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/*
* This file is part of PowerDNS or dnsdist.
* Copyright -- PowerDNS.COM B.V. and its contributors
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* In addition, for the avoidance of any doubt, permission is granted to
* link this program with OpenSSL and to (re)distribute the binaries
* produced as the result of such linking.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#pragma once
#include <fstream>
#include <iostream>
#include <optional>
#include <sstream>
#include "config.h"
#if !defined(RECURSOR)
#include <syslog.h>
#else
#include "logger.hh"
#endif // RECURSOR
/* This file is intended not to be metronome specific, and is simple example of C++2011
variadic templates in action.
The goal is rapid easy to use logging to console & syslog.
Usage:
string address="localhost";
vinfolog("Got TCP connection from %s", remote);
infolog("Bound to %s port %d", address, port);
warnlog("Query took %d milliseconds", 1232.4); // yes, %d
errlog("Unable to bind to %s: %s", ca.toStringWithPort(), strerr(errno));
Will log to stdout. Will syslog in any case with LOG_INFO,
LOG_WARNING, LOG_ERR respectively. If g_verbose=false, vinfolog is a noop.
More generically, dolog(someiostream, "Hello %s", stream) will log to someiostream
This will happily print a string to %d! Doesn't do further format processing.
*/
#if !defined(RECURSOR)
inline void dolog(std::ostream& os, const char*s)
{
os<<s;
}
template<typename T, typename... Args>
void dolog(std::ostream& os, const char* s, T value, Args... args)
{
while (*s) {
if (*s == '%') {
if (*(s + 1) == '%') {
++s;
}
else {
os << value;
s += 2;
dolog(os, s, args...);
return;
}
}
os << *s++;
}
}
extern bool g_verbose;
extern bool g_syslog;
#ifdef DNSDIST
extern bool g_logtimestamps;
extern std::optional<std::ofstream> g_verboseStream;
#endif
inline void setSyslogFacility(int facility)
{
/* we always call openlog() right away at startup */
closelog();
openlog("dnsdist", LOG_PID|LOG_NDELAY, facility);
}
template<typename... Args>
void genlog(std::ostream& stream, int level, bool doSyslog, const char* s, Args... args)
{
std::ostringstream str;
dolog(str, s, args...);
auto output = str.str();
if (doSyslog) {
syslog(level, "%s", output.c_str());
}
#ifdef DNSDIST
if (g_logtimestamps) {
char buffer[50] = "";
struct tm tm;
time_t t;
time(&t);
localtime_r(&t, &tm);
if (strftime(buffer, sizeof(buffer), "%b %d %H:%M:%S ", &tm) == 0) {
buffer[0] = '\0';
}
stream<<buffer;
}
#endif
stream<<output<<std::endl;
}
template<typename... Args>
void verboselog(const char* s, Args... args)
{
#ifdef DNSDIST
if (g_verboseStream) {
genlog(*g_verboseStream, LOG_DEBUG, false, s, args...);
}
else {
#endif /* DNSDIST */
genlog(std::cout, LOG_DEBUG, g_syslog, s, args...);
#ifdef DNSDIST
}
#endif /* DNSDIST */
}
#define vinfolog if (g_verbose) verboselog
template<typename... Args>
void infolog(const char* s, Args... args)
{
genlog(std::cout, LOG_INFO, g_syslog, s, args...);
}
template<typename... Args>
void warnlog(const char* s, Args... args)
{
genlog(std::cout, LOG_WARNING, g_syslog, s, args...);
}
template<typename... Args>
void errlog(const char* s, Args... args)
{
genlog(std::cout, LOG_ERR, g_syslog, s, args...);
}
#else // RECURSOR
#define g_verbose 0
inline void dolog(Logger::Urgency u, const char* s)
{
g_log << u << s << std::endl;
}
inline void dolog(const char* s)
{
g_log << s << std::endl;
}
template<typename T, typename... Args>
void dolog(Logger::Urgency u, const char* s, T value, Args... args)
{
g_log << u;
while (*s) {
if (*s == '%') {
if (*(s + 1) == '%') {
++s;
}
else {
g_log << value;
s += 2;
dolog(s, args...);
return;
}
}
g_log << *s++;
}
}
#define vinfolog if(g_verbose)infolog
template<typename... Args>
void infolog(const char* s, Args... args)
{
dolog(Logger::Info, s, args...);
}
template<typename... Args>
void warnlog(const char* s, Args... args)
{
dolog(Logger::Warning, s, args...);
}
template<typename... Args>
void errlog(const char* s, Args... args)
{
dolog(Logger::Error, s, args...);
}
#endif
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