#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/ip.h>
#include <uapi/linux/netfilter_ipv4.h>
#include <uapi/linux/ip.h>
#include <net/netlink.h>
#include <net/net_namespace.h>

#include "../netlink_api/libnetlink_k.h"
#include "../../../Common/commuapinl.h"
#define strict_strtoul kstrtoul 

/**************************************************************************************************************/
#include <linux/rtnetlink.h>
#define NLMSG_TAIL(nmsg) \
	((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
#define RTA_LENGTH(len)	(RTA_ALIGN(sizeof(struct rtattr)) + (len))
#define RTA_ALIGNTO	4U
#define RTA_ALIGN(len) ( ((len)+RTA_ALIGNTO-1) & ~(RTA_ALIGNTO-1) )
struct policyconfmsg {
	__u8	policy_id;
};
/**************************************************************************************************************/

//int nf_nlmsg_multicast(struct netlinkk_cfg *g_nlcfg, struct sk_buff *skb);
unsigned int pdelivery_hook_func(void *priv,
			       struct sk_buff *skb,
			       const struct nf_hook_state *state);
//int debugfs_pkt_num_stati(struct netlinkk_cfg *g_nlcfg, struct nlmsghdr *nlh);



struct netlinkk_cfg g_nlcfg = {0};


static struct nf_hook_ops upm_nfho = {
  .hook = pdelivery_hook_func,
  .hooknum = 1, 			/* should be NF_IP_FORWARD,use NF_IP_LOCAL_IN=1 for test */
  .pf = PF_INET,
  .priority = NF_IP_PRI_FILTER,
};


int pdeliv_rcv_stat(struct sk_buff *skb, struct nlmsghdr *nlh)
{
	printk(KERN_INFO "pdeliv_rcv_stat, From: %d\n", nlh->nlmsg_pid);

	/**************************************************************************************************************/
	char *pload;
	struct nlattr *rta;
	char* load;
	unsigned long fk_type;

	pload = nlmsg_data(nlh) + NLMSG_ALIGN(sizeof(struct policyconfmsg));
	rta = (struct nlattr *)pload;
	load = RTA_DATA(rta);
	
	printk("***************************rta->nla_type=%d********************\n", rta->nla_type); //nla_type	
	printk("**************************load=*****%s**********\n",(char *)load);  //string printf
	strict_strtoul(load, 10, &fk_type); 
	printk("***************************fk_type%d********************\n", fk_type);
	/**************************************************************************************************************/

	/**************************************************************************************************************/

	switch(nlh->nlmsg_type)
	{
        //case COMMNMSG_POLICYCONF:/**/
		case NLMSG_DEBUGFS:
			if(nlh->nlmsg_type == NLMSG_DEBUGFS)
			{
				debugfs_pkt_num_stati(&g_nlcfg, nlh, fk_type);
				printk("*****************biduichengong********%d*******\n", nlh->nlmsg_type);
				return 0;
			}
            		break;

        	default:
			printk(KERN_INFO "libnetlink Unknow msgtype recieved!\n");
			return 0;
    }
	/**************************************************************************************************************/
	
	return 0;
}


int __init pdelivery_init(void)
{		
	int ret = -1;
	
	printk(KERN_CRIT "nl_upm initialed ok!\n");

	/*init for pdelivery module*/
	g_nlcfg.groups = PDELIVERY_NLGRP_MAX;
	g_nlcfg.subscriptions = NETLINK_PDELIVERY;
	//g_nlcfg.cfg.input = libnetlink_rcv;


	ret = libnetlinkk_init_byproto(&g_nlcfg);
	if(ret < 0)
	{
		printk (KERN_CRIT "pdelivery_init netlink init fail!.\n");
		return ret;
	}

	/*init the netfilter hook for upm*/
	printk (KERN_INFO "upm register netfilter module.\n");
	nf_register_net_hook (&init_net,&upm_nfho);

	/*do msg process register*/
	pdeliv_msgtype_register(PDNLGRP_REQUEST,pdeliv_rcv_stat,NULL,NULL);
	pdeliv_msgtype_register(NLMSG_DEBUGFS,pdeliv_rcv_stat,NULL,NULL);

	return 0;
}

void __exit pdelivery_exit(void)
{
    printk(KERN_CRIT "nl_upm existing...\n");
    libnetlinkk_exit(&g_nlcfg);

	/*init the netfilter hook for upm*/
	printk (KERN_INFO "upm unregister netfilter module.\n");
	nf_unregister_net_hook (&init_net,&upm_nfho);

	return;
}


/****************************************************************/
/*函数功能：pdelivery模块注册的netfilter钩子回调函数，用于从 */
/*netfilter框架接收到报文，然后调用netlink发送接口将报文上送到*/
/*用户态。报文内容从链路层头开始。       */
/*输入参数：priv：优先级；skb 报文；state：netfilter钩子状态。                     */
/*输出参数: 无*/
/*返回值：固定返回NF_ACCEPT表示放行报文。                                      */
/****************************************************************/
unsigned int pdelivery_hook_func(void *priv,
			       struct sk_buff *skb,
			       const struct nf_hook_state *state)
{
    void *payload;
    struct sk_buff *out_skb;
    void *out_payload;
    struct nlmsghdr *out_nlh;
    int payload_len; // with padding, but ok for echo 
	struct iphdr *iph;
	int ret = -1;
			
	iph = ip_hdr(skb);
	printk(KERN_INFO "pdelivery_hook_func:pktlen=%d,mac_header = %d IP:",skb->len,skb->mac_len);
	printk_ipaddress(iph->saddr);
	printk(KERN_INFO "-->");
	printk_ipaddress(iph->daddr);
	
	payload = skb_mac_header(skb);
    payload_len = skb->len + skb->mac_len;/**/

	
    out_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); //分配足以存放默认大小的sk_buff
    if (!out_skb) goto failure;
	
    out_nlh = nlmsg_put(out_skb, 0, 0, NLMSG_RECV_RAW_PKT, payload_len, 0); //填充协议头数据
    if (!out_nlh) goto failure;
	
    out_payload = nlmsg_data(out_nlh);
    memcpy(out_payload, payload,payload_len);/**/
	
#if 1
	printk(KERN_INFO "%02x %02x %02x %02x %02x %02x %02x %02x\r\n",
		*((char*)out_payload),*((char*)out_payload+1),
		*((char*)out_payload+2),*((char*)out_payload+3),
		*((char*)out_payload+4),*((char*)out_payload+5),
		*((char*)out_payload+6),*((char*)out_payload+7));
#endif

	ret = nf_nlmsg_multicast(&g_nlcfg, out_skb);

#if 0
	ret = nlmsg_multicast(g_nlcfg.sk,out_skb,0,PDNLGRP_ALLRAW,0);
	if (ret < 0) 
	{
		printk(KERN_INFO "Error while sending pkt to user, err id: %d\n", ret);
	}
	g_nlcfg.pkt_delev_num ++;

#endif
	//g_nlcfg.pkt_delev_num ++;
	printk(KERN_INFO "pdelivery_hook_func() end.\n");
	return NF_ACCEPT;/*must return a value*/
	
failure:
    printk(KERN_INFO " failed in pdelivery_hook_func!\n");

	return NF_ACCEPT;/*must return a value*/
}




module_init(pdelivery_init);
module_exit(pdelivery_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("a simple example for upm(user policy manage) netlink protocal family");
MODULE_AUTHOR("RSLjdkt");