#include "board.h"
#include "api.h"
#include "sockets.h"

typedef struct icmp_hdr

{

    unsigned char   icmp_type; // 消息类型

    unsigned char   icmp_code; // 代码

    unsigned short  icmp_checksum; // 校验和

    // 下面是回显头

    unsigned short  icmp_id; // 用来惟一标识此请求的ID号

    unsigned short  icmp_sequence; // 序列号

    unsigned long   icmp_timestamp; // 时间戳

} ICMP_HDR, *PICMP_HDR;



typedef struct _IPHeader// 20字节的IP头

{

    uint8_t     iphVerLen; // 版本号和头长度（各占4位）

    uint8_t     ipTOS; // 服务类型

    uint16_t    ipLength; // 封包总长度，即整个IP报的长度

    uint16_t    ipID;  // 封包标识，惟一标识发送的每一个数据报

    uint16_t    ipFlags; // 标志

    uint8_t     ipTTL; // 生存时间，就是TTL

    uint8_t     ipProtocol; // 协议，可能是TCP、UDP、ICMP等

    uint16_t    ipChecksum; // 校验和

    uint32_t    ipSource; // 源IP地址

    uint32_t    ipDestination; // 目标IP地址

} IPHeader, *PIPHeader;

typedef int SOCKET;

void ping_test(void)
{
	const char * szDestIp = "192.168.137.1";
	long nRet = 0;
	ICMP_HDR* pIcmp = NULL;
	char buff[sizeof(ICMP_HDR) + 32];
	socklen_t nLen = 0;
	ICMP_HDR* pRecvIcmp = NULL;

	/*****************第一步：申请SOCKET************************************/

	uint32_t ip = inet_addr(szDestIp);
	SOCKET sRaw = lwip_socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);

	if(sRaw == -1) {
		printf("Cannot create socket! Error %d\r\n", errno);
		goto exit;
	}

	// 设置接收超时

	struct timeval tv_out;
	tv_out.tv_sec = 10;
	tv_out.tv_usec = 0;
	nRet = setsockopt(sRaw, SOL_SOCKET,SO_RCVTIMEO, &tv_out, sizeof(tv_out));

	if(-1 == nRet) {
		printf("Cannot set timeout! %d \r\n",errno);
	}

	/*****************第二步：组ICMP包************************************/

	// 创建ICMP封包
	pIcmp = (ICMP_HDR*)buff;

	// 填写ICMP封包数据
	pIcmp->icmp_type = 8; // 请求一个ICMP回显
	pIcmp->icmp_code = 0;
	pIcmp->icmp_id = (uint16_t)0x1234;
	pIcmp->icmp_checksum = 0;
	pIcmp->icmp_sequence = 0;
	pIcmp->icmp_timestamp = 0xffff;

	// 填充数据部分，可以为任意
	memset(&buff[sizeof(ICMP_HDR)], 'E', 32);


	/*****************第三步：发送ICMP包************************************/

	//设置目的地址

	struct sockaddr_in dest;
	dest.sin_family = AF_INET;
	dest.sin_port = htons(0);
	dest.sin_addr.s_addr = ip;
	//pIcmp->icmp_checksum = checksum((uint16_t*)buff, sizeof(ICMP_HDR) + 32);   //如果ping过去没回应需要屏蔽这条
	//printf("icmp_checksum = %x\r\n",pIcmp->icmp_checksum);
	nRet = (long)sendto(sRaw, buff, sizeof(ICMP_HDR) + 32, 0, (struct sockaddr *)&dest, sizeof(dest));
	if(nRet == -1) {
		printf(" sendto() failed: %d \r\n", errno);
		goto exit;
	}
	printf("sendto = %ld\r\n",nRet);

	/*****************第四步：接收ICMP包************************************/
	char recvBuf[1024];
	struct sockaddr_in from;
	nLen = sizeof(from);
	nRet = (long)recvfrom(sRaw, recvBuf, 1024, 0, (struct sockaddr *)&from, &nLen);
	if(nRet == -1) {
		printf(" recvfrom() failed: %d\r\n", errno);
		goto exit;
	}
	printf("recvfrom = %ld\r\n",nRet);

	/*****************第五步：解析ICMP包************************************/
	if(nRet < sizeof(IPHeader) + sizeof(ICMP_HDR)) {
		printf(" Too few bytes from %s \r\n", inet_ntoa(from.sin_addr));
	}

#if 0 // IP头解析

	IPHeader * header = (IPHeader*)recvBuf;
	struct in_addr a;
	a.s_addr = header->ipSource;
	printf("source ip %s\n", inet_ntoa(a));
	a.s_addr = header->ipDestination;
	printf("dest ip %s\n", inet_ntoa(a));
#endif

	pRecvIcmp = (ICMP_HDR*)(recvBuf + 20); // 接收到的数据中包含IP头，IP头大小为20个字节，所以加20得到ICMP头

	if(pRecvIcmp->icmp_type != 0) { // 回显
		printf("nonecho type %d recvd \r\n", pRecvIcmp->icmp_type);
		goto exit;
	}

	if(pRecvIcmp->icmp_id != 0x1234) {
		printf(" someone else's packet! \r\n");
		goto exit;
	}

	printf(" %d bytes from %s:", (int)nRet, inet_ntoa(from.sin_addr));
	printf(" icmp_seq = %d. ", pRecvIcmp->icmp_sequence);
	printf(" \r\n");



exit:
	if (sRaw != -1)
		lwip_close(sRaw);

	return ;
}