vports in this datapath; it will
72  * be used by all the internal vports in this dp.
73  *
74  * Context: See the comment on locking at the top of datapath.c for additional
75  * locking information.
76  */
77 struct datapath {
78 	struct rcu_head rcu;
79 	struct list_head list_node;
80 
81 	/* Flow table. */
82 	struct flow_table table;
83 
84 	/* Switch ports. */
85 	struct hlist_head *ports;
86 
87 	/* Stats. */
88 	struct dp_stats_percpu __percpu *stats_percpu;
89 
90 	/* Network namespace ref. */
91 	possible_net_t net;
92 
93 	u32 user_features;
94 
95 	u32 max_headroom;
96 };
97 
98 /**
99  * struct ovs_skb_cb - OVS data in skb CB
100  * @input_vport: The original vport packet came in on. This value is cached
101  * when a packet is received by OVS.
102  * @mru: The maximum received fragement size; 0 if the packet is not
103  * @cutlen: The number of bytes from the packet end to be removed.
104  * fragmented.
105  */
106 struct ovs_skb_cb {
107 	struct vport		*input_vport;
108 	u16			mru;
109 	u32			cutlen;
110 };
111 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
112 
113 /**
114  * struct dp_upcall - metadata to include with a packet to send to userspace
115  * @cmd: One of %OVS_PACKET_CMD_*.
116  * @userdata: If nonnull, its variable-length value is passed to userspace as
117  * %OVS_PACKET_ATTR_USERDATA.
118  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
119  * then no packet is sent and the packet is accounted in the datapath's @n_lost
120  * counter.
121  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
122  * @mru: If not zero, Maximum received IP fragment size.
123  */
124 struct dp_upcall_info {
125 	struct ip_tunnel_info *egress_tun_info;
126 	const struct nlattr *userdata;
127 	const struct nlattr *actions;
128 	int actions_len;
129 	u32 portid;
130 	u8 cmd;
131 	u16 mru;
132 };
133 
134 /**
135  * struct ovs_net - Per net-namespace data for ovs.
136  * @dps: List of datapaths to enable dumping them all out.
137  * Protected by genl_mutex.
138  */
139 struct ovs_net {
140 	struct list_head dps;
141 	struct work_struct dp_notify_work;
142 
143 	/* Module reference for configuring conntrack. */
144 	bool xt_label;
145 };
146 
147 extern unsigned int ovs_net_id;
148 void ovs_lock(void);
149 void ovs_unlock(void);
150 
151 #ifdef CONFIG_LOCKDEP
152 int lockdep_ovsl_is_held(void);
153 #else
154 #define lockdep_ovsl_is_held()	1
155 #endif
156 
157 #define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())
158 #define ovsl_dereference(p)					\
159 	rcu_dereference_protected(p, lockdep_ovsl_is_held())
160 #define rcu_dereference_ovsl(p)					\
161 	rcu_dereference_check(p, lockdep_ovsl_is_held())
162 
163 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
164 {
165 	return read_pnet(&dp->net);
166 }
167 
168 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
169 {
170 	write_pnet(&dp->net, net);
171 }
172 
173 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
174 
175 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
176 {
177 	WARN_ON_ONCE(!rcu_read_lock_held());
178 	return ovs_lookup_vport(dp, port_no);
179 }
180 
181 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
182 {
183 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
184 	return ovs_lookup_vport(dp, port_no);
185 }
186 
187 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
188 {
189 	ASSERT_OVSL();
190 	return ovs_lookup_vport(dp, port_no);
191 }
192 
193 extern struct notifier_block ovs_dp_device_notifier;
194 extern struct genl_family dp_vport_genl_family;
195 
196 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
197 void ovs_dp_detach_port(struct vport *);
198 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
199 		  const struct sw_flow_key *, const struct dp_upcall_info *,
200 		  uint32_t cutlen);
201 
202 const char *ovs_dp_name(const struct datapath *dp);
203 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
204 					 u8 cmd);
205 
206 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
207 			const struct sw_flow_actions *, struct sw_flow_key *);
208 
209 void ovs_dp_notify_wq(struct work_struct *work);
210 
211 int action_fifos_init(void);
212 void action_fifos_exit(void);
213 
214 /* 'KEY' must not have any bits set outside of the 'MASK' */
215 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
216 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
217 
218 #define OVS_NLERR(logging_allowed, fmt, ...)			\
219 do {								\
220 	if (logging_allowed && net_ratelimit())			\
221 		pr_info("netlink: " fmt "\n", ##__VA_ARGS__);	\
222 } while (0)
223 #endif /* datapath.h */
224