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148 | // Copyright (C) 2013-2024 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/.
/// @file subnet_select_co.cc Defines the subnet4_select and subnet6_select callout functions.
#include <config.h>
#include <hooks/hooks.h>
#include <dhcp/pkt4.h>
#include <dhcp/dhcp6.h>
#include <dhcp/pkt6.h>
#include <dhcpsrv/subnet.h>
#include <user_chk.h><--- Include file: not found. Please note: Cppcheck does not need standard library headers to get proper results.
#include <user_chk_log.h><--- Include file: not found. Please note: Cppcheck does not need standard library headers to get proper results.
using namespace isc::dhcp;
using namespace isc::hooks;
using namespace user_chk;
using namespace std;
// Functions accessed by the hooks framework use C linkage to avoid the name
// mangling that accompanies use of the C++ compiler as well as to avoid
// issues related to namespaces.
extern "C" {
/// @brief This callout is called at the "subnet4_select" hook.
///
/// This function alters the selected subnet based upon whether or not the
/// requesting DHCP client is a "registered user". It fetches a pointer to
/// the registered user from the callout context. This value is presumed to
/// have been set upstream. If it is non-null that it points to the client's
/// user entry in the UserRegistry. If it is null, the client is not
/// registered.
///
/// If the client is registered, then replace the selected subnet with the
/// restricted access subnet. By convention, it is assumed that last subnet in
/// the list of available subnets is the restricted access subnet.
///
/// @param handle CalloutHandle which provides access to context.
///
/// @return 0 upon success, non-zero otherwise.
int subnet4_select(CalloutHandle& handle) {
CalloutHandle::CalloutNextStep status = handle.getStatus();
if (status == CalloutHandle::NEXT_STEP_DROP ||
status == CalloutHandle::NEXT_STEP_SKIP) {
return (0);
}
if (!user_registry) {
LOG_ERROR(user_chk_logger, USER_CHK_SUBNET4_SELECT_REGISTRY_NULL);
return (1);
}
try {
// Get subnet collection. If it's empty just bail nothing to do.
const isc::dhcp::Subnet4Collection *subnets = NULL;
handle.getArgument("subnet4collection", subnets);
if (subnets->empty()) {
return (0);
}
// Get registered_user pointer.
UserPtr registered_user;
handle.getContext(registered_user_label, registered_user);
if (registered_user) {
// User is in the registry, so leave the pre-selected subnet alone.
ConstSubnet4Ptr subnet;
handle.getArgument("subnet4", subnet);
} else {
// User is not in the registry, so assign them to the last subnet
// in the collection. By convention we are assuming this is the
// restricted subnet.
ConstSubnet4Ptr subnet = *subnets->rbegin();
handle.setArgument("subnet4", subnet);
}
} catch (const std::exception& ex) {
LOG_ERROR(user_chk_logger, USER_CHK_SUBNET4_SELECT_ERROR)
.arg(ex.what());
return (1);
}
return (0);
}
/// @brief This callout is called at the "subnet6_select" hook.
///
/// This function alters the selected subnet based upon whether or not the
/// requesting DHCP client is a "registered user". It fetches a pointer to
/// the registered user from the callout context. This value is presumed to
/// have been set upstream. If it is non-null that it points to the client's
/// user entry in the UserRegistry. If it is null, the client is not
/// registered.
///
/// If the client is registered, then replace the selected subnet with the
/// restricted access subnet. By convention, it is assumed that last subnet in
/// the list of available subnets is the restricted access subnet.
///
/// @param handle CalloutHandle which provides access to context.
///
/// @return 0 upon success, non-zero otherwise.
int subnet6_select(CalloutHandle& handle) {
CalloutHandle::CalloutNextStep status = handle.getStatus();
if (status == CalloutHandle::NEXT_STEP_DROP ||
status == CalloutHandle::NEXT_STEP_SKIP) {
return (0);
}
if (!user_registry) {
LOG_ERROR(user_chk_logger, USER_CHK_SUBNET6_SELECT_REGISTRY_NULL);
return (1);
}
try {
// Get subnet collection. If it's empty just bail nothing to do.
const isc::dhcp::Subnet6Collection *subnets = NULL;
handle.getArgument("subnet6collection", subnets);
if (subnets->empty()) {
return (0);
}
// Get registered_user pointer.
UserPtr registered_user;
handle.getContext(registered_user_label, registered_user);
if (registered_user) {
// User is in the registry, so leave the pre-selected subnet alone.
ConstSubnet6Ptr subnet;
handle.getArgument("subnet6", subnet);
} else {
// User is not in the registry, so assign them to the last subnet
// in the collection. By convention we are assuming this is the
// restricted subnet.
ConstSubnet6Ptr subnet = *subnets->rbegin();
handle.setArgument("subnet6", subnet);
}
} catch (const std::exception& ex) {
LOG_ERROR(user_chk_logger, USER_CHK_SUBNET6_SELECT_ERROR)
.arg(ex.what());
return (1);
}
return (0);
}
}
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