Caleb Gardner
127 lines
3.3 KiB
Go
127 lines
3.3 KiB
Go
package squashfs
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//The types of compression supported by squashfs.
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const (
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GzipCompression = 1 + iota
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LzmaCompression
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LzoCompression
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XzCompression
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Lz4Compression
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ZstdCompression
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)
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//Superblock contains important information about a squashfs file. Located at the very front of the archive.
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type superblock struct {
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Magic uint32
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InodeCount uint32
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CreationTime uint32
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BlockSize uint32
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FragCount uint32
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CompressionType uint16
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BlockLog uint16
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Flags uint16
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IDCount uint16
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MajorVersion uint16
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MinorVersion uint16
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RootInodeRef uint64
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BytesUsed uint64
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IDTableStart uint64
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XattrTableStart uint64
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InodeTableStart uint64
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DirTableStart uint64
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FragTableStart uint64
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ExportTableStart uint64
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}
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//SuperblockFlags is the series of flags describing how a squashfs archive is packed.
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type SuperblockFlags struct {
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//If true, inodes are stored uncompressed.
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UncompressedInodes bool
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//If true, data is stored uncompressed.
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UncompressedData bool
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check bool
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//If true, fragments are stored uncompressed.
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UncompressedFragments bool
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//If true, ALL data is stored in sequential data blocks instead of utilizing fragments.
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NoFragments bool
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//If true, the last block of data will always be stored as a fragment if it's less then the block size.
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AlwaysFragment bool
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//If true, duplicate files are only stored once. (Currently unsupported)
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RemoveDuplicates bool
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//If true, the export table is populated. (Currently unsupported)
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Exportable bool
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//If true, the xattr table is uncompressed. (Currently unsupported)
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UncompressedXattr bool
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//If true, the xattr table is not populated. (Currently unsupported)
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NoXattr bool
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compressorOptions bool
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//If true, the UID/GID table is stored uncompressed.
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UncompressedIDs bool
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}
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//DefaultFlags are the default SuperblockFlags that are used.
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var DefaultFlags = SuperblockFlags{
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RemoveDuplicates: true,
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Exportable: true,
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}
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//GetFlags returns a SuperblockFlags for a given superblock.
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func (s *superblock) GetFlags() SuperblockFlags {
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return SuperblockFlags{
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UncompressedInodes: s.Flags&0x1 == 0x1,
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UncompressedData: s.Flags&0x2 == 0x2,
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check: s.Flags&0x4 == 0x4,
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UncompressedFragments: s.Flags&0x8 == 0x8,
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NoFragments: s.Flags&0x10 == 0x10,
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AlwaysFragment: s.Flags&0x20 == 0x20,
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RemoveDuplicates: s.Flags&0x40 == 0x40,
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Exportable: s.Flags&0x80 == 0x80,
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UncompressedXattr: s.Flags&0x100 == 0x100,
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NoXattr: s.Flags&0x200 == 0x200,
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compressorOptions: s.Flags&0x400 == 0x400,
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UncompressedIDs: s.Flags&0x800 == 0x800,
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}
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}
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//ToUint returns the uint16 representation of the given SuperblockFlags
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func (s *SuperblockFlags) ToUint() uint16 {
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var out uint16
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if s.UncompressedInodes {
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out = out | 0x1
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}
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if s.UncompressedData {
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out = out | 0x2
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}
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if s.check {
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out = out | 0x4
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}
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if s.UncompressedFragments {
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out = out | 0x8
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}
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if s.NoFragments {
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out = out | 0x10
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}
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if s.AlwaysFragment {
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out = out | 0x20
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}
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if s.RemoveDuplicates {
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out = out | 0x40
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}
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if s.Exportable {
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out = out | 0x80
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}
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if s.UncompressedXattr {
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out = out | 0x100
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}
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if s.NoXattr {
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out = out | 0x200
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}
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if s.compressorOptions {
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out = out | 0x400
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}
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if s.UncompressedIDs {
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out = out | 0x800
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}
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return out
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}
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