diff options
Diffstat (limited to 'mount/losetup.8')
| -rw-r--r-- | mount/losetup.8 | 84 |
1 files changed, 31 insertions, 53 deletions
diff --git a/mount/losetup.8 b/mount/losetup.8 index 9a42d70a0..d364f4f1e 100644 --- a/mount/losetup.8 +++ b/mount/losetup.8 @@ -1,18 +1,15 @@ -.TH LOSETUP 8 "2003-07-01" "Linux" "MAINTENANCE COMMANDS" +.TH LOSETUP 8 "Nov 24 1993" "Linux" "MAINTENANCE COMMANDS" .SH NAME losetup \- set up and control loop devices .SH SYNOPSIS .ad l .B losetup [ -.RB [ \-e | \-E ] +.B \-e .I encryption ] [ .B \-o .I offset -] [ -.B \-p -.I pfd ] .I loop_device file .br @@ -28,41 +25,27 @@ is used to associate loop devices with regular files or block devices, to detach loop devices and to query the status of a loop device. If only the \fIloop_device\fP argument is given, the status of the corresponding loop device is shown. - -.SS "Encryption" -It is possible to specify transfer functions (for encryption/decryption -or other purposes) using one of the -.B \-E -and -.B \-e -options. -There are two mechanisms to specify the desired encryption: by number -and by name. If an encryption is specified by number then one -has to make sure that the Linux kernel knows about the encryption with that -number, probably by patching the kernel. Standard numbers that are -always present are 0 (no encryption) and 1 (XOR encryption). -When the cryptoloop module is loaded (or compiled in), it uses number 18. -This cryptoloop module wil take the name of an arbitrary encryption type -and finds the module that knows how to perform that encryption. -(Thus, either one uses a number different from 18 with the -.B \-E -option, or one uses a name with the -.B \-e -option.) .SH OPTIONS .IP \fB\-d\fP -Detach the file or device associated with the specified loop device. -.IP "\fB\-E \fIencryption_type\fP" -Enable data encryption with specified number. -.IP "\fB\-e \fIencryption_name\fP" -Enable data encryption with specified name. +detach the file or device associated with the specified loop device. +.IP "\fB\-e \fIencryption\fP" +.RS +enable data encryption. The following keywords are recognized: +.IP \fBNONE\fP +use no encryption (default). +.PD 0 +.IP \fBXOR\fP +use a simple XOR encryption. +.IP \fBDES\fP +use DES encryption. DES encryption is only available if the optional +DES package has been added to the kernel. DES encryption uses an additional +start value that is used to protect passwords against dictionary +attacks. +.PD +.RE .IP "\fB\-o \fIoffset\fP" -The data start is moved \fIoffset\fP bytes into the specified file or +the data start is moved \fIoffset\fP bytes into the specified file or device. -.IP "\fB\-p \fInum\fP" -Read the passphrase from file descriptor with number -.I num -instead of from the terminal. .SH RETURN VALUE .B losetup returns 0 on success, nonzero on failure. When @@ -74,7 +57,7 @@ from determining the status of the device. .SH FILES .nf -/dev/loop0, /dev/loop1, ... loop devices (major=7) +/dev/loop0,/dev/loop1,... loop devices (major=7) .fi .SH EXAMPLE If you are using the loadable module you must have the module loaded @@ -82,23 +65,18 @@ first with the command .IP # insmod loop.o .LP -Maybe also encryption modules are needed. -.IP -# insmod des.o -# insmod cryptoloop.o -.LP The following commands can be used as an example of using the loop device. .nf .IP -# dd if=/dev/zero of=/file bs=1k count=100 -# losetup -e des /dev/loop0 /file +dd if=/dev/zero of=/file bs=1k count=100 +losetup -e des /dev/loop0 /file Password: Init (up to 16 hex digits): -# mkfs -t ext2 /dev/loop0 100 -# mount -t ext2 /dev/loop0 /mnt +mkfs -t ext2 /dev/loop0 100 +mount -t ext2 /dev/loop0 /mnt ... -# umount /dev/loop0 -# losetup -d /dev/loop0 +umount /dev/loop0 +losetup -d /dev/loop0 .fi .LP If you are using the loadable module you may remove the module with @@ -109,8 +87,8 @@ the command .fi .SH RESTRICTION DES encryption is painfully slow. On the other hand, XOR is terribly weak. -.\" .SH AUTHORS -.\" .nf -.\" Original version: Theodore Ts'o <tytso@athena.mit.edu> -.\" Original DES by: Eric Young <eay@psych.psy.uq.oz.au> -.\" .fi +.SH AUTHORS +.nf +Original version: Theodore Ts'o <tytso@athena.mit.edu> +Original DES by: Eric Young <eay@psych.psy.uq.oz.au> +.fi |