xref: /openbmc/linux/net/openvswitch/datapath.h (revision f7d84fa7)
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 /**
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  * @n_mask_hit: Number of masks looked up for flow match.
49  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
50  *   up per packet.
51  */
52 struct dp_stats_percpu {
53 	u64 n_hit;
54 	u64 n_missed;
55 	u64 n_lost;
56 	u64 n_mask_hit;
57 	struct u64_stats_sync syncp;
58 };
59 
60 /**
61  * struct datapath - datapath for flow-based packet switching
62  * @rcu: RCU callback head for deferred destruction.
63  * @list_node: Element in global 'dps' list.
64  * @table: flow table.
65  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
66  * ovs_mutex and RCU.
67  * @stats_percpu: Per-CPU datapath statistics.
68  * @net: Reference to net namespace.
69  * @max_headroom: the maximum headroom of all vports in this datapath; it will
70  * be used by all the internal vports in this dp.
71  *
72  * Context: See the comment on locking at the top of datapath.c for additional
73  * locking information.
74  */
75 struct datapath {
76 	struct rcu_head rcu;
77 	struct list_head list_node;
78 
79 	/* Flow table. */
80 	struct flow_table table;
81 
82 	/* Switch ports. */
83 	struct hlist_head *ports;
84 
85 	/* Stats. */
86 	struct dp_stats_percpu __percpu *stats_percpu;
87 
88 	/* Network namespace ref. */
89 	possible_net_t net;
90 
91 	u32 user_features;
92 
93 	u32 max_headroom;
94 };
95 
96 /**
97  * struct ovs_skb_cb - OVS data in skb CB
98  * @input_vport: The original vport packet came in on. This value is cached
99  * when a packet is received by OVS.
100  * @mru: The maximum received fragement size; 0 if the packet is not
101  * @cutlen: The number of bytes from the packet end to be removed.
102  * fragmented.
103  */
104 struct ovs_skb_cb {
105 	struct vport		*input_vport;
106 	u16			mru;
107 	u32			cutlen;
108 };
109 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
110 
111 /**
112  * struct dp_upcall - metadata to include with a packet to send to userspace
113  * @cmd: One of %OVS_PACKET_CMD_*.
114  * @userdata: If nonnull, its variable-length value is passed to userspace as
115  * %OVS_PACKET_ATTR_USERDATA.
116  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
117  * then no packet is sent and the packet is accounted in the datapath's @n_lost
118  * counter.
119  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
120  * @mru: If not zero, Maximum received IP fragment size.
121  */
122 struct dp_upcall_info {
123 	struct ip_tunnel_info *egress_tun_info;
124 	const struct nlattr *userdata;
125 	const struct nlattr *actions;
126 	int actions_len;
127 	u32 portid;
128 	u8 cmd;
129 	u16 mru;
130 };
131 
132 /**
133  * struct ovs_net - Per net-namespace data for ovs.
134  * @dps: List of datapaths to enable dumping them all out.
135  * Protected by genl_mutex.
136  */
137 struct ovs_net {
138 	struct list_head dps;
139 	struct work_struct dp_notify_work;
140 
141 	/* Module reference for configuring conntrack. */
142 	bool xt_label;
143 };
144 
145 extern unsigned int ovs_net_id;
146 void ovs_lock(void);
147 void ovs_unlock(void);
148 
149 #ifdef CONFIG_LOCKDEP
150 int lockdep_ovsl_is_held(void);
151 #else
152 #define lockdep_ovsl_is_held()	1
153 #endif
154 
155 #define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())
156 #define ovsl_dereference(p)					\
157 	rcu_dereference_protected(p, lockdep_ovsl_is_held())
158 #define rcu_dereference_ovsl(p)					\
159 	rcu_dereference_check(p, lockdep_ovsl_is_held())
160 
161 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
162 {
163 	return read_pnet(&dp->net);
164 }
165 
166 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
167 {
168 	write_pnet(&dp->net, net);
169 }
170 
171 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
172 
173 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
174 {
175 	WARN_ON_ONCE(!rcu_read_lock_held());
176 	return ovs_lookup_vport(dp, port_no);
177 }
178 
179 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
180 {
181 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
182 	return ovs_lookup_vport(dp, port_no);
183 }
184 
185 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
186 {
187 	ASSERT_OVSL();
188 	return ovs_lookup_vport(dp, port_no);
189 }
190 
191 extern struct notifier_block ovs_dp_device_notifier;
192 extern struct genl_family dp_vport_genl_family;
193 
194 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
195 void ovs_dp_detach_port(struct vport *);
196 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
197 		  const struct sw_flow_key *, const struct dp_upcall_info *,
198 		  uint32_t cutlen);
199 
200 const char *ovs_dp_name(const struct datapath *dp);
201 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
202 					 u8 cmd);
203 
204 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
205 			const struct sw_flow_actions *, struct sw_flow_key *);
206 
207 void ovs_dp_notify_wq(struct work_struct *work);
208 
209 int action_fifos_init(void);
210 void action_fifos_exit(void);
211 
212 /* 'KEY' must not have any bits set outside of the 'MASK' */
213 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
214 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
215 
216 #define OVS_NLERR(logging_allowed, fmt, ...)			\
217 do {								\
218 	if (logging_allowed && net_ratelimit())			\
219 		pr_info("netlink: " fmt "\n", ##__VA_ARGS__);	\
220 } while (0)
221 #endif /* datapath.h */
222