net/wireless/wext-priv.c - third_party/linux - Git at Google

 /*
  * This file implement the Wireless Extensions priv API.
  *
  * Authors :	Jean Tourrilhes - HPL - <jt@hpl.hp.com>
  * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
  * Copyright	2009 Johannes Berg <johannes@sipsolutions.net>
  *
  * (As all part of the Linux kernel, this file is GPL)
  */
 #include <linux/slab.h>
 #include <linux/wireless.h>
 #include <linux/netdevice.h>
 #include <net/iw_handler.h>
 #include <net/wext.h>

 int iw_handler_get_private(struct net_device *		dev,
 			   struct iw_request_info *	info,
 			   union iwreq_data *		wrqu,
 			   char *			extra)
 {
 	/* Check if the driver has something to export */
 	if ((dev->wireless_handlers->num_private_args == 0) ||
 	   (dev->wireless_handlers->private_args == NULL))
 		return -EOPNOTSUPP;

 	/* Check if there is enough buffer up there */
 	if (wrqu->data.length < dev->wireless_handlers->num_private_args) {
 		/* User space can't know in advance how large the buffer
 		 * needs to be. Give it a hint, so that we can support
 		 * any size buffer we want somewhat efficiently... */
 		wrqu->data.length = dev->wireless_handlers->num_private_args;
 		return -E2BIG;
 	}

 	/* Set the number of available ioctls. */
 	wrqu->data.length = dev->wireless_handlers->num_private_args;

 	/* Copy structure to the user buffer. */
 	memcpy(extra, dev->wireless_handlers->private_args,
 	       sizeof(struct iw_priv_args) * wrqu->data.length);

 	return 0;
 }

 /* Size (in bytes) of the various private data types */
 static const char iw_priv_type_size[] = {
 	0,				/* IW_PRIV_TYPE_NONE */
 	1,				/* IW_PRIV_TYPE_BYTE */
 	1,				/* IW_PRIV_TYPE_CHAR */
 	0,				/* Not defined */
 	sizeof(__u32),			/* IW_PRIV_TYPE_INT */
 	sizeof(struct iw_freq),		/* IW_PRIV_TYPE_FLOAT */
 	sizeof(struct sockaddr),	/* IW_PRIV_TYPE_ADDR */
 	0,				/* Not defined */
 };

 static int get_priv_size(__u16 args)
 {
 	int	num = args & IW_PRIV_SIZE_MASK;
 	int	type = (args & IW_PRIV_TYPE_MASK) >> 12;

 	return num * iw_priv_type_size[type];
 }

 static int adjust_priv_size(__u16 args, struct iw_point *iwp)
 {
 	int	num = iwp->length;
 	int	max = args & IW_PRIV_SIZE_MASK;
 	int	type = (args & IW_PRIV_TYPE_MASK) >> 12;

 	/* Make sure the driver doesn't goof up */
 	if (max < num)
 		num = max;

 	return num * iw_priv_type_size[type];
 }

 /*
  * Wrapper to call a private Wireless Extension handler.
  * We do various checks and also take care of moving data between
  * user space and kernel space.
  * It's not as nice and slimline as the standard wrapper. The cause
  * is struct iw_priv_args, which was not really designed for the
  * job we are going here.
  *
  * IMPORTANT : This function prevent to set and get data on the same
  * IOCTL and enforce the SET/GET convention. Not doing it would be
  * far too hairy...
  * If you need to set and get data at the same time, please don't use
  * a iw_handler but process it in your ioctl handler (i.e. use the
  * old driver API).
  */
 static int get_priv_descr_and_size(struct net_device *dev, unsigned int cmd,
 				   const struct iw_priv_args **descrp)
 {
 	const struct iw_priv_args *descr;
 	int i, extra_size;

 	descr = NULL;
 	for (i = 0; i < dev->wireless_handlers->num_private_args; i++) {
 		if (cmd == dev->wireless_handlers->private_args[i].cmd) {
 			descr = &dev->wireless_handlers->private_args[i];
 			break;
 		}
 	}

 	extra_size = 0;
 	if (descr) {
 		if (IW_IS_SET(cmd)) {
 			int	offset = 0;	/* For sub-ioctls */
 			/* Check for sub-ioctl handler */
 			if (descr->name[0] == '\0')
 				/* Reserve one int for sub-ioctl index */
 				offset = sizeof(__u32);

 			/* Size of set arguments */
 			extra_size = get_priv_size(descr->set_args);

 			/* Does it fits in iwr ? */
 			if ((descr->set_args & IW_PRIV_SIZE_FIXED) &&
 			   ((extra_size + offset) <= IFNAMSIZ))
 				extra_size = 0;
 		} else {
 			/* Size of get arguments */
 			extra_size = get_priv_size(descr->get_args);

 			/* Does it fits in iwr ? */
 			if ((descr->get_args & IW_PRIV_SIZE_FIXED) &&
 			   (extra_size <= IFNAMSIZ))
 				extra_size = 0;
 		}
 	}
 	*descrp = descr;
 	return extra_size;
 }

 static int ioctl_private_iw_point(struct iw_point *iwp, unsigned int cmd,
 				  const struct iw_priv_args *descr,
 				  iw_handler handler, struct net_device *dev,
 				  struct iw_request_info *info, int extra_size)
 {
 	char *extra;
 	int err;

 	/* Check what user space is giving us */
 	if (IW_IS_SET(cmd)) {
 		if (!iwp->pointer && iwp->length != 0)
 			return -EFAULT;

 		if (iwp->length > (descr->set_args & IW_PRIV_SIZE_MASK))
 			return -E2BIG;
 	} else if (!iwp->pointer)
 		return -EFAULT;

 	extra = kzalloc(extra_size, GFP_KERNEL);
 	if (!extra)
 		return -ENOMEM;

 	/* If it is a SET, get all the extra data in here */
 	if (IW_IS_SET(cmd) && (iwp->length != 0)) {
 		if (copy_from_user(extra, iwp->pointer, extra_size)) {
 			err = -EFAULT;
 			goto out;
 		}
 	}

 	/* Call the handler */
 	err = handler(dev, info, (union iwreq_data *) iwp, extra);

 	/* If we have something to return to the user */
 	if (!err && IW_IS_GET(cmd)) {
 		/* Adjust for the actual length if it's variable,
 		 * avoid leaking kernel bits outside.
 		 */
 		if (!(descr->get_args & IW_PRIV_SIZE_FIXED))
 			extra_size = adjust_priv_size(descr->get_args, iwp);

 		if (copy_to_user(iwp->pointer, extra, extra_size))
 			err =  -EFAULT;
 	}

 out:
 	kfree(extra);
 	return err;
 }

 int ioctl_private_call(struct net_device *dev, struct iwreq *iwr,
 		       unsigned int cmd, struct iw_request_info *info,
 		       iw_handler handler)
 {
 	int extra_size = 0, ret = -EINVAL;
 	const struct iw_priv_args *descr;

 	extra_size = get_priv_descr_and_size(dev, cmd, &descr);

 	/* Check if we have a pointer to user space data or not. */
 	if (extra_size == 0) {
 		/* No extra arguments. Trivial to handle */
 		ret = handler(dev, info, &(iwr->u), (char *) &(iwr->u));
 	} else {
 		ret = ioctl_private_iw_point(&iwr->u.data, cmd, descr,
 					     handler, dev, info, extra_size);
 	}

 	/* Call commit handler if needed and defined */
 	if (ret == -EIWCOMMIT)
 		ret = call_commit_handler(dev);

 	return ret;
 }

 #ifdef CONFIG_COMPAT
 int compat_private_call(struct net_device *dev, struct iwreq *iwr,
 			unsigned int cmd, struct iw_request_info *info,
 			iw_handler handler)
 {
 	const struct iw_priv_args *descr;
 	int ret, extra_size;

 	extra_size = get_priv_descr_and_size(dev, cmd, &descr);

 	/* Check if we have a pointer to user space data or not. */
 	if (extra_size == 0) {
 		/* No extra arguments. Trivial to handle */
 		ret = handler(dev, info, &(iwr->u), (char *) &(iwr->u));
 	} else {
 		struct compat_iw_point *iwp_compat;
 		struct iw_point iwp;

 		iwp_compat = (struct compat_iw_point *) &iwr->u.data;
 		iwp.pointer = compat_ptr(iwp_compat->pointer);
 		iwp.length = iwp_compat->length;
 		iwp.flags = iwp_compat->flags;

 		ret = ioctl_private_iw_point(&iwp, cmd, descr,
 					     handler, dev, info, extra_size);

 		iwp_compat->pointer = ptr_to_compat(iwp.pointer);
 		iwp_compat->length = iwp.length;
 		iwp_compat->flags = iwp.flags;
 	}

 	/* Call commit handler if needed and defined */
 	if (ret == -EIWCOMMIT)
 		ret = call_commit_handler(dev);

 	return ret;
 }
 #endif
	/*
	* This file implement the Wireless Extensions priv API.
	*
	* Authors : Jean Tourrilhes - HPL - <jt@hpl.hp.com>
	* Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved.
	* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
	*
	* (As all part of the Linux kernel, this file is GPL)
	*/
	#include <linux/slab.h>
	#include <linux/wireless.h>
	#include <linux/netdevice.h>
	#include <net/iw_handler.h>
	#include <net/wext.h>

	int iw_handler_get_private(struct net_device * dev,
	struct iw_request_info * info,
	union iwreq_data * wrqu,
	char * extra)
	{
	/* Check if the driver has something to export */
	if ((dev->wireless_handlers->num_private_args == 0) \|\|
	(dev->wireless_handlers->private_args == NULL))
	return -EOPNOTSUPP;

	/* Check if there is enough buffer up there */
	if (wrqu->data.length < dev->wireless_handlers->num_private_args) {
	/* User space can't know in advance how large the buffer
	* needs to be. Give it a hint, so that we can support
	* any size buffer we want somewhat efficiently... */
	wrqu->data.length = dev->wireless_handlers->num_private_args;
	return -E2BIG;
	}

	/* Set the number of available ioctls. */
	wrqu->data.length = dev->wireless_handlers->num_private_args;

	/* Copy structure to the user buffer. */
	memcpy(extra, dev->wireless_handlers->private_args,
	sizeof(struct iw_priv_args) * wrqu->data.length);

	return 0;
	}

	/* Size (in bytes) of the various private data types */
	static const char iw_priv_type_size[] = {
	0, /* IW_PRIV_TYPE_NONE */
	1, /* IW_PRIV_TYPE_BYTE */
	1, /* IW_PRIV_TYPE_CHAR */
	0, /* Not defined */
	sizeof(__u32), /* IW_PRIV_TYPE_INT */
	sizeof(struct iw_freq), /* IW_PRIV_TYPE_FLOAT */
	sizeof(struct sockaddr), /* IW_PRIV_TYPE_ADDR */
	0, /* Not defined */
	};

	static int get_priv_size(__u16 args)
	{
	int num = args & IW_PRIV_SIZE_MASK;
	int type = (args & IW_PRIV_TYPE_MASK) >> 12;

	return num * iw_priv_type_size[type];
	}

	static int adjust_priv_size(__u16 args, struct iw_point *iwp)
	{
	int num = iwp->length;
	int max = args & IW_PRIV_SIZE_MASK;
	int type = (args & IW_PRIV_TYPE_MASK) >> 12;

	/* Make sure the driver doesn't goof up */
	if (max < num)
	num = max;

	return num * iw_priv_type_size[type];
	}

	/*
	* Wrapper to call a private Wireless Extension handler.
	* We do various checks and also take care of moving data between
	* user space and kernel space.
	* It's not as nice and slimline as the standard wrapper. The cause
	* is struct iw_priv_args, which was not really designed for the
	* job we are going here.
	*
	* IMPORTANT : This function prevent to set and get data on the same
	* IOCTL and enforce the SET/GET convention. Not doing it would be
	* far too hairy...
	* If you need to set and get data at the same time, please don't use
	* a iw_handler but process it in your ioctl handler (i.e. use the
	* old driver API).
	*/
	static int get_priv_descr_and_size(struct net_device *dev, unsigned int cmd,
	const struct iw_priv_args **descrp)
	{
	const struct iw_priv_args *descr;
	int i, extra_size;

	descr = NULL;
	for (i = 0; i < dev->wireless_handlers->num_private_args; i++) {
	if (cmd == dev->wireless_handlers->private_args[i].cmd) {
	descr = &dev->wireless_handlers->private_args[i];
	break;
	}
	}

	extra_size = 0;
	if (descr) {
	if (IW_IS_SET(cmd)) {
	int offset = 0; /* For sub-ioctls */
	/* Check for sub-ioctl handler */
	if (descr->name[0] == '\0')
	/* Reserve one int for sub-ioctl index */
	offset = sizeof(__u32);

	/* Size of set arguments */
	extra_size = get_priv_size(descr->set_args);

	/* Does it fits in iwr ? */
	if ((descr->set_args & IW_PRIV_SIZE_FIXED) &&
	((extra_size + offset) <= IFNAMSIZ))
	extra_size = 0;
	} else {
	/* Size of get arguments */
	extra_size = get_priv_size(descr->get_args);

	/* Does it fits in iwr ? */
	if ((descr->get_args & IW_PRIV_SIZE_FIXED) &&
	(extra_size <= IFNAMSIZ))
	extra_size = 0;
	}
	}
	*descrp = descr;
	return extra_size;
	}

	static int ioctl_private_iw_point(struct iw_point *iwp, unsigned int cmd,
	const struct iw_priv_args *descr,
	iw_handler handler, struct net_device *dev,
	struct iw_request_info *info, int extra_size)
	{
	char *extra;
	int err;

	/* Check what user space is giving us */
	if (IW_IS_SET(cmd)) {
	if (!iwp->pointer && iwp->length != 0)
	return -EFAULT;

	if (iwp->length > (descr->set_args & IW_PRIV_SIZE_MASK))
	return -E2BIG;
	} else if (!iwp->pointer)
	return -EFAULT;

	extra = kzalloc(extra_size, GFP_KERNEL);
	if (!extra)
	return -ENOMEM;

	/* If it is a SET, get all the extra data in here */
	if (IW_IS_SET(cmd) && (iwp->length != 0)) {
	if (copy_from_user(extra, iwp->pointer, extra_size)) {
	err = -EFAULT;
	goto out;
	}
	}

	/* Call the handler */
	err = handler(dev, info, (union iwreq_data *) iwp, extra);

	/* If we have something to return to the user */
	if (!err && IW_IS_GET(cmd)) {
	/* Adjust for the actual length if it's variable,
	* avoid leaking kernel bits outside.
	*/
	if (!(descr->get_args & IW_PRIV_SIZE_FIXED))
	extra_size = adjust_priv_size(descr->get_args, iwp);

	if (copy_to_user(iwp->pointer, extra, extra_size))
	err = -EFAULT;
	}

	out:
	kfree(extra);
	return err;
	}

	int ioctl_private_call(struct net_device dev, struct iwreq iwr,
	unsigned int cmd, struct iw_request_info *info,
	iw_handler handler)
	{
	int extra_size = 0, ret = -EINVAL;
	const struct iw_priv_args *descr;

	extra_size = get_priv_descr_and_size(dev, cmd, &descr);

	/* Check if we have a pointer to user space data or not. */
	if (extra_size == 0) {
	/* No extra arguments. Trivial to handle */
	ret = handler(dev, info, &(iwr->u), (char *) &(iwr->u));
	} else {
	ret = ioctl_private_iw_point(&iwr->u.data, cmd, descr,
	handler, dev, info, extra_size);
	}

	/* Call commit handler if needed and defined */
	if (ret == -EIWCOMMIT)
	ret = call_commit_handler(dev);

	return ret;
	}

	#ifdef CONFIG_COMPAT
	int compat_private_call(struct net_device dev, struct iwreq iwr,
	unsigned int cmd, struct iw_request_info *info,
	iw_handler handler)
	{
	const struct iw_priv_args *descr;
	int ret, extra_size;

	extra_size = get_priv_descr_and_size(dev, cmd, &descr);

	/* Check if we have a pointer to user space data or not. */
	if (extra_size == 0) {
	/* No extra arguments. Trivial to handle */
	ret = handler(dev, info, &(iwr->u), (char *) &(iwr->u));
	} else {
	struct compat_iw_point *iwp_compat;
	struct iw_point iwp;

	iwp_compat = (struct compat_iw_point *) &iwr->u.data;
	iwp.pointer = compat_ptr(iwp_compat->pointer);
	iwp.length = iwp_compat->length;
	iwp.flags = iwp_compat->flags;

	ret = ioctl_private_iw_point(&iwp, cmd, descr,
	handler, dev, info, extra_size);

	iwp_compat->pointer = ptr_to_compat(iwp.pointer);
	iwp_compat->length = iwp.length;
	iwp_compat->flags = iwp.flags;
	}

	/* Call commit handler if needed and defined */
	if (ret == -EIWCOMMIT)
	ret = call_commit_handler(dev);

	return ret;
	}
	#endif