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wext: Extract standard call iw_point handling into seperate function.
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Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller authored and David S. Miller committed Jun 17, 2008
1 parent 208887d commit 84149b0
Showing 1 changed file with 134 additions and 124 deletions.
258 changes: 134 additions & 124 deletions net/wireless/wext.c
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Original file line number Diff line number Diff line change
Expand Up @@ -694,6 +694,138 @@ void wext_proc_exit(struct net *net)
*/

/* ---------------------------------------------------------------- */
static int ioctl_standard_iw_point(struct iw_point *iwp, unsigned int cmd,
const struct iw_ioctl_description *descr,
iw_handler handler, struct net_device *dev,
struct iw_request_info *info)
{
int err, extra_size, user_length = 0, essid_compat = 0;
char *extra;

/* Calculate space needed by arguments. Always allocate
* for max space.
*/
extra_size = descr->max_tokens * descr->token_size;

/* Check need for ESSID compatibility for WE < 21 */
switch (cmd) {
case SIOCSIWESSID:
case SIOCGIWESSID:
case SIOCSIWNICKN:
case SIOCGIWNICKN:
if (iwp->length == descr->max_tokens + 1)
essid_compat = 1;
else if (IW_IS_SET(cmd) && (iwp->length != 0)) {
char essid[IW_ESSID_MAX_SIZE + 1];

err = copy_from_user(essid, iwp->pointer,
iwp->length *
descr->token_size);
if (err)
return -EFAULT;

if (essid[iwp->length - 1] == '\0')
essid_compat = 1;
}
break;
default:
break;
}

iwp->length -= essid_compat;

/* Check what user space is giving us */
if (IW_IS_SET(cmd)) {
/* Check NULL pointer */
if (!iwp->pointer && iwp->length != 0)
return -EFAULT;
/* Check if number of token fits within bounds */
if (iwp->length > descr->max_tokens)
return -E2BIG;
if (iwp->length < descr->min_tokens)
return -EINVAL;
} else {
/* Check NULL pointer */
if (!iwp->pointer)
return -EFAULT;
/* Save user space buffer size for checking */
user_length = iwp->length;

/* Don't check if user_length > max to allow forward
* compatibility. The test user_length < min is
* implied by the test at the end.
*/

/* Support for very large requests */
if ((descr->flags & IW_DESCR_FLAG_NOMAX) &&
(user_length > descr->max_tokens)) {
/* Allow userspace to GET more than max so
* we can support any size GET requests.
* There is still a limit : -ENOMEM.
*/
extra_size = user_length * descr->token_size;

/* Note : user_length is originally a __u16,
* and token_size is controlled by us,
* so extra_size won't get negative and
* won't overflow...
*/
}
}

/* kzalloc() ensures NULL-termination for essid_compat. */
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,
iwp->length *
descr->token_size)) {
err = -EFAULT;
goto out;
}
}

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

iwp->length += essid_compat;

/* If we have something to return to the user */
if (!err && IW_IS_GET(cmd)) {
/* Check if there is enough buffer up there */
if (user_length < iwp->length) {
err = -E2BIG;
goto out;
}

if (copy_to_user(iwp->pointer, extra,
iwp->length *
descr->token_size)) {
err = -EFAULT;
goto out;
}
}

/* Generate an event to notify listeners of the change */
if ((descr->flags & IW_DESCR_FLAG_EVENT) && err == -EIWCOMMIT) {
union iwreq_data *data = (union iwreq_data *) iwp;

if (descr->flags & IW_DESCR_FLAG_RESTRICT)
/* If the event is restricted, don't
* export the payload.
*/
wireless_send_event(dev, cmd, data, NULL);
else
wireless_send_event(dev, cmd, data, extra);
}

out:
kfree(extra);
return err;
}

/*
* Wrapper to call a standard Wireless Extension handler.
* We do various checks and also take care of moving data between
Expand Down Expand Up @@ -729,130 +861,8 @@ static int ioctl_standard_call(struct net_device * dev,
((ret == 0) || (ret == -EIWCOMMIT)))
wireless_send_event(dev, cmd, &(iwr->u), NULL);
} else {
char * extra;
int extra_size;
int user_length = 0;
int err;
int essid_compat = 0;

/* Calculate space needed by arguments. Always allocate
* for max space. Easier, and won't last long... */
extra_size = descr->max_tokens * descr->token_size;

/* Check need for ESSID compatibility for WE < 21 */
switch (cmd) {
case SIOCSIWESSID:
case SIOCGIWESSID:
case SIOCSIWNICKN:
case SIOCGIWNICKN:
if (iwr->u.data.length == descr->max_tokens + 1)
essid_compat = 1;
else if (IW_IS_SET(cmd) && (iwr->u.data.length != 0)) {
char essid[IW_ESSID_MAX_SIZE + 1];

err = copy_from_user(essid, iwr->u.data.pointer,
iwr->u.data.length *
descr->token_size);
if (err)
return -EFAULT;

if (essid[iwr->u.data.length - 1] == '\0')
essid_compat = 1;
}
break;
default:
break;
}

iwr->u.data.length -= essid_compat;

/* Check what user space is giving us */
if (IW_IS_SET(cmd)) {
/* Check NULL pointer */
if ((iwr->u.data.pointer == NULL) &&
(iwr->u.data.length != 0))
return -EFAULT;
/* Check if number of token fits within bounds */
if (iwr->u.data.length > descr->max_tokens)
return -E2BIG;
if (iwr->u.data.length < descr->min_tokens)
return -EINVAL;
} else {
/* Check NULL pointer */
if (iwr->u.data.pointer == NULL)
return -EFAULT;
/* Save user space buffer size for checking */
user_length = iwr->u.data.length;

/* Don't check if user_length > max to allow forward
* compatibility. The test user_length < min is
* implied by the test at the end. */

/* Support for very large requests */
if ((descr->flags & IW_DESCR_FLAG_NOMAX) &&
(user_length > descr->max_tokens)) {
/* Allow userspace to GET more than max so
* we can support any size GET requests.
* There is still a limit : -ENOMEM. */
extra_size = user_length * descr->token_size;
/* Note : user_length is originally a __u16,
* and token_size is controlled by us,
* so extra_size won't get negative and
* won't overflow... */
}
}

/* Create the kernel buffer */
/* kzalloc ensures NULL-termination for essid_compat */
extra = kzalloc(extra_size, GFP_KERNEL);
if (extra == NULL)
return -ENOMEM;

/* If it is a SET, get all the extra data in here */
if (IW_IS_SET(cmd) && (iwr->u.data.length != 0)) {
err = copy_from_user(extra, iwr->u.data.pointer,
iwr->u.data.length *
descr->token_size);
if (err) {
kfree(extra);
return -EFAULT;
}
}

/* Call the handler */
ret = handler(dev, &info, &(iwr->u), extra);

iwr->u.data.length += essid_compat;

/* If we have something to return to the user */
if (!ret && IW_IS_GET(cmd)) {
/* Check if there is enough buffer up there */
if (user_length < iwr->u.data.length) {
kfree(extra);
return -E2BIG;
}

err = copy_to_user(iwr->u.data.pointer, extra,
iwr->u.data.length *
descr->token_size);
if (err)
ret = -EFAULT;
}

/* Generate an event to notify listeners of the change */
if ((descr->flags & IW_DESCR_FLAG_EVENT) &&
((ret == 0) || (ret == -EIWCOMMIT))) {
if (descr->flags & IW_DESCR_FLAG_RESTRICT)
/* If the event is restricted, don't
* export the payload */
wireless_send_event(dev, cmd, &(iwr->u), NULL);
else
wireless_send_event(dev, cmd, &(iwr->u),
extra);
}

/* Cleanup - I told you it wasn't that long ;-) */
kfree(extra);
ret = ioctl_standard_iw_point(&iwr->u.data, cmd, descr,
handler, dev, &info);
}

/* Call commit handler if needed and defined */
Expand Down

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