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// Copyright (C) 2014 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
#include <config.h>
#include <dhcp4/json_config_parser.h>
#include <dhcp4/ctrl_dhcp4_srv.h>
#include <dhcp4/dhcp4_log.h>
#include <exceptions/exceptions.h>
#include <string>
using namespace isc::asiolink;
using namespace isc::dhcp;
using namespace std;
namespace {
/// @brief Configure DHCPv4 server using the configuration file specified.
///
/// This function is used to both configure the DHCP server on its startup
/// and dynamically reconfigure the server when SIGHUP signal is received.
///
/// It fetches DHCPv6 server's configuration from the 'Dhcp4' section of
/// the JSON configuration file.
///
/// @param file_name Configuration file location.
void configure(const std::string& file_name) {
// This is a configuration backend implementation that reads the
// configuration from a JSON file.
isc::data::ConstElementPtr json;
isc::data::ConstElementPtr dhcp4;
isc::data::ConstElementPtr result;
// Basic sanity check: file name must not be empty.
try {
if (file_name.empty()) {
// Basic sanity check: file name must not be empty.
isc_throw(isc::BadValue, "JSON configuration file not specified."
" Please use -c command line option.");
}
// Read contents of the file and parse it as JSON
json = isc::data::Element::fromJSONFile(file_name, true);
if (!json) {
LOG_ERROR(dhcp4_logger, DHCP4_CONFIG_LOAD_FAIL)
.arg("Config file " + file_name + " missing or empty.");
isc_throw(isc::BadValue, "Unable to process JSON configuration"
" file: " << file_name);
}
// Get Dhcp4 component from the config
dhcp4 = json->get("Dhcp4");
if (!dhcp4) {
LOG_ERROR(dhcp4_logger, DHCP4_CONFIG_LOAD_FAIL)
.arg("Config file " + file_name + " does not include 'Dhcp4'"
" entry.");
isc_throw(isc::BadValue, "Unable to process JSON configuration"
" file: " << file_name);
}
// Use parsed JSON structures to configure the server
result = ControlledDhcpv4Srv::processCommand("config-reload", dhcp4);
} catch (const std::exception& ex) {
LOG_ERROR(dhcp4_logger, DHCP4_CONFIG_LOAD_FAIL).arg(ex.what());
isc_throw(isc::BadValue, "Unable to process JSON configuration file: "
<< file_name);
}
if (!result) {
// Undetermined status of the configuration. This should never happen,
// but as the configureDhcp4Server returns a pointer, it is
// theoretically possible that it will return NULL.
LOG_ERROR(dhcp4_logger, DHCP4_CONFIG_LOAD_FAIL)
.arg("Configuration failed: Undefined result of processCommand("
"config-reload, " + file_name + ")");
isc_throw(isc::BadValue, "Configuration failed: Undefined result of "
"processCommand('config-reload', " << file_name << ")");
}
// Now check is the returned result is successful (rcode=0) or not
isc::data::ConstElementPtr comment; /// see @ref isc::config::parseAnswer
int rcode;
comment = isc::config::parseAnswer(rcode, result);
if (rcode != 0) {
string reason = "";
if (comment) {
reason = string(" (") + comment->stringValue() + string(")");
}
LOG_ERROR(dhcp4_logger, DHCP4_CONFIG_LOAD_FAIL).arg(reason);
isc_throw(isc::BadValue, "Failed to apply configuration: " << reason);
}
}
/// @brief Signals handler for DHCPv4 server.
///
/// This signal handler handles the following signals received by the DHCPv4
/// server process:
/// - SIGHUP - triggers server's dynamic reconfiguration.
/// - SIGTERM - triggers server's shut down.
/// - SIGINT - triggers server's shut down.
///
/// @param signo Signal number received.
void signalHandler(int signo) {
// SIGHUP signals a request to reconfigure the server.
if (signo == SIGHUP) {
// Get configuration file name.
std::string file = ControlledDhcpv4Srv::getInstance()->getConfigFile();
try {
LOG_INFO(dhcp4_logger, DHCP4_DYNAMIC_RECONFIGURATION).arg(file);
configure(file);
} catch (const std::exception& ex) {
// Log the unsuccessful reconfiguration. The reason for failure
// should be already logged. Don't rethrow an exception so as
// the server keeps working.
LOG_ERROR(dhcp4_logger, DHCP4_DYNAMIC_RECONFIGURATION_FAIL)
.arg(file);
}
} else if ((signo == SIGTERM) || (signo == SIGINT)) {
isc::data::ElementPtr params(new isc::data::MapElement());
ControlledDhcpv4Srv::processCommand("shutdown", params);
}
}
}
namespace isc {
namespace dhcp {
void
ControlledDhcpv4Srv::init(const std::string& file_name) {
// Call parent class's init to initialize file name.
Daemon::init(file_name);
// Configure the server using JSON file.
configure(file_name);
// We don't need to call openActiveSockets() or startD2() as these
// methods are called in processConfig() which is called by
// processCommand("reload-config", ...)
// Set signal handlers. When the SIGHUP is received by the process
// the server reconfiguration will be triggered. When SIGTERM or
// SIGINT will be received, the server will start shutting down.
signal_set_.reset(new isc::util::io::SignalSet(SIGINT, SIGHUP, SIGTERM));
// Set the pointer to the handler function.
signal_handler_ = signalHandler;
}
void ControlledDhcpv4Srv::cleanup() {
// Nothing to do here. No need to disconnect from anything.
}
/// This is a logger initialization for JSON file backend.
/// For now, it's just setting log messages to be printed on stdout.
/// @todo: Implement this properly (see #3427)
void Daemon::loggerInit(const char*, bool verbose) {
setenv("B10_LOCKFILE_DIR_FROM_BUILD", "/tmp", 1);
setenv("B10_LOGGER_ROOT", "kea", 0);
setenv("B10_LOGGER_SEVERITY", (verbose ? "DEBUG":"INFO"), 0);
setenv("B10_LOGGER_DBGLEVEL", "99", 0);
setenv("B10_LOGGER_DESTINATION", "stdout", 0);
isc::log::initLogger();
}
};
};
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