// sec, usec = rtctime.get ()
static int rtctime_get (lua_State *L)
{
struct rtc_timeval tv;
rtctime_gettimeofday (&tv);
lua_pushnumber (L, tv.tv_sec);
lua_pushnumber (L, tv.tv_usec);
return 2;
}
static void sntp_dosend (lua_State *L)
{
if (state->attempts == 0)
{
os_timer_disarm (&state->timer);
os_timer_setfn (&state->timer, on_timeout, NULL);
os_timer_arm (&state->timer, 1000, 1);
}
++state->attempts;
sntp_dbg("sntp: attempt %d\n", state->attempts);
struct pbuf *p = pbuf_alloc (PBUF_TRANSPORT, sizeof (ntp_frame_t), PBUF_RAM);
if (!p)
handle_error (L, NTP_MEM_ERR);
ntp_frame_t req;
os_memset (&req, 0, sizeof (req));
req.ver = 4;
req.mode = 3; // client
#ifdef LUA_USE_MODULES_RTCTIME
struct rtc_timeval tv;
rtctime_gettimeofday (&tv);
req.xmit.sec = htonl (tv.tv_sec);
req.xmit.frac = htonl (tv.tv_usec);
#else
req.xmit.frac = htonl (system_get_time ());
#endif
state->cookie = req.xmit;
os_memcpy (p->payload, &req, sizeof (req));
int ret = udp_sendto (state->pcb, p, &server, NTP_PORT);
sntp_dbg("sntp: send: %d\n", ret);
pbuf_free (p);
if (ret != ERR_OK)
handle_error (L, NTP_SEND_ERR);
}
static void on_recv (void *arg, struct udp_pcb *pcb, struct pbuf *p, struct ip_addr *addr, uint16_t port)
{
(void)port;
sntp_dbg("sntp: on_recv\n");
lua_State *L = lua_getstate();
if (!state || state->pcb != pcb)
{
// "impossible", but don't leak if it did happen somehow...
udp_remove (pcb);
pbuf_free (p);
return;
}
if (!p)
return;
if (p->len < sizeof (ntp_frame_t))
{
pbuf_free (p);
return; // not an ntp frame, ignore
}
// make sure we have an aligned copy to work from
ntp_frame_t ntp;
os_memcpy (&ntp, p->payload, sizeof (ntp));
pbuf_free (p);
sntp_dbg("sntp: transmit timestamp: %u, %u\n", ntp.xmit.sec, ntp.xmit.frac);
// sanity checks before we touch our clocks
ip_addr_t anycast;
NTP_ANYCAST_ADDR(&anycast);
if (server.addr != anycast.addr && server.addr != addr->addr)
return; // unknown sender, ignore
if (ntp.origin.sec != state->cookie.sec ||
ntp.origin.frac != state->cookie.frac)
return; // unsolicited message, ignore
if (ntp.LI == 3)
return; // server clock not synchronized (why did it even respond?!)
server.addr = addr->addr;
ntp.origin.sec = ntohl (ntp.origin.sec);
ntp.origin.frac = ntohl (ntp.origin.frac);
ntp.recv.sec = ntohl (ntp.recv.sec);
ntp.recv.frac = ntohl (ntp.recv.frac);
ntp.xmit.sec = ntohl (ntp.xmit.sec);
ntp.xmit.frac = ntohl (ntp.xmit.frac);
const uint32_t UINT32_MAXI = (uint32_t)-1;
const uint64_t MICROSECONDS = 1000000ull;
const uint32_t NTP_TO_UNIX_EPOCH = 2208988800ul;
bool have_cb = (state->sync_cb_ref != LUA_NOREF);
// if we have rtctime, do higher resolution delta calc, else just use
// the transmit timestamp
#ifdef LUA_USE_MODULES_RTCTIME
struct rtc_timeval tv;
rtctime_gettimeofday (&tv);
ntp_timestamp_t dest;
dest.sec = tv.tv_sec;
dest.frac = (MICROSECONDS * tv.tv_usec) / UINT32_MAXI;
// Compensation as per RFC2030
int64_t delta_s = (((int64_t)ntp.recv.sec - ntp.origin.sec) +
((int64_t)ntp.xmit.sec - dest.sec)) / 2;
int64_t delta_f = (((int64_t)ntp.recv.frac - ntp.origin.frac) +
((int64_t)ntp.xmit.frac - dest.frac)) / 2;
dest.sec += delta_s;
if (delta_f + dest.frac < 0)
{
delta_f += UINT32_MAXI;
--dest.sec;
}
else if (delta_f + dest.frac > UINT32_MAXI)
{
delta_f -= UINT32_MAXI;
++dest.sec;
}
dest.frac += delta_f;
tv.tv_sec = dest.sec - NTP_TO_UNIX_EPOCH;
tv.tv_usec = (MICROSECONDS * dest.frac) / UINT32_MAXI;
rtctime_settimeofday (&tv);
if (have_cb)
{
lua_rawgeti (L, LUA_REGISTRYINDEX, state->sync_cb_ref);
lua_pushnumber (L, tv.tv_sec);
lua_pushnumber (L, tv.tv_usec);
}
#else
if (have_cb)
{
lua_rawgeti (L, LUA_REGISTRYINDEX, state->sync_cb_ref);
lua_pushnumber (L, ntp.xmit.sec - NTP_TO_UNIX_EPOCH);
lua_pushnumber (L, (MICROSECONDS * ntp.xmit.frac) / UINT32_MAXI);
}
#endif
cleanup (L);
if (have_cb)
{
lua_pushstring (L, ipaddr_ntoa (&server));
lua_call (L, 3, 0);
}
}