/* detailed rx_errors: */
__u64 rx_length_errors;
__u64 rx_over_errors; /* receiver ring buff overflow */
__u64 rx_crc_errors; /* recved pkt with crc error */
__u64 rx_frame_errors; /* recv'd frame alignment error */
__u64 rx_fifo_errors; /* recv'r fifo overrun */
__u64 rx_missed_errors; /* receiver missed packet */
/* detailed tx_errors */
__u64 tx_aborted_errors;
__u64 tx_carrier_errors;
__u64 tx_fifo_errors;
__u64 tx_heartbeat_errors;
__u64 tx_window_errors;
/* for cslip etc */
__u64 rx_compressed;
__u64 tx_compressed;
};
主要是这四个成员
stats->rx_packets = packets;
stats->tx_packets = packets;
stats->rx_bytes = bytes;
stats->tx_bytes = bytes;
。实际上自己可以重写这个获取状态的函数，因为struct net_device *dev有一个成员就是struct net_device_stats stats;所以可以在重写的时候定义一个struct net_device_stats stats指向形参传递进来的回环网卡结构体的stats成员，同样只需要注意stats成员的上述四个成员即可。
9.在退出该驱动的时候就是取消注册结构体。达到注销网卡的目的。
static __net_exit void loopback_net_exit(struct net *net)
{
struct net_device *dev = net->loopback_dev;
unregister_netdev(dev);
}
下面为范例代码
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/in.h>
#include <linux/init.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <net/sock.h>
#include <net/checksum.h>
#include <linux/if_ether.h> /* For the statistics structure. */
#include <linux/if_arp.h> /* For ARPHRD_ETHER */
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/percpu.h>
#include <net/net_namespace.h>
#include <linux/u64_stats_sync.h>
unsigned long packets = 0;
unsigned long bytes = 0;
//struct net_device *dev;
static __net_exit void loopback_net_exit(struct net *net)
{
struct net_device *dev = net->loopback_dev;
unregister_netdev(dev);
}
static int loopback_net_xmit(struct sk_buff *skb,struct net_device *dev)
{
skb->protocol = eth_type_trans(skb,dev);
packets++;
bytes += skb->len;
netif_rx(skb);
return 0;
}
static struct net_device_stats *loopback_get_stats(struct net_device *dev)
{
struct net_device_stats *stats = &dev->stats;
stats->rx_packets = packets;
stats->tx_packets = packets;
stats->rx_bytes = bytes;
stats->tx_bytes = bytes;
return stats;
}
static const struct net_device_ops loopback_ops =
{
.ndo_start_xmit = loopback_net_xmit,
.ndo_get_stats = loopback_get_stats,
};