feat(healthcheck): HEALTH_ICMP_TARGET_IP -> HEALTH_ICMP_TARGET_IPS

- Specify fallback ICMP IP addresses
- Defaults changed from 1.1.1.1 to 1.1.1.1,8.8.8.8
- Small periodic check cycles through addresses as it fails and moves to retry
This commit is contained in:
Quentin McGaw
2025-11-19 16:00:20 +00:00
parent f9490656eb
commit 9f39d47150
6 changed files with 60 additions and 33 deletions

View File

@@ -164,7 +164,7 @@ ENV VPN_SERVICE_PROVIDER=pia \
# Health
HEALTH_SERVER_ADDRESS=127.0.0.1:9999 \
HEALTH_TARGET_ADDRESSES=cloudflare.com:443,github.com:443 \
HEALTH_ICMP_TARGET_IP=1.1.1.1 \
HEALTH_ICMP_TARGET_IPS=1.1.1.1,8.8.8.8 \
HEALTH_RESTART_VPN=on \
# DNS
DNS_SERVER=on \

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@@ -1,6 +1,7 @@
package settings
import (
"errors"
"fmt"
"net/netip"
"os"
@@ -22,22 +23,38 @@ type Health struct {
// Addresses after the first one are used as fallbacks for retries.
// It cannot be empty in the internal state.
TargetAddresses []string
// ICMPTargetIP is the IP address to use for ICMP echo requests
// in the health checker. It can be set to an unspecified address (0.0.0.0)
// such that the VPN server IP is used, although this can be less reliable.
// It defaults to 1.1.1.1, and cannot be left empty (invalid) in the internal state.
ICMPTargetIP netip.Addr
// ICMPTargetIPs are the IP addresses to use for ICMP echo requests
// in the health checker. The slice can be set to a single
// unspecified address (0.0.0.0) such that the VPN server IP is used,
// although this can be less reliable. It defaults to [1.1.1.1,8.8.8.8],
// and cannot be left empty in the internal state.
ICMPTargetIPs []netip.Addr
// RestartVPN indicates whether to restart the VPN connection
// when the healthcheck fails.
RestartVPN *bool
}
var (
ErrICMPTargetIPNotValid = errors.New("ICMP target IP address is not valid")
ErrICMPTargetIPsNotCompatible = errors.New("ICMP target IP addresses are not compatible")
)
func (h Health) Validate() (err error) {
err = validate.ListeningAddress(h.ServerAddress, os.Getuid())
if err != nil {
return fmt.Errorf("server listening address is not valid: %w", err)
}
for _, ip := range h.ICMPTargetIPs {
switch {
case !ip.IsValid():
return fmt.Errorf("%w: %s", ErrICMPTargetIPNotValid, ip)
case ip.IsUnspecified() && len(h.ICMPTargetIPs) > 1:
return fmt.Errorf("%w: only a single IP address must be set if it is to be unspecified",
ErrICMPTargetIPsNotCompatible)
}
}
return nil
}
@@ -45,7 +62,7 @@ func (h *Health) copy() (copied Health) {
return Health{
ServerAddress: h.ServerAddress,
TargetAddresses: h.TargetAddresses,
ICMPTargetIP: h.ICMPTargetIP,
ICMPTargetIPs: gosettings.CopySlice(h.ICMPTargetIPs),
RestartVPN: gosettings.CopyPointer(h.RestartVPN),
}
}
@@ -56,14 +73,17 @@ func (h *Health) copy() (copied Health) {
func (h *Health) OverrideWith(other Health) {
h.ServerAddress = gosettings.OverrideWithComparable(h.ServerAddress, other.ServerAddress)
h.TargetAddresses = gosettings.OverrideWithSlice(h.TargetAddresses, other.TargetAddresses)
h.ICMPTargetIP = gosettings.OverrideWithComparable(h.ICMPTargetIP, other.ICMPTargetIP)
h.ICMPTargetIPs = gosettings.OverrideWithSlice(h.ICMPTargetIPs, other.ICMPTargetIPs)
h.RestartVPN = gosettings.OverrideWithPointer(h.RestartVPN, other.RestartVPN)
}
func (h *Health) SetDefaults() {
h.ServerAddress = gosettings.DefaultComparable(h.ServerAddress, "127.0.0.1:9999")
h.TargetAddresses = gosettings.DefaultSlice(h.TargetAddresses, []string{"cloudflare.com:443", "github.com:443"})
h.ICMPTargetIP = gosettings.DefaultComparable(h.ICMPTargetIP, netip.AddrFrom4([4]byte{1, 1, 1, 1}))
h.ICMPTargetIPs = gosettings.DefaultSlice(h.ICMPTargetIPs, []netip.Addr{
netip.AddrFrom4([4]byte{1, 1, 1, 1}),
netip.AddrFrom4([4]byte{8, 8, 8, 8}),
})
h.RestartVPN = gosettings.DefaultPointer(h.RestartVPN, true)
}
@@ -78,11 +98,14 @@ func (h Health) toLinesNode() (node *gotree.Node) {
for _, targetAddr := range h.TargetAddresses {
targetAddrs.Append(targetAddr)
}
icmpTarget := "VPN server IP"
if !h.ICMPTargetIP.IsUnspecified() {
icmpTarget = h.ICMPTargetIP.String()
if len(h.ICMPTargetIPs) == 1 && h.ICMPTargetIPs[0].IsUnspecified() {
node.Appendf("ICMP target IP: VPN server IP address")
} else {
icmpIPs := node.Appendf("ICMP target IPs:")
for _, ip := range h.ICMPTargetIPs {
icmpIPs.Append(ip.String())
}
}
node.Appendf("ICMP target IP: %s", icmpTarget)
node.Appendf("Restart VPN on healthcheck failure: %s", gosettings.BoolToYesNo(h.RestartVPN))
return node
}
@@ -91,7 +114,7 @@ func (h *Health) Read(r *reader.Reader) (err error) {
h.ServerAddress = r.String("HEALTH_SERVER_ADDRESS")
h.TargetAddresses = r.CSV("HEALTH_TARGET_ADDRESSES",
reader.RetroKeys("HEALTH_ADDRESS_TO_PING", "HEALTH_TARGET_ADDRESS"))
h.ICMPTargetIP, err = r.NetipAddr("HEALTH_ICMP_TARGET_IP")
h.ICMPTargetIPs, err = r.CSVNetipAddresses("HEALTH_ICMP_TARGET_IPS", reader.RetroKeys("HEALTH_ICMP_TARGET_IP"))
if err != nil {
return err
}

View File

@@ -60,7 +60,9 @@ func Test_Settings_String(t *testing.T) {
| ├── Target addresses:
| | ├── cloudflare.com:443
| | └── github.com:443
| ├── ICMP target IP: 1.1.1.1
| ├── ICMP target IPs:
| | ├── 1.1.1.1
| | └── 8.8.8.8
| └── Restart VPN on healthcheck failure: yes
├── Shadowsocks server settings:
| └── Enabled: no

View File

@@ -16,13 +16,13 @@ import (
)
type Checker struct {
tlsDialAddrs []string
dialer *net.Dialer
echoer *icmp.Echoer
dnsClient *dns.Client
logger Logger
icmpTarget netip.Addr
configMutex sync.Mutex
tlsDialAddrs []string
dialer *net.Dialer
echoer *icmp.Echoer
dnsClient *dns.Client
logger Logger
icmpTargetIPs []netip.Addr
configMutex sync.Mutex
icmpNotPermitted bool
smallCheckName string
@@ -48,11 +48,11 @@ func NewChecker(logger Logger) *Checker {
// SetConfig sets the TCP+TLS dial addresses and the ICMP echo IP address
// to target by the [Checker].
// This function MUST be called before calling [Checker.Start].
func (c *Checker) SetConfig(tlsDialAddrs []string, icmpTarget netip.Addr) {
func (c *Checker) SetConfig(tlsDialAddrs []string, icmpTargets []netip.Addr) {
c.configMutex.Lock()
defer c.configMutex.Unlock()
c.tlsDialAddrs = tlsDialAddrs
c.icmpTarget = icmpTarget
c.icmpTargetIPs = icmpTargets
}
// Start starts the checker by first running a blocking 6s-timed TCP+TLS check,
@@ -63,7 +63,7 @@ func (c *Checker) SetConfig(tlsDialAddrs []string, icmpTarget netip.Addr) {
// It returns an error if the initial TCP+TLS check fails.
// The Checker has to be ultimately stopped by calling [Checker.Stop].
func (c *Checker) Start(ctx context.Context) (runError <-chan error, err error) {
if len(c.tlsDialAddrs) == 0 || c.icmpTarget.IsUnspecified() {
if len(c.tlsDialAddrs) == 0 || len(c.icmpTargetIPs) == 0 {
panic("call Checker.SetConfig with non empty values before Checker.Start")
}
@@ -118,13 +118,14 @@ func (c *Checker) Stop() error {
c.stop()
<-c.done
c.tlsDialAddrs = nil
c.icmpTarget = netip.Addr{}
c.icmpTargetIPs = nil
return nil
}
func (c *Checker) smallPeriodicCheck(ctx context.Context) error {
c.configMutex.Lock()
ip := c.icmpTarget
icmpTargetIPs := make([]netip.Addr, len(c.icmpTargetIPs))
copy(icmpTargetIPs, c.icmpTargetIPs)
c.configMutex.Unlock()
tryTimeouts := []time.Duration{
5 * time.Second,
@@ -138,10 +139,11 @@ func (c *Checker) smallPeriodicCheck(ctx context.Context) error {
15 * time.Second,
30 * time.Second,
}
check := func(ctx context.Context, _ int) error {
check := func(ctx context.Context, try int) error {
if c.icmpNotPermitted {
return c.dnsClient.Check(ctx)
}
ip := icmpTargetIPs[try%len(icmpTargetIPs)]
err := c.echoer.Echo(ctx, ip)
if errors.Is(err, icmp.ErrNotPermitted) {
c.icmpNotPermitted = true

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@@ -101,7 +101,7 @@ type CmdStarter interface {
}
type HealthChecker interface {
SetConfig(tlsDialAddrs []string, icmpTarget netip.Addr)
SetConfig(tlsDialAddrs []string, icmpTargetIPs []netip.Addr)
Start(ctx context.Context) (runError <-chan error, err error)
Stop() error
}

View File

@@ -31,11 +31,11 @@ func (l *Loop) onTunnelUp(ctx, loopCtx context.Context, data tunnelUpData) {
}
}
icmpTarget := l.healthSettings.ICMPTargetIP
if icmpTarget.IsUnspecified() {
icmpTarget = data.serverIP
icmpTargetIPs := l.healthSettings.ICMPTargetIPs
if len(icmpTargetIPs) == 1 && icmpTargetIPs[0].IsUnspecified() {
icmpTargetIPs = []netip.Addr{data.serverIP}
}
l.healthChecker.SetConfig(l.healthSettings.TargetAddresses, icmpTarget)
l.healthChecker.SetConfig(l.healthSettings.TargetAddresses, icmpTargetIPs)
healthErrCh, err := l.healthChecker.Start(ctx)
l.healthServer.SetError(err)