#include "flowood.h"
#include "flowood_fun.h"
#include "flwd_net.h"
#include <pcap/pcap.h>
#include "MESA_list_queue.h"
#include "MESA_handle_logger.h"
#include "MESA_prof_load.h"
#include <sys/types.h> 
#include <sys/socket.h>
#include <string.h>
#include <arpa/inet.h>
#include <assert.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <net/if_arp.h>
#include <net/if.h>

#ifdef __cplusplus    
/* 需要动态dlopen获取符号名, 使用C规范 */
extern "C" {
#endif

       
typedef struct {
	pthread_t pid;
	unsigned char thread_seq;
	int sd_raw_eth; /* 底层发包socket句柄 */
	struct sockaddr sock_addr;
	MESA_lqueue_head pkt_queue;
}pcap_work_thread_t;

typedef struct{
	char *__data_buf;       /* mbuff缓冲区头指针 */
	char *data_actual_ptr; /* 当前缓存实际存储的数据指针 */
	int __data_buf_max_len; 	/* mbuff最大缓存长度, 即FLWD_LINK_MTU */
	int data_actual_len;	/* 当前缓存中实际存储的数据长度 */
}pcap_mbuff_t;

/* pcap模式内部句柄结构 */
typedef struct{
	int tot_thread_count;
	pcap_t *pcap_dev_handle;
	pcap_work_thread_t pcap_io_thread_para[FLWD_MAX_THREAD_NUM];
	pcap_mbuff_t pcap_send_buf[FLWD_MAX_THREAD_NUM]; /* 发包缓存, 初始化时申请, 以后发包不用每次动态malloc/free */
}flwd_device_handle_pcap_t;

typedef struct{
	char *pkt_data;
	int pkt_len;
}pcap_queue_item_t;

/* 2012-04-10 LiJia add, 获取网卡MAC地址
参数:
	device: 网卡名称
	mac: 存储MAC地址的数组,结果为网络序,
		 如网卡MAC地址为11:22:33:44:55:66,则mac[0]为0x11,mac[5]为0x66.
返回值:
	0: 正常
	-1:错误
*/
static int MESA_get_dev_mac(const char *device, unsigned char mac[6])
{
    struct ifreq ifr;
    int fd;

    fd = socket(AF_INET, SOCK_DGRAM, 0);
    if(fd < 0)
    {
        return -1;
    }

    memset(ifr.ifr_ifrn.ifrn_name, 0, sizeof(ifr.ifr_ifrn.ifrn_name));
    strncpy(ifr.ifr_ifrn.ifrn_name, device, sizeof(ifr.ifr_ifrn.ifrn_name));
    if(ioctl(fd, SIOCGIFHWADDR, &ifr) == -1) 
    {
        printf("Cann't get hwaddr of %s:%s\n", device, strerror(errno));
        goto err_exit;
    }

    if(ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER)
    {
		printf("'%s' is not ethernet interface!\n", device);
		goto err_exit;
    }

    memcpy(mac, ifr.ifr_ifru.ifru_addr.sa_data, 6);

    close(fd);

    return 0;

err_exit:
    close(fd);
    return -1;
}

static inline int flwd_pcap_dispatch_thread(flwd_device_handle_pcap_t *pcap_io_handle, const u_char *data)
{
	int to_work_thread_seq;
	const flwd_eth_hdr_t  *flwd_eth_hdr = (flwd_eth_hdr_t *)data;
	const flwd_ipv4_hdr_t *flwd_ip_hdr;

	if(ETH_P_IP == ntohs(flwd_eth_hdr->h_proto)){
		flwd_ip_hdr = (flwd_ipv4_hdr_t *)(data + sizeof(flwd_eth_hdr_t));
		to_work_thread_seq =  (flwd_ip_hdr->ip_src.s_addr ^ flwd_ip_hdr->ip_dst.s_addr) % pcap_io_handle->tot_thread_count;
	}else{
		to_work_thread_seq = 0;/* 其他协议默认用0核心 */
	}

	return to_work_thread_seq;
}



static pcap_mbuff_t *flwd_pcap_create_new_mbuff(u_char *data, int datalen)
{
	pcap_mbuff_t *pcap_mbuff;

	pcap_mbuff = (pcap_mbuff_t *)calloc(1, sizeof(pcap_mbuff_t));

	pcap_mbuff->__data_buf = (char *)malloc(datalen + FLWD_VXLAN_OUTER_PACKET_LEN); /* 预留vxlan头部 */
	pcap_mbuff->__data_buf_max_len = datalen + FLWD_VXLAN_OUTER_PACKET_LEN;
	
	
	pcap_mbuff->data_actual_ptr = pcap_mbuff->__data_buf + FLWD_VXLAN_OUTER_PACKET_LEN;
	pcap_mbuff->data_actual_len = datalen;

	memcpy(pcap_mbuff->data_actual_ptr, data, datalen);

	return pcap_mbuff;
}


static void flwd_pcap_pkt_handle(u_char *user, const struct pcap_pkthdr *hdr, const u_char *data)
{
	int to_work_thread_seq;
	pcap_mbuff_t *pcap_mbuff;
	flwd_device_handle_pcap_t *pcap_io_handle = (flwd_device_handle_pcap_t *)user;

	to_work_thread_seq = flwd_pcap_dispatch_thread(pcap_io_handle, data);

	pcap_mbuff = flwd_pcap_create_new_mbuff((u_char *)data, hdr->caplen);

	/* NOTE: 此处可以用阻塞接口, 因为pcap_loop在独立的线程上下文空间, 不影响其他流程 */
	int ret = MESA_lqueue_join_tail(pcap_io_handle->pcap_io_thread_para[to_work_thread_seq].pkt_queue, &pcap_mbuff, sizeof(void *));
	if(ret < 0){
		free(pcap_mbuff->__data_buf);
		free(pcap_mbuff);
		printf("pcap io thread MESA_lqueue_join_tail() error, ret=%d\n", ret);
	}
	
}

static int pcap_low_level_io_init(flwd_device_handle_t *global_dev_handle)
{
	int i;
	char pcap_errbuf[PCAP_ERRBUF_SIZE];
	char str_tmp[128];
	struct bpf_program bpf_filter;
	
	flwd_device_handle_pcap_t *pcap_io_handle = (flwd_device_handle_pcap_t *)calloc(1, sizeof(flwd_device_handle_pcap_t));

	pcap_io_handle->pcap_dev_handle = pcap_open_live(global_dev_handle->io_para.device_name, 4096, 1, 1, pcap_errbuf);
	if(NULL == pcap_io_handle->pcap_dev_handle){
		flwd_log(RLOG_LV_FATAL, "pcap_open_live() error, %s\n", pcap_errbuf);
		return -1;
	}
	/* TODO, set filter */
	if(global_dev_handle->io_para.pkt_filter != NULL){
		if(pcap_compile(pcap_io_handle->pcap_dev_handle, &bpf_filter, (char *)global_dev_handle->io_para.pkt_filter, 1, 0) < 0){
			flwd_log(RLOG_LV_FATAL, "pcap_compile() error, invalid pkt_filter: %s\n", global_dev_handle->io_para.pkt_filter);
			return -1;
		}

		pcap_setfilter(pcap_io_handle->pcap_dev_handle, &bpf_filter);
	}
	
	pcap_setdirection(pcap_io_handle->pcap_dev_handle, PCAP_D_IN); /* 只捕收包 */

	for(i = 0; i < global_dev_handle->tot_thread_count; i++){
		pcap_io_handle->pcap_io_thread_para[i].thread_seq = i;
		pcap_io_handle->pcap_send_buf[i].__data_buf = (char *)malloc(FLWD_LINK_MTU);
		pcap_io_handle->pcap_send_buf[i].__data_buf_max_len = FLWD_LINK_MTU;
		pcap_io_handle->pcap_io_thread_para[i].sd_raw_eth = socket(PF_INET, SOCK_PACKET, htons(ETH_P_ALL));

		snprintf(pcap_io_handle->pcap_io_thread_para[i].sock_addr.sa_data, 
				sizeof(pcap_io_handle->pcap_io_thread_para[i].sock_addr.sa_data), 
				"%s", global_dev_handle->io_para.device_name);
	
		pcap_io_handle->pcap_io_thread_para[i].pkt_queue = MESA_lqueue_create(1, 50000);
	}

	MESA_load_profile_string_def(FLWD_CONFIG_FILE, g_packet_io_cfg_para[(int)global_dev_handle->io_para.topo_mode].cfg_file_section, "addr_para", str_tmp, 128, "#");
	if('#' == str_tmp[0]){
		flwd_log(RLOG_LV_FATAL, "get config %s->addr_para error!", g_packet_io_cfg_para[(int)global_dev_handle->io_para.topo_mode].cfg_file_section);
		return -1;
	}
	if(inet_pton(AF_INET, str_tmp, &global_dev_handle->io_para.device_ip_net_order) <= 0){
		flwd_log(RLOG_LV_FATAL, "config %s->addr_para type invalid!", g_packet_io_cfg_para[(int)global_dev_handle->io_para.topo_mode].cfg_file_section);
		return -1;
	}

	MESA_load_profile_string_def(FLWD_CONFIG_FILE, g_packet_io_cfg_para[(int)global_dev_handle->io_para.topo_mode].cfg_file_section, "addr_mask", str_tmp, 128, "#");
	if('#' == str_tmp[0]){
		flwd_log(RLOG_LV_FATAL, "get config %s->addr_mask error!", g_packet_io_cfg_para[(int)global_dev_handle->io_para.topo_mode].cfg_file_section);
		return -1;
	}
	if(inet_pton(AF_INET, str_tmp, &global_dev_handle->io_para.device_ip_mask_net_order) <= 0){
		flwd_log(RLOG_LV_FATAL, "config %s->addr_mask type invalid!", g_packet_io_cfg_para[(int)global_dev_handle->io_para.topo_mode].cfg_file_section);
		return -1;
	}

	MESA_load_profile_string_def(FLWD_CONFIG_FILE, g_packet_io_cfg_para[(int)global_dev_handle->io_para.topo_mode].cfg_file_section, "gateway_ip", str_tmp, 128, "#");
	if('#' == str_tmp[0]){
		flwd_log(RLOG_LV_FATAL, "get config %s->gateway_ip error!", g_packet_io_cfg_para[(int)global_dev_handle->io_para.topo_mode].cfg_file_section);
		return -1;
	}
	if(inet_pton(AF_INET, str_tmp, &global_dev_handle->io_para.gateway_ip_net_order) <= 0){
		flwd_log(RLOG_LV_FATAL, "config %s->gateway_ip type invalid!", g_packet_io_cfg_para[(int)global_dev_handle->io_para.topo_mode].cfg_file_section);
		return -1;
	}
	
	
	MESA_get_dev_mac(global_dev_handle->io_para.device_name, global_dev_handle->io_para.local_mac_addr);
	
	pcap_io_handle->tot_thread_count = global_dev_handle->tot_thread_count;
	global_dev_handle->low_level_io_handle = (void *)pcap_io_handle;
	
	return 0;
}

static int pcap_low_level_send(flwd_device_handle_t *global_dev_handle, int tid, void *mbuff)
{
	int ret;
	pcap_mbuff_t *pcap_mbuff = (pcap_mbuff_t *)mbuff;
	flwd_device_handle_pcap_t *pcap_io_handle = (flwd_device_handle_pcap_t *)global_dev_handle->low_level_io_handle;

	ret = sendto(pcap_io_handle->pcap_io_thread_para[tid].sd_raw_eth, 
			    pcap_mbuff->data_actual_ptr,
			    pcap_mbuff->data_actual_len,
			    MSG_DONTWAIT,
			    (const struct sockaddr *)&pcap_io_handle->pcap_io_thread_para[tid].sock_addr,
			    sizeof(struct sockaddr));
	
	return ret;
}




int low_level_pkt_recv(flwd_device_handle_t *g_dev_handle, int tid, void **mbuff)
{
	int ret, try_times;
	pcap_mbuff_t *pcap_mbuff;
	long recv_len;
	flwd_device_handle_pcap_t *pcap_io_handle = (flwd_device_handle_pcap_t *)g_dev_handle->low_level_io_handle;
	
	recv_len = sizeof(void *);
	
	for(try_times = 0; try_times < 20; try_times++){
		/* NOTE: 因为是trylock, 非常容易失败, 尝试连续多试几次 */
		ret = MESA_lqueue_try_get_head(pcap_io_handle->pcap_io_thread_para[tid].pkt_queue, &pcap_mbuff, &recv_len);
		switch(ret){
			case 0: //OK
				goto done;
			break;
			
			case -5: //empty, no packet
				return -1;
		}
	}

	if(ret < 0){
		return -1;
	}

done:
	*mbuff = (void *)pcap_mbuff;

	return pcap_mbuff->data_actual_len;
}

void low_level_pkt_free(flwd_device_handle_t *g_dev_handle, int tid, void *mbuff)
{
	pcap_mbuff_t *pcap_mbuff = (pcap_mbuff_t *)mbuff;
	
	free(pcap_mbuff->__data_buf);
	free(pcap_mbuff);
	
	return;
}


void *low_level_mbuff_malloc(flwd_device_handle_t *g_dev_handle, int tid, int len)
{
	///flwd_device_handle_pcap_t *pcap_io_handle = (flwd_device_handle_pcap_t *)g_dev_handle->low_level_io_handle;

	pcap_mbuff_t *mbuff = (pcap_mbuff_t *)malloc(sizeof(pcap_mbuff_t));

	mbuff->__data_buf = (char *)malloc(FLWD_LINK_MTU);
	mbuff->data_actual_ptr = mbuff->__data_buf + FLWD_VXLAN_OUTER_PACKET_LEN;
	mbuff->__data_buf_max_len = FLWD_LINK_MTU;
	mbuff->data_actual_len = 0;

	return (void *)mbuff;
}

char *low_level_mbuff_mtod(void *mbuff)
{
	pcap_mbuff_t *pcap_mbuff = (pcap_mbuff_t *)mbuff;
	
	return (char *)pcap_mbuff->data_actual_ptr; 
}

void  low_level_mbuff_free(struct __flwd_device_handle *h, int tid, void *mbuff)
{
	pcap_mbuff_t *pcap_mbuff = (pcap_mbuff_t *)mbuff;
	
	free(pcap_mbuff->__data_buf);
	pcap_mbuff->data_actual_len = 0;
	pcap_mbuff->__data_buf_max_len = 0;
	free(mbuff);
}

void low_level_mbuff_free_after_send(flwd_device_handle_t *g_dev_handle, int tid, void *mbuff)
{
	/* pcap模式发送无自动free, 再次调用真正的free函数 */
	low_level_mbuff_free(g_dev_handle, tid, mbuff);
}


void low_level_mbuff_send_back(flwd_device_handle_t *g_dev_handle, int tid, void *mbuff)
{
	/* pcap模式暂时不用回注gdev数据包, 空函数  */
	return;
}

/*
	在mbuff里追加user_data数据.

	return value:
		数据起始位置;
*/
char * low_level_mbuff_data_append(void *mbuff, const char *user_data, int user_data_len)
{
	pcap_mbuff_t *pcap_mbuff= (pcap_mbuff_t *)mbuff;

	assert(user_data_len <= pcap_mbuff->__data_buf_max_len - pcap_mbuff->data_actual_len);

	memcpy(pcap_mbuff->data_actual_ptr, user_data, user_data_len);
	pcap_mbuff->data_actual_len += user_data_len; 
	
	return (char *)pcap_mbuff->data_actual_ptr;
}

/* 数据指针向前移动N个字节, 数据长度自动增加N, 功能是在现有数据包之前填充其他包头, 如vxlan */
char *low_level_mbuff_data_forward(void *mbuff, int n)
{
	pcap_mbuff_t *pcap_mbuff = (pcap_mbuff_t *)mbuff;
	
	assert(n <= pcap_mbuff->data_actual_ptr - pcap_mbuff->__data_buf);
	
	pcap_mbuff->data_actual_ptr -= n; /* 先前移动 */
	pcap_mbuff->data_actual_len += n; 

	return (char *)pcap_mbuff->data_actual_ptr;
}


/* 数据指针向后移动N个字节, 数据长度自动减少N, 功能是把现有数据包的某些包头跳过, 如剥去vxlan头部 */
char * low_level_mbuff_data_rearward(void *mbuff, int n)
{
	pcap_mbuff_t *pcap_mbuff = (pcap_mbuff_t *)mbuff;
	
	assert(n <= pcap_mbuff->__data_buf_max_len - pcap_mbuff->data_actual_len);

	pcap_mbuff->data_actual_ptr += n;
	pcap_mbuff->data_actual_len -= n; 

	return pcap_mbuff->data_actual_ptr;
}



int low_level_mbuff_get_pkt_len(void *mbuff)
{
	pcap_mbuff_t *pcap_mbuff = (pcap_mbuff_t *)mbuff;

	return pcap_mbuff->data_actual_len;
}

void low_level_mbuff_set_pkt_len(void *mbuff, int pkt_len)
{
	pcap_mbuff_t *pcap_mbuff = (pcap_mbuff_t *)mbuff;

	pcap_mbuff->data_actual_len = pkt_len;
}


int low_level_send(flwd_device_handle_t *global_dev_handle, int tid, void *mbuff)
{
	return pcap_low_level_send(global_dev_handle, tid, mbuff);
}

/* 此函数可以阻塞或死循环, 一直不返回 */
void low_level_io_run(flwd_device_handle_t *global_io_handle)
{	
	///int i;
	///pthread_t pid;
	
	flwd_device_handle_pcap_t *pcap_io_handle = (flwd_device_handle_pcap_t *)global_io_handle->low_level_io_handle;

	while(1){
		pcap_loop(pcap_io_handle->pcap_dev_handle, -1, flwd_pcap_pkt_handle, (u_char	*)pcap_io_handle);
	}
	
	return;
}

int low_level_io_init(flwd_device_handle_t *global_dev_handle)
{
	return pcap_low_level_io_init(global_dev_handle);
}

#ifdef __cplusplus                                                                                                                                                          
}
#endif