build: fix bootstrap on RHEL

Commit 8fe455fd364cd7462e02170084c45a58ee302cc3 tried to work around
a regression introduced in upstream gnulib that requires gettext 0.18
or newer on all projects using bootstrap, by making libvirt require
gettext 0.18.  But this fails on RHEL 6.2, which still ships gettext
0.17.  Revert that change, and instead, import the latest round of
gnulib updates that fix that problem properly.

If you have already built in the window where libvirt required 0.18,
be aware that incremental updates may run into problems: this is
because 'autopoint --force' will not downgrade m4/po.m4 back to an
older version, but it must be downgraded back to 0.17 levels to work
with this patch.  You may either manually remove that file then rerun
bootstrap, or it may prove easier to just clean up all non-git files
to start from a clean slate.

* bootstrap.conf: Revert minimum gettext back to 0.17.
* configure.ac: Likewise.
* .gnulib: Update to latest, for bootstrap fixes.
* bootstrap: Resync from gnulib.
util: fix crash when starting macvtap interfaces

This patch resolves https://bugzilla.redhat.com/show_bug.cgi?id=815270

The function virNetDevMacVLanVPortProfileRegisterCallback() takes an
arg "virtPortProfile", and was checking it for non-NULL before using
it. However, the prototype for
virNetDevMacVLanPortProfileRegisterCallback had marked that arg with
ATTRIBUTE_NONNULL(). Contrary to what one may think,
ATTRIBUTE_NONNULL() does not provide any guarantee that an arg marked
as such really is always non-null; the only effect to the code
generated by gcc, is that gcc *assumes* it is non-NULL; this results
in, for example, the check for a non-NULL value being optimized out.

(Unfortunately, this code removal only occurs when optimization is
enabled, and I am in the habit of doing local builds with optimization
off to ease debugging, so the bug didn't show up in my earlier local
testing).

In general, virPortProfile might always be NULL, so it shouldn't be
marked as ATTRIBUTE_NONNULL. One other function prototype made this
same error, so this patch fixes it as well.
keepalive: Add ability to disable keepalive messages

The docs for virConnectSetKeepAlive() advertise that this function
should be able to disable keepalives on negative or zero interval time.

This patch removes the check that prohibited this and adds code to
disable keepalives on negative/zero interval.

* src/libvirt.c: virConnectSetKeepAlive(): - remove check for negative
                                             values
* src/rpc/virnetclient.c
* src/rpc/virnetclient.h: - add virNetClientKeepAliveStop() to disable
                            keepalive messages
* src/remote/remote_driver.c: remoteSetKeepAlive(): -add ability to
                                                     disable keepalives
qemu: Preserve original error during migration

In some cases (spotted with broken connection during tunneled migration)
we were overwriting the original error with worse or even misleading
errors generated when we were cleaning up after failed migration.
rpc: Discard non-blocking calls only when necessary

Currently, non-blocking calls are either sent immediately or discarded
in case sending would block. This was implemented based on the
assumption that the non-blocking keepalive call is not needed as there
are other calls in the queue which would keep the connection alive.
However, if those calls are no-reply calls (such as those carrying
stream data), the remote party knows the connection is alive but since
we don't get any reply from it, we think the connection is dead.

This is most visible in tunnelled migration. If it happens to be longer
than keepalive timeout (30s by default), it may be unexpectedly aborted
because the connection is considered to be dead.

With this patch, we only discard non-blocking calls when the last call
with a thread is completed and thus there is no thread left to keep
sending the remaining non-blocking calls.
qemu: Fix detection of failed migration

When QEMU reported failed or canceled migration, we correctly detected
it but didn't really consider it as an error condition and migration
protocol just went on. Luckily, some of the subsequent steps eventually
failed end we reported an (unrelated and mostly random) error back to
the caller.
qemu: Avoid bogus error at the end of tunnelled migration

Once qemu monitor reports migration has completed, we just closed our
end of the pipe and let migration tunnel die. This generated bogus error
in case we did so before the thread saw EOF on the pipe and migration
was aborted even though it was in fact successful.

With this patch we first wake up the tunnel thread and once it has read
all data from the pipe and finished the stream we close the
filedescriptor.

A small additional bonus of this patch is that real errors reported
inside qemuMigrationIOFunc are not overwritten by virStreamAbort any
more.
util: fix error messages in virNetlinkEventServiceStart

Some of the error messages in this function should have been
virReportSystemError (since they have an errno they want to log), but
were mistakenly written as netlinkError, which expects a libvirt error
code instead. The result was that when one of the errors was
encountered, "No error message provided" would be printed instead of
something meaningful (see
https://bugzilla.redhat.com/show_bug.cgi?id=816465 for an example).
nwfilter: address coverity findings

This patch addresses the following coverity findings:

/libvirt/src/conf/nwfilter_params.c:157:
deref_parm: Directly dereferencing parameter "val".

/libvirt/src/conf/nwfilter_params.c:473:
negative_returns: Using variable "iterIndex" as an index to array "res->iter".

/libvirt/src/nwfilter/nwfilter_ebiptables_driver.c:2891:
unchecked_value: No check of the return value of "virAsprintf(&protostr, "-d 01:80:c2:00:00:00 ")".

/libvirt/src/nwfilter/nwfilter_ebiptables_driver.c:2894:
unchecked_value: No check of the return value of "virAsprintf(&protostr, "-p 0x%04x ", l3_protocols[protoidx].attr)".

/libvirt/src/nwfilter/nwfilter_ebiptables_driver.c:3590:
var_deref_op: Dereferencing null variable "inst".
nwfilter: address more coverity findings

This patch addresses the following coverity findings:

/libvirt/src/conf/nwfilter_params.c:390:
var_assigned: Assigning: "varValue" = null return value from "virHashLookup".

/libvirt/src/conf/nwfilter_params.c:392:
dereference: Dereferencing a pointer that might be null "varValue" when calling "virNWFilterVarValueGetNthValue".

/libvirt/src/conf/nwfilter_params.c:399:
dereference: Dereferencing a pointer that might be null "tmp" when calling "virNWFilterVarValueGetNthValue".
macvtap: fix a typo

Below patch fixes the following coverity findings

Error: OVERRUN_STATIC:
/libvirt/src/qemu/qemu_command.c:152:
overrun-buffer-val: Overrunning static array "net->mac" of size 6 bytes by passing it as an argument to a function which indexes it at byte position 15.
/libvirt/src/util/virnetdevmacvlan.c:948:
access_dbuff_const: Calling "virNetDevMacVLanVPortProfileRegisterCallback" indexes array "macaddress" at byte position 15.
/libvirt/src/util/virnetdevmacvlan.c:773:
access_dbuff_const: Calling "memcpy" indexes array "macaddress" with index "16UL" at byte position 15.

Error: OVERRUN_STATIC:
/libvirt/src/qemu/qemu_migration.c:2744:
overrun-buffer-val: Overrunning static array "net->mac" of size 6 bytes by passing it as an argument to a function which indexes it at byte position 15.
/libvirt/src/util/virnetdevmacvlan.c:773:
access_dbuff_const: Calling "memcpy" indexes array "macaddress" with index "16UL" at byte position 15.

Error: OVERRUN_STATIC:
/libvirt/src/qemu/qemu_driver.c:435:
overrun-buffer-val: Overrunning static array "net->mac" of size 6 bytes by passing it as an argument to a function which indexes it at byte position 15.
/libvirt/src/util/virnetdevmacvlan.c:1036:
access_dbuff_const: Calling "virNetDevMacVLanVPortProfileRegisterCallback" indexes array "macaddress" at byte position 15.
/libvirt/src/util/virnetdevmacvlan.c:773:
access_dbuff_const: Calling "memcpy" indexes array "macaddress" with index "16UL" at byte position 15.
qemu: improve errors related to offline domains

https://bugzilla.redhat.com/show_bug.cgi?id=816662 pointed out
that attempting 'virsh blockpull' on an offline domain gave a
misleading error message about qemu lacking support for the
operation, even when qemu was specifically updated to support it.
The real problem is that we have several capabilities that are
only determined when starting a domain, and therefore are still
clear when first working with an inactive domain (namely, any
capability set by qemuMonitorJSONCheckCommands).

While this patch was able to hoist an existing check in one of the
three culprits, it had to add redundant checks in the other two
places (because you always have to check for an active domain after
obtaining a VM job lock, but the capability bits were being checked
prior to obtaining the job lock).

Someday it would be nice to patch libvirt to cache the set of
capabilities per qemu binary (as determined by inode and timestamp),
rather than re-probing the binary every time a domain is started,
and to teach the cache how to query the monitor during the one
time the probe is made rather than having to wait until a guest
is started; then, a capability probe would succeed even for offline
guests because it just refers to the cache, and the single check for
an active domain after grabbing the job lock would be sufficient.
But since that will involve a lot more coding, I'm happy to go
with this simpler solution for an immediate solution.

* src/qemu/qemu_driver.c (qemuDomainPMSuspendForDuration)
(qemuDomainSnapshotCreateXML, qemuDomainBlockJobImpl): Check for
offline state before checking an online-only cap.
qemu: Use common helper when probing qemu capabilities

QEMU binary is called several times when we probe different kinds of
capabilities the binary supports. This patch introduces new common
helper so that all probes use a consistent way of invoking qemu.
configure: Use ustar format for dist tarball

Since for stable releases, some test files were over the 99 char
limit for traditional tar filenames.

Suggested by Osier here:
https://www.redhat.com/archives/libvir-list/2012-April/msg01435.html

Signed-off-by: Cole Robinson <crobinso@redhat.com>
docs: Serialize running apibuild.py

Use a witness file approach like we do for python/generator.py,
as suggested by Eric. Fixes the build issue reported here:

https://www.redhat.com/archives/libvir-list/2012-April/msg01435.html

Signed-off-by: Cole Robinson <crobinso@redhat.com>
python: Fix doc directory name for stable releases

We were using the libvirt release version (like 0.9.11) and not
the configure version (which for stable releases is 0.9.11.X)

Most other places got this right so hopefully that's all the fallout
from the version format change :)

Signed-off-by: Cole Robinson <crobinso@redhat.com>
lxc: Fix coverity findings

Error: UNINIT:
/libvirt/src/lxc/lxc_driver.c:1412:
var_decl: Declaring variable "fd" without initializer.
/libvirt/src/lxc/lxc_driver.c:1460:
uninit_use_in_call: Using uninitialized value "fd" when calling "virFileClose".
/libvirt/src/util/virfile.c:50:
read_parm: Reading a parameter value.

Error: DEADCODE:
/libvirt/src/lxc/lxc_controller.c:960:
dead_error_condition: On this path, the condition "ret == 4" cannot be true.
/libvirt/src/lxc/lxc_controller.c:959:
at_most: After this line, the value of "ret" is at most -1.
/libvirt/src/lxc/lxc_controller.c:959:
new_values: Noticing condition "ret < 0".
/libvirt/src/lxc/lxc_controller.c:961:
dead_error_line: Execution cannot reach this statement "continue;".

Error: UNINIT:
/libvirt/src/lxc/lxc_controller.c:1104:
var_decl: Declaring variable "consoles" without initializer.
/libvirt/src/lxc/lxc_controller.c:1237:
uninit_use: Using uninitialized value "consoles".
blockjob: fix block-stream bandwidth race

With RHEL 6.2, virDomainBlockPull(dom, dev, bandwidth, 0) has a race
with non-zero bandwidth: there is a window between the block_stream
and block_job_set_speed monitor commands where an unlimited amount
of data was let through, defeating the point of a throttle.

This race was first identified in commit a9d3495e, and libvirt was
able to reduce the size of the window for that race.  In the meantime,
the qemu developers decided to fix things properly; per this message:
https://lists.gnu.org/archive/html/qemu-devel/2012-04/msg03793.html
the fix will be in qemu 1.1, and changes block-job-set-speed to use
a different parameter name, as well as adding a new optional parameter
to block-stream, which eliminates the race altogether.

Since our documentation already mentioned that we can refuse a non-zero
bandwidth for some hypervisors, I think the best solution is to do
just that for RHEL 6.2 qemu, so that the race is obvious to the user
(anyone using stock RHEL 6.2 binaries won't have this patch, and anyone
building their own libvirt with this patch for RHEL can also rebuild
qemu to get the modern semantics, so it is no real loss in behavior).

Meanwhile the code must be fixed to honor actual qemu 1.1 naming.
Rename the parameter to 'modern', since the naming difference now
covers more than just 'async' block-job-cancel.  And while at it,
fix an unchecked integer overflow.

* src/qemu/qemu_monitor.h (enum BLOCK_JOB_CMD): Drop unused value,
rename enum to match conventions.
* src/qemu/qemu_monitor.c (qemuMonitorBlockJob): Reflect enum rename.
* src/qemu_qemu_monitor_json.h (qemuMonitorJSONBlockJob): Likewise.
* src/qemu/qemu_monitor_json.c (qemuMonitorJSONBlockJob): Likewise,
and support difference between RHEL 6.2 and qemu 1.1 block pull.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Reject
bandwidth during pull with too-old qemu.
* src/libvirt.c (virDomainBlockPull, virDomainBlockRebase):
Document this.
More coverity findings addressed

More bug extermination in the category of:

Error: CHECKED_RETURN:

/libvirt/src/conf/network_conf.c:595:
check_return: Calling function "virAsprintf" without checking return value (as is done elsewhere 515 out of 543 times).

/libvirt/src/qemu/qemu_process.c:2780:
unchecked_value: No check of the return value of "virAsprintf(&msg, "was paused (%s)", virDomainPausedReasonTypeToString(reason))".

/libvirt/tests/commandtest.c:809:
check_return: Calling function "setsid" without checking return value (as is done elsewhere 4 out of 5 times).

/libvirt/tests/commandtest.c:830:
unchecked_value: No check of the return value of "virTestGetDebug()".

/libvirt/tests/commandtest.c:831:
check_return: Calling function "virTestGetVerbose" without checking return value (as is done elsewhere 41 out of 42 times).

/libvirt/tests/commandtest.c:833:
check_return: Calling function "virInitialize" without checking return value (as is done elsewhere 18 out of 21 times).


One note about the error in commandtest line 809: setsid() seems to fail when running the test -- could be removed ?
qemu_agent: Report error class at least

Currently, qemu GA is not providing 'desc' field for errors like
we are used to from qemu monitor. Therefore, we fall back to this
general 'unknown error' string. However, GA is reporting 'class' which
is not perfect, but much more helpful than generic error string.
Thus we should fall back to class firstly and if even no class
is presented, then we can fall back to that generic string.

Before this patch:
virsh # dompmsuspend --target mem f16
error: Domain f16 could not be suspended
error: internal error unable to execute QEMU command
'guest-suspend-ram': unknown QEMU command error

After this patch:
virsh # dompmsuspend --target mem f16
error: Domain f16 could not be suspended
error: internal error unable to execute QEMU command
'guest-suspend-ram': The command has not been found