linux/net/openvswitch/datapath.h
Eric W. Biederman 0c5c9fb551 net: Introduce possible_net_t
Having to say
> #ifdef CONFIG_NET_NS
> 	struct net *net;
> #endif

in structures is a little bit wordy and a little bit error prone.

Instead it is possible to say:
> typedef struct {
> #ifdef CONFIG_NET_NS
>       struct net *net;
> #endif
> } possible_net_t;

And then in a header say:

> 	possible_net_t net;

Which is cleaner and easier to use and easier to test, as the
possible_net_t is always there no matter what the compile options.

Further this allows read_pnet and write_pnet to be functions in all
cases which is better at catching typos.

This change adds possible_net_t, updates the definitions of read_pnet
and write_pnet, updates optional struct net * variables that
write_pnet uses on to have the type possible_net_t, and finally fixes
up the b0rked users of read_pnet and write_pnet.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-12 14:39:40 -04:00

206 lines
5.9 KiB
C

/*
* Copyright (c) 2007-2014 Nicira, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA
*/
#ifndef DATAPATH_H
#define DATAPATH_H 1
#include <asm/page.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/u64_stats_sync.h>
#include "flow.h"
#include "flow_table.h"
#include "vport.h"
#define DP_MAX_PORTS USHRT_MAX
#define DP_VPORT_HASH_BUCKETS 1024
#define SAMPLE_ACTION_DEPTH 3
/**
* struct dp_stats_percpu - per-cpu packet processing statistics for a given
* datapath.
* @n_hit: Number of received packets for which a matching flow was found in
* the flow table.
* @n_miss: Number of received packets that had no matching flow in the flow
* table. The sum of @n_hit and @n_miss is the number of packets that have
* been received by the datapath.
* @n_lost: Number of received packets that had no matching flow in the flow
* table that could not be sent to userspace (normally due to an overflow in
* one of the datapath's queues).
* @n_mask_hit: Number of masks looked up for flow match.
* @n_mask_hit / (@n_hit + @n_missed) will be the average masks looked
* up per packet.
*/
struct dp_stats_percpu {
u64 n_hit;
u64 n_missed;
u64 n_lost;
u64 n_mask_hit;
struct u64_stats_sync syncp;
};
/**
* struct datapath - datapath for flow-based packet switching
* @rcu: RCU callback head for deferred destruction.
* @list_node: Element in global 'dps' list.
* @table: flow table.
* @ports: Hash table for ports. %OVSP_LOCAL port always exists. Protected by
* ovs_mutex and RCU.
* @stats_percpu: Per-CPU datapath statistics.
* @net: Reference to net namespace.
*
* Context: See the comment on locking at the top of datapath.c for additional
* locking information.
*/
struct datapath {
struct rcu_head rcu;
struct list_head list_node;
/* Flow table. */
struct flow_table table;
/* Switch ports. */
struct hlist_head *ports;
/* Stats. */
struct dp_stats_percpu __percpu *stats_percpu;
/* Network namespace ref. */
possible_net_t net;
u32 user_features;
};
/**
* struct ovs_skb_cb - OVS data in skb CB
* @egress_tun_key: Tunnel information about this packet on egress path.
* NULL if the packet is not being tunneled.
* @input_vport: The original vport packet came in on. This value is cached
* when a packet is received by OVS.
*/
struct ovs_skb_cb {
struct ovs_tunnel_info *egress_tun_info;
struct vport *input_vport;
};
#define OVS_CB(skb) ((struct ovs_skb_cb *)(skb)->cb)
/**
* struct dp_upcall - metadata to include with a packet to send to userspace
* @cmd: One of %OVS_PACKET_CMD_*.
* @userdata: If nonnull, its variable-length value is passed to userspace as
* %OVS_PACKET_ATTR_USERDATA.
* @portid: Netlink portid to which packet should be sent. If @portid is 0
* then no packet is sent and the packet is accounted in the datapath's @n_lost
* counter.
* @egress_tun_info: If nonnull, becomes %OVS_PACKET_ATTR_EGRESS_TUN_KEY.
*/
struct dp_upcall_info {
const struct ovs_tunnel_info *egress_tun_info;
const struct nlattr *userdata;
u32 portid;
u8 cmd;
};
/**
* struct ovs_net - Per net-namespace data for ovs.
* @dps: List of datapaths to enable dumping them all out.
* Protected by genl_mutex.
*/
struct ovs_net {
struct list_head dps;
struct work_struct dp_notify_work;
struct vport_net vport_net;
};
extern int ovs_net_id;
void ovs_lock(void);
void ovs_unlock(void);
#ifdef CONFIG_LOCKDEP
int lockdep_ovsl_is_held(void);
#else
#define lockdep_ovsl_is_held() 1
#endif
#define ASSERT_OVSL() WARN_ON(!lockdep_ovsl_is_held())
#define ovsl_dereference(p) \
rcu_dereference_protected(p, lockdep_ovsl_is_held())
#define rcu_dereference_ovsl(p) \
rcu_dereference_check(p, lockdep_ovsl_is_held())
static inline struct net *ovs_dp_get_net(const struct datapath *dp)
{
return read_pnet(&dp->net);
}
static inline void ovs_dp_set_net(struct datapath *dp, struct net *net)
{
write_pnet(&dp->net, net);
}
struct vport *ovs_lookup_vport(const struct datapath *dp, u16 port_no);
static inline struct vport *ovs_vport_rcu(const struct datapath *dp, int port_no)
{
WARN_ON_ONCE(!rcu_read_lock_held());
return ovs_lookup_vport(dp, port_no);
}
static inline struct vport *ovs_vport_ovsl_rcu(const struct datapath *dp, int port_no)
{
WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_ovsl_is_held());
return ovs_lookup_vport(dp, port_no);
}
static inline struct vport *ovs_vport_ovsl(const struct datapath *dp, int port_no)
{
ASSERT_OVSL();
return ovs_lookup_vport(dp, port_no);
}
extern struct notifier_block ovs_dp_device_notifier;
extern struct genl_family dp_vport_genl_family;
void ovs_dp_process_packet(struct sk_buff *skb, struct sw_flow_key *key);
void ovs_dp_detach_port(struct vport *);
int ovs_dp_upcall(struct datapath *, struct sk_buff *,
const struct sw_flow_key *, const struct dp_upcall_info *);
const char *ovs_dp_name(const struct datapath *dp);
struct sk_buff *ovs_vport_cmd_build_info(struct vport *, u32 pid, u32 seq,
u8 cmd);
int ovs_execute_actions(struct datapath *dp, struct sk_buff *skb,
const struct sw_flow_actions *, struct sw_flow_key *);
void ovs_dp_notify_wq(struct work_struct *work);
int action_fifos_init(void);
void action_fifos_exit(void);
#define OVS_NLERR(logging_allowed, fmt, ...) \
do { \
if (logging_allowed && net_ratelimit()) \
pr_info("netlink: " fmt "\n", ##__VA_ARGS__); \
} while (0)
#endif /* datapath.h */