centos7 netfilter过滤程序

windows客户端上安装vscode和putty。

我纯粹是把vscode作为一个远程书写工具。编译工作是通过putty在服务器中执行make命令完成。因此我的vscode只安装了SSH插件和C/C++插件。为了让vscode在书写C/C++代码有智能提示，我在vscode配置文件c_cpp_properties.json中添加了头文件路径：

{
    "configurations": [
        {
            "name": "Linux",
            "includePath": [
                "${workspaceFolder}
MODULE_LICENSE("Dual BSD/GPL");
 
 
static unsigned int nf_hook_out(unsigned int hooknum,
  struct sk_buff *skb,
  const struct net_device *in,
  const struct net_device *out,
  int (*okfn)(struct sk_buff*))
{
	struct sk_buff *sk = skb;
	struct iphdr *iph=ip_hdr(sk);

	now = current_kernel_time();

	if(iph->protocol==IPPROTO_ICMP)
	{
		if(now.tv_sec - start.tv_sec < 600){
			return NF_DROP;
		}
		else{
			return NF_ACCEPT;
		}
		
	}else
	{
		return NF_ACCEPT;
	}
}
 
 
static struct nf_hook_ops nfout=
{
	.list = {NULL,NULL},
	.hook = nf_hook_out,
	.hooknum = NF_INET_LOCAL_OUT,
	.pf = PF_INET,
	.priority = NF_IP_PRI_FIRST
};
 

static int __init banping_init(void)
{
	nf_register_hook(&nfout);
    start = current_kernel_time();
	printk(KERN_ALERT"Banping module init%ldn",start.tv_sec);
	return 0;
}

static void __exit banping_exit(void)
{
	nf_unregister_hook(&nfout);
	printk(KERN_ALERT"Banping module exitn");
}
module_init(banping_init);
module_exit(banping_exit);
 
MODULE_AUTHOR("FEI FENG");
MODULE_DESCRIPTION("Ban ping");
MODULE_VERSION("0.0.1");

CONFIG_MODULE_SIG=n
KERNELDIR :=/usr/src/kernels/3.10.0-1160.15.2.el7.x86_64
 
CURRENT_PATH :=$(shell pwd)

obj-m := netflt.o
 
build:kernel_modules
 
kernel_modules:
 
	$(MAKE) -C $(KERNELDIR) M=$(CURRENT_PATH) modules
 
clean:
 
	$(MAKE) -C $(KERNELDIR) M=$(CURRENT_PATH) clean