43 lines
4.2 KiB
Markdown
43 lines
4.2 KiB
Markdown
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---
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title: "ustar.h"
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summary: "specific driver for USTAR"
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---
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**Warning:** This is a filesystem specific driver, by this it should only be accessed by the [vfs](https://nerdcult.net/projects/noxos/docs/codebase/drivers/fs/vfs.h/).
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The USTAR '_filesystem_' is probably more common known as **tar**-archive.
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It is a really simple concept, where a file consists of a header block followed by data blocks.
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These blocks are aligned at 512 bytes.
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OSDev Wiki: [USTAR](https://wiki.osdev.org/USTAR)
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# `ustar_type_E` - enum
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The types an entry can have:
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- **File**
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- **Hardlink**
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- **Symlink**
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- **Char Device**
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- **Block Device**
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- **Directory**
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- **Pipe**
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# `ustar_header_T` - struct [packed / 512B aligned]
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| Name | Type | Description |
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|-------------------|-----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| name | char[100] | The name of the entry |
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| mode | uint64_t | file mode (permissions, etc) |
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| owner_id | uint64_t | The owners ID |
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| group_id | uint64_t | The groups ID |
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| size | char[12] | The size of the entry, represented as a string of an octal number (dafuq) |
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| last_modification | char[12] | The unix-timestamp, when the entry was modified the last time |
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| checksum | uint64_t | I think this is a weird checksum of the header |
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| type | uint8_t | The [ustar_type_E](https://nerdcult.net/projects/noxos/docs/codebase/drivers/fs/ustar.h/#ustar_type_e---enum) of the entry, represented as ascii numbers (dafuq) |
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| name_linked | char[100] | The path to the linked entry, if this is a link-entry |
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| indicator | char[6] | This needs to be `ustar` |
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| version | uint16_t | The version of the **tar** command, that created the archive |
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| owner_user_name | char[32] | The name of the file owner |
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| owner_group_name | char[32] | The name of the file group |
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| device_major | uint64_t | The devices major number |
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| device_minor | uint64_t | The devices minor number |
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| name_prefix | char[155] | If this is not null, this acts as a prefix for _name_ |
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