drivers/net/ipvlan/ipvtap.c

   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
  30 static dev_t ipvtap_major;
  31 static struct cdev ipvtap_cdev;
  32
  33 static 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
  39 static 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
  46 struct ipvtap_dev {
  47         struct ipvl_dev vlan;
  48         struct tap_dev    tap;
  49 };
  50
  51 static 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
  59 static 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
  67 static 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
  77 static 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
 112 static 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
 122 static 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
 129 static 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
 137 static 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
 193 static struct notifier_block ipvtap_notifier_block __read_mostly = {
 194         .notifier_call  = ipvtap_device_event,
 195 };
 196
 197 static 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
 220 out4:
 221         unregister_netdevice_notifier(&ipvtap_notifier_block);
 222 out3:
 223         class_unregister(&ipvtap_class);
 224 out2:
 225         tap_destroy_cdev(ipvtap_major, &ipvtap_cdev);
 226 out1:
 227         return err;
 228 }
 229 module_init(ipvtap_init);
 230
 231 static 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 }
 238 module_exit(ipvtap_exit);
 239 MODULE_ALIAS_RTNL_LINK("ipvtap");
 240 MODULE_AUTHOR("Sainath Grandhi <sainath.grandhi@intel.com>");
 241 MODULE_LICENSE("GPL");