DWS/chrony
1
0
Fork 0
mirror of https://gitlab.com/chrony/chrony.git synced 2025-12-03 16:35:06 -05:00
Code Issues Packages Projects Releases Wiki Activity

ntp: avoid unneccessary replacements on refresh command

Browse Source 
When the refresh command is issued, instead of trying to replace all
NTP sources as if they were unreachable or falsetickers, keep using the
current address if it is still returned by the resolver for the name.
This avoids unnecessary loss of measurements and switching to
potentially unreachable addresses.
This commit is contained in:
Miroslav Lichvar
2023-05-15 16:26:21 +02:00
parent 6a6161dc0f
commit b2dac47c82
3 changed files with 62 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
ntp_sources.c
View File

@@ -96,6 +96,9 @@ struct UnresolvedSource {
char *name;
/* Flag indicating addresses should be used in a random order */
int random_order;
/* Flag indicating current address should be replaced only if it is
no longer returned by the resolver */
int refreshment;
/* Next unresolved source in the list */
struct UnresolvedSource *next;
};
@@ -517,6 +520,19 @@ process_resolved_name(struct UnresolvedSource *us, IPAddr *ip_addrs, int n_addrs
unsigned short first = 0;
int i, j;
/* Keep using the current address if it is being refreshed and it is
still included in the resolved addresses */
if (us->refreshment) {
assert(us->pool_id == INVALID_POOL);
for (i = 0; i < n_addrs; i++) {
if (UTI_CompareIPs(&us->address.ip_addr, &ip_addrs[i], NULL) == 0) {
DEBUG_LOG("%s still fresh", UTI_IPToString(&us->address.ip_addr));
return;
}
}
}
if (us->random_order)
UTI_GetRandomBytes(&first, sizeof (first));
@@ -773,6 +789,7 @@ NSR_AddSourceByName(char *name, int port, int pool, NTP_Source_Type type,
us = MallocNew(struct UnresolvedSource);
us->name = Strdup(name);
us->random_order = 0;
us->refreshment = 0;
remote_addr.ip_addr.family = IPADDR_ID;
remote_addr.ip_addr.addr.id = ++last_address_id;
@@ -962,7 +979,7 @@ NSR_RemoveAllSources(void)
/* ================================================== */
static void
resolve_source_replacement(SourceRecord *record)
resolve_source_replacement(SourceRecord *record, int refreshment)
{
struct UnresolvedSource *us;
@@ -976,6 +993,7 @@ resolve_source_replacement(SourceRecord *record)
stuck to a pair of addresses if the order doesn't change, or a group of
IPv4/IPv6 addresses if the resolver prefers inaccessible IP family */
us->random_order = record->tentative;
us->refreshment = refreshment;
us->pool_id = INVALID_POOL;
us->address = *record->remote_addr;
@@ -1015,7 +1033,7 @@ NSR_HandleBadSource(IPAddr *address)
}
last_replacement = now;
resolve_source_replacement(record);
resolve_source_replacement(record, 0);
}
/* ================================================== */
@@ -1031,7 +1049,7 @@ NSR_RefreshAddresses(void)
if (!record->remote_addr)
continue;
resolve_source_replacement(record);
resolve_source_replacement(record, 1);
}
}