diff options
Diffstat (limited to 'vendor/github.com/digitalocean/go-libvirt/internal/go-xdr')
5 files changed, 1926 insertions, 0 deletions
diff --git a/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/LICENSE b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/LICENSE new file mode 100644 index 000000000..0cc3543ce --- /dev/null +++ b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/LICENSE @@ -0,0 +1,13 @@ +Copyright (c) 2012-2014 Dave Collins <dave@davec.name> + +Permission to use, copy, modify, and distribute this software for any +purpose with or without fee is hereby granted, provided that the above +copyright notice and this permission notice appear in all copies. + +THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
\ No newline at end of file diff --git a/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/decode.go b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/decode.go new file mode 100644 index 000000000..7f33f7d32 --- /dev/null +++ b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/decode.go @@ -0,0 +1,896 @@ +/* + * Copyright (c) 2012-2014 Dave Collins <dave@davec.name> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +package xdr + +import ( + "fmt" + "io" + "math" + "reflect" + "time" +) + +var ( + errMaxSlice = "data exceeds max slice limit" + errIODecode = "%s while decoding %d bytes" +) + +/* +Unmarshal parses XDR-encoded data into the value pointed to by v reading from +reader r and returning the total number of bytes read. An addressable pointer +must be provided since Unmarshal needs to both store the result of the decode as +well as obtain target type information. Unmarhsal traverses v recursively and +automatically indirects pointers through arbitrary depth, allocating them as +necessary, to decode the data into the underlying value pointed to. + +Unmarshal uses reflection to determine the type of the concrete value contained +by v and performs a mapping of underlying XDR types to Go types as follows: + + Go Type <- XDR Type + -------------------- + int8, int16, int32, int <- XDR Integer + uint8, uint16, uint32, uint <- XDR Unsigned Integer + int64 <- XDR Hyper Integer + uint64 <- XDR Unsigned Hyper Integer + bool <- XDR Boolean + float32 <- XDR Floating-Point + float64 <- XDR Double-Precision Floating-Point + string <- XDR String + byte <- XDR Integer + []byte <- XDR Variable-Length Opaque Data + [#]byte <- XDR Fixed-Length Opaque Data + []<type> <- XDR Variable-Length Array + [#]<type> <- XDR Fixed-Length Array + struct <- XDR Structure + map <- XDR Variable-Length Array of two-element XDR Structures + time.Time <- XDR String encoded with RFC3339 nanosecond precision + +Notes and Limitations: + + * Automatic unmarshalling of variable and fixed-length arrays of uint8s + requires a special struct tag `xdropaque:"false"` since byte slices + and byte arrays are assumed to be opaque data and byte is a Go alias + for uint8 thus indistinguishable under reflection + * Cyclic data structures are not supported and will result in infinite + loops + +If any issues are encountered during the unmarshalling process, an +UnmarshalError is returned with a human readable description as well as +an ErrorCode value for further inspection from sophisticated callers. Some +potential issues are unsupported Go types, attempting to decode a value which is +too large to fit into a specified Go type, and exceeding max slice limitations. +*/ +func Unmarshal(r io.Reader, v interface{}) (int, error) { + d := Decoder{r: r} + return d.Decode(v) +} + +// UnmarshalLimited is identical to Unmarshal but it sets maxReadSize in order +// to cap reads. +func UnmarshalLimited(r io.Reader, v interface{}, maxSize uint) (int, error) { + d := Decoder{r: r, maxReadSize: maxSize} + return d.Decode(v) +} + +// TypeDecoder lets a caller provide a custom decode routine for a custom type. +type TypeDecoder interface { + Decode(*Decoder, reflect.Value) (int, error) +} + +// A Decoder wraps an io.Reader that is expected to provide an XDR-encoded byte +// stream and provides several exposed methods to manually decode various XDR +// primitives without relying on reflection. The NewDecoder function can be +// used to get a new Decoder directly. +// +// Typically, Unmarshal should be used instead of manual decoding. A Decoder +// is exposed so it is possible to perform manual decoding should it be +// necessary in complex scenarios where automatic reflection-based decoding +// won't work. +type Decoder struct { + r io.Reader + + // maxReadSize is the default maximum bytes an element can contain. 0 + // is unlimited and provides backwards compatability. Setting it to a + // non-zero value caps reads. + maxReadSize uint + + // customTypes is a map allowing the caller to provide decoder routines for + // custom types known only to itself. + customTypes map[string]TypeDecoder +} + +// DecodeInt treats the next 4 bytes as an XDR encoded integer and returns the +// result as an int32 along with the number of bytes actually read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining. +// +// Reference: +// RFC Section 4.1 - Integer +// 32-bit big-endian signed integer in range [-2147483648, 2147483647] +func (d *Decoder) DecodeInt() (int32, int, error) { + var buf [4]byte + n, err := io.ReadFull(d.r, buf[:]) + if err != nil { + msg := fmt.Sprintf(errIODecode, err.Error(), 4) + err := unmarshalError("DecodeInt", ErrIO, msg, buf[:n], err) + return 0, n, err + } + + rv := int32(buf[3]) | int32(buf[2])<<8 | + int32(buf[1])<<16 | int32(buf[0])<<24 + return rv, n, nil +} + +// DecodeUint treats the next 4 bytes as an XDR encoded unsigned integer and +// returns the result as a uint32 along with the number of bytes actually read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining. +// +// Reference: +// RFC Section 4.2 - Unsigned Integer +// 32-bit big-endian unsigned integer in range [0, 4294967295] +func (d *Decoder) DecodeUint() (uint32, int, error) { + var buf [4]byte + n, err := io.ReadFull(d.r, buf[:]) + if err != nil { + msg := fmt.Sprintf(errIODecode, err.Error(), 4) + err := unmarshalError("DecodeUint", ErrIO, msg, buf[:n], err) + return 0, n, err + } + + rv := uint32(buf[3]) | uint32(buf[2])<<8 | + uint32(buf[1])<<16 | uint32(buf[0])<<24 + return rv, n, nil +} + +// DecodeEnum treats the next 4 bytes as an XDR encoded enumeration value and +// returns the result as an int32 after verifying that the value is in the +// provided map of valid values. It also returns the number of bytes actually +// read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining or +// the parsed enumeration value is not one of the provided valid values. +// +// Reference: +// RFC Section 4.3 - Enumeration +// Represented as an XDR encoded signed integer +func (d *Decoder) DecodeEnum(validEnums map[int32]bool) (int32, int, error) { + val, n, err := d.DecodeInt() + if err != nil { + return 0, n, err + } + + if !validEnums[val] { + err := unmarshalError("DecodeEnum", ErrBadEnumValue, + "invalid enum", val, nil) + return 0, n, err + } + return val, n, nil +} + +// DecodeBool treats the next 4 bytes as an XDR encoded boolean value and +// returns the result as a bool along with the number of bytes actually read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining or +// the parsed value is not a 0 or 1. +// +// Reference: +// RFC Section 4.4 - Boolean +// Represented as an XDR encoded enumeration where 0 is false and 1 is true +func (d *Decoder) DecodeBool() (bool, int, error) { + val, n, err := d.DecodeInt() + if err != nil { + return false, n, err + } + switch val { + case 0: + return false, n, nil + case 1: + return true, n, nil + } + + err = unmarshalError("DecodeBool", ErrBadEnumValue, "bool not 0 or 1", + val, nil) + return false, n, err +} + +// DecodeHyper treats the next 8 bytes as an XDR encoded hyper value and +// returns the result as an int64 along with the number of bytes actually read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining. +// +// Reference: +// RFC Section 4.5 - Hyper Integer +// 64-bit big-endian signed integer in range [-9223372036854775808, 9223372036854775807] +func (d *Decoder) DecodeHyper() (int64, int, error) { + var buf [8]byte + n, err := io.ReadFull(d.r, buf[:]) + if err != nil { + msg := fmt.Sprintf(errIODecode, err.Error(), 8) + err := unmarshalError("DecodeHyper", ErrIO, msg, buf[:n], err) + return 0, n, err + } + + rv := int64(buf[7]) | int64(buf[6])<<8 | + int64(buf[5])<<16 | int64(buf[4])<<24 | + int64(buf[3])<<32 | int64(buf[2])<<40 | + int64(buf[1])<<48 | int64(buf[0])<<56 + return rv, n, err +} + +// DecodeUhyper treats the next 8 bytes as an XDR encoded unsigned hyper value +// and returns the result as a uint64 along with the number of bytes actually +// read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining. +// +// Reference: +// RFC Section 4.5 - Unsigned Hyper Integer +// 64-bit big-endian unsigned integer in range [0, 18446744073709551615] +func (d *Decoder) DecodeUhyper() (uint64, int, error) { + var buf [8]byte + n, err := io.ReadFull(d.r, buf[:]) + if err != nil { + msg := fmt.Sprintf(errIODecode, err.Error(), 8) + err := unmarshalError("DecodeUhyper", ErrIO, msg, buf[:n], err) + return 0, n, err + } + + rv := uint64(buf[7]) | uint64(buf[6])<<8 | + uint64(buf[5])<<16 | uint64(buf[4])<<24 | + uint64(buf[3])<<32 | uint64(buf[2])<<40 | + uint64(buf[1])<<48 | uint64(buf[0])<<56 + return rv, n, nil +} + +// DecodeFloat treats the next 4 bytes as an XDR encoded floating point and +// returns the result as a float32 along with the number of bytes actually read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining. +// +// Reference: +// RFC Section 4.6 - Floating Point +// 32-bit single-precision IEEE 754 floating point +func (d *Decoder) DecodeFloat() (float32, int, error) { + var buf [4]byte + n, err := io.ReadFull(d.r, buf[:]) + if err != nil { + msg := fmt.Sprintf(errIODecode, err.Error(), 4) + err := unmarshalError("DecodeFloat", ErrIO, msg, buf[:n], err) + return 0, n, err + } + + val := uint32(buf[3]) | uint32(buf[2])<<8 | + uint32(buf[1])<<16 | uint32(buf[0])<<24 + return math.Float32frombits(val), n, nil +} + +// DecodeDouble treats the next 8 bytes as an XDR encoded double-precision +// floating point and returns the result as a float64 along with the number of +// bytes actually read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining. +// +// Reference: +// RFC Section 4.7 - Double-Precision Floating Point +// 64-bit double-precision IEEE 754 floating point +func (d *Decoder) DecodeDouble() (float64, int, error) { + var buf [8]byte + n, err := io.ReadFull(d.r, buf[:]) + if err != nil { + msg := fmt.Sprintf(errIODecode, err.Error(), 8) + err := unmarshalError("DecodeDouble", ErrIO, msg, buf[:n], err) + return 0, n, err + } + + val := uint64(buf[7]) | uint64(buf[6])<<8 | + uint64(buf[5])<<16 | uint64(buf[4])<<24 | + uint64(buf[3])<<32 | uint64(buf[2])<<40 | + uint64(buf[1])<<48 | uint64(buf[0])<<56 + return math.Float64frombits(val), n, nil +} + +// RFC Section 4.8 - Quadruple-Precision Floating Point +// 128-bit quadruple-precision floating point +// Not Implemented + +// DecodeFixedOpaque treats the next 'size' bytes as XDR encoded opaque data and +// returns the result as a byte slice along with the number of bytes actually +// read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining to +// satisfy the passed size, including the necessary padding to make it a +// multiple of 4. +// +// Reference: +// RFC Section 4.9 - Fixed-Length Opaque Data +// Fixed-length uninterpreted data zero-padded to a multiple of four +func (d *Decoder) DecodeFixedOpaque(size int32) ([]byte, int, error) { + // Nothing to do if size is 0. + if size == 0 { + return nil, 0, nil + } + + pad := (4 - (size % 4)) % 4 + paddedSize := size + pad + if uint(paddedSize) > uint(math.MaxInt32) { + err := unmarshalError("DecodeFixedOpaque", ErrOverflow, + errMaxSlice, paddedSize, nil) + return nil, 0, err + } + + buf := make([]byte, paddedSize) + n, err := io.ReadFull(d.r, buf) + if err != nil { + msg := fmt.Sprintf(errIODecode, err.Error(), paddedSize) + err := unmarshalError("DecodeFixedOpaque", ErrIO, msg, buf[:n], + err) + return nil, n, err + } + return buf[0:size], n, nil +} + +// DecodeOpaque treats the next bytes as variable length XDR encoded opaque +// data and returns the result as a byte slice along with the number of bytes +// actually read. +// +// An UnmarshalError is returned if there are insufficient bytes remaining or +// the opaque data is larger than the max length of a Go slice. +// +// Reference: +// RFC Section 4.10 - Variable-Length Opaque Data +// Unsigned integer length followed by fixed opaque data of that length +func (d *Decoder) DecodeOpaque() ([]byte, int, error) { + dataLen, n, err := d.DecodeUint() + if err != nil { + return nil, n, err + } + if uint(dataLen) > uint(math.MaxInt32) || + (d.maxReadSize != 0 && uint(dataLen) > d.maxReadSize) { + err := unmarshalError("DecodeOpaque", ErrOverflow, errMaxSlice, + dataLen, nil) + return nil, n, err + } + + rv, n2, err := d.DecodeFixedOpaque(int32(dataLen)) + n += n2 + if err != nil { + return nil, n, err + } + return rv, n, nil +} + +// DecodeString treats the next bytes as a variable length XDR encoded string +// and returns the result as a string along with the number of bytes actually +// read. Character encoding is assumed to be UTF-8 and therefore ASCII +// compatible. If the underlying character encoding is not compatibile with +// this assumption, the data can instead be read as variable-length opaque data +// (DecodeOpaque) and manually converted as needed. +// +// An UnmarshalError is returned if there are insufficient bytes remaining or +// the string data is larger than the max length of a Go slice. +// +// Reference: +// RFC Section 4.11 - String +// Unsigned integer length followed by bytes zero-padded to a multiple of +// four +func (d *Decoder) DecodeString() (string, int, error) { + dataLen, n, err := d.DecodeUint() + if err != nil { + return "", n, err + } + if uint(dataLen) > uint(math.MaxInt32) || + (d.maxReadSize != 0 && uint(dataLen) > d.maxReadSize) { + err = unmarshalError("DecodeString", ErrOverflow, errMaxSlice, + dataLen, nil) + return "", n, err + } + + opaque, n2, err := d.DecodeFixedOpaque(int32(dataLen)) + n += n2 + if err != nil { + return "", n, err + } + return string(opaque), n, nil +} + +// decodeFixedArray treats the next bytes as a series of XDR encoded elements +// of the same type as the array represented by the reflection value and decodes +// each element into the passed array. The ignoreOpaque flag controls whether +// or not uint8 (byte) elements should be decoded individually or as a fixed +// sequence of opaque data. It returns the the number of bytes actually read. +// +// An UnmarshalError is returned if any issues are encountered while decoding +// the array elements. +// +// Reference: +// RFC Section 4.12 - Fixed-Length Array +// Individually XDR encoded array elements +func (d *Decoder) decodeFixedArray(v reflect.Value, ignoreOpaque bool) (int, error) { + // Treat [#]byte (byte is alias for uint8) as opaque data unless + // ignored. + if !ignoreOpaque && v.Type().Elem().Kind() == reflect.Uint8 { + data, n, err := d.DecodeFixedOpaque(int32(v.Len())) + if err != nil { + return n, err + } + reflect.Copy(v, reflect.ValueOf(data)) + return n, nil + } + + // Decode each array element. + var n int + for i := 0; i < v.Len(); i++ { + n2, err := d.decode(v.Index(i)) + n += n2 + if err != nil { + return n, err + } + } + return n, nil +} + +// decodeArray treats the next bytes as a variable length series of XDR encoded +// elements of the same type as the array represented by the reflection value. +// The number of elements is obtained by first decoding the unsigned integer +// element count. Then each element is decoded into the passed array. The +// ignoreOpaque flag controls whether or not uint8 (byte) elements should be +// decoded individually or as a variable sequence of opaque data. It returns +// the number of bytes actually read. +// +// An UnmarshalError is returned if any issues are encountered while decoding +// the array elements. +// +// Reference: +// RFC Section 4.13 - Variable-Length Array +// Unsigned integer length followed by individually XDR encoded array +// elements +func (d *Decoder) decodeArray(v reflect.Value, ignoreOpaque bool) (int, error) { + dataLen, n, err := d.DecodeUint() + if err != nil { + return n, err + } + if uint(dataLen) > uint(math.MaxInt32) || + (d.maxReadSize != 0 && uint(dataLen) > d.maxReadSize) { + err := unmarshalError("decodeArray", ErrOverflow, errMaxSlice, + dataLen, nil) + return n, err + } + + // Allocate storage for the slice elements (the underlying array) if + // existing slice does not have enough capacity. + sliceLen := int(dataLen) + if v.Cap() < sliceLen { + v.Set(reflect.MakeSlice(v.Type(), sliceLen, sliceLen)) + } + if v.Len() < sliceLen { + v.SetLen(sliceLen) + } + + // Treat []byte (byte is alias for uint8) as opaque data unless ignored. + if !ignoreOpaque && v.Type().Elem().Kind() == reflect.Uint8 { + data, n2, err := d.DecodeFixedOpaque(int32(sliceLen)) + n += n2 + if err != nil { + return n, err + } + v.SetBytes(data) + return n, nil + } + + // Decode each slice element. + for i := 0; i < sliceLen; i++ { + n2, err := d.decode(v.Index(i)) + n += n2 + if err != nil { + return n, err + } + } + return n, nil +} + +// decodeStruct treats the next bytes as a series of XDR encoded elements +// of the same type as the exported fields of the struct represented by the +// passed reflection value. Pointers are automatically indirected and +// allocated as necessary. It returns the the number of bytes actually read. +// +// An UnmarshalError is returned if any issues are encountered while decoding +// the elements. +// +// Reference: +// RFC Section 4.14 - Structure +// XDR encoded elements in the order of their declaration in the struct +func (d *Decoder) decodeStruct(v reflect.Value) (int, error) { + var n int + vt := v.Type() + for i := 0; i < v.NumField(); i++ { + // Skip unexported fields. + vtf := vt.Field(i) + if vtf.PkgPath != "" { + continue + } + + // Indirect through pointers allocating them as needed and + // ensure the field is settable. + vf := v.Field(i) + vf, err := d.indirect(vf) + if err != nil { + return n, err + } + if !vf.CanSet() { + msg := fmt.Sprintf("can't decode to unsettable '%v'", + vf.Type().String()) + err := unmarshalError("decodeStruct", ErrNotSettable, + msg, nil, nil) + return n, err + } + + // Handle non-opaque data to []uint8 and [#]uint8 based on + // struct tag. + tag := vtf.Tag.Get("xdropaque") + if tag == "false" { + switch vf.Kind() { + case reflect.Slice: + n2, err := d.decodeArray(vf, true) + n += n2 + if err != nil { + return n, err + } + continue + + case reflect.Array: + n2, err := d.decodeFixedArray(vf, true) + n += n2 + if err != nil { + return n, err + } + continue + } + } + + // Decode each struct field. + n2, err := d.decode(vf) + n += n2 + if err != nil { + return n, err + } + } + + return n, nil +} + +// RFC Section 4.15 - Discriminated Union +// RFC Section 4.16 - Void +// RFC Section 4.17 - Constant +// RFC Section 4.18 - Typedef +// RFC Section 4.19 - Optional data +// RFC Sections 4.15 though 4.19 only apply to the data specification language +// which is not implemented by this package. In the case of discriminated +// unions, struct tags are used to perform a similar function. + +// decodeMap treats the next bytes as an XDR encoded variable array of 2-element +// structures whose fields are of the same type as the map keys and elements +// represented by the passed reflection value. Pointers are automatically +// indirected and allocated as necessary. It returns the the number of bytes +// actually read. +// +// An UnmarshalError is returned if any issues are encountered while decoding +// the elements. +func (d *Decoder) decodeMap(v reflect.Value) (int, error) { + dataLen, n, err := d.DecodeUint() + if err != nil { + return n, err + } + + // Allocate storage for the underlying map if needed. + vt := v.Type() + if v.IsNil() { + v.Set(reflect.MakeMap(vt)) + } + + // Decode each key and value according to their type. + keyType := vt.Key() + elemType := vt.Elem() + for i := uint32(0); i < dataLen; i++ { + key := reflect.New(keyType).Elem() + n2, err := d.decode(key) + n += n2 + if err != nil { + return n, err + } + + val := reflect.New(elemType).Elem() + n2, err = d.decode(val) + n += n2 + if err != nil { + return n, err + } + v.SetMapIndex(key, val) + } + return n, nil +} + +// decodeInterface examines the interface represented by the passed reflection +// value to detect whether it is an interface that can be decoded into and +// if it is, extracts the underlying value to pass back into the decode function +// for decoding according to its type. It returns the the number of bytes +// actually read. +// +// An UnmarshalError is returned if any issues are encountered while decoding +// the interface. +func (d *Decoder) decodeInterface(v reflect.Value) (int, error) { + if v.IsNil() || !v.CanInterface() { + msg := fmt.Sprintf("can't decode to nil interface") + err := unmarshalError("decodeInterface", ErrNilInterface, msg, + nil, nil) + return 0, err + } + + // Extract underlying value from the interface and indirect through + // pointers allocating them as needed. + ve := reflect.ValueOf(v.Interface()) + ve, err := d.indirect(ve) + if err != nil { + return 0, err + } + if !ve.CanSet() { + msg := fmt.Sprintf("can't decode to unsettable '%v'", + ve.Type().String()) + err := unmarshalError("decodeInterface", ErrNotSettable, msg, + nil, nil) + return 0, err + } + return d.decode(ve) +} + +// decode is the main workhorse for unmarshalling via reflection. It uses +// the passed reflection value to choose the XDR primitives to decode from +// the encapsulated reader. It is a recursive function, +// so cyclic data structures are not supported and will result in an infinite +// loop. It returns the the number of bytes actually read. +func (d *Decoder) decode(v reflect.Value) (int, error) { + if !v.IsValid() { + msg := fmt.Sprintf("type '%s' is not valid", v.Kind().String()) + err := unmarshalError("decode", ErrUnsupportedType, msg, nil, nil) + return 0, err + } + + // Indirect through pointers allocating them as needed. + ve, err := d.indirect(v) + if err != nil { + return 0, err + } + + // Handle time.Time values by decoding them as an RFC3339 formatted + // string with nanosecond precision. Check the type string rather + // than doing a full blown conversion to interface and type assertion + // since checking a string is much quicker. + switch ve.Type().String() { + case "time.Time": + // Read the value as a string and parse it. + timeString, n, err := d.DecodeString() + if err != nil { + return n, err + } + ttv, err := time.Parse(time.RFC3339, timeString) + if err != nil { + err := unmarshalError("decode", ErrParseTime, + err.Error(), timeString, err) + return n, err + } + ve.Set(reflect.ValueOf(ttv)) + return n, nil + } + // If this type is in our custom types map, call the decode routine set up + // for it. + if dt, ok := d.customTypes[ve.Type().String()]; ok { + return dt.Decode(d, v) + } + + // Handle native Go types. + switch ve.Kind() { + case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int: + i, n, err := d.DecodeInt() + if err != nil { + return n, err + } + if ve.OverflowInt(int64(i)) { + msg := fmt.Sprintf("signed integer too large to fit '%s'", + ve.Kind().String()) + err = unmarshalError("decode", ErrOverflow, msg, i, nil) + return n, err + } + ve.SetInt(int64(i)) + return n, nil + + case reflect.Int64: + i, n, err := d.DecodeHyper() + if err != nil { + return n, err + } + ve.SetInt(i) + return n, nil + + case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint: + ui, n, err := d.DecodeUint() + if err != nil { + return n, err + } + if ve.OverflowUint(uint64(ui)) { + msg := fmt.Sprintf("unsigned integer too large to fit '%s'", + ve.Kind().String()) + err = unmarshalError("decode", ErrOverflow, msg, ui, nil) + return n, err + } + ve.SetUint(uint64(ui)) + return n, nil + + case reflect.Uint64: + ui, n, err := d.DecodeUhyper() + if err != nil { + return n, err + } + ve.SetUint(ui) + return n, nil + + case reflect.Bool: + b, n, err := d.DecodeBool() + if err != nil { + return n, err + } + ve.SetBool(b) + return n, nil + + case reflect.Float32: + f, n, err := d.DecodeFloat() + if err != nil { + return n, err + } + ve.SetFloat(float64(f)) + return n, nil + + case reflect.Float64: + f, n, err := d.DecodeDouble() + if err != nil { + return n, err + } + ve.SetFloat(f) + return n, nil + + case reflect.String: + s, n, err := d.DecodeString() + if err != nil { + return n, err + } + ve.SetString(s) + return n, nil + + case reflect.Array: + n, err := d.decodeFixedArray(ve, false) + if err != nil { + return n, err + } + return n, nil + + case reflect.Slice: + n, err := d.decodeArray(ve, false) + if err != nil { + return n, err + } + return n, nil + + case reflect.Struct: + n, err := d.decodeStruct(ve) + if err != nil { + return n, err + } + return n, nil + + case reflect.Map: + n, err := d.decodeMap(ve) + if err != nil { + return n, err + } + return n, nil + + case reflect.Interface: + n, err := d.decodeInterface(ve) + if err != nil { + return n, err + } + return n, nil + } + + // The only unhandled types left are unsupported. At the time of this + // writing the only remaining unsupported types that exist are + // reflect.Uintptr and reflect.UnsafePointer. + msg := fmt.Sprintf("unsupported Go type '%s'", ve.Kind().String()) + err = unmarshalError("decode", ErrUnsupportedType, msg, nil, nil) + return 0, err +} + +// indirect dereferences pointers allocating them as needed until it reaches +// a non-pointer. This allows transparent decoding through arbitrary levels +// of indirection. +func (d *Decoder) indirect(v reflect.Value) (reflect.Value, error) { + rv := v + for rv.Kind() == reflect.Ptr { + // Allocate pointer if needed. + isNil := rv.IsNil() + if isNil && !rv.CanSet() { + msg := fmt.Sprintf("unable to allocate pointer for '%v'", + rv.Type().String()) + err := unmarshalError("indirect", ErrNotSettable, msg, + nil, nil) + return rv, err + } + if isNil { + rv.Set(reflect.New(rv.Type().Elem())) + } + rv = rv.Elem() + } + return rv, nil +} + +// Decode operates identically to the Unmarshal function with the exception of +// using the reader associated with the Decoder as the source of XDR-encoded +// data instead of a user-supplied reader. See the Unmarhsal documentation for +// specifics. +func (d *Decoder) Decode(v interface{}) (int, error) { + if v == nil { + msg := "can't unmarshal to nil interface" + return 0, unmarshalError("Unmarshal", ErrNilInterface, msg, nil, + nil) + } + + vv := reflect.ValueOf(v) + if vv.Kind() != reflect.Ptr { + msg := fmt.Sprintf("can't unmarshal to non-pointer '%v' - use "+ + "& operator", vv.Type().String()) + err := unmarshalError("Unmarshal", ErrBadArguments, msg, nil, nil) + return 0, err + } + if vv.IsNil() && !vv.CanSet() { + msg := fmt.Sprintf("can't unmarshal to unsettable '%v' - use "+ + "& operator", vv.Type().String()) + err := unmarshalError("Unmarshal", ErrNotSettable, msg, nil, nil) + return 0, err + } + + return d.decode(vv) +} + +// NewDecoder returns a Decoder that can be used to manually decode XDR data +// from a provided reader. Typically, Unmarshal should be used instead of +// manually creating a Decoder. +func NewDecoder(r io.Reader) *Decoder { + return &Decoder{r: r} +} + +// NewDecoderLimited is identical to NewDecoder but it sets maxReadSize in +// order to cap reads. +func NewDecoderLimited(r io.Reader, maxSize uint) *Decoder { + return &Decoder{r: r, maxReadSize: maxSize} +} + +// NewDecoderCustomTypes returns a decoder with support for custom types known +// to the caller. The second parameter is a map of the type name to the decoder +// routine. When the decoder finds a type matching one of the entries in the map +// it will call the custom routine for that type. +func NewDecoderCustomTypes(r io.Reader, maxSize uint, ct map[string]TypeDecoder) *Decoder { + return &Decoder{r: r, maxReadSize: maxSize, customTypes: ct} +} diff --git a/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/doc.go b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/doc.go new file mode 100644 index 000000000..8823d62f3 --- /dev/null +++ b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/doc.go @@ -0,0 +1,171 @@ +/* + * Copyright (c) 2012-2014 Dave Collins <dave@davec.name> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* +Package xdr implements the data representation portion of the External Data +Representation (XDR) standard protocol as specified in RFC 4506 (obsoletes +RFC 1832 and RFC 1014). + +The XDR RFC defines both a data specification language and a data +representation standard. This package implements methods to encode and decode +XDR data per the data representation standard with the exception of 128-bit +quadruple-precision floating points. It does not currently implement parsing of +the data specification language. In other words, the ability to automatically +generate Go code by parsing an XDR data specification file (typically .x +extension) is not supported. In practice, this limitation of the package is +fairly minor since it is largely unnecessary due to the reflection capabilities +of Go as described below. + +This package provides two approaches for encoding and decoding XDR data: + + 1) Marshal/Unmarshal functions which automatically map between XDR and Go types + 2) Individual Encoder/Decoder objects to manually work with XDR primitives + +For the Marshal/Unmarshal functions, Go reflection capabilities are used to +choose the type of the underlying XDR data based upon the Go type to encode or +the target Go type to decode into. A description of how each type is mapped is +provided below, however one important type worth reviewing is Go structs. In +the case of structs, each exported field (first letter capitalized) is reflected +and mapped in order. As a result, this means a Go struct with exported fields +of the appropriate types listed in the expected order can be used to +automatically encode / decode the XDR data thereby eliminating the need to write +a lot of boilerplate code to encode/decode and error check each piece of XDR +data as is typically required with C based XDR libraries. + +Go Type to XDR Type Mappings + +The following chart shows an overview of how Go types are mapped to XDR types +for automatic marshalling and unmarshalling. The documentation for the Marshal +and Unmarshal functions has specific details of how the mapping proceeds. + + Go Type <-> XDR Type + -------------------- + int8, int16, int32, int <-> XDR Integer + uint8, uint16, uint32, uint <-> XDR Unsigned Integer + int64 <-> XDR Hyper Integer + uint64 <-> XDR Unsigned Hyper Integer + bool <-> XDR Boolean + float32 <-> XDR Floating-Point + float64 <-> XDR Double-Precision Floating-Point + string <-> XDR String + byte <-> XDR Integer + []byte <-> XDR Variable-Length Opaque Data + [#]byte <-> XDR Fixed-Length Opaque Data + []<type> <-> XDR Variable-Length Array + [#]<type> <-> XDR Fixed-Length Array + struct <-> XDR Structure + map <-> XDR Variable-Length Array of two-element XDR Structures + time.Time <-> XDR String encoded with RFC3339 nanosecond precision + +Notes and Limitations: + + * Automatic marshalling and unmarshalling of variable and fixed-length + arrays of uint8s require a special struct tag `xdropaque:"false"` + since byte slices and byte arrays are assumed to be opaque data and + byte is a Go alias for uint8 thus indistinguishable under reflection + * Channel, complex, and function types cannot be encoded + * Interfaces without a concrete value cannot be encoded + * Cyclic data structures are not supported and will result in infinite + loops + * Strings are marshalled and unmarshalled with UTF-8 character encoding + which differs from the XDR specification of ASCII, however UTF-8 is + backwards compatible with ASCII so this should rarely cause issues + + +Encoding + +To encode XDR data, use the Marshal function. + func Marshal(w io.Writer, v interface{}) (int, error) + +For example, given the following code snippet: + + type ImageHeader struct { + Signature [3]byte + Version uint32 + IsGrayscale bool + NumSections uint32 + } + h := ImageHeader{[3]byte{0xAB, 0xCD, 0xEF}, 2, true, 10} + + var w bytes.Buffer + bytesWritten, err := xdr.Marshal(&w, &h) + // Error check elided + +The result, encodedData, will then contain the following XDR encoded byte +sequence: + + 0xAB, 0xCD, 0xEF, 0x00, + 0x00, 0x00, 0x00, 0x02, + 0x00, 0x00, 0x00, 0x01, + 0x00, 0x00, 0x00, 0x0A + + +In addition, while the automatic marshalling discussed above will work for the +vast majority of cases, an Encoder object is provided that can be used to +manually encode XDR primitives for complex scenarios where automatic +reflection-based encoding won't work. The included examples provide a sample of +manual usage via an Encoder. + + +Decoding + +To decode XDR data, use the Unmarshal function. + func Unmarshal(r io.Reader, v interface{}) (int, error) + +For example, given the following code snippet: + + type ImageHeader struct { + Signature [3]byte + Version uint32 + IsGrayscale bool + NumSections uint32 + } + + // Using output from the Encoding section above. + encodedData := []byte{ + 0xAB, 0xCD, 0xEF, 0x00, + 0x00, 0x00, 0x00, 0x02, + 0x00, 0x00, 0x00, 0x01, + 0x00, 0x00, 0x00, 0x0A, + } + + var h ImageHeader + bytesRead, err := xdr.Unmarshal(bytes.NewReader(encodedData), &h) + // Error check elided + +The struct instance, h, will then contain the following values: + + h.Signature = [3]byte{0xAB, 0xCD, 0xEF} + h.Version = 2 + h.IsGrayscale = true + h.NumSections = 10 + +In addition, while the automatic unmarshalling discussed above will work for the +vast majority of cases, a Decoder object is provided that can be used to +manually decode XDR primitives for complex scenarios where automatic +reflection-based decoding won't work. The included examples provide a sample of +manual usage via a Decoder. + +Errors + +All errors are either of type UnmarshalError or MarshalError. Both provide +human-readable output as well as an ErrorCode field which can be inspected by +sophisticated callers if necessary. + +See the documentation of UnmarshalError, MarshalError, and ErrorCode for further +details. +*/ +package xdr diff --git a/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/encode.go b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/encode.go new file mode 100644 index 000000000..7bac2681d --- /dev/null +++ b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/encode.go @@ -0,0 +1,669 @@ +/* + * Copyright (c) 2012-2014 Dave Collins <dave@davec.name> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +package xdr + +import ( + "fmt" + "io" + "math" + "reflect" + "time" +) + +var errIOEncode = "%s while encoding %d bytes" + +/* +Marshal writes the XDR encoding of v to writer w and returns the number of bytes +written. It traverses v recursively and automatically indirects pointers +through arbitrary depth to encode the actual value pointed to. + +Marshal uses reflection to determine the type of the concrete value contained by +v and performs a mapping of Go types to the underlying XDR types as follows: + + Go Type -> XDR Type + -------------------- + int8, int16, int32, int -> XDR Integer + uint8, uint16, uint32, uint -> XDR Unsigned Integer + int64 -> XDR Hyper Integer + uint64 -> XDR Unsigned Hyper Integer + bool -> XDR Boolean + float32 -> XDR Floating-Point + float64 -> XDR Double-Precision Floating-Point + string -> XDR String + byte -> XDR Integer + []byte -> XDR Variable-Length Opaque Data + [#]byte -> XDR Fixed-Length Opaque Data + []<type> -> XDR Variable-Length Array + [#]<type> -> XDR Fixed-Length Array + struct -> XDR Structure + map -> XDR Variable-Length Array of two-element XDR Structures + time.Time -> XDR String encoded with RFC3339 nanosecond precision + +Notes and Limitations: + + * Automatic marshalling of variable and fixed-length arrays of uint8s + requires a special struct tag `xdropaque:"false"` since byte slices and + byte arrays are assumed to be opaque data and byte is a Go alias for uint8 + thus indistinguishable under reflection + * Channel, complex, and function types cannot be encoded + * Interfaces without a concrete value cannot be encoded + * Cyclic data structures are not supported and will result in infinite loops + * Strings are marshalled with UTF-8 character encoding which differs from + the XDR specification of ASCII, however UTF-8 is backwards compatible with + ASCII so this should rarely cause issues + +If any issues are encountered during the marshalling process, a MarshalError is +returned with a human readable description as well as an ErrorCode value for +further inspection from sophisticated callers. Some potential issues are +unsupported Go types, attempting to encode more opaque data than can be +represented by a single opaque XDR entry, and exceeding max slice limitations. +*/ +func Marshal(w io.Writer, v interface{}) (int, error) { + enc := Encoder{w: w} + return enc.Encode(v) +} + +// An Encoder wraps an io.Writer that will receive the XDR encoded byte stream. +// See NewEncoder. +type Encoder struct { + w io.Writer +} + +// EncodeInt writes the XDR encoded representation of the passed 32-bit signed +// integer to the encapsulated writer and returns the number of bytes written. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.1 - Integer +// 32-bit big-endian signed integer in range [-2147483648, 2147483647] +func (enc *Encoder) EncodeInt(v int32) (int, error) { + var b [4]byte + b[0] = byte(v >> 24) + b[1] = byte(v >> 16) + b[2] = byte(v >> 8) + b[3] = byte(v) + + n, err := enc.w.Write(b[:]) + if err != nil { + msg := fmt.Sprintf(errIOEncode, err.Error(), 4) + err := marshalError("EncodeInt", ErrIO, msg, b[:n], err) + return n, err + } + + return n, nil +} + +// EncodeUint writes the XDR encoded representation of the passed 32-bit +// unsigned integer to the encapsulated writer and returns the number of bytes +// written. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.2 - Unsigned Integer +// 32-bit big-endian unsigned integer in range [0, 4294967295] +func (enc *Encoder) EncodeUint(v uint32) (int, error) { + var b [4]byte + b[0] = byte(v >> 24) + b[1] = byte(v >> 16) + b[2] = byte(v >> 8) + b[3] = byte(v) + + n, err := enc.w.Write(b[:]) + if err != nil { + msg := fmt.Sprintf(errIOEncode, err.Error(), 4) + err := marshalError("EncodeUint", ErrIO, msg, b[:n], err) + return n, err + } + + return n, nil +} + +// EncodeEnum treats the passed 32-bit signed integer as an enumeration value +// and, if it is in the list of passed valid enumeration values, writes the XDR +// encoded representation of it to the encapsulated writer. It returns the +// number of bytes written. +// +// A MarshalError is returned if the enumeration value is not one of the +// provided valid values or if writing the data fails. +// +// Reference: +// RFC Section 4.3 - Enumeration +// Represented as an XDR encoded signed integer +func (enc *Encoder) EncodeEnum(v int32, validEnums map[int32]bool) (int, error) { + if !validEnums[v] { + err := marshalError("EncodeEnum", ErrBadEnumValue, + "invalid enum", v, nil) + return 0, err + } + return enc.EncodeInt(v) +} + +// EncodeBool writes the XDR encoded representation of the passed boolean to the +// encapsulated writer and returns the number of bytes written. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.4 - Boolean +// Represented as an XDR encoded enumeration where 0 is false and 1 is true +func (enc *Encoder) EncodeBool(v bool) (int, error) { + i := int32(0) + if v == true { + i = 1 + } + return enc.EncodeInt(i) +} + +// EncodeHyper writes the XDR encoded representation of the passed 64-bit +// signed integer to the encapsulated writer and returns the number of bytes +// written. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.5 - Hyper Integer +// 64-bit big-endian signed integer in range [-9223372036854775808, 9223372036854775807] +func (enc *Encoder) EncodeHyper(v int64) (int, error) { + var b [8]byte + b[0] = byte(v >> 56) + b[1] = byte(v >> 48) + b[2] = byte(v >> 40) + b[3] = byte(v >> 32) + b[4] = byte(v >> 24) + b[5] = byte(v >> 16) + b[6] = byte(v >> 8) + b[7] = byte(v) + + n, err := enc.w.Write(b[:]) + if err != nil { + msg := fmt.Sprintf(errIOEncode, err.Error(), 8) + err := marshalError("EncodeHyper", ErrIO, msg, b[:n], err) + return n, err + } + + return n, nil +} + +// EncodeUhyper writes the XDR encoded representation of the passed 64-bit +// unsigned integer to the encapsulated writer and returns the number of bytes +// written. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.5 - Unsigned Hyper Integer +// 64-bit big-endian unsigned integer in range [0, 18446744073709551615] +func (enc *Encoder) EncodeUhyper(v uint64) (int, error) { + var b [8]byte + b[0] = byte(v >> 56) + b[1] = byte(v >> 48) + b[2] = byte(v >> 40) + b[3] = byte(v >> 32) + b[4] = byte(v >> 24) + b[5] = byte(v >> 16) + b[6] = byte(v >> 8) + b[7] = byte(v) + + n, err := enc.w.Write(b[:]) + if err != nil { + msg := fmt.Sprintf(errIOEncode, err.Error(), 8) + err := marshalError("EncodeUhyper", ErrIO, msg, b[:n], err) + return n, err + } + + return n, nil +} + +// EncodeFloat writes the XDR encoded representation of the passed 32-bit +// (single-precision) floating point to the encapsulated writer and returns the +// number of bytes written. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.6 - Floating Point +// 32-bit single-precision IEEE 754 floating point +func (enc *Encoder) EncodeFloat(v float32) (int, error) { + ui := math.Float32bits(v) + return enc.EncodeUint(ui) +} + +// EncodeDouble writes the XDR encoded representation of the passed 64-bit +// (double-precision) floating point to the encapsulated writer and returns the +// number of bytes written. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.7 - Double-Precision Floating Point +// 64-bit double-precision IEEE 754 floating point +func (enc *Encoder) EncodeDouble(v float64) (int, error) { + ui := math.Float64bits(v) + return enc.EncodeUhyper(ui) +} + +// RFC Section 4.8 - Quadruple-Precision Floating Point +// 128-bit quadruple-precision floating point +// Not Implemented + +// EncodeFixedOpaque treats the passed byte slice as opaque data of a fixed +// size and writes the XDR encoded representation of it to the encapsulated +// writer. It returns the number of bytes written. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.9 - Fixed-Length Opaque Data +// Fixed-length uninterpreted data zero-padded to a multiple of four +func (enc *Encoder) EncodeFixedOpaque(v []byte) (int, error) { + l := len(v) + pad := (4 - (l % 4)) % 4 + + // Write the actual bytes. + n, err := enc.w.Write(v) + if err != nil { + msg := fmt.Sprintf(errIOEncode, err.Error(), len(v)) + err := marshalError("EncodeFixedOpaque", ErrIO, msg, v[:n], err) + return n, err + } + + // Write any padding if needed. + if pad > 0 { + b := make([]byte, pad) + n2, err := enc.w.Write(b) + n += n2 + if err != nil { + written := make([]byte, l+n2) + copy(written, v) + copy(written[l:], b[:n2]) + msg := fmt.Sprintf(errIOEncode, err.Error(), l+pad) + err := marshalError("EncodeFixedOpaque", ErrIO, msg, + written, err) + return n, err + } + } + + return n, nil +} + +// EncodeOpaque treats the passed byte slice as opaque data of a variable +// size and writes the XDR encoded representation of it to the encapsulated +// writer. It returns the number of bytes written. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.10 - Variable-Length Opaque Data +// Unsigned integer length followed by fixed opaque data of that length +func (enc *Encoder) EncodeOpaque(v []byte) (int, error) { + // Length of opaque data. + n, err := enc.EncodeUint(uint32(len(v))) + if err != nil { + return n, err + } + + n2, err := enc.EncodeFixedOpaque(v) + n += n2 + return n, err +} + +// EncodeString writes the XDR encoded representation of the passed string +// to the encapsulated writer and returns the number of bytes written. +// Character encoding is assumed to be UTF-8 and therefore ASCII compatible. If +// the underlying character encoding is not compatible with this assumption, the +// data can instead be written as variable-length opaque data (EncodeOpaque) and +// manually converted as needed. +// +// A MarshalError with an error code of ErrIO is returned if writing the data +// fails. +// +// Reference: +// RFC Section 4.11 - String +// Unsigned integer length followed by bytes zero-padded to a multiple of four +func (enc *Encoder) EncodeString(v string) (int, error) { + // Length of string. + n, err := enc.EncodeUint(uint32(len(v))) + if err != nil { + return n, err + } + + n2, err := enc.EncodeFixedOpaque([]byte(v)) + n += n2 + return n, err +} + +// encodeFixedArray writes the XDR encoded representation of each element +// in the passed array represented by the reflection value to the encapsulated +// writer and returns the number of bytes written. The ignoreOpaque flag +// controls whether or not uint8 (byte) elements should be encoded individually +// or as a fixed sequence of opaque data. +// +// A MarshalError is returned if any issues are encountered while encoding +// the array elements. +// +// Reference: +// RFC Section 4.12 - Fixed-Length Array +// Individually XDR encoded array elements +func (enc *Encoder) encodeFixedArray(v reflect.Value, ignoreOpaque bool) (int, error) { + // Treat [#]byte (byte is alias for uint8) as opaque data unless ignored. + if !ignoreOpaque && v.Type().Elem().Kind() == reflect.Uint8 { + // Create a slice of the underlying array for better efficiency + // when possible. Can't create a slice of an unaddressable + // value. + if v.CanAddr() { + return enc.EncodeFixedOpaque(v.Slice(0, v.Len()).Bytes()) + } + + // When the underlying array isn't addressable fall back to + // copying the array into a new slice. This is rather ugly, but + // the inability to create a constant slice from an + // unaddressable array is a limitation of Go. + slice := make([]byte, v.Len(), v.Len()) + reflect.Copy(reflect.ValueOf(slice), v) + return enc.EncodeFixedOpaque(slice) + } + + // Encode each array element. + var n int + for i := 0; i < v.Len(); i++ { + n2, err := enc.encode(v.Index(i)) + n += n2 + if err != nil { + return n, err + } + } + + return n, nil +} + +// encodeArray writes an XDR encoded integer representing the number of +// elements in the passed slice represented by the reflection value followed by +// the XDR encoded representation of each element in slice to the encapsulated +// writer and returns the number of bytes written. The ignoreOpaque flag +// controls whether or not uint8 (byte) elements should be encoded individually +// or as a variable sequence of opaque data. +// +// A MarshalError is returned if any issues are encountered while encoding +// the array elements. +// +// Reference: +// RFC Section 4.13 - Variable-Length Array +// Unsigned integer length followed by individually XDR encoded array elements +func (enc *Encoder) encodeArray(v reflect.Value, ignoreOpaque bool) (int, error) { + numItems := uint32(v.Len()) + n, err := enc.EncodeUint(numItems) + if err != nil { + return n, err + } + + n2, err := enc.encodeFixedArray(v, ignoreOpaque) + n += n2 + return n, err +} + +// encodeStruct writes an XDR encoded representation of each value in the +// exported fields of the struct represented by the passed reflection value to +// the encapsulated writer and returns the number of bytes written. Pointers +// are automatically indirected through arbitrary depth to encode the actual +// value pointed to. +// +// A MarshalError is returned if any issues are encountered while encoding +// the elements. +// +// Reference: +// RFC Section 4.14 - Structure +// XDR encoded elements in the order of their declaration in the struct +func (enc *Encoder) encodeStruct(v reflect.Value) (int, error) { + var n int + vt := v.Type() + for i := 0; i < v.NumField(); i++ { + // Skip unexported fields and indirect through pointers. + vtf := vt.Field(i) + if vtf.PkgPath != "" { + continue + } + vf := v.Field(i) + vf = enc.indirect(vf) + + // Handle non-opaque data to []uint8 and [#]uint8 based on struct tag. + tag := vtf.Tag.Get("xdropaque") + if tag == "false" { + switch vf.Kind() { + case reflect.Slice: + n2, err := enc.encodeArray(vf, true) + n += n2 + if err != nil { + return n, err + } + continue + + case reflect.Array: + n2, err := enc.encodeFixedArray(vf, true) + n += n2 + if err != nil { + return n, err + } + continue + } + } + + // Encode each struct field. + n2, err := enc.encode(vf) + n += n2 + if err != nil { + return n, err + } + } + + return n, nil +} + +// RFC Section 4.15 - Discriminated Union +// RFC Section 4.16 - Void +// RFC Section 4.17 - Constant +// RFC Section 4.18 - Typedef +// RFC Section 4.19 - Optional data +// RFC Sections 4.15 though 4.19 only apply to the data specification language +// which is not implemented by this package. In the case of discriminated +// unions, struct tags are used to perform a similar function. + +// encodeMap treats the map represented by the passed reflection value as a +// variable-length array of 2-element structures whose fields are of the same +// type as the map keys and elements and writes its XDR encoded representation +// to the encapsulated writer. It returns the number of bytes written. +// +// A MarshalError is returned if any issues are encountered while encoding +// the elements. +func (enc *Encoder) encodeMap(v reflect.Value) (int, error) { + // Number of elements. + n, err := enc.EncodeUint(uint32(v.Len())) + if err != nil { + return n, err + } + + // Encode each key and value according to their type. + for _, key := range v.MapKeys() { + n2, err := enc.encode(key) + n += n2 + if err != nil { + return n, err + } + + n2, err = enc.encode(v.MapIndex(key)) + n += n2 + if err != nil { + return n, err + } + } + + return n, nil +} + +// encodeInterface examines the interface represented by the passed reflection +// value to detect whether it is an interface that can be encoded if it is, +// extracts the underlying value to pass back into the encode function for +// encoding according to its type. +// +// A MarshalError is returned if any issues are encountered while encoding +// the interface. +func (enc *Encoder) encodeInterface(v reflect.Value) (int, error) { + if v.IsNil() || !v.CanInterface() { + msg := fmt.Sprintf("can't encode nil interface") + err := marshalError("encodeInterface", ErrNilInterface, msg, + nil, nil) + return 0, err + } + + // Extract underlying value from the interface and indirect through pointers. + ve := reflect.ValueOf(v.Interface()) + ve = enc.indirect(ve) + return enc.encode(ve) +} + +// encode is the main workhorse for marshalling via reflection. It uses +// the passed reflection value to choose the XDR primitives to encode into +// the encapsulated writer and returns the number of bytes written. It is a +// recursive function, so cyclic data structures are not supported and will +// result in an infinite loop. +func (enc *Encoder) encode(v reflect.Value) (int, error) { + if !v.IsValid() { + msg := fmt.Sprintf("type '%s' is not valid", v.Kind().String()) + err := marshalError("encode", ErrUnsupportedType, msg, nil, nil) + return 0, err + } + + // Indirect through pointers to get at the concrete value. + ve := enc.indirect(v) + + // Handle time.Time values by encoding them as an RFC3339 formatted + // string with nanosecond precision. Check the type string before + // doing a full blown conversion to interface and type assertion since + // checking a string is much quicker. + if ve.Type().String() == "time.Time" && ve.CanInterface() { + viface := ve.Interface() + if tv, ok := viface.(time.Time); ok { + return enc.EncodeString(tv.Format(time.RFC3339Nano)) + } + } + + // Handle native Go types. + switch ve.Kind() { + case reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int: + return enc.EncodeInt(int32(ve.Int())) + + case reflect.Int64: + return enc.EncodeHyper(ve.Int()) + + case reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint: + return enc.EncodeUint(uint32(ve.Uint())) + + case reflect.Uint64: + return enc.EncodeUhyper(ve.Uint()) + + case reflect.Bool: + return enc.EncodeBool(ve.Bool()) + + case reflect.Float32: + return enc.EncodeFloat(float32(ve.Float())) + + case reflect.Float64: + return enc.EncodeDouble(ve.Float()) + + case reflect.String: + return enc.EncodeString(ve.String()) + + case reflect.Array: + return enc.encodeFixedArray(ve, false) + + case reflect.Slice: + return enc.encodeArray(ve, false) + + case reflect.Struct: + return enc.encodeStruct(ve) + + case reflect.Map: + return enc.encodeMap(ve) + + case reflect.Interface: + return enc.encodeInterface(ve) + } + + // The only unhandled types left are unsupported. At the time of this + // writing the only remaining unsupported types that exist are + // reflect.Uintptr and reflect.UnsafePointer. + msg := fmt.Sprintf("unsupported Go type '%s'", ve.Kind().String()) + err := marshalError("encode", ErrUnsupportedType, msg, nil, nil) + return 0, err +} + +// indirect dereferences pointers until it reaches a non-pointer. This allows +// transparent encoding through arbitrary levels of indirection. +func (enc *Encoder) indirect(v reflect.Value) reflect.Value { + rv := v + for rv.Kind() == reflect.Ptr { + rv = rv.Elem() + } + return rv +} + +// Encode operates identically to the Marshal function with the exception of +// using the writer associated with the Encoder for the destination of the +// XDR-encoded data instead of a user-supplied writer. See the Marshal +// documentation for specifics. +func (enc *Encoder) Encode(v interface{}) (int, error) { + if v == nil { + msg := "can't marshal nil interface" + err := marshalError("Marshal", ErrNilInterface, msg, nil, nil) + return 0, err + } + + vv := reflect.ValueOf(v) + vve := vv + for vve.Kind() == reflect.Ptr { + if vve.IsNil() { + msg := fmt.Sprintf("can't marshal nil pointer '%v'", + vv.Type().String()) + err := marshalError("Marshal", ErrBadArguments, msg, + nil, nil) + return 0, err + } + vve = vve.Elem() + } + + return enc.encode(vve) +} + +// NewEncoder returns an object that can be used to manually choose fields to +// XDR encode to the passed writer w. Typically, Marshal should be used instead +// of manually creating an Encoder. An Encoder, along with several of its +// methods to encode XDR primitives, is exposed so it is possible to perform +// manual encoding of data without relying on reflection should it be necessary +// in complex scenarios where automatic reflection-based encoding won't work. +func NewEncoder(w io.Writer) *Encoder { + return &Encoder{w: w} +} diff --git a/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/error.go b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/error.go new file mode 100644 index 000000000..42079ad35 --- /dev/null +++ b/vendor/github.com/digitalocean/go-libvirt/internal/go-xdr/xdr2/error.go @@ -0,0 +1,177 @@ +/* + * Copyright (c) 2012-2014 Dave Collins <dave@davec.name> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +package xdr + +import "fmt" + +// ErrorCode identifies a kind of error. +type ErrorCode int + +const ( + // ErrBadArguments indicates arguments passed to the function are not + // what was expected. + ErrBadArguments ErrorCode = iota + + // ErrUnsupportedType indicates the Go type is not a supported type for + // marshalling and unmarshalling XDR data. + ErrUnsupportedType + + // ErrBadEnumValue indicates an enumeration value is not in the list of + // valid values. + ErrBadEnumValue + + // ErrNotSettable indicates an interface value cannot be written to. + // This usually means the interface value was not passed with the & + // operator, but it can also happen if automatic pointer allocation + // fails. + ErrNotSettable + + // ErrOverflow indicates that the data in question is too large to fit + // into the corresponding Go or XDR data type. For example, an integer + // decoded from XDR that is too large to fit into a target type of int8, + // or opaque data that exceeds the max length of a Go slice. + ErrOverflow + + // ErrNilInterface indicates an interface with no concrete type + // information was encountered. Type information is necessary to + // perform mapping between XDR and Go types. + ErrNilInterface + + // ErrIO indicates an error was encountered while reading or writing to + // an io.Reader or io.Writer, respectively. The actual underlying error + // will be available via the Err field of the MarshalError or + // UnmarshalError struct. + ErrIO + + // ErrParseTime indicates an error was encountered while parsing an + // RFC3339 formatted time value. The actual underlying error will be + // available via the Err field of the UnmarshalError struct. + ErrParseTime +) + +// Map of ErrorCode values back to their constant names for pretty printing. +var errorCodeStrings = map[ErrorCode]string{ + ErrBadArguments: "ErrBadArguments", + ErrUnsupportedType: "ErrUnsupportedType", + ErrBadEnumValue: "ErrBadEnumValue", + ErrNotSettable: "ErrNotSettable", + ErrOverflow: "ErrOverflow", + ErrNilInterface: "ErrNilInterface", + ErrIO: "ErrIO", + ErrParseTime: "ErrParseTime", +} + +// String returns the ErrorCode as a human-readable name. +func (e ErrorCode) String() string { + if s := errorCodeStrings[e]; s != "" { + return s + } + return fmt.Sprintf("Unknown ErrorCode (%d)", e) +} + +// UnmarshalError describes a problem encountered while unmarshaling data. +// Some potential issues are unsupported Go types, attempting to decode a value +// which is too large to fit into a specified Go type, and exceeding max slice +// limitations. +type UnmarshalError struct { + ErrorCode ErrorCode // Describes the kind of error + Func string // Function name + Value interface{} // Value actually parsed where appropriate + Description string // Human readable description of the issue + Err error // The underlying error for IO errors +} + +// Error satisfies the error interface and prints human-readable errors. +func (e *UnmarshalError) Error() string { + switch e.ErrorCode { + case ErrBadEnumValue, ErrOverflow, ErrIO, ErrParseTime: + return fmt.Sprintf("xdr:%s: %s - read: '%v'", e.Func, + e.Description, e.Value) + } + return fmt.Sprintf("xdr:%s: %s", e.Func, e.Description) +} + +// unmarshalError creates an error given a set of arguments and will copy byte +// slices into the Value field since they might otherwise be changed from from +// the original value. +func unmarshalError(f string, c ErrorCode, desc string, v interface{}, err error) *UnmarshalError { + e := &UnmarshalError{ErrorCode: c, Func: f, Description: desc, Err: err} + switch t := v.(type) { + case []byte: + slice := make([]byte, len(t)) + copy(slice, t) + e.Value = slice + default: + e.Value = v + } + + return e +} + +// IsIO returns a boolean indicating whether the error is known to report that +// the underlying reader or writer encountered an ErrIO. +func IsIO(err error) bool { + switch e := err.(type) { + case *UnmarshalError: + return e.ErrorCode == ErrIO + case *MarshalError: + return e.ErrorCode == ErrIO + } + return false +} + +// MarshalError describes a problem encountered while marshaling data. +// Some potential issues are unsupported Go types, attempting to encode more +// opaque data than can be represented by a single opaque XDR entry, and +// exceeding max slice limitations. +type MarshalError struct { + ErrorCode ErrorCode // Describes the kind of error + Func string // Function name + Value interface{} // Value actually parsed where appropriate + Description string // Human readable description of the issue + Err error // The underlying error for IO errors +} + +// Error satisfies the error interface and prints human-readable errors. +func (e *MarshalError) Error() string { + switch e.ErrorCode { + case ErrIO: + return fmt.Sprintf("xdr:%s: %s - wrote: '%v'", e.Func, + e.Description, e.Value) + case ErrBadEnumValue: + return fmt.Sprintf("xdr:%s: %s - value: '%v'", e.Func, + e.Description, e.Value) + } + return fmt.Sprintf("xdr:%s: %s", e.Func, e.Description) +} + +// marshalError creates an error given a set of arguments and will copy byte +// slices into the Value field since they might otherwise be changed from from +// the original value. +func marshalError(f string, c ErrorCode, desc string, v interface{}, err error) *MarshalError { + e := &MarshalError{ErrorCode: c, Func: f, Description: desc, Err: err} + switch t := v.(type) { + case []byte: + slice := make([]byte, len(t)) + copy(slice, t) + e.Value = slice + default: + e.Value = v + } + + return e +} |