Fix connection monitoring on Windows

Linux requires su for `ip4:icmp` pings. Windows does not support `udp4`
pings.

Signed-off-by: Simon Rozman <simon@rozman.si>

4 files changed, 46 insertions, 13 deletions

diff --git a/internal/failover/monitor.go b/internal/failover/monitor.go
index f143f94..5dcaf5c 100644
--- a/internal/failover/monitor.go
+++ b/internal/failover/monitor.go
@@ -51,7 +51,7 @@ func (m *DroppedConMon) Start(gateway string, mtuSize int) (bool, error) {
 	defer m.cancel()
 
 	// Create a ping struct with our mtu size
-	p, err := NewPinger(mtuSize)
+	p, err := NewPinger(gateway, mtuSize)
 	if err != nil {
 		return false, err
 	}
@@ -64,7 +64,7 @@ func (m *DroppedConMon) Start(gateway string, mtuSize int) (bool, error) {
 
 	// Send a ping and wait for max 2 seconds
 	// If we have then increased Rx bytes we return early
-	if err = p.Send(gateway, 1); err != nil {
+	if err = p.Send(1); err != nil {
 		log.Logger.Debugf("[Failover] First ping failed, exiting...")
 		return false, err
 	}
@@ -90,7 +90,7 @@ func (m *DroppedConMon) Start(gateway string, mtuSize int) (bool, error) {
 	for s := 2; s <= m.pDropped; s++ {
 		log.Logger.Debugf("[Failover] Sending ping: %d, with size: %d", s, mtuSize)
 		// Send a ping and return if an error occurs
-		if err := p.Send(gateway, s); err != nil {
+		if err := p.Send(s); err != nil {
 			log.Logger.Debugf("[Failover] A ping failed, exiting...")
 			return false, err
 		}
diff --git a/internal/failover/ping.go b/internal/failover/ping.go
index 15d4adb..fb1df4e 100644
--- a/internal/failover/ping.go
+++ b/internal/failover/ping.go
@@ -18,14 +18,7 @@ var mtuOverhead = 28
 type Pinger struct {
 	listener net.PacketConn
 	buffer   []byte
-}
-
-func NewPinger(size int) (*Pinger, error) {
-	l, err := icmp.ListenPacket("udp4", "0.0.0.0")
-	if err != nil {
-		return nil, errors.WrapPrefix(err, "failed creating ping", 0)
-	}
-	return &Pinger{listener: l, buffer: make([]byte, size-mtuOverhead)}, nil
+	gateway  net.Addr
 }
 
 func (p Pinger) Read(deadline time.Time) error {
@@ -52,7 +45,7 @@ func (p Pinger) Read(deadline time.Time) error {
 	}
 }
 
-func (p Pinger) Send(gateway string, seq int) error {
+func (p Pinger) Send(seq int) error {
 	errorMessage := fmt.Sprintf("failed sending ping, seq %d", seq)
 	// Make a new ICMP message
 	m := icmp.Message{
@@ -68,7 +61,7 @@ func (p Pinger) Send(gateway string, seq int) error {
 		return errors.WrapPrefix(err, errorMessage, 0)
 	}
 	// And send it to the gateway IP!
-	_, err = p.listener.WriteTo(b, &net.UDPAddr{IP: net.ParseIP(gateway)})
+	_, err = p.listener.WriteTo(b, p.gateway)
 	if err != nil {
 		return errors.WrapPrefix(err, errorMessage, 0)
 	}
diff --git a/internal/failover/ping_default.go b/internal/failover/ping_default.go
new file mode 100644
index 0000000..961c6db
--- /dev/null
+++ b/internal/failover/ping_default.go
@@ -0,0 +1,21 @@
+//go:build !windows
+
+package failover
+
+import (
+	"net"
+
+	"github.com/go-errors/errors"
+	"golang.org/x/net/icmp"
+)
+
+func NewPinger(gateway string, size int) (*Pinger, error) {
+	l, err := icmp.ListenPacket("udp4", "0.0.0.0")
+	if err != nil {
+		return nil, errors.WrapPrefix(err, "failed creating ping", 0)
+	}
+	return &Pinger{
+		listener: l,
+		buffer:   make([]byte, size-mtuOverhead),
+		gateway:  &net.UDPAddr{IP: net.ParseIP(gateway)}}, nil
+}
diff --git a/internal/failover/ping_windows.go b/internal/failover/ping_windows.go
new file mode 100644
index 0000000..2a39003
--- /dev/null
+++ b/internal/failover/ping_windows.go
@@ -0,0 +1,19 @@
+package failover
+
+import (
+	"net"
+
+	"github.com/go-errors/errors"
+	"golang.org/x/net/icmp"
+)
+
+func NewPinger(gateway string, size int) (*Pinger, error) {
+	l, err := icmp.ListenPacket("ip4:icmp", "0.0.0.0")
+	if err != nil {
+		return nil, errors.WrapPrefix(err, "failed creating ping", 0)
+	}
+	return &Pinger{
+		listener: l,
+		buffer:   make([]byte, size-mtuOverhead),
+		gateway:  &net.IPAddr{IP: net.ParseIP(gateway)}}, nil
+}