/* 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 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;
}
