From 168f5bf1d86c62c1fc62a7c79890a874e47b2e21 Mon Sep 17 00:00:00 2001
From: Joachim Wiberg <troglobit@gmail.com>
Date: Wed, 2 Jul 2025 14:25:42 +0200
Subject: [PATCH] log: new function, log_parse()

Converts from syslog priority string format to facility and level.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
---
 src/log.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/log.h |  1 +
 2 files changed, 71 insertions(+)

diff --git a/src/log.c b/src/log.c
index 7eb80d62..7a50b6f4 100644
--- a/src/log.c
+++ b/src/log.c
@@ -32,6 +32,9 @@
 # include <lite/lite.h>
 #endif
 
+#define SYSLOG_NAMES
+#include <syslog.h>
+
 #include "finit.h"
 #include "helpers.h"
 #include "log.h"
@@ -106,6 +109,73 @@ static const char *l2s(int prio)
         return "UNK";
 }
 
+static int s2f(const char *str)
+{
+	for (int i = 0; facilitynames[i].c_name; i++) {
+		if (string_match(facilitynames[i].c_name, str))
+			return facilitynames[i].c_val;
+	}
+
+	return -1;
+}
+
+static int s2l(const char *str)
+{
+	for (int i = 0; prioritynames[i].c_name; i++) {
+		if (string_match(prioritynames[i].c_name, str))
+			return prioritynames[i].c_val;
+	}
+
+	return -1;
+}
+
+/*
+ * Parse syslog facility.priority strings into their numerical values
+ * using arrays defined in <syslog.h>.  Note, the 'prio' argument may
+ * be one of:
+ *
+ *  - facility.level
+ *  - facility
+ *  - level
+ *
+ * It is up to the callee to assign defaults to 'facility' and 'level'
+ * before calling this function.  If There is any match the respective
+ * facility or level will be assigned and this function returns OK.
+ */
+int log_parse(char *prio, int *facility, int *level)
+{
+	char *fac = prio, *lvl;
+	int f = -1;
+	int l = -1;
+
+	if (!prio || !facility || !level)
+		return -1;
+
+	lvl = strchr(prio, '.');
+	if (lvl) {
+		*lvl = 0;
+		lvl++;
+	}
+
+	if (lvl && *lvl)
+		l = s2l(lvl);
+
+	f = s2f(fac);
+	if (l < 0)
+		l = s2l(fac);
+
+	if (l < 0 && f <= 0)
+		return -1;
+
+	if (l <= LOG_DEBUG)
+		*level = l;
+
+	if (f <= LOG_LOCAL7)
+		*facility = f;
+
+	return 0;
+}
+
 /*
  * Log to /dev/kmsg until syslogd has started, then openlog()
  * and continue logging as a regular daemon.
diff --git a/src/log.h b/src/log.h
index 4a449484..ee6097f9 100644
--- a/src/log.h
+++ b/src/log.h
@@ -78,6 +78,7 @@ void    log_init (void);
 void    log_exit (void);
 
 void    log_debug(void);
+int     log_parse(char *prio, int *facility, int *level);
 
 void    logit    (int prio, const char *fmt, ...)   __attribute__ ((format (printf, 2, 3)));
 void    flog     (char *file, const char *fmt, ...) __attribute__ ((format (printf, 2, 3)));