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-rw-r--r--gui/backend.go342
1 files changed, 342 insertions, 0 deletions
diff --git a/gui/backend.go b/gui/backend.go
new file mode 100644
index 0000000..9a952a7
--- /dev/null
+++ b/gui/backend.go
@@ -0,0 +1,342 @@
+package main
+
+/* a wrapper around bitmask that exposes status to a QtQml gui */
+
+import (
+ "bytes"
+ "encoding/json"
+ "fmt"
+ "log"
+ "net/http"
+ "os"
+ "reflect"
+ "sync"
+ "unsafe"
+
+ "0xacab.org/leap/bitmask-vpn/pkg/bitmask"
+ "github.com/jmshal/go-locale"
+ "github.com/kalikaneko/bitmask-vpn/pkg/systray2"
+ "golang.org/x/text/message"
+)
+
+// typedef void (*cb)();
+// inline void _do_callback(cb f) {
+// f();
+// }
+import "C"
+
+/* callbacks into C-land */
+
+var mut sync.Mutex
+var stmut sync.Mutex
+var cbs = make(map[string](*[0]byte))
+var initOnce sync.Once
+
+// Events are just a enumeration of all the posible events that C functions can
+// be interested in subscribing to. You cannot subscribe to an event that is
+// not listed here.
+type Events struct {
+ OnStatusChanged string
+}
+
+const OnStatusChanged string = "OnStatusChanged"
+
+// subscribe registers a callback from C-land.
+// This callback needs to be passed as a void* C function pointer.
+func subscribe(event string, fp unsafe.Pointer) {
+ mut.Lock()
+ defer mut.Unlock()
+ e := &Events{}
+ v := reflect.Indirect(reflect.ValueOf(&e))
+ hf := v.Elem().FieldByName(event)
+ if reflect.ValueOf(hf).IsZero() {
+ fmt.Println("ERROR: not a valid event:", event)
+ } else {
+ cbs[event] = (*[0]byte)(fp)
+ }
+}
+
+// trigger fires a callback from C-land.
+func trigger(event string) {
+ mut.Lock()
+ defer mut.Unlock()
+ cb := cbs[event]
+ if cb != nil {
+ C._do_callback(cb)
+ } else {
+ fmt.Println("ERROR: this event does not have subscribers:", event)
+ }
+}
+
+/* connection status */
+
+const logFile = "systray.log"
+
+const (
+ offStr = "off"
+ startingStr = "starting"
+ onStr = "on"
+ stoppingStr = "stopping"
+ failedStr = "failed"
+)
+
+// status reflects the current VPN status. Go code is responsible for updating
+// it; C-land just watches its changes and pulls its updates via the serialized
+// context object.
+type status int
+
+const (
+ off status = iota
+ starting
+ on
+ stopping
+ failed
+ unknown
+)
+
+func (s status) String() string {
+ return [...]string{offStr, startingStr, onStr, stoppingStr, failedStr}[s]
+}
+
+func (s status) MarshalJSON() ([]byte, error) {
+ b := bytes.NewBufferString(`"`)
+ b.WriteString(s.String())
+ b.WriteString(`"`)
+ return b.Bytes(), nil
+}
+
+func (s status) fromString(st string) status {
+ switch st {
+ case offStr:
+ return off
+ case startingStr:
+ return starting
+ case onStr:
+ return on
+ case stoppingStr:
+ return stopping
+ case failedStr:
+ return failed
+ default:
+ return unknown
+ }
+}
+
+// An action is originated in the UI. These represent requests coming from the
+// frontend via the C code. VPN code needs to watch them and fullfill their
+// requests as soon as possible.
+type actions int
+
+const (
+ switchOn actions = iota
+ switchOff
+ unblock
+)
+
+func (a actions) String() string {
+ return [...]string{"switchOn", "switchOff", "unblock"}[a]
+}
+
+func (a actions) MarshalJSON() ([]byte, error) {
+ b := bytes.NewBufferString(`"`)
+ b.WriteString(a.String())
+ b.WriteString(`"`)
+ return b.Bytes(), nil
+}
+
+// The connectionCtx keeps the global state that is passed around to C-land. It
+// also serves as the primary way of passing requests from the frontend to the
+// Go-core, by letting the UI write some of these variables and processing
+// them.
+type connectionCtx struct {
+ AppName string `json:"appName"`
+ Provider string `json:"provider"`
+ Status status `json:"status"`
+ Actions []actions `json:"actions,omitempty"`
+ bm bitmask.Bitmask
+}
+
+func (c connectionCtx) toJson() ([]byte, error) {
+ stmut.Lock()
+ defer stmut.Unlock()
+ b, err := json.Marshal(c)
+ if err != nil {
+ log.Println(err)
+ return nil, err
+ }
+ return b, nil
+}
+
+func (c connectionCtx) updateStatus() {
+ if stStr, err := c.bm.GetStatus(); err != nil {
+ log.Printf("Error getting status: %v", err)
+ } else {
+ setStatusFromStr(stStr)
+ }
+
+ statusCh := c.bm.GetStatusCh()
+ for {
+ select {
+ case stStr := <-statusCh:
+ setStatusFromStr(stStr)
+ }
+ }
+}
+
+var ctx *connectionCtx
+
+func setStatus(st status) {
+ stmut.Lock()
+ defer stmut.Unlock()
+ ctx.Status = st
+ go trigger(OnStatusChanged)
+}
+
+func setStatusFromStr(stStr string) {
+ log.Println("status:", stStr)
+ setStatus(unknown.fromString(stStr))
+}
+
+func initPrinter() *message.Printer {
+ locale, err := go_locale.DetectLocale()
+ if err != nil {
+ log.Println("Error detecting the system locale: ", err)
+ }
+
+ return message.NewPrinter(message.MatchLanguage(locale, "en"))
+}
+
+// initializeBitmask instantiates a bitmask connection
+func initializeBitmask() {
+ if ctx == nil {
+ log.Println("error: cannot initialize bitmask, ctx is nil")
+ os.Exit(1)
+ }
+ conf := systray.ParseConfig()
+ conf.Version = "unknown"
+ conf.Printer = initPrinter()
+ b, err := bitmask.Init(conf.Printer)
+ if err != nil {
+ log.Fatal(err)
+ }
+ ctx.bm = b
+}
+
+func startVPN() {
+ err := ctx.bm.StartVPN(ctx.Provider)
+ if err != nil {
+ log.Println(err)
+ os.Exit(1)
+ }
+}
+
+func stopVPN() {
+ err := ctx.bm.StopVPN()
+ if err != nil {
+ log.Println(err)
+ }
+}
+
+// initializeContext initializes an empty connStatus and assigns it to the
+// global ctx holder. This is expected to be called only once, so the public
+// api uses the sync.Once primitive to call this.
+func initializeContext(provider, appName string) {
+ var st status = off
+ ctx = &connectionCtx{
+ AppName: appName,
+ Provider: provider,
+ Status: st,
+ }
+ go trigger(OnStatusChanged)
+ initializeBitmask()
+}
+
+/* mock http server: easy way to mocking vpn behavior on ui interaction. This
+* should also show a good way of writing functionality tests just for the Qml
+* layer */
+
+func mockUIOn(w http.ResponseWriter, r *http.Request) {
+ log.Println("changing status: on")
+ setStatus(on)
+}
+
+func mockUIOff(w http.ResponseWriter, r *http.Request) {
+ log.Println("changing status: off")
+ setStatus(off)
+}
+
+func mockUIFailed(w http.ResponseWriter, r *http.Request) {
+ log.Println("changing status: failed")
+ setStatus(failed)
+}
+
+func mockUI() {
+ http.HandleFunc("/on", mockUIOn)
+ http.HandleFunc("/off", mockUIOff)
+ http.HandleFunc("/failed", mockUIFailed)
+ http.ListenAndServe(":8080", nil)
+}
+
+/*
+
+ exported C api
+
+*/
+
+//export SwitchOn
+func SwitchOn() {
+ setStatus(starting)
+ startVPN()
+}
+
+//export SwitchOff
+func SwitchOff() {
+ setStatus(stopping)
+ stopVPN()
+}
+
+//export Quit
+func Quit() {
+ if ctx.Status != off {
+ setStatus(stopping)
+ stopVPN()
+ }
+}
+
+//export Unblock
+func Unblock() {
+ fmt.Println("unblock... [not implemented]")
+}
+
+//export SubscribeToEvent
+func SubscribeToEvent(event string, f unsafe.Pointer) {
+ subscribe(event, f)
+}
+
+//export InitializeBitmaskContext
+func InitializeBitmaskContext() {
+ provider := "black.riseup.net"
+ appName := "RiseupVPN"
+ initOnce.Do(func() {
+ initializeContext(provider, appName)
+ })
+ go ctx.updateStatus()
+}
+
+//export RefreshContext
+func RefreshContext() *C.char {
+ c, _ := ctx.toJson()
+ return C.CString(string(c))
+}
+
+/* end of the exposed api */
+
+/* we could enable this one optionally for the qt tests */
+
+/* uncomment: export MockUIInteraction */
+func MockUIInteraction() {
+ log.Println("mocking ui interaction on port 8080. \nTry 'curl localhost:8080/{on|off|failed}' to toggle status.")
+ go mockUI()
+}
+
+func main() {}