如何在linux下用c语言编写一个能够发送icmp报文的小程序

需要建立socket，参数是AF_INET，SOCK_RAW，IPPROTO_ICMP

自己构造ICMP数据包， sendto发送给某地址。

ICMP有多种，你可以发送type为13的时间戳请求。

然后调用recvfrom会收到type为14的timestamp reply的IP包，

IP头一般是20 Bytes，里面包含src IP，des IP还有TTL等。

IP包的数据就是返回ICMP timestamp reply报文，里面有origTimestamp，recvTimestamp，transStamp，可以计算出时间槐闭。

可以参考网页链接网页链接

觉得有哪拆帮助可铅缓裂以注册帐号，给他点个“星”

#pragma pack(4)

#define WIN32_LEAN_AND_MEAN

#include <WINSOCK2.H>

#include <STDIO.H>

#include <STDLIB.H>

#define ICMP_ECHO 8

#define ICMP_ECHOREPLY 0

#define ICMP_MIN 8 // minimum 8 byte icmp packet (just header)

/* The IP header */

typedef struct iphdr {

unsigned int h_len:4// length of the header

unsigned int version:4/液森/ Version of IP

unsigned char tos//没兆 Type of service

unsigned short total_len// total length of the packet

unsigned short ident// unique identifier

unsigned short frag_and_flags// flags

unsigned char ttl

unsigned char proto// protocol (TCP, UDP etc)

unsigned short checksum// IP checksum

unsigned int sourceIP

unsigned int destIP

}IpHeader

//

// ICMP header

//

typedef struct _ihdr {

BYTE i_type

BYTE i_code/* type sub code */

USHORT i_cksum

USHORT i_id

USHORT i_seq

/枯埋租* This is not the std header, but we reserve space for time */

ULONG timestamp

}IcmpHeader

#define STATUS_FAILED 0xFFFF

#define DEF_PACKET_SIZE 32

#define MAX_PACKET 1024

#define xmalloc(s) HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,(s))

#define xfree(p) HeapFree (GetProcessHeap(),0,(p))

void fill_icmp_data(char *, int)

USHORT checksum(USHORT *, int)

void decode_resp(char *,int ,struct sockaddr_in *)

void Usage(char *progname){

fprintf(stderr,"Usage:\n")

fprintf(stderr,"%s <HOST>[data_size]\n",progname)

fprintf(stderr,"datasize can be up to 1Kb\n")

ExitProcess(STATUS_FAILED)

}

int main(int argc, char **argv){

WSADATA wsaData

SOCKET sockRaw

struct sockaddr_in dest,from

struct hostent * hp

int bread,datasize

int fromlen = sizeof(from)

int timeout = 1000

char *dest_ip

char *icmp_data

char *recvbuf

unsigned int addr=0

USHORT seq_no = 0

if (WSAStartup(MAKEWORD(2,1),&wsaData) != 0){

fprintf(stderr,"WSAStartup failed: %d\n",GetLastError())

ExitProcess(STATUS_FAILED)

}

if (argc <2 ) {

Usage(argv[0])

}

sockRaw = WSASocket (AF_INET,

SOCK_RAW,

IPPROTO_ICMP,

NULL, 0,0)

if (sockRaw == INVALID_SOCKET) {

fprintf(stderr,"WSASocket() failed: %d\n",WSAGetLastError())

ExitProcess(STATUS_FAILED)

}

bread = setsockopt(sockRaw,SOL_SOCKET,SO_RCVTIMEO,(char*)&timeout,

sizeof(timeout))

if(bread == SOCKET_ERROR) {

fprintf(stderr,"failed to set recv timeout: %d\n",WSAGetLastError())

ExitProcess(STATUS_FAILED)

}

timeout = 1000

bread = setsockopt(sockRaw,SOL_SOCKET,SO_SNDTIMEO,(char*)&timeout,

sizeof(timeout))

if(bread == SOCKET_ERROR) {

fprintf(stderr,"failed to set send timeout: %d\n",WSAGetLastError())

ExitProcess(STATUS_FAILED)

}

memset(&dest,0,sizeof(dest))

hp = gethostbyname(argv[1])

if (!hp){

addr = inet_addr(argv[1])

}

if ((!hp) &&(addr == INADDR_NONE) ) {

fprintf(stderr,"Unable to resolve %s\n",argv[1])

ExitProcess(STATUS_FAILED)

}

if (hp != NULL)

memcpy(&(dest.sin_addr),hp->h_addr,hp->h_length)

else

dest.sin_addr.s_addr = addr

if (hp)

dest.sin_family = hp->h_addrtype

else

dest.sin_family = AF_INET

dest_ip = inet_ntoa(dest.sin_addr)

if (argc >2) {

datasize = atoi(argv[2])

if (datasize == 0)

datasize = DEF_PACKET_SIZE

}

else

datasize = DEF_PACKET_SIZE

datasize += sizeof(IcmpHeader)

icmp_data = xmalloc(MAX_PACKET)

recvbuf = xmalloc(MAX_PACKET)

if (!icmp_data) {

fprintf(stderr,"HeapAlloc failed %d\n",GetLastError())

ExitProcess(STATUS_FAILED)

}

memset(icmp_data,0,MAX_PACKET)

fill_icmp_data(icmp_data,datasize)

while(1) {

int bwrote

((IcmpHeader*)icmp_data)->i_cksum = 0

((IcmpHeader*)icmp_data)->timestamp = GetTickCount()

((IcmpHeader*)icmp_data)->i_seq = seq_no++

((IcmpHeader*)icmp_data)->i_cksum = checksum((USHORT*)icmp_data,

datasize)

bwrote = sendto(sockRaw,icmp_data,datasize,0,(struct sockaddr*)&dest,

sizeof(dest))

if (bwrote == SOCKET_ERROR){

if (WSAGetLastError() == WSAETIMEDOUT) {

printf("timed out\n")

continue

}

fprintf(stderr,"sendto failed: %d\n",WSAGetLastError())

ExitProcess(STATUS_FAILED)

}

if (bwrote <datasize ) {

fprintf(stdout,"Wrote %d bytes\n",bwrote)

}

bread = recvfrom(sockRaw,recvbuf,MAX_PACKET,0,(struct sockaddr*)&from,

&fromlen)

if (bread == SOCKET_ERROR){

if (WSAGetLastError() == WSAETIMEDOUT) {

printf("timed out\n")

continue

}

fprintf(stderr,"recvfrom failed: %d\n",WSAGetLastError())

ExitProcess(STATUS_FAILED)

}

decode_resp(recvbuf,bread,&from)

Sleep(1000)

}

return 0

}

/*

The response is an IP packet. We must decode the IP header to locate

the ICMP data

*/

void decode_resp(char *buf, int bytes,struct sockaddr_in *from) {

IpHeader *iphdr

IcmpHeader *icmphdr

unsigned short iphdrlen

iphdr = (IpHeader *)buf

iphdrlen = iphdr->h_len * 4 // number of 32-bit words *4 = bytes

if (bytes <iphdrlen + ICMP_MIN) {

printf("Too few bytes from %s\n",inet_ntoa(from->sin_addr))

}

icmphdr = (IcmpHeader*)(buf + iphdrlen)

if (icmphdr->i_type != ICMP_ECHOREPLY) {

fprintf(stderr,"non-echo type %d recvd\n",icmphdr->i_type)

return

}

if (icmphdr->i_id != (USHORT)GetCurrentProcessId()) {

fprintf(stderr,"someone else's packet!\n")

return

}

printf("%d bytes from %s:",bytes, inet_ntoa(from->sin_addr))

printf(" icmp_seq = %d. ",icmphdr->i_seq)

printf(" time: %d ms ",GetTickCount()-icmphdr->timestamp)

printf("\n")

}

USHORT checksum(USHORT *buffer, int size) {

unsigned long cksum=0

while(size >1) {

cksum+=*buffer++

size -=sizeof(USHORT)

}

if(size ) {

cksum += *(UCHAR*)buffer

}

cksum = (cksum >>16) + (cksum &0xffff)

cksum += (cksum >>16)

return (USHORT)(~cksum)

}

/*

Helper function to fill in various stuff in our ICMP request.

*/

void fill_icmp_data(char * icmp_data, int datasize){

IcmpHeader *icmp_hdr

char *datapart

icmp_hdr = (IcmpHeader*)icmp_data

icmp_hdr->i_type = ICMP_ECHO

icmp_hdr->i_code = 0

icmp_hdr->i_id = (USHORT)GetCurrentProcessId()

icmp_hdr->i_cksum = 0

icmp_hdr->i_seq = 0

datapart = icmp_data + sizeof(IcmpHeader)

//

// Place some junk in the buffer.

//

memset(datapart,'E', datasize - sizeof(IcmpHeader))

}

ping 的功能是检测网络的连通性，就是测试你到目的IP是否是连通的，不过如果有任何过滤ICMP包的机制都有可能使你此唯ping不通目的IP 。 用法 ： ping xxx.xxx.xxx.xxx(IP地址) 这是最基本的用法，也可以直接输入网址，后面可以加上其他参数 。在CMD的窗口里只弊辩输入ping，回车后会自动显示ping 的租扒缺用法，很详细。

tracert 的功能是测试你到目的IP的距离（跳数即你到目的IP之间有多少台路由器）。用法：

tracert xxx.xxx.xxx.xxx / 网站网址 。同样的在CMD窗口里也有用法提示。

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