# SFTP Protocol v6 Quick reference tables

<style>
.markdown-body table {
font-size: 1.2rem;
margin: auto;
width: fit-content;
}
.markdown-body td {
font-family: monospace;
}
</style>

# &sect;4.3: Packet types

|name |value |hex |
|----------------------|-----:|---:|
|SSH_FXP_INIT |1 |0x01|
|SSH_FXP_VERSION |2 |0x02|
|SSH_FXP_OPEN |3 |0x03|
|SSH_FXP_CLOSE |4 |0x04|
|SSH_FXP_READ |5 |0x05|
|SSH_FXP_WRITE |6 |0x06|
|SSH_FXP_LSTAT |7 |0x07|
|SSH_FXP_FSTAT |8 |0x08|
|SSH_FXP_SETSTAT |9 |0x09|
|SSH_FXP_FSETSTAT |10 |0x0A|
|SSH_FXP_OPENDIR |11 |0x0B|
|SSH_FXP_READDIR |12 |0x0C|
|SSH_FXP_REMOVE |13 |0x0D|
|SSH_FXP_MKDIR |14 |0x0E|
|SSH_FXP_RMDIR |15 |0x0F|
|SSH_FXP_REALPATH |16 |0x10|
|SSH_FXP_STAT |17 |0x11|
|SSH_FXP_RENAME |18 |0x12|
|SSH_FXP_READLINK |19 |0x13|
|\-\-\- |20 |0x14|
|SSH_FXP_LINK |21 |0x15|
|SSH_FXP_BLOCK |22 |0x16|
|SSH_FXP_UNBLOCK |23 |0x17|
| | | |
|SSH_FXP_STATUS |101 |0x65|
|SSH_FXP_HANDLE |102 |0x66|
|SSH_FXP_DATA |103 |0x67|
|SSH_FXP_NAME |104 |0x68|
|SSH_FXP_ATTRS |105 |0x69|
| | | |
|SSH_FXP_EXTENDED |200 |0xC8|
|SSH_FXP_EXTENDED_REPLY|201 |0xC9|

# &sect;7: File attributes

| `SSH_FILEXFER...` | hex |
|------------------------|---------:|
|~_ATTR_SIZE | 0x0001|
|\-\-\- (deprecated) | 0x0002|
|~_ATTR_PERMISSIONS | 0x0004|
|~_ATTR_ACCESSTIME | 0x0008|
|~_ATTR_CREATETIME | 0x0010|
|~_ATTR_MODIFYTIME | 0x0020|
|~_ATTR_ACL | 0x0040|
|~_ATTR_OWNERGROUP | 0x0080|
|~_ATTR_SUBSECOND_TIMES | 0x0100|
|~_ATTR_BITS | 0x0200|
|~_ATTR_ALLOCATION_SIZE | 0x0400|
|~_ATTR_TEXT_HINT | 0x0800|
|~_ATTR_MIME_TYPE | 0x1000|
|~_ATTR_LINK_COUNT | 0x2000|
|~_ATTR_UNTRANSLATED_NAME| 0x4000|
|~_ATTR_CTIME | 0x8000|
|~_ATTR_EXTENDED |0x80000000|

## Support table

|type |attr |supported by |mask |
|--------|------------------------|------------------|---------:|
|uint32 |valid-attribute-flags | (always present) | |
|byte |type | (always present) | |
|uint64 |size |SIZE | 0x0001|
|uint64 |allocation-size |ALLOCATION | 0x0400|
|string |owner |OWNERGROUP | 0x0080|
|string |group |OWNERGROUP | 0x0080|
|uint32 |permissions |PERMISSIONS | 0x0004|
|int64 |atime |MODIFIED | 0x0008|
|uint32 |atime-nseconds |SUBSECOND_TIMES | 0x0108|
|int64 |createtime |CREATETIME | 0x0010|
|uint32 |createtime-nseconds |SUBSECOND_TIMES | 0x0110|
|int64 |mtime |ACMODTIME | 0x0020|
|uint32 |mtime-nseconds |SUBSECOND_TIMES | 0x0120|
|int64 |ctime |CTIME | 0x8000|
|uint32 |ctime-nseconds |SUBSECOND_TIMES | 0x8010|
|string |acl |ACL | 0x0040|
|uint32 |attrib-bits |BITS | 0x0200|
|uint32 |attrib-bits-valid |BITS | 0x0200|
|byte |text-hint |TEXT_HINT | 0x0800|
|string |mime-type |MIME_TYPE | 0x1000|
|uint32 |link-count |LINK_COUNT | 0x2000|
|string |untranslated-name |UNTRANSLATED_NAME | 0x4000|
|uint32 |extended-count |EXTENDED |0x80000000|

<br>

**supported by** field means that the field only presents if `valid-attribute-flags` has the bit set indicated by `SSH_FILEXFER_...`, as shown in the **mask** column for reference. Otherwise, the field is skipped.

**Note on owner/group information**: In SFTP v3, owners and groups were reported by uid/gid. v6 no longer supports the flag `SSH_FILEXFER_UIDGID`, and can only report owner or group by names. Refer to the spec of v6:

> 0x00000002 was used in a previous version of this protocol. It is now a reserved value and MUST NOT appear in the mask. Some future version of this protocol may reuse this value.

... where 0x00000002 is actually the `SSH_FILEXFER_UIDGID` in SFTP v3.

To be compatible with most interfaces (POSIX?), v6 clients must come up a way mapping those strings back to ids.

**Nanosecond fields**: Special cases are `*-nseconds` where one also requires the presence of flag supporting its timestamp (in seconds). The specification did not make it clear enough, and some client might exhabit nonsensical behavior.

As a side note, the flags [Green End SFTP Server](https://www.greenend.org.uk/rjk/sftpserver/) supply to its client for SFTP v6 is `0xA3AD`.

# &sect;7.2 File types

|`SSH_FILEXFER_TYPE...`|value|st_mode |hex |meaning |
|----------------------|----:|--------|-------:|----------------|
|~_REGULAR | 1|S_IFREG | 0x8000|regular file |
|~_DIRECTORY | 2|S_IFDIR | 0x4000|directory |
|~_SYMLINK | 3|S_IFLNK | 0xA000|symbolic link |
|~_SPECIAL | 4| (N/A) | | |
|~_UNKNOWN | 5| (N/A) | | |
|~_SOCKET | 6|S_IFSOCK| 0xC000|socket |
|~_CHAR_DEVICE | 7|S_IFCHR | 0x2000|character device|
|~_BLOCK_DEVICE | 8|S_IFBLK | 0x6000|block device |
|~_FIFO | 9|S_IFIFO | 0x1000|FIFO |

<br>

The enums of `st_mode` are referred from [the manpage](https://man7.org/linux/man-pages/man3/stat.3type.html). As a small hack, GE stores the entire `st_mode` of an inode in the `permissions` field, so you don't have to map it if you know the server is a GE one.

# &sect;7.9 File attrib-bits

(WIP)

|`SSH_FILEXFER_ATTR_FLAGS...`|value|
|----------------------------|----:|
|~_READONLY |0x0001|
|~_SYSTEM |0x0002|
|~_HIDDEN |0x0004|
|~_CASE_INSENSITIVE |0x0008|
|~_ARCHIVE |0x0010|
|~_ENCRYPTED |0x0020|
|~_COMPRESSED |0x0040|
|~_SPARSE |0x0080|
|~_APPEND_ONLY |0x0100|
|~_IMMUTABLE |0x0200|
|~_SYNC |0x0400|
|~_TRANSLATION_ERR |0x0800|

# &sect;8.3 Rename flag

(WIP)

SSH_FXF_RENAME_OVERWRITE 0x00000001
SSH_FXF_RENAME_ATOMIC 0x00000002
SSH_FXF_RENAME_NATIVE 0x00000004

# &sect;9.1 Response status code

(WIP)

SSH_FX_OK 0
SSH_FX_EOF 1
SSH_FX_NO_SUCH_FILE 2
SSH_FX_PERMISSION_DENIED 3
SSH_FX_FAILURE 4
SSH_FX_BAD_MESSAGE 5
SSH_FX_NO_CONNECTION 6
SSH_FX_CONNECTION_LOST 7
SSH_FX_OP_UNSUPPORTED 8
SSH_FX_INVALID_HANDLE 9
SSH_FX_NO_SUCH_PATH 10
SSH_FX_FILE_ALREADY_EXISTS 11
SSH_FX_WRITE_PROTECT 12
SSH_FX_NO_MEDIA 13
SSH_FX_NO_SPACE_ON_FILESYSTEM 14
SSH_FX_QUOTA_EXCEEDED 15
SSH_FX_UNKNOWN_PRINCIPAL 16
SSH_FX_LOCK_CONFLICT 17
SSH_FX_DIR_NOT_EMPTY 18
SSH_FX_NOT_A_DIRECTORY 19
SSH_FX_INVALID_FILENAME 20
SSH_FX_LINK_LOOP 21
SSH_FX_CANNOT_DELETE 22
SSH_FX_INVALID_PARAMETER 23
SSH_FX_FILE_IS_A_DIRECTORY 24
SSH_FX_BYTE_RANGE_LOCK_CONFLICT 25
SSH_FX_BYTE_RANGE_LOCK_REFUSED 26
SSH_FX_DELETE_PENDING 27
SSH_FX_FILE_CORRUPT 28
SSH_FX_OWNER_INVALID 29
SSH_FX_GROUP_INVALID 30
SSH_FX_NO_MATCHING_BYTE_RANGE_LOCK 31