iwpriv工具通过ioctl动态获取相应无线网卡驱动的private_args所有扩展参数 收藏
分类： Linux 2010-02-26 17:29 485人阅读 评论(1) 收藏 举报
扩展工具cmdstructsocketstreamiwpriv工具通过ioctl动态获取相应无线网卡驱动的private_args所有扩展参数 收藏

iwpriv工具通过ioctl动态获取相应无线网卡驱动的private_args所有扩展参数

iwpriv是处理下面的wlan_private_args的所有扩展命令,iwpriv的实现上,是这样的,
=>main
=>set_private
=>iw_get_priv_info获取wireless网卡所能处理的所有wlan_private_args类型.

dev_ioctl
=>wext_handle_ioctl
=>wireless_process_ioctl
if (cmd == SIOCGIWPRIV && dev->wireless_handlers)
return ioctl_standard_call(dev, ifr, cmd,
&iw_handler_get_private);
static int ioctl_standard_call(struct net_device * dev,
struct ifreq * ifr,
unsigned int cmd,
iw_handler handler)
{
...
/* Call the handler */
ret = handler(dev, &info, &(iwr->u), extra);
if (user_length < iwr->u.data.length) {
kfree(extra);
return -E2BIG;
//通知iwpriv,本wifi网卡对应的private命令还没有完,还有,这样iwpriv将会继续
//maxpriv默认为16,即将以16个为一组,一组一组的从wifi网卡驱动读取该网卡所能支持的所有private_args参数
//newpriv = realloc(priv, maxpriv * sizeof(priv[0]));继续申请,继续拷贝,知道将wifi网卡自定义的wlan_private_args参数全部
//传出到iwpriv为止.
}
...
}
/* New driver API : try to find the handler */
handler = get_handler(dev, cmd);//获取

if (handler) {
/* Standard and private are not the same */
if (cmd < SIOCIWFIRSTPRIV)
return ioctl_standard_call(dev, ifr, cmd, handler);
else

//如果有对应的handler,那么处理iwpriv的命令,可以我们的iwpriv都是由dev->do_ioctl完成的.
return ioctl_private_call(dev, ifr, cmd, handler);
}
/* Old driver API : call driver ioctl handler */
if (dev->do_ioctl)
//如果dev->wireless_handlers->standard和dev->wireless_handlers->private[index都不对该cmd作处理,那么由
//dev->do_ioctl = wlan_do_ioctl;我们驱动的最后处理函数wlan_do_ioctl处理.
return dev->do_ioctl(dev, ifr, cmd);

static iw_handler get_handler(struct net_device *dev, unsigned int cmd)
{
/* Don't "optimise" the following variable, it will crash */
unsigned int index; /* *MUST* be unsigned */

/* Check if we have some wireless handlers defined */
if (dev->wireless_handlers == NULL)
return NULL;

/* Try as a standard command */
index = cmd - SIOCIWFIRST;
if (ind
ex < dev->wireless_handlers->num_standard)
return dev->wireless_handlers->standard[index];

/* Try as a private command */
in