linux/drivers/net/macvtap.c
Greg Kroah-Hartman fa627348cf driver core: class: make namespace and get_ownership take const *
The callbacks in struct class namespace() and get_ownership() do not
modify the struct device passed to them, so mark the pointer as constant
and fix up all callbacks in the kernel to have the correct function
signature.

This helps make it more obvious what calls and callbacks do, and do not,
modify structures passed to them.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20221001165426.2690912-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09 15:49:32 +01:00

256 lines
6.3 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/etherdevice.h>
#include <linux/if_macvlan.h>
#include <linux/if_tap.h>
#include <linux/if_vlan.h>
#include <linux/interrupt.h>
#include <linux/nsproxy.h>
#include <linux/compat.h>
#include <linux/if_tun.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/cache.h>
#include <linux/sched/signal.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/wait.h>
#include <linux/cdev.h>
#include <linux/idr.h>
#include <linux/fs.h>
#include <linux/uio.h>
#include <net/net_namespace.h>
#include <net/rtnetlink.h>
#include <net/sock.h>
#include <linux/virtio_net.h>
#include <linux/skb_array.h>
struct macvtap_dev {
struct macvlan_dev vlan;
struct tap_dev tap;
};
/*
* Variables for dealing with macvtaps device numbers.
*/
static dev_t macvtap_major;
static const void *macvtap_net_namespace(const struct device *d)
{
const struct net_device *dev = to_net_dev(d->parent);
return dev_net(dev);
}
static struct class macvtap_class = {
.name = "macvtap",
.owner = THIS_MODULE,
.ns_type = &net_ns_type_operations,
.namespace = macvtap_net_namespace,
};
static struct cdev macvtap_cdev;
#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
NETIF_F_TSO6)
static void macvtap_count_tx_dropped(struct tap_dev *tap)
{
struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
struct macvlan_dev *vlan = &vlantap->vlan;
this_cpu_inc(vlan->pcpu_stats->tx_dropped);
}
static void macvtap_count_rx_dropped(struct tap_dev *tap)
{
struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
struct macvlan_dev *vlan = &vlantap->vlan;
macvlan_count_rx(vlan, 0, 0, 0);
}
static void macvtap_update_features(struct tap_dev *tap,
netdev_features_t features)
{
struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
struct macvlan_dev *vlan = &vlantap->vlan;
vlan->set_features = features;
netdev_update_features(vlan->dev);
}
static int macvtap_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[],
struct netlink_ext_ack *extack)
{
struct macvtap_dev *vlantap = netdev_priv(dev);
int err;
INIT_LIST_HEAD(&vlantap->tap.queue_list);
/* Since macvlan supports all offloads by default, make
* tap support all offloads also.
*/
vlantap->tap.tap_features = TUN_OFFLOADS;
/* Register callbacks for rx/tx drops accounting and updating
* net_device features
*/
vlantap->tap.count_tx_dropped = macvtap_count_tx_dropped;
vlantap->tap.count_rx_dropped = macvtap_count_rx_dropped;
vlantap->tap.update_features = macvtap_update_features;
err = netdev_rx_handler_register(dev, tap_handle_frame, &vlantap->tap);
if (err)
return err;
/* Don't put anything that may fail after macvlan_common_newlink
* because we can't undo what it does.
*/
err = macvlan_common_newlink(src_net, dev, tb, data, extack);
if (err) {
netdev_rx_handler_unregister(dev);
return err;
}
vlantap->tap.dev = vlantap->vlan.dev;
return 0;
}
static void macvtap_dellink(struct net_device *dev,
struct list_head *head)
{
struct macvtap_dev *vlantap = netdev_priv(dev);
netdev_rx_handler_unregister(dev);
tap_del_queues(&vlantap->tap);
macvlan_dellink(dev, head);
}
static void macvtap_setup(struct net_device *dev)
{
macvlan_common_setup(dev);
dev->tx_queue_len = TUN_READQ_SIZE;
}
static struct net *macvtap_link_net(const struct net_device *dev)
{
return dev_net(macvlan_dev_real_dev(dev));
}
static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
.kind = "macvtap",
.setup = macvtap_setup,
.newlink = macvtap_newlink,
.dellink = macvtap_dellink,
.get_link_net = macvtap_link_net,
.priv_size = sizeof(struct macvtap_dev),
};
static int macvtap_device_event(struct notifier_block *unused,
unsigned long event, void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct macvtap_dev *vlantap;
struct device *classdev;
dev_t devt;
int err;
char tap_name[IFNAMSIZ];
if (dev->rtnl_link_ops != &macvtap_link_ops)
return NOTIFY_DONE;
snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
vlantap = netdev_priv(dev);
switch (event) {
case NETDEV_REGISTER:
/* Create the device node here after the network device has
* been registered but before register_netdevice has
* finished running.
*/
err = tap_get_minor(macvtap_major, &vlantap->tap);
if (err)
return notifier_from_errno(err);
devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
classdev = device_create(&macvtap_class, &dev->dev, devt,
dev, "%s", tap_name);
if (IS_ERR(classdev)) {
tap_free_minor(macvtap_major, &vlantap->tap);
return notifier_from_errno(PTR_ERR(classdev));
}
err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
tap_name);
if (err)
return notifier_from_errno(err);
break;
case NETDEV_UNREGISTER:
/* vlan->minor == 0 if NETDEV_REGISTER above failed */
if (vlantap->tap.minor == 0)
break;
sysfs_remove_link(&dev->dev.kobj, tap_name);
devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
device_destroy(&macvtap_class, devt);
tap_free_minor(macvtap_major, &vlantap->tap);
break;
case NETDEV_CHANGE_TX_QUEUE_LEN:
if (tap_queue_resize(&vlantap->tap))
return NOTIFY_BAD;
break;
}
return NOTIFY_DONE;
}
static struct notifier_block macvtap_notifier_block __read_mostly = {
.notifier_call = macvtap_device_event,
};
static int __init macvtap_init(void)
{
int err;
err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap",
THIS_MODULE);
if (err)
goto out1;
err = class_register(&macvtap_class);
if (err)
goto out2;
err = register_netdevice_notifier(&macvtap_notifier_block);
if (err)
goto out3;
err = macvlan_link_register(&macvtap_link_ops);
if (err)
goto out4;
return 0;
out4:
unregister_netdevice_notifier(&macvtap_notifier_block);
out3:
class_unregister(&macvtap_class);
out2:
tap_destroy_cdev(macvtap_major, &macvtap_cdev);
out1:
return err;
}
module_init(macvtap_init);
static void __exit macvtap_exit(void)
{
rtnl_link_unregister(&macvtap_link_ops);
unregister_netdevice_notifier(&macvtap_notifier_block);
class_unregister(&macvtap_class);
tap_destroy_cdev(macvtap_major, &macvtap_cdev);
}
module_exit(macvtap_exit);
MODULE_ALIAS_RTNL_LINK("macvtap");
MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
MODULE_LICENSE("GPL");