xref: /openbmc/linux/net/openvswitch/datapath.h (revision 11788d9b)
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 #define DP_MASKS_REBALANCE_INTERVAL 4000
26 
27 /**
28  * struct dp_stats_percpu - per-cpu packet processing statistics for a given
29  * datapath.
30  * @n_hit: Number of received packets for which a matching flow was found in
31  * the flow table.
32  * @n_miss: Number of received packets that had no matching flow in the flow
33  * table.  The sum of @n_hit and @n_miss is the number of packets that have
34  * been received by the datapath.
35  * @n_lost: Number of received packets that had no matching flow in the flow
36  * table that could not be sent to userspace (normally due to an overflow in
37  * one of the datapath's queues).
38  * @n_mask_hit: Number of masks looked up for flow match.
39  *   @n_mask_hit / (@n_hit + @n_missed)  will be the average masks looked
40  *   up per packet.
41  * @n_cache_hit: The number of received packets that had their mask found using
42  * the mask cache.
43  */
44 struct dp_stats_percpu {
45 	u64 n_hit;
46 	u64 n_missed;
47 	u64 n_lost;
48 	u64 n_mask_hit;
49 	u64 n_cache_hit;
50 	struct u64_stats_sync syncp;
51 };
52 
53 /**
54  * struct datapath - datapath for flow-based packet switching
55  * @rcu: RCU callback head for deferred destruction.
56  * @list_node: Element in global 'dps' list.
57  * @table: flow table.
58  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
59  * ovs_mutex and RCU.
60  * @stats_percpu: Per-CPU datapath statistics.
61  * @net: Reference to net namespace.
62  * @max_headroom: the maximum headroom of all vports in this datapath; it will
63  * be used by all the internal vports in this dp.
64  *
65  * Context: See the comment on locking at the top of datapath.c for additional
66  * locking information.
67  */
68 struct datapath {
69 	struct rcu_head rcu;
70 	struct list_head list_node;
71 
72 	/* Flow table. */
73 	struct flow_table table;
74 
75 	/* Switch ports. */
76 	struct hlist_head *ports;
77 
78 	/* Stats. */
79 	struct dp_stats_percpu __percpu *stats_percpu;
80 
81 	/* Network namespace ref. */
82 	possible_net_t net;
83 
84 	u32 user_features;
85 
86 	u32 max_headroom;
87 
88 	/* Switch meters. */
89 	struct dp_meter_table meter_tbl;
90 };
91 
92 /**
93  * struct ovs_skb_cb - OVS data in skb CB
94  * @input_vport: The original vport packet came in on. This value is cached
95  * when a packet is received by OVS.
96  * @mru: The maximum received fragement size; 0 if the packet is not
97  * fragmented.
98  * @acts_origlen: The netlink size of the flow actions applied to this skb.
99  * @cutlen: The number of bytes from the packet end to be removed.
100  */
101 struct ovs_skb_cb {
102 	struct vport		*input_vport;
103 	u16			mru;
104 	u16			acts_origlen;
105 	u32			cutlen;
106 };
107 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
108 
109 /**
110  * struct dp_upcall - metadata to include with a packet to send to userspace
111  * @cmd: One of %OVS_PACKET_CMD_*.
112  * @userdata: If nonnull, its variable-length value is passed to userspace as
113  * %OVS_PACKET_ATTR_USERDATA.
114  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
115  * then no packet is sent and the packet is accounted in the datapath's @n_lost
116  * counter.
117  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
118  * @mru: If not zero, Maximum received IP fragment size.
119  */
120 struct dp_upcall_info {
121 	struct ip_tunnel_info *egress_tun_info;
122 	const struct nlattr *userdata;
123 	const struct nlattr *actions;
124 	int actions_len;
125 	u32 portid;
126 	u8 cmd;
127 	u16 mru;
128 };
129 
130 /**
131  * struct ovs_net - Per net-namespace data for ovs.
132  * @dps: List of datapaths to enable dumping them all out.
133  * Protected by genl_mutex.
134  */
135 struct ovs_net {
136 	struct list_head dps;
137 	struct work_struct dp_notify_work;
138 	struct delayed_work masks_rebalance;
139 #if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
140 	struct ovs_ct_limit_info *ct_limit_info;
141 #endif
142 
143 	/* Module reference for configuring conntrack. */
144 	bool xt_label;
145 };
146 
147 /**
148  * enum ovs_pkt_hash_types - hash info to include with a packet
149  * to send to userspace.
150  * @OVS_PACKET_HASH_SW_BIT: indicates hash was computed in software stack.
151  * @OVS_PACKET_HASH_L4_BIT: indicates hash is a canonical 4-tuple hash
152  * over transport ports.
153  */
154 enum ovs_pkt_hash_types {
155 	OVS_PACKET_HASH_SW_BIT = (1ULL << 32),
156 	OVS_PACKET_HASH_L4_BIT = (1ULL << 33),
157 };
158 
159 extern unsigned int ovs_net_id;
160 void ovs_lock(void);
161 void ovs_unlock(void);
162 
163 #ifdef CONFIG_LOCKDEP
164 int lockdep_ovsl_is_held(void);
165 #else
166 #define lockdep_ovsl_is_held()	1
167 #endif
168 
169 #define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())
170 #define ovsl_dereference(p)					\
171 	rcu_dereference_protected(p, lockdep_ovsl_is_held())
172 #define rcu_dereference_ovsl(p)					\
173 	rcu_dereference_check(p, lockdep_ovsl_is_held())
174 
175 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
176 {
177 	return read_pnet(&dp->net);
178 }
179 
180 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
181 {
182 	write_pnet(&dp->net, net);
183 }
184 
185 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
186 
187 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
188 {
189 	WARN_ON_ONCE(!rcu_read_lock_held());
190 	return ovs_lookup_vport(dp, port_no);
191 }
192 
193 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
194 {
195 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
196 	return ovs_lookup_vport(dp, port_no);
197 }
198 
199 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
200 {
201 	ASSERT_OVSL();
202 	return ovs_lookup_vport(dp, port_no);
203 }
204 
205 /* Must be called with rcu_read_lock. */
206 static inline struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
207 {
208 	struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
209 
210 	if (dev) {
211 		struct vport *vport = ovs_internal_dev_get_vport(dev);
212 
213 		if (vport)
214 			return vport->dp;
215 	}
216 
217 	return NULL;
218 }
219 
220 /* The caller must hold either ovs_mutex or rcu_read_lock to keep the
221  * returned dp pointer valid.
222  */
223 static inline struct datapath *get_dp(struct net *net, int dp_ifindex)
224 {
225 	struct datapath *dp;
226 
227 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
228 	rcu_read_lock();
229 	dp = get_dp_rcu(net, dp_ifindex);
230 	rcu_read_unlock();
231 
232 	return dp;
233 }
234 
235 extern struct notifier_block ovs_dp_device_notifier;
236 extern struct genl_family dp_vport_genl_family;
237 
238 DECLARE_STATIC_KEY_FALSE(tc_recirc_sharing_support);
239 
240 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
241 void ovs_dp_detach_port(struct vport *);
242 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
243 		  const struct sw_flow_key *, const struct dp_upcall_info *,
244 		  uint32_t cutlen);
245 
246 const char *ovs_dp_name(const struct datapath *dp);
247 struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
248 					 u32 portid, u32 seq, u8 cmd);
249 
250 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
251 			const struct sw_flow_actions *, struct sw_flow_key *);
252 
253 void ovs_dp_notify_wq(struct work_struct *work);
254 
255 int action_fifos_init(void);
256 void action_fifos_exit(void);
257 
258 /* 'KEY' must not have any bits set outside of the 'MASK' */
259 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
260 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
261 
262 #define OVS_NLERR(logging_allowed, fmt, ...)			\
263 do {								\
264 	if (logging_allowed && net_ratelimit())			\
265 		pr_info("netlink: " fmt "\n", ##__VA_ARGS__);	\
266 } while (0)
267 #endif /* datapath.h */
268