c++中的Telnet客户端错误
Telnet client error in c++
telnet客户端代码为:
在此处输入代码
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>
#include <termios.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <arpa/telnet.h>
#define DO 0xfd
#define WONT 0xfc
#define WILL 0xfb
#define DONT 0xfe
#define CMD 0xff
#define CMD_ECHO 1
#define CMD_WINDOW_SIZE 31
void negotiate(int sock, unsigned char *buf, int len) {
int i;
if (buf[1] == DO && buf[2] == CMD_WINDOW_SIZE) {
unsigned char tmp1[10] = {255, 251, 31};
if (send(sock, tmp1, 3 , 0) < 0)
exit(1);
unsigned char tmp2[10] = {255, 250, 31, 0, 80, 0, 24, 255, 240};
if (send(sock, tmp2, 9, 0) < 0)
exit(1);
return;
}
for (i = 0; i < len; i++) {
if (buf[i] == DO)
buf[i] = WONT;
else if (buf[i] == WILL)
buf[i] = DO;
}
if (send(sock, buf, len , 0) < 0)
exit(1);
}
static struct termios tin;
static void terminal_set(void) {
// save terminal configuration
tcgetattr(STDIN_FILENO, &tin);
static struct termios tlocal;
memcpy(&tlocal, &tin, sizeof(tin));
cfmakeraw(&tlocal);
tcsetattr(STDIN_FILENO,TCSANOW,&tlocal);
}
static void terminal_reset(void) {
// restore terminal upon exit
tcsetattr(STDIN_FILENO,TCSANOW,&tin);
}
#define BUFLEN 20
int main(int argc , char *argv[]) {
int sock;
struct sockaddr_in server;
unsigned char buf[BUFLEN + 1];
int len;
int i;
if (argc < 2 || argc > 3) {
printf("Usage: %s address [port]n", argv[0]);
return 1;
}
int port;
if (argc == 3)
port = atoi(argv[2]);
//Create socket
sock = socket(AF_INET , SOCK_STREAM , 0);
if (sock == -1) {
perror("Could not create socket. Error");
return 1;
}
server.sin_addr.s_addr = inet_addr(argv[1]);
server.sin_family = AF_INET;
server.sin_port = htons(port);
//Connect to remote server
if (connect(sock , (struct sockaddr*)&server , sizeof(server)) < 0) {
perror("connect failed. Error");
return 1;
}
puts("Connected...n");
// set terminal
terminal_set();
atexit(terminal_reset);
struct timeval ts;
ts.tv_sec = 1; // 1 second
ts.tv_usec = 0;
while (1) {
// select setup
fd_set fds;
FD_ZERO(&fds);
if (sock != 0)
FD_SET(sock, &fds);
FD_SET(0, &fds);
// wait for data
int nready = select(sock + 1, &fds, (fd_set *) 0, (fd_set *) 0, &ts);
if (nready < 0) {
perror("select. Error");
return 1;
}
else if (nready == 0) {
ts.tv_sec = 1; // 1 second
ts.tv_usec = 0;
}
else if (sock != 0 && FD_ISSET(sock, &fds)) {
// start by reading a single byte
int rv;
if ((rv = recv(sock , buf , 1 , 0)) < 0)
return 1;
else if (rv == 0) {
printf("Connection closed by the remote endnr");
return 0;
}
if (buf[0] == CMD) {
// read 2 more bytes
len = recv(sock , buf + 1 , 2 , 0);
if (len < 0)
return 1;
else if (len == 0) {
printf("Connection closed by the remote endnr");
return 0;
}
negotiate(sock, buf, 3);
}
else {
len = 1;
buf[len] = ' ';
printf("%s", buf);
fflush(0);
}
}
else if (FD_ISSET(0, &fds)) {
buf[0] = getc(stdin); //fgets(buf, 1, stdin);
if (send(sock, buf, 1, 0) < 0)
return 1;
if (buf[0] == 'n') // with the terminal in raw mode we need to force a LF
putchar('r');
}
}
close(sock);
return 0;
}
而服务器代码为:
enter code here
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <cstring>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netdb.h>
int main(int argc , char *argv[])
{
int socket_desc , new_socket , c;
struct sockaddr_in server ,client;
char *message;
//create socket;
socket_desc = socket(AF_INET , SOCK_STREAM , 0);
if (socket_desc == -1)
{printf("Could not create socket");
}
//prepare sock addr structure
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
server.sin_port = htons( 8888 );
//bind
if(bind(socket_desc, (struct sockaddr *)&server , sizeof(&server)) < 0)
{
printf("bind failed");
}
printf("Bind done");
//Listen
listen(socket_desc , 3);
//accept incoming connection
printf("Waiting for incoming connection ... ");
c =sizeof(struct sockaddr_in);
new_socket = accept(socket_desc, (struct sockaddr *)&client,sizeof(&client));
while(new_socket < 0);
{
puts("Connection Accepted");
message = "Hello Client ...Recieved your message n";
write(new_socket , message , strlen(message));
}
if (new_socket < 0)
{
perror("accept failed");
return 1;
}
return 0;
}
从命令行执行程序时:
/服务器8000
/telnet_client 127.0.0.1 8000
telnet客户端给出错误"连接失败。错误:连接被拒绝"请帮助如何成功执行程序
您正在侦听8888端口,但试图连接到8000。尽管您正在将8000参数传递给服务器程序,但您并没有对其进行任何操作
server.sin_port = htons( 8888 );
而是处理传递给程序的参数
if ( argc != 2)
err_quit("usage: server <port>"); // or maybe use some default
//...
server.sin_port = htons( atoi( argv[1]) );
在服务器中
int port = 8888;
...
if (argc < 1 || argc > 2) {
printf("Usage: %s [port(default=8888)] n", argv[0]);
return 1;
}
port = (argc == 2) ? atoi(argv[1]);
...
server.sin_port = htons(port);
...
相关文章:
- 当客户端在 write() 期间终止连接时,由对等套接字错误重置连接
- Freeopcua C++ 客户端和 Python Opcua 的组合会在 getChild() 上抛出错误
- Websocket 客户端在 C++ 中使用 boost::Beast - 在写入操作时抛出错误
- 编译 Java TD 客户端时出现构建错误
- 服务器客户端通过原始数据错误C 发送接收结构
- 在运行Visual Studio中用C 编写的Oracle DB客户端时,我会收到错误32104
- 使用PPConsul(C 的领事客户端)构建错误的C 项目
- UDP 客户端到 UDP 服务器的问题,出现 10057 错误
- Winsock客户端在本地网络上发生错误11004
- 从客户端读取时出现套接字错误
- C# 客户端到C++服务器 Tcp 套接字连接错误
- 套接字C++:按 F5 后出现客户端错误
- 使用ACE_dll动态加载客户端C++dll,错误为未处理的异常
- DX9从全屏切换到窗口,给出了错误的客户端区域
- 尝试从客户端接收时出现分段错误
- 在Windows上编译Mongo DB客户端示例时,链接器错误
- 编译基于 sCrypt 的加密货币 QT 客户端时,抛出常见错误
- 为什么我在一段时间后不断出现MySQL客户端内存不足错误.
- 自定义NTP客户端获取错误的时间戳
- 运行使用gSOAP创建的web服务客户端时发生SSL错误