mirror of
https://github.com/beego/bee.git
synced 2024-11-05 11:50:55 +00:00
147 lines
3.9 KiB
Go
147 lines
3.9 KiB
Go
// Copyright 2014 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package macho
|
|
|
|
import (
|
|
"encoding/binary"
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
)
|
|
|
|
// A FatFile is a Mach-O universal binary that contains at least one architecture.
|
|
type FatFile struct {
|
|
Magic uint32
|
|
Arches []FatArch
|
|
closer io.Closer
|
|
}
|
|
|
|
// A FatArchHeader represents a fat header for a specific image architecture.
|
|
type FatArchHeader struct {
|
|
Cpu Cpu
|
|
SubCpu uint32
|
|
Offset uint32
|
|
Size uint32
|
|
Align uint32
|
|
}
|
|
|
|
const fatArchHeaderSize = 5 * 4
|
|
|
|
// A FatArch is a Mach-O File inside a FatFile.
|
|
type FatArch struct {
|
|
FatArchHeader
|
|
*File
|
|
}
|
|
|
|
// ErrNotFat is returned from NewFatFile or OpenFat when the file is not a
|
|
// universal binary but may be a thin binary, based on its magic number.
|
|
var ErrNotFat = &FormatError{0, "not a fat Mach-O file", nil}
|
|
|
|
// NewFatFile creates a new FatFile for accessing all the Mach-O images in a
|
|
// universal binary. The Mach-O binary is expected to start at position 0 in
|
|
// the ReaderAt.
|
|
func NewFatFile(r io.ReaderAt) (*FatFile, error) {
|
|
var ff FatFile
|
|
sr := io.NewSectionReader(r, 0, 1<<63-1)
|
|
|
|
// Read the fat_header struct, which is always in big endian.
|
|
// Start with the magic number.
|
|
err := binary.Read(sr, binary.BigEndian, &ff.Magic)
|
|
if err != nil {
|
|
return nil, &FormatError{0, "error reading magic number", nil}
|
|
} else if ff.Magic != MagicFat {
|
|
// See if this is a Mach-O file via its magic number. The magic
|
|
// must be converted to little endian first though.
|
|
var buf [4]byte
|
|
binary.BigEndian.PutUint32(buf[:], ff.Magic)
|
|
leMagic := binary.LittleEndian.Uint32(buf[:])
|
|
if leMagic == Magic32 || leMagic == Magic64 {
|
|
return nil, ErrNotFat
|
|
} else {
|
|
return nil, &FormatError{0, "invalid magic number", nil}
|
|
}
|
|
}
|
|
offset := int64(4)
|
|
|
|
// Read the number of FatArchHeaders that come after the fat_header.
|
|
var narch uint32
|
|
err = binary.Read(sr, binary.BigEndian, &narch)
|
|
if err != nil {
|
|
return nil, &FormatError{offset, "invalid fat_header", nil}
|
|
}
|
|
offset += 4
|
|
|
|
if narch < 1 {
|
|
return nil, &FormatError{offset, "file contains no images", nil}
|
|
}
|
|
|
|
// Combine the Cpu and SubCpu (both uint32) into a uint64 to make sure
|
|
// there are not duplicate architectures.
|
|
seenArches := make(map[uint64]bool, narch)
|
|
// Make sure that all images are for the same MH_ type.
|
|
var machoType Type
|
|
|
|
// Following the fat_header comes narch fat_arch structs that index
|
|
// Mach-O images further in the file.
|
|
ff.Arches = make([]FatArch, narch)
|
|
for i := uint32(0); i < narch; i++ {
|
|
fa := &ff.Arches[i]
|
|
err = binary.Read(sr, binary.BigEndian, &fa.FatArchHeader)
|
|
if err != nil {
|
|
return nil, &FormatError{offset, "invalid fat_arch header", nil}
|
|
}
|
|
offset += fatArchHeaderSize
|
|
|
|
fr := io.NewSectionReader(r, int64(fa.Offset), int64(fa.Size))
|
|
fa.File, err = NewFile(fr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
// Make sure the architecture for this image is not duplicate.
|
|
seenArch := (uint64(fa.Cpu) << 32) | uint64(fa.SubCpu)
|
|
if o, k := seenArches[seenArch]; o || k {
|
|
return nil, &FormatError{offset, fmt.Sprintf("duplicate architecture cpu=%v, subcpu=%#x", fa.Cpu, fa.SubCpu), nil}
|
|
}
|
|
seenArches[seenArch] = true
|
|
|
|
// Make sure the Mach-O type matches that of the first image.
|
|
if i == 0 {
|
|
machoType = fa.Type
|
|
} else {
|
|
if fa.Type != machoType {
|
|
return nil, &FormatError{offset, fmt.Sprintf("Mach-O type for architecture #%d (type=%#x) does not match first (type=%#x)", i, fa.Type, machoType), nil}
|
|
}
|
|
}
|
|
}
|
|
|
|
return &ff, nil
|
|
}
|
|
|
|
// OpenFat opens the named file using os.Open and prepares it for use as a Mach-O
|
|
// universal binary.
|
|
func OpenFat(name string) (ff *FatFile, err error) {
|
|
f, err := os.Open(name)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
ff, err = NewFatFile(f)
|
|
if err != nil {
|
|
f.Close()
|
|
return nil, err
|
|
}
|
|
ff.closer = f
|
|
return
|
|
}
|
|
|
|
func (ff *FatFile) Close() error {
|
|
var err error
|
|
if ff.closer != nil {
|
|
err = ff.closer.Close()
|
|
ff.closer = nil
|
|
}
|
|
return err
|
|
}
|