socket服务端

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <pthread.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <termios.h>
#include <sys/time.h>
#include <sys/timeb.h>
#include <stdarg.h>
#include <netdb.h>

#define SER_IP "127.0.0.1" /*服务器的IP地址*/

int read_socket(int socket_id, char *pbuf, int len);
int write_socket(int socket_id, char *pbuf, int len);

int main(int argc, char ** argv) /*服务端程序*/
{
    pid_t pid;
    char ip_buf[32];
    char readbuf[1024];
    int sockfd = -1; /*监听套接字*/
    int newfd = -1; /*连接套接字*/
    int ret = -1;
    int opt = 1;
    int len;
    int i=0;
    int read_count = 1; /*读取次数*/
    struct sockaddr_in seraddr; /*用来保存服务器自己的ip地址和端口号的*/
    struct sockaddr_in cliaddr; /*用来保存连接过来的客户的ip地址和端口号的*/
    struct sockaddr_in bindaddr; /*用来保存连接过来的客户的ip地址和端口号的*/
    struct sockaddr lbindaddr;

    memset(ip_buf, 0, sizeof(ip_buf));
    memset(readbuf, 0, sizeof(readbuf));

    memset(&seraddr, 0, sizeof(seraddr));
    memset(&cliaddr, 0, sizeof(cliaddr));
    memset(&bindaddr, 0, sizeof(bindaddr));
    memset(&lbindaddr, 0, sizeof(lbindaddr));

    sockfd = socket(AF_INET, SOCK_STREAM, 0); /*创建连接套接字,TCP协议*/
    if(sockfd < 0)
    {
        return -1;
    }
    setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)); /*将服务端设置具有端口号可以重复*/

    seraddr.sin_family = AF_INET; /*指定服务器地址协议族*/
    seraddr.sin_port = htons(4989);     /*指定要监听的服务器的端口号*/
    /*seraddr.sin_addr.s_addr = INADDR_ANY;*/ /*指定要监听的服务器的ip：0.0.0.0:则客户端可连 127.0.0.1 和 真实的主机地址*/

    char * hostname = NULL;
    hostname = getenv("HOST");
    if(hostname == NULL)
    {
        printf("HOST环境变量不存在!\n");
        exit(-1);
    }
    struct hostent * myhost;
    myhost = gethostbyname(hostname);
    if(myhost == NULL)
    {
        printf("myhost is null!\n");
        exit(-1);
    }
    bcopy(myhost->h_addr, &seraddr.sin_addr, myhost->h_length);
    char ipbuf[128];
    memset(ipbuf, 0, sizeof(ipbuf));
    inet_ntop(AF_INET, &seraddr.sin_addr.s_addr, ipbuf, sizeof(ipbuf));
    printf("主机名=[%s],IP地址=[%s]\n", myhost->h_name, ipbuf);
    printf("IP地址=[%s]\n", ipbuf);

    ret = bind(sockfd, (struct sockaddr*)&seraddr, sizeof(struct sockaddr)); /*将IP地址，端口号和文件绑定,为套接字命名*/
    if(ret < 0)
    {
        printf("bind err! ret = [%d]\n", ret);
        return -1;
    }

    ret = listen(sockfd, 10); /*监听*/
    if(ret < 0)
    {
        return -1;
    }

    while(1)
  {
          printf("等待客户端连接.....\n");
            len = sizeof(cliaddr); /*值-结果参数*/
            /*if((newfd=accept(sockfd,(struct sockaddr *)&cliaddr,(socklen_t *)&len))==-1)*/
            if((newfd=accept(sockfd, (struct sockaddr *)NULL, (socklen_t *)NULL)) == -1) /*不关心客户端标识*/
      {
          perror("accept() failed");
          exit(1);
      }
      if((pid=fork())>0)
      {
          close(newfd);
          continue;
      }
      else if(pid==0)
      {
          close(sockfd);
          /*
          memset(ip_buf, 0, sizeof(ip_buf));
                    inet_ntop(AF_INET, &cliaddr.sin_addr.s_addr, ip_buf, sizeof(ip_buf));
                    printf("客户IP=[%s]\n", ip_buf);
                    printf("客户PORT=[%d]\n", ntohs(cliaddr.sin_port));
                    */

                    char    serv_ip[20];
                    char    guest_ip[20];
                  struct sockaddr_in serv;
                  struct sockaddr_in guest;
                  socklen_t serv_len = sizeof(serv);
                  socklen_t guest_len = sizeof(guest);

                  getsockname(newfd, (struct sockaddr *)&serv, &guest_len);
                  getpeername(newfd, (struct sockaddr *)&guest, &serv_len);

                  inet_ntop(AF_INET, &guest.sin_addr.s_addr, guest_ip, sizeof(guest_ip));
                  inet_ntop(AF_INET, &serv.sin_addr.s_addr, serv_ip, sizeof(serv_ip));
                  printf("服务端IP和PORT[%s]:[%d]\n", serv_ip, ntohs(serv.sin_port));
                  printf("客户端IP和PORT[%s]:[%d]\n", guest_ip, ntohs(guest.sin_port));

                    /*ret = write(newfd, "OK", sizeof("OK"));*/ /*告诉客户端，服务器OK了*/
                    while(1)
                    {
                            printf("服务器写入套接字的内容：\n");
                            memset(readbuf, 0, sizeof(readbuf));
                            ret = read(STDIN_FILENO, readbuf, sizeof(readbuf));
                            printf("read=[%s] ret = [%d]\n", readbuf, ret);

                            ret = write(newfd, readbuf, strlen(readbuf));
                            printf("write=[%s] ret = [%d]\n", readbuf, ret);
                    }

                    close(newfd);
          exit(0);
      }
      else
      {
          printf("fork() failed");
          exit(0);
      }
  }
  close(sockfd);

    return 0;
}


/*确保读取指定长度的字符*/
ssize_t readn(int fd, void * ptr, size_t n)
{
        size_t nleft;
        ssize_t nread;

        nleft = n;
        while(nleft > 0)
        {
                if((nread = read(fd, ptr, nleft)) < 0)
                {
                        if(nleft == n)
                                return -1;
                        else
                                break;
                }
                else if(nread == 0)
                {
                        break;
                }
                nleft -= nread;
                ptr += nread;
        }
        return(n - nleft);
}


/*确保写入指定长度的字符*/
ssize_t writen(int fd, sonst void * ptr, size_t n)
{
        size_t nleft;
        ssize_t nwrte;

        nleft = n;
        while(nleft > 0)
        {
                if((nwrte = write(fd, ptr, nleft)) < 0)
                {
                        if(nleft == n)
                                return -1;
                        else
                                break;
                }
                else if(nwrte == 0)
                {
                        break;
                }
                nleft -= nwrte;
                ptr += nwrte;
        }
        return(n - nleft);
}


/***********************************************************
* 函 数 名：read_socket
* 功能描述: 读socket
* 输入参数：
* 输出参数：
* 返    回：
* 流程描述：
* 说明：
* 修改记录:
* [修改人] [日期] - [描述]
***********************************************************/
int read_socket(int socket_id, char *pbuf, int len){
    int num;
    int i;

    if(len <= 0) {
        return     read(socket_id, pbuf, sizeof(pbuf));
    }

    i = 0;
    do{
        num = read(socket_id, &(pbuf[i]), len - i);
        if (num <= 0){
            /* LOG: Read socket error exit. */
            return(-1);
        }
        i += num;
    } while (i < len);

    return(i);
}

/***********************************************************
* 函 数 名：write_socket
* 功能描述: 写socket
* 输入参数：
* 输出参数：
* 返    回：
* 流程描述：
* 说明：
* 修改记录:
* [修改人] [日期] - [描述]
***********************************************************/
int write_socket(int socket_id, char *pbuf, int len){
    int num;
    int i;

    if (len <= 0) return(0);

    i = 0;
    do{
        num = write(socket_id, &(pbuf[i]), len - i);
        if (num < 0){
            /* LOG: Write socket error exit. */
            return(-1);
        }
        i += num;
    } while (i < len);

    return(i);
}