Linux伪终端 telnet源码

文章由LinuxBoy分享于2019-04-01 04:04:00热评（12）

Linux伪终端 telnet源码

pty_fun.cpp

#include "pty_fun.h"
int ptym_open(char *pts_name, int pts_namesz)
{
char *ptr;
char fdm;
/*
*return the name of the master device so that on failure
*the caller can print an error message. Null terminate to
*handle case where string lenth > pts_namesz
* */
strncpy(pts_name, "/dev/ptmx", pts_namesz);
pts_name[pts_namesz - 1] = '\0';
fdm = posix_openpt(O_RDWR);
if (fdm < 0)
return OPEN_PTY_ERR;
if (grantpt(fdm) < 0)
{
close(fdm);
return GRANT_PTY_ERR;
}
if (unlockpt(fdm) < 0)
{
close(fdm);
return UNLOCK_PTY_ERR;
}
if ((ptr = ptsname(fdm)) == NULL)
{
close(fdm);
return GET_PTYS_NAME_ERR;
}
strncpy(pts_name, ptr, pts_namesz);
pts_name[pts_namesz - 1] = '\0';
return fdm;
}
int ptys_open(char *pts_name)
{
int fds;
if ((fds = open(pts_name, O_RDWR)) < 0)
return OPEN_PTYS_ERR;
return fds;
}
int pty_fork(int *ptrfdm, char *slave_name, int slave_namesz,
const struct termios *slave_termiors,
const struct winsize *slave_winsize, pid_t *ppid)
{
int fdm, fds;
pid_t pid;
char pts_name[20];
if ((fdm = ptym_open(pts_name, sizeof(pts_name))) < 0)
{
return fdm;
}
if (slave_name != NULL)
{
strncpy(slave_name, pts_name, slave_namesz);
slave_name[slave_namesz - 1] = '\0';
}
if ((pid = fork()) < 0)
{
return FORK_ERR;
}
else if (pid == 0)
{
if (setsid() < 0)
{
return SETSID_ERR;
}
if ((fds = ptys_open(pts_name)) < 0)
{
close(fdm);
return OPEN_PTYS_ERR;
}
#ifdef TIOCSCTTY
if (ioctl(fds, TIOCSCTTY, (char *) 0) < 0)
return TIOCSCTTY_ERR;
#endif
// if (slave_termiors != NULL)
// {
// if (tcsetattr(fds, TCSANOW, slave_termiors) < 0)
// return INIT_ATTR_ERR;
// }
// if (slave_winsize != NULL)
// {
// if (ioctl(fds, TIOCSWINSZ, slave_winsize) < 0)
// return INIT_ATTR_ERR;
// }
if (dup2(fds, STDIN_FILENO) != STDIN_FILENO)
return DUP_STDIN_ERR;
if (dup2(fds, STDOUT_FILENO) != STDOUT_FILENO)
return DUP_STDOUT_ERR;
if (dup2(fds, STDERR_FILENO) != STDERR_FILENO)
return DUP_STDERR_ERR;
if (fds != STDIN_FILENO && fds != STDOUT_FILENO && fds != STDERR_FILENO)
{
close(fds);
}
*ppid = 0;
return 0;
}
else
{
*ptrfdm =fdm;
*ppid = pid;
return 0;
}
}

pty_fun.h

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <linux/limits.h>
#include <features.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <fcntl.h>
//master pty
#ifndef OPEN_PTY_ERR
#define OPEN_PTY_ERR -1
#endif
#ifndef GRANT_PTY_ERR
#define GRANT_PTY_ERR -2
#endif
#ifndef UNLOCK_PTY_ERR
#define UNLOCK_PTY_ERR -3
#endif
#ifndef GET_PTYS_NAME_ERR
#define GET_PTYS_NAME_ERR -4
#endif
//pty slave
#ifndef OPEN_PTYS_ERR
#define OPEN_PTYS_ERR -5
#endif
#ifndef FORK_ERR
#define FORK_ERR -6
#endif
#ifndef SETSID_ERR
#define SETSID_ERR -7
#endif
#ifndef TIOCSCTTY_ERR
#define TIOCSCTTY_ERR -8
#endif
#ifndef INIT_ATTR_ERR
#define INIT_ATTR_ERR -9
#endif
#ifndef DUP_STDIN_ERR
#define DUP_STDIN_ERR -10
#endif
#ifndef DUP_STDOUT_ERR
#define DUP_STDOUT_ERR -11
#endif
#ifndef DUP_STDERR_ERR
#define DUP_STDERR_ERR -12
#endif
int ptym_open(char *pts_name, int pts_namesz);
int ptys_open(char *pts_name);
int pty_fork(int *ptrfdm, char *slave_name, int slave_namesz,
const struct termios *slave_termiors,
const struct winsize *slave_winsize, pid_t *ppid);

telnetserver.cpp

#include <stdarg.h>
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#include <errno.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <resolv.h>
#include <arpa/inet.h>
#include <stdlib.h>
#include <signal.h>
#include <getopt.h>
#include <pthread.h>
#include "pty_fun.h"
#define DEFAULTIP "127.0.0.1"
#define DEFAULTPORT "20013"
#define DEFAULTBACK "10"
#define DEFAULTDIR "/root"
#define DEFAULTLOG "/tmp/telnet-server.log"
#define PTY_NAME_SIZE 20
#define MAX_BUFSIZE 512
typedef struct thread_arg
{
int pty;
int sockfd;
} thread_arg;
void prterrmsg(char *msg);
#define prterrmsg(msg) { perror(msg); abort(); }
void wrterrmsg(char *msg);
#define wrterrmsg(msg) { fputs(msg, logfp); fputs(strerror(errno), logfp);fflush(logfp); abort(); }
void prtinfomsg(char *msg);
#define prtinfomsg(msg) { fputs(msg, stdout); }
void wrtinfomsg(char *msg);
#define wrtinfomsg(msg) { fputs(msg, logfp); fflush(logfp);}
#define MAXBUF 1024
char buffer[MAXBUF + 1];
char *host = 0;
char *port = 0;
char *back = 0;
char *dirroot = 0;
char *logdir = 0;
unsigned char daemon_y_n = 0;
FILE *logfp;
#define MAXPATH 150
/*------------------------------------------------------
*--- AllocateMemory - 分配空间并把d所指的内容复制
*------------------------------------------------------
*/
void AllocateMemory(char **s, int l, char *d)
{
*s = malloc(l + 1);
bzero(*s, l + 1);
memcpy(*s, d, l);
}
/*------------------------------------------------------
*--- getoption - 分析取出程序的参数
*------------------------------------------------------
*/
void getoption(int argc, char **argv)
{
int c, len;
char *p = 0;
opterr = 0;
while (1)
{
int option_index = 0;
static struct option long_options[] =
{
{ "host", 1, 0, 0 },
{ "port", 1, 0, 0 },
{ "back", 1, 0, 0 },
{ "dir", 1, 0, 0 },
{ "log", 1, 0, 0 },
{ "daemon", 0, 0, 0 },
{ 0, 0, 0, 0 } };
/* 本程序支持如一些参数：
* --host IP地址或者 -H IP地址
* --port 端口或者 -P 端口
* --back 监听数量或者 -B 监听数量
* --dir 服务默认目录或者 -D 服务默认目录
* --log 日志存放路径或者 -L 日志存放路径
* --daemon 使程序进入后台运行模式
*/
c = getopt_long(argc, argv, "H:P:B:D:L", long_options, &option_index);
if (c == -1 || c == '?')
break;
if (optarg)
len = strlen(optarg);
else
len = 0;
if ((!c && !(strcasecmp(long_options[option_index].name, "host"))) || c
== 'H')
p = host = malloc(len + 1);
else if ((!c && !(strcasecmp(long_options[option_index].name, "port")))
|| c == 'P')
p = port = malloc(len + 1);
else if ((!c && !(strcasecmp(long_options[option_index].name, "back")))
|| c == 'B')
p = back = malloc(len + 1);
else if ((!c && !(strcasecmp(long_options[option_index].name, "dir")))
|| c == 'D')
p = dirroot = malloc(len + 1);
else if ((!c && !(strcasecmp(long_options[option_index].name, "log")))
|| c == 'L')
p = logdir = malloc(len + 1);
else if ((!c
&& !(strcasecmp(long_options[option_index].name, "daemon"))))
{
daemon_y_n = 1;
continue;
}
else
break;
bzero(p, len + 1);
memcpy(p, optarg, len);
}
}
void *thread_recv_add_write_pyt(void *arg)
{
int ret, sockfd, pty;
char buffer[MAX_BUFSIZE];
thread_arg *arg1 = (thread_arg*) arg;
sockfd = arg1->sockfd;
pty = arg1->pty;
while (1)
{
memset(buffer, 0, MAX_BUFSIZE);
ret = recv(sockfd, buffer, MAX_BUFSIZE, 0);
if (ret < 0)
{
continue;
}
printf("%s", buffer);
write(pty, buffer, strlen(buffer));
}
}
void read_write_pty(int pty, int sockfd)
{
char buffer[MAX_BUFSIZE];
int ret;
// pthread_t thread_t;
// pthread_attr_t attr;
// thread_arg arg;
// arg.pty = pty;
// arg.sockfd = sockfd;
//
// if ((ret = pthread_create(&thread_t, &attr, thread_recv_add_write_pyt,
// (void*) &arg)))
// {
// perror("thread create recieve message and write to pty err:\n");
// }
pid_t pid;
if ((pid = fork()) < 0)
{
perror("");
exit(1);
}
else if (pid == 0)
{
while (1)
{
memset(buffer, 0, MAX_BUFSIZE);
ret = recv(sockfd, buffer, MAX_BUFSIZE - 1, 0);
if (ret < 0)
{
continue;
}
//printf("%s", buffer);
write(pty, buffer, strlen(buffer));
}
}
memset(buffer, 0, MAX_BUFSIZE);
while (ret = read(pty, buffer, MAX_BUFSIZE - 1))
{
buffer[ret - 1] = 0; //read是读不到字符串结束符的，需要自己添加，否则printf会出错
if (ret <= 0)
{
break;
}
fflush(stdout);//这步很重要，std中经常有数据滞留在存储区中需要此函数刷新
printf("%s", buffer);//打印出结果
send(sockfd, buffer, strlen(buffer), 0);
memset(buffer, 0, MAX_BUFSIZE);
}
return;
}
int main(int argc, char **argv)
{
struct sockaddr_in addr;
int sock_fd, addrlen;
/* 获得程序工作的参数，如 IP 、端口、监听数、网页根目录、目录存放位置等 */
getoption(argc, argv);
if (!host)
{
addrlen = strlen(DEFAULTIP);
AllocateMemory(&host, addrlen, DEFAULTIP);
}
if (!port)
{
addrlen = strlen(DEFAULTPORT);
AllocateMemory(&port, addrlen, DEFAULTPORT);
}
if (!back)
{
addrlen = strlen(DEFAULTBACK);
AllocateMemory(&back, addrlen, DEFAULTBACK);
}
if (!dirroot)
{
addrlen = strlen(DEFAULTDIR);
AllocateMemory(&dirroot, addrlen, DEFAULTDIR);
}
if (!logdir)
{
addrlen = strlen(DEFAULTLOG);
AllocateMemory(&logdir, addrlen, DEFAULTLOG);
}
/* fork() 两次处于后台工作模式下 */
if (daemon_y_n)
{
if (fork())
exit(0);
if (fork())
exit(0);
close(0), close(1), close(2);
logfp = fopen(logdir, "a+");
if (!logfp)
exit(0);
}
/* 处理子进程退出以免产生僵尸进程 */
signal(SIGCHLD, SIG_IGN);
/* 创建 socket */
if ((sock_fd = socket(PF_INET, SOCK_STREAM, 0)) < 0)
{
if (!daemon_y_n)
{
prterrmsg("socket()");
}
else
{
wrterrmsg("socket()");
}
}
/* 设置端口快速重用 */
addrlen = 1;
addr.sin_family = AF_INET;
addr.sin_port = htons(atoi(port));
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addrlen = sizeof(struct sockaddr_in);
setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, &addrlen, sizeof(addrlen));
/* 绑定地址、端口等信息 */
if (bind(sock_fd, (struct sockaddr *) &addr, addrlen) < 0)
{
if (!daemon_y_n)
{
prterrmsg("bind()");
}
else
{
wrterrmsg("bind()");
}
}
/* 开启临听 */
if (listen(sock_fd, atoi(back)) < 0)
{
if (!daemon_y_n)
{
prterrmsg("listen()");
}
else
{
wrterrmsg("listen()");
}
}
printf("host=%s port=%s back=%s dirroot=%s logdir=%s %s是后台工作模式(进程ID：%d)\n",
host, port, back, dirroot, logdir, daemon_y_n ? "" : "不", getpid());
while (1)
{
int new_fd;
addrlen = sizeof(struct sockaddr_in);
/* 接受新连接请求 */
new_fd = accept(sock_fd, (struct sockaddr *) &addr, &addrlen);
if (new_fd < 0)
{
if (!daemon_y_n)
{
prterrmsg("accept()");
}
else
{
wrterrmsg("accept()");
}
break;
}
bzero(buffer, MAXBUF + 1);
sprintf(buffer, "连接来自于: %s:%d\n", inet_ntoa(addr.sin_addr), ntohs(
addr.sin_port));
if (!daemon_y_n)
{
prtinfomsg(buffer);
}
else
{
wrtinfomsg(buffer);
}
/* 产生一个子进程去处理请求，当前进程继续等待新的连接到来 */
if (!fork())
{
int ret, ptrfdm;
char slave_name[PTY_NAME_SIZE];
struct termios slave_termiors;
struct winsize slave_winsize;
pid_t ppid;
ret = -1;
ptrfdm = -1;
memset(slave_name, 0, PTY_NAME_SIZE);
ppid = -1;
ret = pty_fork(&ptrfdm, slave_name, PTY_NAME_SIZE, &slave_termiors,
&slave_winsize, &ppid);
if (ret < 0)
{
printf("pty_fork err ! ret = %d", ret);
return -1;
}
if (ppid < 0)
{
printf("pty_fork err !");
return -1;
}
else if (ppid == 0)
{
execl("/bin/bash", "bash", NULL);
}
else
{
read_write_pty(ptrfdm, new_fd);
}
}
close(new_fd);
}
close(sock_fd);
return 0;
}

推荐文章：

Linux伪终端 telnet源码

Linux伪终端 telnet源码

最新Linux教程教程

Linux头条

Linux伪终端 telnet源码

Linux伪终端 telnet源码

相关内容

最新Linux教程教程

Linux头条