关于windows下的tcp/ip下的socket实现ping
1.在socket下 接收的数据包和发送的数据包只是数据部分,还是既有协议头部分,还是不同的情况下接受的数据是不同类型的
2.socket下icmp是程序员自己控制的吗?如果是, icmp是网络层的, 为什么可以用udp(传输层)数据包控制底层(网络层)的协议格式呢,还是icmp协议下的数据就是控制信息 ?
3.请大神给说下socket下的什么协议是可以由程序员自己控制; 什么是已经实现了的, 直接供程序员使用的;
坐等
// Description:
// This sample illustrates how an ICMP ping app can be written
// using the SOCK_RAW socket type and IPPROTO_ICMP protocol.
// By creating a raw socket, the underlying layer does not change
// the protocol header so that when we submit the ICMP header
// nothing is changed so that the receiving end will see an
// ICMP packet. Additionally, we use the record route IP option
// to get a round trip path to the endpoint. Note that the size
// of the IP option header that records the route is limited to
// nine IP addresses.
//
// Compile:
// cl -o Ping Ping.c ws2_32.lib /Zp1
//
// Command Line Options/Parameters:
// Ping [host] [packet-size]
//
// host String name of host to ping
// packet-size Integer size of packet to send
// (smaller than 1024 bytes)
//
//#pragma pack(1)
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>
#define WIN32_LEAN_AND_MEAN
#pragma comment(lib,"ws2_32.lib")
#define IP_RECORD_ROUTE 0x7
// IP header structure
typedef struct _iphdr
{
//Suppose the BYTE_ORDER is LITTLE_ENDIAN
unsigned int h_len:4; // Length of the header
unsigned int version:4; // Version of IP
unsigned char tos; // Type of service
unsigned short total_len; // Total length of the packet
unsigned short id; // Unique identification
unsigned short frag_offset; // Fragment offset
unsigned char ttl; // Time to live
unsigned char protocol; // Protocol (TCP, UDP etc)
unsigned short checksum; // IP checksum
unsigned int sourceIP; // Source IP
unsigned int destIP; // Destination IP
} IpHeader;
#define ICMP_ECHO 8
#define ICMP_ECHOREPLY 0
#define ICMP_MIN 8 // Minimum 8-byte ICMP packet (header)
// ICMP header structure
// This is not the standard header, but we reserve space for time
typedef struct _icmphdr
{
BYTE i_type;
BYTE i_code; // Type sub code
USHORT i_cksum;
USHORT i_id;
USHORT i_seq;
ULONG timestamp;
} IcmpHeader;
// IP option header - use with socket option IP_OPTIONS
typedef struct _ipoptionhdr
{
unsigned char code; // Option type
unsigned char len; // Length of option hdr
unsigned char ptr; // Offset into options
unsigned long addr[9]; // List of IP addrs
} IpOptionHeader;
#define DEF_PACKET_SIZE 32 // Default packet size
#define MAX_PACKET 1024 // Max ICMP packet size
#define MAX_IP_HDR_SIZE 60 // Max IP header size w/options
BOOL bRecordRoute;
int datasize;
char *lpdest;
// Function: usage
// Description:
// Print usage information
void usage(char *progname)
{
printf("usage: ping -r <host> [data size] ");
printf(" -r record route ");
printf(" host remote machine to ping ");
printf(" datasize can be up to 1KB ");
ExitProcess(-1);
}
// Function: FillICMPData
// Description:
// Helper function to fill in various fields for our ICMP request
void FillICMPData(char *icmp_data, int datasize)
{
IcmpHeader *icmp_hdr = NULL;
char *datapart = NULL;
icmp_hdr = (IcmpHeader*)icmp_data;
icmp_hdr->i_type = ICMP_ECHO; // Request an ICMP echo, type is 8
icmp_hdr->i_code = 0; // code is 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));
}
// Function: checksum
// Description:
// This function calculates the 16-bit one's complement sum
// of the supplied buffer (ICMP) header
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);
}
// Function: DecodeIPOptions
// Description:
// If the IP option header is present, find the IP options
// within the IP header and print the record route option values
void DecodeIPOptions(char *buf, int bytes)
{
IpOptionHeader *ipopt = NULL;
IN_ADDR inaddr;
int i;
HOSTENT *host = NULL;
ipopt = (IpOptionHeader *)(buf + 20);
printf("Record Route: ");
for(i = 0; i < (ipopt->ptr / 4) - 1; i++)
{
inaddr.S_un.S_addr = ipopt->addr[i];
if (i != 0) printf(" ");
host = gethostbyaddr((char *)&inaddr.S_un.S_addr, sizeof(inaddr.S_un.S_addr), AF_INET);
if (host)
printf("(%-15s) %s ", inet_ntoa(inaddr), host->h_name);
else
printf("(%-15s) ", inet_ntoa(inaddr));
}
printf("\n");
return;
}
// Function: DecodeICMPHeader
// Description:
// The response is an IP packet. We must decode the IP header to
// locate the ICMP data.
void DecodeICMPHeader(char *buf, int bytes, struct sockaddr_in *from)
{
IpHeader *iphdr = NULL;
IcmpHeader *icmphdr = NULL;
unsigned short iphdrlen;
DWORD tick;
static int icmpcount = 0;
iphdr = (IpHeader *)buf;
// Number of 32-bit words * 4 = bytes
iphdrlen = iphdr->h_len * 4;
tick = GetTickCount();
if((iphdrlen == MAX_IP_HDR_SIZE) && (!icmpcount))
DecodeIPOptions(buf, 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) // echo type must be 0
{
printf("non-echo type %d recvd \n", icmphdr->i_type);
return;
}
// Make sure this is an ICMP reply to something we sent!
// In FillICMPData function we assign the i_id is GetCurrentProcessId()
if(icmphdr->i_id != (USHORT)GetCurrentProcessId())
{
printf("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", tick - icmphdr->timestamp);
printf("\n");
icmpcount++;
return;
}
[解决办法]
google/baidu raw socket