drivers/net/tap.c

99 	.name = "tap",
146 static int tap_enable_queue(struct tap_dev *tap, struct file *file,
157 	rcu_assign_pointer(tap->taps[tap->numvtaps], q);
158 	q->queue_index = tap->numvtaps;
161 	tap->numvtaps++;
167 static int tap_set_queue(struct tap_dev *tap, struct file *file,
170 	if (tap->numqueues == MAX_TAP_QUEUES)
173 	rcu_assign_pointer(q->tap, tap);
174 	rcu_assign_pointer(tap->taps[tap->numvtaps], q);
178 	q->queue_index = tap->numvtaps;
181 	list_add_tail(&q->next, &tap->queue_list);
183 	tap->numvtaps++;
184 	tap->numqueues++;
191 	struct tap_dev *tap;
198 	tap = rtnl_dereference(q->tap);
200 	if (tap) {
202 		BUG_ON(index >= tap->numvtaps);
203 		nq = rtnl_dereference(tap->taps[tap->numvtaps - 1]);
206 		rcu_assign_pointer(tap->taps[index], nq);
207 		RCU_INIT_POINTER(tap->taps[tap->numvtaps - 1], NULL);
210 		tap->numvtaps--;
226 	struct tap_dev *tap;
229 	tap = rtnl_dereference(q->tap);
231 	if (tap) {
235 		tap->numqueues--;
236 		RCU_INIT_POINTER(q->tap, NULL);
254 static struct tap_queue *tap_get_queue(struct tap_dev *tap,
263 	int numvtaps = READ_ONCE(tap->numvtaps);
275 		queue = rcu_dereference(tap->taps[rxq % numvtaps]);
285 		queue = rcu_dereference(tap->taps[rxq]);
290 	queue = rcu_dereference(tap->taps[0]);
300 void tap_del_queues(struct tap_dev *tap)
305 	list_for_each_entry_safe(q, tmp, &tap->queue_list, next) {
307 		RCU_INIT_POINTER(q->tap, NULL);
309 			tap->numvtaps--;
310 		tap->numqueues--;
313 	BUG_ON(tap->numvtaps);
314 	BUG_ON(tap->numqueues);
316 	tap->numvtaps = MAX_TAP_QUEUES;
324 	struct tap_dev *tap;
329 	tap = tap_dev_get_rcu(dev);
330 	if (!tap)
333 	q = tap_get_queue(tap, skb);
344 		features |= tap->tap_features;
373 		/* If we receive a partial checksum and the tap side
396 	if (tap->count_rx_dropped)
397 		tap->count_rx_dropped(tap);
415 int tap_get_minor(dev_t major, struct tap_dev *tap)
428 	retval = idr_alloc(&tap_major->minor_idr, tap, 1, TAP_NUM_DEVS, GFP_ATOMIC);
430 		tap->minor = retval;
432 		netdev_err(tap->dev, "Too many tap devices\n");
443 void tap_free_minor(dev_t major, struct tap_dev *tap)
454 	if (tap->minor) {
455 		idr_remove(&tap_major->minor_idr, tap->minor);
456 		tap->minor = 0;
468 	struct tap_dev *tap;
474 		tap = NULL;
479 	tap = idr_find(&tap_major->minor_idr, minor);
480 	if (tap) {
481 		dev = tap->dev;
488 	return tap;
514 	struct tap_dev *tap;
519 	tap = dev_get_by_tap_file(imajor(inode), iminor(inode));
520 	if (!tap)
528 	if (ptr_ring_init(&q->ring, tap->dev->tx_queue_len, GFP_KERNEL)) {
545 	 * so far only KVM virtio_net uses tap, enable zero copy between
551 	if ((tap->dev->features & NETIF_F_HIGHDMA) && (tap->dev->features & NETIF_F_SG))
554 	err = tap_set_queue(tap, file, q);
560 	/* tap groks IOCB_NOWAIT just fine, mark it as such */
563 	dev_put(tap->dev);
571 	if (tap)
572 		dev_put(tap->dev);
642 	struct tap_dev *tap;
727 	tap = rcu_dereference(q->tap);
728 	if (!tap) {
733 	skb->dev = tap->dev;
769 	tap = rcu_dereference(q->tap);
770 	if (tap && tap->count_tx_dropped)
771 		tap->count_tx_dropped(tap);
916 	struct tap_dev *tap;
919 	tap = rtnl_dereference(q->tap);
920 	if (tap)
921 		dev_hold(tap->dev);
923 	return tap;
926 static void tap_put_tap_dev(struct tap_dev *tap)
928 	dev_put(tap->dev);
934 	struct tap_dev *tap;
937 	tap = tap_get_tap_dev(q);
938 	if (!tap)
942 		ret = tap_enable_queue(tap, file, q);
948 	tap_put_tap_dev(tap);
954 	struct tap_dev *tap;
958 	tap = rtnl_dereference(q->tap);
959 	if (!tap)
962 	features = tap->dev->features;
981 	/* tun/tap driver inverts the usage for TSO offloads, where
985 	 * For tap, we have to invert it to mean the same thing.
995 	/* tap_features are the same as features on tun/tap and
998 	tap->tap_features = feature_mask;
999 	if (tap->update_features)
1000 		tap->update_features(tap, features);
1006  * provide compatibility with generic tun/tap interface
1012 	struct tap_dev *tap;
1038 		tap = tap_get_tap_dev(q);
1039 		if (!tap) {
1046 		if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) ||
1049 		tap_put_tap_dev(tap);
1125 		tap = tap_get_tap_dev(q);
1126 		if (!tap) {
1131 		dev_get_mac_address(&sa, dev_net(tap->dev), tap->dev->name);
1132 		if (copy_to_user(&ifr->ifr_name, tap->dev->name, IFNAMSIZ) ||
1135 		tap_put_tap_dev(tap);
1143 		tap = tap_get_tap_dev(q);
1144 		if (!tap) {
1148 		ret = dev_set_mac_address_user(tap->dev, &sa, NULL);
1149 		tap_put_tap_dev(tap);
1176 	struct tap_dev *tap;
1208 	tap = rcu_dereference(q->tap);
1209 	if (tap) {
1210 		skb->dev = tap->dev;
1224 	tap = rcu_dereference(q->tap);
1225 	if (tap && tap->count_tx_dropped)
1226 		tap->count_tx_dropped(tap);
1313 int tap_queue_resize(struct tap_dev *tap)
1315 	struct net_device *dev = tap->dev;
1318 	int n = tap->numqueues;
1325 	list_for_each_entry(q, &tap->queue_list, next)