From 926fcf202a3bf32545834c5cdd978bc22d698b25 Mon Sep 17 00:00:00 2001
From: Marc Brooks <IDisposable@gmail.com>
Date: Wed, 18 Jun 2025 20:27:36 -0500
Subject: [PATCH] Add support for using DHCP-provided NTP server
---
internal/confparser/confparser_test.go | 4 +--
internal/network/config.go | 6 ++--
internal/network/netif.go | 44 +++++++++++++++++++++++++-
internal/timesync/timesync.go | 36 ++++++++++++++-------
network.go | 8 +++++
5 files changed, 81 insertions(+), 17 deletions(-)
diff --git a/internal/confparser/confparser_test.go b/internal/confparser/confparser_test.go
index 166cdd7..e14a1ea 100644
--- a/internal/confparser/confparser_test.go
+++ b/internal/confparser/confparser_test.go
@@ -46,8 +46,8 @@ type testNetworkConfig struct {
TimeSyncOrdering []string `json:"time_sync_ordering,omitempty" one_of:"http,ntp,ntp_dhcp,ntp_user_provided,http_user_provided" default:"ntp,http"`
TimeSyncDisableFallback null.Bool `json:"time_sync_disable_fallback,omitempty" default:"false"`
TimeSyncParallel null.Int `json:"time_sync_parallel,omitempty" default:"4"`
- TimeSyncNTPServers []string `json:"time_sync_ntp_servers,omitempty" validate_type:"ipv4_or_ipv6" required_if:"TimeSyncOrdering=ntp_custom"`
- TimeSyncHTTPUrls []string `json:"time_sync_http_urls,omitempty" validate_type:"url" required_if:"TimeSyncOrdering=http_custom"`
+ TimeSyncNTPServers []string `json:"time_sync_ntp_servers,omitempty" validate_type:"ipv4_or_ipv6" required_if:"TimeSyncOrdering=ntp_user_provided"`
+ TimeSyncHTTPUrls []string `json:"time_sync_http_urls,omitempty" validate_type:"url" required_if:"TimeSyncOrdering=http_user_provided"`
}
func TestValidateConfig(t *testing.T) {
diff --git a/internal/network/config.go b/internal/network/config.go
index 34d412e..c8fe582 100644
--- a/internal/network/config.go
+++ b/internal/network/config.go
@@ -45,11 +45,11 @@ type NetworkConfig struct {
LLDPTxTLVs []string `json:"lldp_tx_tlvs,omitempty" one_of:"chassis,port,system,vlan" default:"chassis,port,system,vlan"`
MDNSMode null.String `json:"mdns_mode,omitempty" one_of:"disabled,auto,ipv4_only,ipv6_only" default:"auto"`
TimeSyncMode null.String `json:"time_sync_mode,omitempty" one_of:"ntp_only,ntp_and_http,http_only,custom" default:"ntp_and_http"`
- TimeSyncOrdering []string `json:"time_sync_ordering,omitempty" one_of:"http,ntp,ntp_dhcp,ntp_custom,http_custom" default:"ntp,http"`
+ TimeSyncOrdering []string `json:"time_sync_ordering,omitempty" one_of:"http,ntp,ntp_dhcp,ntp_user_provided,http_user_provided" default:"ntp,http"`
TimeSyncDisableFallback null.Bool `json:"time_sync_disable_fallback,omitempty" default:"false"`
TimeSyncParallel null.Int `json:"time_sync_parallel,omitempty" default:"4"`
- TimeSyncNTPServers []string `json:"time_sync_ntp_servers,omitempty" validate_type:"ipv4_or_ipv6" required_if:"TimeSyncOrdering=ntp_custom"`
- TimeSyncHTTPUrls []string `json:"time_sync_http_urls,omitempty" validate_type:"url" required_if:"TimeSyncOrdering=http_custom"`
+ TimeSyncNTPServers []string `json:"time_sync_ntp_servers,omitempty" validate_type:"ipv4_or_ipv6" required_if:"TimeSyncOrdering=ntp_user_provided"`
+ TimeSyncHTTPUrls []string `json:"time_sync_http_urls,omitempty" validate_type:"url" required_if:"TimeSyncOrdering=http_user_provided"`
}
func (c *NetworkConfig) GetMDNSMode() *mdns.MDNSListenOptions {
diff --git a/internal/network/netif.go b/internal/network/netif.go
index c5db806..5a8dab6 100644
--- a/internal/network/netif.go
+++ b/internal/network/netif.go
@@ -21,6 +21,7 @@ type NetworkInterfaceState struct {
ipv6Addr *net.IP
ipv6Addresses []IPv6Address
ipv6LinkLocal *net.IP
+ ntpAddresses []*net.IP
macAddr *net.HardwareAddr
l *zerolog.Logger
@@ -76,6 +77,7 @@ func NewNetworkInterfaceState(opts *NetworkInterfaceOptions) (*NetworkInterfaceS
onInitialCheck: opts.OnInitialCheck,
cbConfigChange: opts.OnConfigChange,
config: opts.NetworkConfig,
+ ntpAddresses: make([]*net.IP, 0),
}
// create the dhcp client
@@ -89,7 +91,7 @@ func NewNetworkInterfaceState(opts *NetworkInterfaceOptions) (*NetworkInterfaceS
opts.Logger.Error().Err(err).Msg("failed to update network state")
return
}
-
+ _ = s.updateNtpServersFromLease(lease)
_ = s.setHostnameIfNotSame()
opts.OnDhcpLeaseChange(lease)
@@ -135,6 +137,27 @@ func (s *NetworkInterfaceState) IPv6String() string {
return s.ipv6Addr.String()
}
+func (s *NetworkInterfaceState) NtpAddresses() []*net.IP {
+ return s.ntpAddresses
+}
+
+func (s *NetworkInterfaceState) NtpAddressesString() []string {
+ ntpServers := []string{}
+
+ if s != nil {
+ s.l.Debug().Any("s", s).Msg("getting NTP address strings")
+
+ if len(s.ntpAddresses) > 0 {
+ for _, server := range s.ntpAddresses {
+ s.l.Debug().IPAddr("server", *server).Msg("converting NTP address")
+ ntpServers = append(ntpServers, server.String())
+ }
+ }
+ }
+
+ return ntpServers
+}
+
func (s *NetworkInterfaceState) MAC() *net.HardwareAddr {
return s.macAddr
}
@@ -318,6 +341,25 @@ func (s *NetworkInterfaceState) update() (DhcpTargetState, error) {
return dhcpTargetState, nil
}
+func (s *NetworkInterfaceState) updateNtpServersFromLease(lease *udhcpc.Lease) error {
+ if lease != nil && len(lease.NTPServers) > 0 {
+ s.l.Info().Msg("lease found, updating DHCP NTP addresses")
+ s.ntpAddresses = make([]*net.IP, 0, len(lease.NTPServers))
+
+ for _, ntpServer := range lease.NTPServers {
+ if ntpServer != nil {
+ s.l.Info().IPAddr("ntp_server", ntpServer).Msg("NTP server found in lease")
+ s.ntpAddresses = append(s.ntpAddresses, &ntpServer)
+ }
+ }
+ } else {
+ s.l.Info().Msg("no NTP servers found in lease")
+ s.ntpAddresses = make([]*net.IP, 0, len(s.config.TimeSyncNTPServers))
+ }
+
+ return nil
+}
+
func (s *NetworkInterfaceState) CheckAndUpdateDhcp() error {
dhcpTargetState, err := s.update()
if err != nil {
diff --git a/internal/timesync/timesync.go b/internal/timesync/timesync.go
index 64bfcd1..db1c96e 100644
--- a/internal/timesync/timesync.go
+++ b/internal/timesync/timesync.go
@@ -28,7 +28,8 @@ type TimeSync struct {
syncLock *sync.Mutex
l *zerolog.Logger
- networkConfig *network.NetworkConfig
+ networkConfig *network.NetworkConfig
+ dhcpNtpAddresses []string
rtcDevicePath string
rtcDevice *os.File //nolint:unused
@@ -62,12 +63,13 @@ func NewTimeSync(opts *TimeSyncOptions) *TimeSync {
}
t := &TimeSync{
- syncLock: &sync.Mutex{},
- l: opts.Logger,
- rtcDevicePath: rtcDevice,
- rtcLock: &sync.Mutex{},
- preCheckFunc: opts.PreCheckFunc,
- networkConfig: opts.NetworkConfig,
+ syncLock: &sync.Mutex{},
+ l: opts.Logger,
+ dhcpNtpAddresses: []string{},
+ rtcDevicePath: rtcDevice,
+ rtcLock: &sync.Mutex{},
+ preCheckFunc: opts.PreCheckFunc,
+ networkConfig: opts.NetworkConfig,
}
if t.rtcDevicePath != "" {
@@ -78,11 +80,15 @@ func NewTimeSync(opts *TimeSyncOptions) *TimeSync {
return t
}
+func (t *TimeSync) SetDhcpNtpAddresses(addresses []string) {
+ t.dhcpNtpAddresses = addresses
+}
+
func (t *TimeSync) getSyncMode() SyncMode {
syncMode := SyncMode{
Ntp: true,
Http: true,
- Ordering: []string{"ntp_dhcp", "ntp_fallback", "http_fallback"},
+ Ordering: []string{"ntp_dhcp", "ntp", "http"},
NtpUseFallback: true,
HttpUseFallback: true,
}
@@ -161,7 +167,7 @@ func (t *TimeSync) Sync() error {
Orders:
for _, mode := range syncMode.Ordering {
switch mode {
- case "ntp_custom":
+ case "ntp_user_provided":
if syncMode.Ntp {
t.l.Info().Msg("using NTP custom servers")
now, offset = t.queryNetworkTime(t.networkConfig.TimeSyncNTPServers)
@@ -170,7 +176,15 @@ Orders:
break Orders
}
}
- case "ntp_fallback":
+ case "ntp_dhcp":
+ if syncMode.Ntp {
+ t.l.Info().Msg("using NTP servers from DHCP")
+ now, offset = t.queryNetworkTime(t.dhcpNtpAddresses)
+ if now != nil {
+ t.l.Info().Str("source", "NTP DHCP").Time("now", *now).Msg("time obtained")
+ break Orders
+ }
+ }
case "ntp":
if syncMode.Ntp && syncMode.NtpUseFallback {
t.l.Info().Msg("using NTP fallback")
@@ -180,7 +194,7 @@ Orders:
break Orders
}
}
- case "http_custom":
+ case "http_user_provided":
if syncMode.Http {
t.l.Info().Msg("using HTTP custom URLs")
now = t.queryAllHttpTime(t.networkConfig.TimeSyncHTTPUrls)
diff --git a/network.go b/network.go
index 2208a47..211b860 100644
--- a/network.go
+++ b/network.go
@@ -19,6 +19,14 @@ func networkStateChanged() {
// do not block the main thread
go waitCtrlAndRequestDisplayUpdate(true)
+ if timeSync != nil {
+ if networkState != nil {
+ timeSync.SetDhcpNtpAddresses(networkState.NtpAddressesString())
+ }
+
+ timeSync.Sync()
+ }
+
// always restart mDNS when the network state changes
if mDNS != nil {
_ = mDNS.SetListenOptions(config.NetworkConfig.GetMDNSMode())