Consider having a nc binary in the path with a space in its name,
for example '/tmp/fo o/nc'
This results in libvirt running SSH with the following arg value
"'if ''/tmp/fo o/nc'' -q 2>&1 | grep \"requires
an argument\" >/dev/null 2>&1; then ARG=-q0;
else ARG=;fi;''/tmp/fo o/nc'' $ARG -U
/var/run/libvirt/libvirt-sock'"
The use of the single quote escaping was introduced by
commit 6ac6238de3
Author: Guido Günther <agx@sigxcpu.org>
Date: Thu Oct 13 21:49:01 2011 +0200
Use virBufferEscapeShell in virNetSocketNewConnectSSH
to escape the netcat command since it's passed to the shell. Adjust
expected test case output accordingly.
While the intention of this change was good, the result is broken as it
is still underquoted.
On the SSH server side, SSH itself runs the command via the shell.
Our command is then invoking the shell again. Thus we see
$ virsh -c qemu+ssh://root@domokun/system?netcat=%2Ftmp%2Ffo%20o%2Fnc list
error: failed to connect to the hypervisor
error: End of file while reading data: sh: /tmp/fo: No such file or directory: Input/output error
With the second level of escaping added we can now successfully use a nc
binary with a space in the path.
The original test case added was misleading as it illustrated using a
binary path of 'nc -4' which is not a path, it is a command with a
separate argument, which is getting interpreted as a path.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser General
Public License, version 2.1 (or later). Some parts of the code that are
not part of the C library may have the more restrictive GNU General
Public License, version 2.0 (or later). See the files COPYING.LESSER
and COPYING for full license terms & conditions.
Installation
Libvirt uses the GNU Autotools build system, so in general can be built and installed with the usual commands. For example, to build in a manner that is suitable for installing as root, use:
$ ./configure --prefix=/usr --sysconfdir=/etc --localstatedir=/var
$ make
$ sudo make install
While to build & install as an unprivileged user
$ ./configure --prefix=$HOME/usr
$ make
$ make install
The libvirt code relies on a large number of 3rd party libraries. These will
be detected during execution of the configure script and a summary printed
which lists any missing (optional) dependencies.
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- libvirt-users@redhat.com (for user discussions)
- libvir-list@redhat.com (for development only)
Further details on contacting the project are available on the website: