From 0e44d64d25bc347cfb462d720f5f6d4ac47167a3 Mon Sep 17 00:00:00 2001
From: DL6ER <dl6er@dl6er.de>
Date: Sat, 5 Apr 2025 10:33:09 +0200
Subject: [PATCH 1/3] Add search_proc() function

Signed-off-by: DL6ER <dl6er@dl6er.de>
---
 src/procps.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/procps.h |  1 +
 2 files changed, 57 insertions(+)

diff --git a/src/procps.c b/src/procps.c
index e74c5775..5e4d855b 100644
--- a/src/procps.c
+++ b/src/procps.c
@@ -359,3 +359,59 @@ bool parse_proc_stat(unsigned long *total_sum, unsigned long *idle_sum)
 
 	return true;
 }
+
+/**
+ * @brief Searches for a process by its name in the /proc filesystem.
+ *
+ * This function iterates through the directories in /proc, which represent
+ * process IDs (PIDs), and checks the "comm" file in each directory to find
+ * a process with a matching name.
+ *
+ * @param name The name of the process to search for.
+ *
+ * @return The PID of the process if found, or -1 if no matching process is found
+ *         or if an error occurs (e.g., unable to open /proc or a file).
+ *
+ * @note This function assumes the /proc filesystem is available and accessible.
+ *       It also assumes that the "comm" file in each process directory contains
+ *       the name of the process.
+ */
+pid_t search_proc(const char *name)
+{
+	DIR *dir = opendir("/proc");
+	if(dir == NULL)
+		return -1;
+
+	struct dirent *entry;
+	while((entry = readdir(dir)) != NULL)
+	{
+		// Check if the entry is a directory and contains only digits
+		// We skip ".", "..", "self", and friends
+		if(entry->d_type == DT_DIR && isdigit(entry->d_name[0]))
+		{
+			char filename[64];
+			snprintf(filename, sizeof(filename), "/proc/%s/comm", entry->d_name);
+			FILE *file = fopen(filename, "r");
+			if(file != NULL)
+			{
+				char comm[PROC_PATH_SIZ + 1] = { 0 };
+				// Read the command name from the file
+				if(fscanf(file, "%"xstr(PROC_PATH_SIZ)"s", comm) == 1)
+				{
+					if(strcmp(comm, name) == 0)
+					{
+						// Found a matching process
+						fclose(file);
+						closedir(dir);
+						return atoi(entry->d_name);
+					}
+				}
+				fclose(file);
+			}
+		}
+	}
+
+	// No process found with the given name
+	closedir(dir);
+	return -1;
+}
diff --git a/src/procps.h b/src/procps.h
index f5f6fae7..af441686 100644
--- a/src/procps.h
+++ b/src/procps.h
@@ -49,5 +49,6 @@ struct proc_meminfo {
 bool getProcessMemory(struct proc_mem *mem, const unsigned long total_memory);
 bool parse_proc_meminfo(struct proc_meminfo *mem);
 bool parse_proc_stat(unsigned long *total_sum, unsigned long *idle_sum);
+pid_t search_proc(const char *name);
 
 #endif // PROCPS_H

From 17d6232fbcc7ee43d412f13e54ba8b06123d8589 Mon Sep 17 00:00:00 2001
From: DL6ER <dl6er@dl6er.de>
Date: Sat, 5 Apr 2025 10:36:12 +0200
Subject: [PATCH 2/3] Add check for existing clock disciplining NTP clients
 before starting embedded NTP server

---
 src/ntp/client.c | 9 +++++++++
 test/libs/bats   | 1 +
 2 files changed, 10 insertions(+)
 create mode 160000 test/libs/bats

diff --git a/src/ntp/client.c b/src/ntp/client.c
index 159b5b62..7d62c977 100644
--- a/src/ntp/client.c
+++ b/src/ntp/client.c
@@ -41,6 +41,8 @@
 #include "database/message-table.h"
 // check_capability()
 #include "capabilities.h"
+// search_proc()
+#include "procps.h"
 
 // Required accuracy of the NTP sync in seconds in order to start the NTP server
 // thread. If the NTP sync is less accurate than this value, the NTP server
@@ -746,6 +748,13 @@ bool ntp_start_sync_thread(pthread_attr_t *attr)
 		ntp_server_start();
 		return false;
 	}
+	// Return early if a clock disciplining NTP client is detected
+	// Checks chrony, the ntp family (ntp, ntpsec and openntpd), and ntpd-rs
+	if(search_proc("chronyd") > 0 || search_proc("ntpd") > 0 || search_proc("ntp-daemon") > 0)
+	{
+		log_info("Clock disciplining NTP client detected, not starting embedded NTP client/server");
+		return false;
+	}
 
 	// Check if we have the ambient capabilities to set the system time.
 	// Without CAP_SYS_TIME, we cannot set the system time and the NTP
diff --git a/test/libs/bats b/test/libs/bats
new file mode 160000
index 00000000..429e8641
--- /dev/null
+++ b/test/libs/bats
@@ -0,0 +1 @@
+Subproject commit 429e86417b52f09d491778bb3cd14eaa1d25462f

From 455ff634e348bc47fa429c111b02e8fcdba39c56 Mon Sep 17 00:00:00 2001
From: DL6ER <dl6er@dl6er.de>
Date: Wed, 16 Apr 2025 20:19:41 +0200
Subject: [PATCH 3/3] Undo submodule addition

Signed-off-by: DL6ER <dl6er@dl6er.de>
---
 test/libs/bats | 1 -
 1 file changed, 1 deletion(-)
 delete mode 160000 test/libs/bats

diff --git a/test/libs/bats b/test/libs/bats
deleted file mode 160000
index 429e8641..00000000
--- a/test/libs/bats
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 429e86417b52f09d491778bb3cd14eaa1d25462f