------------------------------------------------------------------------------ Contribution of libburnia-project.org to the GNU Operating System ------------------------------------------------------------------------------ GNU xorriso. By Thomas Schmitt Derived from and supported by libburnia-project.org, published via: http://www.gnu.org/software/xorriso/xorriso_eng.html http://www.gnu.org/software/xorriso/xorriso-1.5.6.pl02.tar.gz Provided under GPL version 3 or later. No warranty. ------------------------------------------------------------------------------ xorriso is a program which copies file objects from POSIX compliant filesystems into Rock Ridge enhanced ISO 9660 filesystems and allows session-wise manipulation of such filesystems. It can load the management information of existing ISO images and it writes the session results to optical media or to filesystem objects. Vice versa xorriso is able to restore file objects from ISO 9660 filesystems. A special property of xorriso is that it needs neither an external ISO 9660 formatter program nor an external burn program for CD or DVD but rather incorporates the libraries of libburnia-project.org . Currently it is fully supported on GNU/Linux with kernels >= 2.4, on FreeBSD with ATAPI/CAM support enabled in the kernel, see atapicam(4), on OpenSolaris (tested with kernel 5.11), on NetBSD (tested with 6.1.2 and 6.1.3). On other X/Open compliant systems there will only be POSIX i/o with disk file objects, but no direct MMC operation on CD/DVD/BD drives. By using this software you agree to the disclaimer at the end of this text: "... without even the implied warranty ..." Compilation, First Glimpse, Installation The most simple way to get xorriso from source code is the GNU xorriso tarball. Prerequisites: The tarball contains everything that is needed except the following system components: libc, libpthread plus on Solaris: libvolmgt plus on FreeBSD: libiconv, libcam, IDE and SATA drives need atapicam Optional at compile time are: libreadline and the readline-dev headers, or libedit and its header, make dialog mode more convenient. zlib and zlib-devel allow zisofs compression. on GNU/Linux: libacl and libacl-devel allow getting and setting ACLs. If they were present at compile time, then the optional libraries have to be present at runtime, too. Obtain xorriso-1.5.6.pl02.tar.gz, take it to a directory of your choice and do: tar xzf xorriso-1.5.6.pl02.tar.gz cd xorriso-1.5.6 Within that directory execute: ./configure --prefix=/usr make This will produce a binary named ./xorriso/xorriso If you want xorriso to report a "Build timestamp" with its option -version : make buildstamped You may strip the binary to reduce it in size strip ./xorriso/xorriso You may copy or move it to a directory where it can be found by the shell, or you may execute xorriso at the place where it was built, or you may execute as superuser: make install For general concepts, options and usage examples see info xorriso info xorrisofs info xorrecord or man 1 xorriso man 1 xorrisofs man 1 xorrecord You may get a first glimpse by e.g. info ./xorriso/xorriso.info man ./xorriso/xorriso.1 The installation creates several alias links pointing to the xorriso binary: xorrisofs starts xorriso with -as mkisofs emulation already enabled xorrecord starts xorriso with -as cdrecord emulation already enabled osirrox starts with -osirrox image-to-disk copying already enabled By default xorriso will depend on libreadline if the library and its development header files are present at compile time. If not, then it will try to depend on libedit and its header file. Both conditional dependencies can be avoided by running ./configure --prefix=/usr --disable-libreadline make clean ; make Never omit the "make clean" command after switching enabling of libreadline. If you want to explicitly allow only the use of libedit, then do ./configure --prefix=/usr --disable-libreadline --enable-libedit Other deliberate dependency reduction options of ./configure are: --disable-libacl avoid use of ACL functions like acl_to_text() --disable-xattr avoid use of xattr functions like listxattr() on Linux or extattr_list_file() on FreeBSD --disable-zlib avoid use of zlib functions like compress2() this also avoids the use of libjte and option -jigdo. xorriso brings own system adapters which allow burning optical media on GNU/Linux, FreeBSD, Solaris, NetBSD. Alternatively it can use libcdio-0.83 or later for sending commands to optical drives: --enable-libcdio xorriso allows to use external processes as file content filters. This is a potential security risk which may be avoided by ./configure option --disable-external-filters By default the filter feature is disabled if effective user id and real user id differ. This ban can be lifted by --enable-external-filters-setuid Sometimes xorriso will yield better write performance on GNU/Linux if 64 KB are transmitted in each write operation rather than 32 KB. See option -dvd_obs . 64k can be made default at configure time by: --enable-dvd-obs-64k For xorriso -as cdrecord emulation only: In some situations GNU/Linux may deliver a better write performance to drives if the track input is read with O_DIRECT (see man 2 open). The included libburn and the cdrecord emulation of xorriso can be told to use this peculiar read mode by: --enable-track-src-odirect Linux only: libburn tries to avoid a collision with udev's drive examination by waiting 0.1 seconds before opening the device file for a longer time, after udev might have been alarmed by drive scanning activities. The waiting time can be set at ./configure time with microsecond granularity. E.g. 2 seconds: CFLAGS="$CFLAGS -DLibburn_udev_wait_useC=2000000" ./configure ...options... Waiting can be disabled by zero waiting time: CFLAGS="$CFLAGS -DLibburn_udev_wait_useC=0" Alternatively, libburn can try to be nice by opening the device file, closing it immediately, waiting, and only then opening it for real: CFLAGS="$CFLAGS -DLibburn_udev_extra_open_cyclE -DLibburn_udev_wait_useC=500000" xorriso under control of a (GUI) frontend process The dialog mode allows frontend programs to connect via pipes to the standard input and output of xorriso. Several commands of xorriso help with receiving and parsing of reply messages. As a proof of concept, there is the Tcl/Tk script xorriso-tcltk which can be launched by this shell command: xorriso-tcltk Or in the xorriso build directory, without installation of xorriso: xorriso/xorriso -launch_frontend frontend/xorriso-tcltk --stdio -- In the running GUI, click with the rightmost mouse button on any GUI element to get its particular help text. The "Help" button at the upper right corner gives a short introduction and instructions for some common use cases. See also file frontend/README-tcltk. See its Tcl code for getting an idea how this gets achieved. The script is part of the tarball and gets installed by make install. If a xorriso distro package does not install it, you may get it directly from https://dev.lovelyhq.com/libburnia/libisoburn/blob/master/frontend/xorriso-tcltk Further there is the C program frontend/frontend_pipes_xorriso.c which forks a xorriso process and shows the same communication gestures as xorriso-tcltk. In particular it connects to xorriso via two pipes, sends commands, waits for all replies of a command, picks info out of the xorriso message sieve, and parses reply message lines into words. The bash script frontend/sh_on_named_pipes.sh forks a xorriso process connected to two pipes. It then runs a dialog loop, sends commands to xorriso, and displays the replies. The sh script frontend/xorriso_broker.sh is intended to execute xorriso commands on a permanently running xorriso process. It gets an id_string by which it looks for named pipes with a running xorriso process. If no such pipe is found, then it starts a xorriso connected to newly created pipes. After this is done, the optionally given xorriso arguments are written into the stdin pipe from where xorriso will read and execute them. The script will end but the xorriso process will go on and wait for more commands. Drives and Disk File Objects The user of libisoburn applications needs rw-permission for the CD/DVD/BD drives which shall be used, even if only reading is intended. A list of rw-accessible drives can be obtained by xorriso -devices CD devices which offer not enough permission are invisible to normal users. The superuser should be able to see any usable drive and then set the permissions as needed. On Linux, FreeBSD, and NetBSD, rw-permissions are needed. On Solaris, the privilege "sys_devices" and r-permission are needed. The output of xorriso -devices might look like 0 -dev '/dev/sr0' rwrw-- : 'TSSTcorp' 'CDDVDW SH-S203B' 1 -dev '/dev/hda' rwrw-- : 'HL-DT-ST' 'DVD-ROM GDR8162B' On Linux, full and insecure enabling of both for everybody would look like chmod a+rw /dev/sr0 /dev/hda This is equivalent to the traditional setup chmod a+x,u+s cdrecord. On FreeBSD, device permissions are to be set in /etc/devfs.rules. On Solaris, pfexec privileges may be restricted to "basic,sys_devices". On NetBSD, rw-permission may be granted by chmod a+rw /dev/rcd?d. See below "System Dependent Drive Permission Examples". I strongly discourage to run xorriso with setuid root or via sudo ! It is not checked for the necessary degree of hacker safety. Better consider to grant the necessary permissions to group "floppy" and to add users to it. A possible source of problems are hald or other automounters. If you can spot a process "hald-addon-storage" with the address of your desired drive, then consider to kill it. A similar process "udisks-daemon: polling ..." can be seen on newer Linuxes. On Debian GNU/Linux 6.0.2 amd64 there is /lib/udev/rules.d/80-udisks.rules where one can remove all CD drives ("sr*") from the list of automountable devices: KERNEL=="sd*|hd*|mmcblk*|mspblk*", ENV{UDISKS_PRESENTATION_NOPOLICY}="0" # KERNEL=="sd*|hd*|sr*|mmcblk*|mspblk*", ENV{UDISKS_PRESENTATION_NOPOLICY}="0" Copying the recognition criterion from /etc/udev/rules.d/70-persistent-cd.rules one can prevent automounting a single drive, too: SUBSYSTEM=="block", ENV{ID_CDROM}=="?*", ENV{ID_PATH}=="pci-0000:00:11.0-scsi-2:0:0:0", ENV{UDISKS_PRESENTATION_NOPOLICY}:="1" If you cannot get rid of the automounter, try whether it helps to always load the drive tray manually before starting a write run of xorriso. Wait until the drive light is off and the mounted media appears. Then try to unmount the mounted media before a write run. Besides true optical drives, xorriso can also address disk files as input or output drives. By default paths to files under /dev are accepted only if the device represents a real optical drive. Other device files may be addressed by prepending "stdio:" to the path. Like: xorriso -dev stdio:/dev/sdb ...more arguments... This rule may be changed by xorriso option -drive_class. Prefix "mmc:" causes a path to be accepted only if it is a real optical drive which is accessible by generic SCSI/MMC commands. xorriso-dd-target GNU xorriso comes with a script named xorriso-dd-target/xorriso-dd-target which uses the util-linux program lsblk to find suitable hard-disk-like target devices for copying hard-disk bootable ISO images onto them. Such images are offered by GNU/Linux distributions for installing their system. xorriso-dd-target gets installed only if ./configure detects to run on a GNU/Linux system. It refuses to start on non-Linux kernels or if program lsblk is not found in /usr/sbin, /sbin, /usr/bin, /bin. For introduction, examples, and details see in the build directory man xorriso-dd-target/xorriso-dd-target.1 info xorriso-dd-target/xorriso-dd-target.info Testing For automated and manual tests of xorriso's functionality see file releng/README Result comparison with self produced ISO images We are quite sure that libisofs produces accurate representations of the disk files. This opinion is founded on a lot of test burns and checks by a little test program which compares files from the mounted image with the orignals on disk. It uses the normal POSIX filesystem calls, i.e. no libburnia stuff. This program is not installed systemwide but stays in the installation directory of the xorriso tarball as test/compare_file . Usually it is run as -exec payload of a find command. It demands at least three arguments: The path of the first file to compare, the prefix1 to be cut off from path and the prefix2 which gets prepended afterwards to obtain the path of the second file to compare. As further argument there can be -no_ctime which suppresses the comparison of ctime date stamps. The exit value is 0 if no difference was detected, non-0 else. Example: After xorriso ... -pathspecs on -add /=/original/dir -- -commit_eject all mount /media/dvd cd test compare tree /media/dvd with tree /original/dir : find /original/dir -exec ./compare_file '{}' /original/dir /media/dvd ';' \ | less and vice versa: find /media/dvd -exec ./compare_file '{}' /media/dvd /original/dir ';' \ | less File Formats Sector Maps Sector maps describe the valid and invalid blocks on a media or a disk copy of a media. xorriso creates and reads these file with its option -check_media. The file begins with 32 bytes of cleartext of which the last one is a newline character. The first 25 say "xorriso sector bitmap v2 ", the remaining six characters give the size of the info text as decimal number. This number of bytes follows the first 32 and will not be interpreted by xorriso. They are rather to inform a human reader about the media type and its track layout. After the info text there are two 4 byte signed integers, most significant byte first. The first one, N, gives the number of bits in the following bitmap and the second number S gives the number of 2 KiB blocks governed by a single bit in the map. Then come the bits in form of 8-bit bytes. Data block M is covered by bit B=M/S in the map, bit number B is stored in byte B/8 as bit B%8. A valid readable data block has its bit set to 1. Checksum Tags Checksum tags are data blocks inside an ISO 9660 image which do not belong to any file but rather tell the MD5 of a certain range of data blocks. The superblock checksum tag is written after the ECMA-119 volume descriptors. The tree checksum tag is written after the ECMA-119 directory entries. The session checksum tag is written after all payload including the checksum array. (Then follows padding.) The tags are single lines of printable text, padded by 0 bytes. They have the following format: Tag_id pos=# range_start=# range_size=# [session_start|next=#] md5=# self=#\n Parameters md5= and self= are 32 digit hex, the others are decimal numbers. Tag_id distinguishes the following tag types "libisofs_rlsb32_checksum_tag_v1" Relocated 64 kB superblock tag "libisofs_sb_checksum_tag_v1" Superblock tag "libisofs_tree_checksum_tag_v1" Directory tree tag "libisofs_checksum_tag_v1" Session end tag A relocated superblock may appear at LBA 0 of an image which was produced for being stored in a disk file or on overwritable media (e.g. DVD+RW, BD-RE). xorriso records the first session at LBA 32. A follow-up session begins at the next block address which is divisible by 32 and higher than the address of the previous session's end tag. Normally no session starts after the address given by relocated superblock parameter session_start=. Session oriented media like CD-R[W], DVD-R, DVD+R, BD-R will have no relocated superblock but rather bear a table-of-content on media level. A tag is valid if pos= tells its own block address and self= tells its own MD5 up to the last hex digit of md5=. range_start= tells the first block that is covered by md5=, range_size= tells the number of blocks covered by md5=. Relocated superblocks tell the block address of their session by session_start=. Superblock and tree tag tell the block address of the next tag by next=. The newline character at the end is mandatory. libisoburn xorriso is based on libisofs which does ISO 9660 filesystem aspects and on libburn which does the input and output aspects. Parts of this foundation are accessed via libisoburn, which is closely related to xorriso. libisoburn provides several services: - Encapsulation of coordination between libisofs and libburn. - Emulation of ISO 9660 multi-session on overwritable media or random access files. - Implementation of the xorriso API. The sourcecode of all three libraries is included in the GNU xorriso tarball. It is compiled with xorriso and linked statically. But you may as well get and install releases of libburn and libisofs, in order to be able to install a release of libisoburn which produces libisoburn.so.1 and a matching dynamically linked xorriso binary. This binary is very lean but depends on properly installed libraries of suitable revision. Dynamic library and compile time header requirements for libisoburn-1.5.4 : - libburn.so.4 , version libburn-1.5.4 or higher - libisofs.so.6 , version libisofs-1.5.4 or higher libisoburn and xorriso will not start with libraries which are older than their headers seen at compile time. So compile in the oldest possible installation setup unless you have reason to enforce a newer bug fix level. GNU xorriso has less runtime dependencies and can be moved more freely. System Dependent Drive Permission Examples Accessing the optical drives requires privileges which usually are granted only to the superuser. GNU/Linux, FreeBSD, Solaris, and NetBSD offer quite different approaches for avoiding the need for unrestricted privileges. First check whether some friendly system setting already allows you to access the drives as normal user: xorriso -devices Those drives of which you see address and type strings are already usable. If there remain drives invisible which the superuser can see by the same command, then the following examples might help: --------------- On all systems: --------------- Add the authorized users of CD drives to group "floppy" in /etc/group. If missing: create this group. Changes to /etc/group often only affect new login sessions. So log out and in before making the first tests. ------------- On GNU/Linux: ------------- Allow rw-access to the drives chgrp floppy /dev/sr0 /dev/sr1 chmod g+rw /dev/sr0 /dev/sr1 It might be necessary to perform chgrp and chmod after each reboot or to edit distro dependent device configuration files for permanent settings. ----------- On FreeBSD: ----------- Edit /etc/devfs.rules and make sure to have these lines [localrules=10] add path 'acd*' mode 0664 group floppy add path 'cd*' mode 0664 group floppy add path 'pass*' mode 0664 group floppy add path 'xpt*' mode 0664 group floppy [localrules=5] add path 'pass*' mode 0664 group floppy add path 'cd*' mode 0664 group floppy add path 'xpt*' mode 0664 group floppy add path 'acd*' mode 0664 group floppy Edit /etc/rc.conf and add the following line if missing devfs_system_ruleset="localrules" This gets into effect by reboot or by command /etc/rc.d/devfs start ----------- On Solaris: ----------- Run xorriso by pfexec xorriso ...arguments... The following settings will make pfexec keep original UID and EUID and prevent most superuser powers. Be aware that you still can manipulate all device files if you have the file permissions for that. Full root privileges for xorriso can then be acquired only by command su. Edit /etc/security/exec_attr and add this line to the other "Media Backup" lines: Media Backup:solaris:cmd:::/usr/local/bin/xorriso:privs=basic,sys_devices Edit /etc/user_attr and add profile "Media Backup" to the user's line: thomas::::profiles=Media Backup,Primary Administrator;roles=root See also man privileges, man exec_attr, man user_attr. Then allow the group r-access to the drives pfexec chgrp floppy /dev/rdsk/c3t0d0s2 /dev/rdsk/c4t0d0s2 pfexec chmod g+r /dev/rdsk/c3t0d0s2 /dev/rdsk/c4t0d0s2 The last two commands have to be executed after each boot. I do not know the relevant device configuration files yet. ---------- On NetBSD: ---------- Allow rw-access to the drives chgrp floppy /dev/rcd[01]d chmod g+rw /dev/rcd[01]d ------------------------------------------------------------------------------ This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 3 or later as published by the Free Software Foundation. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA ------------------------------------------------------------------------------ GNU xorriso is feature-wise equivalent to the dynamic compilation of libburnia libraries and libburnia program xorriso. It restricts itself to a technical form where the legal commitments of the libburnia project and the legal intentions of FSF match completely. Libburnia project is committed to provide support for this copy in the same way as for its own software releases. It is further committed to keep its own licenses open for obtaining future copies under GPLv2+. ------------------------------------------------------------------------------ libburnia program xorriso is based on and sub project of: libburnia-project.org By Mario Danic , libburn, libisofs Vreixo Formoso , libisofs, libisoburn Thomas Schmitt , libburn, libisofs, libisoburn, xorriso Copyright (C) 2006-2023 Mario Danic, Vreixo Formoso, Thomas Schmitt. libburnia-project.org is inspired by and in libburn still containing parts of old Libburn. By Derek Foreman and Ben Jansens Copyright (C) 2002-2006 Derek Foreman and Ben Jansens GNU xorriso contains libjte out of source package jigit >= 1.17 Copyright (C) 2000-2007 Free Software Foundation, Inc. 2004-2011 Steve McIntyre 2010-2011 George Danchev, Thomas Schmitt GNU xorriso contains xorriso-dd-target Copyright (C) 2019-2021 Nio Wiklund alias sudodus, Thomas Schmitt ------------------------------------------------------------------------------ This text itself is Copyright (c) 2007 - 2023 Thomas Schmitt and is freely distributable. It shall only be modified in sync with the technical properties of xorriso. If you make use of the license to derive modified versions of xorriso then you are entitled to modify this text under that same license.