static int ntpsync_main(int argc, char **argv)
{
char *servers, *t, *p;
char *addr[10];
char *ips;
char *nvkiss;
int count;
int i;
struct hostent *he;
struct in_addr ia;
int retries;
int nu;
char s[512];
time_t tt;
struct tm *tms;
enum { USER, INIT, CRON } mode;
nu = nvram_get_int("ntp_updates");
mode = USER;
if (argc == 2) {
if (strcmp(argv[1], "--cron") == 0) { // try for a few minutes
if (nu <= 0) {
eval("cru", "d", "ntpsync");
return 0;
}
mode = CRON;
}
else if (strcmp(argv[1], "--init") == 0) { // try forever, schedule cron job
if (fork() != 0) return 0;
mode = INIT;
}
else {
return 1;
}
}
else if (argc != 1) {
return 1;
}
_dprintf("[ntpsync %ld] start\n", get_uptime());
if ((get_wan_proto() != WP_DISABLED) && (mode != INIT) &&
(!check_wanup()) && (nvram_match("ntp_tdod", "0"))) {
_dprintf("WAN is down, not updating.");
return 1;
}
srand(time(0));
retries = 0;
while (1) {
_dprintf("[ntpsync %ld] while\n", get_uptime());
count = 0;
servers = p = strdup(nvram_safe_get("ntp_server"));
if (!servers) {
printf("Not enough memory\n");
return 1;
}
while ((count < 10) && ((t = strsep(&p, " ")) != NULL)) {
if (*t != 0) addr[count++] = t;
}
if (count == 0) addr[count++] = "pool.ntp.org";
while (count > 0) {
i = (rand() % count);
_dprintf("[ntpsync] i=%d addr=%s\n", i, addr[i]);
if ((he = gethostbyname(addr[i])) != NULL) {
memcpy(&ia, he->h_addr_list[0], sizeof(ia));
ips = inet_ntoa(ia);
_dprintf("ip = %s\n", ips);
nvkiss = nvram_safe_get("ntp_kiss");
if (find_word(nvkiss, ips)) {
_dprintf("kiss: %s\n", ips);
}
else {
switch (ntpc(ia)) {
case 0:
_dprintf("[ntpsync] %ld OK\n", get_uptime());
if (mode == INIT) {
tt = time(0);
if ((nu > 0) && ((tms = localtime(&tt)) != NULL)) {
// add some randomness to make the servers happier / avoid the xx:00 rush
sprintf(s, "%d ", (tms->tm_min + 20 + (rand() % 20)) % 60);
// schedule every nu hours
for (i = 0; i < 24; ++i) {
if ((i % nu) == 0) sprintf(s + strlen(s), "%s%d", i ? "," : "", (i + tms->tm_hour + 1) % 24);
}
strcat(s, " * * * ntpsync --cron");
eval("cru", "a", "ntpsync", s);
}
}
// make sure access restriction is ok
eval("rcheck");
_dprintf("[ntpsync] %ld exit\n", get_uptime());
return 0;
case 2:
while ((nvkiss) && (strlen(nvkiss) > 128)) nvkiss = strchr(nvkiss + 1, ' ');
if (nvkiss) strlcpy(s, nvkiss, sizeof(s));
else s[0] = 0;
add_word(s, ips, sizeof(s));
nvram_set("ntp_kiss", s);
syslog(LOG_WARNING, "Received a kiss of death packet from %s (%s).", addr[i], ips);
break;
}
}
}
addr[i] = addr[--count];
}
free(servers);
if (mode == USER) break;
if ((mode == CRON) && (retries == 5)) break;
if (++retries > 300) retries = 300; // 5m
_dprintf("[ntpsync %ld] sleep=%d\n", get_uptime(), retries);
sleep(retries);
}
_dprintf("[ntpsync] %ld exit\n", get_uptime());
return 1;
}
const char *get_wanip(void)
{
if (!check_wanup()) return "0.0.0.0";
return (*get_wanfaces()).iface[0].ip;
}
