Commit Graph

122 Commits

Author SHA1 Message Date
Michal Privoznik
d770618842 tests: Introduce virpcitest
Among with this test introduce virpcimock as we need to mock some
syscalls, e.g. redirect open() of a file under /sys/bus/pci to a
stub sysfs tree.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2013-11-04 14:56:56 +01:00
Martin Kletzander
52f42a9746 Ignore GNU Global tag files
... the same way we ignore other TAGS

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2013-10-23 10:06:21 +01:00
Daniel P. Berrange
5787f0b95e Fix flaw in detecting log format
The log message regex has been

[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{3}\+[0-9]{4}: [0-9]+: debug|info|warning|error :

The precedence of '|' is high though, so this is equivalent to matching

   [0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}:[0-9]{2}:[0-9]{2}\.[0-9]{3}\+[0-9]{4}: [0-9]+: debug

Or

   info

Or

   warning

Or

   error :

Which is clearly not what it should have done. This caused the code to
skip over things which are not log messages. The solution is to simply
add brackets.

A test case is also added to validate correctness.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-10-14 10:31:01 +01:00
Michal Privoznik
63857eb4a0 tests: Introduce qemucapabilitiestest
This test is there to ensure that our capabilities detection code isn't
broken somehow.

How to gather test data:

Firstly, the data is split into two separate files. The former (with
suffix .replies) contains all the qemu replies. This is very fragile as
introducing a new device can mean yet another monitor command and hence
edit of this file in the future. But there's no better way of doing
this. To get this data simply turn on debug logs and copy all the
QEMU_MONITOR_IO_PROCESS lines. But be careful to not copy incomplete
ones (yeah, we report some incomplete lines too). Long story short, at
the libvirtd startup, a dummy qemu is spawn to get all the capabilities.

The latter (with suffix .caps) contains capabilities XML. Just start a
domain and copy the corresponding part from its state XML file.
Including <qemuCaps> tag.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2013-10-01 11:13:36 +02:00
Doug Goldstein
7457cbe871 VMware: Make version parsing testable and add tests
This splits up the version parsing code into a callable API like QEMU
help/version string parsing so that we can test it as we need to add
additional patterns for newer versions/products.
2013-09-20 08:23:31 -05:00
Eric Blake
ceaa536d49 maint: ignore recently-added test
* .gitignore: Ignore metadatatest.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-09-17 10:24:41 -06:00
Eric Blake
7f626e478d build: use automake subdir-objects
Automake 2.0 will enable subdir-objects by default; in preparation
for that change, automake 1.14 outputs LOADS of warnings:

daemon/Makefile.am:38: warning: source file '../src/remote/remote_protocol.c' is in a subdirectory,
daemon/Makefile.am:38: but option 'subdir-objects' is disabled
automake-1.14: warning: possible forward-incompatibility.
automake-1.14: At least a source file is in a subdirectory, but the 'subdir-objects'
automake-1.14: automake option hasn't been enabled.  For now, the corresponding output
automake-1.14: object file(s) will be placed in the top-level directory.  However,
automake-1.14: this behaviour will change in future Automake versions: they will
automake-1.14: unconditionally cause object files to be placed in the same subdirectory
automake-1.14: of the corresponding sources.
automake-1.14: You are advised to start using 'subdir-objects' option throughout your
automake-1.14: project, to avoid future incompatibilities.
daemon/Makefile.am:38: warning: source file '../src/remote/lxc_protocol.c' is in a subdirectory,
daemon/Makefile.am:38: but option 'subdir-objects' is disabled
...

As automake 1.9 also supported this option, and the previous patches
fixed up the code base to work with it, it is safe to now turn it on
unconditionally.

* configure.ac (AM_INIT_AUTOMAKE): Enable subdir-objects.
* .gitignore: Ignore .dirstamp directories.
* src/Makefile.am (PDWTAGS, *-protocol-struct): Adjust to
new subdir-object location of .lo files.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-09-09 12:04:03 -06:00
Daniel P. Berrange
da13f2c70c Add documentation for access control system
This adds two new pages to the website, acl.html describing
the general access control framework and permissions models,
and aclpolkit.html describing the use of polkit as an
access control driver.

page.xsl is modified to support a new syntax

  <div id="include" filename="somefile.htmlinc"/>

which will cause the XSL transform to replace that <div>
with the contents of 'somefile.htmlinc'. We use this in
the acl.html.in file, to pull the table of permissions
for each libvirt object. This table is autogenerated
from the enums in src/access/viraccessperms.h by the
genaclperms.pl script.

newapi.xsl is modified so that the list of permissions
checks shown against each API will link to the description
of the permissions in acl.html

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-08-09 17:13:02 +01:00
Daniel P. Berrange
38550ae809 Add an example config file for virtlockd
The virtlockd daemon supports an /etc/libvirt/virtlockd.conf
config file, but we never installed a default config, nor
created any augeas scripts. This change addresses that omission.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-08-09 15:03:04 +01:00
Daniel P. Berrange
6ff0cffd55 Add a man page for virtlockd daemon
Create a virtlockd.pod.in file containing the man page
content for virtlockd.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-08-09 11:56:34 +01:00
Dan Walsh
54d69f540c Introduce a virt-login-shell binary
Add a virt-login-shell binary that can be set as a user's
shell, such that when they login, it causes them to enter
the LXC container with a name matching their user name.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-08-08 16:36:31 +01:00
Daniel P. Berrange
664ab2801d Add info about access control checks into API reference
So that app developers / admins know what access control checks
are performed for each API, this patch extends the API docs
generator to include details of the ACLs for each.

The gendispatch.pl script is extended so that it generates
a simple XML describing ACL rules, eg.

  <aclinfo>
    ...
    <api name='virConnectNumOfDomains'>
      <check object='connect' perm='search_domains'/>
      <filter object='domain' perm='getattr'/>
    </api>
    <api name='virDomainAttachDeviceFlags'>
      <check object='domain' perm='write'/>
      <check object='domain' perm='save' flags='!VIR_DOMAIN_AFFECT_CONFIG|VIR_DOMAIN_AFFECT_LIVE'/>
      <check object='domain' perm='save' flags='VIR_DOMAIN_AFFECT_CONFIG'/>
    </api>
    ...
  </aclinfo>

The newapi.xsl template loads the XML files containing the ACL
rules and generates a short block of HTML for each API describing
the parameter checks and return value filters (if any).

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-08-08 11:59:46 +01:00
Peter Krempa
5c94dfdd76 tests: Add qemuagenttest
Add a basic test framework with two simple tests to test guest agent
interaction.
2013-07-31 14:25:43 +02:00
Daniel P. Berrange
dff93f8cab Add API for calling systemd-machined's DBus API
To register virtual machines and containers with systemd-machined,
and thus have cgroups auto-created, we need to talk over DBus.
This is somewhat tedious code, so introduce a dedicated function
to isolate the DBus call in one place.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-22 13:09:58 +01:00
Daniel P. Berrange
834c9c9459 Introduce virDBusCallMethod & virDBusMessageRead methods
Doing DBus method calls using libdbus.so is tedious in the
extreme. systemd developers came up with a nice high level
API for DBus method calls (sd_bus_call_method). While
systemd doesn't use libdbus.so, their API design can easily
be ported to libdbus.so.

This patch thus introduces methods virDBusCallMethod &
virDBusMessageRead, which are based on the code used for
sd_bus_call_method and sd_bus_message_read. This code in
systemd is under the LGPLv2+, so we're license compatible.

This code is probably pretty unintelligible unless you are
familiar with the DBus type system. So I added some API
docs trying to explain how to use them, as well as test
cases to validate that I didn't screw up the adaptation
from the original systemd code.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-07-22 13:09:58 +01:00
Michal Privoznik
0fc12bca08 tests: Introduce qemuhotplugtest
As my punishment for the break in 7f15ebc7 (fixed in 752596b5dd) I'm
introducing this test to make sure it won't happen again. Currently,
only test for <graphics/> is supported.
2013-06-25 17:00:56 +02:00
Daniel P. Berrange
686026225e Auto-generate helpers for checking access control rules
Extend the 'gendispatch.pl' script to be able to generate
three new types of file.

- 'aclheader' - defines signatures of helper APIs for
  doing authorization checks. There is one helper API
  for each API requiring an auth check. Any @acl
  annotations result in a method being generated with
  a suffix of 'EnsureACL'. If the ACL check requires
  examination of flags, an extra 'flags' param will be
  present. Some examples

  extern int virConnectBaselineCPUEnsureACL(void);
  extern int virConnectDomainEventDeregisterEnsureACL(virDomainDefPtr domain);
  extern int virDomainAttachDeviceFlagsEnsureACL(virDomainDefPtr domain, unsigned int flags);

  Any @aclfilter annotations resuilt in a method being
  generated with a suffix of 'CheckACL'.

  extern int virConnectListAllDomainsCheckACL(virDomainDefPtr domain);

  These are used for filtering individual objects from APIs
  which return a list of objects

- 'aclbody' - defines the actual implementation of the
  methods described above. This calls into the access
  manager APIs. A complex example:

    /* Returns: -1 on error (denied==error), 0 on allowed */
    int virDomainAttachDeviceFlagsEnsureACL(virConnectPtr conn,
                                            virDomainDefPtr domain,
                                            unsigned int flags)
    {
        virAccessManagerPtr mgr;
        int rv;

        if (!(mgr = virAccessManagerGetDefault()))
            return -1;

        if ((rv = virAccessManagerCheckDomain(mgr,
                                              conn->driver->name,
                                              domain,
                                              VIR_ACCESS_PERM_DOMAIN_WRITE)) <= 0) {
            virObjectUnref(mgr);
            if (rv == 0)
                virReportError(VIR_ERR_ACCESS_DENIED, NULL);
            return -1;
        }
        if (((flags & (VIR_DOMAIN_AFFECT_CONFIG|VIR_DOMAIN_AFFECT_LIVE)) == 0) &&
            (rv = virAccessManagerCheckDomain(mgr,
                                              conn->driver->name,
                                              domain,
                                              VIR_ACCESS_PERM_DOMAIN_SAVE)) <= 0) {
            virObjectUnref(mgr);
            if (rv == 0)
                virReportError(VIR_ERR_ACCESS_DENIED, NULL);
            return -1;
        }
        if (((flags & (VIR_DOMAIN_AFFECT_CONFIG)) == (VIR_DOMAIN_AFFECT_CONFIG)) &&
            (rv = virAccessManagerCheckDomain(mgr,
                                              conn->driver->name,
                                              domain,
                                              VIR_ACCESS_PERM_DOMAIN_SAVE)) <= 0) {
            virObjectUnref(mgr);
            if (rv == 0)
                virReportError(VIR_ERR_ACCESS_DENIED, NULL);
            return -1;
        }
        virObjectUnref(mgr);
        return 0;
    }

- 'aclsyms' - generates a linker script to export the
   APIs to drivers. Some examples

  virConnectBaselineCPUEnsureACL;
  virConnectCompareCPUEnsureACL;

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-06-24 15:25:19 +01:00
Daniel P. Berrange
b904bba7f4 Add a policy kit access control driver
Add an access control driver that uses the pkcheck command
to check authorization requests. This is fairly inefficient,
particularly for cases where an API returns a list of objects
and needs to check permission for each object.

It would be desirable to use the polkit API but this links
to glib with abort-on-OOM behaviour, so can't be used. The
other alternative is to speak to dbus directly

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-06-24 15:24:36 +01:00
Eric Blake
de483052a2 maint: follow recommended practice for using LGPL
https://www.gnu.org/licenses/gpl-howto.html states:

You should also include a copy of the license itself somewhere in the
distribution of your program. All programs, whether they are released
under the GPL or LGPL, should include the text version of the GPL. In
GNU programs the license is usually in a file called COPYING.

If you are releasing your program under the LGPL, you should also
include the text version of the LGPL, usually in a file called
COPYING.LESSER. Please note that, since the LGPL is a set of
additional permissions on top of the GPL, it's important to include
both licenses so users have all the materials they need to understand
their rights.

* configure.ac (COPYING): No more games with non-git file.
* COPYING: New file, copied from gnulib.
* COPYING.LIB: Rename...
* COPYING.LESSER: ...to this.
* .gitignore: Track licenses in git.
* cfg.mk (exclude_file_name_regexp--sc_copyright_address): Tweak
rule.
* libvirt.spec.in (daemon, client, python): Reflect rename.

Signed-off-by: Eric Blake <eblake@redhat.com>
2013-05-20 14:15:21 -06:00
Ján Tomko
a011479d47 .gitignore: add fchosttest 2013-05-13 17:16:54 +02:00
Daniel P. Berrange
31989e66c6 Add a test case for the fdstream file read/write code
Add a test case which exercises the virFDStreamOpenFile
and virFDStreamCreateFile methods. Ensure that both the
synchronous and non-blocking iohelper code paths work.
This validates the regression recently fixed which
broke reading in non-blocking mode

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-05-10 19:57:18 +01:00
Daniel P. Berrange
d14524701a Add a test suite for cgroups functionality
Some aspects of the cgroups setup / detection code are quite subtle
and easy to break. It would greatly benefit from unit testing, but
this is difficult because the test suite won't have privileges to
play around with cgroups. The solution is to use monkey patching
via LD_PRELOAD to override the fopen, open, mkdir, access functions
to redirect access of cgroups files to some magic stubs in the
test suite.

Using this we provide custom content for the /proc/cgroup and
/proc/self/mounts files which report a fixed cgroup setup. We
then override open/mkdir/access so that access to the cgroups
filesystem gets redirected into files in a temporary directory
tree in the test suite build dir.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-15 17:35:31 +01:00
Daniel P. Berrange
15d8511b41 Add a test suite for keycode mapping functions
Validate that translations between different keycode sets
are functioning.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-04-08 10:03:20 +01:00
Gene Czarcinski
1cd2078c88 rename tests/conftest.c
To prevent confusion with configure's popular name
for a file, rename conftest.c to test_conf.c which
is consistent with the invoking test_conf.sh
Signed-off-by: Gene Czarcinski <gene@czarc.net>
2013-03-19 13:13:28 -06:00
Daniel P. Berrange
3aabe27247 Define internal APIs for managing identities
Introduce a local object virIdentity for managing security
attributes used to form a client application's identity.
Instances of this object are intended to be used as if they
were immutable, once created & populated with attributes

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-03-19 13:37:37 +00:00
Doug Goldstein
24cf110e48 Add autogenerated lxc_protocol.[ch] to gitignore
/src/lxc/lxc_protocol.[ch] is autogenerated so add it to .gitignore
2013-02-18 08:57:57 -06:00
Eric Blake
a18452d0d2 storage: test backing chain traversal
Testing our backing chain handling will make it much easier to
ensure that we avoid issues in the future.  If only I had written
this test before I first caused several regressions...

* tests/virstoragetest.c: New test.
* tests/Makefile.am (test_programs): Build it.
* .gitignore: Ignore new files.
2013-02-15 16:07:01 -07:00
Eric Blake
c6f1060ca7 util: add virendian.h macros
We have several cases where we need to read endian-dependent
data regardless of host endianness; rather than open-coding
these call sites, it will be nicer to funnel things through
a macro.

The virendian.h file can be expanded to add writer functions,
and/or 16-bit access patterns, if needed.  Also, if we need
to turn things into a function to avoid multiple evaluations
of buf, that can be done later.  But for now, a macro worked.

* src/util/virendian.h: New file.
* src/Makefile.am (UTIL_SOURCES): Ship it.
* tests/virendiantest.c: New test.
* tests/Makefile.am (test_programs, virendiantest_SOURCES): Run
the test.
* .gitignore: Ignore built file.
2013-02-12 09:00:15 -07:00
Martin Kletzander
3d36b1a4b0 Ignore '.trs' files
When doing checks with automake, there are '<testname>.trs' files left
behind, that might or might not be usable, however these show up in
'git status' even though we definitely don't want them to be tracked
in the repository'.  Automake adds the '--trs-files' option by default
since commit 0c81b43f711fb861f04227ced8dba889596d9c43 [1], which
consequently (from 1.13 in my case) started leaving these files behind
along with '<testname>.log' files as well (which we already ignore).

[1] http://git.savannah.gnu.org/gitweb/?p=automake.git;a=commitdiff;h=0c81b43
2013-01-30 09:37:03 +01:00
Daniel P. Berrange
9c9d4d32d3 Add a port allocator class
Introduce a virPortAllocator for managing TCP port allocations.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-01-16 11:02:58 +00:00
Michal Privoznik
584cd5c279 .gitignore: Sort alphabetically 2013-01-15 13:32:33 +01:00
Daniel P. Berrange
3d1596b048 Introduce an LXC specific public API & library
This patch introduces support for LXC specific public APIs. In
common with what was done for QEMU, this creates a libvirt_lxc.so
library and libvirt/libvirt-lxc.h header file.

The actual APIs are

  int virDomainLxcOpenNamespace(virDomainPtr domain,
                                int **fdlist,
                                unsigned int flags);

  int virDomainLxcEnterNamespace(virDomainPtr domain,
                                 unsigned int nfdlist,
                                 int *fdlist,
                                 unsigned int *noldfdlist,
                                 int **oldfdlist,
                                 unsigned int flags);

which provide a way to use the setns() system call to move the
calling process into the container's namespace. It is not
practical to write in a generically applicable manner. The
nearest that we could get to such an API would be an API which
allows to pass a command + argv to be executed inside a
container. Even if we had such a generic API, this LXC specific
API is still useful, because it allows the caller to maintain
the current process context, in particular any I/O streams they
have open.

NB the virDomainLxcEnterNamespace() API is special in that it
runs client side, so does not involve the internal driver API.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-01-14 13:58:34 +00:00
Daniel P. Berrange
907a39e735 Add a test suite for validating SELinux labelling
There are many aspects of the guest XML which result in the
SELinux driver applying file labelling. With the increasing
configuration options it is desirable to test this behaviour.
It is not possible to assume that the test suite has the
ability to set SELinux labels. Most filesystems though will
support extended attributes. Thus for the purpose of testing,
it is possible to extend the existing LD_PRELOAD hack to
override setfilecon() and getfilecon() to simply use the
'user.libvirt.selinux' attribute for the sake of testing.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-01-14 13:40:04 +00:00
Daniel P. Berrange
014afe6501 Rename lxc_protocol.x to lxc_monitor_protocol.x
To avoid confusion between the LXC driver <-> controller
monitor RPC protocol and the libvirt-lxc.so <-> libvirtd public
RPC protocol, rename the former to lxc_monitor_protocol.x

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2013-01-08 09:21:08 +00:00
Cole Robinson
ff93b865cd .gitignore: add tests/sysinfotest 2012-12-17 14:40:48 -05:00
Daniel P. Berrange
eb8268a4f6 Add a virtlockd client as a lock driver impl
This adds a 'lockd' lock driver which is just a client which
talks to the lockd daemon to perform all locking. This will
be the default lock driver for any hypervisor which needs one.

* src/Makefile.am: Add lockd.so plugin
* src/locking/lock_driver_lockd.c: Lockd driver impl

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-12-13 15:26:57 +00:00
Daniel P. Berrange
0e49b83912 Implement dispatch functions for lock protocol in virtlockd
Introduce a lock_daemon_dispatch.c file which implements the
server side dispatcher the RPC APIs previously defined in the
lock protocol.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-12-13 15:26:57 +00:00
Daniel P. Berrange
ad39fd83a8 Define a wire protocol for talking to the virtlockd daemon
The virtlockd daemon will be responsible for managing locks
on virtual machines. Communication will be via the standard
RPC infrastructure. This provides the XDR protocol definition

* src/locking/lock_protocol.x: Wire protocol for virtlockd
* src/Makefile.am: Include lock_protocol.[ch] in virtlockd

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-12-13 15:26:57 +00:00
Daniel P. Berrange
c57e3d8994 Introduce basic infrastructure for virtlockd daemon
The virtlockd daemon will maintain locks on behalf of libvirtd.
There are two reasons for it to be separate

 - Avoid risk of other libvirtd threads accidentally
   releasing fcntl() locks by opening + closing a file
   that is locked
 - Ensure locks can be preserved across libvirtd restarts.
   virtlockd will need to be able to re-exec itself while
   maintaining locks. This is simpler to achieve if its
   sole job is maintaining locks

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-12-13 15:26:57 +00:00
Cole Robinson
d13155c20c tools: Only install guests init script if --with-init=script=redhat
Most of this deals with moving the libvirt-guests.sh script which
does all the work to /usr/libexec, so it can be shared by both
systemd and traditional init. Previously systemd depended on
the script being in /etc/init.d

Required to fix https://bugzilla.redhat.com/show_bug.cgi?id=789747
2012-12-11 19:54:37 -05:00
Daniel P. Berrange
76c1fd33c8 Introduce APIs for splitting/joining strings
This introduces a few new APIs for dealing with strings.
One to split a char * into a char **, another to join a
char ** into a char *, and finally one to free a char **

There is a simple test suite to validate the edge cases
too. No more need to use the horrible strtok_r() API,
or hand-written code for splitting strings.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-11-30 20:05:43 +00:00
liguang
b27b712c24 gitignore: ignore more files
ignore cscope.in.out, cscope.po.out

Signed-off-by: liguang <lig.fnst@cn.fujitsu.com>
2012-11-05 15:56:42 +01:00
Michal Privoznik
ffa62d06a8 gitignore: Ignore 'tags' 2012-10-31 16:47:34 +01:00
Peter Krempa
41bf06e96a maint: Sort .gitignore
Sorting of the .gitignore file was broken after the last addition. After
a clean build the scripts re-sort it making the working tree dirty.
2012-10-26 14:39:55 +02:00
Eric Blake
caea10bf75 maint: ignore unsaved emacs files
I did a 'git add .', then realized that it ended up trying to
add the emacs lock file for a corresponding file that I had not
yet saved all my edits; thankfully I noticed it in time.  Since
we already exclude other temporary files, this makes the most
sense for preventing such a mistake from actually hitting upstream.

* .gitignore: Add .#* to the exclude list.
2012-10-25 16:12:46 -06:00
Cole Robinson
7b21981cdb Autogenerate AUTHORS
AUTHORS.in tracks the maintainers, as well as some folks who were
previously in AUTHORS but don't have a git commit with proper
attribution.

Generated output is sorted alphabetically and lacks pretty spacing, so
tweak AUTHORS.in to follow the same format.

Additionally, drop the syntax-check rule that previously validated
AUTHORS against git log.
2012-10-19 12:44:56 -04:00
Daniel P. Berrange
eca72d4759 Introduce an internal API for handling file based lockspaces
The previously introduced virFile{Lock,Unlock} APIs provide a
way to acquire/release fcntl() locks on individual files. For
unknown reason though, the POSIX spec says that fcntl() locks
are released when *any* file handle referring to the same path
is closed. In the following sequence

  threadA: fd1 = open("foo")
  threadB: fd2 = open("foo")
  threadA: virFileLock(fd1)
  threadB: virFileLock(fd2)
  threadB: close(fd2)

you'd expect threadA to come out holding a lock on 'foo', and
indeed it does hold a lock for a very short time. Unfortunately
when threadB does close(fd2) this releases the lock associated
with fd1. For the current libvirt use case for virFileLock -
pidfiles - this doesn't matter since the lock is acquired
at startup while single threaded an never released until
exit.

To provide a more generally useful API though, it is necessary
to introduce a slightly higher level abstraction, which is to
be referred to as a "lockspace".  This is to be provided by
a virLockSpacePtr object in src/util/virlockspace.{c,h}. The
core idea is that the lockspace keeps track of what files are
already open+locked. This means that when a 2nd thread comes
along and tries to acquire a lock, it doesn't end up opening
and closing a new FD. The lockspace just checks the current
list of held locks and immediately returns VIR_ERR_RESOURCE_BUSY.

NB, the API as it stands is designed on the basis that the
files being locked are not being otherwise opened and used
by the application code. One approach to using this API is to
acquire locks based on a hash of the filepath.

eg to lock /var/lib/libvirt/images/foo.img the application
might do

   virLockSpacePtr lockspace = virLockSpaceNew("/var/lib/libvirt/imagelocks");
   lockname = md5sum("/var/lib/libvirt/images/foo.img");
   virLockSpaceAcquireLock(lockspace, lockname);

NB, in this example, the caller should ensure that the path
is canonicalized before calculating the checksum.

It is also possible to do locks directly on resources by
using a NULL lockspace directory and then using the file
path as the lock name eg

   virLockSpacePtr lockspace = virLockSpaceNew(NULL);
   virLockSpaceAcquireLock(lockspace, "/var/lib/libvirt/images/foo.img");

This is only safe to do though if no other part of the process
will be opening the files. This will be the case when this
code is used inside the soon-to-be-reposted virlockd daemon

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-10-16 15:45:55 +01:00
Cole Robinson
e1019e9e84 Only keep one polkit rules file
Just tweak it at build time depending on what polkit version we are
building for.
2012-10-14 15:21:18 -04:00
Richard W.M. Jones
5090c576e3 Add a ./run script for running programs from the local directory.
With this script you can run libvirt programs without needing to
install them first.  You just have to do for example:

  ./run ./tools/virsh [args ...]

If you are already in the tools/ subdirectory, then the following
command will also work:

  ../run ./virsh [...]

You can also run the C programs under valgrind like this:

  ./run valgrind [valgrind opts...] ./program

or under gdb:

  ./run gdb --args ./program

This also works with sudo (eg. if you need root access for libvirt):

  sudo ./run ./tools/virsh list --all

Derived from libguestfs and simplified.  The ./run script in
libguestfs is much more sophisticated:

https://github.com/libguestfs/libguestfs/blob/master/run.in
2012-09-18 10:59:16 +01:00
Richard W.M. Jones
481dfbaed4 gitignore: Ignore .gdb_history file. 2012-09-18 10:03:52 +01:00