/*
 * $Id: capi.c,v 1.10 1998/02/13 07:09:13 calle Exp $
 *
 * CAPI 2.0 Interface for Linux
 *
 * Copyright 1996 by Carsten Paeth (calle@calle.in-berlin.de)
 *
 * $Log: capi.c,v $
 * Revision 1.10  1998/02/13 07:09:13  calle
 * change for 2.1.86 (removing FREE_READ/FREE_WRITE from [dev]_kfree_skb()
 *
 * Revision 1.9  1998/01/31 11:14:44  calle
 * merged changes to 2.0 tree, prepare 2.1.82 to work.
 *
 * Revision 1.8  1997/11/04 06:12:08  calle
 * capi.c: new read/write in file_ops since 2.1.60
 * capidrv.c: prepared isdnlog interface for d2-trace in newer firmware.
 * capiutil.c: needs config.h (CONFIG_ISDN_DRV_AVMB1_VERBOSE_REASON)
 * compat.h: added #define LinuxVersionCode
 *
 * Revision 1.7  1997/10/11 10:29:34  calle
 * llseek() parameters changed in 2.1.56.
 *
 * Revision 1.6  1997/10/01 09:21:15  fritz
 * Removed old compatibility stuff for 2.0.X kernels.
 * From now on, this code is for 2.1.X ONLY!
 * Old stuff is still in the separate branch.
 *
 * Revision 1.5  1997/08/21 23:11:55  fritz
 * Added changes for kernels >= 2.1.45
 *
 * Revision 1.4  1997/05/27 15:17:50  fritz
 * Added changes for recent 2.1.x kernels:
 *   changed return type of isdn_close
 *   queue_task_* -> queue_task
 *   clear/set_bit -> test_and_... where apropriate.
 *   changed type of hard_header_cache parameter.
 *
 * Revision 1.3  1997/05/18 09:24:14  calle
 * added verbose disconnect reason reporting to avmb1.
 * some fixes in capi20 interface.
 * changed info messages for B1-PCI
 *
 * Revision 1.2  1997/03/05 21:17:59  fritz
 * Added capi_poll for compiling under 2.1.27
 *
 * Revision 1.1  1997/03/04 21:50:29  calle
 * Frirst version in isdn4linux
 *
 * Revision 2.2  1997/02/12 09:31:39  calle
 * new version
 *
 * Revision 1.1  1997/01/31 10:32:20  calle
 * Initial revision
 *
 */

#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/fcntl.h>
#include <linux/fs.h>
#include <linux/signal.h>
#include <linux/mm.h>
#include <linux/timer.h>
#include <linux/wait.h>
#include <linux/skbuff.h>
#include <linux/poll.h>
#include <linux/capi.h>
#include <linux/kernelcapi.h>

#include "compat.h"
#include "capiutil.h"
#include "capicmd.h"
#include "capidev.h"

MODULE_AUTHOR("Carsten Paeth (calle@calle.in-berlin.de)");

/* -------- driver information -------------------------------------- */

int capi_major = 68;		/* allocated */

MODULE_PARM(capi_major, "i");

/* -------- global variables ---------------------------------------- */

static struct capidev capidevs[CAPI_MAXMINOR + 1];
struct capi_interface *capifuncs;

/* -------- function called by lower level -------------------------- */

static void capi_signal(__u16 applid, __u32 minor)
{
	struct capidev *cdev;
	struct sk_buff *skb = 0;

	if (minor > CAPI_MAXMINOR || !capidevs[minor].is_registered) {
		printk(KERN_ERR "BUG: capi_signal: illegal minor %d\n", minor);
		return;
	}
	cdev = &capidevs[minor];
	(void) (*capifuncs->capi_get_message) (applid, &skb);
	if (skb) {
		skb_queue_tail(&cdev->recv_queue, skb);
		wake_up_interruptible(&cdev->recv_wait);
	} else {
		printk(KERN_ERR "BUG: capi_signal: no skb\n");
	}
}

/* -------- file_operations ----------------------------------------- */

static long long capi_llseek(struct file *file,
			     long long offset, int origin)
{
	return -ESPIPE;
}

static ssize_t capi_read(struct file *file, char *buf,
		      size_t count, loff_t *ppos)
{
        struct inode *inode = file->f_dentry->d_inode;
	unsigned int minor = MINOR(inode->i_rdev);
	struct capidev *cdev;
	struct sk_buff *skb;
	int retval;
	size_t copied;

       if (ppos != &file->f_pos)
		return -ESPIPE;

	if (!minor || minor > CAPI_MAXMINOR || !capidevs[minor].is_registered)
		return -ENODEV;

	cdev = &capidevs[minor];

	if ((skb = skb_dequeue(&cdev->recv_queue)) == 0) {

		if (file->f_flags & O_NONBLOCK)
			return -EAGAIN;

		for (;;) {
			interruptible_sleep_on(&cdev->recv_wait);
			if ((skb = skb_dequeue(&cdev->recv_queue)) != 0)
				break;
			if (signal_pending(current))
				break;
		}
		if (skb == 0)
			return -ERESTARTNOHAND;
	}
	if (skb->len > count) {
		skb_queue_head(&cdev->recv_queue, skb);
		return -EMSGSIZE;
	}
	if (CAPIMSG_COMMAND(skb->data) == CAPI_DATA_B3
	    && CAPIMSG_SUBCOMMAND(skb->data) == CAPI_IND)
		CAPIMSG_SETDATA(skb->data, buf + CAPIMSG_LEN(skb->data));
	retval = copy_to_user(buf, skb->data, skb->len);
	if (retval) {
		skb_queue_head(&cdev->recv_queue, skb);
		return retval;
	}
	copied = skb->len;


	kfree_skb(skb);

	return copied;
}

static ssize_t capi_write(struct file *file, const char *buf,
		       size_t count, loff_t *ppos)
{
        struct inode *inode = file->f_dentry->d_inode;
	unsigned int minor = MINOR(inode->i_rdev);
	struct capidev *cdev;
	struct sk_buff *skb;
	int retval;
	__u8 cmd;
	__u8 subcmd;
	__u16 mlen;

       if (ppos != &file->f_pos)
		return -ESPIPE;

	if (!minor || minor > CAPI_MAXMINOR || !capidevs[minor].is_registered)
		return -ENODEV;

	cdev = &capidevs[minor];

	skb = alloc_skb(count, GFP_USER);

	if ((retval = copy_from_user(skb_put(skb, count), buf, count))) {
		dev_kfree_skb(skb);
		return retval;
	}
	cmd = CAPIMSG_COMMAND(skb->data);
	subcmd = CAPIMSG_SUBCOMMAND(skb->data);
	mlen = CAPIMSG_LEN(skb->data);
	if (cmd == CAPI_DATA_B3 && subcmd == CAPI_REQ) {
		__u16 dlen = CAPIMSG_DATALEN(skb->data);
		if (mlen + dlen != count) {
			dev_kfree_skb(skb);
			return -EINVAL;
		}
	} else if (mlen != count) {
		dev_kfree_skb(skb);
		return -EINVAL;
	}
	CAPIMSG_SETAPPID(skb->data, cdev->applid);

	cdev->errcode = (*capifuncs->capi_put_message) (cdev->applid, skb);

	if (cdev->errcode) {
		dev_kfree_skb(skb);
		return -EIO;
	}
	return count;
}

static unsigned int
capi_poll(struct file *file, poll_table * wait)
{
	unsigned int mask = 0;
#if (LINUX_VERSION_CODE >= 0x02012d)
	unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
#else
	unsigned int minor = MINOR(file->f_inode->i_rdev);
#endif
	struct capidev *cdev;

	if (!minor || minor > CAPI_MAXMINOR || !capidevs[minor].is_registered)
		return POLLERR;

	cdev = &capidevs[minor];
	poll_wait(file, &(cdev->recv_wait), wait);
	mask = POLLOUT | POLLWRNORM;
	if (!skb_queue_empty(&cdev->recv_queue))
		mask |= POLLIN | POLLRDNORM;
	return mask;
}

static int capi_ioctl(struct inode *inode, struct file *file,
		      unsigned int cmd, unsigned long arg)
{
	unsigned int minor = MINOR(inode->i_rdev);
	struct capidev *cdev;
	capi_ioctl_struct data;
	int retval;


	if (minor >= CAPI_MAXMINOR || !capidevs[minor].is_open)
		return -ENODEV;

	cdev = &capidevs[minor];

	switch (cmd) {
	case CAPI_REGISTER:
		{
			if (!minor)
				return -EINVAL;
			retval = copy_from_user((void *) &data.rparams,
						(void *) arg, sizeof(struct capi_register_params));
			if (retval)
				return -EFAULT;
			if (cdev->is_registered)
				return -EEXIST;
			cdev->errcode = (*capifuncs->capi_register) (&data.rparams,
							  &cdev->applid);
			if (cdev->errcode)
				return -EIO;
			(void) (*capifuncs->capi_set_signal) (cdev->applid, capi_signal, minor);
			cdev->is_registered = 1;
		}
		return 0;

	case CAPI_GET_VERSION:
		{
			retval = copy_from_user((void *) &data.contr,
						(void *) arg,
						sizeof(data.contr));
			if (retval)
				return -EFAULT;
		        cdev->errcode = (*capifuncs->capi_get_version) (data.contr, &data.version);
			if (cdev->errcode)
				return -EIO;
			retval = copy_to_user((void *) arg,
					      (void *) &data.version,
					      sizeof(data.version));
			if (retval)
				return -EFAULT;
		}
		return 0;

	case CAPI_GET_SERIAL:
		{
			retval = copy_from_user((void *) &data.contr,
						(void *) arg,
						sizeof(data.contr));
			if (retval)
				return -EFAULT;
			cdev->errcode = (*capifuncs->capi_get_serial) (data.contr, data.serial);
			if (cdev->errcode)
				return -EIO;
			retval = copy_to_user((void *) arg,
					      (void *) data.serial,
					      sizeof(data.serial));
			if (retval)
				return -EFAULT;
		}
		return 0;
	case CAPI_GET_PROFILE:
		{
			retval = copy_from_user((void *) &data.contr,
						(void *) arg,
						sizeof(data.contr));
			if (retval)
				return -EFAULT;

			if (data.contr == 0) {
				cdev->errcode = (*capifuncs->capi_get_profile) (data.contr, &data.profile);
				if (cdev->errcode)
					return -EIO;

				retval = copy_to_user((void *) arg,
				      (void *) &data.profile.ncontroller,
				       sizeof(data.profile.ncontroller));

			} else {
				cdev->errcode = (*capifuncs->capi_get_profile) (data.contr, &data.profile);
				if (cdev->errcode)
					return -EIO;

				retval = copy_to_user((void *) arg,
						  (void *) &data.profile,
						   sizeof(data.profile));
			}
			if (retval)
				return -EFAULT;
		}
		return 0;

	case CAPI_GET_MANUFACTURER:
		{
			retval = copy_from_user((void *) &data.contr,
						(void *) arg,
						sizeof(data.contr));
			if (retval)
				return -EFAULT;
			cdev->errcode = (*capifuncs->capi_get_manufacturer) (data.contr, data.manufacturer);
			if (cdev->errcode)
				return -EIO;

			retval = copy_to_user((void *) arg, (void *) data.manufacturer,
					      sizeof(data.manufacturer));
			if (retval)
				return -EFAULT;

		}
		return 0;
	case CAPI_GET_ERRCODE:
		data.errcode = cdev->errcode;
		cdev->errcode = CAPI_NOERROR;
		if (arg) {
			retval = copy_to_user((void *) arg,
					      (void *) &data.errcode,
					      sizeof(data.errcode));
			if (retval)
				return -EFAULT;
		}
		return data.errcode;

	case CAPI_INSTALLED:
		if ((*capifuncs->capi_installed) ())
			return 0;
		return -ENXIO;

	case CAPI_MANUFACTURER_CMD:
		{
			struct capi_manufacturer_cmd mcmd;
			if (minor)
				return -EINVAL;
			if (!capable(CAP_SYS_ADMIN))
				return -EPERM;
			retval = copy_from_user((void *) &mcmd, (void *) arg,
						sizeof(mcmd));
			if (retval)
				return -EFAULT;
			return (*capifuncs->capi_manufacturer) (mcmd.cmd, mcmd.data);
		}
		return 0;
	}
	return -EINVAL;
}

static int capi_open(struct inode *inode, struct file *file)
{
	unsigned int minor = MINOR(inode->i_rdev);

	if (minor >= CAPI_MAXMINOR)
		return -ENXIO;

	if (minor) {
		if (capidevs[minor].is_open)
			return -EEXIST;

		capidevs[minor].is_open = 1;
		skb_queue_head_init(&capidevs[minor].recv_queue);
		MOD_INC_USE_COUNT;

	} else {

		if (!capidevs[minor].is_open) {
			capidevs[minor].is_open = 1;
			MOD_INC_USE_COUNT;
		}
	}


	return 0;
}

static int
capi_release(struct inode *inode, struct file *file)
{
	unsigned int minor = MINOR(inode->i_rdev);
	struct capidev *cdev;
	struct sk_buff *skb;

	if (minor >= CAPI_MAXMINOR || !capidevs[minor].is_open) {
		printk(KERN_ERR "capi20: release minor %d ???\n", minor);
		return 0;
	}
	cdev = &capidevs[minor];

	if (minor) {

		if (cdev->is_registered)
			(*capifuncs->capi_release) (cdev->applid);

		cdev->is_registered = 0;
		cdev->applid = 0;

		while ((skb = skb_dequeue(&cdev->recv_queue)) != 0)
			kfree_skb(skb);
	}
	cdev->is_open = 0;

	MOD_DEC_USE_COUNT;
	return 0;
}

static struct file_operations capi_fops =
{
	capi_llseek,
	capi_read,
	capi_write,
	NULL,			/* capi_readdir */
	capi_poll,
	capi_ioctl,
	NULL,			/* capi_mmap */
	capi_open,
	capi_release,
	NULL,			/* capi_fsync */
	NULL,			/* capi_fasync */
};


/* -------- init function and module interface ---------------------- */

#ifdef MODULE
#define	 capi_init	init_module
#endif

static struct capi_interface_user cuser = {
	"capi20",
	0,
};

int capi_init(void)
{
	memset(capidevs, 0, sizeof(capidevs));

	if (register_chrdev(capi_major, "capi20", &capi_fops)) {
		printk(KERN_ERR "capi20: unable to get major %d\n", capi_major);
		return -EIO;
	}
	printk(KERN_NOTICE "capi20: started up with major %d\n", capi_major);

	if ((capifuncs = attach_capi_interface(&cuser)) == 0) {
		unregister_chrdev(capi_major, "capi20");
		return -EIO;
	}
	return 0;
}

#ifdef MODULE
void cleanup_module(void)
{
	unregister_chrdev(capi_major, "capi20");
	(void) detach_capi_interface(&cuser);
}

#endif
