From 989841a0c4e83b0ac1b9d276be3797bcfa83bcb1 Mon Sep 17 00:00:00 2001
From: Phil Sutter <phil@nwl.cc>
Date: Sun, 27 Nov 2022 23:45:41 +0100
Subject: [PATCH] log: Try syslog if no log path was given

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 log.c      | 44 ++++++++++++++++++++++++++++++++++++++++++--
 minidlna.c |  2 --
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/log.c b/log.c
index a989904a24d93..840a8c02e678b 100644
--- a/log.c
+++ b/log.c
@@ -23,6 +23,7 @@
 #include <stdio.h>
 #include <stdarg.h>
 #include <string.h>
+#include <syslog.h>
 #include <time.h>
 
 #include "upnpglobalvars.h"
@@ -147,6 +148,40 @@ log_init(const char *debug)
 	return 0;
 }
 
+static int
+syslog_err(int level, enum _log_facility facility,
+	   char *fname, int lineno, char *fmt, va_list *ap)
+{
+	char myfmt[1024];
+	int level_to_syslog[E_MAXDEBUG + 1] = {
+		/* [E_OFF]	= 0, */
+		[E_FATAL]	= LOG_CRIT,
+		[E_ERROR]	= LOG_ERR,
+		[E_WARN]	= LOG_WARNING,
+		[E_INFO]	= LOG_NOTICE,
+		[E_DEBUG]	= LOG_INFO,
+		[E_MAXDEBUG]	= LOG_DEBUG,
+	};
+
+	if (level == E_OFF)
+		return 0;
+
+	if (level > E_MAXDEBUG)
+		return -1;
+
+	if (level)
+		snprintf(myfmt, 1024, "%s:%d: %s: %s", fname, lineno, level_name[level], fmt);
+	else
+		snprintf(myfmt, 1024, "%s:%d: %s", fname, lineno, fmt);
+
+	vsyslog(level_to_syslog[level], myfmt, *ap);
+
+	if (level == E_FATAL)
+		exit(-1);
+
+	return 0;
+}
+
 void
 log_err(int level, enum _log_facility facility, char *fname, int lineno, char *fmt, ...)
 {
@@ -155,8 +190,14 @@ log_err(int level, enum _log_facility facility, char *fname, int lineno, char *f
 	if (level && level>log_level[facility] && level>E_FATAL)
 		return;
 
-	if (!log_fp)
+	va_start(ap, fmt);
+	if (!log_fp) {
+		if (!syslog_err(level, facility, fname, lineno, fmt, &ap)) {
+			va_end(ap);
+			return;
+		}
 		log_fp = stdout;
+	}
 
 	// timestamp
 	if (!GETFLAG(SYSTEMD_MASK))
@@ -176,7 +217,6 @@ log_err(int level, enum _log_facility facility, char *fname, int lineno, char *f
 		fprintf(log_fp, "%s:%d: ", fname, lineno);
 
 	// user log
-	va_start(ap, fmt);
 	if (vfprintf(log_fp, fmt, ap) == -1)
 	{
 		va_end(ap);
diff --git a/minidlna.c b/minidlna.c
index 999adee977353..db29d603d1e28 100644
--- a/minidlna.c
+++ b/minidlna.c
@@ -817,8 +817,6 @@ init(int argc, char **argv)
 				optionsfile);
 		}
 	}
-	if (!log_path[0])
-		strncpyt(log_path, DEFAULT_LOG_PATH, sizeof(log_path));
 	if (!db_path[0])
 		strncpyt(db_path, DEFAULT_DB_PATH, sizeof(db_path));
 
-- 
2.38.1