TCP/UDP协议传输

TCP

客户端

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <string.h>
 
//宏定义错误输出格式>>>>类比封装函数
#define ERR_MSG(msg) do{\
    fprintf(stderr,"line:%d",__LINE__);\
    perror("msg");\
}while(0);
 
#define IP "192.168.124.62"
#define PORT 8888
int main(int argc, const char *argv[])
{
    //创建流式套接字
    int cfd = socket(AF_INET,SOCK_STREAM,0);
    if(cfd<0)
    {
        ERR_MSG("scoket");
        return -1;
    }
    printf("创建流式套接字成功 cfd %d\n",cfd);
 
    //填充服务器的地址信息结构体
    //真实的地址信息结构体根据地址族来制定
    struct sockaddr_in sin;
    //写一个包含ip端口的构造体
    sin.sin_family      = AF_INET;
    sin.sin_port        = htons(PORT);
    sin.sin_addr.s_addr = inet_addr(IP);
    //连接指定的服务器
    if(connect(cfd,(struct sockaddr*)&sin,sizeof(sin))<0)
    {
        ERR_MSG("connect");
        return -1;
    }
    printf("[%s:%d]服务器连接成功\n",IP,PORT);
 
    char buf[128];
    ssize_t res;
    while(1)
    {
        bzero(buf,sizeof(buf));
        //发送
        printf("请输入>>>>");
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf)-1] = '\0';                                    
 
        if(send(cfd,buf,sizeof(buf),0)<0)
        {
            ERR_MSG("send");
            return -1;
        }
        printf("发送成功\n");
        //接收
        bzero(buf,sizeof(buf));
        res = recv(cfd,buf,sizeof(buf),0);
        if(res < 0)
        {
            ERR_MSG("recv");
            return -1;
        }else if(res == 0)
        {
            printf("[%s:%d]服务器下线\n",IP,PORT);
            break;
        }
        printf("[%s:%d] newfd=%d : %s\n",IP,PORT,cfd,buf);
    }
    close (cfd);
 
    return 0;
}

服务器端

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <string.h>
 
#define PORT 8888   //1014~49151
#define IP "192.168.124.62"
#define ERR_MSG(msg) do{\
    fprintf(stderr,"line:%d",__LINE__);\
    perror(msg);\
}while(0)
int main(int argc, const char *argv[])
{
    //创建流式套接字
    int sfd = socket(AF_INET,SOCK_STREAM,0);
    if(sfd<0)
    {
        ERR_MSG("socket");
            return -1;
    }
    printf("流式套接字创建成功 sfd=%d\n",sfd);
 
    //允许端口快速被复用
    int reuse = 1;
    if(setsockopt(sfd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse))<0)
    {
        ERR_MSG("setsockopt");
        return -1;
    }
    printf("允许端口被重复使用\n");
    //填充服务器的地址信息结构体,给bind函数使用
    //真实的地址信息结构体根据地址族制定,AF_LNET-->>man 7 ipp
    struct sockaddr_in sin;
    sin.sin_family      = AF_INET;
    sin.sin_port        = htons(PORT);
    sin.sin_addr.s_addr = inet_addr(IP);
    //绑定服务器的地址信息,必须绑定
    if(bind(sfd,(struct sockaddr*)&sin,sizeof(sin))<0)
    {
        ERR_MSG("bind");
        return -1;
    }
    printf("绑定成功!\n");
    //将套接字设置尾监听状态
    if(listen(sfd,128)<0)
    {
        ERR_MSG("listen");
        return -1;
    }
    printf("监听成功!\n");
    //获取连接成功的客户端信息,生成一个新的套接字文件描述符
    struct sockaddr_in cin;
    socklen_t addrlen = sizeof(cin);
    int newfd = accept(sfd,(struct sockaddr*)&cin ,&addrlen);
    if(newfd<0)
    {
        ERR_MSG("accept");
        return -1;
    }                                                                            
    printf("[%s:%d] newfd=%d 客户端连接成功\n",\
            inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),newfd);
    //接收
    char buf[128];
    ssize_t res;
    while(1)
    {
        bzero(buf,sizeof(buf));
        res = recv(newfd,&buf,sizeof(buf),0);
        if(res<0)
        {
            ERR_MSG("recv");
            return -1;
        }else if(res == 0)
        {
            printf("[%s:%d]客户端下线\n",\
                    inet_ntoa(cin.sin_addr),ntohs(cin.sin_port));
            break;
        }
 
        printf("[%s:%d]newfd=%d : %s\n",\
                inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),newfd,buf);
        //发送
        printf("请输入>>>>");
        fgets(buf,sizeof(buf),stdin);
        buf[strlen(buf)-1] = '\0';
        if(send(newfd,buf,sizeof(buf),0)<0)
        {
            ERR_MSG("send");
            return -1;
        }
        printf("发送成功\n");
    }
    //关闭
    close (newfd);
    if(close(sfd)<0)
    {
        ERR_MSG("close");
        return -1;
    }
    return 0;
}

UDP

服务器端

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <netinet/in.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>
 
#define PORT 6666
#define IP "192.168.124.62"
#define ERR_MSG(msg) do{\
    fprintf(stderr,"line:%d\n",__LINE__);\
    perror(msg);\
}while(0)
 
 
int main(int argc, const char *argv[])
{
    int fd = socket(AF_INET,SOCK_DGRAM,0);
    if(fd<0)
    {
        ERR_MSG("scoket");
        return -1;
    }
    printf("创建流式套接字成功\n");
 
    //允许端口被重复使用
    int reuse = 1;
    if(setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse))<0)
    {
        ERR_MSG("setsockopt");
        return -1;
    }
    printf("允许端口被重复使用\n");
    //绑定服务器地址信息,必须绑定
    struct sockaddr_in sin;
    sin.sin_family     = AF_INET;
    sin.sin_port       = htons(PORT);
    sin.sin_addr.s_addr= inet_addr(IP);
 
    if(bind(fd,(struct sockaddr*)&sin,sizeof(sin))<0)
 
    {
        ERR_MSG("bind");
        return -1;
    }
    printf("绑定成功\n");
    //接收数据
    char arr[128] = "";
    struct sockaddr_in cin;
    socklen_t addrlen = sizeof(cin);
    while(1)
    {
        bzero(arr,sizeof(arr));//清空arr数据
        if(recvfrom(fd,arr,sizeof(arr),0,(struct sockaddr*)&cin,&addrlen) < 0)
        {
            ERR_MSG("recvfrom");
            return -1;
        }
        printf("[%s:%d] arr=%s\n",\
                inet_ntoa(cin.sin_addr),ntohs(cin.sin_port),arr);
        //发送数据
        strcat(arr,"hello word");
        if(sendto(fd,arr,sizeof(arr),0,\                                            
                    (struct sockaddr*)&cin,sizeof(cin))<0)
        {
            ERR_MSG("sendto");
            return -1;
        }
        printf("发送成功\n");
    }
    close(fd);
    return 0;
}

客户端

#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>
 
#define PORT 6666
#define IP "192.168.124.62"
#define ERR_MSG(msg) do{\
    fprintf(stderr,"line:%d\n",__LINE__);\
    perror(msg);\
}while(0)
 
 
int main(int argc, const char *argv[])
{
    int fd = socket(AF_INET,SOCK_DGRAM,0);
    if(fd<0)
    {
        ERR_MSG("scoket");
        return -1;
    }
    printf("创建流式套接字成功cd=%d\n",fd);
 
/*  //允许端口被重复使用
    int reuse = 1;                                                       
    if(setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&reuse,sizeof(reuse))<0)
    {
        ERR_MSG("setsockopt");
        return -1;
    }
    printf("允许端口被重复使用\n");
*/  //绑定服务器地址信息,必须绑定
    struct sockaddr_in sin;
    sin.sin_family     = AF_INET;
    sin.sin_port       = htons(PORT);
    sin.sin_addr.s_addr= inet_addr(IP);
/*  //绑定IP及端口号
    if(bind(fd,(struct sockaddr*)&sin,sizeof(sin))<0)   
    {
        ERR_MSG("bind");
        return -1;
    }
    printf("绑定成功\n");
*/
    char arr[128];
    struct sockaddr_in cin;
    socklen_t addrlen = sizeof(arr);
    while(1)
    {
        bzero(arr,sizeof(arr));//清空arr数据
        //发送数据
        printf("请输入数据>>>>>");
        fgets(arr,sizeof(arr),stdin);
        arr[strlen(arr)-1] = '\0';
        if(sendto(fd,arr,sizeof(arr),0,\
                    (struct sockaddr*)&sin,sizeof(sin))<0)
        {
            ERR_MSG("sendto");
            return -1;
        }
        printf("发送成功\n");
        bzero(arr,sizeof(arr));                                                 
        //接收数据
        if(recvfrom(fd,arr,sizeof(arr),0,\
                    (struct sockaddr*)&cin,&addrlen)<0)
        {
            ERR_MSG("recvfrom");
            return -1;
        }
        printf("[%s:%d] arr=%s\n",\
                inet_ntoa(sin.sin_addr),ntohs(sin.sin_port),arr);
    }
    close(fd);
    return 0;
}