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 */
 54struct 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 */
 77struct 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 * @cutlen: The number of bytes from the packet end to be removed.
104 * fragmented.
105 */
106struct ovs_skb_cb {
107	struct vport		*input_vport;
108	u16			mru;
109	u32			cutlen;
110};
111#define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
112
113/**
114 * struct dp_upcall - metadata to include with a packet to send to userspace
115 * @cmd: One of %OVS_PACKET_CMD_*.
116 * @userdata: If nonnull, its variable-length value is passed to userspace as
117 * %OVS_PACKET_ATTR_USERDATA.
118 * @portid: Netlink portid to which packet should be sent.  If @portid is 0
119 * then no packet is sent and the packet is accounted in the datapath's @n_lost
120 * counter.
121 * @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
122 * @mru: If not zero, Maximum received IP fragment size.
123 */
124struct dp_upcall_info {
125	struct ip_tunnel_info *egress_tun_info;
126	const struct nlattr *userdata;
127	const struct nlattr *actions;
128	int actions_len;
129	u32 portid;
130	u8 cmd;
131	u16 mru;
132};
133
134/**
135 * struct ovs_net - Per net-namespace data for ovs.
136 * @dps: List of datapaths to enable dumping them all out.
137 * Protected by genl_mutex.
138 */
139struct ovs_net {
140	struct list_head dps;
141	struct work_struct dp_notify_work;
142
143	/* Module reference for configuring conntrack. */
144	bool xt_label;
145};
146
147extern unsigned int ovs_net_id;
148void ovs_lock(void);
149void ovs_unlock(void);
150
151#ifdef CONFIG_LOCKDEP
152int lockdep_ovsl_is_held(void);
153#else
154#define lockdep_ovsl_is_held()	1
155#endif
156
157#define ASSERT_OVSL()		WARN_ON(!lockdep_ovsl_is_held())
158#define ovsl_dereference(p)					\
159	rcu_dereference_protected(p, lockdep_ovsl_is_held())
160#define rcu_dereference_ovsl(p)					\
161	rcu_dereference_check(p, lockdep_ovsl_is_held())
162
163static inline struct net *ovs_dp_get_net(const struct datapath *dp)
164{
165	return read_pnet(&dp->net);
166}
167
168static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
169{
170	write_pnet(&dp->net, net);
171}
172
173struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
174
175static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
176{
177	WARN_ON_ONCE(!rcu_read_lock_held());
178	return ovs_lookup_vport(dp, port_no);
179}
180
181static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
182{
183	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
184	return ovs_lookup_vport(dp, port_no);
185}
186
187static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
188{
189	ASSERT_OVSL();
190	return ovs_lookup_vport(dp, port_no);
191}
192
193extern struct notifier_block ovs_dp_device_notifier;
194extern struct genl_family dp_vport_genl_family;
195
196void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
197void ovs_dp_detach_port(struct vport *);
198int ovs_dp_upcall(struct datapath *, struct sk_buff *,
199		  const struct sw_flow_key *, const struct dp_upcall_info *,
200		  uint32_t cutlen);
201
202const char *ovs_dp_name(const struct datapath *dp);
203struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
204					 u8 cmd);
205
206int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
207			const struct sw_flow_actions *, struct sw_flow_key *);
208
209void ovs_dp_notify_wq(struct work_struct *work);
210
211int action_fifos_init(void);
212void action_fifos_exit(void);
213
214/* 'KEY' must not have any bits set outside of the 'MASK' */
215#define OVS_MASKED(OLD, KEY, MASK) ((KEY) | ((OLD) & ~(MASK)))
216#define OVS_SET_MASKED(OLD, KEY, MASK) ((OLD) = OVS_MASKED(OLD, KEY, MASK))
217
218#define OVS_NLERR(logging_allowed, fmt, ...)			\
219do {								\
220	if (logging_allowed && net_ratelimit())			\
221		pr_info("netlink: " fmt "\n", ##__VA_ARGS__);	\
222} while (0)
223#endif /* datapath.h */