#ifdef __cplusplus
extern "C" {
#endif

#include <getopt.h>
#include <pcap/pcap.h>
#include "MESA_jump_layer.h"

static pcap_t *g_pcap_handle;
static char *g_input_pcap_name;
static char *g_input_bpf_string;
static struct bpf_program g_bpf_filter;

static int g_raw_input_layer_type = (int )ADDR_TYPE_MAC;
static int g_expect_layer_type = (int )ADDR_TYPE_IPV4;

static void usage(const char *prog)
{
	printf("Usage:\n");
	printf("\t-r set input pcap file.\n");
	printf("\t-f set pcap BPF fileter.\n");
	exit(0);
}

static int pcap_set_bpf(pcap_t *handle, const char *filter_str)
{
	struct bpf_program bpf_filter;

	if((NULL == handle) || (NULL == filter_str) || ('\0' == *filter_str)){
		return 0;
	}
	
	if(pcap_compile(handle, &bpf_filter, (char *)filter_str, 1, 0) < 0)
	{
		printf("Compile pcap filter '%s' error:%s\n", filter_str, pcap_geterr(handle));
		return -1;
	}

	if(pcap_setfilter(handle, &bpf_filter) < 0){
		printf("Set pcap filter '%s' error:%s\n", filter_str, pcap_geterr(handle));
		return -1;
	}

	return 0;
}

static int pcap_init(void)
{
	char err_string[PCAP_ERRBUF_SIZE];
	
	g_pcap_handle = pcap_open_offline(g_input_pcap_name, err_string);
	if(NULL == g_pcap_handle){
		printf("open file:%s error, %s\n", g_input_pcap_name, err_string);
		return -1;
	}
	
	if(pcap_compile_nopcap(65535, DLT_RAW, &g_bpf_filter, g_input_bpf_string, 1, 0) < 0){				 
		printf("Compile pcap filter '%s' error\n", g_input_bpf_string);				  
		return -1; 
	}

	return 0;
}

static void _jump_from_udp(const void *uhdr)
{
	const void *next_hdr;
	
	next_hdr = MESA_jump_layer(uhdr, ADDR_TYPE_UDP, ADDR_TYPE_GPRS_TUNNEL);
	if(next_hdr){
		printf("bingo! jump to gtp from udp succ!\n");
	}	

	next_hdr = MESA_jump_layer(uhdr, ADDR_TYPE_UDP, ADDR_TYPE_L2TP);
	if(next_hdr){
		printf("bingo! jump to l2tp from udp succ!\n");
	}		
}


static void _jump_from_ipv4(const void *ip4_hdr)
{
	const void *next_hdr;
	
	next_hdr = MESA_jump_layer(ip4_hdr, ADDR_TYPE_IPV4, ADDR_TYPE_TCP);
	if(next_hdr){
		printf("bingo! jump to tcp from ipv4 succ!\n");
	}	

	next_hdr = MESA_jump_layer(ip4_hdr, ADDR_TYPE_IPV4, ADDR_TYPE_UDP);
	if(next_hdr){
		printf("bingo! jump to udp from ipv4 succ!\n");
		_jump_from_udp(next_hdr);
	}		
}

static void _jump_from_ipv6(const void *ip4_hdr)
{
	
}



static void _jump_from_ethernet(const void *ehdr)
{
	const void *next_hdr;
	
	next_hdr = MESA_jump_layer(ehdr, ADDR_TYPE_MAC, ADDR_TYPE_IPV4);
	if(next_hdr){
		printf("bingo! jump to ipv4 from ethernet succ!\n");
		_jump_from_ipv4(next_hdr);
	}

	next_hdr = MESA_jump_layer(ehdr, ADDR_TYPE_MAC, ADDR_TYPE_IPV6);
	if(next_hdr){
		printf("bingo! jump to ipv6 from ethernet succ!\n");
		_jump_from_ipv6(next_hdr);
	}

}


static void _jump_greedy(const struct pcap_pkthdr *hdr, const u_char *data)
{
	const void *ip4_hdr, *ip6_h;

	char print_buf[128];
	int offset_to_eth;
	static int pkt_index = 0;
	
	ip4_hdr = MESA_jump_layer_greedy(data, ADDR_TYPE_MAC, ADDR_TYPE_IPV4);
	ip6_h = MESA_jump_layer_greedy(data, ADDR_TYPE_MAC, ADDR_TYPE_IPV6);
	

		printf("-----------------------------packet index:%d------------------------------------------\n", pkt_index++);
		if(ip4_hdr){
			offset_to_eth = (u_char *)ip4_hdr-data;
			if(g_input_bpf_string 
			 && (0 == bpf_filter(g_bpf_filter.bf_insns, (const unsigned char *)ip4_hdr, hdr->caplen-offset_to_eth, hdr->caplen-offset_to_eth))){
				goto done;
			}
			printf("Innermost layer ipv4 offset:%d, addr: %s\n", offset_to_eth, MESA_jump_layer_ipv4_ntop((struct ip *)ip4_hdr, print_buf, sizeof(print_buf)));
		}
	
		if(ip6_h){
			offset_to_eth = (u_char *)ip6_h-data;
			if(g_input_bpf_string 
			 && (0 == bpf_filter(g_bpf_filter.bf_insns, (const unsigned char *)ip6_h, hdr->caplen-offset_to_eth, hdr->caplen-offset_to_eth))){
				goto done;
			}
	
			printf("Innermost layer ipv6 offset:%d, addr: %s\n", offset_to_eth, MESA_jump_layer_ipv6_ntop((struct ip6_hdr *)ip6_h, print_buf, sizeof(print_buf)));
		}
	
	done:
	
		printf("--------------------------------------------------------------------------------------\n\n");

}

static void _pcap_pkt_handle(u_char *user, const struct pcap_pkthdr *hdr, const u_char *data)
{

	_jump_from_ethernet(data);
	
	_jump_greedy(hdr, data);

}

static void pcap_run(void)
{
	
	pcap_loop(g_pcap_handle, -1, _pcap_pkt_handle, NULL);
}

int main(int argc, char *argv[])
{
	int ret, c, opt_index;
	
	while(1){
	c = getopt_long(argc, argv, "hr:f:", NULL, &opt_index);
		if(c == -1){
			ret = 0;
			break;	
		}

		switch(c){
			case 'h':
				usage(argv[0]);
			break;
			
			case 'r':
				g_input_pcap_name = strdup(optarg);
			break;
			
			case 'f':
				g_input_bpf_string = strdup(optarg);
			break;
			
			default:
				return -1;
		}	
	}	
	
	if(NULL == g_input_pcap_name){
		printf("error! must set pcap file name use -r\n");
		return -1;
	}

	if(NULL == g_input_bpf_string){
		printf("you can set BPF filter use -f\n");
	}
	
	if(pcap_init() < 0){
		return -1;
	}
	
	pcap_run();
	
	return 0;
}


#ifdef __cplusplus
}
#endif