将TCP的CS模型再敲一遍
TCP服务器
1->创建原始的套接字描述符
2->将原始套接字与主机ip绑定
3->将原始套接字设置监听状态
4->接收客户端连接，获取客户端信息，因为原始套接字被用了，所以创建新的套接字描述符用于客户端通信
5->发送接收信息
6->关闭
#include <myhead.h>
#define SERPORT 3456
#define SERIP "192.168.0.102"
#define BACKLOG 5
int main(int argc, const char *argv[])
{
int oldfd = socket(AF_INET,SOCK_STREAM,0);
if(oldfd == -1)
{
perror("socket");
return -1;
}
printf("旧的套接字创建成功\n");
//2.绑定主机的IP和端口号
struct sockaddr_in sin = {
.sin_family = AF_INET,//使用IPv4通信协议族
.sin_port = htons(SERPORT),//设置端口号
.sin_addr.s_addr = inet_addr(SERIP)//设置IP地址为本机地址
};//定义服务器地址结构体变量
if(bind(oldfd,(struct sockaddr *)&sin,sizeof(sin)) == -1)//绑定ip
{
perror("bind");
return -1;
}
printf("绑定成功\n");
if(listen(oldfd,BACKLOG) == -1)//监听客户端需求
{
perror("listen");
return -1;
}
printf("监听成功\n");
char buff[1024];
struct sockaddr_in cin;//定义获取客户端信息结构体
socklen_t cinlen = sizeof(cin);//获取结构体大小
int newfd = accept(oldfd,(struct sockaddr *)&cin,&cinlen);//接收请求，创建新的描述符
if(newfd == -1)
{
perror("accept");
return -1;
}
printf("%s:%d客户端发来连接请求\n",inet_ntoa(cin.sin_addr),ntohs(cin.sin_port));
while(1)
{
memset(buff,0,sizeof(buff));
//int len = read(newfd,buff,sizeof(buff));
int len = recv(newfd,buff,sizeof(buff),0);
printf("读取的信息:%s\n",buff);
if(len == 0)
{
printf("你客户跑了\n");
}
strcat(buff,"520");
//write(newfd,buff,sizeof(buff));
send(newfd,buff,sizeof(buff),0);
memset(buff,0,sizeof(buff));
}
close(oldfd);
close(newfd);
return 0;
}
TCP客户端
1->创建原始套接字描述符
2->可以绑定也可以不绑定，这里就没有绑定了
3->连接服务器，创建结构体用于接收自己的信息，在连接时要带上自己“身份”
4->发送接收信息
5->关闭
#include <myhead.h>
#define SERPORT 3456
#define SERIP "192.168.0.102"
int main(int argc, const char *argv[])
{
int oldfd = socket(AF_INET,SOCK_STREAM,0);
if(oldfd == -1)
{
perror("socket");
return -1;
}
//2.绑定(可选)
//连接服务器
struct sockaddr_in cin = {
.sin_family = AF_INET,//使用IPv4通信协议族
.sin_port = htons(SERPORT),//设置端口号
.sin_addr.s_addr = inet_addr(SERIP)//设置IP地址为本机地址
};//定义服务器地址结构体变量
if(connect(oldfd,(struct sockaddr *)&cin,sizeof(cin)) == -1)
{
perror("connect");
return -1;
}
printf("连接成功\n");
char buff[1024];
while(1)
{
memset(buff,0,sizeof(buff));
printf("客户端发信息");
fgets(buff,sizeof(buff),stdin);
buff[strlen(buff)-1] = '\0';
send(oldfd,buff,sizeof(buff),0);
recv(oldfd,buff,sizeof(buff),0);
printf("收到服务器信息%s\n",buff);
}
close(oldfd);
return 0;
}
UDP服务器中，使用connect函数，实现唯一的客户端与服务器通话
UDP服务器
UDP服务器可以不连接（connect），连接后会与指定的客户端通信，不会接收其他客户端信息
代码中当接收到ccc字符串的时候使用connect函数，就只与发ccc字符串的客户端通信了
#include <myhead.h>
#define SERPORT 8888
#define SERIP "192.168.0.102"
int main(int argc, const char *argv[])
{
int oldfd = socket(AF_INET,SOCK_DGRAM,0);
if(-1 == oldfd)
{
perror("socket");
return -1;
}
struct sockaddr_in sin = {
.sin_family = AF_INET,
.sin_port = htons(SERPORT),
.sin_addr.s_addr = inet_addr(SERIP)
};
if(bind(oldfd,(struct sockaddr*)&sin,sizeof(sin)) == -1)
{
perror("bind");
return -1;
}
struct sockaddr_in cin;
socklen_t cinlen = sizeof(cin);
char buff[100];
while(1)
{
memset(buff,0,sizeof(buff));
int len = recvfrom(oldfd,buff,sizeof(buff),0,(struct sockaddr*)&cin,&cinlen);
if(strcmp(buff,"ccc")==0)
{
connect(oldfd,(struct sockaddr*)&cin,cinlen);
}
if(len == 0)
{
printf("客户端跑了\n");
break;
}
printf("服务器接收到信息:%s\n",buff);
//strcat(buff,"666");
//sendto(oldfd,buff,sizeof(buff),0,(struct sockaddr*)&sin,sizeof(sin));
//printf("发送成功\n");
//memset(buff,0,sizeof(buff));
}
close(oldfd);
return 0;
}
UDP客户端
#include <myhead.h>
#define CLIPORT 8888
#define CLIIP "192.168.0.102"
int main(int argc, const char *argv[])
{
int oldfd = socket(AF_INET,SOCK_DGRAM,0);
if(oldfd == -1)
{
perror("socket");
return -1;
}
struct sockaddr_in cin = {
.sin_family = AF_INET,
.sin_port = htons(CLIPORT),
.sin_addr.s_addr = inet_addr(CLIIP)
};
char buff[1024];
while(1)
{
printf("客户端发信息：");
fgets(buff,sizeof(buff),stdin);
sendto(oldfd,buff,sizeof(buff),0,(struct sockaddr*)&cin,sizeof(cin));
printf("发送成功");
}
close(oldfd);
return 0;
}
TCP和UDP的思维导图
