1 files changed, 91 insertions, 60 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index d5bb972cbc9a..055664a26f7a 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -256,6 +256,9 @@ struct tun_struct {
 	struct tun_prog __rcu *steering_prog;
 	struct tun_prog __rcu *filter_prog;
 	struct ethtool_link_ksettings link_ksettings;
+	/* init args */
+	struct file *file;
+	struct ifreq *ifr;
 };
 
 struct veth {
@@ -281,6 +284,9 @@ void *tun_ptr_to_xdp(void *ptr)
 }
 EXPORT_SYMBOL(tun_ptr_to_xdp);
 
+static void tun_flow_init(struct tun_struct *tun);
+static void tun_flow_uninit(struct tun_struct *tun);
+
 static int tun_napi_receive(struct napi_struct *napi, int budget)
 {
 	struct tun_file *tfile = container_of(napi, struct tun_file, napi);
@@ -333,6 +339,12 @@ static void tun_napi_init(struct tun_struct *tun, struct tun_file *tfile,
 	}
 }
 
+static void tun_napi_enable(struct tun_file *tfile)
+{
+	if (tfile->napi_enabled)
+		napi_enable(&tfile->napi);
+}
+
 static void tun_napi_disable(struct tun_file *tfile)
 {
 	if (tfile->napi_enabled)
@@ -704,7 +716,8 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
 	tun = rtnl_dereference(tfile->tun);
 
 	if (tun && clean) {
-		tun_napi_disable(tfile);
+		if (!tfile->detached)
+			tun_napi_disable(tfile);
 		tun_napi_del(tfile);
 	}
 
@@ -723,8 +736,10 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
 		if (clean) {
 			RCU_INIT_POINTER(tfile->tun, NULL);
 			sock_put(&tfile->sk);
-		} else
+		} else {
 			tun_disable_queue(tun, tfile);
+			tun_napi_disable(tfile);
+		}
 
 		synchronize_net();
 		tun_flow_delete_by_queue(tun, tun->numqueues + 1);
@@ -747,7 +762,6 @@ static void __tun_detach(struct tun_file *tfile, bool clean)
 		if (tun)
 			xdp_rxq_info_unreg(&tfile->xdp_rxq);
 		ptr_ring_cleanup(&tfile->tx_ring, tun_ptr_free);
-		sock_put(&tfile->sk);
 	}
 }
 
@@ -763,6 +777,9 @@ static void tun_detach(struct tun_file *tfile, bool clean)
 	if (dev)
 		netdev_state_change(dev);
 	rtnl_unlock();
+
+	if (clean)
+		sock_put(&tfile->sk);
 }
 
 static void tun_detach_all(struct net_device *dev)
@@ -797,6 +814,7 @@ static void tun_detach_all(struct net_device *dev)
 		sock_put(&tfile->sk);
 	}
 	list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {
+		tun_napi_del(tfile);
 		tun_enable_queue(tfile);
 		tun_queue_purge(tfile);
 		xdp_rxq_info_unreg(&tfile->xdp_rxq);
@@ -877,6 +895,7 @@ static int tun_attach(struct tun_struct *tun, struct file *file,
 
 	if (tfile->detached) {
 		tun_enable_queue(tfile);
+		tun_napi_enable(tfile);
 	} else {
 		sock_hold(&tfile->sk);
 		tun_napi_init(tun, tfile, napi, napi_frags);
@@ -1025,6 +1044,49 @@ static int check_filter(struct tap_filter *filter, const struct sk_buff *skb)
 
 static const struct ethtool_ops tun_ethtool_ops;
 
+static int tun_net_init(struct net_device *dev)
+{
+	struct tun_struct *tun = netdev_priv(dev);
+	struct ifreq *ifr = tun->ifr;
+	int err;
+
+	tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
+	if (!tun->pcpu_stats)
+		return -ENOMEM;
+
+	spin_lock_init(&tun->lock);
+
+	err = security_tun_dev_alloc_security(&tun->security);
+	if (err < 0) {
+		free_percpu(tun->pcpu_stats);
+		return err;
+	}
+
+	tun_flow_init(tun);
+
+	dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
+			   TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
+			   NETIF_F_HW_VLAN_STAG_TX;
+	dev->features = dev->hw_features | NETIF_F_LLTX;
+	dev->vlan_features = dev->features &
+			     ~(NETIF_F_HW_VLAN_CTAG_TX |
+			       NETIF_F_HW_VLAN_STAG_TX);
+
+	tun->flags = (tun->flags & ~TUN_FEATURES) |
+		      (ifr->ifr_flags & TUN_FEATURES);
+
+	INIT_LIST_HEAD(&tun->disabled);
+	err = tun_attach(tun, tun->file, false, ifr->ifr_flags & IFF_NAPI,
+			 ifr->ifr_flags & IFF_NAPI_FRAGS, false);
+	if (err < 0) {
+		tun_flow_uninit(tun);
+		security_tun_dev_free_security(tun->security);
+		free_percpu(tun->pcpu_stats);
+		return err;
+	}
+	return 0;
+}
+
 /* Net device detach from fd. */
 static void tun_net_uninit(struct net_device *dev)
 {
@@ -1255,6 +1317,7 @@ static int tun_xdp(struct net_device *dev, struct netdev_bpf *xdp)
 }
 
 static const struct net_device_ops tun_netdev_ops = {
+	.ndo_init		= tun_net_init,
 	.ndo_uninit		= tun_net_uninit,
 	.ndo_open		= tun_net_open,
 	.ndo_stop		= tun_net_close,
@@ -1334,6 +1397,7 @@ static int tun_xdp_tx(struct net_device *dev, struct xdp_buff *xdp)
 }
 
 static const struct net_device_ops tap_netdev_ops = {
+	.ndo_init		= tun_net_init,
 	.ndo_uninit		= tun_net_uninit,
 	.ndo_open		= tun_net_open,
 	.ndo_stop		= tun_net_close,
@@ -1373,7 +1437,7 @@ static void tun_flow_uninit(struct tun_struct *tun)
 #define MAX_MTU 65535
 
 /* Initialize net device. */
-static void tun_net_init(struct net_device *dev)
+static void tun_net_initialize(struct net_device *dev)
 {
 	struct tun_struct *tun = netdev_priv(dev);
 
@@ -1462,7 +1526,8 @@ static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile,
 	int err;
 	int i;
 
-	if (it->nr_segs > MAX_SKB_FRAGS + 1)
+	if (it->nr_segs > MAX_SKB_FRAGS + 1 ||
+	    len > (ETH_MAX_MTU - NET_SKB_PAD - NET_IP_ALIGN))
 		return ERR_PTR(-EMSGSIZE);
 
 	local_bh_disable();
@@ -1589,7 +1654,7 @@ static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile,
 	if (zerocopy)
 		return false;
 
-	if (SKB_DATA_ALIGN(len + TUN_RX_PAD) +
+	if (SKB_DATA_ALIGN(len + TUN_RX_PAD + XDP_PACKET_HEADROOM) +
 	    SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) > PAGE_SIZE)
 		return false;
 
@@ -1950,17 +2015,25 @@ drop:
 		headlen = eth_get_headlen(skb->data, skb_headlen(skb));
 
 		if (unlikely(headlen > skb_headlen(skb))) {
+			WARN_ON_ONCE(1);
+			err = -ENOMEM;
 			this_cpu_inc(tun->pcpu_stats->rx_dropped);
+napi_busy:
 			napi_free_frags(&tfile->napi);
 			rcu_read_unlock();
 			mutex_unlock(&tfile->napi_mutex);
-			WARN_ON(1);
-			return -ENOMEM;
+			return err;
 		}
 
-		local_bh_disable();
-		napi_gro_frags(&tfile->napi);
-		local_bh_enable();
+		if (likely(napi_schedule_prep(&tfile->napi))) {
+			local_bh_disable();
+			napi_gro_frags(&tfile->napi);
+			napi_complete(&tfile->napi);
+			local_bh_enable();
+		} else {
+			err = -EBUSY;
+			goto napi_busy;
+		}
 		mutex_unlock(&tfile->napi_mutex);
 	} else if (tfile->napi_enabled) {
 		struct sk_buff_head *queue = &tfile->sk.sk_write_queue;
@@ -2636,9 +2709,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 
 		if (!dev)
 			return -ENOMEM;
-		err = dev_get_valid_name(net, dev, name);
-		if (err < 0)
-			goto err_free_dev;
 
 		dev_net_set(dev, net);
 		dev->rtnl_link_ops = &tun_link_ops;
@@ -2657,41 +2727,16 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 		tun->rx_batched = 0;
 		RCU_INIT_POINTER(tun->steering_prog, NULL);
 
-		tun->pcpu_stats = netdev_alloc_pcpu_stats(struct tun_pcpu_stats);
-		if (!tun->pcpu_stats) {
-			err = -ENOMEM;
-			goto err_free_dev;
-		}
-
-		spin_lock_init(&tun->lock);
+		tun->ifr = ifr;
+		tun->file = file;
 
-		err = security_tun_dev_alloc_security(&tun->security);
-		if (err < 0)
-			goto err_free_stat;
-
-		tun_net_init(dev);
-		tun_flow_init(tun);
-
-		dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST |
-				   TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
-				   NETIF_F_HW_VLAN_STAG_TX;
-		dev->features = dev->hw_features | NETIF_F_LLTX;
-		dev->vlan_features = dev->features &
-				     ~(NETIF_F_HW_VLAN_CTAG_TX |
-				       NETIF_F_HW_VLAN_STAG_TX);
-
-		tun->flags = (tun->flags & ~TUN_FEATURES) |
-			      (ifr->ifr_flags & TUN_FEATURES);
-
-		INIT_LIST_HEAD(&tun->disabled);
-		err = tun_attach(tun, file, false, ifr->ifr_flags & IFF_NAPI,
-				 ifr->ifr_flags & IFF_NAPI_FRAGS, false);
-		if (err < 0)
-			goto err_free_flow;
+		tun_net_initialize(dev);
 
 		err = register_netdevice(tun->dev);
-		if (err < 0)
-			goto err_detach;
+		if (err < 0) {
+			free_netdev(dev);
+			return err;
+		}
 		/* free_netdev() won't check refcnt, to aovid race
 		 * with dev_put() we need publish tun after registration.
 		 */
@@ -2710,20 +2755,6 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 
 	strcpy(ifr->ifr_name, tun->dev->name);
 	return 0;
-
-err_detach:
-	tun_detach_all(dev);
-	/* register_netdevice() already called tun_free_netdev() */
-	goto err_free_dev;
-
-err_free_flow:
-	tun_flow_uninit(tun);
-	security_tun_dev_free_security(tun->security);
-err_free_stat:
-	free_percpu(tun->pcpu_stats);
-err_free_dev:
-	free_netdev(dev);
-	return err;
 }
 
 static void tun_get_iff(struct net *net, struct tun_struct *tun,