TCP Socket Port Check

写了两个小程序，主要是用于linux和windows下TCP端口的检测，自带的telnet无法满足我批量检测的需要，在我眼里这类端口检测程序最为关键的是超时的限制，若端口不能却要老久才返回结果，有点不爽，在不改系统默认超时时间的前提上，引入socket的非阻塞模式达到超时限制的目的，下面是具体程序

1. windows下的tcp端口检测程序

简介：引入select模式作为超时限制

 //TCP Port Check program in windows
 
 #include <stdio.h>
 #include <winsock2.h>
 
 #pragma comment(lib,"ws2_32.lib")
 
 int main(int argc, char *argv[])
 {
     SOCKET sockfd;
     SOCKADDR_IN sockaddr;
     int port;
     unsigned long ip;
     WSADATA wsa;
     int timeout=,ret;
     struct timeval tv;
     struct fd_set fs;
     unsigned long ul = ;
 
     if(argc != )
     {
         printf("Usage: %s IP Port TimeOut\n",argv[]);
         return -;
     }
     if((ip=inet_addr(argv[]))==INADDR_NONE)
     {
         printf("IP Address Error\n");
         return -;
     }
     if((port=atoi(argv[]))==)
     {
         printf("Port Error\n");
         return -;
     }
     if((timeout=atoi(argv[]))==)
     {
         printf("Timeout Error\n");
         return -;
     }
     WSAStartup(MAKEWORD(,),&wsa);    //initialize Ws2_32.dll
 
     if((sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) <= )    //create a tcp socket
     {
         printf("Create socket fail!\n");
         return -;
     }
     //socket non-block mode set
     if((ret = ioctlsocket(sockfd, FIONBIO, (unsigned long*)&ul))==SOCKET_ERROR)
     {
         closesocket(sockfd);
         return -;
     }
     sockaddr.sin_family = AF_INET;
     sockaddr.sin_port = htons(port);
     sockaddr.sin_addr.S_un.S_addr = inet_addr(argv[]);
 
     //connect to target ip with port
     connect(sockfd, (SOCKADDR *)&sockaddr, sizeof(sockaddr));
 
     tv.tv_sec = timeout;
     tv.tv_usec = ;
     FD_ZERO(&fs);
     FD_SET(sockfd,&fs);
     ret = select(sockfd+,NULL,&fs,NULL,&tv);
     if(ret<)
     {
         printf("Select Error\n");
         closesocket(sockfd);
         return -;
     }
     else if(ret == )
     {
         printf(" %s %d Connect fail!\n",argv[],port);
         closesocket(sockfd);
         return -;
     }
     else
     {
         printf(" %s %d Connected success!\n",argv[],port);
         closesocket(sockfd);
     }
     WSACleanup(); //clean up Ws2_32.dll
     return ;
 }

2. Linux下TCP端口检测程序

#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <netdb.h>
#include <time.h>
#include <errno.h>
int main(int argc, char *argv[])
{
        int sockfd=socket(AF_INET,SOCK_STREAM,);
        struct sockaddr_in client;
        char ip[];
        int port;
        int timeout;
        struct timeval tv;
        if(argc != )
        {
                printf("Usage : %s ip port timeout\n", argv[]);
                exit();
        }
        strcpy(ip, argv[]);
        port = atoi(argv[]);
        timeout = atoi(argv[]);
 
        bzero(&client, sizeof(struct sockaddr_in));
        client.sin_family = AF_INET;
        client.sin_addr.s_addr = inet_addr(ip);
        client.sin_port = htons(port);
 
        tv.tv_sec = ;
        tv.tv_usec = ;
 
        //set timeout with setsockopt
        if(setsockopt(sockfd,SOL_SOCKET,SO_RCVTIMEO,(char*)&tv, sizeof(tv))<)
        {
            perror("setsockopt failed\n");
            exit();
        }
 
        if(setsockopt(sockfd,SOL_SOCKET,SO_SNDTIMEO,(char*)&tv, sizeof(tv))<)
        {
            perror("setsockopt failed\n");
            exit();
        }
        if(!connect(sockfd,(struct sockaddr*)&client,sizeof(struct sockaddr_in)))
        {
                printf("connect ok\n");
 
        }else{
                printf("connect fail\n");
        }
    close(sockfd);
        return ;
}

3. 总结

代码不难，关键是能提高效率，有时候简单的东西反而更好，继续努力