From cbbe8e826c8c8d08e65c4e1073dcb6af602c20f3 Mon Sep 17 00:00:00 2001 From: Martchus Date: Sun, 8 Apr 2018 20:01:43 +0200 Subject: [PATCH] Add basic C bindings to start and stop Syncthing --- c-bindings/c_bindings.c | 11 ++ c-bindings/c_bindings.go | 231 +++++++++++++++++++++++++++++++++++++++ c-bindings/c_bindings.h | 11 ++ c-bindings/debug.go | 1 + 4 files changed, 254 insertions(+) create mode 100644 c-bindings/c_bindings.c create mode 100644 c-bindings/c_bindings.go create mode 100644 c-bindings/c_bindings.h create mode 120000 c-bindings/debug.go diff --git a/c-bindings/c_bindings.c b/c-bindings/c_bindings.c new file mode 100644 index 000000000..1dd98157f --- /dev/null +++ b/c-bindings/c_bindings.c @@ -0,0 +1,11 @@ +#include "c_bindings.h" + +libst_logging_callback_function_t libst_logging_callback_function = NULL; + +void libst_invoke_logging_callback(int log_level, const char *message, size_t message_size) +{ + if (!libst_logging_callback_function) { + return; + } + libst_logging_callback_function(log_level, message, message_size); +} diff --git a/c-bindings/c_bindings.go b/c-bindings/c_bindings.go new file mode 100644 index 000000000..91240a867 --- /dev/null +++ b/c-bindings/c_bindings.go @@ -0,0 +1,231 @@ +package main + +import ( + "context" + "os" + "unsafe" + "path/filepath" + _ "net/http/pprof" // Need to import this to support STPROFILER. + + "github.com/syncthing/syncthing/lib/build" + "github.com/syncthing/syncthing/lib/config" + "github.com/syncthing/syncthing/lib/events" + "github.com/syncthing/syncthing/lib/fs" + "github.com/syncthing/syncthing/lib/logger" + "github.com/syncthing/syncthing/lib/locations" + "github.com/syncthing/syncthing/lib/protocol" + "github.com/syncthing/syncthing/lib/svcutil" + "github.com/syncthing/syncthing/lib/syncthing" + "github.com/thejerf/suture/v4" +) + +// include header for required C helper functions (so the following comment is NO comment) + +// #include "c_bindings.h" +import "C" + +var theApp *syncthing.App +var myID protocol.DeviceID + +const ( + tlsDefaultCommonName = "syncthing" +) + +//export libst_own_device_id +func libst_own_device_id() string { + return myID.String() +} + +//export libst_init_logging +func libst_init_logging() { + l.AddHandler(logger.LevelVerbose, func(level logger.LogLevel, msg string) { + runes := []byte(msg) + length := len(runes) + if length <= 0 { + return + } + C.libst_invoke_logging_callback(C.int(level), (*C.char)(unsafe.Pointer(&runes[0])), C.size_t(len(runes))) + }) +} + +// C&P from main.go; used to ensure that the config directory exists +func ensureDir(dir string, mode fs.FileMode) error { + fs := fs.NewFilesystem(fs.FilesystemTypeBasic, dir) + err := fs.MkdirAll(".", mode) + if err != nil { + return err + } + + if fi, err := fs.Stat("."); err == nil { + // Apprently the stat may fail even though the mkdirall passed. If it + // does, we'll just assume things are in order and let other things + // fail (like loading or creating the config...). + currentMode := fi.Mode() & 0777 + if currentMode != mode { + err := fs.Chmod(".", mode) + // This can fail on crappy filesystems, nothing we can do about it. + if err != nil { + l.Warnln(err) + } + } + } + return nil +} + +//export libst_run_syncthing +func libst_run_syncthing(configDir string, dataDir string, guiAddress string, guiApiKey string, verbose bool, allowNewerConfig bool, noDefaultConfig bool, ensureConfigDirExists bool, ensureDataDirExists bool) int { + // return if already running (for simplicity we only allow one Syncthing instance at at time for now) + if theApp != nil { + return 0 + } + + // set specified GUI address and API key + if guiAddress != "" { + os.Setenv("STGUIADDRESS", guiAddress) + } + if guiApiKey != "" { + os.Setenv("STGUIAPIKEY", guiApiKey) + } + + // set specified config dir + if configDir != "" { + if !filepath.IsAbs(configDir) { + var err error + configDir, err = filepath.Abs(configDir) + if err != nil { + l.Warnln("Failed to make config path absolute:", err) + return 3 + } + } + if err := locations.SetBaseDir(locations.ConfigBaseDir, configDir); err != nil { + l.Warnln(err) + return 3 + } + } + + // set specified database dir + if dataDir != "" { + if !filepath.IsAbs(dataDir) { + var err error + dataDir, err = filepath.Abs(dataDir) + if err != nil { + l.Warnln("Failed to make database path absolute:", err) + return 3 + } + } + if err := locations.SetBaseDir(locations.DataBaseDir, dataDir); err != nil { + l.Warnln(err) + return 3 + } + } + + // ensure that the config directory exists + if ensureConfigDirExists { + if err := ensureDir(locations.GetBaseDir(locations.ConfigBaseDir), 0700); err != nil { + l.Warnln("Failed to create config directory:", err) + return 4 + } + } + + // ensure that the database directory exists + if dataDir != "" && ensureDataDirExists { + if err := ensureDir(locations.GetBaseDir(locations.DataBaseDir), 0700); err != nil { + l.Warnln("Failed to create database directory:", err) + return 4 + } + } + + // ensure that we have a certificate and key + cert, certErr := syncthing.LoadOrGenerateCertificate( + locations.Get(locations.CertFile), + locations.Get(locations.KeyFile), + ) + if certErr != nil { + l.Warnln("Failed to load/generate certificate:", certErr) + return 1 + } + + ctx, cancel := context.WithCancel(context.Background()) + defer cancel() + + // earlyService is a supervisor that runs the services needed for or + // before app startup; the event logger, and the config service. + spec := svcutil.SpecWithDebugLogger(l) + earlyService := suture.New("early", spec) + earlyService.ServeBackground(ctx) + + evLogger := events.NewLogger() + earlyService.Add(evLogger) + + // load config + configLocation := locations.Get(locations.ConfigFile) + l.Infoln("Loading config from:", configLocation) + cfgWrapper, cfgErr := syncthing.LoadConfigAtStartup(configLocation, cert, evLogger, allowNewerConfig, noDefaultConfig) + if cfgErr != nil { + l.Warnln("Failed to initialize config:", cfgErr) + return 2 + } + if cfgService, ok := cfgWrapper.(suture.Service); ok { + earlyService.Add(cfgService) + } + + // open database + dbFile := locations.Get(locations.Database) + l.Infoln("Opening database from:", dbFile) + ldb, dbErr := syncthing.OpenDBBackend(dbFile, config.TuningAuto) + if dbErr != nil { + l.Warnln("Error opening database:", dbErr) + return 4 + } + + appOpts := syncthing.Options{ + AssetDir: os.Getenv("STGUIASSETS"), + ProfilerAddr: os.Getenv("STPROFILER"), + NoUpgrade: true, + Verbose: verbose, + } + var err error + theApp, err = syncthing.New(cfgWrapper, ldb, evLogger, cert, appOpts) + if err != nil { + l.Warnln("Failed to start Syncthing:", err) + return svcutil.ExitError.AsInt() + } + + // start Syncthing and block until it has finished + returnCode := 0 + if err := theApp.Start(); err != nil { + returnCode = svcutil.ExitError.AsInt() + } + returnCode = theApp.Wait().AsInt(); + theApp = nil + return returnCode +} + +//export libst_stop_syncthing +func libst_stop_syncthing() int { + if theApp != nil { + return int(theApp.Stop(svcutil.ExitSuccess)) + } else { + return 0; + } +} + +//export libst_reset_database +func libst_reset_database() { + os.RemoveAll(locations.Get(locations.Database)) +} + +//export libst_syncthing_version +func libst_syncthing_version() *C.char { + return C.CString(build.Version) +} + +//export libst_long_syncthing_version +func libst_long_syncthing_version() *C.char { + return C.CString(build.LongVersion) +} + +func main() { + // prevent "runtime.main_main·f: function main is undeclared in the main package" +} + diff --git a/c-bindings/c_bindings.h b/c-bindings/c_bindings.h new file mode 100644 index 000000000..e4e32ecb3 --- /dev/null +++ b/c-bindings/c_bindings.h @@ -0,0 +1,11 @@ +#ifndef LIBSYNCTHING_INTERNAL_H +#define LIBSYNCTHING_INTERNAL_H + +#include + +// allow registration of callback function +typedef void (*libst_logging_callback_function_t) (int logLevel, const char *msg, size_t msgSize); +extern libst_logging_callback_function_t libst_logging_callback_function; +extern void libst_invoke_logging_callback(int log_level, const char *message, size_t message_size); + +#endif // LIBSYNCTHING_INTERNAL_H diff --git a/c-bindings/debug.go b/c-bindings/debug.go new file mode 120000 index 000000000..117c10801 --- /dev/null +++ b/c-bindings/debug.go @@ -0,0 +1 @@ +../cmd/syncthing/debug.go \ No newline at end of file