struct ppp_info{
	int unit;			/**/
	int dev_fd;			/**/
	int lcp_fd;			/**/
	int ppp_fd;			/**/
	int remote_id;		/**/
	char	*user;		/* Username for authentication */
	char	*passwd;	/* Password for authentication */
	char *ifname;
	char attach_inter[16];
	unsigned char distance;
	unsigned char weight;
	unsigned char gateway;
	unsigned char dns;
	unsigned char auth;
	unsigned char auth_type;
	unsigned char down_flag;			//避免PPP主动down掉和手动清除冲突
	unsigned int unique;
	unsigned int dns_value;
	unsigned int wins_value;
	char usergrp[MAXNAMELEN];
	struct prefix_ipv4 localaddr;
	unsigned int peer_address;			//tunnip
	int lcp_detect_interval_time;		//for change interval time of lcp echo request
	int lcp_detect_lost_times;			//for change times of no respons lcp echo request
	struct thread * lcp_thread;
	struct thread * ipcp_rthread;
    void *conn;
    void *priv_data;
    int natid;
	int mtu;
	Ppp_if_type iftype;
	int (*manage_auto_down) (char *ifname);
	int (*ipcp_up_cb) (struct ppp_cb_info *cb_info);
	int (*ipcp_down_cb) (struct ppp_cb_info *cb_info);
	int (*lcp_auth) (char *name, char *group, char *password, unsigned char *challenge, int unit, int type);
	int (*check_rqci)(__u32 addr);
};

#define _XOPEN_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <pty.h>
int main()
{
        int fd_m, fd_s;
        int len;
        const char *pts_name;
        char send_buf[64] = "abc\ndefghijk\nlmn";
        char recv_buf[64] = {0};
        fd_m = open("/dev/ptmx", O_RDWR | O_NOCTTY);
        if (fd_m < 0) {
                printf("open /dev/ptmx fail1\n");
                return -1;
        }
        if (grantpt(fd_m) < 0 || unlockpt(fd_m) < 0) {
                printf("grantpt and unlockpt fail\n");
                goto err;
        }
        pts_name = (const char *)ptsname(fd_m);
        fd_s = open(pts_name, O_RDONLY | O_NOCTTY);
        if (fd_s < 0) {
                printf("open /dev/ptmx fail2\n");
                goto err;
        }
        len = write(fd_m, send_buf, strlen(send_buf));
        printf("write len=%d\n", len);
        len = read(fd_s, recv_buf, sizeof(recv_buf));
        printf("read len=%d, recv_buf=[%s]\n", len, recv_buf);
        len = read(fd_s, recv_buf, sizeof(recv_buf));
        printf("read len=%d, recv_buf=[%s]\n", len, recv_buf);
        close(fd_m);
        close(fd_s);
        return 0;
err:
        if (fd_m)
                close(fd_m);
        if (fd_s)
                close(fd_s);
        return -1;
}