//分析ntp调用过程//刘术河 2016.08.17
Ntp-keygen.c (util):main(Ntpd.c (ntpd):main(Ntpd.c (ntpd):main(Ntpdate.c (ntpdate):main(Ntpdc.c (ntpdc):main(Ntpq.c (ntpq):main(Ntptime.c (util):main(Sntp.c (sntp):main (Tickadj.c (util):main(Tickadj.c (util):main(
//开发板上电只调用ntpd\ntp-4.2.6p5\ntpd\Ntpd.cmain( ntpdmain(argc, argv); get_systime(&now); ntp_srandom((int)(now.l_i * now.l_uf)); init_auth(); init_util(); init_restrict(); init_mon(); init_timer(); init_lib(); init_request(); init_control(); init_peer(); #ifdef REFCLOCK init_refclock(); { for (i = 0; i < (int)num_refclock_conf; i++) if (refclock_conf[i]->clock_init != noentry) (refclock_conf[i]->clock_init)(); //这个refclock_conf----是一个结构体，并调用结构体的clock_init，但是refclock_nmea没有init所以跳过 struct refclock * const refclock_conf[] = { ................ &refclock_nmea, /* 20 REFCLK_GPS_NMEA */ ................ }
} #endif set_process_priority(); init_proto(); /* Call at high priority */ init_io(); init_loopfilter(); mon_start(MON_ON); /* monitor on by default now */ /* turn off in config if unwanted */
/* * Get the configuration. This is done in a separate module * since this will definitely be different for the gizmo board. */ getconfig(argc, argv); report_event(EVNT_SYSRESTART, NULL, NULL); loop_config(LOOP_DRIFTCOMP, old_drift);//ntpd\Ntp_peer.c1.peer_config return(newpeer(srcadr, dstadr, hmode, version, minpoll, maxpoll, newpeer( if (!refclock_newpeer(peer)) { refclock_newpeer refclock_conf[clktype]->clock_start == noentry) {//\ntp-4.2.6p5\ntpd\Ntp_proto.c2.receive if ((peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr, newpeer( if (!refclock_newpeer(peer)) { refclock_newpeer refclock_conf[clktype]->clock_start == noentry) {//先分析peer_config //ntpd\Ntp_request.c proc = ntp_codes; inpkt->request == REQ_CONFIG && req_ack(srcadr, inter, inpkt, INFO_ERR_FMT); static struct req_proc ntp_codes[] = { sizeof(struct conf_peer), do_conf }, } do_conf if (peer_config(&peeraddr, (struct interface *)0, //ntpd\Ntp_config.c #ifndef SIM //如果sim没有定义，才执行，所以Ntp_config这条分之不执行 config_ntpd(ptree); #else config_ntpd config_peers(ptree); config_peers peer_config(&peeraddr,
//再分析receiveNtpsim.c (ntpd): rbuf.receiver = receive; /* Function to call to process the packet */Ntptimeset.c (ntpdate): receive(rbuf);Ntp_io.c (ntpd): rb->receiver = receive;Ntp_iocompletionport.c (ports\winnt\ntpd): buff->receiver = receive;
0.先看Ntpsim和Ntp_io，最终调用到这里#ifdef SIM cc = simulate_server(dest, src, pkt);#else
1.先看Ntptimeset.cmain ntptimesetmain receive(rbuf);但是这个程序，我们不调用它，所以现在只剩下Ntp_iocompletionport.c 2.分析Ntp_iocompletionport.c //这个SYS_WINNT没有定义，所以都不执行#ifdef SYS_WINNT init_io_completion_port();#endif /* SYS_WINNT */
thread = (HANDLE)_beginthreadex( NULL, 0, iocompletionthread, NULL, CREATE_SUSPENDED, &tid); ResumeThread(thread); CloseHandle(thread);
iocompletionthread case SOCK_RECV: OnSocketRecv(Key, lpo, BytesTransferred, errstatus); buff->receiver = receive;
//到这里主线清楚 //ntp-4.2.6p5\ntpd\Ntp_request.c req_ack //ntp-4.2.6p5\ntpd\Ntp_io.c sendpkt(srcadr, inter, -1, (struct pkt *)&rpkt, RESP_HEADER_SIZE); #ifdef SIM cc = simulate_server(dest, src, pkt); #else
转载于:https://www.cnblogs.com/liushuhe1990/p/9609013.html
