patch-2.4.0-test7 linux/drivers/net/tun.c

• Lines: 536
• Date: Wed Aug 23 09:30:13 2000
• Orig file: v2.4.0-test6/linux/drivers/net/tun.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test6/linux/drivers/net/tun.c linux/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);