#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 "usercfg_kinit.h"

#include "../../../../../Common/commuapinl.h"

#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 netlinkk_cfg g_upmnlcfg;
struct commnl_msgtype_process cfgnl_msg_handlers[COMMCFG_NLMSG_MAX_TYPE];


/*全局变量，存放免认证规则信息,目前只考虑放一条免认证规则，以结构体形式存放，后期考虑链表存放 */
freeauth_configure_t * kfreeauth;


/*全局变量,存放配置的用户老化时间 */
int *kaging_time = NULL;


int nl_cfg_data_ready(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack)
{
	int ret = 0;
     
	printk(KERN_DEBUG "nl_cfg_data_ready() nlmsg_type = %d begin.\n",nlh->nlmsg_type);
	g_upmnlcfg.dfs.rev_total++;
	
	if(NULL != cfgnl_msg_handlers[nlh->nlmsg_type].doit)
	{
		cfgnl_msg_handlers[nlh->nlmsg_type].dfs.rev_total++;
		ret = cfgnl_msg_handlers[nlh->nlmsg_type].doit(skb, nlh,extack);
		if(ret >= 0)
		{
			g_upmnlcfg.dfs.rev_cb_sucess++;
			cfgnl_msg_handlers[nlh->nlmsg_type].dfs.rev_cb_sucess++;
		}
		else
		{
			g_upmnlcfg.dfs.rev_cb_fail++;
			cfgnl_msg_handlers[nlh->nlmsg_type].dfs.rev_cb_fail++;
		}
		
	}
	else
	{
		cfgnl_msg_handlers[nlh->nlmsg_type].dfs.rev_drop_total++;
		cfgnl_msg_handlers[nlh->nlmsg_type].dfs.rev_drop_nodoit++;
		g_upmnlcfg.dfs.rev_drop_total++;		
		g_upmnlcfg.dfs.rev_drop_nodoit++;
		
		printk(KERN_WARNING "no doit fun register with nlmsg_type = %d .\n",nlh->nlmsg_type);
	}
			
	printk(KERN_DEBUG "nl_cfg_data_ready() nlmsg_type = %d end.\n",nlh->nlmsg_type);
	
	return ret;
}


static void libcfgnl_rcv(struct sk_buff *skb)
{
	printk(KERN_DEBUG "libcfgnl_rcv:\n");
	netlink_rcv_skb(skb, &nl_cfg_data_ready);
	
}


/*单播，内核态发送给用户态 */
int cfgnl_unicast(struct sk_buff *skb, u32 portid)
{
	int ret = -1;	
	struct nlmsghdr *nlh = NULL;
	int msgtype = 0;
  
	/**
 	* nlmsg_unicast - unicast a netlink message
 	* @sk: netlink socket to spread message to
 	* @skb: netlink message as socket buffer
 	* @portid: netlink portid of the destination socket
 	*/
	ret = commnl_unicast(g_upmnlcfg.sk, skb, portid);

	if(ret < 0)
	{
		g_upmnlcfg.dfs.send_fail++;
		g_upmnlcfg.dfs.send_fail_reason = ret;
	}
	else
	{
		g_upmnlcfg.dfs.send_succ++;	
	}


	nlh = (struct nlmsghdr *)skb->head;
	msgtype = nlh->nlmsg_type;
	if(msgtype > COMMCFG_NLMSG_MAX_TYPE) 
	{
		printk(KERN_ERR "cfg_unicast:msg type invalid.\r\n");
	}
	else
	{
		printk(KERN_DEBUG "cfg_unicast:msg type %d.\r\n",msgtype);
		if(ret < 0)
		{
			cfgnl_msg_handlers[msgtype].dfs.send_fail++;
		}
		else
		{
			cfgnl_msg_handlers[msgtype].dfs.send_succ++; 
		}
	}

	return(ret);
}


/*免认证规则配置的功能函数，解析出配置信息，存全局变量*/
int usercfg_freeauth(struct sk_buff *skb, struct nlmsghdr *nlh,struct netlink_ext_ack *extack)
{
	char *pload;
	struct nlattr *rta;
	char *load;

	/**
    * nlmsg_data - head of message payload
    * @nlh: netlink message header
    */
	pload = nlmsg_data(nlh);
	rta = (struct nlattr *)pload;
	load = RTA_DATA(rta);

	kfreeauth = (freeauth_configure_t *)load;

	printk("name:%s  sip:%d\n", kfreeauth->name, kfreeauth->sip);
    printk("dip:%d  dport:%d\n", kfreeauth->dip, kfreeauth->dport);

	return 0;
}

/*用户老化时间配置的功能函数，解析出配置信息，存全局变量 */
int usercfg_agingtime(struct sk_buff *skb, struct nlmsghdr *nlh,struct netlink_ext_ack *extack)
{
    char *pload;
	struct nlattr *rta;
	char *load;

	pload = nlmsg_data(nlh);
	rta = (struct nlattr *)pload;
	load = RTA_DATA(rta);

    kaging_time = (int *)load;

	printk("agingtime: %d\n", *kaging_time);

	return 0;
}


int cfg_msgtype_register( int msgtype,commnl_doit_func doit, 
			commnl_dumpit_func dumpit,commnl_calcit_func calcit)
{	
	if(msgtype >= COMMCFG_NLMSG_MAX_TYPE )
	{
		printk(KERN_ERR"netlink.ko-msgtype register invalid msgtype %d,protocl comcfg.\r\n",msgtype);
		return -1;
	}

	/*函数功能：注册内核态配置接收消息处理函数。 */
    /*输入参数:              */
    /*msgtype:注册的消息类型。*/
    /*doit:对应的消息接收处理函数；*/
    /*dumpit,calcit:框架预留接口，暂未使用。填NULL.*/
    /*输出参数: WU */
    /*返回值：0注册成功；< 0,失败*/	
	commnl_register(cfgnl_msg_handlers, msgtype, doit, dumpit, calcit);
	
	printk(KERN_INFO"netlink.ko-msgtype register sucess msgtype %d,protocl comcfg.\r\n",msgtype);
	 
	return 0;
}


/*commcfgmsgtype:FREEAUTH_CFG = 0x13, 用户态发送给内核态的免认证规则消息*/
/*AGINGTIME_CFG = 0x14, 用户态发送给内核态的用户老化时间消息 */
int __init usercfgrcv_init(void)
{
    int ret = -1;

    printk(KERN_INFO "usercfgrcv.ko-initialed\n");

    g_upmnlcfg.msg_processer = &(cfgnl_msg_handlers[0]);
    g_upmnlcfg.msg_processer_num = COMMCFG_NLMSG_MAX_TYPE;

    /*init for usercfg module */
    g_upmnlcfg.groups = 0;
    g_upmnlcfg.subscriptions = NETLINK_COMMCFG; /*创建配置处理通道 */
    g_upmnlcfg.cfg.input = libcfgnl_rcv;

    
    /*函数功能：在内核态创建报文上送通道，上送的 */
    /*报文内容从链路层头开始。一个netlink协议号只能创建一个通道。  */
    /*输入参数：g_nlcfg                                        */
    /*输出参数: wu                                             */
    /*返回值：0通道创建成果；< 0,失败                            */
    ret = libnetlinkk_init_byproto(&g_upmnlcfg);
    if(ret < 0)
    {
        return ret;
    }

    /*do msg process register */
    ret = cfg_msgtype_register(FREEAUTH_CFG, usercfg_freeauth, NULL, NULL);
    ret = cfg_msgtype_register(AGINGTIME_CFG, usercfg_agingtime, NULL, NULL);

    return ret;
}


void __exit usercfgrcv_exit(void)
{
    printk(KERN_CRIT "nl_upm existing...\n");
    libnetlinkk_exit(&g_upmnlcfg);
}


EXPORT_SYMBOL_GPL(cfgnl_unicast);
EXPORT_SYMBOL_GPL(cfg_msgtype_register);

module_init(usercfgrcv_init);
module_exit(usercfgrcv_exit);