ntp.h

linux下的internet time 时间同步代码

/* ntp.h

 * NTP definitions for the sntpdate
 *
 * Copyright 2003 Norimasa Matsumoto <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 */

#ifndef NTP_H
#define NTP_H

#define NTP_SERV         "ntp"
#define NTP_VN           4
#define NTP_MODE_CLIENT  3
#define NTP_MODE_SERVER  4
#define NTP_TIMEOUT_SEC  5
#define NTP_TIMEOUT_USEC 0

#define ntp_li(x)   ( (x>>6) & 3 )
#define ntp_vn(x)   ( (x>>3) & 7 )
#define ntp_mode(x) (  x     & 7 )

#define min( a, b ) ( (a>b)?(b):(a) )

typedef struct {
    unsigned int sec;
    unsigned int fsec;
} ntp_time;

struct pkt {
    unsigned char li_vn_mode;      /* leap indicator, version and mode */
    unsigned char stratum;         /* peer stratum */
    unsigned char ppoll;           /* peer poll interval */
    char          precision;       /* peer clock precision */
    unsigned int  rootdelay;       /* distance to primary clock */
    unsigned int  rootdispersion;  /* clock dispersion */
    unsigned int  refid;           /* reference clock ID */
    ntp_time      reftime;         /* time peer clock was last updated */
    ntp_time      org;             /* originate time stamp */
    ntp_time      rec;             /* receive time stamp */
    ntp_time      xmt;             /* transmit time stamp */
};

#endif /* NTP_H */