Manpage of ppddsetup
Section: User Commands (1)
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ppddsetup - setup, release or get details of a ppdd device
Used to control or display the connection between a ppdd device
and a file or a disc partion.
The program ppddsetup is used to control the connection between a logical
ppdd device and a real file or disc partition. The file or disc partition
must have been initialised previously using ppddinit or ppdncrypt.
The connection is normally established by a simple command.
ppddsetup -s ppdd_device file|disc_partition
e.g. ppddsetup -s /dev/ppdd0 /dev/hda1
e.g. ppddsetup -s /dev/ppdd0 /home/allan/cryptfile
The program will ask for a pass phrase.
This may be either the master or working pass phrase.
On succesful completion of the command the ppdd device can be used to access
the decrypted data just as if it were a disc.
There are other ways of connecting which all involve storing the pass phrase
on disc. There are major security concerns about doing this. It makes sense
only when the file containing the pass phrase is itself on a ppdd device.
The usual scenario is that the root filesystem is encrytpted with ppdd and
the pass phrases for the other filesystems are stored on the encrypted root.
It is then necessary to enter just one pass phrase during the boot phase in
order to access the root filesystem - the rest runs automatically. Do NOT
use the following unless you know what you are doing.
Use the information in /etc/ppddtab to setup everything defined in that file.
ppddsetup -t device | file
The device or file must be defined in /etc/ppddtab. The information which
is not on the command line is taken from the entry in /etc/ppddtab - including
the pass phrase.
ppddsetup -p device | file passphrase-file
Instead of using /etc/ppddtab this form of ppddinit use "passphrase-file"
To display the details about a ppdd device:
e.g. ppddsetup /dev/ppdd0
It is only possible to disconnect the ppdd device from the underlying host
data file or device (disc partition) when there are no more users active
on the device - i.e. no open inodes. If you have mounted the
ppdd device you will need to umount it before the disconnect will work.
ppddsetup -d ppdd_device
e.g. ppddsetup -d /dev/ppdd0
The -c switch can be used in combination with the -d -p and -s switches.
In combination with -s or -p it checks the checksum. If no checksum is available
or if the checksum is wrong the user is asked if he wants to accept this.
In combination with -d it generates a checksum, but only if the device was
also setup with checksums enabled.
As checksum generation or checking involves reading all the data on the device
it can take a long time. Progress messages are output during the process.
If any invalid combination of switches and arguments is used the program
displays a primitive help message. The program takes not more than one
switch and the argument(s) required depends on the switch.
With a ppdd device as agrument and no switches ppddsetup displays the details
of an existing connection between the device and a file or disc partition.
-s setup the connection
Takes the ppdd device and the real device or file as agruments.
The real device must be a block device and would normally be a disc partition
or a floppy disc. The file can reside on any type of filesystem. If it is on
a read-only filesystem the ppdd device must later be mounted read-only.
The file must already exist and must not be a sparse file.
The host partition or file must have been initialised by ppddinit or ppdncrypt.
A valid user entered pass phrase (master or working) is necessary before
ppddsetup will enable the ppdd device.
-d release the connection
This requires the ppdd device as its single argument. The function will
fail if there are any open inodes on the device. The most common failure is
that the ppdd device is still mounted.
-p setup using a passphrase file
Very dangerous - use with care (or just for testing).
-t setup using /etc/ppddtab
-a setup all devices defined in /etc/ppddtab
Slightly less dangerous - see ppddtab(7) for details.
The program returns 0 if everything worked as expected. That means that the
ppdd device has been successfully connected to the host device or file.
The program returns 1 if anything has gone wrong.
All ppdd utilities display fairly meaningful errors (mostly on stderr).
In all cases the errors have a unique error number to help locate the
problem in the source code. If an error message is not clear then best
source of explanation at this stage is the source itself.
The program does not use any environment variables.
Files (and devices) are specified as arguments.
(c) 1999 Allan Latham - version 0.9
- Displaying details
- RETURN VALUE
- SEE ALSO
This document was created by
using the manual pages.
Time: 16:36:54 GMT, September 14, 1999