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.docxVIP

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){????/* Dont 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;???