互联网络程序设计实验-实验2

1.实验目标

以C++类封装socket

2.实验原理

类继承体系：

BasicFileSocketUnixSocketTcpSocketUdpSocketUnixStreamClientSocketUnixStreamServerSocketTcpClientSocketTcpServerSocketUdpClientSocketUdpServerSocket 3.实验内容

（1）socket表现为文件描述符

将int socket作为类的成员，类向外暴露各种socket操作 编写如下：

class Socket {

public:

Socket();

virtual ~Socket(); virtual int Socket(); private:

int sin_size; int sockfd,new_fd; unsigned short port;

struct sockaddr_in my_addr,their_addr,get_addr;

};

void SetPort(unsigned short in_port); bool Bind();

void SetRemotePort(unsigned short in_port); unsigned short GetRemotePort(); void GetRemoteAddrees(char *addrees); bool Connect(); void Listen(); void Accept();

int Send(const char *buf,int len); int Sendto(const char *buf,int len); int Recv(char *buf,int len); int Recvfrom(char *buf,int len); void Close();

//

class TCP:public Socket { };

class UDP:public Socket { };

class SCTP:public Socket {

public:

int Socket();

bool Connect(); public:

int Socket();

public:

int Socket(); bool Connect();

}; #endif

socket的类型很多 SOCK_STREAM SOCK_DGRAM SOCK_SEQPACKET AF_INET TCP|SCTP UDP SCTP AF_INET6 TCP|SCTP UDP SCTP AF_LOCAL yes yes yes 以一种统一的形式封装各种不同类型的socket 处理如下：

//定义

class TCP:public Socket {

};

public:

int Socket(); bool Connect();

class UDP:public Socket { };

class SCTP:public Socket {

public:

int Socket();

bool Connect(); public:

int Socket();

}; //函数

int UDP::Socket() {

sockfd = socket(AF_INET ,SOCK_DGRAM, 0); return sockfd; }

int TCP::Socket() {

sockfd = socket(AF_INET,SOCK_STREAM, 0); return sockfd; }

int SCTP::Socket() { }

sockfd = socket(AF_INET,SOCK_SEQPAKET, 0); return sockfd;

（2）考察socket的连接函数

socket的地址族不一样，导致sockaddr结构是不一样的，虽然tcp/sctp这样的面向连接的协议可能都会有connect这样的函数，并且连接的动作都差不多，但是connect函数的servaddr参数是不一样的。如何解决相似动作，但是参数类型不同？ 处理如下：

bool TCP::Connect() {

if(connect(sockfd,(struct sockaddr *)&their_addr, sizeof(struct sockaddr))==-1)

return false;

return true; }

bool SCTP::Connect() {

if(connect(sockfd,(const struct sockaddr *)&their_addr, sizeof(struct sockaddr))==-1) return false;

return true; }

附录1 socket.h

#ifndef #define

#include #include #include #include #include #include #include #include #include #include #include #include #include

#include #include #include using namespace std; class Socket {

private:

int sin_size; int sockfd,new_fd; unsigned short port;

struct sockaddr_in my_addr,their_addr,get_addr;

SOCKET__H SOCKET__H

};

public:

Socket();

virtual ~Socket(); virtual int Socket();

void SetPort(unsigned short in_port); bool Bind();

void SetRemotePort(unsigned short in_port); unsigned short GetRemotePort(); void GetRemoteAddrees(char *addrees); bool Connect(); void Listen(); void Accept();

int Send(const char *buf,int len); int Sendto(const char *buf,int len); int Recv(char *buf,int len); int Recvfrom(char *buf,int len); void Close();

//

class TCP:public Socket { };

class UDP:public Socket { };

class SCTP:public Socket {

public:

int Socket();

bool Connect(); public:

int Socket();

public:

int Socket(); bool Connect();

}; #endif

附录2 socket.cpp

#include \"server.h\" Socket::Socket() {

}

Socket::~Socket() { Close(); }

int UDP::Socket() {

sockfd = socket(AF_INET ,SOCK_DGRAM, 0); return sockfd; }

int TCP::Socket() {

sockfd = socket(AF_INET,SOCK_STREAM, 0); return sockfd; }

int SCTP::Socket() {

sockfd = socket(AF_INET,SOCK_SEQPAKET, 0); return sockfd;

}

int Socket::Socket() {

sockfd = socket(AF_INET,SOCK_STREAM, 0); return sockfd; }

void Socket::SetPort(unsigned short in_port) {

struct hostent *host;

host=gethostbyname(\"192.168.0.225\"); my_addr.sin_family = AF_INET; port = in_port;

my_addr.sin_port = htons(port);

my_addr.sin_addr = *((struct in_addr *)host->h_addr);

bzero(&(my_addr.sin_zero),8); }

void Socket::SetRemotePort(unsigned short in_port) {

their_addr.sin_port=htons(in_port); }

unsigned short Socket::GetRemotePort() {

return ntohs(get_addr.sin_port); }

bool Socket::Bind() {

if(bind(sockfd,(struct sockaddr *)&my_addr,sizeof(struct sockaddr))==-1) {

perror(\"bind err\\n\"); return false;

}

return true; }

int Socket::Recvfrom(char *buf,int len) {

int numbytes;

socklen_t addr_len = sizeof(get_addr);

numbytes = recvfrom(sockfd,buf,len,0,(struct sockaddr *)&get_addr,&addr_len); if(numbytes == -1) {

return false; }

buf[numbytes] = '\\0'; return numbytes; }

int Socket::Sendto(const char *buf,int len) {

return sendto(sockfd,buf,len,0,(struct sockaddr *)&their_addr,sizeof(struct sockaddr)); }

void Socket::Close() {

close(sockfd); close(new_fd); }

void Socket::Listen() {

if(listen(sockfd,10)==-1) cout<<\"listen err!\\n\"; }

void Socket::Accept() {

socklen_t size = sizeof(struct sockaddr_in);

new_fd = accept(sockfd,(struct sockaddr *)&get_addr,&size); if(new_fd==-1)

{

perror(\"accept err!\\n\"); exit(1); }

}

int Socket::Recv(char *buf,int len) {

return recv(new_fd,buf,len,0); }

int Socket::Send(const char * buf, int len) {

return send(new_fd,buf,len,0); }

bool TCP::Connect() {

if(connect(sockfd,(struct sockaddr *)&their_addr, sizeof(struct sockaddr))==-1) return false;

return true; }

bool SCTP::Connect() {

if(connect(sockfd,(const struct sockaddr *)&their_addr, sizeof(struct sockaddr))==-1) return false;

return true; }