[triggers/usb] add UsbDisconnect Trigger

triggers/triggers.go

@@ -30,6 +30,7 @@ func GetAllTriggers() []DocumentedTrigger {
 	return []DocumentedTrigger{
 		TimeOut{},
 		EthernetDisconnect{},
+		UsbDisconnect{},
 	}
 }
 

triggers/usb.go

@@ -0,0 +1,96 @@
+package triggers
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"time"
+
+	"unknown.com/gokill/actions"
+	"unknown.com/gokill/internal"
+)
+
+type UsbDisconnect struct {
+	WaitTillConnected bool   `json:"waitTillConnected"`
+	DeviceName        string `json:"deviceName"`
+	action            actions.Action
+}
+
+func isUsbConnected(deviceName string) bool {
+	devicePath := "/dev/disk/by-id/" + deviceName
+
+	_, err := os.Open(devicePath)
+
+	if errors.Is(err, os.ErrNotExist) {
+		return false
+	}
+
+	return true
+}
+
+func (t UsbDisconnect) Listen() {
+	if t.WaitTillConnected {
+		for !isUsbConnected(t.DeviceName) {
+			time.Sleep(1 * time.Second)
+		}
+
+		fmt.Sprintln("Device %s detected.", t.DeviceName)
+		fmt.Println("UsbDisconnect Trigger is Armed")
+	}
+
+	for {
+		if !isUsbConnected(t.DeviceName) {
+			break
+		}
+
+		time.Sleep(1 * time.Second)
+	}
+
+	actions.Fire(t.action)
+}
+
+func CreateUsbDisconnect(config internal.KillSwitchConfig) (UsbDisconnect, error) {
+	result := UsbDisconnect{
+		WaitTillConnected: true,
+	}
+
+	err := json.Unmarshal(config.Options, &result)
+
+	if err != nil {
+		return UsbDisconnect{}, err
+	}
+
+	if result.DeviceName == "" {
+		return UsbDisconnect{}, internal.OptionMissingError{"deviceName"}
+	}
+
+	action, err := actions.NewAction(config.Actions)
+
+	if err != nil {
+		return UsbDisconnect{}, err
+	}
+
+	result.action = action
+
+	return result, nil
+}
+
+func (e UsbDisconnect) Create(config internal.KillSwitchConfig) (Trigger, error) {
+	return CreateUsbDisconnect(config)
+}
+
+func (p UsbDisconnect) GetName() string {
+	return "UsbDisconnect"
+}
+
+func (p UsbDisconnect) GetDescription() string {
+	return "Triggers when given usb drive is disconnected"
+}
+
+func (p UsbDisconnect) GetOptions() []internal.ConfigOption {
+	return []internal.ConfigOption{
+		{"waitTillConnected", "bool", "Only trigger when device was connected before", "true"},
+		{"deviceId", "string", "Name of device under /dev/disk/by-id/", "\"\""},
+	}
+}