C语言检查本机公网IP并发送邮件

    这是一个用来获取本机公网IP地址，并检查是否是配置里保存的IP地址，如果不是，就向指定的邮箱发送一个邮件，报告这个IP地址的一段小代码。放到开机启动中，电脑不设密码的时候万一丢了，还能有个念想..........功能不强——只简单实现了获取地址，发送邮件的功能，仅供练习之用，而且只能用163的邮箱来发邮件......

    发送邮件的函数是百度上copy的，只是简单的修改了一下






#include <windows.h>
#include <stdio.h>
#include <WinSock.h>
#include <URLMON.H>
#include <FSTREAM>
#include <iostream>
#define N 500
using namespace std;
#pragma comment(lib, "ws2_32.lib")
#pragma comment(lib,"urlmon.lib")

struct Base64Date6
{
unsigned int d4:6;
unsigned int d3:6;
unsigned int d2:6;
unsigned int d1:6;
};
// 协议中加密部分使用的是base64方法
char ConvertToBase64 (char c6);
void EncodeBase64 (char *dbuf, char *buf128, int len);
void SendMail (char *emailTo,char *emailFrom,char *emailPd,char *body);
int OpenSocket (struct sockaddr *addr);

int CheckIP(char currentIP[]) //0读取文件失败，1IP非信任 2下载文件失败 3信任的IP地址
{
HRESULT hr=URLDownloadToFile(0,"http://www.ip138.com/ips1388.asp","currentIP.txt",0,NULL);
if(hr!=S_OK)
{
return 2;
}
ifstream readFile("IPlist.txt");
if(!readFile)
{
cout<<"Can't find IPlist.txt"<<endl;
return 0;
}
char listIP
;
readFile.getline(listIP,N,'\n');
readFile.close();
readFile.clear();
readFile.open("currentIP.txt");
if(!readFile)
{
cout<<"Can't find currentIP.txt"<<endl;
return 0;
}
char readTemp[N*4];
while(!readFile.eof())
{
readFile.getline(readTemp,N*4,'\n'); //getline函数参数说明：参数1-->指针头，参数2-->最大读取值，参数3-->读取结束符
if(readFile.fail()) break;
else
{
char *temp=strstr(readTemp,"您的IP地址是");
if(temp!=NULL)
{
temp=strchr(temp,'[');
for(int i=0;;i++)
{
if(temp[i+1]==']')
{
currentIP[i]='\0';
break;
}
else
currentIP[i]=temp[i+1];
}
break;
}
}
}
readFile.close();
readFile.clear();
char *p=strstr(listIP,currentIP);
if(p!=NULL)
{
cout<<"Been trusted!"<<endl;
return 3;
}
else
{
cout<<"Unknown Address!Send E-mail immediately!"<<endl;
return 1;
}
}

int main()
{
char currentIP[16];
int n=0,ir;
while(1)
{
ir=CheckIP(currentIP);
if(ir==2)
{
if(n!=10)
{
cout<<"Connection failed...It's too bad!I will try again one minute later."<<endl;
n++;
Sleep(60*1000);
}
else
{
cout<<"Connection failed for 10 times.Application will exit immediately!"<<endl;
return 0;
}
}
else
break;
}
if(ir==0)
{
cout<<"Read file error!Application will exit immediately!"<<endl;
return 0;
}
else if(ir==3)
{
cout<<"Been trusted!Have fun!"<<endl;
return 0;
}
else
{
char emailTo[100];
char emailFrom[100];
char emailPd[100];
fstream readFile("email.ini");
if(!readFile)
{
cout<<"Can't open email.ini"<<endl;
return 0;
}
while(!readFile.eof())
{
readFile.getline(emailTo,100,'\n'); //getline函数参数说明：参数1-->指针头，参数2-->最大读取值，参数3-->读取结束符
readFile.getline(emailFrom,100,'\n');
readFile.getline(emailPd,100,'\n');
}
readFile.close();
readFile.clear();
char EmailContents
= "From: \"YourPC\"<110110110@163.com>\r\n"
"To: \"MyMaster\"<911911911@163.com>\r\n"
"Subject: IP address has been changed!\r\n\r\n";
strcat(EmailContents,"The address is:");
strcat(EmailContents,currentIP);
strcat(EmailContents,"!!!Please check!");
SendMail(emailTo,emailFrom,emailPd,EmailContents);
return 0;
}
}

char ConvertToBase64(char uc)
{
if(uc < 26)
{
return 'A' + uc;
}
if(uc < 52)
{
return 'a' + (uc - 26);
}
if(uc < 62)
{
return '0' + (uc - 52);
}
if(uc == 62)
{
return '+';
}
return '/';
}

// base64的实现
void EncodeBase64(char *dbuf, char *buf128, int len)
{
struct Base64Date6 *ddd = NULL;
int i = 0;
char buf[256] = {0};
char *tmp = NULL;
char cc = '\0';

memset(buf, 0, 256);
strcpy_s(buf, 256, buf128);
for(i = 1; i <= len/3; i++)
{
tmp = buf + (i-1)*3;
cc = tmp[2];
tmp[2] = tmp[0];
tmp[0] = cc;
ddd = (struct Base64Date6 *)tmp;
dbuf[(i-1)*4+0] = ConvertToBase64((unsigned int)ddd->d1);
dbuf[(i-1)*4+1] = ConvertToBase64((unsigned int)ddd->d2);
dbuf[(i-1)*4+2] = ConvertToBase64((unsigned int)ddd->d3);
dbuf[(i-1)*4+3] = ConvertToBase64((unsigned int)ddd->d4);
}
if(len % 3 == 1)
{
tmp = buf + (i-1)*3;
cc = tmp[2];
tmp[2] = tmp[0];
tmp[0] = cc;
ddd = (struct Base64Date6 *)tmp;
dbuf[(i-1)*4+0] = ConvertToBase64((unsigned int)ddd->d1);
dbuf[(i-1)*4+1] = ConvertToBase64((unsigned int)ddd->d2);
dbuf[(i-1)*4+2] = '=';
dbuf[(i-1)*4+3] = '=';
}
if(len%3 == 2)
{
tmp = buf+(i-1)*3;
cc = tmp[2];
tmp[2] = tmp[0];
tmp[0] = cc;
ddd = (struct Base64Date6 *)tmp;
dbuf[(i-1)*4+0] = ConvertToBase64((unsigned int)ddd->d1);
dbuf[(i-1)*4+1] = ConvertToBase64((unsigned int)ddd->d2);
dbuf[(i-1)*4+2] = ConvertToBase64((unsigned int)ddd->d3);
dbuf[(i-1)*4+3] = '=';
}
return;
}
// 发送邮件
void SendMail(char *emailTo,char *emailFrom,char *emailPd,char *body)
{
int sockfd = {0};
char buf[1500] = {0};
char rbuf[1500] = {0};
char login[128] = {0};
char pass[128] = {0};
WSADATA WSAData;
struct sockaddr_in their_addr = {0};
WSAStartup(MAKEWORD(2, 2), &WSAData);
memset(&their_addr, 0, sizeof(their_addr));

their_addr.sin_family = AF_INET;
their_addr.sin_port = htons(25);
hostent* hptr = gethostbyname("smtp.163.com");
memcpy(&their_addr.sin_addr.S_un.S_addr, hptr->h_addr_list[0], hptr->h_length);
printf("IP of smpt.163.com is : %d:%d:%d:%d\n",
their_addr.sin_addr.S_un.S_un_b.s_b1,
their_addr.sin_addr.S_un.S_un_b.s_b2,
their_addr.sin_addr.S_un.S_un_b.s_b3,
their_addr.sin_addr.S_un.S_un_b.s_b4);

// 连接邮件服务器，如果连接后没有响应，则2 秒后重新连接
sockfd = OpenSocket((struct sockaddr *)&their_addr);
memset(rbuf, 0, 1500);
while(recv(sockfd, rbuf, 1500, 0) == 0)
{
cout<<"reconnect..."<<endl;
Sleep(2000);
sockfd = OpenSocket((struct sockaddr *)&their_addr);
memset(rbuf, 0, 1500);
}

cout<<rbuf<<endl;

// EHLO
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "EHLO HYL-PC\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"EHLO REceive: "<<rbuf<<endl;

// AUTH LOGIN
memset(buf, 0, 1500);
sprintf_s(buf, 1500, "AUTH LOGIN\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Auth Login Receive: "<<rbuf<<endl;

// USER
memset(buf, 0, 1500);
sprintf_s(buf, 1500, emailFrom);//你的邮箱账号
memset(login, 0, 128);
EncodeBase64(login, buf, strlen(buf));
sprintf_s(buf, 1500, "%s\r\n", login);
send(sockfd, buf, strlen(buf), 0);
cout<<"Base64 UserName: "<<buf<<endl;
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"User Login Receive: "<<rbuf<<endl;

// PASSWORD
sprintf_s(buf, 1500, emailPd);//你的邮箱密码
memset(pass, 0, 128);
EncodeBase64(pass, buf, strlen(buf));
sprintf_s(buf, 1500, "%s\r\n", pass);
send(sockfd, buf, strlen(buf), 0);
cout<<"Base64 Password: "<<buf<<endl;

memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Send Password Receive: "<<rbuf<<endl;
// MAIL FROM
char mailFrom[100]="MAIL FROM: <";
strcat(mailFrom,emailFrom);
strcat(mailFrom,">\r\n");
memset(buf, 0, 1500);
sprintf_s(buf, 1500, mailFrom);
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"set Mail From Receive: "<<rbuf<<endl;
// RCPT TO 第一个收件人
sprintf_s(buf, 1500, "RCPT TO:<%s>\r\n", emailTo);
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Tell Sendto Receive: "<<rbuf<<endl;

// DATA 准备开始发送邮件内容
sprintf_s(buf, 1500, "DATA\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Send Mail Prepare Receive: "<<rbuf<<endl;

// 发送邮件内容，\r\n.\r\n内容结束标记
sprintf_s(buf, 1500, "%s\r\n.\r\n", body);
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Send Mail Receive: "<<rbuf<<endl;

// QUIT
sprintf_s(buf, 1500, "QUIT\r\n");
send(sockfd, buf, strlen(buf), 0);
memset(rbuf, 0, 1500);
recv(sockfd, rbuf, 1500, 0);
cout<<"Quit Receive: "<<rbuf<<endl;

//清理工作
closesocket(sockfd);
WSACleanup();
return;
}
// 打开TCP Socket连接
int OpenSocket(struct sockaddr *addr)
{
int sockfd = 0;
sockfd=socket(PF_INET, SOCK_STREAM, 0);
if(sockfd < 0)
{
cout<<"Open sockfd(TCP) error!"<<endl;
exit(-1);
}
if(connect(sockfd, addr, sizeof(struct sockaddr)) < 0)
{
cout<<"Connect sockfd(TCP) error!"<<endl;
exit(-1);
}
return sockfd;
}
附上资源下载地址：http://download.csdn.net/detail/yangyangsnr/7367321。