diff options
Diffstat (limited to 'net/wireless/wext-priv.c')
| -rw-r--r-- | net/wireless/wext-priv.c | 248 | 
1 files changed, 248 insertions, 0 deletions
diff --git a/net/wireless/wext-priv.c b/net/wireless/wext-priv.c new file mode 100644 index 00000000000..a3c2277de9e --- /dev/null +++ b/net/wireless/wext-priv.c @@ -0,0 +1,248 @@ +/* + * 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/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 = kmalloc(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  |