From 558ca760a90eb4f558216c7992c70e18bedb36ca 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                      | 71 ++++++++++++++---
 script/reference-device/dhcp6_pd_daemon.py | 91 ++++++++++++++--------
 script/reference-device/dhcpcd.enter-hook  | 13 +++-
 script/reference-device/dhcpcd.exit-hook   | 10 ++-
 4 files changed, 139 insertions(+), 46 deletions(-)

diff --git a/script/_dhcpv6_pd_ref b/script/_dhcpv6_pd_ref
index b431ce625da..9f03afc7513 100644
--- a/script/_dhcpv6_pd_ref
+++ b/script/_dhcpv6_pd_ref
@@ -30,15 +30,41 @@
 #       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_DIR="/opt/pd-daemon"
+PD_DAEMON_PATH="${PD_DAEMON_DIR}/dhcp6_pd_daemon.py"
+PD_DAEMON_SERVICE_NAME="dhcp6_pd_daemon.service"
+PD_DAEMON_SERVICE_PATH="/etc/systemd/system/${PD_DAEMON_SERVICE_NAME}"
+
+create_pd_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.pd >/dev/null <<EOF
 noipv6rs # disable router solicitation
 interface eth0
   iaid 1
   ia_pd 2/::/64 -
+noipv6rs
+EOF
+}
+
+create_dhcp6_pd_daemon_service()
+{
+    sudo tee ${PD_DAEMON_SERVICE_PATH} <<EOF
+[Unit]
+Description=Daemon to manage dhcpcd based on otbr-agent's PD state change
+After=multi-user.service
+ConditionPathExists=${PD_DAEMON_PATH}
+
+[Service]
+Type=simple
+User=root
+ExecStart=/usr/bin/python3 ${PD_DAEMON_PATH}
+Restart=on-failure
+
+[Install]
+WantedBy=multi-user.target
 EOF
 }
 
@@ -46,12 +72,26 @@ 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_PATH} || 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_PATH}
+
+    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 +100,22 @@ 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 ${PD_DAEMON_DIR}
+    sudo install -m 755 "$(dirname "$0")"/reference-device/dhcp6_pd_daemon.py ${PD_DAEMON_PATH}
+
+    create_pd_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..b246f96d765 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
@@ -39,55 +40,81 @@
 logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')
 
 bus = dbus.SystemBus()
-thread_dbus_obj = None
-iface = None
-backup_dir = "/var/lib/ot-dhcpcd-backup"
+intended_dhcp6pd_state = None
+
+DHCP_CONFIG_FILE = "/etc/dhcpcd.conf"
+DHCP_CONFIG_PD_FILE = "/etc/dhcpcd.conf.pd"
+DHCP_CONFIG_ORIG_FILE = "/etc/dhcpcd.conf.orig"
+
+def restart_dhcpcd_with_pd_config():
+    global intended_dhcp6pd_state
+    if os.path.isfile(DHCP_CONFIG_PD_FILE):
+        try:
+            subprocess.run(["sudo", "cp", DHCP_CONFIG_PD_FILE, DHCP_CONFIG_FILE], 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(f"{DHCP_CONFIG_PD_FILE} not found. Cannot apply configuration with prefix delegation.")
+        intended_dhcp6pd_state = None
+
+def restore_default_config():
+    if os.path.isfile(DHCP_CONFIG_ORIG_FILE):
+        try:
+            subprocess.run(["sudo", "cp", DHCP_CONFIG_ORIG_FILE, DHCP_CONFIG_FILE], check=True)
+            subprocess.run(["sudo", "systemctl", "daemon-reload"], check=True)
+            subprocess.run(["sudo", "dhcpcd", "--release"], 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(f"{DHCP_CONFIG_ORIG_FILE} not found. Cannot restore default configuration.")
 
 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":
+            intended_dhcp6pd_state = "running"
+            thread = threading.Thread(target=restart_dhcpcd_with_pd_config)
+            thread.start()
+        elif new_state in ("stopped", "disabled") and intended_dhcp6pd_state is None:
+            restore_default_config()
 
 def connect_to_signal():
-    global thread_dbus_obj, thread_properties_dbus_iface
     try:
-        thread_dbus_obj = bus.get_object('io.openthread.BorderRouter.wpan0', '/io/openthread/BorderRouter/wpan0')
-        thread_properties_dbus_iface = dbus.Interface(thread_dbus_obj, 'org.freedesktop.DBus.Properties')
-        thread_dbus_obj.connect_to_signal("PropertiesChanged", properties_changed_handler, dbus_interface=thread_properties_dbus_iface.dbus_interface)
+        dbus_obj = bus.get_object('io.openthread.BorderRouter.wpan0', '/io/openthread/BorderRouter/wpan0')
+        properties_dbus_iface = dbus.Interface(dbus_obj, 'org.freedesktop.DBus.Properties')
+        dbus_obj.connect_to_signal("PropertiesChanged", properties_changed_handler, dbus_interface=properties_dbus_iface.dbus_interface)
         logging.info("Connected to D-Bus signal.")
+        return dbus_obj, properties_dbus_iface
     except dbus.DBusException as e:
         logging.error(f"Error connecting to D-Bus: {e}")
-        thread_dbus_obj = None
-        thread_properties_dbus_iface = None
+        return None, None
 
-def check_and_reconnect():
-    if thread_dbus_obj is None:
-        connect_to_signal()
+def check_and_reconnect(dbus_obj, properties_dbus_iface):
+    if dbus_obj is None:
+        dbus_obj, properties_dbus_iface = connect_to_signal()
 
 def main():
+    # always restart dhcpcd to begin with a previous saved state
+    try:
+        subprocess.run(["sudo", "systemctl", "reload-or-restart", "dhcpcd"], check=True)
+        logging.info("Successfully restarting dhcpcd service.")
+    except subprocess.CalledProcessError as e:
+        logging.error(f"Error restarting dhcpcd service: {e}")
+
     loop = GLib.MainLoop()
 
-    connect_to_signal()
+    thread_dbus_obj, thread_properties_dbus_iface = connect_to_signal()
 
-    GLib.timeout_add_seconds(5, check_and_reconnect)
+    GLib.timeout_add_seconds(5, check_and_reconnect, thread_dbus_obj, thread_properties_dbus_iface) 
 
     loop.run()
 
diff --git a/script/reference-device/dhcpcd.enter-hook b/script/reference-device/dhcpcd.enter-hook
index cfa62800502..b6fb20cde89 100644
--- a/script/reference-device/dhcpcd.enter-hook
+++ b/script/reference-device/dhcpcd.enter-hook
@@ -67,9 +67,16 @@ if [ ${interface} = ${UPSTREAM_INTERFACE} ]; then
 
     case $reason in
         DELEGATED6 | REBIND6 | RENEW6 | BOUND6 )
-            logger "$LOG_TAG prefix is $new_dhcp6_ia_pd1_prefix1  length is $new_dhcp6_ia_pd1_prefix1_length pltime is  $new_dhcp6_ia_pd1_prefix1_pltime vltime is $new_dhcp6_ia_pd1_prefix1_vltime"
-            config_ra $new_dhcp6_ia_pd1_prefix1 $new_dhcp6_ia_pd1_prefix1_length $new_dhcp6_ia_pd1_prefix1_pltime  $new_dhcp6_ia_pd1_prefix1_vltime
-            sudo systemctl reload radvd || logger "$LOG_TAG Failed to reload radvd"
+            if [ -z "$new_dhcp6_ia_pd1_prefix1" ] || [ -z "$new_dhcp6_ia_pd1_prefix1_length" ] || \
+               [ -z "$new_dhcp6_ia_pd1_prefix1_pltime" ] || [ -z "$new_dhcp6_ia_pd1_prefix1_vltime" ]; then
+                logger "$LOG_TAG WARNING: Missing DHCPv6 prefix information. Skipping radvd configuration."
+            else
+                logger "$LOG_TAG prefix is $new_dhcp6_ia_pd1_prefix1  length is $new_dhcp6_ia_pd1_prefix1_length pltime is  $new_dhcp6_ia_pd1_prefix1_pltime vltime is $new_dhcp6_ia_pd1_prefix1_vltime"
+                config_ra $new_dhcp6_ia_pd1_prefix1 $new_dhcp6_ia_pd1_prefix1_length $new_dhcp6_ia_pd1_prefix1_pltime  $new_dhcp6_ia_pd1_prefix1_vltime
+                if systemctl is-active network.target; then
+                    sudo systemctl reload-or-restart radvd || logger "$LOG_TAG Failed to reload radvd"
+                fi
+            fi
             ;;
     esac
 fi
diff --git a/script/reference-device/dhcpcd.exit-hook b/script/reference-device/dhcpcd.exit-hook
index faed780ade0..f4912956096 100644
--- a/script/reference-device/dhcpcd.exit-hook
+++ b/script/reference-device/dhcpcd.exit-hook
@@ -66,8 +66,14 @@ if [ ${interface} = ${UPSTREAM_INTERFACE} ]; then
 
     case $reason in
         EXPIRE6 | STOP6)
-            config_ra $old_dhcp6_ia_pd1_prefix1 $old_dhcp6_ia_pd1_prefix1_length 0 0
-            sudo systemctl reload radvd
+            if [ -z "$old_dhcp6_ia_pd1_prefix1" ] || [ -z "$old_dhcp6_ia_pd1_prefix1_length" ]; then
+                logger "$LOG_TAG WARNING: Missing DHCPv6 prefix information. Skipping radvd configuration."
+            else
+                config_ra $old_dhcp6_ia_pd1_prefix1 $old_dhcp6_ia_pd1_prefix1_length 0 0
+                if systemctl is-active network.target; then
+                    sudo systemctl reload-or-restart radvd
+                fi
+            fi
             ;;
     esac
 fi