Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

As part of the goal to get away from doing string matching on
filenames when deciding whether to emit a log message, turn
the virLogSource enum into a struct which contains a log
"name". There will eventually be one virLogSource instance
statically declared per source file. To minimise churn in this
commit though, a single global instance is used.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The error reporting code will invoke a callback when any error
is raised and the default callback will print to stderr. The
virRaiseErrorFull method also sends all error messages on to the
logging code, which also prints to stderr by default. To avoid
duplicated data on stderr, the logging code has some logic to
skip emission when no log outputs are configured, which checks
whether the virLogSource == VIR_LOG_FROM_ERROR.

Meanwhile the libvirtd daemon can register another callback which
is used to reduce log message priority from error to a lower level.
When this is used we do want messages to end up on stderr, so the
error code will conditionally use either VIR_LOG_FROM_FILE or
VIR_LOG_FROM_ERROR depending on whether such a callback is provided.

This will all complicate later refactoring. By pushing the checks
for whether a log output is present up a level into the error code,
the special cases can be isolated in one place.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

GNULIB provides APIs for calculating md5 and sha256 hashes,
but these APIs only return you raw byte arrays. Most users
in libvirt want the hash in printable string format. Add
some helper APIs in util/vircrypto.{c,h} for doing this.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When a virError is raised, pass the error domain and code
onto the systemd journald using metadata fields.

This allows error messages to be queried by code eg

  $ journalctl LIBVIRT_CODE=43
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

At this point it has a limited functionality and is highly
experimental. Supported domain operations are:

  * define
  * start
  * destroy
  * dumpxml
  * dominfo

It's only possible to have only one disk device and only one
network, which should be of type bridge.

Some of our operation denied messages are outright stupid; for
example, if virIdentitySetAttr fails:

error: operation Identity attribute is already set forbidden for read only access

This patch fixes things to a saner:

error: operation forbidden: Identity attribute is already set

It also consolidates the most common usage pattern for operation
denied errors: read-only connections preventing a public API.  In
this case, 'virsh -r -c test:///default destroy test' changes from:

error: operation virDomainDestroy forbidden for read only access

to:

error: operation forbidden: read only access prevents virDomainDestroy

Note that we were previously inconsistent on which APIs used
VIR_FROM_DOM (such as virDomainDestroy) vs. VIR_FROM_NONE (such as
virDomainPMSuspendForDuration).  After this patch, all uses
consistently use VIR_FROM_NONE, on the grounds that it is unlikely
that a caller learning that a call is denied can do anything in
particular with extra knowledge which error domain the call belongs
to (similar to what we did in commit baa72449).

* src/util/virerror.c (virErrorMsg): Rework OPERATION_DENIED error
message.
* src/internal.h (virCheckReadOnlyGoto): New macro.
* src/util/virerror.h (virReportRestrictedError): New macro.
* src/libvirt-lxc.c: Use new macros.
* src/libvirt-qemu.c: Likewise.
* src/libvirt.c: Likewise.
* src/locking/lock_daemon.c (virLockDaemonClientNew): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

We currently have other error codes in singular form, e.g.
VIR_ERR_NETWORK_EXIST. Cleanup the previous patch to match the form.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

I created a storage volume(eg: test) from a storage pool(eg:vg10) using
the following command:"virsh vol-create-as --pool vg10 --name test --capacity 300M."
When I re-executed the above command, the output was as the following:
"error: Failed to create vol test
 error: Storage volume not found: storage vol 'test' already exists"

I think the output "Storage volume not found" is not appropriate. Because in fact storage
vol test has been found at this time. And then I think virErrorNumber should includes
VIR_ERR_STORAGE_EXIST which can also be used elsewhere. So I make this patch. The result
is as following:
"error: Failed to create vol test
 error: storage volume 'test' exists already"

As we do for other errors with an extra string.

Add virErrorSetErrnoFromLastError and virLastErrorIsSystemErrno
to simplify code which wants to handle system errors in a more
graceful fashion.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NDaniel P. Berrange <berrange@redhat.com>

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: NDaniel P. Berrange <berrange@redhat.com>

Actually, I'm turning this function into a macro as filename,
function name and line number needs to be passed. The new
function virAsprintfInternal is introduced with the extended set
of arguments.

Similarly to VIR_STRDUP, we want the OOM error to be reported in
VIR_ALLOC and friends.

This patch introduces the virAccessManagerPtr class as the
interface between virtualization drivers and the access
control drivers. The viraccessperm.h file defines the
various permissions that will be used for each type of object
libvirt manages
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Apps using libvirt will often have code like

   if (virXXXX() < 0) {
      virErrorPtr err = virGetLastError();
      fprintf(stderr, "Something failed: %s\n",
              err && err->message ? err->message :
              "unknown error");
      return -1;
   }

Checking for a NULL error object or message leads to very
verbose code. A virGetLastErrorMessage() helper from libvirt
can simplify this to

   if (virXXXX() < 0) {
      fprintf(stderr, "Something failed: %s\n",
              virGetLastErrorMessage());
      return -1;
   }
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.

Add a virCgroupIsolateMount method which looks at where the
current process is place in the cgroups (eg /system/demo.lxc.libvirt)
and then remounts the cgroups such that this sub-directory
becomes the root directory from the current process' POV.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NDaniel P. Berrange <berrange@redhat.com>

BZ:https://bugzilla.redhat.com/show_bug.cgi?id=912021
Without error handler set, virDefaultErrorFunc will be called, the
error message is prefixed with "libvir:". It become a little better
by using prefix "libvirt:" when working with upper application.

For example:
1, stop libvirtd daemon
2, run virt-top.
libvir: XML-RPC error : Failed to connect \
        socket to '/var/run/libvirt/libvirt-sock-ro': \
        No such file or directory
libvirt: VIR_ERR_SYSTEM_ERROR: VIR_FROM_RPC: \
        Failed to connect socket to '/var/run/libvirt/libvirt-sock-ro': \
        No such file or directory

Way back when I started making changes for Coverity messages my first set
were to a bunch of CHECKED_RETURN errors.  In particular virAsprintf() had
a few callers that Coverity noted didn't check their return (although some
did check if the buffer being printed to was NULL or not).

It was suggested at the time as a further patch an ATTRIBUTE_RETURN_CHECK
should be added to virAsprintf(), see:

https://www.redhat.com/archives/libvir-list/2013-January/msg00120.html

This patch does that and fixes a few more instances not found by Coverity
that failed the check.

To be able todo controlled shutdown/reboot of containers an
API to talk to init via /dev/initctl is required. Fortunately
this is quite straightforward to implement, and is supported
by both sysvinit and systemd. Upstart support for /dev/initctl
is unclear.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

... and update all users.  No change in functionality, the parameter
will be used later.

The metadata representation is as minimal as possible, but requires
the caller to allocate an array on stack explicitly.

The alternative of using varargs in the virLogMessage() callers:
* Would not allow the caller to optionally omit some metadata elements,
  except by having two calls to virLogMessage.
* Would not be as type-safe (e.g. using int vs. size_t), and the compiler
  wouldn't be able to do type checking
* Depending on parameter order:
  a) virLogMessage(..., message format, message params...,
                   metadata..., NULL)
     can not be portably implemented (parse_printf_format() is a glibc
     function)
  b) virLogMessage(..., metadata..., NULL,
                   message format, message params...)
     would prevent usage of ATTRIBUTE_FMT_PRINTF and the associated
     compiler checking.
Signed-off-by: NMiloslav Trmač <mitr@redhat.com>

The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

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: NDaniel P. Berrange <berrange@redhat.com>

The 'const char *category' parameter only has a few possible
values now that the filename has been separated. Turn this
parameter into an enum instead.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Currently the logging APIs have a 'const char *category' parameter
which indicates where the log message comes from. This is typically
a combination of the __FILE__ string and other prefix. Split the
__FILE__ off into a dedicated parameter so it can passed to the
log outputs
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

Currently, when guest agent is configured but not responsive
(e.g. due to appropriate service not running in the guest)
we return VIR_ERR_INTERNAL_ERROR. Both are wrong. Therefore
we need to introduce new error code to reflect this case.

This patch adds helper functions that enable us to use libssh2 in
conjunction with libvirt's virNetSockets for ssh transport instead of
spawning "ssh" client process.

This implemetation supports tunneled plaintext, keyboard-interactive,
private key, ssh agent based and null authentication. Libvirt's Auth
callback is used for interaction with the user. (Keyboard interactive
authentication, adding of host keys, private key passphrases). This
enables seamless integration into the application using libvirt. No
helpers as "ssh-askpass" are needed.

Reading and writing of OpenSSH style "known_hosts" files is supported.

Communication is done using SSH exec channel, where the user may specify
arbitrary command to be executed on the remote side and reads and writes
to/from stdin/out are sent through the ssh channel. Usage of stderr is
not (yet) supported.

Move the functions the parse/format, and validate PCI addresses to
their own file so they can be conveniently used in other places
besides device_conf.c

Refactoring existing code without causing any functional changes to
prepare for new code.

This patch makes the code reusable.
Signed-off-by: NShradha Shah <sshah@solarflare.com>

This patch introduces a new error code VIR_ERR_OPERATION_UNSUPPORTED to
mark error messages regarding operations that failed due to lack of
support on the hypervisor or other than libvirt issues.

The code is first used in reporting error if qemu does not support block
IO tuning variables yielding error message:
error: Unable to get block I/O throttle parameters
error: Operation not supported: block_io_throttle field
'total_bytes_sec' missing in qemu's output

instead of:
error: Unable to get block I/O throttle parameters
error: internal error cannot read total_bytes_sec