1 files changed, 97 insertions, 0 deletions
diff --git a/actions/context.go b/actions/context.go
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+++ b/actions/context.go
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+/*
+ * context.go - top-level interface to fscrypt packages
+ *
+ * Copyright 2017 Google Inc.
+ * Author: Joe Richey (joerichey@google.com)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+// Package actions is the high-level interface to the fscrypt packages. The
+// functions here roughly correspond with commands for the tool in cmd/fscrypt.
+// All of the actions include a significant amount of logging, so that good
+// output can be provided for cmd/fscrypt's verbose mode.
+// The top-level actions currently include:
+//	- Creating a new config file
+//	- Creating a context on which to perform actions
+//	- Creating, unlocking, and modifying Protectors
+//	- Creating, unlocking, and modifying Policies
+package actions
+
+import (
+	"errors"
+	"fmt"
+	"log"
+
+	"fscrypt/filesystem"
+	"fscrypt/metadata"
+	"fscrypt/util"
+)
+
+// Errors relating to Config files or Config structures.
+var (
+	ErrNoConfigFile     = fmt.Errorf("config file %q does not exist", ConfigFileLocation)
+	ErrBadConfigFile    = fmt.Errorf("config file %q has invalid data", ConfigFileLocation)
+	ErrConfigFileExists = fmt.Errorf("config file %q already exists", ConfigFileLocation)
+	ErrBadConfig        = errors.New("invalid Config structure provided")
+)
+
+// Context contains the necessary global state to perform most of fscrypt's
+// actions. It contains a config struct, which is loaded from the global config
+// file, but can be edited manually. A context is specific to a filesystem, and
+// all actions to add, edit, remove, and apply Protectors and Policies are done
+// relative to that filesystem.
+type Context struct {
+	Config *metadata.Config
+	Mount  *filesystem.Mount
+}
+
+// NewContextFromPath makes a context for the filesystem containing the
+// specified path and whose Config is loaded from the global config file. On
+// success, the Context contains a valid Config and Mount.
+func NewContextFromPath(path string) (ctx *Context, err error) {
+	ctx = new(Context)
+
+	if ctx.Mount, err = filesystem.FindMount(path); err != nil {
+		err = util.UnderlyingError(err)
+		return
+	}
+
+	if ctx.Config, err = getConfig(); err != nil {
+		return
+	}
+
+	log.Printf("%s is on %s filesystem %q (%s)", path,
+		ctx.Mount.Filesystem, ctx.Mount.Path, ctx.Mount.Device)
+	return
+}
+
+// NewContextFromMountpoint makes a context for the filesystem at the specified
+// mountpoint and whose Config is loaded from the global config file. On
+// success, the Context contains a valid Config and Mount.
+func NewContextFromMountpoint(mountpoint string) (ctx *Context, err error) {
+	ctx = new(Context)
+
+	if ctx.Mount, err = filesystem.GetMount(mountpoint); err != nil {
+		err = util.UnderlyingError(err)
+		return
+	}
+
+	if ctx.Config, err = getConfig(); err != nil {
+		return
+	}
+
+	log.Printf("found %s filesystem %q (%s)", ctx.Mount.Filesystem,
+		ctx.Mount.Path, ctx.Mount.Device)
+	return
+}