/*********************************************************************************************************
** 函数名称: get_priv_descr_and_size
** 功能描述: Wrapper to call a private Wireless Extension handler.
** 输 入 :
** 输 出 : OK or ERROR
** 全局变量:
** 调用模块:
*********************************************************************************************************/
static int get_priv_descr_and_size (struct netif *dev, unsigned int cmd,
const struct iw_priv_args **descrp)
{
const struct iw_priv_args *descr;
int i, extra_size;
struct iw_handler_def *handlers = (struct iw_handler_def *)dev->wireless_handlers;
if (!handlers) {
return (-EOPNOTSUPP);
}
descr = NULL;
for (i = 0; i < handlers->num_private_args; i++) {
if (cmd == handlers->private_args[i].cmd) {
descr = &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);
}
/*
* 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 inline int ioctl_private_call(struct net_device * dev,
struct ifreq * ifr,
unsigned int cmd,
iw_handler handler)
{
struct iwreq * iwr = (struct iwreq *) ifr;
struct iw_priv_args * descr = NULL;
struct iw_request_info info;
int extra_size = 0;
int i;
int ret = -EINVAL;
/* Get the description of the IOCTL */
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;
}
#ifdef WE_IOCTL_DEBUG
printk(KERN_DEBUG "%s (WE) : Found private handler for 0x%04X\n",
ifr->ifr_name, cmd);
if(descr) {
printk(KERN_DEBUG "%s (WE) : Name %s, set %X, get %X\n",
dev->name, descr->name,
descr->set_args, descr->get_args);
}
#endif /* WE_IOCTL_DEBUG */
/* Compute the size of the set/get arguments */
if(descr != NULL) {
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 set 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;
}
}
/* Prepare the call */
info.cmd = cmd;
info.flags = 0;
/* 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 {
char * extra;
int err;
/* 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;
/* Does it fits within bounds ? */
if(iwr->u.data.length > (descr->set_args &
IW_PRIV_SIZE_MASK))
return -E2BIG;
} else {
/* Check NULL pointer */
if(iwr->u.data.pointer == NULL)
return -EFAULT;
}
#ifdef WE_IOCTL_DEBUG
printk(KERN_DEBUG "%s (WE) : Malloc %d bytes\n",
dev->name, extra_size);
#endif /* WE_IOCTL_DEBUG */
/* Always allocate for max space. Easier, and won't last
* long... */
extra = kmalloc(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,
extra_size);
if (err) {
kfree(extra);
return -EFAULT;
}
#ifdef WE_IOCTL_DEBUG
printk(KERN_DEBUG "%s (WE) : Got %d elem\n",
dev->name, iwr->u.data.length);
#endif /* WE_IOCTL_DEBUG */
}
/* Call the handler */
ret = handler(dev, &info, &(iwr->u), extra);
/* If we have something to return to the user */
if (!ret && IW_IS_GET(cmd)) {
err = copy_to_user(iwr->u.data.pointer, extra,
extra_size);
if (err)
ret = -EFAULT;
#ifdef WE_IOCTL_DEBUG
printk(KERN_DEBUG "%s (WE) : Wrote %d elem\n",
dev->name, iwr->u.data.length);
#endif /* WE_IOCTL_DEBUG */
}
/* Cleanup - I told you it wasn't that long ;-) */
kfree(extra);
}
/* Call commit handler if needed and defined */
if(ret == -EIWCOMMIT)
ret = call_commit_handler(dev);
return ret;
}
