linux/drivers/net/ipvlan/ipvtap.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2#include <linux/etherdevice.h>
   3#include "ipvlan.h"
   4#include <linux/if_vlan.h>
   5#include <linux/if_tap.h>
   6#include <linux/interrupt.h>
   7#include <linux/nsproxy.h>
   8#include <linux/compat.h>
   9#include <linux/if_tun.h>
  10#include <linux/module.h>
  11#include <linux/skbuff.h>
  12#include <linux/cache.h>
  13#include <linux/sched.h>
  14#include <linux/types.h>
  15#include <linux/slab.h>
  16#include <linux/wait.h>
  17#include <linux/cdev.h>
  18#include <linux/idr.h>
  19#include <linux/fs.h>
  20#include <linux/uio.h>
  21
  22#include <net/net_namespace.h>
  23#include <net/rtnetlink.h>
  24#include <net/sock.h>
  25#include <linux/virtio_net.h>
  26
  27#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
  28                      NETIF_F_TSO6)
  29
  30static dev_t ipvtap_major;
  31static struct cdev ipvtap_cdev;
  32
  33static const void *ipvtap_net_namespace(struct device *d)
  34{
  35        struct net_device *dev = to_net_dev(d->parent);
  36        return dev_net(dev);
  37}
  38
  39static struct class ipvtap_class = {
  40         .name = "ipvtap",
  41         .owner = THIS_MODULE,
  42         .ns_type = &net_ns_type_operations,
  43         .namespace = ipvtap_net_namespace,
  44};
  45
  46struct ipvtap_dev {
  47        struct ipvl_dev vlan;
  48        struct tap_dev    tap;
  49};
  50
  51static void ipvtap_count_tx_dropped(struct tap_dev *tap)
  52{
  53        struct ipvtap_dev *vlantap = container_of(tap, struct ipvtap_dev, tap);
  54        struct ipvl_dev *vlan = &vlantap->vlan;
  55
  56        this_cpu_inc(vlan->pcpu_stats->tx_drps);
  57}
  58
  59static void ipvtap_count_rx_dropped(struct tap_dev *tap)
  60{
  61        struct ipvtap_dev *vlantap = container_of(tap, struct ipvtap_dev, tap);
  62        struct ipvl_dev *vlan = &vlantap->vlan;
  63
  64        ipvlan_count_rx(vlan, 0, 0, 0);
  65}
  66
  67static void ipvtap_update_features(struct tap_dev *tap,
  68                                   netdev_features_t features)
  69{
  70        struct ipvtap_dev *vlantap = container_of(tap, struct ipvtap_dev, tap);
  71        struct ipvl_dev *vlan = &vlantap->vlan;
  72
  73        vlan->sfeatures = features;
  74        netdev_update_features(vlan->dev);
  75}
  76
  77static int ipvtap_newlink(struct net *src_net, struct net_device *dev,
  78                          struct nlattr *tb[], struct nlattr *data[],
  79                          struct netlink_ext_ack *extack)
  80{
  81        struct ipvtap_dev *vlantap = netdev_priv(dev);
  82        int err;
  83
  84        INIT_LIST_HEAD(&vlantap->tap.queue_list);
  85
  86        /* Since macvlan supports all offloads by default, make
  87         * tap support all offloads also.
  88         */
  89        vlantap->tap.tap_features = TUN_OFFLOADS;
  90        vlantap->tap.count_tx_dropped = ipvtap_count_tx_dropped;
  91        vlantap->tap.update_features =  ipvtap_update_features;
  92        vlantap->tap.count_rx_dropped = ipvtap_count_rx_dropped;
  93
  94        err = netdev_rx_handler_register(dev, tap_handle_frame, &vlantap->tap);
  95        if (err)
  96                return err;
  97
  98        /* Don't put anything that may fail after macvlan_common_newlink
  99         * because we can't undo what it does.
 100         */
 101        err =  ipvlan_link_new(src_net, dev, tb, data, extack);
 102        if (err) {
 103                netdev_rx_handler_unregister(dev);
 104                return err;
 105        }
 106
 107        vlantap->tap.dev = vlantap->vlan.dev;
 108
 109        return err;
 110}
 111
 112static void ipvtap_dellink(struct net_device *dev,
 113                           struct list_head *head)
 114{
 115        struct ipvtap_dev *vlan = netdev_priv(dev);
 116
 117        netdev_rx_handler_unregister(dev);
 118        tap_del_queues(&vlan->tap);
 119        ipvlan_link_delete(dev, head);
 120}
 121
 122static void ipvtap_setup(struct net_device *dev)
 123{
 124        ipvlan_link_setup(dev);
 125        dev->tx_queue_len = TUN_READQ_SIZE;
 126        dev->priv_flags &= ~IFF_NO_QUEUE;
 127}
 128
 129static struct rtnl_link_ops ipvtap_link_ops __read_mostly = {
 130        .kind           = "ipvtap",
 131        .setup          = ipvtap_setup,
 132        .newlink        = ipvtap_newlink,
 133        .dellink        = ipvtap_dellink,
 134        .priv_size      = sizeof(struct ipvtap_dev),
 135};
 136
 137static int ipvtap_device_event(struct notifier_block *unused,
 138                               unsigned long event, void *ptr)
 139{
 140        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 141        struct ipvtap_dev *vlantap;
 142        struct device *classdev;
 143        dev_t devt;
 144        int err;
 145        char tap_name[IFNAMSIZ];
 146
 147        if (dev->rtnl_link_ops != &ipvtap_link_ops)
 148                return NOTIFY_DONE;
 149
 150        snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
 151        vlantap = netdev_priv(dev);
 152
 153        switch (event) {
 154        case NETDEV_REGISTER:
 155                /* Create the device node here after the network device has
 156                 * been registered but before register_netdevice has
 157                 * finished running.
 158                 */
 159                err = tap_get_minor(ipvtap_major, &vlantap->tap);
 160                if (err)
 161                        return notifier_from_errno(err);
 162
 163                devt = MKDEV(MAJOR(ipvtap_major), vlantap->tap.minor);
 164                classdev = device_create(&ipvtap_class, &dev->dev, devt,
 165                                         dev, tap_name);
 166                if (IS_ERR(classdev)) {
 167                        tap_free_minor(ipvtap_major, &vlantap->tap);
 168                        return notifier_from_errno(PTR_ERR(classdev));
 169                }
 170                err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
 171                                        tap_name);
 172                if (err)
 173                        return notifier_from_errno(err);
 174                break;
 175        case NETDEV_UNREGISTER:
 176                /* vlan->minor == 0 if NETDEV_REGISTER above failed */
 177                if (vlantap->tap.minor == 0)
 178                        break;
 179                sysfs_remove_link(&dev->dev.kobj, tap_name);
 180                devt = MKDEV(MAJOR(ipvtap_major), vlantap->tap.minor);
 181                device_destroy(&ipvtap_class, devt);
 182                tap_free_minor(ipvtap_major, &vlantap->tap);
 183                break;
 184        case NETDEV_CHANGE_TX_QUEUE_LEN:
 185                if (tap_queue_resize(&vlantap->tap))
 186                        return NOTIFY_BAD;
 187                break;
 188        }
 189
 190        return NOTIFY_DONE;
 191}
 192
 193static struct notifier_block ipvtap_notifier_block __read_mostly = {
 194        .notifier_call  = ipvtap_device_event,
 195};
 196
 197static int ipvtap_init(void)
 198{
 199        int err;
 200
 201        err = tap_create_cdev(&ipvtap_cdev, &ipvtap_major, "ipvtap",
 202                              THIS_MODULE);
 203        if (err)
 204                goto out1;
 205
 206        err = class_register(&ipvtap_class);
 207        if (err)
 208                goto out2;
 209
 210        err = register_netdevice_notifier(&ipvtap_notifier_block);
 211        if (err)
 212                goto out3;
 213
 214        err = ipvlan_link_register(&ipvtap_link_ops);
 215        if (err)
 216                goto out4;
 217
 218        return 0;
 219
 220out4:
 221        unregister_netdevice_notifier(&ipvtap_notifier_block);
 222out3:
 223        class_unregister(&ipvtap_class);
 224out2:
 225        tap_destroy_cdev(ipvtap_major, &ipvtap_cdev);
 226out1:
 227        return err;
 228}
 229module_init(ipvtap_init);
 230
 231static void ipvtap_exit(void)
 232{
 233        rtnl_link_unregister(&ipvtap_link_ops);
 234        unregister_netdevice_notifier(&ipvtap_notifier_block);
 235        class_unregister(&ipvtap_class);
 236        tap_destroy_cdev(ipvtap_major, &ipvtap_cdev);
 237}
 238module_exit(ipvtap_exit);
 239MODULE_ALIAS_RTNL_LINK("ipvtap");
 240MODULE_AUTHOR("Sainath Grandhi <sainath.grandhi@intel.com>");
 241MODULE_LICENSE("GPL");
 242