From 70fff27c46d85bc9984494158bebae3a8bd6e732 Mon Sep 17 00:00:00 2001
From: DL6ER <dl6er@dl6er.de>
Date: Sun, 15 Jan 2023 20:43:38 +0100
Subject: [PATCH] Check if temperature sensors exist before reading them to
 avoid spamming the log with "no such file or directory" messages for sensors
 without labels

Signed-off-by: DL6ER <dl6er@dl6er.de>
---
 src/api/ftl.c               | 15 ++++++++---
 src/config/dnsmasq_config.c |  4 +--
 src/files.c                 | 52 +++++++++++++++++++++++--------------
 src/files.h                 |  2 +-
 4 files changed, 47 insertions(+), 26 deletions(-)

diff --git a/src/api/ftl.c b/src/api/ftl.c
index 88f09151..47bc89a9 100644
--- a/src/api/ftl.c
+++ b/src/api/ftl.c
@@ -210,7 +210,11 @@ static int read_temp_sensor(struct ftl_conn *api,
                             const char *short_path,
                             cJSON *object)
 {
-	FILE *f_label = fopen(label_path, "r");
+	// Check if sensor is available
+	if(file_exists(value_path) == false)
+		return 0;
+
+	// Open files
 	FILE *f_value = fopen(value_path, "r");
 	if(f_value != NULL)
 	{
@@ -218,6 +222,10 @@ static int read_temp_sensor(struct ftl_conn *api,
 		char label[1024];
 		if(fscanf(f_value, "%d", &raw_temp) == 1)
 		{
+			FILE *f_label = NULL;
+			if(file_exists(label_path))
+				f_label = fopen(label_path, "r");
+
 			cJSON *item = JSON_NEW_OBJECT();
 			if(f_label && fgets(label, sizeof(label)-1, f_label))
 			{
@@ -232,6 +240,9 @@ static int read_temp_sensor(struct ftl_conn *api,
 			}
 			JSON_COPY_STR_TO_OBJECT(item, "path", short_path);
 
+			if(f_label != NULL)
+				fclose(f_label);
+
 			// Compute actual temperature
 			double temp = raw_temp < 1000 ? raw_temp : 1e-3*raw_temp;
 			const char *unit = "C";
@@ -251,8 +262,6 @@ static int read_temp_sensor(struct ftl_conn *api,
 			JSON_ADD_ITEM_TO_ARRAY(object, item);
 		}
 	}
-	if(f_label != NULL)
-		fclose(f_label);
 	if(f_value != NULL)
 		fclose(f_value);
 
diff --git a/src/config/dnsmasq_config.c b/src/config/dnsmasq_config.c
index 65e685f4..45a02c06 100644
--- a/src/config/dnsmasq_config.c
+++ b/src/config/dnsmasq_config.c
@@ -20,7 +20,7 @@
 #include "config/config.h"
 // JSON array functions
 #include "cJSON/cJSON.h"
-// directoryExists()
+// directory_exists()
 #include "files.h"
 
 #define DNSMASQ_PH_CONFIG "/etc/pihole/dnsmasq.conf"
@@ -290,7 +290,7 @@ bool __attribute__((const)) write_dnsmasq_config(bool test_config)
 	fputs("server=/bind/\n", pihole_conf);
 	fputs("server=/onion/\n", pihole_conf);
 
-	if(directoryExists("/etc/dnsmasq.d"))
+	if(directory_exists("/etc/dnsmasq.d"))
 	{
 		// Load possible additional user scripts from /etc/dnsmasq.d if
 		// the directory exists (it may not, e.g., in a container)
diff --git a/src/files.c b/src/files.c
index 92c5f8c0..abb3e3f9 100644
--- a/src/files.c
+++ b/src/files.c
@@ -59,10 +59,40 @@ bool chmod_file(const char *filename, const mode_t mode)
 	return true;
 }
 
+/**
+ * Function to check whether a file exists or not.
+ * It returns true if given path is a file and exists
+ * otherwise returns false.
+ */
 bool file_exists(const char *filename)
 {
-	struct stat st;
-	return stat(filename, &st) == 0;
+	struct stat stats = { 0 };
+	if(stat(filename, &stats) != 0)
+	{
+		// Directory does not exist
+		return false;
+	}
+
+	// Check if this is a directory
+	return S_ISREG(stats.st_mode);
+}
+
+/**
+ * Function to check whether a directory exists or not.
+ * It returns true if given path is a directory and exists
+ * otherwise returns false.
+ */
+bool directory_exists(const char *path)
+{
+	struct stat stats = { 0 };
+	if(stat(path, &stats) != 0)
+	{
+		// Directory does not exist
+		return false;
+	}
+
+	// Check if this is a directory
+	return S_ISDIR(stats.st_mode);
 }
 
 bool get_database_stat(struct stat *st)
@@ -234,24 +264,6 @@ static char *trim(char *str)
 	return start;
 }
 
-/**
- * Function to check whether a directory exists or not.
- * It returns 1 if given path is directory and  exists
- * otherwise returns 0.
- */
-bool directoryExists(const char *path)
-{
-	struct stat stats = { 0 };
-	if(stat(path, &stats) != 0)
-	{
-		// Directory does not exist
-		return false;
-	}
-
-	// Check if this is a directory
-	return S_ISDIR(stats.st_mode);
-}
-
 // Credits: https://stackoverflow.com/a/55410469
 int parse_line(char *line, char **key, char **value)
 {
diff --git a/src/files.h b/src/files.h
index c636ba79..e1c332a8 100644
--- a/src/files.h
+++ b/src/files.h
@@ -18,7 +18,7 @@ void get_permission_string(char permissions[10], struct stat *st);
 void ls_dir(const char* path);
 int get_path_usage(const char *path, char buffer[64]);
 int get_filepath_usage(const char *file, char buffer[64]);
-bool directoryExists(const char *path);
+bool directory_exists(const char *path);
 
 int parse_line(char *line, char **key, char **value);