Bradley M. Kuhn c1f10c3379 Larger presentation -> CCS report examples

cp -pa presentations/2hr-GPL-compliance-focus/2hr-GPL.md presentations/ccs-report-examples/ccs-examples.md

Plan to reduce this just to the CCS examples.

2018-09-26 09:30:21 -07:00

27 KiB

Raw Blame History

% A Practical Guide to Compliance with the GNU GPL % Bradley M. Kuhn and Karen M. Sandler % Thursday 19 January 2016

Audience

Our goal here is to move faster or slower based on audience knowledge.
There are folks in this audience who have worked with this stuff for years, and those who are completely new.
We want these presentations to be valuable to all of you.

Audience

Please, don't be embarrassed:
- Ever GPL expert in the world, including us, started as a student who knew none of this.
This is a course; raise your hand if you are confused or have a question.
We are glad to go "off-slides" and get your questions answered.

The Tutorial's Textbook

This tutorial actually has a 125-page textbook.
You can download it (PDF or online HTML browse, or the source code!) from copyleft.org/guide
The text is in integration and culmination of every freely licensed material on copyleft (and GPL in particular) we could find.
We don't mind if you read the text while we talk and raise your hand with questions.

How this Tutorial Go?

Materials presented will mix the simple & complex.
We cannot possibly cover the entire GPL and compliance procedures in merely two hours.
- a full course could take a whole day or more.
- but we'll give you the key highlights.

Outline

Discuss: motivations, origins, then a few of GPL's sections.
Turn to focus to how it relates to meeting the requirements of the license (aka compliance).
If you haven't asked enough questions at that point, we'll then still have lots of time at the end to take questions and answer them.

Why Listen To Us?

Conservancy operates and practices license compliance activities extremely transparently.
So you have access to drafters, interpreters, enforcers.
Someday, we may (or already have) sit across the table from you.
Our transparency does make your job easier.

The Mindset of GPL

GPL protects software freedom.
Ultimate goal: make sure every user has the four freedoms.
- Freedom to run the software.
- Freedom to study and modify the software.
- Freedom to share the software.
- Freedom to distribute modified versions.
Every clause in GPL was designed to uphold one of these freedoms.
- Or, it's a compromise of drafting in adoption vs. freedom debate.

Using Copyright

GPL is primarily a copyright license. + Software is copyrighted. + License grants key freedoms. + Requirement prohibit activities that take away freedoms.
General concept: copyleft.
Specific implementation: GPL.

Conditional Permissions

A copyleft license grants copyright permissions, conditionally.
Think of the phrase: “provided that”
“provided that”: appears (in some form) only
- 4 times in GPLv2
- 9 times in GPLv3.

Compare To Proprietary Licenses

Yes, the GPL has its requirements.
But none of these activities are ever permitted under proprietary licenses.
If you don't like what the GPL requires you to do, then just use proprietary software instead.
That way, you know the answer to every “Am I allowed to?” question is “no”
rather than: “yes, but only as long as you …”
Many business advantages to copyleft...

The Technical Gap

Understanding GPL well requires a some software expertise & legal expertise.
You don't have to be a professional on either side to grok it.
- but you're best off if you're a professional in one & an amateur in the other.
Most important technical concepts you need:
- source code, binaries, methods of distribution.

Modification As a Center Provision

GPL's primary copyright hook is copyright controls on the right to modify.
GPL's central tenant:
You can make a modified version of various types privately as much as you'd like.
When you distribute that modified version, you have requirements to meet.
Technological considerations dictate necessity of more complex rules for certain types of modifications.

GPLv2 § 2(a-b)

[GPLv2§]2. You may modify your copy or copies of the Program or any portion of it, thus forming a work based on the Program, and copy and distribute such modifications or work under the terms of Section 1 above, provided that you also meet all of these conditions:

a) You must cause the modified files to carry prominent notices stating that you changed the files and the date of any change.

b) You must cause any work that you distribute or publish, that in whole or in part contains or is derived from the Program or any part thereof, to be licensed as a whole at no charge to all third parties under the terms of this License.

GPLv3§5(a-c)

You may convey a work based on the Program, or the modifications to produce it from the Program, in the form of source code under the terms of section 4, provided that you also meet all of these conditions:

a) The work must carry prominent notices stating that you modified it, and giving a relevant date.

b) The work must carry prominent notices stating that it is released under this License and any conditions added under section 7. This requirement modifies the requirement in section 4 to "keep intact all notices".

c) You must license the entire work, as a whole, under this License to anyone who comes into possession of a copy. This License will therefore apply, along with any applicable section 7 additional terms, to the whole of the work, and all its parts, regardless of how they are packaged. This License gives no permission to license the work in any other way, but it does not invalidate such permission if you have separately received it.

GPLv2§2¶ penultimates

These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it.

Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works based on the Program.

GPLv3 §0 ¶1-5

"Copyright" also means copyright-like laws that apply to other kinds of works, such as semiconductor masks.

"The Program" refers to any copyrightable work licensed under this License. Each licensee is addressed as "you". "Licensees" and "recipients" may be individuals or organizations.

To "modify" a work means to copy from or adapt all or part of the work in a fashion requiring copyright permission, other than the making of an exact copy. The resulting work is called a "modified version" of the earlier work or a work "based on" the earlier work.

A "covered work" means either the unmodified Program or a work based on the Program.

Binaries (Object Code) are Modifications

Software that the computer understands is different than software humans read.
There is often a process required to modify (and/or translate) the software from human-readable + This process can be done ahead of time.
Separation of source and binary was the first way proprietary software companies discovered to subjugate users. + GPL uses the fact that binaries are modifications (which are often distribution) to prevent that subjugation.

GPLv2 § 3(a-b)

[GPLv2§]3. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following:

a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,

b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange;

GPLv3 § 6(a-b)

[GPLv3 § ] 6. Conveying Non-Source Forms.

You may convey a covered work in object code form under the terms of sections 4 and 5, provided that you also convey the machine-readable Corresponding Source under the terms of this License, in one of these ways:

a) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by the Corresponding Source fixed on a durable physical medium customarily used for software interchange.

b) Convey the object code in, or embodied in, a physical product (including a physical distribution medium), accompanied by a written offer, valid for at least three years and valid for as long as you offer spare parts or customer support for that product model, to give anyone who possesses the object code either (1) a copy of the Corresponding Source for all the software in the product that is covered by this License, on a durable physical medium customarily used for software interchange, for a price no more than your reasonable cost of physically performing this conveying of source, or (2) access to copy the Corresponding Source from a network server at no charge.

GPLv3 § 1 ¶ 1, 4-6

The "source code" for a work means the preferred form of the work for making modifications to it. "Object code" means any non-source form of a work.

The "Corresponding Source" for a work in object code form means all the source code needed to generate, install, and (for an executable work) run the object code and to modify the work, including scripts to control those activities. However, it does not include the work's System Libraries, or general-purpose tools or generally available free programs which are used unmodified in performing those activities but which are not part of the work. For example, Corresponding Source includes interface definition files associated with source files for the work, and the source code for shared libraries and dynamically linked subprograms that the work is specifically designed to require, such as by intimate data communication or control flow between those subprograms and other parts of the work.

The Corresponding Source need not include anything that users can regenerate automatically from other parts of the Corresponding Source.

The Corresponding Source for a work in source code form is that same work.

What's a GPL Violation?

GPL (both v2 and v3) require:
- The whole work licensed under GPL.
- (which means all copyrighted material added must be under GPL-compatible licenses.)
- Complete, Corresponding Source (CCS) of that work provided, under GPL.
The licenses terminate upon violation …
- … thus failure to comply means lost distribution rights.
- … enforcement uses this rights termination as leverage to restore compliance.

Enforcement is Technical

Copyleft's policy goals related to technical acts.
- modifying, building, and installing software is a technical process.
In embedded systems, this process is rarely straightforward.
- Yet GPL requires that such be possible.
In enforcement, we talk about “the CCS adequately meeting GPL's requirements”

Compliance-Friendly Development

Use revision control ...
- ... to pull in vendor branch.
- ... to tag releases.
Avoid "Build Guru" ...
- ... by documenting build process.
- ... and versioning it, too.

GPL Binary Requirements

(v2 § 3, v3 § 6)

Four options:
- Source alongside binary (v2/v3).
- Offer for source (v2/v3).
- Internet side-by-side distribution (v3).
- Torrent distribution (v3).

Source Alongside Binary

Simplest option
Obligations end at distribution time.
Physical media required.

Offer For Source

Useful if not shipping CD already.
Lasts three years.
Mail fulfillment required (not in v3).

Side-By-Side Distribution

Not in GPLv2, pedantically speaking.
Always been considered compliant for v2.
v3 clarifies this.

Peer-to-Peer Distribution

v2 obviously couldn't consider this.
v3 allows distribution of equally seeded source and binary.

Preparing Corresponding Source

(v2 § 3, v3 § 1)

Make sure all sources are present.
- revision system helps a lot here.
Build scripts
- make sure someone skilled in art can build it.

Termination

(v2 § 4, v3 § 8)

v2 is automatic and permanent.
v3 has auto-reinstatement.
- 60 day self-correction timeout.
- 30 day penalty-less after notice.
Usually, you need copyright holder to reinstate.

Actual Enforcement

The Principles of Community-Oriented GPL Enforcement at sfconservancy.org/linux-compliance/principles.html.
Send a Letter, carefully finding right person.
Communication is key.
Ask for CCS candidates.

The "Rounds"

Ideally (it's only happened to me twice) the first source release is perfect.
- but we don't live in an ideal world.
The worst I've ever experienced is 22 rounds.
We send detailed reports.

No Build Instructions

The primary issues we found were a dearth of build instructions as well as a complete lack of installation instructions. There was no information that mentioned how one might build each package so we had to guess about which Makefile and/or build script to run for each package. And in many cases it was not possible or straight-forward to build - this must be resolved in the next source candidate.

Making General Recommendations

We generally recommend that the source release be a single file (ie. one tarball containing all packages required for the build) that includes a README or similar in the main directory explaining exactly how to build and install all of the packages. See section 21.2 of http://compliance.guide/pristine-example for an excellent example.

Suspicious, But Not Captious.

Also, we noticed that some packages mentioned in the "OPEN SOURCE SOFTWARE NOTICE" included with the device (and also downloaded as part of the source release; see Open_Source_Software_Notice_and_Privacy_Policy.pdf ) could not be found in the source release. For example, we found "Software: Samba 3.0.XX" in the notice, but could not find any trace of Samba in the source release. Please ensure that all the software included in the notice is included in the source release as well.

Nesting Doll Packages

Once extracted, the 3 .rar files above produce the following output 
files:
     * busybox-1.21.1.rar
     * AB_A0101.123.tar.gz
     * source.rar
     * a small text file that gives two-word descriptions of the above files

Actual(ly Trying to) Build

This file included no instructions for how one might build it so we 
tried to run "make" but received the following error:

$ make
.../busybox-1.21.1/scripts/gcc-version.sh: line 11: 
arm-none-linux-gnueabi-gcc: command not found

Toolchain?

The toolchain is rarely considered mandatory as part of “the scripts”.
Admittedly, it doesn't control compilation, it is compilation.
The script here is explaining precisely what type of toolchain is needed.
Something like: “GCC vX built with the following ./configure line” is usually adequate.
But including the toolchain is a nice step to make it easy for your users.

> the scripts used to **control compilation** and installation of the executable.

— GPLv2§3

We Guess at Compiler Anyway

So we searched for an arm-none-linux-gnueabi- cross-compiler in the other files but could not find one. We then tried to use our own (be editing the PATH appropriately), which did get us past this error. Note that this is not acceptable in a source release - the cross-compiler that a user must use needs to be clearly indicated (name, version, etc.) and/or included with the source release.

Feedback on Small Problems

 Once we had the custom cross-compiler configured, we then ran into these 
 errors:
 
 $ make
 .../busybox-1.21.1/scripts/gen_build_files.sh: Permission denied
 make: *** [gen_build_files] Error 127
 
 $ make
 .../busybox-1.21.1/scripts/mkconfigs: Permission denied
 make: *** [include/config/MARKER] Error 126
 
 $ make
 /bin/sh: applets/usage_compressed: Permission denied
 make[1]: *** [include/usage_compressed.h] Error 126
 make: *** [applets_dir] Error 2
 
 $ make
 .../busybox-1.21.1/scripts/trylink: Permission denied
 make: *** [busybox_unstripped] Error 126
 
 In each case, we found the mentioned file and then added executable 
 permissions to it (ie. "chmod u+x scripts/gen_build_files.sh").  This 
 must be fixed in the next source release - please set the executable 
 bits on the above files appropriately in the archive file you 
 distribute.

Install Instructions missing

After fixing the above, a "busybox" binary was generated. However, there were no instructions to indicate how one might install this binary on the device. Such instructions are required by GPLv2, under which BusyBox is licensed. Please include the instructions in your next source release.

Build "Only Seems" To build

For the AAB_A0101.123.tar.gz package, we ran "./build.sh", the build took about 140 seconds, which is less than one would expect for building all of the programs listed in the "OPEN SOURCE SOFTWARE NOTICE". The only files we could immediately find that were clearly the result of this "./build.sh" invocation were some kernel image binaries, found in path/path/path/path/path/KERNEL_OBJ . This path was not mentioned at all and we had to guess at where they might be.

Maybe Proprietary Kernel Modules?

Furthermore, there were no .ko files generated, which is abnormal for a build of the kernel, Linux. Please ensure that all .ko files which are used on the system are generated with "./build.sh" or a similar script.

Weird versioning

 * The following libraries have different versions in the firmware than
    is built from the candidate CCS.  Specifically, your candidate CCS
    contains version "1800", and the firmware has version "2400".  Since
    most of these libraries are licensed under the LGPL, you are required
    to have the complete, corresponding source present for the correct
    version as distributed in the firmware.  You also must include the
    "scripts to control compilation and installation of the executable".
 
       * lib/libgio-2.0.so.0.2400.2
       * lib/libglib-2.0.so.0.2400.2
       * lib/libgmodule-2.0.so.0.2400.2
       * lib/libgobject-2.0.so.0.2400.2
       * lib/libgthread-2.0.so.0.2400.2
       * lib/libz.so.1.2.5  (version 1.2.2 is provided in the sources)

Weird Build Issues Over Many Candidates

You mentioned in your Round 6 commentary that you have corrected the thatlib issues. However, we are unable to see what you mean. There are now two copies of thatlib, one in 2624.7_524/uclinux-rootfs/lib/thatlib/, as well as the one in yourlibs. We aren't sure which one you intend to be built to generate the binaries on the firmware. When we try to build the yourlibs one from scratch, by cleaning the whole area, we get the following build issues. Here's what we did:

Getting Really build-technical

We ran:

  make -C libsrc/thatlib install

which did not work because of a missing Makefile error. We read the
build source and discovered that the Makefile, etc, for that directory
is generated by running:

   cd libsrc/thatlib/thatlib-0.9.22_mipsel-uclibc; sh configure_thatlib_mipsel-uclibc

Once we did that

   make -C libsrc/thatlib install

 worked correctly. The only remaining binaries were in build source and
 discovered that the Makefile, etc, for that directory is generated by
 running:

   cd libsrc/thatlib/thatlib-0.9.22_mipsel-uclibc; sh configure_thatlib_mipsel-uclibc

Getting Really build-technical

Once we did that

   make -C libsrc/thatlib install

 worked correctly. The only remaining binaries were in
 ./libsrc/thatlib/\{YOURLIB_ROOT_DIR\}/ which looks like a build with a
 misconfigured environment somehow, so we simply removed that
 directory.

 Then, after running make clean, thatlib failed with the following
 errors. Random .o/.so files laying around in the thatlib source
 directory, and then it failing to build correctly after they are
 removed.  If there some set of .so files you claim are not required
 as part of the C&CS since thatlib is LGPL'd, we understand that, but
 the rest of the sources must build and install those other .so's.
 Here's the build error we get in the bdvdlibs version:

Getting Really build-technical

 mkdir .libs/libthatlibwm_default.a.tmp
 (cd .libs/libthatlibwm_default.a.tmp && ar x ../../.libs/libthatlibwm_default.a)
 mkdir .libs/libthatlibwm_default.a.tmp
 (cd .libs/libthatlibwm_default.a.tmp && ar x ../../.libs/libthatlibwm_default.a)
 /opt/toolchains/crosstools_sf-linux-2.6.18.0_gcc-4.2-9ts_uclibc-nptl-0.9.29-20070423_20080702/bin//mipsel-uclibc-
   ld -o libthatlibwm_default.o -r .libs/libthatlibwm_default.a.tmp/*.o
 /opt/toolchains/crosstools_sf-linux-2.6.18.0_gcc-4.2-9ts_uclibc-nptl-0.9.29-20070423_20080702/bin//mipsel-uclibc-
   ld: .libs/libthatlibwm_default.a.tmp/default.o: Relocations in generic ELF (EM: 3)
 /opt/toolchains/crosstools_sf-linux-2.6.18.0_gcc-4.2-9ts_uclibc-nptl-0.9.29-20070423_20080702/bin//mipsel-uclibc-
   ld: .libs/libthatlibwm_default.a.tmp/default.o: Relocations in generic ELF (EM: 3)
 /opt/toolchains/crosstools_sf-linux-2.6.18.0_gcc-4.2-9ts_uclibc-nptl-0.9.29-20070423_20080702/bin//mipsel-uclibc-
   ld: .libs/libthatlibwm_default.a.tmp/default.o: Relocations in generic ELF (EM: 3)
 /opt/toolchains/crosstools_sf-linux-2.6.18.0_gcc-4.2-9ts_uclibc-nptl-0.9.29-20070423_20080702/bin//mipsel-uclibc-
   ld: .libs/libthatlibwm_default.a.tmp/default.o: Relocations in generic ELF (EM: 3)
 .libs/libthatlibwm_default.a.tmp/default.o: could not read symbols: File in wrong format
 make[4]: *** [libthatlibwm_default.o] Error 1

Proprietary Linux Modules Are Everywhere

We did find one .ko file that was already included in the package, but wasn't built when we ran "./build.sh". This is path/path/android_X.X/device/device-type/mydevice.ko , which notes that its license is "GPL v2" in the modinfo, but for which we could find no source code in the source release. Please ensure that the source code for mydevice.ko is included in the next source candidate.

Proprietary Linux Modules Are Everywhere

 * The following files are derivative of the kernel named Linux and
    therefore covered by the GPL.  However, no source code, scripts to
    control compilation nor installation are included in your CCS
    candidate:
          lib/modules/myfilesystem.ko
          lib/modules/mydevicecontroller.ko
          lib/modules/myblockdevice.ko
          lib/modules/mypcicard.ko

Non-Technical GPL Compliance Issues

Regarding over the air updates: we'd like to see a screenshot or other details documenting what has now been implemented by BestBuy to make sure the offer for source appears to users appropriately after upgrade. There was a consensus reached on the last conference call how this would be done, so we only need follow up and implementation on that.

Binary Comparison.

 Note that we did not receive a firmware image to compare this with 
(though we do have the device).  Company's website did not appear to 
have any firmware images available for download.  It would be helpful to 
have such an image for the next CCS check.

The above source candidate was downloaded from 
http:///sourcez.company.com/en/search/index.htm?keywords=X1234Y, which 
was alluded to in Company's 2017-01-18 email to us that said:

"You can check this website 
http://sourcez.company.com/en/search/index.htm "

The email did not mention how to use that website, but we found that by 
entering "X1234Y" into the top right search box that we could find the 
source file list.

Note that the offer for source included in the web UI of the device said 
to email NAME@COMPANY.com , which is how the above instructions for 
downloading the source were received.

More Info / Talk License

URLs / Social Networking / Email:
- Pls. support Conservancy: sfconservancy.org/supporter/
- If you hold copyrights in Linux, Debian, Samba, or BusyBox, you can join our enforcement coalition. Contact us!
- The Guide is available & welcomes contributions at copyleft.org.
- Conservancy: sfconservancy.org & @conservancy.
- Me: faif.us & ebb.org/bkuhn
- Slides: ebb.org/bkuhn/talks.

Presentation and slides are: Copyright © Bradley M. Kuhn (2008–2011, 2015, 2017), Karen M. Sandler (2017), and are licensed under the Creative Commons Attribution-Share Alike 4.0 International License.

27 KiB Raw Blame History Unescape Escape

Audience

Audience

The Tutorial's Textbook

How this Tutorial Go?

Outline

Why Listen To Us?

The Mindset of GPL

Using Copyright

Conditional Permissions

Compare To Proprietary Licenses

The Technical Gap

Modification As a Center Provision

GPLv2 § 2(a-b)

GPLv3§5(a-c)

GPLv2§2¶ penultimates

GPLv3 §0 ¶1-5

Binaries (Object Code) are Modifications

GPLv2 § 3(a-b)

GPLv3 § 6(a-b)

GPLv3 § 1 ¶ 1, 4-6

What's a GPL Violation?

Enforcement is Technical

Compliance-Friendly Development

GPL Binary Requirements

Source Alongside Binary

Offer For Source

Side-By-Side Distribution

Peer-to-Peer Distribution

Preparing Corresponding Source

Termination

Actual Enforcement

The "Rounds"

No Build Instructions

Making General Recommendations

Suspicious, But Not Captious.

Nesting Doll Packages

Actual(ly Trying to) Build

Toolchain?

We Guess at Compiler Anyway

Feedback on Small Problems

Install Instructions missing

Build "Only Seems" To build

Maybe Proprietary Kernel Modules?

Weird versioning

Weird Build Issues Over Many Candidates

Getting Really build-technical

Getting Really build-technical

Getting Really build-technical

Proprietary Linux Modules Are Everywhere

Proprietary Linux Modules Are Everywhere

Non-Technical GPL Compliance Issues

Binary Comparison.

More Info / Talk License

27 KiB

Raw Blame History