similar to: [nbdkit PATCH v3] vddk: Drive library loading from libdir parameter.

From: "Richard W.M. Jones" <rjones@redhat.com> Do not use LD_LIBRARY_PATH to locate the VDDK library. Setting this always causes problems because VDDK comes bundled with broken replacements for system libraries, such as libcrypto.so and libstdc++.so. Two problems this causes which we have seen in the real world: (1) User does ‘export LD_LIBRARY_PATH=vmware-vix-disklib-distrib’

From: "Richard W.M. Jones" <rjones@redhat.com> Do not use LD_LIBRARY_PATH to locate the VDDK library. Setting this always causes problems because VDDK comes bundled with broken replacements for system libraries, such as libcrypto.so and libstdc++.so. Two problems this causes which we have seen in the real world: (1) User does ‘export LD_LIBRARY_PATH=vmware-vix-disklib-distrib’

Do not use LD_LIBRARY_PATH to locate the VDDK library. Setting this always causes problems because VDDK comes bundled with broken replacements for system libraries, such as libcrypto.so and libstdc++.so. Two problems this causes which we have seen in the real world: (1) User does ‘export LD_LIBRARY_PATH=vmware-vix-disklib-distrib’ and that breaks lots of ordinary utilities on their system. (2)

On 2/17/20 12:17 PM, Richard W.M. Jones wrote: > Unfortunately this series doesn't work with the real VDDK library :-( > > I see: > > nbdkit: debug: vddk: config_complete > nbdkit: debug: dlopen shim prefix set to /home/rjones/tmp/vddk-6.7.3/vmware-vix-disklib-distrib/lib64 > > Then a little bit later during VDDK initialization it fails with: > >

On 2/13/20 8:01 AM, Richard W.M. Jones wrote: > Do not use LD_LIBRARY_PATH to locate the VDDK library. Setting this > always causes problems because VDDK comes bundled with broken > replacements for system libraries, such as libcrypto.so and > libstdc++.so. Two problems this causes which we have seen in the real > world: > > (1) User does ‘export

At least the VDDK plugin needs a way to load .so files with a custom directory prepended. Asking the user to set LD_LIBRARY_PATH is too strong (that would leak into the child process created by --run, and makes the user think about issues that we'd rather cover automatically). But overriding dlopen() to make it easier to prepend a directory name under our control requires either a separate

I've got a situation where I need to hook a dlopen() made by VDDK, a proprietary library, where it passes a relative name expecting to resolve to a copy of several libraries, including libstdc++.so, that it installs alongside itself, and fails to load if that resolves to the system libstdc++.so. The simplest solution of providing LD_LIBRARY_PATH is enough to load VDDK, but then poisons

I'm a lot happier with this version: no mucking with dlmopen(). It does add a bit more coupling between nbdkit proper and the vddk plugin (namely, nbdkit now exports a new function that the vddk plugin relies on), but patch 2 adds testsuite coverage of the new function so we shouldn't regress. Patch 1 and 2 are new, patch 3 is unchanged from when Rich posted it in v2, and patch 4 is

Unfortunately this series doesn't work with the real VDDK library :-( I see: nbdkit: debug: vddk: config_complete nbdkit: debug: dlopen shim prefix set to /home/rjones/tmp/vddk-6.7.3/vmware-vix-disklib-distrib/lib64 Then a little bit later during VDDK initialization it fails with: nbdkit: debug: VixDiskLib: Could not load default plugins from

Differences from v4: Patch 1 is simplified: I realized that since we already use -rdynamic for nbdkit (after all, we WANT our dlopen()d plugins to be able to call our nbdkit_* exports), it is only a matter of adding dlopen to the set of symbols that we export. With that done, there is no separate shared library needed; our dlopen shim is now part of nbdkit proper, and we don't have to tweak

We were previously dlopen-ing it in the load() method. This is very early and in particular means that the only possible way to configure where we find the library is through environment variables and not through config parameters. Also it's not necessary as we don't call any functions from the library (such as VixDiskLib_InitEx) until config_complete. This change is neutral refactoring

On Fri, Feb 21, 2020 at 05:02:12PM +0100, Florian Weimer wrote: > * Richard W. M. Jones: > > > On Fri, Feb 21, 2020 at 04:00:30PM +0100, Florian Weimer wrote: > >> * Richard W. M. Jones: > >> > >> > On Fri, Feb 21, 2020 at 01:19:34PM +0100, Florian Weimer wrote: > >> >> I think what confuses me is that keep talking about a single binary,

On 2/14/20 1:02 PM, Eric Blake wrote: > Writing my own dlopen() wrapper directly in nbdkit seems like a > non-starter (my override has to come from a shared library before it can > replace the shared version that would be imported from -ldl, at least > for all subsequent shared library loads that want to bind to the > override). Maybe I spoke too soon. I've tried another

On Mon, Feb 17, 2020 at 09:34:12PM -0600, Eric Blake wrote: > In the next patch, we want to get rid of the requirement for the user > to supply LD_LIBRARY_PATH pointing to vddk libs, if we can derive it > ourselves from libdir. However, VDDK itself requires LD_LIBRARY_PATH > to be set (because it tries to load libraries that in turn depend on a > bare library name, which no manner

I couldn't get this to work in the end. This is the latest non-working version. This email documents what doesn't work for the permanent record. The central problem is that VDDK InitEx() appears to dlopen() various of its own plugins. Although I wasn't able to capture exactly what dlopen() command it is running, the plugins cannot be loaded because they rely on the recompiled

On 2/14/20 3:29 PM, Eric Blake wrote: > On 2/14/20 1:02 PM, Eric Blake wrote: > >> Writing my own dlopen() wrapper directly in nbdkit seems like a >> non-starter (my override has to come from a shared library before it >> can replace the shared version that would be imported from -ldl, at >> least for all subsequent shared library loads that want to bind to the

Previously the presence of the ‘--vddk <libdir>’ option magically enabled VDDK mode. However we want to introduce other transports for VMware conversions so this wasn't a very clean choice. With this commit you must use ‘-it vddk’ to specify that you want VDDK as a disk transport. The previous ‘--vddk <libdir>’ option has been renamed to ‘--vddk-libdir <libdir>’ to be

In the next patch, we want to get rid of the requirement for the user to supply LD_LIBRARY_PATH pointing to vddk libs, if we can derive it ourselves from libdir. However, VDDK itself requires LD_LIBRARY_PATH to be set (because it tries to load libraries that in turn depend on a bare library name, which no manner of dlopen() hacking can work around, and implementing la_objsearch() is no better for

On Tue, Feb 18, 2020 at 11:05:11AM -0600, Eric Blake wrote: > static const char *sonames[] = { > - /* Prefer the newest library in case multiple exist. */ > + /* Prefer the newest library in case multiple exist. Check two > + * possible directories: the usual VDDK installation puts .so > + * files in an arch-specific subdirectory of $libdir (although > + *

--- configure.ac | 5 +++++ plugins/vddk/vddk.c | 4 ++++ 2 files changed, 9 insertions(+) diff --git a/configure.ac b/configure.ac index d71f06e4..57626a76 100644 --- a/configure.ac +++ b/configure.ac @@ -321,6 +321,11 @@ AC_SEARCH_LIBS([dlsym], [dl dld], [ ]) LIBS="$old_LIBS" +old_LIBS="$LIBS" +LIBS="$LIBS -ldl" +AC_CHECK_FUNCS([dlmopen])