From dfa3c733dc6190ed2915032573dcdcb6e344ebd1 Mon Sep 17 00:00:00 2001
From: Yang Song <yangsongcn@google.com>
Date: Thu, 31 Oct 2024 07:48:53 +0000
Subject: [PATCH] Add pd daemon service: using systemd to run pd daemon service

---
 script/_dhcpv6_pd_ref                      | 70 +++++++++++++++++++---
 script/reference-device/dhcp6_pd_daemon.py | 59 +++++++++++-------
 2 files changed, 100 insertions(+), 29 deletions(-)

diff --git a/script/_dhcpv6_pd_ref b/script/_dhcpv6_pd_ref
index b431ce625da..ab6069add9d 100644
--- a/script/_dhcpv6_pd_ref
+++ b/script/_dhcpv6_pd_ref
@@ -30,11 +30,17 @@
 #       This script manipulates DHCPv6-PD-REF configuration.
 #
 
-customise_dhcpcd_conf()
+DHCPCD_ENTER_HOOK="/etc/dhcpcd.enter-hook"
+DHCPCD_EXIT_HOOK="/etc/dhcpcd.exit-hook"
+
+PD_DAEMON_PATH="/opt/pd-daemon"
+PD_DAEMON="${PD_DAEMON_PATH}/dhcp6_pd_daemon.py"
+PD_DAEMON_SERVICE_NAME="dhcp6_pd_daemon.service"
+PD_DAEMON_SERVICE="/etc/systemd/system/${PD_DAEMON_SERVICE_NAME}"
+
+create_custom_dhcpcd_conf()
 {
-    # This has to be run after script/_border_routing, and this will
-    # invalidate all changes to dhcpcd.conf made by script/_border_routing.
-    sudo tee /etc/dhcpcd.conf >/dev/null <<EOF
+    sudo tee /etc/dhcpcd.conf.custom >/dev/null <<EOF
 noipv6rs # disable router solicitation
 interface eth0
   iaid 1
@@ -42,16 +48,49 @@ interface eth0
 EOF
 }
 
+create_dhcp6_pd_daemon_service()
+{
+    sudo tee ${PD_DAEMON_SERVICE} <<EOF
+[Unit]
+Description=Daemon call scripts on every PD state change
+After=otbr-agent.service
+ConditionPathExists=${PD_DAEMON}
+
+[Service]
+Type=simple
+User=root
+ExecStart=/usr/bin/python3 ${PD_DAEMON}
+Restart=on-failure
+
+[Install]
+WantedBy=multi-user.target
+EOF
+}
+
 dhcpv6_pd_ref_uninstall()
 {
     with DHCPV6_PD_REF || return 0
 
+    if have systemctl; then
+        sudo systemctl disable ${PD_DAEMON_SERVICE_NAME} || true
+        sudo systemctl stop ${PD_DAEMON_SERVICE_NAME} || true
+        sudo rm -f ${PD_DAEMON_SERVICE} || true
+    fi
+
     if [[ -f "/etc/dhcpcd.conf.orig" ]]; then
         sudo mv /etc/dhcpcd.conf.orig /etc/dhcpcd.conf
     fi
-    sudo systemctl restart dhcpcd
-    sudo rm -f /etc/dhcpcd.enter-hook /etc/dhcpcd.exit-hook
 
+    sudo rm -f ${DHCPCD_ENTER_HOOK} ${DHCPCD_EXIT_HOOK}
+    sudo rm -f ${PD_DAEMON}
+
+    if have systemctl; then
+        sudo systemctl daemon-reload
+
+        if systemctl is-active dhcpcd; then
+            sudo systemctl restart dhcpcd || true
+        fi
+    fi
 }
 
 dhcpv6_pd_ref_install()
@@ -60,9 +99,22 @@ dhcpv6_pd_ref_install()
 
     if [[ -f "/etc/dhcpcd.conf" ]]; then
         sudo mv /etc/dhcpcd.conf /etc/dhcpcd.conf.orig
+    else
+        sudo touch /etc/dhcpcd.conf.orig
     fi
-    customise_dhcpcd_conf
+
     # Add dhcpcd.hooks
-    sudo install -m 755 "$(dirname "$0")"/reference-device/dhcpcd.enter-hook /etc/dhcpcd.enter-hook
-    sudo install -m 755 "$(dirname "$0")"/reference-device/dhcpcd.exit-hook /etc/dhcpcd.exit-hook
+    sudo install -m 755 "$(dirname "$0")"/reference-device/dhcpcd.enter-hook ${DHCPCD_ENTER_HOOK}
+    sudo install -m 755 "$(dirname "$0")"/reference-device/dhcpcd.exit-hook ${DHCPCD_EXIT_HOOK}
+    sudo mkdir -p ${PD_DAEMON_PATH}
+    sudo install -m 755 "$(dirname "$0")"/reference-device/dhcp6_pd_daemon.py ${PD_DAEMON}
+
+    create_custom_dhcpcd_conf
+    create_dhcp6_pd_daemon_service
+
+    if have systemctl; then
+        sudo systemctl daemon-reload
+        sudo systemctl enable ${PD_DAEMON_SERVICE_NAME}
+        sudo systemctl start ${PD_DAEMON_SERVICE_NAME}
+    fi
 }
diff --git a/script/reference-device/dhcp6_pd_daemon.py b/script/reference-device/dhcp6_pd_daemon.py
index 9b486f0315b..113ca574268 100755
--- a/script/reference-device/dhcp6_pd_daemon.py
+++ b/script/reference-device/dhcp6_pd_daemon.py
@@ -31,6 +31,7 @@
 import dbus
 import gi.repository.GLib as GLib
 import subprocess
+import threading
 import os
 
 from dbus.mainloop.glib import DBusGMainLoop
@@ -41,30 +42,48 @@
 bus = dbus.SystemBus()
 thread_dbus_obj = None
 iface = None
-backup_dir = "/var/lib/ot-dhcpcd-backup"
+intended_dhcp6pd_state = None
+
+def restart_dhcpcd_with_custom_config():
+    global intended_dhcp6pd_state
+    if os.path.isfile("/etc/dhcpcd.conf.custom"):
+        try:
+            subprocess.run(["sudo", "cp", "/etc/dhcpcd.conf.custom", "/etc/dhcpcd.conf"], check=True)
+            subprocess.run(["sudo", "systemctl", "daemon-reload"], check=True)
+            subprocess.run(["sudo", "service", "dhcpcd", "restart"], check=True)
+            logging.info("Successfully restarted dhcpcd service.")
+            intended_dhcp6pd_state = None
+        except subprocess.CalledProcessError as e:
+            logging.error(f"Error restarting dhcpcd service: {e}")
+            intended_dhcp6pd_state = None
+    else:
+        logging.error("Customised configuration file not found. Cannot apply custom.")
+        intended_dhcp6pd_state = None
+
+def restore_default_config():
+    if os.path.isfile("/etc/dhcpcd.conf.orig"):
+        try:
+            subprocess.run(["sudo", "cp", "/etc/dhcpcd.conf.orig", "/etc/dhcpcd.conf"], check=True)
+            subprocess.run(["sudo", "systemctl", "daemon-reload"], check=True)
+            subprocess.run(["sudo", "service", "dhcpcd", "restart"], check=True)
+            logging.info("Successfully restored default dhcpcd config.")
+        except subprocess.CalledProcessError as e:
+            logging.error(f"Error restoring dhcpcd config: {e}")
+    else:
+        logging.error("Backup configuration file not found. Cannot restore default.")
 
 def properties_changed_handler(interface_name, changed_properties, invalidated_properties):
+    global intended_dhcp6pd_state
     if "Dhcp6PdState" in changed_properties:
         new_state = changed_properties["Dhcp6PdState"]
-        logging.info(f"Dhcp6PdState changed to: {new_state}")
-        if new_state == "running":
-            os.makedirs(backup_dir, exist_ok=True)
-            subprocess.run(["sudo", "cp", "/etc/dhcpcd.conf", f"{backup_dir}/dhcpcd.conf.orig"], check=True)
-            try:
-                subprocess.run(["sudo", "systemctl", "daemon-reload"], check=True)
-                subprocess.run(["sudo", "service", "dhcpcd", "restart"], check=True)
-                logging.info("Successfully restarted dhcpcd service.")
-            except subprocess.CalledProcessError as e:
-                logging.error(f"Error restarting dhcpcd service: {e}")
-        elif new_state == "stopped":
-            if os.path.isfile(f"{backup_dir}/dhcpcd.conf.orig"):
-                try:
-                    subprocess.run(["sudo", "cp", f"{backup_dir}/dhcpcd.conf.orig", "/etc/dhcpcd.conf"], check=True)
-                    logging.info("Successfully restored default dhcpcd config.")
-                except subprocess.CalledProcessError as e:
-                    logging.error(f"Error restoring dhcpcd config: {e}")
-            else:
-                logging.error("Backup configuration file not found. Cannot restore default.")
+        if new_state == "running" and intended_dhcp6pd_state != "running":
+            logging.info(f"Dhcp6PdState changed to: {new_state}")
+            intended_dhcp6pd_state = "running"
+            thread = threading.Thread(target=restart_dhcpcd_with_custom_config)
+            thread.start()
+        elif new_state in ("stopped", "disabled") and intended_dhcp6pd_state is None:
+            logging.info(f"Dhcp6PdState changed to: {new_state}")
+            restore_default_config()
 
 def connect_to_signal():
     global thread_dbus_obj, thread_properties_dbus_iface