2
0
mirror of https://gitlab.isc.org/isc-projects/kea synced 2025-08-30 13:37:55 +00:00

[#1307] kea-dhcp4 now enforces parked-packet-limit

src/bin/dhcp4/dhcp4_srv.cc
    Dhcpv4Srv::processDhcp4Query() - now drops packet and response
    if parking lot size reaches parked-packet-limit

src/bin/dhcp4/dhcp4_messages.*
    DHCP4_HOOK_LEASES4_PARKING_LOT_FULL - new message
This commit is contained in:
Thomas Markwalder 2021-09-03 08:26:38 -04:00
parent f914dd9c96
commit f14163b51e
4 changed files with 36 additions and 0 deletions

View File

@ -75,6 +75,7 @@ extern const isc::log::MessageID DHCP4_HOOK_DECLINE_SKIP = "DHCP4_HOOK_DECLINE_S
extern const isc::log::MessageID DHCP4_HOOK_LEASE4_RELEASE_SKIP = "DHCP4_HOOK_LEASE4_RELEASE_SKIP";
extern const isc::log::MessageID DHCP4_HOOK_LEASES4_COMMITTED_DROP = "DHCP4_HOOK_LEASES4_COMMITTED_DROP";
extern const isc::log::MessageID DHCP4_HOOK_LEASES4_COMMITTED_PARK = "DHCP4_HOOK_LEASES4_COMMITTED_PARK";
extern const isc::log::MessageID DHCP4_HOOK_LEASES4_PARKING_LOT_FULL = "DHCP4_HOOK_LEASES4_PARKING_LOT_FULL";
extern const isc::log::MessageID DHCP4_HOOK_PACKET_RCVD_SKIP = "DHCP4_HOOK_PACKET_RCVD_SKIP";
extern const isc::log::MessageID DHCP4_HOOK_PACKET_SEND_DROP = "DHCP4_HOOK_PACKET_SEND_DROP";
extern const isc::log::MessageID DHCP4_HOOK_PACKET_SEND_SKIP = "DHCP4_HOOK_PACKET_SEND_SKIP";
@ -230,6 +231,7 @@ const char* values[] = {
"DHCP4_HOOK_LEASE4_RELEASE_SKIP", "%1: lease was not released because a callout set the next step to SKIP",
"DHCP4_HOOK_LEASES4_COMMITTED_DROP", "%1: packet is dropped, because a callout set the next step to DROP",
"DHCP4_HOOK_LEASES4_COMMITTED_PARK", "%1: packet is parked, because a callout set the next step to PARK",
"DHCP4_HOOK_LEASES4_PARKING_LOT_FULL", "The parked-packet-limit %1, has been reached, dropping query: %2",
"DHCP4_HOOK_PACKET_RCVD_SKIP", "%1: packet is dropped, because a callout set the next step to SKIP",
"DHCP4_HOOK_PACKET_SEND_DROP", "%1: prepared DHCPv4 response was not sent because a callout set the next ste to DROP",
"DHCP4_HOOK_PACKET_SEND_SKIP", "%1: prepared response is not sent, because a callout set the next stp to SKIP",

View File

@ -76,6 +76,7 @@ extern const isc::log::MessageID DHCP4_HOOK_DECLINE_SKIP;
extern const isc::log::MessageID DHCP4_HOOK_LEASE4_RELEASE_SKIP;
extern const isc::log::MessageID DHCP4_HOOK_LEASES4_COMMITTED_DROP;
extern const isc::log::MessageID DHCP4_HOOK_LEASES4_COMMITTED_PARK;
extern const isc::log::MessageID DHCP4_HOOK_LEASES4_PARKING_LOT_FULL;
extern const isc::log::MessageID DHCP4_HOOK_PACKET_RCVD_SKIP;
extern const isc::log::MessageID DHCP4_HOOK_PACKET_SEND_DROP;
extern const isc::log::MessageID DHCP4_HOOK_PACKET_SEND_SKIP;

View File

@ -391,6 +391,14 @@ hook point sets the next step to DROP.
This debug message is printed when a callout installed on the leases4_committed
hook point sets the next step to PARK.
% DHCP4_HOOK_LEASES4_PARKING_LOT_FULL The parked-packet-limit %1, has been reached, dropping query: %2
This debug message occurs when the parking lot used to hold client queries
while hook library work for them completes has reached or exceeded the
limit set by the parked-packet-limit global parameter. This can occur when
kea-dhcp4 is using hook libraries (e.g. HA) that implement the
"leases4-committed" callout and client queries are arriving faster than
those callouts can fulfill them.
% DHCP4_HOOK_PACKET_RCVD_SKIP %1: packet is dropped, because a callout set the next step to SKIP
This debug message is printed when a callout installed on the pkt4_receive
hook point sets the next step to SKIP. For this particular hook point, the

View File

@ -1356,6 +1356,31 @@ Dhcpv4Srv::processDhcp4Query(Pkt4Ptr& query, Pkt4Ptr& rsp,
callout_handle->setArgument("deleted_leases4", deleted_leases);
if (allow_packet_park) {
// Get the parking limit. Parsing should ensure the value is present.
uint32_t parked_packet_limit = 0;
data::ConstElementPtr ppl = CfgMgr::instance().
getCurrentCfg()->getConfiguredGlobal("parked-packet-limit");
if (ppl) {
parked_packet_limit = ppl->intValue();
}
if (parked_packet_limit) {
const auto& parking_lot = ServerHooks::getServerHooks().
getParkingLotPtr("leases4_committed");
if (parking_lot && (parking_lot->size() >= parked_packet_limit)) {
// We can't park it so we're going to throw it on the floor.
LOG_DEBUG(packet4_logger, DBGLVL_PKT_HANDLING,
DHCP4_HOOK_LEASES4_PARKING_LOT_FULL)
.arg(parked_packet_limit)
.arg(query->getLabel());
isc::stats::StatsMgr::instance().addValue("pkt4-receive-drop",
static_cast<int64_t>(1));
rsp.reset();
return;
}
}
// We proactively park the packet. We'll unpark it without invoking
// the callback (i.e. drop) unless the callout status is set to
// NEXT_STEP_PARK. Otherwise the callback we bind here will be