diff options
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r-- | drivers/net/tun.c | 492 |
1 files changed, 327 insertions, 165 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 0ce07a3..a82b32b 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -18,15 +18,11 @@ /* * Changes: * - * Brian Braunstein <linuxkernel@bristyle.com> 2007/03/23 - * Fixed hw address handling. Now net_device.dev_addr is kept consistent - * with tun.dev_addr when the address is set by this module. - * * Mike Kershaw <dragorn@kismetwireless.net> 2005/08/14 * Add TUNSETLINK ioctl to set the link encapsulation * * Mark Smith <markzzzsmith@yahoo.com.au> - * Use random_ether_addr() for tap MAC address. + * Use random_ether_addr() for tap MAC address. * * Harald Roelle <harald.roelle@ifi.lmu.de> 2004/04/20 * Fixes in packet dropping, queue length setting and queue wakeup. @@ -48,6 +44,7 @@ #include <linux/kernel.h> #include <linux/major.h> #include <linux/slab.h> +#include <linux/smp_lock.h> #include <linux/poll.h> #include <linux/fcntl.h> #include <linux/init.h> @@ -63,6 +60,7 @@ #include <linux/if_tun.h> #include <linux/crc32.h> #include <linux/nsproxy.h> +#include <linux/virtio_net.h> #include <net/net_namespace.h> #include <net/netns/generic.h> @@ -82,9 +80,16 @@ static int debug; #define DBG1( a... ) #endif +#define FLT_EXACT_COUNT 8 +struct tap_filter { + unsigned int count; /* Number of addrs. Zero means disabled */ + u32 mask[2]; /* Mask of the hashed addrs */ + unsigned char addr[FLT_EXACT_COUNT][ETH_ALEN]; +}; + struct tun_struct { struct list_head list; - unsigned long flags; + unsigned int flags; int attached; uid_t owner; gid_t group; @@ -93,19 +98,119 @@ struct tun_struct { struct sk_buff_head readq; struct net_device *dev; + struct fasync_struct *fasync; - struct fasync_struct *fasync; - - unsigned long if_flags; - u8 dev_addr[ETH_ALEN]; - u32 chr_filter[2]; - u32 net_filter[2]; + struct tap_filter txflt; #ifdef TUN_DEBUG int debug; #endif }; +/* TAP filterting */ +static void addr_hash_set(u32 *mask, const u8 *addr) +{ + int n = ether_crc(ETH_ALEN, addr) >> 26; + mask[n >> 5] |= (1 << (n & 31)); +} + +static unsigned int addr_hash_test(const u32 *mask, const u8 *addr) +{ + int n = ether_crc(ETH_ALEN, addr) >> 26; + return mask[n >> 5] & (1 << (n & 31)); +} + +static int update_filter(struct tap_filter *filter, void __user *arg) +{ + struct { u8 u[ETH_ALEN]; } *addr; + struct tun_filter uf; + int err, alen, n, nexact; + + if (copy_from_user(&uf, arg, sizeof(uf))) + return -EFAULT; + + if (!uf.count) { + /* Disabled */ + filter->count = 0; + return 0; + } + + alen = ETH_ALEN * uf.count; + addr = kmalloc(alen, GFP_KERNEL); + if (!addr) + return -ENOMEM; + + if (copy_from_user(addr, arg + sizeof(uf), alen)) { + err = -EFAULT; + goto done; + } + + /* The filter is updated without holding any locks. Which is + * perfectly safe. We disable it first and in the worst + * case we'll accept a few undesired packets. */ + filter->count = 0; + wmb(); + + /* Use first set of addresses as an exact filter */ + for (n = 0; n < uf.count && n < FLT_EXACT_COUNT; n++) + memcpy(filter->addr[n], addr[n].u, ETH_ALEN); + + nexact = n; + + /* The rest is hashed */ + memset(filter->mask, 0, sizeof(filter->mask)); + for (; n < uf.count; n++) + addr_hash_set(filter->mask, addr[n].u); + + /* For ALLMULTI just set the mask to all ones. + * This overrides the mask populated above. */ + if ((uf.flags & TUN_FLT_ALLMULTI)) + memset(filter->mask, ~0, sizeof(filter->mask)); + + /* Now enable the filter */ + wmb(); + filter->count = nexact; + + /* Return the number of exact filters */ + err = nexact; + +done: + kfree(addr); + return err; +} + +/* Returns: 0 - drop, !=0 - accept */ +static int run_filter(struct tap_filter *filter, const struct sk_buff *skb) +{ + /* Cannot use eth_hdr(skb) here because skb_mac_hdr() is incorrect + * at this point. */ + struct ethhdr *eh = (struct ethhdr *) skb->data; + int i; + + /* Exact match */ + for (i = 0; i < filter->count; i++) + if (!compare_ether_addr(eh->h_dest, filter->addr[i])) + return 1; + + /* Inexact match (multicast only) */ + if (is_multicast_ether_addr(eh->h_dest)) + return addr_hash_test(filter->mask, eh->h_dest); + + return 0; +} + +/* + * Checks whether the packet is accepted or not. + * Returns: 0 - drop, !=0 - accept + */ +static int check_filter(struct tap_filter *filter, const struct sk_buff *skb) +{ + if (!filter->count) + return 1; + + return run_filter(filter, skb); +} + /* Network device part of the driver */ static unsigned int tun_net_id; @@ -140,7 +245,12 @@ static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev) if (!tun->attached) goto drop; - /* Packet dropping */ + /* Drop if the filter does not like it. + * This is a noop if the filter is disabled. + * Filter can be enabled only for the TAP devices. */ + if (!check_filter(&tun->txflt, skb)) + goto drop; + if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) { if (!(tun->flags & TUN_ONE_QUEUE)) { /* Normal queueing mode. */ @@ -157,7 +267,7 @@ static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev) } } - /* Queue packet */ + /* Enqueue packet */ skb_queue_tail(&tun->readq, skb); dev->trans_start = jiffies; @@ -173,41 +283,14 @@ drop: return 0; } -/** Add the specified Ethernet address to this multicast filter. */ -static void -add_multi(u32* filter, const u8* addr) -{ - int bit_nr = ether_crc(ETH_ALEN, addr) >> 26; - filter[bit_nr >> 5] |= 1 << (bit_nr & 31); -} - -/** Remove the specified Ethernet addres from this multicast filter. */ -static void -del_multi(u32* filter, const u8* addr) -{ - int bit_nr = ether_crc(ETH_ALEN, addr) >> 26; - filter[bit_nr >> 5] &= ~(1 << (bit_nr & 31)); -} - -/** Update the list of multicast groups to which the network device belongs. - * This list is used to filter packets being sent from the character device to - * the network device. */ -static void -tun_net_mclist(struct net_device *dev) +static void tun_net_mclist(struct net_device *dev) { - struct tun_struct *tun = netdev_priv(dev); - const struct dev_mc_list *mclist; - int i; - DECLARE_MAC_BUF(mac); - DBG(KERN_DEBUG "%s: tun_net_mclist: mc_count %d\n", - dev->name, dev->mc_count); - memset(tun->chr_filter, 0, sizeof tun->chr_filter); - for (i = 0, mclist = dev->mc_list; i < dev->mc_count && mclist != NULL; - i++, mclist = mclist->next) { - add_multi(tun->net_filter, mclist->dmi_addr); - DBG(KERN_DEBUG "%s: tun_net_mclist: %s\n", - dev->name, print_mac(mac, mclist->dmi_addr)); - } + /* + * This callback is supposed to deal with mc filter in + * _rx_ path and has nothing to do with the _tx_ path. + * In rx path we always accept everything userspace gives us. + */ + return; } #define MIN_MTU 68 @@ -243,13 +326,11 @@ static void tun_net_init(struct net_device *dev) case TUN_TAP_DEV: /* Ethernet TAP Device */ - dev->set_multicast_list = tun_net_mclist; - ether_setup(dev); - dev->change_mtu = tun_net_change_mtu; + dev->change_mtu = tun_net_change_mtu; + dev->set_multicast_list = tun_net_mclist; - /* random address already created for us by tun_set_iff, use it */ - memcpy(dev->dev_addr, tun->dev_addr, min(sizeof(tun->dev_addr), sizeof(dev->dev_addr)) ); + random_ether_addr(dev->dev_addr); dev->tx_queue_len = TUN_READQ_SIZE; /* We prefer our own queue length */ break; @@ -283,6 +364,7 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) }; struct sk_buff *skb; size_t len = count, align = 0; + struct virtio_net_hdr gso = { 0 }; if (!(tun->flags & TUN_NO_PI)) { if ((len -= sizeof(pi)) > count) @@ -292,6 +374,17 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, return -EFAULT; } + if (tun->flags & TUN_VNET_HDR) { + if ((len -= sizeof(gso)) > count) + return -EINVAL; + + if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso))) + return -EFAULT; + + if (gso.hdr_len > len) + return -EINVAL; + } + if ((tun->flags & TUN_TYPE_MASK) == TUN_TAP_DEV) { align = NET_IP_ALIGN; if (unlikely(len < ETH_HLEN)) @@ -311,8 +404,33 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, return -EFAULT; } + if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + if (!skb_partial_csum_set(skb, gso.csum_start, + gso.csum_offset)) { + tun->dev->stats.rx_frame_errors++; + kfree_skb(skb); + return -EINVAL; + } + } else if (tun->flags & TUN_NOCHECKSUM) + skb->ip_summed = CHECKSUM_UNNECESSARY; + 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; @@ -322,8 +440,35 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, break; }; - if (tun->flags & TUN_NOCHECKSUM) - skb->ip_summed = CHECKSUM_UNNECESSARY; + if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) { + pr_debug("GSO!\n"); + switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { + case VIRTIO_NET_HDR_GSO_TCPV4: + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4; + break; + case VIRTIO_NET_HDR_GSO_TCPV6: + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6; + break; + default: + tun->dev->stats.rx_frame_errors++; + kfree_skb(skb); + return -EINVAL; + } + + if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN) + skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN; + + skb_shinfo(skb)->gso_size = gso.gso_size; + if (skb_shinfo(skb)->gso_size == 0) { + tun->dev->stats.rx_frame_errors++; + kfree_skb(skb); + return -EINVAL; + } + + /* Header must be checked, and gso_segs computed. */ + skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY; + skb_shinfo(skb)->gso_segs = 0; + } netif_rx_ni(skb); tun->dev->last_rx = jiffies; @@ -369,6 +514,39 @@ static __inline__ ssize_t tun_put_user(struct tun_struct *tun, total += sizeof(pi); } + if (tun->flags & TUN_VNET_HDR) { + struct virtio_net_hdr gso = { 0 }; /* no info leak */ + if ((len -= sizeof(gso)) < 0) + return -EINVAL; + + if (skb_is_gso(skb)) { + struct skb_shared_info *sinfo = skb_shinfo(skb); + + /* This is a hint as to how much should be linear. */ + gso.hdr_len = skb_headlen(skb); + gso.gso_size = sinfo->gso_size; + if (sinfo->gso_type & SKB_GSO_TCPV4) + gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4; + else if (sinfo->gso_type & SKB_GSO_TCPV6) + gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV6; + else + BUG(); + if (sinfo->gso_type & SKB_GSO_TCP_ECN) + gso.gso_type |= VIRTIO_NET_HDR_GSO_ECN; + } else + gso.gso_type = VIRTIO_NET_HDR_GSO_NONE; + + if (skb->ip_summed == CHECKSUM_PARTIAL) { + gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; + gso.csum_start = skb->csum_start - skb_headroom(skb); + gso.csum_offset = skb->csum_offset; + } /* else everything is zero */ + + if (unlikely(memcpy_toiovec(iv, (void *)&gso, sizeof(gso)))) + return -EFAULT; + total += sizeof(gso); + } + len = min_t(int, skb->len, len); skb_copy_datagram_iovec(skb, 0, iv, len); @@ -388,7 +566,6 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, DECLARE_WAITQUEUE(wait, current); struct sk_buff *skb; ssize_t len, ret = 0; - DECLARE_MAC_BUF(mac); if (!tun) return -EBADFD; @@ -401,10 +578,6 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, add_wait_queue(&tun->read_wait, &wait); while (len) { - const u8 ones[ ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff }; - u8 addr[ ETH_ALEN]; - int bit_nr; - current->state = TASK_INTERRUPTIBLE; /* Read frames from the queue */ @@ -424,36 +597,9 @@ static ssize_t tun_chr_aio_read(struct kiocb *iocb, const struct iovec *iv, } netif_wake_queue(tun->dev); - /** Decide whether to accept this packet. This code is designed to - * behave identically to an Ethernet interface. Accept the packet if - * - we are promiscuous. - * - the packet is addressed to us. - * - the packet is broadcast. - * - the packet is multicast and - * - we are multicast promiscous. - * - we belong to the multicast group. - */ - skb_copy_from_linear_data(skb, addr, min_t(size_t, sizeof addr, - skb->len)); - bit_nr = ether_crc(sizeof addr, addr) >> 26; - if ((tun->if_flags & IFF_PROMISC) || - memcmp(addr, tun->dev_addr, sizeof addr) == 0 || - memcmp(addr, ones, sizeof addr) == 0 || - (((addr[0] == 1 && addr[1] == 0 && addr[2] == 0x5e) || - (addr[0] == 0x33 && addr[1] == 0x33)) && - ((tun->if_flags & IFF_ALLMULTI) || - (tun->chr_filter[bit_nr >> 5] & (1 << (bit_nr & 31)))))) { - DBG(KERN_DEBUG "%s: tun_chr_readv: accepted: %s\n", - tun->dev->name, print_mac(mac, addr)); - ret = tun_put_user(tun, skb, (struct iovec *) iv, len); - kfree_skb(skb); - break; - } else { - DBG(KERN_DEBUG "%s: tun_chr_readv: rejected: %s\n", - tun->dev->name, print_mac(mac, addr)); - kfree_skb(skb); - continue; - } + ret = tun_put_user(tun, skb, (struct iovec *) iv, len); + kfree_skb(skb); + break; } current->state = TASK_RUNNING; @@ -549,12 +695,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) tun = netdev_priv(dev); tun->dev = dev; tun->flags = flags; - /* Be promiscuous by default to maintain previous behaviour. */ - tun->if_flags = IFF_PROMISC; - /* Generate random Ethernet address. */ - *(__be16 *)tun->dev_addr = htons(0x00FF); - get_random_bytes(tun->dev_addr + sizeof(u16), 4); - memset(tun->chr_filter, 0, sizeof tun->chr_filter); + tun->txflt.count = 0; tun_net_init(dev); @@ -583,10 +724,21 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) else tun->flags &= ~TUN_ONE_QUEUE; + if (ifr->ifr_flags & IFF_VNET_HDR) + tun->flags |= TUN_VNET_HDR; + else + tun->flags &= ~TUN_VNET_HDR; + file->private_data = tun; 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; @@ -596,12 +748,53 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) return err; } +/* This is like a cut-down ethtool ops, except done via tun fd so no + * privs required. */ +static int set_offload(struct net_device *dev, unsigned long arg) +{ + unsigned int old_features, features; + + old_features = dev->features; + /* Unset features, set them as we chew on the arg. */ + features = (old_features & ~(NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST + |NETIF_F_TSO_ECN|NETIF_F_TSO|NETIF_F_TSO6)); + + if (arg & TUN_F_CSUM) { + features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; + arg &= ~TUN_F_CSUM; + + if (arg & (TUN_F_TSO4|TUN_F_TSO6)) { + if (arg & TUN_F_TSO_ECN) { + features |= NETIF_F_TSO_ECN; + arg &= ~TUN_F_TSO_ECN; + } + if (arg & TUN_F_TSO4) + features |= NETIF_F_TSO; + if (arg & TUN_F_TSO6) + features |= NETIF_F_TSO6; + arg &= ~(TUN_F_TSO4|TUN_F_TSO6); + } + } + + /* This gives the user a way to test for new features in future by + * trying to set them. */ + if (arg) + return -EINVAL; + + dev->features = features; + if (old_features != dev->features) + netdev_features_change(dev); + + return 0; +} + static int tun_chr_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { struct tun_struct *tun = file->private_data; void __user* argp = (void __user*)arg; struct ifreq ifr; + int ret; DECLARE_MAC_BUF(mac); if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) @@ -625,6 +818,15 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file, return 0; } + if (cmd == TUNGETFEATURES) { + /* Currently this just means: "what IFF flags are valid?". + * This is needed because we never checked for invalid flags on + * TUNSETIFF. */ + return put_user(IFF_TUN | IFF_TAP | IFF_NO_PI | IFF_ONE_QUEUE | + IFF_VNET_HDR, + (unsigned int __user*)argp); + } + if (!tun) return -EBADFD; @@ -668,9 +870,6 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file, break; case TUNSETLINK: - { - int ret; - /* Only allow setting the type when the interface is down */ rtnl_lock(); if (tun->dev->flags & IFF_UP) { @@ -684,85 +883,44 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file, } rtnl_unlock(); return ret; - } #ifdef TUN_DEBUG case TUNSETDEBUG: tun->debug = arg; break; #endif + case TUNSETOFFLOAD: + rtnl_lock(); + ret = set_offload(tun->dev, arg); + rtnl_unlock(); + return ret; - case SIOCGIFFLAGS: - ifr.ifr_flags = tun->if_flags; - if (copy_to_user( argp, &ifr, sizeof ifr)) - return -EFAULT; - return 0; - - case SIOCSIFFLAGS: - /** Set the character device's interface flags. Currently only - * IFF_PROMISC and IFF_ALLMULTI are used. */ - tun->if_flags = ifr.ifr_flags; - DBG(KERN_INFO "%s: interface flags 0x%lx\n", - tun->dev->name, tun->if_flags); - return 0; + case TUNSETTXFILTER: + /* Can be set only for TAPs */ + if ((tun->flags & TUN_TYPE_MASK) != TUN_TAP_DEV) + return -EINVAL; + rtnl_lock(); + ret = update_filter(&tun->txflt, (void *) __user arg); + rtnl_unlock(); + return ret; case SIOCGIFHWADDR: - /* Note: the actual net device's address may be different */ - memcpy(ifr.ifr_hwaddr.sa_data, tun->dev_addr, - min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr)); - if (copy_to_user( argp, &ifr, sizeof ifr)) + /* Get hw addres */ + memcpy(ifr.ifr_hwaddr.sa_data, tun->dev->dev_addr, ETH_ALEN); + ifr.ifr_hwaddr.sa_family = tun->dev->type; + if (copy_to_user(argp, &ifr, sizeof ifr)) return -EFAULT; return 0; case SIOCSIFHWADDR: - { - /* try to set the actual net device's hw address */ - int ret; + /* Set hw address */ + DBG(KERN_DEBUG "%s: set hw address: %s\n", + tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data)); rtnl_lock(); ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr); rtnl_unlock(); - - if (ret == 0) { - /** Set the character device's hardware address. This is used when - * filtering packets being sent from the network device to the character - * device. */ - memcpy(tun->dev_addr, ifr.ifr_hwaddr.sa_data, - min(sizeof ifr.ifr_hwaddr.sa_data, sizeof tun->dev_addr)); - DBG(KERN_DEBUG "%s: set hardware address: %x:%x:%x:%x:%x:%x\n", - tun->dev->name, - tun->dev_addr[0], tun->dev_addr[1], tun->dev_addr[2], - tun->dev_addr[3], tun->dev_addr[4], tun->dev_addr[5]); - } - - return ret; - } - - case SIOCADDMULTI: - /** Add the specified group to the character device's multicast filter - * list. */ - rtnl_lock(); - netif_tx_lock_bh(tun->dev); - add_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data); - netif_tx_unlock_bh(tun->dev); - rtnl_unlock(); - - DBG(KERN_DEBUG "%s: add multi: %s\n", - tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data)); - return 0; - - case SIOCDELMULTI: - /** Remove the specified group from the character device's multicast - * filter list. */ - rtnl_lock(); - netif_tx_lock_bh(tun->dev); - del_multi(tun->chr_filter, ifr.ifr_hwaddr.sa_data); - netif_tx_unlock_bh(tun->dev); - rtnl_unlock(); - - DBG(KERN_DEBUG "%s: del multi: %s\n", - tun->dev->name, print_mac(mac, ifr.ifr_hwaddr.sa_data)); - return 0; + return ret; default: return -EINVAL; @@ -781,22 +939,26 @@ static int tun_chr_fasync(int fd, struct file *file, int on) DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->dev->name, on); + lock_kernel(); if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) - return ret; + goto out; if (on) { ret = __f_setown(file, task_pid(current), PIDTYPE_PID, 0); if (ret) - return ret; + goto out; tun->flags |= TUN_FASYNC; } else tun->flags &= ~TUN_FASYNC; - - return 0; + ret = 0; +out: + unlock_kernel(); + return ret; } static int tun_chr_open(struct inode *inode, struct file * file) { + cycle_kernel_lock(); DBG1(KERN_INFO "tunX: tun_chr_open\n"); file->private_data = NULL; return 0; |