package/lqtapi/src/tapi/tapi-stream.c

   1 #include <linux/cdev.h>
   2 #include <linux/device.h>
   3 #include <linux/fs.h>
   4 #include <linux/list.h>
   5 #include <linux/kernel.h>
   6 #include <linux/module.h>
   7 #include <linux/slab.h>
   8 #include <linux/signal.h>
   9 #include <linux/sched.h>
  10 #include <linux/poll.h>
  11
  12 #include <linux/tapi/tapi.h>
  13 #include <linux/tapi/tapi-ioctl.h>
  14
  15
  16 struct tapi_stream_file {
  17         struct tapi_device *tdev;
  18         struct tapi_stream *stream;
  19 };
  20
  21 static inline struct tapi_device *inode_to_tdev(struct inode *inode)
  22 {
  23         return container_of(inode->i_cdev, struct tapi_char_device, cdev)->tdev;
  24 }
  25
  26 static int tapi_stream_open(struct inode *inode, struct file *file)
  27 {
  28         int ret;
  29         struct tapi_device *tdev = inode_to_tdev(inode);
  30         struct tapi_stream_file *stream;
  31
  32         get_device(&tdev->dev);
  33
  34         stream = kzalloc(sizeof(*stream), GFP_KERNEL);
  35         if (!stream) {
  36                 ret = -ENOMEM;
  37                 goto err_put;
  38         }
  39
  40         stream->stream = tapi_stream_alloc(tdev);
  41         if (IS_ERR(stream->stream)) {
  42                 ret = PTR_ERR(stream->stream);
  43                 goto err_free;
  44         }
  45         stream->tdev = tdev;
  46
  47         init_waitqueue_head(&stream->stream->recv_wait);
  48         skb_queue_head_init(&stream->stream->recv_queue);
  49
  50         file->private_data = stream;
  51
  52         return 0;
  53
  54 err_free:
  55         kfree(stream);
  56 err_put:
  57         put_device(&tdev->dev);
  58         return ret;
  59 }
  60
  61 static int tapi_stream_release(struct inode *inode, struct file *file)
  62 {
  63         struct tapi_stream_file *stream = file->private_data;
  64
  65         if (stream) {
  66                 tapi_stream_free(stream->tdev, stream->stream);
  67                 put_device(&stream->tdev->dev);
  68                 kfree(stream);
  69         }
  70
  71         return 0;
  72 }
  73
  74 static long tapi_stream_ioctl(struct file *file, unsigned int cmd,
  75         unsigned long arg)
  76 {
  77         int ret = 0;
  78         struct tapi_stream_file *stream = file->private_data;
  79         struct tapi_device *tdev = stream->tdev;
  80
  81         switch (cmd) {
  82         case TAPI_STREAM_IOCTL_GET_ENDPOINT:
  83                 ret = stream->stream->ep.id;
  84                 break;
  85         case TAPI_STREAM_IOCTL_CONFIGURE:
  86                 break;
  87         case TAPI_STREAM_IOCTL_START:
  88                 ret = tapi_stream_start(tdev, stream->stream);
  89                 break;
  90         case TAPI_STREAM_IOCTL_STOP:
  91                 ret = tapi_stream_stop(tdev, stream->stream);
  92                 break;
  93         default:
  94                 ret = -EINVAL;
  95                 break;
  96         }
  97
  98         return ret;
  99 }
 100
 101 static unsigned int tapi_stream_poll(struct file *file, struct poll_table_struct *wait)
 102 {
 103         struct tapi_stream_file *stream = file->private_data;
 104         int ret;
 105
 106         poll_wait(file, &stream->stream->recv_wait, wait);
 107
 108         ret = POLLOUT;
 109
 110         if (!skb_queue_empty(&stream->stream->recv_queue))
 111                 ret |= POLLIN;
 112
 113         return ret;
 114 }
 115
 116 static ssize_t tapi_stream_read(struct file *file, char __user *buffer,
 117         size_t count, loff_t *offset)
 118 {
 119         struct tapi_stream_file *stream = file->private_data;
 120         struct sk_buff *skb;
 121
 122         skb = skb_dequeue(&stream->stream->recv_queue);
 123         if (!skb) {
 124                 if (file->f_flags & O_NONBLOCK)
 125                         return -EAGAIN;
 126
 127                 do {
 128                         interruptible_sleep_on(&stream->stream->recv_wait);
 129                         skb = skb_dequeue(&stream->stream->recv_queue);
 130                 } while (skb == NULL && !signal_pending(current));
 131
 132                 if (skb == NULL)
 133                         return -ERESTARTNOHAND;
 134         }
 135
 136         if (skb->len > count) {
 137                 skb_queue_head(&stream->stream->recv_queue, skb);
 138                 return -EMSGSIZE;
 139         }
 140
 141         if (copy_to_user(buffer, skb->data, skb->len)) {
 142                 skb_queue_head(&stream->stream->recv_queue, skb);
 143                 return -EFAULT;
 144         }
 145
 146         count = skb->len;
 147
 148         kfree_skb(skb);
 149
 150         return count;
 151 }
 152
 153 static ssize_t tapi_stream_write(struct file *file, const char __user *buffer,
 154         size_t count, loff_t *ppos)
 155 {
 156         struct tapi_stream_file *stream = file->private_data;
 157         struct tapi_device *tdev = stream->tdev;
 158         struct sk_buff *skb;
 159
 160         if (count == 0)
 161                 return 0;
 162
 163         skb = alloc_skb(count, GFP_USER);
 164         if (!skb)
 165                 return -ENOMEM;
 166
 167         if (copy_from_user(skb_put(skb, count), buffer, count)) {
 168                 kfree_skb(skb);
 169                 return -EFAULT;
 170         }
 171
 172         tdev->ops->stream_send(tdev, stream->stream, skb);
 173
 174         return count;
 175 }
 176
 177 static const struct file_operations tapi_stream_file_ops = {
 178         .owner = THIS_MODULE,
 179         .read = tapi_stream_read,
 180         .write = tapi_stream_write,
 181         .open = tapi_stream_open,
 182         .release = tapi_stream_release,
 183         .poll = tapi_stream_poll,
 184         .unlocked_ioctl = tapi_stream_ioctl,
 185 };
 186
 187 int tapi_register_stream_device(struct tapi_device* tdev)
 188 {
 189         dev_set_name(&tdev->stream_dev.dev, "tapi%uS", tdev->id);
 190         return tapi_char_device_register(tdev, &tdev->stream_dev, &tapi_stream_file_ops);
 191 }
 192
 193 int tapi_stream_recv(struct tapi_device *tdev, struct tapi_stream * stream,
 194         struct sk_buff *skb)
 195 {
 196         skb_queue_tail(&stream->recv_queue, skb);
 197         wake_up(&stream->recv_wait);
 198
 199         return 0;
 200 }
 201 EXPORT_SYMBOL_GPL(tapi_stream_recv);