Restore whole folder to sdtout as tar

With this change it is possible to dump a folder to stdout as a tar. The

It can be used just like the normal dump command:

`./restic dump fa97e6e1 "/data/test/" > test.tar`

Where `/data/test/` is a a folder instead of a file.

build.go

@@ -60,12 +60,12 @@ import (
 
 // config contains the configuration for the program to build.
 var config = Config{
-	Name:             "restic",                                // name of the program executable and directory
-	Namespace:        "github.com/restic/restic",              // subdir of GOPATH, e.g. "github.com/foo/bar"
-	Main:             "./cmd/restic",                          // package name for the main package
-	DefaultBuildTags: []string{"selfupdate"},                  // specify build tags which are always used
-	Tests:            []string{"./..."},                       // tests to run
-	MinVersion:       GoVersion{Major: 1, Minor: 9, Patch: 0}, // minimum Go version supported
+	Name:             "restic",                                 // name of the program executable and directory
+	Namespace:        "github.com/restic/restic",               // subdir of GOPATH, e.g. "github.com/foo/bar"
+	Main:             "./cmd/restic",                           // package name for the main package
+	DefaultBuildTags: []string{"selfupdate"},                   // specify build tags which are always used
+	Tests:            []string{"./..."},                        // tests to run
+	MinVersion:       GoVersion{Major: 1, Minor: 10, Patch: 0}, // minimum Go version supported
 }
 
 // Config configures the build.

changelog/unreleased/pull-2124

@@ -0,0 +1,8 @@
+Enhancement: Ability to dump folders to tar via stdout
+
+We've added the ability to dump whole folders to stdout via the `dump` command.
+Restic now requires at least Go 1.10 due to a limitation of the standard
+library for Go <= 1.9.
+
+https://github.com/restic/restic/pull/2124
+https://github.com/restic/restic/issues/2123

cmd/restic/acl.go

@@ -0,0 +1,131 @@
+package main
+
+// Adapted from https://github.com/maxymania/go-system/blob/master/posix_acl/posix_acl.go
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+)
+
+const (
+	aclUserOwner  = 0x0001
+	aclUser       = 0x0002
+	aclGroupOwner = 0x0004
+	aclGroup      = 0x0008
+	aclMask       = 0x0010
+	aclOthers     = 0x0020
+)
+
+type aclSID uint64
+
+type aclElem struct {
+	Tag  uint16
+	Perm uint16
+	ID   uint32
+}
+
+type acl struct {
+	Version uint32
+	List    []aclElement
+}
+
+type aclElement struct {
+	aclSID
+	Perm uint16
+}
+
+func (a *aclSID) setUID(uid uint32) {
+	*a = aclSID(uid) | (aclUser << 32)
+}
+func (a *aclSID) setGID(gid uint32) {
+	*a = aclSID(gid) | (aclGroup << 32)
+}
+
+func (a *aclSID) setType(tp int) {
+	*a = aclSID(tp) << 32
+}
+
+func (a aclSID) getType() int {
+	return int(a >> 32)
+}
+func (a aclSID) getID() uint32 {
+	return uint32(a & 0xffffffff)
+}
+func (a aclSID) String() string {
+	switch a >> 32 {
+	case aclUserOwner:
+		return "user::"
+	case aclUser:
+		return fmt.Sprintf("user:%v:", a.getID())
+	case aclGroupOwner:
+		return "group::"
+	case aclGroup:
+		return fmt.Sprintf("group:%v:", a.getID())
+	case aclMask:
+		return "mask::"
+	case aclOthers:
+		return "other::"
+	}
+	return "?:"
+}
+
+func (a aclElement) String() string {
+	str := ""
+	if (a.Perm & 4) != 0 {
+		str += "r"
+	} else {
+		str += "-"
+	}
+	if (a.Perm & 2) != 0 {
+		str += "w"
+	} else {
+		str += "-"
+	}
+	if (a.Perm & 1) != 0 {
+		str += "x"
+	} else {
+		str += "-"
+	}
+	return fmt.Sprintf("%v%v", a.aclSID, str)
+}
+
+func (a *acl) decode(xattr []byte) {
+	var elem aclElement
+	ae := new(aclElem)
+	nr := bytes.NewReader(xattr)
+	e := binary.Read(nr, binary.LittleEndian, &a.Version)
+	if e != nil {
+		a.Version = 0
+		return
+	}
+	if len(a.List) > 0 {
+		a.List = a.List[:0]
+	}
+	for binary.Read(nr, binary.LittleEndian, ae) == nil {
+		elem.aclSID = (aclSID(ae.Tag) << 32) | aclSID(ae.ID)
+		elem.Perm = ae.Perm
+		a.List = append(a.List, elem)
+	}
+}
+
+func (a *acl) encode() []byte {
+	buf := new(bytes.Buffer)
+	ae := new(aclElem)
+	binary.Write(buf, binary.LittleEndian, &a.Version)
+	for _, elem := range a.List {
+		ae.Tag = uint16(elem.getType())
+		ae.Perm = elem.Perm
+		ae.ID = elem.getID()
+		binary.Write(buf, binary.LittleEndian, ae)
+	}
+	return buf.Bytes()
+}
+
+func (a *acl) String() string {
+	var finalacl string
+	for _, acl := range a.List {
+		finalacl += acl.String() + "\n"
+	}
+	return finalacl
+}

cmd/restic/acl_test.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func Test_acl_decode(t *testing.T) {
+	type args struct {
+		xattr []byte
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			name: "decode string",
+			args: args{
+				xattr: []byte{2, 0, 0, 0, 1, 0, 6, 0, 255, 255, 255, 255, 2, 0, 7, 0, 0, 0, 0, 0, 2, 0, 7, 0, 254, 255, 0, 0, 4, 0, 7, 0, 255, 255, 255, 255, 16, 0, 7, 0, 255, 255, 255, 255, 32, 0, 4, 0, 255, 255, 255, 255},
+			},
+			want: "user::rw-\nuser:0:rwx\nuser:65534:rwx\ngroup::rwx\nmask::rwx\nother::r--\n",
+		},
+		{
+			name: "decode fail",
+			args: args{
+				xattr: []byte("abctest"),
+			},
+			want: "",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			a := &acl{}
+			a.decode(tt.args.xattr)
+			if tt.want != a.String() {
+				t.Errorf("acl.decode() = %v, want: %v", a.String(), tt.want)
+			}
+		})
+	}
+}
+
+func Test_acl_encode(t *testing.T) {
+	tests := []struct {
+		name string
+		want []byte
+		args []aclElement
+	}{
+		{
+			name: "encode values",
+			want: []byte{2, 0, 0, 0, 1, 0, 6, 0, 255, 255, 255, 255, 2, 0, 7, 0, 0, 0, 0, 0, 2, 0, 7, 0, 254, 255, 0, 0, 4, 0, 7, 0, 255, 255, 255, 255, 16, 0, 7, 0, 255, 255, 255, 255, 32, 0, 4, 0, 255, 255, 255, 255},
+			args: []aclElement{
+				{
+					aclSID: 8589934591,
+					Perm:   6,
+				},
+				{
+					aclSID: 8589934592,
+					Perm:   7,
+				},
+				{
+					aclSID: 8590000126,
+					Perm:   7,
+				},
+				{
+					aclSID: 21474836479,
+					Perm:   7,
+				},
+				{
+					aclSID: 73014444031,
+					Perm:   7,
+				},
+				{
+					aclSID: 141733920767,
+					Perm:   4,
+				},
+			},
+		},
+		{
+			name: "encode fail",
+			want: []byte{2, 0, 0, 0},
+			args: []aclElement{},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			a := &acl{
+				Version: 2,
+				List:    tt.args,
+			}
+			if got := a.encode(); !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("acl.encode() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}