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/*
* 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
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