From 18ad81db689f92b749fe41da157e43f95ee39cf8 2015-03-12 14:59:22 From: Bradley M. Kuhn Date: 2015-03-12 14:59:22 Subject: [PATCH] VMware Lawsuit FAQ: technical description example Written by Denver Gingerich and me, this description gives one example of how VMware incorporated Linux code with vmkernel and distributed the resulting work. --- diff --git a/www/conservancy/static/linux-compliance/vmware-lawsuit-faq.html b/www/conservancy/static/linux-compliance/vmware-lawsuit-faq.html index 9f219197a1da03cce8fdcd663767e376de96ced9..43127449e0e239f2ec1c3fabbab9fdc8ca0bfced 100644 --- a/www/conservancy/static/linux-compliance/vmware-lawsuit-faq.html +++ b/www/conservancy/static/linux-compliance/vmware-lawsuit-faq.html @@ -131,6 +131,276 @@ (German).

+
Can you explain further in words (rather than a picture) about the central + component in ESXi that the lawsuit alleges violates the GPL?
+
+

The GPL violation at issue involves VMware's ESXi product. + Conservancy independently reviewed ESXi 5.5 and its incomplete + CCS + release as part of our GPL enforcement efforts described above.

+ +

Conservancy's preliminary investigation indicated that the operating + system kernel of VMware ESXi product consists of three key components: +

    +
  • the proprietary component “vmkernel”, which is + released in binary form only,
    • +
  • the kernel module “vmklinux”, which contains modified Linux +Code, and for which (at least some) source code for which is provided. +
  • other kernel modules with device drivers, most of which are + modified Linux drivers, and for which (at least some) source code + is provided.
    • +
+ +

Conservancy examined the incomplete CCS alongside the + binary “vmkernel” component. Such examination indicates that function + in “vmkernel” do make function calls to Linux's kernel code + in the usual way for a single program written in C.

+

+ +
Doesn't VMware's “shim layer” insulate them from GPL + obligations and allow them to keep certain code in their kernel + proprietary?
+ +

Many in the media have talked about the possibility that VMware might + use some so-called “shim layer” between Linux code and + VMware's proprietary code. While, for decades, there has been much talk of + various mechanisms of GPL obligation avoidance, Conservancy believes that + merely modifying technical details of a combination's construction + does not typically influence the legal analysis in a combined or + derivative work scenario.

+ +

Furthermore, the technical details of VMware's alleged GPL violation + do not even mirror the typical scenarios that have usually been called + “shim layers”. Conservancy's analysis of VMware's ESXi + product, in fact, indicates that VMware rather flagrantly combined Linux + code in their own kernel, and evidence seems to indicate the work as a + whole was developed by modifying Linux code in tandem with + modifications to “vmkernel” in a tightly coupled manner.

+ +
Can you give a specific example, with code, showing how + VMware combined Linux source code with their binary-only components?
+ +

There are numerous examples available that show this. The + details of alleged infringement specifically relating to Hellwig's + contributions to Linux are of course the main matter of the + allegations in the litigation, and Conservancy + released the diagram above to exemplify that + issue. Conservancy continues to hope VMware will + agree to make public all court documents as a matter of public + good, since the court documents discuss the specifics of alleged + infringement on Hellwig's copyrights.

+ +

However, Conservancy examined VMware's ESXi 5.5 product in detail + even before Hellwig's enforcement action began. Below is one example + among many where VMware's CCS was incomplete per GPLv2§2(c) and + GPLv2§3(a). (One can verify these results by + downloading and installing the binary and source + packages for VMware's ESXi 5.5 Update 2.) Note that this + example below is not necessarily regarding + Hellwig's copyrights; VMware incorporated Linux code copyrighted by + many others as well into their kernel.

+ +

Example of “vmkernel”'s combination with Linux code

+

As one example, examine the file + called vmkdrivers/src_92/vmklinux_92/vmware/linux_pci.c, + which can be found in the “Open Source” release for + ESXi 5.5.0 Update 2 (5.5U2). A small excerpt from that file, found in the + function LinuxPCIDeviceRemoved(), reads as follows: +

+if (unlikely(
+  /* NOTE: vmk_PCIGetDeviceName is defined in vmvisor64-vmkernel */
+  vmk_PCIGetDeviceName(vmkDev, vmkDevName, sizeof(vmkDevName)-1) != VMK_OK))
+{
+    vmkDevName[0] = 0;
+}
+[...]
+/* VMKAPI_MODULE_CALL_VOID is a macro calling driver's remove() here */
+VMKAPI_MODULE_CALL_VOID(pciDevExt->moduleID,
+                        linuxDev->driver->remove,
+                        linuxDev);
+
+

+

The function, vmk_PCIGetDeviceName() must be defined, with an + implementation, for this code above to work, or even compile. + Inside BLD/build/HEADERS/vmkapi-current-all-public/vmkernel64/release/device/vmkapi_pci_incompat.h, + found in the vmkdrivers package of ESXi 5.5U2, shows a + function header definition for vmk_PCIGetDeviceName(). + However, the source of its implementation is not provided there or + anywhere in the source release.

+ +

Further evidence that the implementation of this function occurs elsewhere + can by found by running objdump -x on the un-vmtar'ed + vmklinux_9 module. Note the following output in the “SYMBOL + TABLE” section: + +

+0000000000000000         *UND*  0000000000000000 vmk_PCIGetDeviceName
+
+ +…and the following lines found in the “RELOCATION RECORDS FOR +[.text]” section: + +
+00000000000327ff R_X86_64_PC32     vmk_PCIGetDeviceName+0xfffffffffffffffc
+0000000000035318 R_X86_64_PC32     vmk_PCIGetDeviceName+0xfffffffffffffffc
+00000000000387e1 R_X86_64_PC32     vmk_PCIGetDeviceName+0xfffffffffffffffc
+000000000003cf40 R_X86_64_PC32     vmk_PCIGetDeviceName+0xfffffffffffffffc
+
+

+ +

The above two properties both suggest that the vmklinux_9 + module requires: (a) a definition of the vmk_PCIGetDeviceName() + function to operate, but (b) that function is not defined + inside vmklinux_9 itself.

+ +

The definition can however be found in binary-only software provided in + ESXi 5.5U2 — specifically, inside a file named k.b00, + which is located in partition 5 on a disk where ESXi has been installed (or + in the ESXi 5.5U2 installer ISO image). Running file + after gunzip on this file yields “ELF 64-bit LSB shared + object”. Meanwhile, file k.b00 reports “gzip + compressed data, was ‘vmvisor64-vmkernel.stripped’”. + These findings strongly suggests this is an image of the + “vmkernel” component. An objdump -x yields this + “SYMBOL TABLE” section: +

+000041800036a408 g     F .text  0000000000000137 vmk_PCIGetDeviceName
+
+ +… which indicated these binary file contains the function body +for vmk_PCIGetDeviceName.

+ +

Finally, after detailed searching, Conservancy found no evidence that any + other code (other than modified Linux code) makes calls + to vmk_PCIGetDeviceName. This provides a strong indication + that this function's primary purpose is to combine Linux code with + “vmkernel”. Conservancy also found other functions where similar analysis + yields similar results as above.

+ +

Given this evidence and related contextual clues, the only logical + conclusions are: +

  • vmklinux_9, as a binary object, dynamically links + with k.b00, another binary object, to form a single running + binary.
    • +
  • That binary contains code licensed under the GPLv2, and can be + distributed in binary form only under permissions provided under + GPLv2 — in particular GPLv2§2 and GPLv2§3.
    • +
  • GPLv2§3(a–b) requires that complete corresponding + machine-readable source code must accompany binary + distributions such as these. GPLv2§3 further states + that for an executable work, complete source code means all the + source code for all modules it contains.
    • +
  • The binary work in question contains modules from k.b00 and + vmlinux_9.
    • +
  • VMware did not provide source code for any modules found in + k.b00.
    • +
  • Therefore, VMware failed to comply with the GPLv2, as such + compliance requires source code (or an offer therefor) for the material + in k.b00.
    • +
+

+

The above is but one piece of evidence among many, but hopefully it helps + to explain the types of “combined work” violations found in + VMware's ESXi product.

+ +
How can I verify Conservancy's technical findings above?
+ +

The binary and source packages mentioned above are available +on VMware's website. These packages contain the +previously-mentioned linux_pci.c, +vmkapi_pci_incompat.h, and k.b00 files, as well as + vmklinux_9 and the source code that builds the latter.

+ +

To obtain the source components, follow these steps (no login is required): + +

    +
  1. Visit https://my.vmware.com/web/vmware/details?downloadGroup=ESXI55U2_OSS&productId=353.
    2. + +
  2. Click the “Download” button beside the text that reads +“Open Source Code for VMware vSphere ESXi 5.5 Update 2”.
    3. + +
  3. Confirm that the SHA-1 hash matches the published one + (d121634668a137ec808b63679fd941cef9a59715), found under “Read + More” on that web page.
    4. + +
  4. Mount (or otherwise open) the + downloaded VMware-ESX-550U2-ODP.iso.
    5. + +
  5. Extract vmkdrivers/src_92/vmklinux_92/vmware/linux_pci.c + and BLD/build/HEADERS/vmkapi-current-all-public/vmkernel64/release/device/vmkapi_pci_incompat.h + from vmkdrivers-gpl/vmkdrivers-gpl.tgz with tar and gzip.
    6. + +
  6. Generate vmklinux_9 by following the steps + in vmkdrivers-gpl/BUILD.txt in the ISO. + (Note: vmklinux_9 is also available pre-built on a running + ESXi system; see below for instructions on how to access it).
    7. + +
  7. You may need the “Supporting Toolchain packages for VMware + vSphere ESXi 5.5.0 Update 2” file from the above download page to + complete the build — upon downloading you will find it is named + VMware-TOOLCHAIN-550u2-ODP.iso and has a SHA-1 hash of + f679e81ffb2f92729917bbc64c2d541cf75b5b94.
    8. + +
+

+ +

To obtain the binary components, follow these steps (a login is required): + +

    +
  1. Register for an account at https://my.vmware.com/web/vmware/registration.
    2. + +
  2. Click the “Activate Now” link in the follow-up email. Enter + the password used at registration time. Click “Continue”.
    3. + +
  3. Visit https://my.vmware.com/web/vmware/evalcenter?p=free-esxi5.
    4. + +
  4. Click “Register” (under the text that reads “You have + not registered for this product”).
    5. + +
  5. Enter the number of servers you plan to install on (e.g., 1). Click + “Continue”.
    6. + +
  6. If the “VMware vSphere Hypervisor 5.5 Update 2 – + Binaries” section is not expanded, click the plus sign next to it.
    7. + +
  7. Click the “Manually Download” link that's beside “ESXi + 5.5 Update 2 ISO image (Includes VMware Tools)”.
    8. + +
  8. Confirm that the SHA-1 hash matches the published one (9475938b51cafc86c8b17d09f2493cb6b4fae927).
    9. + +
  9. Mount (or open via some other means) the +downloaded VMware-VMvisor-Installer-5.5.0.update02-2068190.x86_64.iso.
    10. + +
  10. Find the k.b00 file in the root directory. Extract it +using zcat k.b00 > vmvisor64-vmkernel (or a similar command). +Repeat the steps described above using objdump -x +vmvisor64-vmkernel.
    11. + +
  11. To retrieve vmklinux_9 you will need to install +ESXi on your system by booting the ISO and following the instructions. Once +booted, you can then enable SSH access using “Customize System/View Logs -> +Troubleshooting Options -> Enable SSH”. Login to the system with SSH +and then run find /vmfs -name misc_dri.v00 -print. On the +resulting file, run zcat misc_dri.v00 > misc_dri.vmtar then +vmtar -x misc_dri.vmtar -o misc_dri.tar. You can then extract +misc_dri.tar using the usual tar to extract +usr/lib/vmware/vmkmod/vmklinux_9. The misc_dri.v00 +file is also available next to k.b00 in the root directory of +the ISO (mentioned above), but the vmtar command itself is only +available when logged into an ESXi system. vmtar can be found +at bin/vmtar inside +sb.v00 on the ISO, but one needs vmtar to open +sb.v00, similar to misc_dri.v00 above.
    12. + +
+

+ +

Note that VMware may present you with EULAs and ToS when you download + software from VMware's website. Conservancy strongly suggests that you review these + terms in great detail with the assistance of your own legal counsel before + downloading the software and/or engaging in the process that Conservancy + discusses above.

+
Have others issued statements of support about this action?
Various individuals and groups have publicly stated their support for Conservancy's and Hellwig's actions in this matter. They include: