74 lines
1.5 KiB
Go
74 lines
1.5 KiB
Go
package firmware
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"github.com/go-playground/log/v7"
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"hash/crc32"
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"io"
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"io/ioutil"
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"os"
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"path"
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)
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// FwExists check if file exists
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func FwExists(path string) bool {
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_, err := os.Stat(path)
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return !errors.Is(err, os.ErrNotExist)
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}
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// ChkHeader: runs header and CRC checks on the firmware file
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func ChkHeader(fwfile string) error {
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log.Info("checking ", fwfile)
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// SCS has two different file layouts, one for the "Dragons", the other for any older modem
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var offset uint32
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if path.Ext(fwfile) == ".dr7" {
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offset = 0
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} else {
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offset = 4
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}
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r, err := os.Open(fwfile)
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if err != nil {
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return err
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}
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defer r.Close()
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var header [2]byte
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_, err = io.ReadFull(r, header[:])
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if err != nil {
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return err
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}
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if offset == 0 {
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if header != [2]byte{0x50, 0x34} {
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return errors.New("ERROR: wrong firmware header")
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}
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} else {
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if header != [2]byte{0x60, 0xea} {
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return errors.New("ERROR: wrong firmware header")
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}
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}
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r.Close()
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firmware, err := ioutil.ReadFile(fwfile)
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if err != nil {
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return errors.New("ERROR: ReadFile operation failed")
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}
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var size uint32
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if offset == 0 {
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size = binary.LittleEndian.Uint32(firmware[4:8]) // Dragons
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} else {
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size = uint32(binary.LittleEndian.Uint16(firmware[2:4])) // PTC-3 and Co
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}
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a := make([]byte, 4)
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binary.LittleEndian.PutUint32(a, crc32.ChecksumIEEE(firmware[offset:offset+size]))
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if bytes.Equal(a, firmware[offset+size:offset+size+4]) {
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log.Info("CRC checksum ok!")
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} else {
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return errors.New("CRC checksum NOT ok!")
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}
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return nil
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}
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