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1 ------------------------------------------------------------------------------ 2 Contribution of libburnia-project.org to the GNU Operating System 3 ------------------------------------------------------------------------------ 4 GNU xorriso. By Thomas Schmitt <scdbackup@gmx.net> 5 Derived from and supported by libburnia-project.org, published via: 6 http://www.gnu.org/software/xorriso/xorriso_eng.html 7 http://www.gnu.org/software/xorriso/xorriso-1.5.4.tar.gz 8 Provided under GPL version 3 or later. No warranty. 9 ------------------------------------------------------------------------------ 10 11 12 xorriso is a program which copies file objects from POSIX compliant 13 filesystems into Rock Ridge enhanced ISO 9660 filesystems and allows 14 session-wise manipulation of such filesystems. It can load the management 15 information of existing ISO images and it writes the session results to 16 optical media or to filesystem objects. 17 Vice versa xorriso is able to restore file objects from ISO 9660 filesystems. 18 19 A special property of xorriso is that it needs neither an external ISO 9660 20 formatter program nor an external burn program for CD or DVD but rather 21 incorporates the libraries of libburnia-project.org . 22 23 Currently it is fully supported on GNU/Linux with kernels >= 2.4, 24 on FreeBSD with ATAPI/CAM support enabled in the kernel, see atapicam(4), 25 on OpenSolaris (tested with kernel 5.11), 26 on NetBSD (tested with 6.1.2 and 6.1.3). 27 On other X/Open compliant systems there will only be POSIX i/o with disk 28 file objects, but no direct MMC operation on CD/DVD/BD drives. 29 30 By using this software you agree to the disclaimer at the end of this text: 31 "... without even the implied warranty ..." 32 33 34 Compilation, First Glimpse, Installation 35 36 The most simple way to get xorriso from source code is the GNU xorriso tarball. 37 38 Prerequisites: 39 The tarball contains everything that is needed except the following system 40 components: 41 libc, libpthread 42 plus on Solaris: libvolmgt 43 plus on FreeBSD: libiconv, libcam, IDE and SATA drives need atapicam 44 Optional at compile time are: 45 libreadline and the readline-dev headers, or libedit and its header, 46 make dialog mode more convenient. 47 zlib and zlib-devel allow zisofs compression. 48 on GNU/Linux: libacl and libacl-devel allow getting and setting ACLs. 49 If they were present at compile time, then the optional libraries have to 50 be present at runtime, too. 51 52 Obtain xorriso-1.5.4.tar.gz, take it to a directory of your choice and do: 53 54 tar xzf xorriso-1.5.4.tar.gz 55 cd xorriso-1.5.4 56 57 Within that directory execute: 58 59 ./configure --prefix=/usr 60 make 61 62 This will produce a binary named 63 ./xorriso/xorriso 64 65 If you want xorriso to report a "Build timestamp" with its option -version : 66 make buildstamped 67 68 You may strip the binary to reduce it in size 69 strip ./xorriso/xorriso 70 71 You may copy or move it to a directory where it can be found by the shell, 72 or you may execute xorriso at the place where it was built, 73 or you may execute as superuser: 74 make install 75 76 For general concepts, options and usage examples see 77 info xorriso 78 info xorrisofs 79 info xorrecord 80 or 81 man 1 xorriso 82 man 1 xorrisofs 83 man 1 xorrecord 84 85 You may get a first glimpse by e.g. 86 info ./xorriso/xorriso.info 87 man ./xorriso/xorriso.1 88 89 The installation creates several alias links pointing to the xorriso binary: 90 xorrisofs starts xorriso with -as mkisofs emulation already enabled 91 xorrecord starts xorriso with -as cdrecord emulation already enabled 92 osirrox starts with -osirrox image-to-disk copying already enabled 93 94 95 By default xorriso will depend on libreadline if the library and its 96 development header files are present at compile time. If not, then it will 97 try to depend on libedit and its header file. 98 Both conditional dependencies can be avoided by running 99 ./configure --prefix=/usr --disable-libreadline 100 make clean ; make 101 Never omit the "make clean" command after switching enabling of libreadline. 102 If you want to explicitly allow only the use of libedit, then do 103 ./configure --prefix=/usr --disable-libreadline --enable-libedit 104 105 Other deliberate dependency reduction options of ./configure are: 106 --disable-libacl avoid use of ACL functions like acl_to_text() 107 --disable-xattr avoid use of xattr functions like listxattr() on Linux 108 or extattr_list_file() on FreeBSD 109 --disable-zlib avoid use of zlib functions like compress2() 110 this also avoids the use of libjte and option -jigdo. 111 112 xorriso brings own system adapters which allow burning optical media on 113 GNU/Linux, FreeBSD, Solaris, NetBSD. 114 Alternatively it can use libcdio-0.83 or later for sending commands to 115 optical drives: 116 --enable-libcdio 117 118 xorriso allows to use external processes as file content filters. This is 119 a potential security risk which may be avoided by ./configure option 120 --disable-external-filters 121 122 By default the filter feature is disabled if effective user id and real 123 user id differ. This ban can be lifted by 124 --enable-external-filters-setuid 125 126 Sometimes xorriso will yield better write performance on GNU/Linux if 64 KB are 127 transmitted in each write operation rather than 32 KB. See option -dvd_obs . 128 64k can be made default at configure time by: 129 --enable-dvd-obs-64k 130 131 For xorriso -as cdrecord emulation only: 132 In some situations GNU/Linux may deliver a better write performance to drives 133 if the track input is read with O_DIRECT (see man 2 open). The included libburn 134 and the cdrecord emulation of xorriso can be told to use this peculiar read 135 mode by: 136 --enable-track-src-odirect 137 138 Linux only: 139 libburn tries to avoid a collision with udev's drive examination by waiting 140 0.1 seconds before opening the device file for a longer time, after udev 141 might have been alarmed by drive scanning activities. 142 The waiting time can be set at ./configure time with microsecond granularity. 143 E.g. 2 seconds: 144 CFLAGS="$CFLAGS -DLibburn_udev_wait_useC=2000000" 145 ./configure ...options... 146 Waiting can be disabled by zero waiting time: 147 CFLAGS="$CFLAGS -DLibburn_udev_wait_useC=0" 148 Alternatively, libburn can try to be nice by opening the device file, 149 closing it immediately, waiting, and only then opening it for real: 150 CFLAGS="$CFLAGS -DLibburn_udev_extra_open_cyclE -DLibburn_udev_wait_useC=500000" 151 152 153 xorriso under control of a (GUI) frontend process 154 155 The dialog mode allows frontend programs to connect via pipes to the standard 156 input and output of xorriso. Several commands of xorriso help with receiving 157 and parsing of reply messages. 158 159 As a proof of concept, there is the Tcl/Tk script xorriso-tcltk which can 160 be launched by this shell command: 161 162 xorriso-tcltk 163 164 Or in the xorriso build directory, without installation of xorriso: 165 166 xorriso/xorriso -launch_frontend frontend/xorriso-tcltk --stdio -- 167 168 In the running GUI, click with the rightmost mouse button on any GUI element 169 to get its particular help text. The "Help" button at the upper right corner 170 gives a short introduction and instructions for some common use cases. 171 See also file frontend/README-tcltk. 172 See its Tcl code for getting an idea how this gets achieved. 173 174 The script is part of the tarball and gets installed by make install. If a 175 xorriso distro package does not install it, you may get it directly from 176 https://dev.lovelyhq.com/libburnia/libisoburn/blob/master/frontend/xorriso-tcltk 177 178 Further there is the C program frontend/frontend_pipes_xorriso.c which 179 forks a xorriso process and shows the same communication gestures as 180 xorriso-tcltk. 181 In particular it connects to xorriso via two pipes, sends commands, waits 182 for all replies of a command, picks info out of the xorriso message sieve, 183 and parses reply message lines into words. 184 185 The bash script frontend/sh_on_named_pipes.sh forks a xorriso process 186 connected to two pipes. It then runs a dialog loop, sends commands to xorriso, 187 and displays the replies. 188 189 The sh script frontend/xorriso_broker.sh is intended to execute xorriso 190 commands on a permanently running xorriso process. 191 It gets an id_string by which it looks for named pipes with a running xorriso 192 process. If no such pipe is found, then it starts a xorriso connected to 193 newly created pipes. 194 After this is done, the optionally given xorriso arguments are written into 195 the stdin pipe from where xorriso will read and execute them. The script will 196 end but the xorriso process will go on and wait for more commands. 197 198 199 Drives and Disk File Objects 200 201 The user of libisoburn applications needs rw-permission for the CD/DVD/BD 202 drives which shall be used, even if only reading is intended. 203 A list of rw-accessible drives can be obtained by 204 205 xorriso -devices 206 207 CD devices which offer not enough permission are invisible to normal users. 208 The superuser should be able to see any usable drive and then set the 209 permissions as needed. 210 On Linux, FreeBSD, and NetBSD, rw-permissions are needed. 211 On Solaris, the privilege "sys_devices" and r-permission are needed. 212 213 The output of xorriso -devices might look like 214 215 0 -dev '/dev/sr0' rwrw-- : 'TSSTcorp' 'CDDVDW SH-S203B' 216 1 -dev '/dev/hda' rwrw-- : 'HL-DT-ST' 'DVD-ROM GDR8162B' 217 218 On Linux, full and insecure enabling of both for everybody would look like 219 chmod a+rw /dev/sr0 /dev/hda 220 This is equivalent to the traditional setup chmod a+x,u+s cdrecord. 221 222 On FreeBSD, device permissions are to be set in /etc/devfs.rules. 223 On Solaris, pfexec privileges may be restricted to "basic,sys_devices". 224 On NetBSD, rw-permission may be granted by chmod a+rw /dev/rcd?d. 225 See below "System Dependent Drive Permission Examples". 226 227 I strongly discourage to run xorriso with setuid root or via sudo ! 228 It is not checked for the necessary degree of hacker safety. 229 Better consider to grant the necessary permissions to group "floppy" 230 and to add users to it. 231 232 233 A possible source of problems are hald or other automounters. 234 If you can spot a process "hald-addon-storage" with the address of 235 your desired drive, then consider to kill it. 236 A similar process "udisks-daemon: polling ..." can be seen on newer Linuxes. 237 238 On Debian GNU/Linux 6.0.2 amd64 there is 239 /lib/udev/rules.d/80-udisks.rules 240 where one can remove all CD drives ("sr*") from the list of automountable 241 devices: 242 KERNEL=="sd*|hd*|mmcblk*|mspblk*", ENV{UDISKS_PRESENTATION_NOPOLICY}="0" 243 # KERNEL=="sd*|hd*|sr*|mmcblk*|mspblk*", ENV{UDISKS_PRESENTATION_NOPOLICY}="0" 244 Copying the recognition criterion from 245 /etc/udev/rules.d/70-persistent-cd.rules 246 one can prevent automounting a single drive, too: 247 SUBSYSTEM=="block", ENV{ID_CDROM}=="?*", ENV{ID_PATH}=="pci-0000:00:11.0-scsi-2:0:0:0", ENV{UDISKS_PRESENTATION_NOPOLICY}:="1" 248 249 If you cannot get rid of the automounter, try whether it helps to always load 250 the drive tray manually before starting a write run of xorriso. Wait until the 251 drive light is off and the mounted media appears. 252 Then try to unmount the mounted media before a write run. 253 254 255 Besides true optical drives, xorriso can also address disk files as input or 256 output drives. By default paths to files under /dev are accepted only if the 257 device represents a real optical drive. Other device files may be addressed 258 by prepending "stdio:" to the path. 259 Like: 260 xorriso -dev stdio:/dev/sdb ...more arguments... 261 This rule may be changed by xorriso option -drive_class. 262 Prefix "mmc:" causes a path to be accepted only if it is a real optical drive 263 which is accessible by generic SCSI/MMC commands. 264 265 266 xorriso-dd-target 267 268 GNU xorriso comes with a script named 269 xorriso-dd-target/xorriso-dd-target 270 which uses the util-linux program lsblk to find suitable hard-disk-like 271 target devices for copying hard-disk bootable ISO images onto them. Such images 272 are offered by GNU/Linux distributions for installing their system. 273 274 xorriso-dd-target gets installed only if ./configure detects to run on a 275 GNU/Linux system. It refuses to start on non-Linux kernels or if program lsblk 276 is not found in /usr/sbin, /sbin, /usr/bin, /bin. 277 278 For introduction, examples, and details see in the build directory 279 man xorriso-dd-target/xorriso-dd-target.1 280 info xorriso-dd-target/xorriso-dd-target.info 281 282 283 Testing 284 285 For automated and manual tests of xorriso's functionality see file 286 releng/README 287 288 289 Result comparison with self produced ISO images 290 291 We are quite sure that libisofs produces accurate representations of the disk 292 files. This opinion is founded on a lot of test burns and checks by a little 293 test program which compares files from the mounted image with the orignals 294 on disk. It uses the normal POSIX filesystem calls, i.e. no libburnia stuff. 295 296 This program is not installed systemwide but stays in the installation 297 directory of the xorriso tarball as test/compare_file . Usually it is 298 run as -exec payload of a find command. It demands at least three arguments: 299 The path of the first file to compare, the prefix1 to be cut off from path 300 and the prefix2 which gets prepended afterwards to obtain the path of the 301 second file to compare. 302 As further argument there can be -no_ctime which suppresses the comparison 303 of ctime date stamps. 304 The exit value is 0 if no difference was detected, non-0 else. 305 306 Example: After 307 xorriso ... -pathspecs on -add /=/original/dir -- -commit_eject all 308 mount /media/dvd 309 cd test 310 compare tree /media/dvd with tree /original/dir : 311 find /original/dir -exec ./compare_file '{}' /original/dir /media/dvd ';' \ 312 | less 313 and vice versa: 314 find /media/dvd -exec ./compare_file '{}' /media/dvd /original/dir ';' \ 315 | less 316 317 318 File Formats 319 320 Sector Maps 321 322 Sector maps describe the valid and invalid blocks on a media or a disk copy of 323 a media. xorriso creates and reads these file with its option -check_media. 324 325 The file begins with 32 bytes of cleartext of which the last one is a 326 newline character. The first 25 say "xorriso sector bitmap v2 ", the 327 remaining six characters give the size of the info text as decimal number. 328 This number of bytes follows the first 32 and will not be interpreted 329 by xorriso. They are rather to inform a human reader about the media type 330 and its track layout. 331 After the info text there are two 4 byte signed integers, most significant 332 byte first. The first one, N, gives the number of bits in the following bitmap 333 and the second number S gives the number of 2 KiB blocks governed by a single 334 bit in the map. Then come the bits in form of 8-bit bytes. 335 Data block M is covered by bit B=M/S in the map, bit number B is stored in 336 byte B/8 as bit B%8. A valid readable data block has its bit set to 1. 337 338 Checksum Tags 339 340 Checksum tags are data blocks inside an ISO 9660 image which do not belong to 341 any file but rather tell the MD5 of a certain range of data blocks. 342 343 The superblock checksum tag is written after the ECMA-119 volume descriptors. 344 The tree checksum tag is written after the ECMA-119 directory entries. 345 The session checksum tag is written after all payload including the checksum 346 array. (Then follows padding.) 347 348 The tags are single lines of printable text, padded by 0 bytes. They have 349 the following format: 350 351 Tag_id pos=# range_start=# range_size=# [session_start|next=#] md5=# self=#\n 352 353 Parameters md5= and self= are 32 digit hex, the others are decimal numbers. 354 355 Tag_id distinguishes the following tag types 356 "libisofs_rlsb32_checksum_tag_v1" Relocated 64 kB superblock tag 357 "libisofs_sb_checksum_tag_v1" Superblock tag 358 "libisofs_tree_checksum_tag_v1" Directory tree tag 359 "libisofs_checksum_tag_v1" Session end tag 360 361 A relocated superblock may appear at LBA 0 of an image which was produced for 362 being stored in a disk file or on overwritable media (e.g. DVD+RW, BD-RE). 363 xorriso records the first session at LBA 32. A follow-up session 364 begins at the next block address which is divisible by 32 and higher than the 365 address of the previous session's end tag. Normally no session starts after the 366 address given by relocated superblock parameter session_start=. 367 Session oriented media like CD-R[W], DVD-R, DVD+R, BD-R will have no relocated 368 superblock but rather bear a table-of-content on media level. 369 370 A tag is valid if pos= tells its own block address and self= tells its own MD5 371 up to the last hex digit of md5=. range_start= tells the first block that is 372 covered by md5=, range_size= tells the number of blocks covered by md5=. 373 Relocated superblocks tell the block address of their session by session_start=. 374 Superblock and tree tag tell the block address of the next tag by next=. 375 The newline character at the end is mandatory. 376 377 378 libisoburn 379 380 xorriso is based on libisofs which does ISO 9660 filesystem aspects and on 381 libburn which does the input and output aspects. Parts of this foundation 382 are accessed via libisoburn, which is closely related to xorriso. 383 384 libisoburn provides several services: 385 - Encapsulation of coordination between libisofs and libburn. 386 - Emulation of ISO 9660 multi-session on overwritable media 387 or random access files. 388 - Implementation of the xorriso API. 389 390 The sourcecode of all three libraries is included in the GNU xorriso tarball. 391 It is compiled with xorriso and linked statically. 392 But you may as well get and install releases of libburn and libisofs, in order 393 to be able to install a release of libisoburn which produces libisoburn.so.1 394 and a matching dynamically linked xorriso binary. 395 This binary is very lean but depends on properly installed libraries of 396 suitable revision. 397 398 Dynamic library and compile time header requirements for libisoburn-1.5.4 : 399 - libburn.so.4 , version libburn-1.5.4 or higher 400 - libisofs.so.6 , version libisofs-1.5.4 or higher 401 libisoburn and xorriso will not start with libraries which are older than their 402 headers seen at compile time. So compile in the oldest possible installation 403 setup unless you have reason to enforce a newer bug fix level. 404 405 GNU xorriso has less runtime dependencies and can be moved more freely. 406 407 408 System Dependent Drive Permission Examples 409 410 Accessing the optical drives requires privileges which usually are granted 411 only to the superuser. GNU/Linux, FreeBSD, Solaris, and NetBSD offer quite 412 different approaches for avoiding the need for unrestricted privileges. 413 414 First check whether some friendly system setting already allows you to 415 access the drives as normal user: 416 xorriso -devices 417 Those drives of which you see address and type strings are already usable. 418 419 If there remain drives invisible which the superuser can see by the same 420 command, then the following examples might help: 421 422 --------------- 423 On all systems: 424 --------------- 425 Add the authorized users of CD drives to group "floppy" in /etc/group. 426 If missing: create this group. 427 Changes to /etc/group often only affect new login sessions. So log out and in 428 before making the first tests. 429 430 ------------- 431 On GNU/Linux: 432 ------------- 433 Allow rw-access to the drives 434 chgrp floppy /dev/sr0 /dev/sr1 435 chmod g+rw /dev/sr0 /dev/sr1 436 It might be necessary to perform chgrp and chmod after each reboot or to 437 edit distro dependent device configuration files for permanent settings. 438 439 ----------- 440 On FreeBSD: 441 ----------- 442 Edit /etc/devfs.rules and make sure to have these lines 443 [localrules=10] 444 add path 'acd*' mode 0664 group floppy 445 add path 'cd*' mode 0664 group floppy 446 add path 'pass*' mode 0664 group floppy 447 add path 'xpt*' mode 0664 group floppy 448 [localrules=5] 449 add path 'pass*' mode 0664 group floppy 450 add path 'cd*' mode 0664 group floppy 451 add path 'xpt*' mode 0664 group floppy 452 add path 'acd*' mode 0664 group floppy 453 454 Edit /etc/rc.conf and add the following line if missing 455 devfs_system_ruleset="localrules" 456 457 This gets into effect by reboot or by command 458 /etc/rc.d/devfs start 459 460 ----------- 461 On Solaris: 462 ----------- 463 Run xorriso by 464 pfexec xorriso ...arguments... 465 466 The following settings will make pfexec keep original UID and EUID and prevent 467 most superuser powers. Be aware that you still can manipulate all device files 468 if you have the file permissions for that. 469 Full root privileges for xorriso can then be acquired only by command su. 470 471 Edit /etc/security/exec_attr and add this line to the other "Media Backup" 472 lines: 473 Media Backup:solaris:cmd:::/usr/local/bin/xorriso:privs=basic,sys_devices 474 Edit /etc/user_attr and add profile "Media Backup" to the user's line: 475 thomas::::profiles=Media Backup,Primary Administrator;roles=root 476 See also man privileges, man exec_attr, man user_attr. 477 478 Then allow the group r-access to the drives 479 pfexec chgrp floppy /dev/rdsk/c3t0d0s2 /dev/rdsk/c4t0d0s2 480 pfexec chmod g+r /dev/rdsk/c3t0d0s2 /dev/rdsk/c4t0d0s2 481 The last two commands have to be executed after each boot. I do not know 482 the relevant device configuration files yet. 483 484 ---------- 485 On NetBSD: 486 ---------- 487 Allow rw-access to the drives 488 chgrp floppy /dev/rcd[01]d 489 chmod g+rw /dev/rcd[01]d 490 491 ------------------------------------------------------------------------------ 492 493 This program is free software; you can redistribute it and/or modify 494 it under the terms of the GNU General Public License version 3 or later 495 as published by the Free Software Foundation. 496 497 This program is distributed in the hope that it will be useful, 498 but WITHOUT ANY WARRANTY; without even the implied warranty of 499 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 500 GNU General Public License for more details. 501 502 You should have received a copy of the GNU General Public License 503 along with this program; if not, write to the Free Software 504 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 505 506 ------------------------------------------------------------------------------ 507 508 GNU xorriso is feature-wise equivalent to the dynamic compilation of 509 libburnia libraries and libburnia program xorriso. 510 It restricts itself to a technical form where the legal commitments of the 511 libburnia project and the legal intentions of FSF match completely. 512 513 Libburnia project is committed to provide support for this copy in the same 514 way as for its own software releases. It is further committed to keep its 515 own licenses open for obtaining future copies under GPLv2+. 516 517 ------------------------------------------------------------------------------ 518 libburnia program xorriso is based on and sub project of: 519 libburnia-project.org 520 By Mario Danic <mario.danic@gmail.com>, libburn, libisofs 521 Vreixo Formoso <metalpain2002@yahoo.es>, libisofs, libisoburn 522 Thomas Schmitt <scdbackup@gmx.net>, libburn, libisofs, 523 libisoburn, xorriso 524 Copyright (C) 2006-2021 Mario Danic, Vreixo Formoso, Thomas Schmitt. 525 526 libburnia-project.org is inspired by and in libburn still containing parts 527 of old 528 Libburn. By Derek Foreman <derek@signalmarketing.com> and 529 Ben Jansens <xor@orodu.net> 530 Copyright (C) 2002-2006 Derek Foreman and Ben Jansens 531 532 GNU xorriso contains libjte out of source package jigit >= 1.17 533 Copyright (C) 2000-2007 Free Software Foundation, Inc. 534 2004-2011 Steve McIntyre 535 2010-2011 George Danchev, Thomas Schmitt 536 537 GNU xorriso contains xorriso-dd-target 538 Copyright (C) 2019-2021 Nio Wiklund alias sudodus, Thomas Schmitt 539 540 ------------------------------------------------------------------------------ 541 542 This text itself is 543 Copyright (c) 2007 - 2021 Thomas Schmitt <scdbackup@gmx.net> 544 and is freely distributable. 545 It shall only be modified in sync with the technical properties of xorriso. 546 If you make use of the license to derive modified versions of xorriso 547 then you are entitled to modify this text under that same license. 548