faraphel/chrony
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Add client support for Kiss-of-Death RATE

Browse source 
This adds support for RATE code which can be used in reply from NTP
server to reduce client's polling.
This commit is contained in:
Miroslav Lichvar 2009-06-30 17:47:11 +02:00
parent 032d1db883
commit 923c58485f
1 changed files with 27 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

27
ntp_core.c
View file

@ -812,6 +812,10 @@ receive_packet(NTP_Packet *message, struct timeval *now, NCR_Instance inst, int
int valid_data;
int valid_header;
/* Kiss-of-Death packets */
int kod_rate = 0;
int valid_kod;
/* Variables used for doing logging */
static char sync_stats[4] = {'N', '+', '-', '?'};
@ -1018,6 +1022,14 @@ receive_packet(NTP_Packet *message, struct timeval *now, NCR_Instance inst, int
test8 = 1;
}
/* Check for Kiss-of-Death */
if (message->stratum > NTP_MAX_STRATUM && !source_is_synchronized) {
if (!memcmp(&message->reference_id, "RATE", 4))
kod_rate = 1;
}
valid_kod = test1 && test2 && test5;
valid_data = test1 && test2 && test3 && test4 && test4a && test4b;
valid_header = test5 && test6 && test7 && test8;
@ -1052,6 +1064,8 @@ receive_packet(NTP_Packet *message, struct timeval *now, NCR_Instance inst, int
LOG(LOGS_INFO, LOGF_NtpCore, "test5=%d test6=%d test7=%d test8=%d valid_header=%d",
test5, test6, test7, test8, valid_header);
LOG(LOGS_INFO, LOGF_NtpCore, "kod_rate=%d valid_kod=%d", kod_rate, valid_kod);
#endif
if (valid_header) {
@ -1219,6 +1233,19 @@ receive_packet(NTP_Packet *message, struct timeval *now, NCR_Instance inst, int
}
/* Reduce polling if KoD RATE was received */
if (kod_rate && valid_kod) {
if (inst->remote_poll > inst->minpoll) {
inst->minpoll = inst->remote_poll;
if (inst->minpoll > inst->maxpoll)
inst->maxpoll = inst->minpoll;
if (inst->minpoll > inst->local_poll)
inst->local_poll = inst->minpoll;
LOG(LOGS_INFO, LOGF_NtpCore, "Received KoD RATE from %s, minpoll set to %d", UTI_IPToDottedQuad(inst->remote_addr.ip_addr), inst->minpoll);
}
/* Back off for a while */
delay_time += (double) (4 * (1UL << inst->minpoll));
}
if (requeue_transmit) {
/* Get rid of old timeout and start a new one */