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342 | // Copyright (C) 2020-2023 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#include <config.h>
#include <dhcp4/client_handler.h>
#include <dhcp4/dhcp4_log.h>
#include <exceptions/exceptions.h>
#include <stats/stats_mgr.h>
#include <util/multi_threading_mgr.h>
using namespace std;
using namespace isc::util;
using namespace isc::log;
namespace isc {
namespace dhcp {
ClientHandler::Client::Client(Pkt4Ptr query, ClientIdPtr client_id,
HWAddrPtr hwaddr)
: query_(query), htype_(HTYPE_ETHER), thread_(this_thread::get_id()) {
// Sanity checks.
if (!query) {
isc_throw(InvalidParameter, "null query in ClientHandler");
}
if (!client_id && (!hwaddr || hwaddr->hwaddr_.empty())) {
isc_throw(InvalidParameter,
"null client-id and hwaddr in ClientHandler");
}
if (client_id) {
client_id_ = client_id->getClientId();
}
if (hwaddr && !hwaddr->hwaddr_.empty()) {
htype_ = hwaddr->htype_;
hwaddr_ = hwaddr->hwaddr_;
}
}
mutex ClientHandler::mutex_;
ClientHandler::ClientByIdContainer ClientHandler::clients_client_id_;
ClientHandler::ClientByHWAddrContainer ClientHandler::clients_hwaddr_;
ClientHandler::ClientPtr
ClientHandler::lookup(const ClientIdPtr& client_id) {
// Sanity check.
if (!client_id) {
isc_throw(InvalidParameter, "null client-id in ClientHandler::lookup");
}
auto it = clients_client_id_.find(client_id->getClientId());
if (it == clients_client_id_.end()) {
return (ClientPtr());
}
return (*it);
}
ClientHandler::ClientPtr
ClientHandler::lookup(const HWAddrPtr& hwaddr) {
// Sanity checks.
if (!hwaddr) {
isc_throw(InvalidParameter, "null hwaddr in ClientHandler::lookup");
}
if (hwaddr->hwaddr_.empty()) {
isc_throw(InvalidParameter, "empty hwaddr in ClientHandler::lookup");
}
auto key = boost::make_tuple(hwaddr->htype_, hwaddr->hwaddr_);
auto it = clients_hwaddr_.find(key);
if (it == clients_hwaddr_.end()) {
return (ClientPtr());
}
return (*it);
}
void
ClientHandler::addById(const ClientPtr& client) {
// Sanity check.
if (!client) {
isc_throw(InvalidParameter, "null client in ClientHandler::addById");
}
// Assume insert will never fail so not checking its result.
clients_client_id_.insert(client);
}
void
ClientHandler::addByHWAddr(const ClientPtr& client) {
// Sanity check.
if (!client) {
isc_throw(InvalidParameter,
"null client in ClientHandler::addByHWAddr");
}
// Assume insert will never fail so not checking its result.
clients_hwaddr_.insert(client);
}
void
ClientHandler::del(const ClientIdPtr& client_id) {
// Sanity check.
if (!client_id) {
isc_throw(InvalidParameter, "null duid in ClientHandler::del");
}
// Assume erase will never fail so not checking its result.
clients_client_id_.erase(client_id->getClientId());
}
void
ClientHandler::del(const HWAddrPtr& hwaddr) {
// Sanity checks.
if (!hwaddr) {
isc_throw(InvalidParameter, "null hwaddr in ClientHandler::del");
}
if (hwaddr->hwaddr_.empty()) {
isc_throw(InvalidParameter, "empty hwaddr in ClientHandler::del");
}
auto key = boost::make_tuple(hwaddr->htype_, hwaddr->hwaddr_);
// Assume erase will never fail so not checking its result.
auto it = clients_hwaddr_.find(key);
if (it == clients_hwaddr_.end()) {
// Should not happen.
return;
}
clients_hwaddr_.erase(it);
}
ClientHandler::ClientHandler()
: client_(), locked_client_id_(), locked_hwaddr_() {
}
ClientHandler::~ClientHandler() {
bool unlocked = false;
lock_guard<mutex> lk(mutex_);
if (locked_client_id_) {
unlocked = true;
unLockById();
}
if (locked_hwaddr_) {
unlocked = true;
unLockByHWAddr();
}
if (!unlocked || !client_ || !client_->cont_) {
return;
}
// Try to process next query. As the caller holds the mutex of
// the handler class the continuation will be resumed after.
MultiThreadingMgr& mt_mgr = MultiThreadingMgr::instance();
if (mt_mgr.getMode()) {
if (!mt_mgr.getThreadPool().addFront(client_->cont_)) {
LOG_DEBUG(dhcp4_logger, DBG_DHCP4_BASIC, DHCP4_PACKET_QUEUE_FULL);
}
}
}
bool
ClientHandler::tryLock(Pkt4Ptr query, ContinuationPtr cont) {
// Sanity checks.
if (!query) {
isc_throw(InvalidParameter, "null query in ClientHandler::tryLock");
}
if (locked_client_id_) {
isc_throw(Unexpected,
"already handling client-id in ClientHandler::tryLock");
}
if (locked_hwaddr_) {
isc_throw(Unexpected,
"already handling hwaddr in ClientHandler::tryLock");
}
// Get identifiers.
OptionPtr opt_client_id = query->getOption(DHO_DHCP_CLIENT_IDENTIFIER);
ClientIdPtr client_id;
if (opt_client_id) {
client_id.reset(new ClientId(opt_client_id->getData()));
}
HWAddrPtr hwaddr = query->getHWAddr();
if (hwaddr && hwaddr->hwaddr_.empty()) {
hwaddr.reset();
}
if (!client_id && !hwaddr) {
// Can't do something useful: cross fingers.
return (true);
}
ClientPtr holder_id;
ClientPtr holder_hw;
Pkt4Ptr next_query_id;
Pkt4Ptr next_query_hw;
client_.reset(new Client(query, client_id, hwaddr));
{
lock_guard<mutex> lk(mutex_);
// Try first duid.
if (client_id) {
// Try to acquire the by-client-id lock and return the holder
// when it failed.
holder_id = lookup(client_id);
if (!holder_id) {
locked_client_id_ = client_id;
lockById();
} else if (cont) {
next_query_id = holder_id->next_query_;
holder_id->next_query_ = query;
holder_id->cont_ = cont;
}
}
if (!holder_id) {
if (!hwaddr) {
return (true);
}
// Try to acquire the by-hw-addr lock and return the holder
// when it failed.
holder_hw = lookup(hwaddr);
if (!holder_hw) {
locked_hwaddr_ = hwaddr;
lockByHWAddr();
return (true);
} else if (cont) {
next_query_hw = holder_hw->next_query_;
holder_hw->next_query_ = query;
holder_hw->cont_ = cont;
}
}
}
if (holder_id) {
// This query is a by-id duplicate so put the continuation.
if (cont) {
if (next_query_id) {
// Logging a warning as it is supposed to be a rare event
// with well behaving clients...
LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0011)
.arg(next_query_id->getHWAddrLabel())
.arg(next_query_id->toText())
.arg(this_thread::get_id())
.arg(holder_id->query_->getHWAddrLabel())
.arg(holder_id->query_->toText())
.arg(holder_id->thread_);
stats::StatsMgr::instance().addValue("pkt4-receive-drop",
static_cast<int64_t>(1));
}
} else {
// Logging a warning as it is supposed to be a rare event
// with well behaving clients...
LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0011)
.arg(query->getHWAddrLabel())
.arg(query->toText())
.arg(this_thread::get_id())
.arg(holder_id->query_->getHWAddrLabel())
.arg(holder_id->query_->toText())
.arg(holder_id->thread_);
stats::StatsMgr::instance().addValue("pkt4-receive-drop",
static_cast<int64_t>(1));
}
} else {
// This query is a by-hw duplicate so put the continuation.
if (cont) {
if (next_query_hw) {
// Logging a warning as it is supposed to be a rare event
// with well behaving clients...
LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0012)
.arg(next_query_hw->getHWAddrLabel())
.arg(next_query_hw->toText())
.arg(this_thread::get_id())
.arg(holder_hw->query_->getHWAddrLabel())
.arg(holder_hw->query_->toText())
.arg(holder_hw->thread_);
stats::StatsMgr::instance().addValue("pkt4-receive-drop",
static_cast<int64_t>(1));
}
} else {
// Logging a warning as it is supposed to be a rare event
// with well behaving clients...
LOG_DEBUG(bad_packet4_logger, DBGLVL_PKT_HANDLING, DHCP4_PACKET_DROP_0012)
.arg(query->getHWAddrLabel())
.arg(query->toText())
.arg(this_thread::get_id())
.arg(holder_hw->query_->getHWAddrLabel())
.arg(holder_hw->query_->toText())
.arg(holder_hw->thread_);
stats::StatsMgr::instance().addValue("pkt4-receive-drop",
static_cast<int64_t>(1));
}
}
return (false);
}
void
ClientHandler::lockById() {
// Sanity check.
if (!locked_client_id_) {
isc_throw(Unexpected, "nothing to lock in ClientHandler::lockById");
}
addById(client_);
}
void
ClientHandler::lockByHWAddr() {
// Sanity check.
if (!locked_hwaddr_) {
isc_throw(Unexpected,
"nothing to lock in ClientHandler::lockByHWAddr");
}
addByHWAddr(client_);
}
void
ClientHandler::unLockById() {
// Sanity check.
if (!locked_client_id_) {
isc_throw(Unexpected,
"nothing to unlock in ClientHandler::unLockById");
}
del(locked_client_id_);
locked_client_id_.reset();
}
void
ClientHandler::unLockByHWAddr() {
// Sanity check.
if (!locked_hwaddr_) {
isc_throw(Unexpected,
"nothing to unlock in ClientHandler::unLockByHWAddr");
}
del(locked_hwaddr_);
locked_hwaddr_.reset();
}
} // namespace dhcp
} // namespace isc
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