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 * @acts_origlen: The netlink size of the flow actions applied to this skb.
104 * @cutlen: The number of bytes from the packet end to be removed.
105 * fragmented.
106 */
107 struct ovs_skb_cb {
108 struct vport *input_vport;
109 u16 mru;
110 u16 acts_origlen;
111 u32 cutlen;
112 };
113 #define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
114
115 /**
116 * struct dp_upcall - metadata to include with a packet to send to userspace
117 * @cmd: One of %OVS_PACKET_CMD_*.
118 * @userdata: If nonnull, its variable-length value is passed to userspace as
119 * %OVS_PACKET_ATTR_USERDATA.
120 * @portid: Netlink portid to which packet should be sent. If @portid is 0
121 * then no packet is sent and the packet is accounted in the datapath's @n_lost
122 * counter.
123 * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
124 * @mru: If not zero, Maximum received IP fragment size.
125 */
126 struct dp_upcall_info {
127 struct ip_tunnel_info *egress_tun_info;
128 const struct nlattr *userdata;
129 const struct nlattr *actions;
130 int actions_len;
131 u32 portid;
132 u8 cmd;
133 u16 mru;
134 };
135
136 /**
137 * struct ovs_net - Per net-namespace data for ovs.
138 * @dps: List of datapaths to enable dumping them all out.
139 * Protected by genl_mutex.
140 */
141 struct ovs_net {
142 struct list_head dps;
143 struct work_struct dp_notify_work;
144
145 /* Module reference for configuring conntrack. */
146 bool xt_label;
147 };
148
149 extern int ovs_net_id;
150 void ovs_lock(void);
151 void ovs_unlock(void);
152
153 #ifdef CONFIG_LOCKDEP
154 int lockdep_ovsl_is_held(void);
155 #else
156 #define lockdep_ovsl_is_held() 1
157 #endif
158
159 #define ASSERT_OVSL() WARN_ON(!lockdep_ovsl_is_held())
160 #define ovsl_dereference(p) \
161 rcu_dereference_protected(p, lockdep_ovsl_is_held())
162 #define rcu_dereference_ovsl(p) \
163 rcu_dereference_check(p, lockdep_ovsl_is_held())
164
ovs_dp_get_net(const struct datapath * dp)165 static inline struct net *ovs_dp_get_net(const struct datapath *dp)
166 {
167 return read_pnet(&dp->net);
168 }
169
ovs_dp_set_net(struct datapath * dp,struct net * net)170 static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
171 {
172 write_pnet(&dp->net, net);
173 }
174
175 struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
176
ovs_vport_rcu(const struct datapath * dp,int port_no)177 static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
178 {
179 WARN_ON_ONCE(!rcu_read_lock_held());
180 return ovs_lookup_vport(dp, port_no);
181 }
182
ovs_vport_ovsl_rcu(const struct datapath * dp,int port_no)183 static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
184 {
185 WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
186 return ovs_lookup_vport(dp, port_no);
187 }
188
ovs_vport_ovsl(const struct datapath * dp,int port_no)189 static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
190 {
191 ASSERT_OVSL();
192 return ovs_lookup_vport(dp, port_no);
193 }
194
195 extern struct notifier_block ovs_dp_device_notifier;
196 extern struct genl_family dp_vport_genl_family;
197
198 void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
199 void ovs_dp_detach_port(struct vport *);
200 int ovs_dp_upcall(struct datapath *, struct sk_buff *,
201 const struct sw_flow_key *, const struct dp_upcall_info *,
202 uint32_t cutlen);
203
204 const char *ovs_dp_name(const struct datapath *dp);
205 struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
206 u8 cmd);
207
208 int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
209 const struct sw_flow_actions *, struct sw_flow_key *);
210
211 void ovs_dp_notify_wq(struct work_struct *work);
212
213 int action_fifos_init(void);
214 void action_fifos_exit(void);
215
216 /* 'KEY' must not have any bits set outside of the 'MASK' */
217 #define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
218 #define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
219
220 #define OVS_NLERR(logging_allowed, fmt, ...) \
221 do { \
222 if (logging_allowed && net_ratelimit()) \
223 pr_info("netlink: " fmt "\n", ##__VA_ARGS__); \
224 } while (0)
225 #endif /* datapath.h */
226