| /* |
| * TUN - Universal TUN/TAP device driver. |
| * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $ |
| */ |
| |
| /* |
| * Daniel Podlejski <underley@underley.eu.org> |
| * Modifications for 2.3.99-pre5 kernel. |
| */ |
| |
| #define TUN_VER "1.5" |
| |
| #include <linux/config.h> |
| #include <linux/module.h> |
| |
| #include <linux/errno.h> |
| #include <linux/kernel.h> |
| #include <linux/major.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/poll.h> |
| #include <linux/fcntl.h> |
| #include <linux/init.h> |
| #include <linux/random.h> |
| |
| #include <linux/skbuff.h> |
| #include <linux/netdevice.h> |
| #include <linux/etherdevice.h> |
| #include <linux/miscdevice.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/if.h> |
| #include <linux/if_arp.h> |
| #include <linux/if_ether.h> |
| #include <linux/if_tun.h> |
| |
| #include <asm/system.h> |
| #include <asm/uaccess.h> |
| |
| #ifdef TUN_DEBUG |
| static int debug; |
| #endif |
| |
| /* Network device part of the driver */ |
| |
| /* Net device open. */ |
| static int tun_net_open(struct net_device *dev) |
| { |
| netif_start_queue(dev); |
| return 0; |
| } |
| |
| /* Net device close. */ |
| static int tun_net_close(struct net_device *dev) |
| { |
| netif_stop_queue(dev); |
| return 0; |
| } |
| |
| /* Net device start xmit */ |
| static int tun_net_xmit(struct sk_buff *skb, struct net_device *dev) |
| { |
| struct tun_struct *tun = (struct tun_struct *)dev->priv; |
| |
| DBG(KERN_INFO "%s: tun_net_xmit %d\n", tun->name, skb->len); |
| |
| /* Drop packet if interface is not attached */ |
| if (!tun->attached) |
| goto drop; |
| |
| /* Queue packet */ |
| if (!(tun->flags & TUN_ONE_QUEUE)) { |
| /* Normal queueing mode. |
| * Packet scheduler handles dropping. */ |
| if (skb_queue_len(&tun->readq) >= TUN_READQ_SIZE) |
| netif_stop_queue(dev); |
| } else { |
| /* Single queue mode. |
| * Driver handles dropping itself. */ |
| if (skb_queue_len(&tun->readq) >= dev->tx_queue_len) |
| goto drop; |
| } |
| skb_queue_tail(&tun->readq, skb); |
| |
| /* Notify and wake up reader process */ |
| if (tun->flags & TUN_FASYNC) |
| kill_fasync(&tun->fasync, SIGIO, POLL_IN); |
| wake_up_interruptible(&tun->read_wait); |
| return 0; |
| |
| drop: |
| tun->stats.tx_dropped++; |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| static void tun_net_mclist(struct net_device *dev) |
| { |
| /* Nothing to do for multicast filters. |
| * We always accept all frames. */ |
| return; |
| } |
| |
| static struct net_device_stats *tun_net_stats(struct net_device *dev) |
| { |
| struct tun_struct *tun = (struct tun_struct *)dev->priv; |
| return &tun->stats; |
| } |
| |
| #define MIN_MTU 68 |
| #define MAX_MTU 65535 |
| |
| static int tun_net_change_mtu(struct net_device *dev, int new_mtu) { |
| if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU) |
| return -EINVAL; |
| dev->mtu = new_mtu; |
| return 0; |
| } |
| |
| |
| /* Initialize net device. */ |
| int tun_net_init(struct net_device *dev) |
| { |
| struct tun_struct *tun = (struct tun_struct *)dev->priv; |
| |
| DBG(KERN_INFO "%s: tun_net_init\n", tun->name); |
| |
| SET_MODULE_OWNER(dev); |
| dev->open = tun_net_open; |
| dev->hard_start_xmit = tun_net_xmit; |
| dev->stop = tun_net_close; |
| dev->get_stats = tun_net_stats; |
| |
| switch (tun->flags & TUN_TYPE_MASK) { |
| case TUN_TUN_DEV: |
| /* Point-to-Point TUN Device */ |
| dev->hard_header_len = 0; |
| dev->addr_len = 0; |
| dev->mtu = 1500; |
| |
| /* Zero header length */ |
| dev->type = ARPHRD_NONE; |
| dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; |
| dev->tx_queue_len = 10; |
| break; |
| |
| case TUN_TAP_DEV: |
| /* Ethernet TAP Device */ |
| dev->set_multicast_list = tun_net_mclist; |
| |
| /* Generate random Ethernet address. */ |
| *(u16 *)dev->dev_addr = htons(0x00FF); |
| get_random_bytes(dev->dev_addr + sizeof(u16), 4); |
| |
| ether_setup(dev); |
| break; |
| }; |
| |
| dev->change_mtu = tun_net_change_mtu; |
| return 0; |
| } |
| |
| /* Character device part */ |
| |
| /* Poll */ |
| static unsigned int tun_chr_poll(struct file *file, poll_table * wait) |
| { |
| struct tun_struct *tun = (struct tun_struct *)file->private_data; |
| unsigned int mask = POLLOUT | POLLWRNORM; |
| |
| if (!tun) |
| return -EBADFD; |
| |
| DBG(KERN_INFO "%s: tun_chr_poll\n", tun->name); |
| |
| poll_wait(file, &tun->read_wait, wait); |
| |
| if (skb_queue_len(&tun->readq)) |
| mask |= POLLIN | POLLRDNORM; |
| |
| return mask; |
| } |
| |
| /* Get packet from user space buffer(already verified) */ |
| static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count) |
| { |
| struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) }; |
| struct sk_buff *skb; |
| size_t len = count; |
| |
| if (!(tun->flags & TUN_NO_PI)) { |
| if ((len -= sizeof(pi)) > count) |
| return -EINVAL; |
| |
| memcpy_fromiovec((void *)&pi, iv, sizeof(pi)); |
| } |
| |
| if (!(skb = alloc_skb(len + 2, GFP_KERNEL))) { |
| tun->stats.rx_dropped++; |
| return -ENOMEM; |
| } |
| |
| skb_reserve(skb, 2); |
| memcpy_fromiovec(skb_put(skb, len), iv, len); |
| |
| skb->dev = &tun->dev; |
| switch (tun->flags & TUN_TYPE_MASK) { |
| case TUN_TUN_DEV: |
| skb->mac.raw = skb->data; |
| skb->protocol = pi.proto; |
| break; |
| case TUN_TAP_DEV: |
| skb->protocol = eth_type_trans(skb, &tun->dev); |
| break; |
| }; |
| |
| if (tun->flags & TUN_NOCHECKSUM) |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| |
| netif_rx_ni(skb); |
| |
| tun->stats.rx_packets++; |
| tun->stats.rx_bytes += len; |
| |
| return count; |
| } |
| |
| /* Writev */ |
| static ssize_t tun_chr_writev(struct file * file, const struct iovec *iv, |
| unsigned long count, loff_t *pos) |
| { |
| struct tun_struct *tun = (struct tun_struct *)file->private_data; |
| unsigned long i; |
| size_t len; |
| |
| if (!tun) |
| return -EBADFD; |
| |
| DBG(KERN_INFO "%s: tun_chr_write %d\n", tun->name, count); |
| |
| for (i = 0, len = 0; i < count; i++) { |
| if (verify_area(VERIFY_READ, iv[i].iov_base, iv[i].iov_len)) |
| return -EFAULT; |
| len += iv[i].iov_len; |
| } |
| |
| return tun_get_user(tun, (struct iovec *) iv, len); |
| } |
| |
| /* Write */ |
| static ssize_t tun_chr_write(struct file * file, const char * buf, |
| size_t count, loff_t *pos) |
| { |
| struct iovec iv = { (void *) buf, count }; |
| return tun_chr_writev(file, &iv, 1, pos); |
| } |
| |
| /* Put packet to the user space buffer (already verified) */ |
| static __inline__ ssize_t tun_put_user(struct tun_struct *tun, |
| struct sk_buff *skb, |
| struct iovec *iv, int len) |
| { |
| struct tun_pi pi = { 0, skb->protocol }; |
| ssize_t total = 0; |
| |
| if (!(tun->flags & TUN_NO_PI)) { |
| if ((len -= sizeof(pi)) < 0) |
| return -EINVAL; |
| |
| if (len < skb->len) { |
| /* Packet will be striped */ |
| pi.flags |= TUN_PKT_STRIP; |
| } |
| |
| memcpy_toiovec(iv, (void *) &pi, sizeof(pi)); |
| total += sizeof(pi); |
| } |
| |
| len = MIN(skb->len, len); |
| |
| skb_copy_datagram_iovec(skb, 0, iv, len); |
| total += len; |
| |
| tun->stats.tx_packets++; |
| tun->stats.tx_bytes += len; |
| |
| return total; |
| } |
| |
| /* Readv */ |
| static ssize_t tun_chr_readv(struct file *file, const struct iovec *iv, |
| unsigned long count, loff_t *pos) |
| { |
| struct tun_struct *tun = (struct tun_struct *)file->private_data; |
| DECLARE_WAITQUEUE(wait, current); |
| struct sk_buff *skb; |
| ssize_t len, ret = 0; |
| unsigned long i; |
| |
| if (!tun) |
| return -EBADFD; |
| |
| DBG(KERN_INFO "%s: tun_chr_read\n", tun->name); |
| |
| for (i = 0, len = 0; i < count; i++) { |
| if (verify_area(VERIFY_WRITE, iv[i].iov_base, iv[i].iov_len)) |
| return -EFAULT; |
| len += iv[i].iov_len; |
| } |
| |
| add_wait_queue(&tun->read_wait, &wait); |
| while (len) { |
| current->state = TASK_INTERRUPTIBLE; |
| |
| /* Read frames from the queue */ |
| if (!(skb=skb_dequeue(&tun->readq))) { |
| if (file->f_flags & O_NONBLOCK) { |
| ret = -EAGAIN; |
| break; |
| } |
| if (signal_pending(current)) { |
| ret = -ERESTARTSYS; |
| break; |
| } |
| |
| /* Nothing to read, let's sleep */ |
| schedule(); |
| continue; |
| } |
| netif_start_queue(&tun->dev); |
| |
| ret = tun_put_user(tun, skb, (struct iovec *) iv, len); |
| |
| kfree_skb(skb); |
| break; |
| } |
| |
| current->state = TASK_RUNNING; |
| remove_wait_queue(&tun->read_wait, &wait); |
| |
| return ret; |
| } |
| |
| /* Read */ |
| static ssize_t tun_chr_read(struct file * file, char * buf, |
| size_t count, loff_t *pos) |
| { |
| struct iovec iv = { buf, count }; |
| return tun_chr_readv(file, &iv, 1, pos); |
| } |
| |
| static int tun_set_iff(struct file *file, struct ifreq *ifr) |
| { |
| struct tun_struct *tun; |
| struct net_device *dev; |
| int err; |
| |
| dev = __dev_get_by_name(ifr->ifr_name); |
| if (dev) { |
| /* Device exist */ |
| tun = dev->priv; |
| |
| if (dev->init != tun_net_init || tun->attached) |
| return -EBUSY; |
| |
| /* Check permissions */ |
| if (tun->owner != -1) |
| if (current->euid != tun->owner && !capable(CAP_NET_ADMIN)) |
| return -EPERM; |
| } else { |
| char *name; |
| |
| /* Allocate new device */ |
| if (!(tun = kmalloc(sizeof(struct tun_struct), GFP_KERNEL)) ) |
| return -ENOMEM; |
| memset(tun, 0, sizeof(struct tun_struct)); |
| |
| skb_queue_head_init(&tun->readq); |
| init_waitqueue_head(&tun->read_wait); |
| |
| tun->owner = -1; |
| tun->dev.init = tun_net_init; |
| tun->dev.priv = tun; |
| |
| err = -EINVAL; |
| |
| /* Set dev type */ |
| if (ifr->ifr_flags & IFF_TUN) { |
| /* TUN device */ |
| tun->flags |= TUN_TUN_DEV; |
| name = "tun%d"; |
| } else if (ifr->ifr_flags & IFF_TAP) { |
| /* TAP device */ |
| tun->flags |= TUN_TAP_DEV; |
| name = "tap%d"; |
| } else |
| goto failed; |
| |
| if (*ifr->ifr_name) |
| name = ifr->ifr_name; |
| |
| if ((err = dev_alloc_name(&tun->dev, name)) < 0) |
| goto failed; |
| if ((err = register_netdevice(&tun->dev))) |
| goto failed; |
| |
| MOD_INC_USE_COUNT; |
| |
| tun->name = tun->dev.name; |
| } |
| |
| DBG(KERN_INFO "%s: tun_set_iff\n", tun->name); |
| |
| if (ifr->ifr_flags & IFF_NO_PI) |
| tun->flags |= TUN_NO_PI; |
| |
| if (ifr->ifr_flags & IFF_ONE_QUEUE) |
| tun->flags |= TUN_ONE_QUEUE; |
| |
| file->private_data = tun; |
| tun->attached = 1; |
| |
| strcpy(ifr->ifr_name, tun->name); |
| return 0; |
| |
| failed: |
| kfree(tun); |
| return err; |
| } |
| |
| static int tun_chr_ioctl(struct inode *inode, struct file *file, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct tun_struct *tun = (struct tun_struct *)file->private_data; |
| |
| if (cmd == TUNSETIFF && !tun) { |
| struct ifreq ifr; |
| int err; |
| |
| if (copy_from_user(&ifr, (void *)arg, sizeof(ifr))) |
| return -EFAULT; |
| ifr.ifr_name[IFNAMSIZ-1] = '\0'; |
| |
| rtnl_lock(); |
| err = tun_set_iff(file, &ifr); |
| rtnl_unlock(); |
| |
| if (err) |
| return err; |
| |
| copy_to_user((void *)arg, &ifr, sizeof(ifr)); |
| return 0; |
| } |
| |
| if (!tun) |
| return -EBADFD; |
| |
| DBG(KERN_INFO "%s: tun_chr_ioctl cmd %d\n", tun->name, cmd); |
| |
| switch (cmd) { |
| case TUNSETNOCSUM: |
| /* Disable/Enable checksum */ |
| if (arg) |
| tun->flags |= TUN_NOCHECKSUM; |
| else |
| tun->flags &= ~TUN_NOCHECKSUM; |
| |
| DBG(KERN_INFO "%s: checksum %s\n", |
| tun->name, arg ? "disabled" : "enabled"); |
| break; |
| |
| case TUNSETPERSIST: |
| /* Disable/Enable persist mode */ |
| if (arg) |
| tun->flags |= TUN_PERSIST; |
| else |
| tun->flags &= ~TUN_PERSIST; |
| |
| DBG(KERN_INFO "%s: persist %s\n", |
| tun->name, arg ? "disabled" : "enabled"); |
| break; |
| |
| case TUNSETOWNER: |
| /* Set owner of the device */ |
| tun->owner = (uid_t) arg; |
| |
| DBG(KERN_INFO "%s: owner set to %d\n", tun->owner); |
| break; |
| |
| #ifdef TUN_DEBUG |
| case TUNSETDEBUG: |
| tun->debug = arg; |
| break; |
| #endif |
| |
| default: |
| return -EINVAL; |
| }; |
| |
| return 0; |
| } |
| |
| static int tun_chr_fasync(int fd, struct file *file, int on) |
| { |
| struct tun_struct *tun = (struct tun_struct *)file->private_data; |
| int ret; |
| |
| if (!tun) |
| return -EBADFD; |
| |
| DBG(KERN_INFO "%s: tun_chr_fasync %d\n", tun->name, on); |
| |
| if ((ret = fasync_helper(fd, file, on, &tun->fasync)) < 0) |
| return ret; |
| |
| if (on) { |
| tun->flags |= TUN_FASYNC; |
| if (!file->f_owner.pid) { |
| file->f_owner.pid = current->pid; |
| file->f_owner.uid = current->uid; |
| file->f_owner.euid = current->euid; |
| } |
| } else |
| tun->flags &= ~TUN_FASYNC; |
| |
| return 0; |
| } |
| |
| static int tun_chr_open(struct inode *inode, struct file * file) |
| { |
| DBG1(KERN_INFO "tunX: tun_chr_open\n"); |
| file->private_data = NULL; |
| return 0; |
| } |
| |
| static int tun_chr_close(struct inode *inode, struct file *file) |
| { |
| struct tun_struct *tun = (struct tun_struct *)file->private_data; |
| |
| if (!tun) |
| return 0; |
| |
| DBG(KERN_INFO "%s: tun_chr_close\n", tun->name); |
| |
| tun_chr_fasync(-1, file, 0); |
| |
| rtnl_lock(); |
| |
| /* Detach from net device */ |
| file->private_data = NULL; |
| tun->attached = 0; |
| |
| /* Drop read queue */ |
| skb_queue_purge(&tun->readq); |
| |
| if (!(tun->flags & TUN_PERSIST)) { |
| dev_close(&tun->dev); |
| unregister_netdevice(&tun->dev); |
| kfree(tun); |
| MOD_DEC_USE_COUNT; |
| } |
| |
| rtnl_unlock(); |
| return 0; |
| } |
| |
| static struct file_operations tun_fops = { |
| owner: THIS_MODULE, |
| llseek: no_llseek, |
| read: tun_chr_read, |
| readv: tun_chr_readv, |
| write: tun_chr_write, |
| writev: tun_chr_writev, |
| poll: tun_chr_poll, |
| ioctl: tun_chr_ioctl, |
| open: tun_chr_open, |
| release:tun_chr_close, |
| fasync: tun_chr_fasync |
| }; |
| |
| static struct miscdevice tun_miscdev= |
| { |
| TUN_MINOR, |
| "net/tun", |
| &tun_fops |
| }; |
| |
| int __init tun_init(void) |
| { |
| printk(KERN_INFO "Universal TUN/TAP device driver %s " |
| "(C)1999-2002 Maxim Krasnyansky\n", TUN_VER); |
| |
| if (misc_register(&tun_miscdev)) { |
| printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR); |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| |
| void tun_cleanup(void) |
| { |
| misc_deregister(&tun_miscdev); |
| } |
| |
| module_init(tun_init); |
| module_exit(tun_cleanup); |
| MODULE_LICENSE("GPL"); |