- 根目录:
- net
- openvswitch
- vport.c
/*
* Copyright (c) 2007-2011 Nicira Networks.
*
* 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
*/
#include <linux/dcache.h>
#include <linux/etherdevice.h>
#include <linux/if.h>
#include <linux/if_vlan.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/percpu.h>
#include <linux/rcupdate.h>
#include <linux/rtnetlink.h>
#include <linux/compat.h>
#include "vport.h"
#include "vport-internal_dev.h"
/* List of statically compiled vport implementations. Don't forget to also
* add yours to the list at the bottom of vport.h. */
static const struct vport_ops *vport_ops_list[] = {
&ovs_netdev_vport_ops,
&ovs_internal_vport_ops,
};
/* Protected by RCU read lock for reading, RTNL lock for writing. */
static struct hlist_head *dev_table;
#define VPORT_HASH_BUCKETS 1024
/**
* ovs_vport_init - initialize vport subsystem
*
* Called at module load time to initialize the vport subsystem.
*/
int ovs_vport_init(void)
{
dev_table = kzalloc(VPORT_HASH_BUCKETS * sizeof(struct hlist_head),
GFP_KERNEL);
if (!dev_table)
return -ENOMEM;
return 0;
}
/**
* ovs_vport_exit - shutdown vport subsystem
*
* Called at module exit time to shutdown the vport subsystem.
*/
void ovs_vport_exit(void)
{
kfree(dev_table);
}
static struct hlist_head *hash_bucket(const char *name)
{
unsigned int hash = full_name_hash(name, strlen(name));
return &dev_table[hash & (VPORT_HASH_BUCKETS - 1)];
}
/**
* ovs_vport_locate - find a port that has already been created
*
* @name: name of port to find
*
* Must be called with RTNL or RCU read lock.
*/
struct vport *ovs_vport_locate(const char *name)
{
struct hlist_head *bucket = hash_bucket(name);
struct vport *vport;
struct hlist_node *node;
hlist_for_each_entry_rcu(vport, node, bucket, hash_node)
if (!strcmp(name, vport->ops->get_name(vport)))
return vport;
return NULL;
}
/**
* ovs_vport_alloc - allocate and initialize new vport
*
* @priv_size: Size of private data area to allocate.
* @ops: vport device ops
*
* Allocate and initialize a new vport defined by @ops. The vport will contain
* a private data area of size @priv_size that can be accessed using
* vport_priv(). vports that are no longer needed should be released with
* vport_free().
*/
struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *ops,
const struct vport_parms *parms)
{
struct vport *vport;
size_t alloc_size;
alloc_size = sizeof(struct vport);
if (priv_size) {
alloc_size = ALIGN(alloc_size, VPORT_ALIGN);
alloc_size += priv_size;
}
vport = kzalloc(alloc_size, GFP_KERNEL);
if (!vport)
return ERR_PTR(-ENOMEM);
vport->dp = parms->dp;
vport->port_no = parms->port_no;
vport->upcall_pid = parms->upcall_pid;
vport->ops = ops;
vport->percpu_stats = alloc_percpu(struct vport_percpu_stats);
if (!vport->percpu_stats) {
kfree(vport);
return ERR_PTR(-ENOMEM);
}
spin_lock_init(&vport->stats_lock);
return vport;
}
/**
* ovs_vport_free - uninitialize and free vport
*
* @vport: vport to free
*
* Frees a vport allocated with vport_alloc() when it is no longer needed.
*
* The caller must ensure that an RCU grace period has passed since the last
* time @vport was in a datapath.
*/
void ovs_vport_free(struct vport *vport)
{
free_percpu(vport->percpu_stats);
kfree(vport);
}
/**
* ovs_vport_add - add vport device (for kernel callers)
*
* @parms: Information about new vport.
*
* Creates a new vport with the specified configuration (which is dependent on
* device type). RTNL lock must be held.
*/
struct vport *ovs_vport_add(const struct vport_parms *parms)
{
struct vport *vport;
int err = 0;
int i;
ASSERT_RTNL();
for (i = 0; i < ARRAY_SIZE(vport_ops_list); i++) {
if (vport_ops_list[i]->type == parms->type) {
vport = vport_ops_list[i]->create(parms);
if (IS_ERR(vport)) {
err = PTR_ERR(vport);
goto out;
}
hlist_add_head_rcu(&vport->hash_node,
hash_bucket(vport->ops->get_name(vport)));
return vport;
}
}
err = -EAFNOSUPPORT;
out:
return ERR_PTR(err);
}
/**
* ovs_vport_set_options - modify existing vport device (for kernel callers)
*
* @vport: vport to modify.
* @port: New configuration.
*
* Modifies an existing device with the specified configuration (which is
* dependent on device type). RTNL lock must be held.
*/
int ovs_vport_set_options(struct vport *vport, struct nlattr *options)
{
ASSERT_RTNL();
if (!vport->ops->set_options)
return -EOPNOTSUPP;
return vport->ops->set_options(vport, options);
}
/**
* ovs_vport_del - delete existing vport device
*
* @vport: vport to delete.
*
* Detaches @vport from its datapath and destroys it. It is possible to fail
* for reasons such as lack of memory. RTNL lock must be held.
*/
void ovs_vport_del(struct vport *vport)
{
ASSERT_RTNL();
hlist_del_rcu(&vport->hash_node);
vport->ops->destroy(vport);
}
/**
* ovs_vport_get_stats - retrieve device stats
*
* @vport: vport from which to retrieve the stats
* @stats: location to store stats
*
* Retrieves transmit, receive, and error stats for the given device.
*
* Must be called with RTNL lock or rcu_read_lock.
*/
void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
{
int i;
memset(stats, 0, sizeof(*stats));
/* We potentially have 2 sources of stats that need to be combined:
* those we have collected (split into err_stats and percpu_stats) from
* set_stats() and device error stats from netdev->get_stats() (for
* errors that happen downstream and therefore aren't reported through
* our vport_record_error() function).
* Stats from first source are reported by ovs (OVS_VPORT_ATTR_STATS).
* netdev-stats can be directly read over netlink-ioctl.
*/
spin_lock_bh(&vport->stats_lock);
stats->rx_errors = vport->err_stats.rx_errors;
stats->tx_errors = vport->err_stats.tx_errors;
stats->tx_dropped = vport->err_stats.tx_dropped;
stats->rx_dropped = vport->err_stats.rx_dropped;
spin_unlock_bh(&vport->stats_lock);
for_each_possible_cpu(i) {
const struct vport_percpu_stats *percpu_stats;
struct vport_percpu_stats local_stats;
unsigned int start;
percpu_stats = per_cpu_ptr(vport->percpu_stats, i);
do {
start = u64_stats_fetch_begin_bh(&percpu_stats->sync);
local_stats = *percpu_stats;
} while (u64_stats_fetch_retry_bh(&percpu_stats->sync, start));
stats->rx_bytes += local_stats.rx_bytes;
stats->rx_packets += local_stats.rx_packets;
stats->tx_bytes += local_stats.tx_bytes;
stats->tx_packets += local_stats.tx_packets;
}
}
/**
* ovs_vport_get_options - retrieve device options
*
* @vport: vport from which to retrieve the options.
* @skb: sk_buff where options should be appended.
*
* Retrieves the configuration of the given device, appending an
* %OVS_VPORT_ATTR_OPTIONS attribute that in turn contains nested
* vport-specific attributes to @skb.
*
* Returns 0 if successful, -EMSGSIZE if @skb has insufficient room, or another
* negative error code if a real error occurred. If an error occurs, @skb is
* left unmodified.
*
* Must be called with RTNL lock or rcu_read_lock.
*/
int ovs_vport_get_options(const struct vport *vport, struct sk_buff *skb)
{
struct nlattr *nla;
nla = nla_nest_start(skb, OVS_VPORT_ATTR_OPTIONS);
if (!nla)
return -EMSGSIZE;
if (vport->ops->get_options) {
int err = vport->ops->get_options(vport, skb);
if (err) {
nla_nest_cancel(skb, nla);
return err;
}
}
nla_nest_end(skb, nla);
return 0;
}
/**
* ovs_vport_receive - pass up received packet to the datapath for processing
*
* @vport: vport that received the packet
* @skb: skb that was received
*
* Must be called with rcu_read_lock. The packet cannot be shared and
* skb->data should point to the Ethernet header. The caller must have already
* called compute_ip_summed() to initialize the checksumming fields.
*/
void ovs_vport_receive(struct vport *vport, struct sk_buff *skb)
{
struct vport_percpu_stats *stats;
stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
u64_stats_update_begin(&stats->sync);
stats->rx_packets++;
stats->rx_bytes += skb->len;
u64_stats_update_end(&stats->sync);
ovs_dp_process_received_packet(vport, skb);
}
/**
* ovs_vport_send - send a packet on a device
*
* @vport: vport on which to send the packet
* @skb: skb to send
*
* Sends the given packet and returns the length of data sent. Either RTNL
* lock or rcu_read_lock must be held.
*/
int ovs_vport_send(struct vport *vport, struct sk_buff *skb)
{
int sent = vport->ops->send(vport, skb);
if (likely(sent)) {
struct vport_percpu_stats *stats;
stats = per_cpu_ptr(vport->percpu_stats, smp_processor_id());
u64_stats_update_begin(&stats->sync);
stats->tx_packets++;
stats->tx_bytes += sent;
u64_stats_update_end(&stats->sync);
}
return sent;
}
/**
* ovs_vport_record_error - indicate device error to generic stats layer
*
* @vport: vport that encountered the error
* @err_type: one of enum vport_err_type types to indicate the error type
*
* If using the vport generic stats layer indicate that an error of the given
* type has occured.
*/
void ovs_vport_record_error(struct vport *vport, enum vport_err_type err_type)
{
spin_lock(&vport->stats_lock);
switch (err_type) {
case VPORT_E_RX_DROPPED:
vport->err_stats.rx_dropped++;
break;
case VPORT_E_RX_ERROR:
vport->err_stats.rx_errors++;
break;
case VPORT_E_TX_DROPPED:
vport->err_stats.tx_dropped++;
break;
case VPORT_E_TX_ERROR:
vport->err_stats.tx_errors++;
break;
};
spin_unlock(&vport->stats_lock);
}