linux - 试图阅读 iw_statistics 但代码不起作用？

Question

我需要从 iw_statistics 结构中读取某些统计信息，代码如下:

struct net_device *dev;
struct iw_statistics *wi_stats;
dev = first_net_device(&init_net);

  while (dev)
    {
      if (strncmp(dev->name , "wlan",4)==0 )
      {
         if (dev->wireless_handlers->get_wireless_stats(dev) !=NULL ) // <--- here's where the code crashes.
         {
        wi_stats = dev-wireless_handlers->get_wireless_stats(dev);
        printk(KERN_INFO "wi_stats = dev-wireless_handlers->get_wireless_stats(dev); worked!!! :D\n"); 
         }
       }

    }

我正在研究 linux 内核 2.6.35，并且正在编写一个内核模块。我在这里做错了什么？

Answer 1

看起来 wireless_handlers 结构是 Null ...仅仅因为网络设备的 name 字段已填充并不意味着它已配置。

这是设置 wireless_handlers 的地方:

#ifdef CONFIG_WIRELESS_EXT
    /* List of functions to handle Wireless Extensions (instead of ioctl).
     * See <net/iw_handler.h> for details. Jean II */
    const struct iw_handler_def *   wireless_handlers;
    /* Instance data managed by the core of Wireless Extensions. */
    struct iw_public_data * wireless_data;
#endif

您应该检查名为 CONFIG_WIRELESS_EXT 的值，如果它未设置，wireless_handler 结构未设置，因此您将指向一个 Null 你的模块会卡住