From: Lukáš Ježek <lukas.jezek@nic.cz>
Date: Thu, 13 May 2021 08:50:57 +0000 (+0200)
Subject: log: add syslog target, systemd
X-Git-Tag: v5.4.0~2^2~59
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c1cb8c56cdd44d2e76ba6898ebc709fdb0fe3207;p=thirdparty%2Fknot-resolver.git

log: add syslog target, systemd
---

diff --git a/daemon/main.c b/daemon/main.c
index e24a7653f..b57a9ebdf 100644
--- a/daemon/main.c
+++ b/daemon/main.c
@@ -422,7 +422,7 @@ int main(int argc, char **argv)
 
 	the_args = &the_args_value;
 	args_init(the_args);
-	kr_log_init(LOG_WARNING);
+	kr_log_init(LOG_WARNING, LOG_TARGET_STDOUT);
 	int ret = parse_args(argc, argv, the_args);
 	if (ret >= 0) goto cleanup_args;
 
diff --git a/lib/log.c b/lib/log.c
index 5bcb14920..2b80091ae 100644
--- a/lib/log.c
+++ b/lib/log.c
@@ -2,19 +2,63 @@
  *  SPDX-License-Identifier: GPL-3.0-or-later
  */
 
+#include "kresconfig.h"
+
 #include <stdio.h>
 #include <gnutls/gnutls.h>
 #include "lib/log.h"
 
+#if ENABLE_LIBSYSTEMD
+#include <stdlib.h>
+#include <systemd/sd-daemon.h>
+#include <systemd/sd-journal.h>
+
+int use_journal = 0;
+#endif
+
 log_level_t kr_log_level = LOG_CRIT;
+log_target_t kr_log_target = LOG_TARGET_STDOUT;
+
 
 void kr_log_fmt(log_level_t level, const char *fmt, ...)
 {
 	va_list args;
-	va_start(args, fmt);
-	if (KR_LOG_LEVEL_IS(level))
-		vfprintf(stdout, fmt, args);
-	va_end(args);
+
+	if (kr_log_target == LOG_TARGET_SYSLOG) {
+		va_start(args, fmt);
+#if ENABLE_LIBSYSTEMD
+		if (use_journal) {
+			char *code_line = NULL;
+			if (asprintf(&code_line, "%d", __LINE__) == -1) {
+				sd_journal_printv(level, fmt, args);
+			} else {
+				sd_journal_printv_with_location(level,
+						__FILE__, code_line, __func__,
+						fmt, args);
+				free(code_line);
+			}
+		} else {
+			vsyslog(level, fmt, args);
+		}
+#else
+		vsyslog(level, fmt, args);
+#endif
+		va_end(args);
+	} else {
+		if (!KR_LOG_LEVEL_IS(level))
+			return;
+
+		FILE *stream;
+		switch(kr_log_target) {
+		case LOG_TARGET_STDOUT: stream = stdout; break;
+		case LOG_TARGET_STDERR: stream = stderr; break;
+		default: stream = stdout; break;
+		}
+
+		va_start(args, fmt);
+		vfprintf(stream, fmt, args);
+		va_end(args);
+	}
 }
 
 static void kres_gnutls_log(int level, const char *message)
@@ -28,6 +72,7 @@ int kr_log_level_set(log_level_t level)
 		return kr_log_level;
 
 	kr_log_level = level;
+	setlogmask(LOG_UPTO(kr_log_level));
 
 	/* gnutls logs messages related to our TLS and also libdnssec,
 	 * and the logging is set up in a global way only */
@@ -46,8 +91,15 @@ log_level_t kr_log_level_get(void)
 	return kr_log_level;
 }
 
-void kr_log_init(log_level_t level)
+void kr_log_init(log_level_t level, log_target_t target)
 {
 	kr_log_level = level;
+	kr_log_target = target;
+
+#if ENABLE_LIBSYSTEMD
+	use_journal = sd_booted();
+#endif
+	openlog(NULL, LOG_PID, LOG_DAEMON);
+	setlogmask(LOG_UPTO(kr_log_level));
 }
 
diff --git a/lib/log.h b/lib/log.h
index 476b18b43..bce8e08f3 100644
--- a/lib/log.h
+++ b/lib/log.h
@@ -5,22 +5,29 @@
 #pragma once
 
 #include <stdarg.h>
+#include <syslog.h>
 #include "lib/defines.h"
 
+typedef int log_level_t;
+
 typedef enum {
-	LOG_CRIT = 0,
-	LOG_ERR,
-	LOG_WARNING,
-	LOG_NOTICE,
-	LOG_INFO,
-	LOG_DEBUG
-} log_level_t;
-
-KR_EXPORT KR_PRINTF(2) void kr_log_fmt(log_level_t level, const char *fmt, ...);
-KR_EXPORT extern log_level_t kr_log_level;
-KR_EXPORT int kr_log_level_set(log_level_t level);
-KR_EXPORT log_level_t kr_log_level_get(void);
-void kr_log_init(log_level_t level);
+	LOG_TARGET_SYSLOG = 0,
+	LOG_TARGET_STDERR = 1,
+	LOG_TARGET_STDOUT = 2,
+} log_target_t;
+
+KR_EXPORT
+extern log_level_t kr_log_level;
+KR_EXPORT
+extern log_target_t kr_log_target;
+KR_EXPORT KR_PRINTF(2)
+void kr_log_fmt(log_level_t level, const char *fmt, ...);
+KR_EXPORT
+int kr_log_level_set(log_level_t level);
+KR_EXPORT
+log_level_t kr_log_level_get(void);
+KR_EXPORT
+void kr_log_init(log_level_t level, log_target_t target);
 
 #define kr_log_debug(fmt, ...) kr_log_fmt(LOG_DEBUG, fmt, ## __VA_ARGS__)
 #define kr_log_info(fmt, ...) kr_log_fmt(LOG_INFO, fmt, ## __VA_ARGS__)
diff --git a/lib/meson.build b/lib/meson.build
index 2098b343b..d02bfe99d 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -101,6 +101,7 @@ libkres_lib = library('kres',
     libdnssec,
     gnutls,
     luajit,
+    libsystemd,
   ],
   install: true,
 )