summaryrefslogtreecommitdiffstats
path: root/drivers/net/tun.c
diff options
context:
space:
mode:
authorRalf Baechle <ralf@linux-mips.org>2000-08-28 22:00:09 +0000
committerRalf Baechle <ralf@linux-mips.org>2000-08-28 22:00:09 +0000
commit1a1d77dd589de5a567fa95e36aa6999c704ceca4 (patch)
tree141e31f89f18b9fe0831f31852e0435ceaccafc5 /drivers/net/tun.c
parentfb9c690a18b3d66925a65b17441c37fa14d4370b (diff)
Merge with 2.4.0-test7.
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c535
1 files changed, 535 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
new file mode 100644
index 000000000..26282e38f
--- /dev/null
+++ b/drivers/net/tun.c
@@ -0,0 +1,535 @@
+/*
+ * TUN - Universal TUN/TAP device driver.
+ * Copyright (C) 1999-2000 Maxim Krasnyansky <max_mk@yahoo.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 1.1 2000/08/23 05:59:28 davem Exp $
+ */
+
+/*
+ * Daniel Podlejski <underley@underley.eu.org>
+ * Modifications for 2.3.99-pre5 kernel.
+ */
+
+#define TUN_VER "1.1"
+
+#include <linux/module.h>
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/sched.h>
+#include <linux/malloc.h>
+#include <linux/poll.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/random.h>
+
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.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=0;
+#endif
+
+/* Network device part of the driver */
+
+/* Net device open. */
+static int tun_net_open(struct net_device *dev)
+{
+#ifdef TUN_DEBUG
+ struct tun_struct *tun = (struct tun_struct *)dev->priv;
+
+ DBG(KERN_INFO "%s: tun_net_open\n", tun->name);
+#endif
+
+ netif_start_queue(dev);
+
+ return 0;
+}
+
+/* Net device close. */
+static int tun_net_close(struct net_device *dev)
+{
+#ifdef TUN_DEBUG
+ struct tun_struct *tun = (struct tun_struct *)dev->priv;
+
+ DBG(KERN_INFO "%s: tun_net_close\n", tun->name);
+#endif
+
+ 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);
+
+
+ if (netif_queue_stopped(dev))
+ return 1;
+
+ tun->stats.tx_packets++;
+
+ /* Queue frame */
+ skb_queue_tail(&tun->txq, skb);
+ if (skb_queue_len(&tun->txq) >= TUN_TXQ_SIZE)
+ netif_stop_queue(dev);
+
+ if (tun->flags & TUN_FASYNC)
+ kill_fasync(&tun->fasync, SIGIO, POLL_IN);
+
+ /* Wake up process */
+ wake_up_interruptible(&tun->read_wait);
+
+ return 0;
+}
+
+static void tun_net_mclist(struct net_device *dev)
+{
+#ifdef TUN_DEBUG
+ struct tun_struct *tun = (struct tun_struct *)dev->priv;
+
+ DBG(KERN_INFO "%s: tun_net_mclist\n", tun->name);
+#endif
+
+ /* 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;
+}
+
+/* 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);
+
+ 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;
+
+ /* Type PPP seems most suitable */
+ dev->type = ARPHRD_PPP;
+ dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+ dev->tx_queue_len = 10;
+
+ dev_init_buffers(dev);
+ 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;
+ };
+
+ 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;
+
+ DBG(KERN_INFO "%s: tun_chr_poll\n", tun->name);
+
+ poll_wait(file, &tun->read_wait, wait);
+
+ if (skb_queue_len(&tun->txq))
+ return POLLIN | POLLRDNORM;
+
+ return POLLOUT | POLLWRNORM;
+}
+
+/* Get packet from user space buffer(already verified) */
+static __inline__ ssize_t tun_get_user(struct tun_struct *tun, const char *buf, size_t count)
+{
+ struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
+ register const char *ptr = buf;
+ register int len = count;
+ struct sk_buff *skb;
+
+ if (len > TUN_MAX_FRAME)
+ return -EINVAL;
+
+ if (!(tun->flags & TUN_NO_PI)) {
+ if ((len -= sizeof(pi)) < 0)
+ return -EINVAL;
+
+ copy_from_user(&pi, ptr, sizeof(pi));
+ ptr += sizeof(pi);
+ }
+
+ if (!(skb = alloc_skb(len + 2, GFP_KERNEL))) {
+ tun->stats.rx_dropped++;
+ return -ENOMEM;
+ }
+
+ skb_reserve(skb, 2);
+ copy_from_user(skb_put(skb, count), ptr, 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(skb);
+
+ tun->stats.rx_packets++;
+ return count;
+}
+
+/* Write */
+static ssize_t tun_chr_write(struct file * file, const char * buf,
+ size_t count, loff_t *pos)
+{
+ struct tun_struct *tun = (struct tun_struct *)file->private_data;
+
+ DBG(KERN_INFO "%s: tun_chr_write %d\n", tun->name, count);
+
+ if (!(tun->flags & TUN_IFF_SET))
+ return -EBUSY;
+
+ if (verify_area(VERIFY_READ, buf, count))
+ return -EFAULT;
+
+ return tun_get_user(tun, buf, count);
+}
+
+/* Put packet to user space buffer(already verified) */
+static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
+ struct sk_buff *skb,
+ char *buf, int count)
+{
+ struct tun_pi pi = { 0, skb->protocol };
+ int len = count, total = 0;
+ char *ptr = buf;
+
+ 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;
+ }
+
+ copy_to_user(ptr, &pi, sizeof(pi));
+
+ total += sizeof(pi);
+ ptr += sizeof(pi);
+ }
+
+ len = MIN(skb->len, len);
+ copy_to_user(ptr, skb->data, len);
+ total += len;
+
+ return total;
+}
+
+/* Read */
+static ssize_t tun_chr_read(struct file * file, char * buf,
+ size_t count, loff_t *pos)
+{
+ struct tun_struct *tun = (struct tun_struct *)file->private_data;
+ DECLARE_WAITQUEUE(wait, current);
+ struct sk_buff *skb;
+ ssize_t ret = 0;
+
+ DBG(KERN_INFO "%s: tun_chr_read\n", tun->name);
+
+ add_wait_queue(&tun->read_wait, &wait);
+ while (count) {
+ current->state = TASK_INTERRUPTIBLE;
+
+ /* Read frames from device queue */
+ if (!(skb=skb_dequeue(&tun->txq))) {
+ 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);
+
+ if (!verify_area(VERIFY_WRITE, buf, count))
+ ret = tun_put_user(tun, skb, buf, count);
+ else
+ ret = -EFAULT;
+
+ kfree_skb(skb);
+ break;
+ }
+
+ current->state = TASK_RUNNING;
+ remove_wait_queue(&tun->read_wait, &wait);
+
+ return ret;
+}
+
+static loff_t tun_chr_lseek(struct file * file, loff_t offset, int origin)
+{
+ return -ESPIPE;
+}
+
+static int tun_set_iff(struct tun_struct *tun, unsigned long arg)
+{
+ struct ifreq ifr;
+ char *mask;
+
+ if (copy_from_user(&ifr, (void *)arg, sizeof(ifr)))
+ return -EFAULT;
+ ifr.ifr_name[IFNAMSIZ-1] = '\0';
+
+ if (tun->flags & TUN_IFF_SET)
+ return -EEXIST;
+
+ /* Set dev type */
+ if (ifr.ifr_flags & IFF_TUN) {
+ /* TUN device */
+ tun->flags |= TUN_TUN_DEV;
+ mask = "tun%d";
+ } else if (ifr.ifr_flags & IFF_TAP) {
+ /* TAP device */
+ tun->flags |= TUN_TAP_DEV;
+ mask = "tap%d";
+ } else
+ return -EINVAL;
+
+ if (ifr.ifr_flags & IFF_NO_PI)
+ tun->flags |= TUN_NO_PI;
+
+ if (*ifr.ifr_name)
+ strcpy(tun->dev.name, ifr.ifr_name);
+ else
+ strcpy(tun->dev.name, mask);
+
+ /* Register net device */
+ if (register_netdev(&tun->dev))
+ return -EBUSY;
+
+ tun->flags |= TUN_IFF_SET;
+ strcpy(tun->name, tun->dev.name);
+
+ /* Return iface info to the user space */
+ strcpy(ifr.ifr_name, tun->dev.name);
+ copy_to_user((void *)arg, &ifr, sizeof(ifr));
+
+ return 0;
+}
+
+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;
+
+ DBG(KERN_INFO "%s: tun_chr_ioctl\n", tun->name);
+
+ switch (cmd) {
+ case TUNSETIFF:
+ return tun_set_iff(tun, arg);
+
+ case TUNSETNOCSUM:
+ /* Disable/Enable checksum on net iface */
+ if (arg)
+ tun->flags |= TUN_NOCHECKSUM;
+ else
+ tun->flags &= ~TUN_NOCHECKSUM;
+
+ DBG(KERN_INFO "%s: checksum %s\n",
+ tun->name, arg ? "disabled" : "enabled");
+ 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;
+
+ 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;
+ else
+ tun->flags &= ~TUN_FASYNC;
+
+ return 0;
+}
+
+static int tun_chr_open(struct inode *inode, struct file * file)
+{
+ struct tun_struct *tun = NULL;
+
+ DBG1(KERN_INFO "tunX: tun_chr_open\n");
+
+ tun = kmalloc(sizeof(struct tun_struct), GFP_KERNEL);
+ if (tun == NULL)
+ return -ENOMEM;
+
+ memset(tun, 0, sizeof(struct tun_struct));
+ file->private_data = tun;
+
+ skb_queue_head_init(&tun->txq);
+ init_waitqueue_head(&tun->read_wait);
+
+ sprintf(tun->name, "tunX");
+
+ tun->dev.init = tun_net_init;
+ tun->dev.priv = tun;
+
+ MOD_INC_USE_COUNT;
+
+ return 0;
+}
+
+static int tun_chr_close(struct inode *inode, struct file *file)
+{
+ struct tun_struct *tun = (struct tun_struct *)file->private_data;
+
+ DBG(KERN_INFO "%s: tun_chr_close\n", tun->name);
+
+ if (tun->flags & TUN_IFF_SET) {
+ rtnl_lock();
+ dev_close(&tun->dev);
+ rtnl_unlock();
+
+ /* Drop TX queue */
+ skb_queue_purge(&tun->txq);
+
+ unregister_netdev(&tun->dev);
+ }
+
+ kfree(tun);
+ file->private_data = NULL;
+
+ MOD_DEC_USE_COUNT;
+ return 0;
+}
+
+static struct file_operations tun_fops = {
+ owner: THIS_MODULE,
+ llseek: tun_chr_lseek,
+ read: tun_chr_read,
+ write: tun_chr_write,
+ poll: tun_chr_poll,
+ ioctl: tun_chr_ioctl,
+ open: tun_chr_open,
+ release:tun_chr_close,
+ fasync: tun_chr_fasync
+};
+
+static devfs_handle_t devfs_handle = NULL;
+
+int __init tun_init(void)
+{
+ printk(KERN_INFO "Universal TUN/TAP device driver %s "
+ "(C)1999-2000 Maxim Krasnyansky\n", TUN_VER);
+
+ if (devfs_register_chrdev(TUN_MAJOR, "tun", &tun_fops)) {
+ printk(KERN_ERR "tun: Can't register char device %d\n",
+ TUN_MAJOR);
+ return -EIO;
+ }
+
+ devfs_handle = devfs_register(NULL, "net/tun", DEVFS_FL_DEFAULT,
+ TUN_MAJOR, 0,
+ S_IFCHR | S_IRUSR | S_IWUSR,
+ &tun_fops, NULL);
+
+#ifdef MODULE
+ return 0;
+#else
+ /* If driver is not module, tun_init will be called from Space.c.
+ * Return non-zero not to register fake device.
+ */
+ return 1;
+#endif
+}
+
+void tun_cleanup(void)
+{
+ devfs_unregister_chrdev(TUN_MAJOR,"tun");
+ devfs_unregister(devfs_handle);
+}
+
+module_init(tun_init);
+module_exit(tun_cleanup);