xref: /openbmc/linux/net/openvswitch/datapath.h (revision c4e78957)
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 dp_nlsk_pids - array of netlink portids of for a datapath.
55  *                       This is used when OVS_DP_F_DISPATCH_UPCALL_PER_CPU
56  *                       is enabled and must be protected by rcu.
57  * @rcu: RCU callback head for deferred destruction.
58  * @n_pids: Size of @pids array.
59  * @pids: Array storing the Netlink socket PIDs indexed by CPU ID for packets
60  *       that miss the flow table.
61  */
62 struct dp_nlsk_pids {
63 	struct rcu_head rcu;
64 	u32 n_pids;
65 	u32 pids[];
66 };
67 
68 /**
69  * struct datapath - datapath for flow-based packet switching
70  * @rcu: RCU callback head for deferred destruction.
71  * @list_node: Element in global 'dps' list.
72  * @table: flow table.
73  * @ports: Hash table for ports.  %OVSP_LOCAL port always exists.  Protected by
74  * ovs_mutex and RCU.
75  * @stats_percpu: Per-CPU datapath statistics.
76  * @net: Reference to net namespace.
77  * @max_headroom: the maximum headroom of all vports in this datapath; it will
78  * be used by all the internal vports in this dp.
79  * @upcall_portids: RCU protected 'struct dp_nlsk_pids'.
80  *
81  * Context: See the comment on locking at the top of datapath.c for additional
82  * locking information.
83  */
84 struct datapath {
85 	struct rcu_head rcu;
86 	struct list_head list_node;
87 
88 	/* Flow table. */
89 	struct flow_table table;
90 
91 	/* Switch ports. */
92 	struct hlist_head *ports;
93 
94 	/* Stats. */
95 	struct dp_stats_percpu __percpu *stats_percpu;
96 
97 	/* Network namespace ref. */
98 	possible_net_t net;
99 
100 	u32 user_features;
101 
102 	u32 max_headroom;
103 
104 	/* Switch meters. */
105 	struct dp_meter_table meter_tbl;
106 
107 	struct dp_nlsk_pids __rcu *upcall_portids;
108 };
109 
110 /**
111  * struct ovs_skb_cb - OVS data in skb CB
112  * @input_vport: The original vport packet came in on. This value is cached
113  * when a packet is received by OVS.
114  * @mru: The maximum received fragement size; 0 if the packet is not
115  * fragmented.
116  * @acts_origlen: The netlink size of the flow actions applied to this skb.
117  * @cutlen: The number of bytes from the packet end to be removed.
118  */
119 struct ovs_skb_cb {
120 	struct vport		*input_vport;
121 	u16			mru;
122 	u16			acts_origlen;
123 	u32			cutlen;
124 };
125 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
126 
127 /**
128  * struct dp_upcall - metadata to include with a packet to send to userspace
129  * @cmd: One of %OVS_PACKET_CMD_*.
130  * @userdata: If nonnull, its variable-length value is passed to userspace as
131  * %OVS_PACKET_ATTR_USERDATA.
132  * @portid: Netlink portid to which packet should be sent.  If @portid is 0
133  * then no packet is sent and the packet is accounted in the datapath's @n_lost
134  * counter.
135  * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
136  * @mru: If not zero, Maximum received IP fragment size.
137  */
138 struct dp_upcall_info {
139 	struct ip_tunnel_info *egress_tun_info;
140 	const struct nlattr *userdata;
141 	const struct nlattr *actions;
142 	int actions_len;
143 	u32 portid;
144 	u8 cmd;
145 	u16 mru;
146 };
147 
148 /**
149  * struct ovs_net - Per net-namespace data for ovs.
150  * @dps: List of datapaths to enable dumping them all out.
151  * Protected by genl_mutex.
152  */
153 struct ovs_net {
154 	struct list_head dps;
155 	struct work_struct dp_notify_work;
156 	struct delayed_work masks_rebalance;
157 #if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
158 	struct ovs_ct_limit_info *ct_limit_info;
159 #endif
160 
161 	/* Module reference for configuring conntrack. */
162 	bool xt_label;
163 };
164 
165 /**
166  * enum ovs_pkt_hash_types - hash info to include with a packet
167  * to send to userspace.
168  * @OVS_PACKET_HASH_SW_BIT: indicates hash was computed in software stack.
169  * @OVS_PACKET_HASH_L4_BIT: indicates hash is a canonical 4-tuple hash
170  * over transport ports.
171  */
172 enum ovs_pkt_hash_types {
173 	OVS_PACKET_HASH_SW_BIT = (1ULL << 32),
174 	OVS_PACKET_HASH_L4_BIT = (1ULL << 33),
175 };
176 
177 extern unsigned int ovs_net_id;
178 void ovs_lock(void);
179 void ovs_unlock(void);
180 
181 #ifdef CONFIG_LOCKDEP
182 int lockdep_ovsl_is_held(void);
183 #else
184 #define lockdep_ovsl_is_held()	1
185 #endif
186 
187 #define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())
188 #define ovsl_dereference(p)					\
189 	rcu_dereference_protected(p, lockdep_ovsl_is_held())
190 #define rcu_dereference_ovsl(p)					\
191 	rcu_dereference_check(p, lockdep_ovsl_is_held())
192 
193 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
194 {
195 	return read_pnet(&dp->net);
196 }
197 
198 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
199 {
200 	write_pnet(&dp->net, net);
201 }
202 
203 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
204 
205 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
206 {
207 	WARN_ON_ONCE(!rcu_read_lock_held());
208 	return ovs_lookup_vport(dp, port_no);
209 }
210 
211 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
212 {
213 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
214 	return ovs_lookup_vport(dp, port_no);
215 }
216 
217 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
218 {
219 	ASSERT_OVSL();
220 	return ovs_lookup_vport(dp, port_no);
221 }
222 
223 /* Must be called with rcu_read_lock. */
224 static inline struct datapath *get_dp_rcu(struct net *net, int dp_ifindex)
225 {
226 	struct net_device *dev = dev_get_by_index_rcu(net, dp_ifindex);
227 
228 	if (dev) {
229 		struct vport *vport = ovs_internal_dev_get_vport(dev);
230 
231 		if (vport)
232 			return vport->dp;
233 	}
234 
235 	return NULL;
236 }
237 
238 /* The caller must hold either ovs_mutex or rcu_read_lock to keep the
239  * returned dp pointer valid.
240  */
241 static inline struct datapath *get_dp(struct net *net, int dp_ifindex)
242 {
243 	struct datapath *dp;
244 
245 	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
246 	rcu_read_lock();
247 	dp = get_dp_rcu(net, dp_ifindex);
248 	rcu_read_unlock();
249 
250 	return dp;
251 }
252 
253 extern struct notifier_block ovs_dp_device_notifier;
254 extern struct genl_family dp_vport_genl_family;
255 
256 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
257 void ovs_dp_detach_port(struct vport *);
258 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
259 		  const struct sw_flow_key *, const struct dp_upcall_info *,
260 		  uint32_t cutlen);
261 
262 u32 ovs_dp_get_upcall_portid(const struct datapath *dp, uint32_t cpu_id);
263 
264 const char *ovs_dp_name(const struct datapath *dp);
265 struct sk_buff *ovs_vport_cmd_build_info(struct vport *vport, struct net *net,
266 					 u32 portid, u32 seq, u8 cmd);
267 
268 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
269 			const struct sw_flow_actions *, struct sw_flow_key *);
270 
271 void ovs_dp_notify_wq(struct work_struct *work);
272 
273 int action_fifos_init(void);
274 void action_fifos_exit(void);
275 
276 /* 'KEY' must not have any bits set outside of the 'MASK' */
277 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
278 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
279 
280 #define OVS_NLERR(logging_allowed, fmt, ...)			\
281 do {								\
282 	if (logging_allowed && net_ratelimit())			\
283 		pr_info("netlink: " fmt "\n", ##__VA_ARGS__);	\
284 } while (0)
285 #endif /* datapath.h */
286