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