ntp: avoid unnecessary source lookups

Avoid searching the hash table of sources when a packet in the client
mode is received. It cannot be a response from our source. Analogously,
avoid source lookups for transmitted packets in the server mode. This
doesn't change anything for packets in symmetric modes, which can be
requests and responses at the same time.

This slightly improves the maximum packet rate handled as a server.
This commit is contained in:
Miroslav Lichvar
2021-12-14 10:04:39 +01:00
parent fcd384523b
commit f2ba20f293
2 changed files with 14 additions and 7 deletions

View File

@@ -1100,8 +1100,10 @@ NSR_ProcessRx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
assert(initialised);
/* Must match IP address AND port number */
if (find_slot2(remote_addr, &slot) == 2) {
/* Avoid unnecessary lookup if the packet cannot be a response from our
source. Otherwise, it must match both IP address and port number. */
if (NTP_LVM_TO_MODE(message->lvm) != MODE_CLIENT &&
find_slot2(remote_addr, &slot) == 2) {
record = get_record(slot);
if (!NCR_ProcessRxKnown(record->data, local_addr, rx_ts, message, length))
@@ -1137,8 +1139,10 @@ NSR_ProcessTx(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
SourceRecord *record;
int slot;
/* Must match IP address AND port number */
if (find_slot2(remote_addr, &slot) == 2) {
/* Avoid unnecessary lookup if the packet cannot be a request to our
source. Otherwise, it must match both IP address and port number. */
if (NTP_LVM_TO_MODE(message->lvm) != MODE_SERVER &&
find_slot2(remote_addr, &slot) == 2) {
record = get_record(slot);
NCR_ProcessTxKnown(record->data, local_addr, tx_ts, message, length);
} else {