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Laine Stump 6612d1adb7 network: fix problems with SRV records
A patch submitted by Steven Malin last week pointed out a problem with
libvirt's DNS SRV record configuration:

  https://www.redhat.com/archives/libvir-list/2014-March/msg00536.html

When searching for that message later, I found another series that had
been posted by Guannan Ren back in 2012 that somehow slipped between
the cracks:

  https://www.redhat.com/archives/libvir-list/2012-July/msg00236.html

That patch was very much out of date, but also pointed out some real
problems.

This patch fixes all the noted problems by refactoring
virNetworkDNSSrvDefParseXML() and networkDnsmasqConfContents(), then
verifies those fixes by added several new records to the test case.

Problems fixed:

* both service and protocol now have an underscore ("_") prepended on
  the commandline, as required by RFC2782.

  <srv service='sip' protocol='udp' domain='example.com'
       target='tests.example.com' port='5060' priority='10'
       weight='150'/>

  before: srv-host=sip.udp.example.com,tests.example.com,5060,10,150
  after:  srv-host=_sip._udp.example.com,tests.example.com,5060,10,150

* if "domain" wasn't specified in the <srv> element, the extra
  trailing "." will no longer be added to the dnsmasq commandline.

  <srv service='sip' protocol='udp' target='tests.example.com'
       port='5060' priority='10' weight='150'/>

  before: srv-host=sip.udp.,tests.example.com,5060,10,150
  after:  srv-host=_sip._udp,tests.example.com,5060,10,150

* when optional attributes aren't specified, the separating comma is
  also now not placed on the dnsmasq commandline. If optional
  attributes in the middle of the line are not specified, they are
  replaced with a default value in the commandline (1 for port, 0 for
  priority and weight).

  <srv service='sip' protocol='udp' target='tests.example.com'
       port='5060'/>

  before: srv-host=sip.udp.,tests.example.com,5060,,
  after:  srv-host=_sip._udp,tests.example.com,5060

  (actually the would have generated an error, because "optional"
  attributes weren't really optional.)

* The allowed characters for both service and protocol are now limited
  to alphanumerics, plus a few special characters that are found in
  existing names in /etc/services and /etc/protocols. (One exception
  is that both of these files contain names with an embedded ".", but
  "."  can't be used in these fields of an SRV record because it is
  used as a field separator and there is no method to escape a "."
  into a field.) (Previously only the strings "tcp" and "udp" were
  allowed for protocol, but this restriction has been removed, since
  RFC2782 specifically says that it isn't limited to those, and that
  anyway it is case insensitive.)

* the "domain" attribute is no longer required in order to recognize
  the port, priority, and weight attributes during parsing. Only
  "target" is required for this.

* if "target" isn't specified, port, priority, and weight are not
  allowed (since they are meaningless - an empty target means "this
  service is *not available* for this domain").

* port, priority, and weight are now truly optional, as the comments
  originally suggested, but which was not actually true.
2014-03-26 16:42:43 +02:00
.gnulib@ce457d622d maint: update to latest gnulib 2014-03-24 16:29:52 -06:00
build-aux Require spaces around equality comparisons 2014-03-18 11:29:44 +01:00
daemon Indent top-level labels by one space in daemon/ 2014-03-25 14:58:38 +01:00
docs qemu: export disk snapshot support in capabilities 2014-03-26 13:41:25 +01:00
examples Indent top-level labels by one space in examples/ 2014-03-25 14:58:38 +01:00
gnulib maint: update to latest gnulib 2014-01-01 06:02:47 -07:00
include add new virDomainCoreDumpWithFormat API 2014-03-24 14:14:11 -06:00
m4 build: use --with-systemd-daemon as configure option 2014-02-26 05:59:22 -07:00
po Move functions using iscsiadm to viriscsi.c 2014-03-20 18:04:50 +01:00
src network: fix problems with SRV records 2014-03-26 16:42:43 +02:00
tests network: fix problems with SRV records 2014-03-26 16:42:43 +02:00
tools Indent top-level labels by one space in tools/ 2014-03-25 14:58:41 +01:00
.ctags maint: Make ctags work out of the box 2013-07-18 08:47:21 +02:00
.dir-locals.el build: avoid tabs that failed syntax-check 2012-09-06 09:43:46 -06:00
.gitignore tests: cleanup object-locking test 2014-03-18 10:20:49 +01:00
.gitmodules make .gnulib a submodule 2009-07-08 16:17:51 +02:00
.mailmap Autogenerate AUTHORS 2012-10-19 12:44:56 -04:00
AUTHORS.in Add Roman Bogorodskiy to the committers list 2014-02-20 20:51:08 +04:00
COPYING maint: follow recommended practice for using LGPL 2013-05-20 14:15:21 -06:00
COPYING.LESSER maint: follow recommended practice for using LGPL 2013-05-20 14:15:21 -06:00
ChangeLog-old maint: typo fixes 2013-10-22 16:49:32 +01:00
HACKING Add a rule for indenting labels 2014-03-25 14:58:41 +01:00
Makefile.am Introduce Libvirt Wireshark dissector 2014-01-20 17:09:41 +01:00
Makefile.nonreentrant maint: use LGPL correctly 2013-05-20 14:03:48 -06:00
README Correct typos in the documentation (Atsushi SAKAI) 2008-01-24 10:15:13 +00:00
README-hacking maint: relax git minimum version 2010-02-24 14:29:27 -05:00
TODO Update todo list file to point at bugzilla/website 2010-10-13 16:45:26 +01:00
autobuild.sh Remove python binding 2013-11-25 16:08:00 +00:00
autogen.sh autogen.sh: Correctly detect .git as a file 2013-08-29 13:19:45 +02:00
bootstrap maint: update to latest gnulib 2014-01-01 06:02:47 -07:00
bootstrap.conf Add helpers for getting env vars in a setuid environment 2013-10-21 14:03:52 +01:00
cfg.mk Add a rule for indenting labels 2014-03-25 14:58:41 +01:00
config-post.h build: fix build of virt-login-shell on systems with older gnutls 2013-10-22 09:41:50 -06:00
configure.ac Fix typo in configure.ac 2014-03-21 10:04:59 +01:00
libvirt.pc.in Add missing 'libvirt_lxc_api' variable in pkg-config file 2013-09-04 14:52:40 +01:00
libvirt.spec.in spec: move some dirs into appropriate subpackages 2014-03-17 16:43:24 +01:00
mingw-libvirt.spec.in Remove python binding 2013-11-25 16:08:00 +00:00
run.in Remove python binding 2013-11-25 16:08:00 +00:00

README

         LibVirt : simple API for virtualization

  Libvirt is a C toolkit to interact with the virtualization capabilities
of recent versions of Linux (and other OSes). It is free software
available under the GNU Lesser General Public License. Virtualization of
the Linux Operating System means the ability to run multiple instances of
Operating Systems concurrently on a single hardware system where the basic
resources are driven by a Linux instance. The library aim at providing
long term stable C API initially for the Xen paravirtualization but
should be able to integrate other virtualization mechanisms if needed.

Daniel Veillard <veillard@redhat.com>