Enabling Luks service manager as daemon service

Added functionality to run luks-fs-mgr as daemon
service. Included library libdaemon which provides functions and
utilities to daemonize a program.
The daemon function is called to daemonize the program.
The daemon function is provided by libdaemon, and it sets up the
necessary environment for a daemon process. It is called with two
arguments, both set to 0. The first argument is the nochdir
parameter, which tells the function not to change the current
working directory to the root directory ("/").
The second argument is the noclose parameter, which tells the
function not to close standard input, output, and error streams.

Depends on: https://review.opendev.org/c/starlingx/integ/+/898695

Test Plan:
PASSED: build-pkgs -c -p luks-fs-mgr
PASSED: build-image
PASSED: AIO-SX bootstrap
PASSED: binary available at /usr/local/sbin/
PASSED: systemd unit file available at /lib/systemd/system
PASSED: luks_config.json avaiable at /etc/luks-fs-mgr.d/
PASSED: sudo systemctl start luks-fs-mgr
        luks-fs-mgr.service - Create and mount encrypted vault using
                                                                LUKS
        Loaded: loaded (/lib/systemd/system/luks-fs-mgr.service;
                                enabled; vendor preset: enabled)
        Active: active (running) since Fri 2023-10-13 05:58:04 UTC;
                                                       1h 34min ago
        Main PID: 1770 (luks-fs-mgr)
        Tasks: 1 (limit: 28602)
        Memory: 2.1M
        CPU: 3.422s
        CGroup: /system.slice/luks-fs-mgr.service
                └─1770 /usr/local/sbin/luks-fs-mgr start
PASSED: sudo systemctl stop luks-fs-mgr

Story: 2010872
Task: 48944

Change-Id: I975409d749fed8f27b291db80fa10223de60b05c
Signed-off-by: Rahul Roshan Kachchap <rahulroshan.kachchap@windriver.com>

filesystem/luks/debian/deb_folder/control

@@ -3,7 +3,8 @@ Section: admin
 Priority: optional
 Maintainer: StarlingX Developers <starlingx-discuss@lists.starlingx.io>
 Build-Depends: debhelper-compat (= 13),
- libjson-c-dev
+ libjson-c-dev,
+ libdaemon-dev
 Standards-Version: 4.5.1
 Homepage: https://www.starlingx.io
 

filesystem/luks/debian/deb_folder/luks-fs-mgr.service

@@ -3,9 +3,12 @@ Description=Create and mount encrypted vault using LUKS
 After=local-fs.target network-online.target
 
 [Service]
-Type=oneshot
+Type=forking
 ExecStart=/usr/local/sbin/luks-fs-mgr start
-PIDFile=/var/run/luks-fs-mgr.pid
+User=root
+Group=root
+KillMode=process
+SendSIGKILL=no
 
 [Install]
 WantedBy=multi-user.target

filesystem/luks/src/encryption/Makefile

@@ -7,7 +7,7 @@
 SHELL = /bin/bash
 
 CFLAGS = -Wall -Wextra -g -Werror -std=c++11
-LIBS = -lstdc++ -ljson-c
+LIBS = -lstdc++ -ljson-c -ldaemon
 INCLUDES = -I.
 
 CC=g++

filesystem/luks/src/encryption/luks-fs-mgr.cpp

@@ -14,6 +14,7 @@
 #include <json-c/json.h>
 #include <syslog.h>
 #include <unistd.h>
+#include <libdaemon/daemon.h>
 #include <iostream>
 #include <string>
 #include <cstdlib>
@@ -21,6 +22,8 @@
 #include <type_traits>
 #include "PassphraseGenerator.h"
 
+#define SLEEP_DURATION 60
+
 using namespace std;
 
 // Global constants
@@ -707,8 +710,40 @@ bool resizeVault(const char* vaultFile,
     }
 }
 
+/* ***********************************************************************
+ *
+ * Name       : monitorLUKSVolume
+ *
+ * Description: This function monitors the LUKS volume status and runs
+ *              in loop until there's any issue with the LUKS volume.
+ *
+ * ************************************************************************/
+
+void monitorLUKSVolume(const string& volumeName) {
+    while (1) {
+        string statusCommand = "cryptsetup status " + volumeName +
+                                                           " 2>/dev/null";
+        int status = system(statusCommand.c_str());
+            if (status != 0) {
+                string errorMessage = "LUKS volume is not in use. "
+                                      "Error code: " + to_string(status);
+                log(errorMessage, LOG_ERR);
+                break;
+            }
+            sleep(SLEEP_DURATION);
+        }
+}
+
 int main() {
     int rc = 0;
+    int ret = daemon(0, 0);
+    if (ret != 0) {
+        string errorMessage = "Failed to run luks-fs-mgr as daemon service. "
+                              "Error code: " + to_string(ret);
+        log(errorMessage, LOG_ERR);
+        return 1;
+    }
+
     LuksConfig luksConfig;
     CreatedLuksConfig createdLuksConfig;
     string passphrase;
@@ -723,10 +758,10 @@ int main() {
     PassphraseMechanism selectedMechanism = passPhraseType();
     auto passphraseGenerator =
       PassphraseGeneratorFactory::createPassphraseGenerator(selectedMechanism);
-    bool ret = passphraseGenerator->generatePassphrase(passphrase);
+    bool passStatus = passphraseGenerator->generatePassphrase(passphrase);
 
     // Validating if passphrase is empty
-    if (passphrase.empty() || ret == false) {
+    if (passphrase.empty() || passStatus == false) {
         log("Passphrase generation failed or"
                             " returned an empty passphrase.", LOG_ERR);
         rc = 1;
@@ -786,6 +821,7 @@ int main() {
         int createdsize = 0;
         defaultsize = checkVaultSize(luksConfig.vaultSize);
         createdsize = checkVaultSize(createdLuksConfig.vaultSize);
+        string volName = string(createdLuksConfig.volName);
         if (defaultsize > createdsize) {
             log("Resizing the vault file.", LOG_INFO);
             if (resizeVault(createdLuksConfig.vaultFile,
@@ -834,7 +870,7 @@ int main() {
                 // or device is block device
                 // 1: failure; incorrect invocation, permissions or system error
                 // 32: failure; the directory is not a mountpoint,
-                // or device is not a block device on
+                // or device is not a block device
                 if (mountpoint_status != 0) {
                     // Mount path directory is not mount point,
                     // proceed to mount it
@@ -863,8 +899,9 @@ int main() {
             log("Encrypted vault is mounted.", LOG_INFO);
             }
         }
-    rc = 0;
-    goto cleanup;
+        monitorLUKSVolume(volName);
+        rc = 0;
+        goto cleanup;
     } else {
         // Execute the below code when service start during first boot
         // Create default directory for the service to create FS and mount
@@ -882,6 +919,7 @@ int main() {
         // Create a new string to hold the created values
         string modifiedVaultFile = luksConfig.vaultFile;
         string mountPath = luksConfig.mountPath;
+        string volName = luksConfig.volName;
         // Check if directory path is provided in vaultFile
         size_t lastSlashPos = modifiedVaultFile.rfind('/');
         if (lastSlashPos == string::npos) {
@@ -1027,6 +1065,7 @@ int main() {
             rc = 1;
             goto cleanup;
         }
+        monitorLUKSVolume(volName);
         rc = 0;
         goto cleanup;
     }