xref: /openbmc/linux/net/openvswitch/datapath.h (revision b593bce5)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (c) 2007-2014 Nicira, Inc.
4  */
5 
6 #ifndef DATAPATH_H
7 #define DATAPATH_H 1
8 
9 #include <asm/page.h>
10 #include <linux/kernel.h>
11 #include <linux/mutex.h>
12 #include <linux/netdevice.h>
13 #include <linux/skbuff.h>
14 #include <linux/u64_stats_sync.h>
15 #include <net/ip_tunnels.h>
16 
17 #include "conntrack.h"
18 #include "flow.h"
19 #include "flow_table.h"
20 #include "meter.h"
21 #include "vport-internal_dev.h"
22 
23 #define DP_MAX_PORTS           USHRT_MAX
24 #define DP_VPORT_HASH_BUCKETS  1024
25 
26 /**
27  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
28  * datapath.
29  * @n_hit: Number of received packets for which a matching flow was found in
30  * the flow table.
31  * @n_miss: Number of received packets that had no matching flow in the flow
32  * table.  The sum of @n_hit and @n_miss is the number of packets that have
33  * been received by the datapath.
34  * @n_lost: Number of received packets that had no matching flow in the flow
35  * table that could not be sent to userspace (normally due to an overflow in
36  * one of the datapath's queues).
37  * @n_mask_hit: Number of masks looked up for flow match.
38  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
39  *   up per packet.
40  */
41 struct dp_stats_percpu {
42 	u64 n_hit;
43 	u64 n_missed;
44 	u64 n_lost;
45 	u64 n_mask_hit;
46 	struct u64_stats_sync syncp;
47 };
48 
49 /**
50  * struct datapath - datapath for flow-based packet switching
51  * @rcu: RCU callback head for deferred destruction.
52  * @list_node: Element in global 'dps' list.
53  * @table: flow table.
54  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
55  * ovs_mutex and RCU.
56  * @stats_percpu: Per-CPU datapath statistics.
57  * @net: Reference to net namespace.
58  * @max_headroom: the maximum headroom of all vports in this datapath; it will
59  * be used by all the internal vports in this dp.
60  *
61  * Context: See the comment on locking at the top of datapath.c for additional
62  * locking information.
63  */
64 struct datapath {
65 	struct rcu_head rcu;
66 	struct list_head list_node;
67 
68 	/* Flow table. */
69 	struct flow_table table;
70 
71 	/* Switch ports. */
72 	struct hlist_head *ports;
73 
74 	/* Stats. */
75 	struct dp_stats_percpu __percpu *stats_percpu;
76 
77 	/* Network namespace ref. */
78 	possible_net_t net;
79 
80 	u32 user_features;
81 
82 	u32 max_headroom;
83 
84 	/* Switch meters. */
85 	struct hlist_head *meters;
86 };
87 
88 /**
89  * struct ovs_skb_cb - OVS data in skb CB
90  * @input_vport: The original vport packet came in on. This value is cached
91  * when a packet is received by OVS.
92  * @mru: The maximum received fragement size; 0 if the packet is not
93  * fragmented.
94  * @acts_origlen: The netlink size of the flow actions applied to this skb.
95  * @cutlen: The number of bytes from the packet end to be removed.
96  */
97 struct ovs_skb_cb {
98 	struct vport		*input_vport;
99 	u16			mru;
100 	u16			acts_origlen;
101 	u32			cutlen;
102 };
103 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
104 
105 /**
106  * struct dp_upcall - metadata to include with a packet to send to userspace
107  * @cmd: One of %OVS_PACKET_CMD_*.
108  * @userdata: If nonnull, its variable-length value is passed to userspace as
109  * %OVS_PACKET_ATTR_USERDATA.
110  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
111  * then no packet is sent and the packet is accounted in the datapath's @n_lost
112  * counter.
113  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
114  * @mru: If not zero, Maximum received IP fragment size.
115  */
116 struct dp_upcall_info {
117 	struct ip_tunnel_info *egress_tun_info;
118 	const struct nlattr *userdata;
119 	const struct nlattr *actions;
120 	int actions_len;
121 	u32 portid;
122 	u8 cmd;
123 	u16 mru;
124 };
125 
126 /**
127  * struct ovs_net - Per net-namespace data for ovs.
128  * @dps: List of datapaths to enable dumping them all out.
129  * Protected by genl_mutex.
130  */
131 struct ovs_net {
132 	struct list_head dps;
133 	struct work_struct dp_notify_work;
134 #if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
135 	struct ovs_ct_limit_info *ct_limit_info;
136 #endif
137 
138 	/* Module reference for configuring conntrack. */
139 	bool xt_label;
140 };
141 
142 extern unsigned int ovs_net_id;
143 void ovs_lock(void);
144 void ovs_unlock(void);
145 
146 #ifdef CONFIG_LOCKDEP
147 int lockdep_ovsl_is_held(void);
148 #else
149 #define lockdep_ovsl_is_held()	1
150 #endif
151 
152 #define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())
153 #define ovsl_dereference(p)					\
154 	rcu_dereference_protected(p, lockdep_ovsl_is_held())
155 #define rcu_dereference_ovsl(p)					\
156 	rcu_dereference_check(p, lockdep_ovsl_is_held())
157 
158 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
159 {
160 	return read_pnet(&dp->net);
161 }
162 
163 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
164 {
165 	write_pnet(&dp->net, net);
166 }
167 
168 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
169 
170 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
171 {
172 	WARN_ON_ONCE(!rcu_read_lock_held());
173 	return ovs_lookup_vport(dp, port_no);
174 }
175 
176 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
177 {
178 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
179 	return ovs_lookup_vport(dp, port_no);
180 }
181 
182 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
183 {
184 	ASSERT_OVSL();
185 	return ovs_lookup_vport(dp, port_no);
186 }
187 
188 /* Must be called with rcu_read_lock. */
189 static inline struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
190 {
191 	struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
192 
193 	if (dev) {
194 		struct vport *vport = ovs_internal_dev_get_vport(dev);
195 
196 		if (vport)
197 			return vport->dp;
198 	}
199 
200 	return NULL;
201 }
202 
203 /* The caller must hold either ovs_mutex or rcu_read_lock to keep the
204  * returned dp pointer valid.
205  */
206 static inline struct datapath *get_dp(struct net *net, int dp_ifindex)
207 {
208 	struct datapath *dp;
209 
210 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
211 	rcu_read_lock();
212 	dp = get_dp_rcu(net, dp_ifindex);
213 	rcu_read_unlock();
214 
215 	return dp;
216 }
217 
218 extern struct notifier_block ovs_dp_device_notifier;
219 extern struct genl_family dp_vport_genl_family;
220 
221 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
222 void ovs_dp_detach_port(struct vport *);
223 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
224 		  const struct sw_flow_key *, const struct dp_upcall_info *,
225 		  uint32_t cutlen);
226 
227 const char *ovs_dp_name(const struct datapath *dp);
228 struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
229 					 u32 portid, u32 seq, u8 cmd);
230 
231 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
232 			const struct sw_flow_actions *, struct sw_flow_key *);
233 
234 void ovs_dp_notify_wq(struct work_struct *work);
235 
236 int action_fifos_init(void);
237 void action_fifos_exit(void);
238 
239 /* 'KEY' must not have any bits set outside of the 'MASK' */
240 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
241 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
242 
243 #define OVS_NLERR(logging_allowed, fmt, ...)			\
244 do {								\
245 	if (logging_allowed && net_ratelimit())			\
246 		pr_info("netlink: " fmt "\n", ##__VA_ARGS__);	\
247 } while (0)
248 #endif /* datapath.h */
249