conf: separate out migration and print errors

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

3 files changed, 90 insertions, 77 deletions

diff --git a/conf/migration.go b/conf/migration.go
new file mode 100644
index 00000000..4b68763f
--- /dev/null
+++ b/conf/migration.go
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019-2020 WireGuard LLC. All Rights Reserved.
+ */
+
+package conf
+
+import (
+	"errors"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"golang.org/x/sys/windows"
+)
+
+var migrating sync.Mutex
+var lastMigrationTimer *time.Timer
+
+func MigrateUnencryptedConfigs() { migrateUnencryptedConfigs(3) }
+
+func migrateUnencryptedConfigs(sharingBase int) {
+	migrating.Lock()
+	defer migrating.Unlock()
+	configFileDir, err := tunnelConfigurationsDirectory()
+	if err != nil {
+		return
+	}
+	files, err := ioutil.ReadDir(configFileDir)
+	if err != nil {
+		return
+	}
+	ignoreSharingViolations := false
+	for _, file := range files {
+		path := filepath.Join(configFileDir, file.Name())
+		name := filepath.Base(file.Name())
+		if len(name) <= len(configFileUnencryptedSuffix) || !strings.HasSuffix(name, configFileUnencryptedSuffix) {
+			continue
+		}
+		if !file.Mode().IsRegular() || file.Mode().Perm()&0444 == 0 {
+			continue
+		}
+
+		var bytes []byte
+		var config *Config
+		// We don't use ioutil's ReadFile, because we actually want RDWR, so that we can take advantage
+		// of Windows file locking for ensuring the file is finished being written.
+		f, err := os.OpenFile(path, os.O_RDWR, 0)
+		if err != nil {
+			if errors.Is(err, windows.ERROR_SHARING_VIOLATION) {
+				if ignoreSharingViolations {
+					continue
+				} else if sharingBase > 0 {
+					if lastMigrationTimer != nil {
+						lastMigrationTimer.Stop()
+					}
+					lastMigrationTimer = time.AfterFunc(time.Second/time.Duration(sharingBase*sharingBase), func() { migrateUnencryptedConfigs(sharingBase - 1) })
+					ignoreSharingViolations = true
+					continue
+				}
+			}
+			goto error
+		}
+		bytes, err = ioutil.ReadAll(f)
+		f.Close()
+		if err != nil {
+			goto error
+		}
+		config, err = FromWgQuickWithUnknownEncoding(string(bytes), strings.TrimSuffix(name, configFileUnencryptedSuffix))
+		if err != nil {
+			goto error
+		}
+		err = config.Save(false)
+		if err != nil {
+			goto error
+		}
+		err = os.Remove(path)
+		if err != nil {
+			log.Printf("Unable to remove old path %#q: %v", path, err)
+		}
+		continue
+	error:
+		log.Printf("Unable to ingest and encrypt %#q: %v", path, err)
+	}
+}
diff --git a/conf/store.go b/conf/store.go
index 5cc2ce46..18f99f66 100644
--- a/conf/store.go
+++ b/conf/store.go
@@ -11,10 +11,6 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
-	"sync"
-	"time"
-
-	"golang.org/x/sys/windows"
 
 	"golang.zx2c4.com/wireguard/windows/conf/dpapi"
 )
@@ -51,78 +47,6 @@ func ListConfigNames() ([]string, error) {
 	return configs[:i], nil
 }
 
-var migrating sync.Mutex
-var lastMigrationTimer *time.Timer
-
-func MigrateUnencryptedConfigs(sharingBase int) (int, []error) {
-	migrating.Lock()
-	defer migrating.Unlock()
-	configFileDir, err := tunnelConfigurationsDirectory()
-	if err != nil {
-		return 0, []error{err}
-	}
-	files, err := ioutil.ReadDir(configFileDir)
-	if err != nil {
-		return 0, []error{err}
-	}
-	errs := make([]error, len(files))
-	i := 0
-	e := 0
-	for _, file := range files {
-		path := filepath.Join(configFileDir, file.Name())
-		name := filepath.Base(file.Name())
-		if len(name) <= len(configFileUnencryptedSuffix) || !strings.HasSuffix(name, configFileUnencryptedSuffix) {
-			continue
-		}
-		if !file.Mode().IsRegular() || file.Mode().Perm()&0444 == 0 {
-			continue
-		}
-
-		// We don't use ioutil's ReadFile, because we actually want RDWR, so that we can take advantage
-		// of Windows file locking for ensuring the file is finished being written.
-		f, err := os.OpenFile(path, os.O_RDWR, 0)
-		if err != nil {
-			if sharingBase > 0 && errors.Is(err, windows.ERROR_SHARING_VIOLATION) {
-				if lastMigrationTimer != nil {
-					lastMigrationTimer.Stop()
-				}
-				lastMigrationTimer = time.AfterFunc(time.Second/time.Duration(sharingBase*sharingBase), func() { MigrateUnencryptedConfigs(sharingBase - 1) })
-				sharingBase = 0
-			}
-			errs[e] = err
-			e++
-			continue
-		}
-		bytes, err := ioutil.ReadAll(f)
-		f.Close()
-		if err != nil {
-			errs[e] = err
-			e++
-			continue
-		}
-		config, err := FromWgQuickWithUnknownEncoding(string(bytes), strings.TrimSuffix(name, configFileUnencryptedSuffix))
-		if err != nil {
-			errs[e] = err
-			e++
-			continue
-		}
-		err = config.Save(false)
-		if err != nil {
-			errs[e] = err
-			e++
-			continue
-		}
-		err = os.Remove(path)
-		if err != nil {
-			errs[e] = err
-			e++
-			continue
-		}
-		i++
-	}
-	return i, errs[:e]
-}
-
 func LoadFromName(name string) (*Config, error) {
 	configFileDir, err := tunnelConfigurationsDirectory()
 	if err != nil {
diff --git a/manager/service.go b/manager/service.go
index 9044d9fb..2afd796f 100644
--- a/manager/service.go
+++ b/manager/service.go
@@ -85,7 +85,7 @@ func (service *managerService) Execute(args []string, r <-chan svc.ChangeRequest
 		return
 	}
 
-	conf.RegisterStoreChangeCallback(func() { conf.MigrateUnencryptedConfigs(3) })
+	conf.RegisterStoreChangeCallback(conf.MigrateUnencryptedConfigs)
 	conf.RegisterStoreChangeCallback(IPCServerNotifyTunnelsChange)
 
 	procs := make(map[uint32]*os.Process)