From f09f7ee20c867818bacf79426cf491b2749e7eff Mon Sep 17 00:00:00 2001 From: Ang Way Chuang Date: Tue, 17 Jun 2008 21:10:33 -0700 Subject: tun: Proper handling of IPv6 header in tun driver when TUN_NO_PI is set By default, tun.c running in TUN_TUN_DEV mode will set the protocol of packet to IPv4 if TUN_NO_PI is set. My program failed to work when I assumed that the driver will check the first nibble of packet, determine IP version and set the appropriate protocol. Signed-off-by: Ang Way Chuang Acked-by: Max Krasnyansky Signed-off-by: David S. Miller --- drivers/net/tun.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/net/tun.c') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 0ce07a339c7e..7ab94c825b57 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -313,6 +313,21 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, switch (tun->flags & TUN_TYPE_MASK) { case TUN_TUN_DEV: + if (tun->flags & TUN_NO_PI) { + switch (skb->data[0] & 0xf0) { + case 0x40: + pi.proto = htons(ETH_P_IP); + break; + case 0x60: + pi.proto = htons(ETH_P_IPV6); + break; + default: + tun->dev->stats.rx_dropped++; + kfree_skb(skb); + return -EINVAL; + } + } + skb_reset_mac_header(skb); skb->protocol = pi.proto; skb->dev = tun->dev; -- cgit v1.2.3-70-g09d2 From e35259a95331ae4a9146cc03ab49aad641cab957 Mon Sep 17 00:00:00 2001 From: Max Krasnyansky Date: Thu, 10 Jul 2008 16:59:11 -0700 Subject: tun: Persistent devices can get stuck in xoff state The scenario goes like this. App stops reading from tun/tap. TX queue gets full and driver does netif_stop_queue(). App closes fd and TX queue gets flushed as part of the cleanup. Next time the app opens tun/tap and starts reading from it but the xoff state is not cleared. We're stuck. Normally xoff state is cleared when netdev is brought up. But in the case of persistent devices this happens only during initial setup. The fix is trivial. If device is already up when an app opens it we clear xoff state and that gets things moving again. Signed-off-by: Max Krasnyansky Tested-by: Christian Borntraeger Signed-off-by: David S. Miller --- drivers/net/tun.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/net/tun.c') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 7ab94c825b57..b9018bfa0a97 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -602,6 +602,12 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) tun->attached = 1; get_net(dev_net(tun->dev)); + /* Make sure persistent devices do not get stuck in + * xoff state. + */ + if (netif_running(tun->dev)) + netif_wake_queue(tun->dev); + strcpy(ifr->ifr_name, tun->dev->name); return 0; -- cgit v1.2.3-70-g09d2