0a867cd895
iptables and ip6tables have had a "-w" commandline option to grab a systemwide lock that prevents two iptables invocations from modifying the iptables chains since 2013 (upstream commit 93587a04 in iptables-1.4.20). Similarly, ebtables has had a "--concurrent" commandline option for the same purpose since 2011 (in the upstream ebtables commit f9b4bcb93, which was present in ebtables-2.0.10.4). Libvirt added code to conditionally use the commandline option for iptables/ip6tables in upstream commit ba95426d6f (libvirt-1.2.0, November 2013), and for ebtables in upstream commit dc33e6e4a5 (libvirt-1.2.11, November 2014) (the latter actually *re*-added the locking for iptables/ip6tables, as it had accidentally been removed during a refactor of firewall code in the interim). I say "conditionally" because a check was made during firewall module initialization that tried executing a test command with the -w/--concurrent option, and only continued using it for actual commands if that test command completed successfully. At the time the code was added this was a reasonable thing to do, as it had been less than a year since introduction of -w to iptables, so many distros supported by libvirt were still using iptables (and possibly even ebtables) versions too old to have the new commandline options. It is now 2020, and as far as I can discern from repology.org (and manually examining a RHEL7.9 system), every version of every distro that is supported by libvirt now uses new enough versions of both iptables and ebtables that they all have support for -w/--concurrent. That means we can finally remove the conditional code and simply always use them. Signed-off-by: Laine Stump <laine@redhat.com> Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.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
Instructions on building and installing libvirt can be found on the website:
https://libvirt.org/compiling.html
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: