To prevent the error messages in cfg.mk from triggering the very
same rules they're supposed to explain, we split the message in
the middle of a symbol name, ending up with stuff like
'I am a me'ssage
Instead of relying on these quotation tricks, simply exclude
cfg.mk from the relevant checks.
Being consistent is nice, especially when it comes to defining our
regular expression, where using single quotes instead of double
quotes allows us to leave out a few backslashes.
Changing this required altering a few error messages.
The only remaining use of double quotes is one where they are
actually required for the check to work.
While we have a wiki page describing the feature [1] since the
feature is distributed in our .tar.gz we ought to document it. So
I went ahead, copied the wiki page and reformatted so it fits our
docs coding style.
1: http://wiki.libvirt.org/page/NSS_module
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
After 9c17d665fd the tap device for ethernet network type is
automatically precreated before spawning qemu. Problem is, the
qemuxml2argvtest wasn't updated and thus is failing. Because of
all the APIs that new code is calling, I had to mock a lot. Also,
since the tap FDs are labeled separately from the rest of the
devices/files I had to enable NOP security driver for the test
too.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
As mock libraries are not to be linked against libvirt, the
sc_prohibit_close syntax-check rule does not apply.
This fixes a syntax-check failure introduced by commit a03cbfe0fb.
There might be cases, like with typed params, where triggering this check isn't
desirable. But including the whole module in the exception regex is not always
to right way of doing things. By adding an option to manually disable this check
on a specific occurrence, the module itself will still be checked against the
rule.
As it turned out, we need to share some enums and declarations between
libvirt.h and libvirt-admin.h, but since our policy forbids direct includes of
libvirt*.h, there has to be some header exempt from this rule. This patch moves
the relevant part of code from libvirt.h.in to libvirt-common.h.in. Moreover,
since there is no need to have libvirt.h generated anymore, introduce a new
header libvirt.h which was previosly ignored from git and make the common
header ignored and generated instead.
Currently the QEMU stdout/stderr streams are written directly to
a regular file (eg /var/log/libvirt/qemu/$GUEST.log). While those
can be rotated by logrotate (using copytruncate option) this is
not very efficient. It also leaves open a window of opportunity
for a compromised/broken QEMU to DOS the host filesystem by
writing lots of text to stdout/stderr.
This makes it possible to connect the stdout/stderr file handles
to a pipe that is provided by virtlogd. The virtlogd daemon will
read from this pipe and write data to the log file, performing
file rotation whenever a pre-determined size limit is reached.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Copy the virtlockd codebase across to form the initial virlogd
code. Simple search & replace of s/lock/log/ and gut the remote
protocol & dispatcher. This gives us a daemon that starts up
and listens for connections, but does nothing with them.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Back in
commit bd6c46fa0c
Author: Juerg Haefliger <juerg.haefliger@hp.com>
Date: Mon Jan 31 06:42:57 2011 -0500
tests: handle backspace-newline pairs in test input files
all the test argv files were line wrapped so that the args
were less than 80 characters.
The way the line wrapping was done turns out to be quite
undesirable, because it often leaves multiple parameters
on the same line. If we later need to add or remove
individual parameters, then it leaves us having to redo
line wrapping.
This commit changes the line wrapping so that every
single "-param value" is one its own new line. If the
"value" is still too long, then we break on ',' or ':'
or ' ' as needed.
This means that when we come to add / remove parameters
from the test files line, the patch diffs will only
ever show a single line added/removed which will greatly
simplify review work.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
We have macros for both positive and negative string matching.
Therefore there is no need to use !STREQ or !STRNEQ. At the same
time as we are dropping this, new syntax-check rule is
introduced to make sure we won't introduce it again.
Signed-off-by: Ishmanpreet Kaur Khera <khera.ishman@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
In order to share as much virsh' logic as possible with upcomming
virt-admin client we need to split virsh logic into virsh specific and
client generic features.
Since majority of virsh methods should be generic enough to be used by
other clients, it's much easier to rename virsh specific data to virshX
than doing this vice versa. It moved generic virsh commands (including info
and opts structures) to generic module vsh.c.
Besides renaming methods and structures, this patch also involves introduction
of a client specific control structure being referenced as private data in the
original control structure, introduction of a new global vsh Initializer,
which currently doesn't do much, but there is a potential for added
functionality in the future.
Lastly it introduced client hooks which are especially necessary during
client connecting phase.
For this to pe properly separated from other protocols used by the
server, there is second server added which allows access to the whole
virNetDaemon to its clients.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Initial scratch of the admin library. It has its own virAdmConnectPtr
that inherits from virAbstractConnectPtr and thus trivially supports
error reporting.
There's pkg-config file added and spec-file adjusted as well.
Since the library should be "minimalistic" and not depend on any other
library, the list of files is especially crafted for it. Most of them
could've been put to it's own sub-libraries that would be LIBADD'd to
libvirt_util, libvirt_net_rpc and libvirt_setuid_rpc_client to minimize
the number of object files being built, but that's a refactoring that
isn't the orginal aim of this commit.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
In order not to bring in any link dependencies, bridge driver doesn't
use the usual stubs as other conditionally-built code does. However,
having the function as a macro imposes a problem with possibly unused
variables if just defined as "0". This was worked around by using
(dom=dom, iface=iface, 0) which should act like a 0 if used in a
condition. However, gcc still bugs about that, so I came up with
another way how to fix that.
Using static inline functions in the header won't collide with anything,
it fixes the bug and does one thing that the macro didn't do. It checks
whenther passed variables are pointers of compatible type. It has only
one downside, and that is that we need to either a) define it with
ATTRIBUTE_UNUSED, which needs an exception in cfg.mk or b) do something
like ignore_value(variable); in the function body. I went with the
first variant.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
We want all threads to be set as workers or to have a job assigned to
them, which can easily be achieved in virThreadCreate wrapper to
pthread_create. Let's make sure we always use the wrapper.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
So far it's just a structure which happens to have 'Obj' in its
name, but otherwise it not related to virObject at all. No
reference counting, not virObjectLock(), nothing.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Well, one day this will be self-locking object, but not today.
But lets prepare the code for that! Moreover,
virNetworkObjListFree() is no longer needed, so turn it into
virNetworkObjListDispose().
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Some code paths have special logic depending on the page size
reported by sysconf, which in turn affects the test results.
We must mock this so tests always have a consistent page size.
Per-cpu stats are only shown for present CPUs in the cgroups,
but we were only parsing the largest CPU number from
/sys/devices/system/cpu/present and looking for stats even for
non-present CPUs.
This resulted in:
internal error: cpuacct parse error
Introduce a Xen xl parser
This parser allows for users to convert the new xl disk format and
spice graphics config to libvirt xml format and vice versa. Regarding
the spice graphics config, the code is pretty much straight forward.
For the disk {formating, parsing}, this parser takes care of the new
xl format which include positional parameters and key/value parameters.
In xl format disk config a <diskspec> consists of parameters separated by
commas. If the parameters do not contain an '=' they are automatically
assigned to certain options following the order below
target, format, vdev, access
The above are the only mandatory parameters in the <diskspec> but there
are many more disk config options. These options can be specified as
key=value pairs. This takes care of the rest of the options such as
devtype, backend, backendtype, script, direct-io-safe,
The positional paramters can also be specified in key/value form
for example
/dev/vg/guest-volume,,hda
/dev/vg/guest-volume,raw,hda,rw
format=raw, vdev=hda, access=rw, target=/dev/vg/guest-volume
are interpleted to one config.
In xm format, the above diskspec would be written as
phy:/dev/vg/guest-volume,hda,w
The disk parser is based on the same parser used successfully by
the Xen project for several years now. Ian Jackson authored the
scanner, which is used by this commit with mimimal changes. Only
the PREFIX option is changed, to produce function and file names
more consistent with libvirt's convention.
Signed-off-by: Kiarie Kahurani <davidkiarie4@gmail.com>
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Since virDomainSnapshotFree will call virObjectUnref anyway, let's just use
that directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Since virInterfaceFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Since virNWFilterFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Since virSecretFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Since virStreamFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Since virStoragePoolFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Since virStorageVolFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Since virNodeDeviceFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Since virNetworkFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
Since virDomainFree will call virObjectUnref anyway, let's just use that
directly so as to avoid the possibility that we inadvertently clear out
a pending error message when using the public API.
virReportSystemError is reserved for reporting system errors, calling it
with VIR_ERR_* error codes produces error messages that do not make any
sense, such as
internal error: guest failed to start: Kernel doesn't support user
namespace: Link has been severed
We should prohibit wrong usage with a syntax-check rule.
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
With this change, any patch declared in libvirt.spec with Patch[0-9]* is
automatically applied in %prep. Unlike with the standard %patch[0-9]*,
patches are applied with "git am" to avoid some unexpected results.
However, as a result of this, all patches must be in the right format
for "git am" to be able to apply them; they should ideally be generated
from git using "git format-patch".
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
I noticed this while working on qemuDomainGetBlockInfo. Assigning
a bool value to an int variable compiles fine, but raises red flags
on the maintenance front as it becomes too easy to assign -1 or 2
or any other non-bool value to the same variable.
* cfg.mk (sc_prohibit_int_assign_bool): New rule.
* src/conf/snapshot_conf.c (virDomainSnapshotRedefinePrep): Fix
offenders.
* src/qemu/qemu_driver.c (qemuDomainGetBlockInfo)
(qemuDomainSnapshotCreateXML): Likewise.
* src/test/test_driver.c (testDomainSnapshotAlignDisks):
Likewise.
* src/util/vircgroup.c (virCgroupSupportsCpuBW): Likewise.
* src/util/virpci.c (virPCIDeviceBindToStub): Likewise.
* src/util/virutil.c (virIsCapableVport): Likewise.
* tools/virsh-domain-monitor.c (cmdDomMemStat): Likewise.
* tools/virsh-domain.c (cmdBlockResize, cmdScreenshot)
(cmdInjectNMI, cmdSendKey, cmdSendProcessSignal)
(cmdDetachInterface): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Now that all offenders have been cleaned, turn on a syntax-check
rule to prevent future offenders.
* cfg.mk (sc_prohibit_static_zero_init): New rule.
* src/qemu/qemu_driver.c (qemuDomainBlockJobImpl): Avoid false
positive.
Signed-off-by: Eric Blake <eblake@redhat.com>
The cfg.mk rule for checking preprocessor indentation was
mistakenly missing the libvirt.h.in file due to bad file
extension matching rule. Fix that and the resolve the
incorrect indentation that is identified.
Create a new libvirt-domain.h file to hold the public
API definitions for the virDomain type. This header
file is not self-contained, so applications will not directly
include it. They will continue to #include <libvirt/libvirt.h>
Spawning the pkcheck program every time a permission check is
required is hugely expensive on CPU. The pkcheck program is just
a dumb wrapper for the DBus API, so rewrite the code to use the
DBus API directly. This also simplifies error handling a bit.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Now that hanging brace offenders have been fixed, we can automate
the check, and document our style. Done as a separate commit from
code changes, to make it easier to just backport code changes, if
that is ever needed.
* cfg.mk (sc_curly_braces_style): Catch hanging braces.
* docs/hacking.html.in: Document it.
* HACKING: Regenerate.
Signed-off-by: Eric Blake <eblake@redhat.com>
Done as a separate commit in case earlier cleanups are backported
independently.
* cfg.mk (sc_require_space_before_label): New rule.
Signed-off-by: Eric Blake <eblake@redhat.com>
Even line like this:
int asdf = i - somevar;
was matched by the regex, so this patch adds '=' to the list of
characters that break the regexp.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
src/xenxs contains parsing/formating functions for the various xen
config formats, and is better named src/xenconfig.
Signed-off-by: Jim Fehlig <jfehlig@suse.com>
Commit 5028160 accidentally weakened the strtol prohibitions to
skip ALL files under src/util instead of the former situation of
just protecting util/virsexpr.c; even though NONE of the files
in that directory need any protection.
Shorten some long lines while at it.
* cfg.mk (exclude_file_name_regexp--sc_prohibit_strtol): No need
to exclude all of util.
(exclude_file_name_regexp--sc_prohibit_sprintf): Reduce long line.
(exclude_file_name_regexp--sc_prohibit_raw_allocation): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
There's this question on the list that is asked over and over again.
How do I get {cpu, memory, ...} usage in percentage? Or its modified
version: How do I plot nice graphs like virt-manager does?
It would be nice if we have an example to inspire people. And that's
what domtop should do. Yes, it could be written in different ways, but
I've chosen this one as I think it show explicitly what users need to
implement in order to imitate virt-manager's graphing.
Note: The usage is displayed from host perspective. That is, how much
host CPUs the domain is using. But it should be fairly simple to
switch do just guest CPU usage if needed.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
There's no need to use it since we have this shiny functions
that even checks for conversion and overflow errors.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The virNodeParseSocket() function tries to get socked ID from
'topology/physical_package_id' file. However, on some architectures
the file contains the -1 constant which makes in turn libvirt think
the info extraction was unsuccessful. If that's the case, we need to
overwrite the obtained integer with zero like we are doing for other
architectures.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Roman Bogorodskiy reported a syntax-check failure when using
FreeBSD; complaining that:
prohibit_empty_first_line
tools/libvirt_win_icon_16x16.ico:1:
tools/libvirt_win_icon_32x32.ico:1:
tools/libvirt_win_icon_48x48.ico:1:
tools/libvirt_win_icon_64x64.ico:1:
maint.mk: Prohibited empty first line
In reality, the first 'line' of that file is NOT empty; but since
it is a binary file, awk is not required to handle it gracefully.
The simplest solution is to exempt all image files from syntax
checks in the first place - after all, we only store them in git
because they are inconvenient to regenerate, but they are not our
preferred format for making modifications, and syntax check should
only cover files that we are likely to modify.
* cfg.mk (VC_LIST_ALWAYS_EXCLUDE_REGEX): Exempt images.
(exclude_file_name_regexp--sc_prohibit_empty_lines_at_EOF): Simplify.
(exclude_file_name_regexp--sc_trailing_blank): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
I accidentally typed 'make' in the srcdir of a VPATH build, and
was surprised to see this:
$ make
/bin/sh: s/^[ +-]//;s/ .*//: No such file or directory
INFO: gnulib update required; running ./autogen.sh first
make: -n: Command not found
./autogen.sh
I am going to run ./configure with no arguments - if you wish
to pass any to it, please specify them on the ./autogen.sh command line.
running bootstrap...
./bootstrap: Bootstrapping from checked-out libvirt sources...
./bootstrap: getting gnulib files...
Oops - we're trying to execute some fairly bogus command names,
and then trying to configure in-tree (which breaks all existing
VPATH builds, since automake refuses to do a VPATH build if it
detects an in-tree configure). The third line (executing "-n")
is fixed by updating to the latest gnulib; the rest of the problem
is fixed by copying the same filtering in our cfg.mk as what
gnulib just added, so that we avoid any $(shell) invocations which
in turn depend on variables that are only populated by a working
Makefile. With that in place, we are back to the much nicer:
$ make
There seems to be no Makefile in this directory.
You must run ./configure before running 'make'.
make: *** [abort-due-to-no-makefile] Error 1
Additionally, although harder to see - there was a trailing space in
the message warning us that autogen would run an in-tree configure.
* .gnulib: Update to latest, in part for maint.mk improvements.
* cfg.mk (_update_required): Don't check for update in
unconfigured directory.
* autogen.sh (no_git): Drop trailing space.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reusing the maint.mk code allows for a more efficient syntax check
(fewer grep processes), and a more compact representation of what
we are really checking for in commit 1919e35.
* cfg.mk (sc_require_locale_h): Use maint.mk loop instead of
rolling our own.
Signed-off-by: Eric Blake <eblake@redhat.com>
In the past we had some issues where setlocale() was called without
corresponding include of locale.h. While on some systems this may
work, on others the compilation failed. We should have a syntax-check
rule for that to prevent this from happening again.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
My future work will modify the metadata crawler function to use the
storage driver file APIs to access the files instead of accessing them
directly so that we will be able to request the metadata for remote
files too. To avoid linking the storage driver to every helper file
using the utils code, the backing chain traversal function needs to be
moved to the storage driver source.
Additionally the virt-aa-helper and virstoragetest programs need to be
linked with the storage driver as a result of this change.
Now that all clients have been adjusted, ensure that no future
misuse of readdir is introduced into the code base.
* cfg.mk (sc_prohibit_readdir): New rule.
* src/util/virfile.c (virDirRead): Exempt the wrapper.
Signed-off-by: Eric Blake <eblake@redhat.com>
In 'make syntax-check', we have a rule that prevents layering
violations between the various files in src. However, we
forgot to treat conf/ and the more recently-added access/ as
lower-level directories, and were not detecting cases where
they might have used a driver file. Also, it's not nice that
qemu can use storage/ but none of the other drivers could do so.
* cfg.mk (sc_prohibit_cross_inclusion): Tighten rules for conf/
and access/, let all other drivers use storage/.
Signed-off-by: Eric Blake <eblake@redhat.com>
Using any of these chars [:*?"<>|] in a filename is forbidden on
Windows and breaks git operations on Windows as git is not able
to create those files/directories on clone or pull.
Because some of them can be used in UNIX filenames they tend to
creep into filenames; especially : in PCI/SCSI device names that
are used as filenames in test cases.
Although not explicitly requested, we are using K&R (or Kernel)
indentation for curly braces around functions in HACKING file and most
of the code. Using grep -P, this patch add the syntax-check rule for
it (while skipping all the false positives with foreach constructs).
Signed-off-by: Martin 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: Daniel P. Berrange <berrange@redhat.com>
Addition of vshConnect() makes virConnectOpen() functions obsolete in
virsh. Thus all virsh-*.[ch] files should be left only with
vshConnect() in the case of need.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
This rule wouldn't be able to find any case of a hardcoded indent that
was in the middle of a string, but then virBuffer doesn't add
indentation in the middle of a string either.
The previous OOM testing support would re-run the entire "main"
method each iteration, failing a different malloc each time.
When a test suite has 'n' allocations, the number of repeats
requires is (n * (n + 1) ) / 2. This gets very large, very
quickly.
This new OOM testing support instead integrates at the
virtTestRun level, so each individual test case gets repeated,
instead of the entire test suite. This means the values of
'n' are orders of magnitude smaller.
The simple usage is
$ VIR_TEST_OOM=1 ./qemuxml2argvtest
...
29) QEMU XML-2-ARGV clock-utc ... OK
Test OOM for nalloc=36 .................................... OK
30) QEMU XML-2-ARGV clock-localtime ... OK
Test OOM for nalloc=36 .................................... OK
31) QEMU XML-2-ARGV clock-france ... OK
Test OOM for nalloc=38 ...................................... OK
...
the second lines reports how many mallocs have to be failed, and thus
how many repeats of the test will be run.
If it crashes, then running under valgrind will often show the problem
$ VIR_TEST_OOM=1 ../run valgrind ./qemuxml2argvtest
When debugging problems it is also helpful to select an individual
test case
$ VIR_TEST_RANGE=30 VIR_TEST_OOM=1 ../run valgrind ./qemuxml2argvtest
When things get really tricky, it is possible to request that just
specific allocs are failed. eg to fail allocs 5 -> 12, use
$ VIR_TEST_RANGE=30 VIR_TEST_OOM=1:5-12 ../run valgrind ./qemuxml2argvtest
In the worse case, you might want to know the stack trace of the
alloc which was failed then VIR_TEST_OOM_TRACE can be set. If it
is set to 1 then it will only print if it thinks a mistake happened.
This is often not reliable, so setting it to 2 will make it print
the stack trace for every alloc that is failed.
$ VIR_TEST_OOM_TRACE=2 VIR_TEST_RANGE=30 VIR_TEST_OOM=1:5-5 ../run valgrind ./qemuxml2argvtest
30) QEMU XML-2-ARGV clock-localtime ... OK
Test OOM for nalloc=36 !virAllocN
/home/berrange/src/virt/libvirt/src/util/viralloc.c:180
virHashCreateFull
/home/berrange/src/virt/libvirt/src/util/virhash.c:144
virDomainDefParseXML
/home/berrange/src/virt/libvirt/src/conf/domain_conf.c:11745
virDomainDefParseNode
/home/berrange/src/virt/libvirt/src/conf/domain_conf.c:12646
virDomainDefParse
/home/berrange/src/virt/libvirt/src/conf/domain_conf.c:12590
testCompareXMLToArgvFiles
/home/berrange/src/virt/libvirt/tests/qemuxml2argvtest.c:106
virtTestRun
/home/berrange/src/virt/libvirt/tests/testutils.c:250
mymain
/home/berrange/src/virt/libvirt/tests/qemuxml2argvtest.c:418 (discriminator 2)
virtTestMain
/home/berrange/src/virt/libvirt/tests/testutils.c:750
??
??:0
_start
??:?
FAILED
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Use the new storage driver APIs to delete snapshot backing files in case
of failure instead of directly relying on "unlink". This will help us in
the future when we will be adding network based storage without local
representation in the host.
Introduce Wireshark dissector plugin which adds support to Wireshark
for dissecting libvirt RPC protocol.
Added following files to build Wireshark dissector from libvirt source
tree.
* tools/wireshark/*: Source tree of Wireshark dissector plugin.
Added followings to configure.ac or Makefile.am.
configure.ac
* --with-wireshark-dissector: Enable support for building Wireshark
dissector.
* --with-ws-plugindir: Specify wireshark plugin directory that dissector
will installed.
* Added tools/wireshark/{Makefile,src/Makefile} to AC_CONFIG_FILES.
Makefile.am
* Added tools/wireshark/ to SUBDIR.
Finish the cleanup of libvirt.c; all uses of virLib*Error have
now been converted to more canonical conventions.
* src/libvirt.c: Use virReportError in remaining errors.
(virLibConnError, virLibDomainError): Delete unused macros.
* cfg.mk (msg_gen_function): Drop unused names.
Signed-off-by: Eric Blake <eblake@redhat.com>
This partially reverts 5eb4b04211 and 62774afb6b.
Rewrite the domsuspend example from scratch. This time do it right.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The domain events demo program isn't really tied to domain
events anymore, so rename it to object events.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Kill the use of atoi() and introduce syntax check to forbid it and it's
friends (atol, atoll, atof, atoq).
Also fix a typo in variable name holding the cylinders count of a disk
pool (apparently unused).
examples/domsuspend/suspend.c will need a larger scale refactor as the
whole example file is broken thus it will be exempted from the syntax
check for now.
The python binding now lives in
http://libvirt.org/git/?p=libvirt-python.git
that repo also provides an RPM which is upgrade compatible
with the old libvirt-python sub-RPM.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
This addition, however, requires some refactoring to be done. First of
all, to match the best practice we should detach the device prior
resetting it. That's why testVirPCIDeviceDetach is detaching all devices
within 0000:00:01.0 and 0000:00:03.0 range. Then, the brand new test
will reset the 0000:00:02.0 device, so the last testVirPCIDeviceReattach
can reattach all the devices back.
In order to perform a PCI device reset, the dummy config file is not
sufficient anymore and must be replaced with real PCI config (binary
mess). Such config files are to be stored under tests/virpcitestdata/
and ought to have '.config' suffix.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This commit introduces yet another test under virpcitest:
virPCIDeviceDetach. However, in order to be able to do this, the
virpcimock needs to be extended to model the kernel behavior on PCI
device binding and unbinding (create 'driver' symlinks under the device
tree, check for device ID in driver's ID table, etc.)
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
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>
To make it easier to forbid future attempts at a confusing typedef
name ending in Ptr that isn't actually a pointer, insist that we
follow our preferred style of 'typedef foo *fooPtr'.
* cfg.mk (sc_forbid_const_pointer_typedef): Enforce consistent
style, to prevent issue fixed in previous storage patch.
* src/conf/capabilities.h (virCapsPtr): Fix offender.
* src/security/security_stack.c (virSecurityStackItemPtr):
Likewise.
* tests/qemucapabilitiestest.c (testQemuDataPtr): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
On RHEL 5, make syntax-check was failing because even strings like
'int isTempChain' matched the 'int i' rule. To be honest, I haven't
found the root cause, but the change added makes it work as expected
and keeps the proper behavior on newer systems as well.
The use of getenv is typically insecure, and we want people
to use our wrappers, to force them to think about setuid
needs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
'const fooPtr' is the same as 'foo * const' (the pointer won't
change, but it's contents can). But in general, if an interface
is trying to be const-correct, it should be using 'const foo *'
(the pointer is to data that can't be changed).
Now that the code base has been cleaned, enforce it with a syntax
checker.
* cfg.mk (sc_forbid_const_pointer_typedef): New rule.
Signed-off-by: Eric Blake <eblake@redhat.com>
Start a test case for the virNetServerClient object, which
initially checks the creation of a virIdentityPtr object.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
We have been adding new .x files without keeping the list of
*-structs files up-to-date. This adds the support for the
recent additions.
In the process of testing this, I also noticed that Fedora 19's
use of dwarves-1.10 (providing pdwtags version 1.9) was producing
a single line on stderr but still giving enough useful info on
stdout that we could check structs; the real goal of checking
stderr separately from stdout was to avoid the bug in dwarves-1.9
where stdout was empty (see bug http://bugzilla.redhat.com/772358).
* src/Makefile.am (struct_prefix, PROTOCOL_STRUCTS): Add missing
struct tests.
(PDWTAGS): Work with Fedora 19 pdwtags.
(lxc_monitor_protocol-struct, lock_protocol-struct): New rules.
* src/lxc_monitor_protocol-structs: New file.
* src/lock_protocol-structs): Likewise.
* cfg.mk (generated_files): Enlarge list.
Signed-off-by: Eric Blake <eblake@redhat.com>
Automake has builtin support to prevent botched conditional nesting,
but only if you use:
if FOO
else !FOO
endif !FOO
An example error message when using the wrong name:
daemon/Makefile.am:378: error: else reminder (LIBVIRT_INIT_SCRIPT_SYSTEMD_TRUE) incompatible with current conditional: LIBVIRT_INIT_SCRIPT_SYSTEMD_FALSE
daemon/Makefile.am:381: error: endif reminder (LIBVIRT_INIT_SCRIPT_SYSTEMD_TRUE) incompatible with current conditional: LIBVIRT_INIT_SCRIPT_SYSTEMD_FALSE
As our makefiles tend to have quite a bit of nested conditionals,
it's better to take advantage of the benefits of the build system
double-checking that our conditionals are well-nested, but that
requires a syntax check to enforce our usage style.
Alas, unlike C preprocessor and spec files, we can't use indentation
to make it easier to see how deeply nesting goes.
* cfg.mk (sc_makefile_conditionals): New rule.
* daemon/Makefile.am: Enforce the style.
* gnulib/tests/Makefile.am: Likewise.
* python/Makefile.am: Likewise.
* src/Makefile.am: Likewise.
* tests/Makefile.am: Likewise.
* tools/Makefile.am: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
The use of <> is a security issue for RPC parameters, since a
malicious client can set a huge array length causing arbitrary
memory allocation in the daemon.
It is also a robustness issue for RPC return values, because if
the stream is corrupted, it can cause the client to also allocate
arbitrary memory.
Use a syntax-check rule to prohibit any use of <>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The virnettlscontexttest.c tests both virNetTLSContext
and virNetTLSSession functionality. Split into two
separate tests, to make the code size more manageable
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit 3d0e3c1 reintroduced a problem previously squelched in
commit 7e5aa78. Add a syntax check this time around.
util/virutil.c: In function 'virGetGroupList':
util/virutil.c:1015: error: 'for' loop initial declaration used outside C99 mode
* cfg.mk (sc_prohibit_loop_var_decl): New rule.
* src/util/virutil.c (virGetGroupList): Fix offender.
Signed-off-by: Eric Blake <eblake@redhat.com>
Makefiles are another easy file to enforce line limits.
Mostly straightforward; interesting tricks worth noting:
src/Makefile.am: $(confdir) was already defined, use it in more places
tests/Makefile.am: path_add and VG required some interesting compression
* cfg.mk (sc_prohibit_long_lines): Add another test.
* Makefile.am: Fix offenders.
* daemon/Makefile.am: Likewise.
* docs/Makefile.am: Likewise.
* python/Makefile.am: Likewise.
* src/Makefile.am: Likewise.
* tests/Makefile.am: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Long lines are harder to read and harder to diff; in fact, if lines get
too long (> 1000 bytes), it starts causing issues where git send-email
refuses to send patches for the file. I've cleaned up the tests
directory in the past (see commits bd6c46f, 3b750d1), but new long
lines have been introduced in the meantime.
Why 90 instead of 80? Because there were too many tests on the fringe
edge, and I didn't want to edit that many files.
Add a syntax check to prevent future long lines.
* cfg.mk (sc_prohibit_long_lines): New rule.
* tests/qemuxml2argvdata/qemuxml2argv-*.args: Split lines of any
file with content longer than 90 columns.
* tests/storagevolxml2argvdata/*.argv: Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Add two syntax-check rules
- sc_prohibit_int_ijk - block use of 'int' as a data type
for any variables named 'i', 'j', 'k'
- sc_prohibit_int_iijjkk - block use of 'ii', 'jj', 'kk'
for any variable names
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.
Based on a report by Chandrashekar Shastri, at
https://bugzilla.redhat.com/show_bug.cgi?id=979360
On systems where git cannot access the outside world, a developer
can instead arrange to get a copy of gnulib at the right commit
via side channels (such as NFS share drives), set GNULIB_SRCDIR,
then use ./autogen.sh --no-git. In this setup, we will now
avoid direct use of git. Of course, this means no automatic
gnulib updates when libvirt.git updates its submodule, but it
is expected that any developer in such a situation is already
prepared to deal with the fallout.
* .gnulib: Update to latest, for bootstrap.
* bootstrap: Synchronize from gnulib.
* autogen.sh (no_git): Avoid git when requested.
* cfg.mk (_update_required): Skip automatic rerun of bootstrap if
we can't use git.
* docs/compiling.html.in: Document this setup.
* docs/hacking.html.in: Mention this.
* HACKING: Regenerate.
Signed-off-by: Eric Blake <eblake@redhat.com>
Osier Yang pointed out that I introduced a syntax error in my
syntax check (I really shouldn't make last-minute changes without
testing them....).
/bin/sh: -c: line 2: syntax error near unexpected token `;'
/bin/sh: -c: line 2: ` { echo 'maint.mk: incorrect whitespace, see HACKING for rules' 2>&; \'
make: *** [bracket-spacing-check] Error 1
* cfg.mk (bracket-spacing-check): Fix copy-and-paste error.
Signed-off-by: Eric Blake <eblake@redhat.com>
To ensure we don't regress and cause the need for further
cleanups, add a 'make syntax-check' rule that ensures new
files have proper copyright contents.
* cfg.mk (sc_copyright_address): Rename...
(sc_copyright_usage): ...and enhance.
Signed-off-by: Eric Blake <eblake@redhat.com>
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>
Use of the select() system call is inherantly dangerous since
applications will hit a buffer overrun if any FD number exceeds
the size of the select set size (typically 1024). Replace the
two uses of select() with poll() and use cfg.mk to ban any
future use of select().
NB: This changes the phyp driver so that it uses an infinite
timeout, instead of busy-waiting for 1ms at a time.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
These all existed before virfile.c was created, and for some reason
weren't moved.
This is mostly straightfoward, although the syntax rule prohibiting
write() had to be changed to have an exception for virfile.c instead
of virutil.c.
This movement pointed out that there is a function called
virBuildPath(), and another almost identical function called
virFileBuildPath(). They really should be a single function, which
I'll take care of as soon as I figure out what the arglist should look
like.
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.
POSIX says that both basename() and dirname() may return static
storage (aka they need not be thread-safe); and that they may but
not must modify their input argument. Furthermore, <libgen.h>
is not available on all platforms. For these reasons, you should
never use these functions in a multi-threaded library.
Gnulib instead recommends a way to avoid the portability nightmare:
gnulib's "dirname.h" provides useful thread-safe counterparts. The
obvious dir_name() and base_name() are GPL (because they malloc(),
but call exit() on failure) so we can't use them; but the LGPL
variants mdir_name() (malloc's or returns NULL) and last_component
(always points into the incoming string without modifying it,
differing from basename semantics only on corner cases like the
empty string that we shouldn't be hitting in the first place) are
already in use in libvirt. This finishes the swap over to the safe
functions.
* cfg.mk (sc_prohibit_libgen): New rule.
* src/util/vircgroup.c: Fix offenders.
* src/parallels/parallels_storage.c (parallelsPoolAddByDomain):
Likewise.
* src/parallels/parallels_network.c (parallelsGetBridgedNetInfo):
Likewise.
* src/node_device/node_device_udev.c (udevProcessSCSIHost)
(udevProcessSCSIDevice): Likewise.
* src/storage/storage_backend_disk.c
(virStorageBackendDiskDeleteVol): Likewise.
* src/util/virpci.c (virPCIGetDeviceAddressFromSysfsLink):
Likewise.
* src/util/virstoragefile.h (_virStorageFileMetadata): Avoid false
positive.
Signed-off-by: Eric Blake <eblake@redhat.com>
With this patch, include public headers in "" form is only allowed
for "internal.h". And only the external tools (examples|tools|python
|include/libvirt) can include the public headers in <> form.
Directories python/tools/examples should include them in <> form,
though this patch allows "" form in these directories by excluding
them, a later patch will do the cleanup.
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>
We've already scrubbed for comparisons of 'uid_t == -1' (which fail
on platforms where uid_t is a u16), but another one snuck in.
* src/util/virutil.c (virSetUIDGIDWithCaps): Correct uid comparison.
* cfg.mk (sc_prohibit_risky_id_promotion): New rule.
testutils.c likes to print summaries after a test completes,
including if it failed. But if the test outright exit()s,
this summary is skipped. Enforce that we return instead of exit.
* cfg.mk (sc_prohibit_exit_in_tests): New syntax check.
* tests/commandhelper.c (main): Fix offenders.
* tests/qemumonitorjsontest.c (mymain): Likewise.
* tests/seclabeltest.c (main): Likewise.
* tests/securityselinuxlabeltest.c (mymain): Likewise.
* tests/securityselinuxtest.c (mymain): Likewise.
* tests/testutils.h (VIRT_TEST_MAIN_PRELOAD): Likewise.
* tests/testutils.c (virtTestMain): Likewise.
(virtTestCaptureProgramOutput): Use symbolic name.
hacking: Add some text around the running of Valgrind along with example
output for "real" vs. "false positives".
cfg.mk: Add hacking.in.html to sc_prohibit_raw_allocation
Adjust the macros to free memory allocated during various calls to
perform the check if parameter is NULL prior to really freeing and to
set the pointer to NULL after done freeing.
Nested conditionals are hard to read if they are not indented.
We can't add arbitrary whitespace to everything in spec files,
but we CAN add spaces before %if and %define. Use this trick,
plus a fancy sed script that rewrites a spec file into a C
file, so we can use cppi to keep our spec file nice.
For reference, the sed script converts code like:
|# RHEL-5 builds are client-only for s390, ppc
|%if 0%{?rhel} == 5
| %ifnarch %{ix86} x86_64 ia64
| %define client_only 1
| %endif
|%endif
into the following for cppi:
|// # RHEL-5 builds are client-only for s390, ppc
|#if a // 0%{?rhel} == 5
|# if a // %{ix86} x86_64 ia64
|# define client_only 1
|# endif
|#endif
and errors from 'make syntax-check' look like:
spec_indentation
cppi: mingw-libvirt.spec.in: line 130: not properly indented
maint.mk: incorrect preprocessor indentation
* libvirt.spec.in: Add some indentation to make it easier to follow
various conditionals.
* mingw-libvirt-spec.in: Likewise.
* cfg.mk (sc_spec_indentation): New syntax check to enforce it.
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>
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>
Most checks for libraries take the same format
* --with-libFOO=yes|no|check|/some/path argument
* check for a function NNN in libFOO.so
* check for a header file DDD/HHH.h
* Define a WITH_FOO config.h symbol
* Define a WITH_FOO make conditional
* Substitute FOO_CFLAGS and FOO_LIBS make variables
* Print CFLAGS & LIBS summary at the end
Doing all this correctly is rather difficult, typically
done by copy+paste of a previous usage. Further small
improvements people make are not applied to all previous
usages.
Improve this by creating some helper macros to apply
good practice. First, to perform the actual checks:
LIBVIRT_CHECK_LIB([SELINUX], [selinux],
[getfilecon], [selinux/selinux.h])
This checks for 'getfilecon' in -lselinux, and the
existence of 'selinux/selinux.h' header file. If successful
it sets SELINUX_CFLAGS and SELINUX_LIBS. The WITH_SELINUX
config.h macro and WITH_SELINUX make conditional are also
defined.
In some cases we need to check two variants of the same
library
LIBVIRT_CHECK_LIB_ALT([SASL], [sasl2],
[sasl_client_init], [sasl/sasl.h],
[SASL1], [sasl],
[sasl_client_init], [sasl/sasl.h])
This checks for sasl_client_init in libsasl2, and if that
is not found, checks sasl_client_init in libsasl. If the
first check succeeds WITH_SASL is set, while if the second
check succeeds *both* WITH_SASL and WITH_SASL1 are set.
If the library supports pkg-config, then another variant
is available
LIBVIRT_CHECK_PKG([AVAHI], [avahi-client], [0.6.0])
This checks for avahi-client >= 0.6.0 via pkg-config
and sets WITH_AVAHI if found.
Finally to print a summary of CFLAGS & LIBs found (if any):
LIBVIRT_RESULT_LIB([SELINUX])
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Test cases for virSysinfoRead. Initially, there are tests for
x86 (DMI based) and s390 (/proc/... based).
In lack of PPC data, I have stubbed out the test for it, but it
can be added with a minimal effort.
Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
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>
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>
I noticed when writing the backend functions for virNetworkUpdate that
I was repeating the same sequence of memmove, VIR_REALLOC, nXXX-- (and
messed up the args to memmove at least once), and had seen the same
sequence in a lot of other places, so I decided to write a few
utility functions/macros - see the .h file for full documentation.
The intent is to reduce the number of lines of code, but more
importantly to eliminate the need to check the element size and
element count arithmetic every time we need to do this (I *always*
make at least one mistake.)
VIR_INSERT_ELEMENT: insert one element at an arbitrary index within an
array of objects. The size of each object is determined
automatically by the macro using sizeof(*array). The new element's
contents are copied into the inserted space, then the original copy
of contents are 0'ed out (if everything else was
successful). Compile-time assignment and size compatibility between
the array and the new element is guaranteed (see explanation below
[*])
VIR_INSERT_ELEMENT_COPY: identical to VIR_INSERT_ELEMENT, except that
the original contents of newelem are not cleared to 0 (i.e. a copy
is made).
VIR_APPEND_ELEMENT: This is just a special case of VIR_INSERT_ELEMENT
that "inserts" one past the current last element.
VIR_APPEND_ELEMENT_COPY: identical to VIR_APPEND_ELEMENT, except that
the original contents of newelem are not cleared to 0 (i.e. a copy
is made).
VIR_DELETE_ELEMENT: delete one element at an arbitrary index within an
array of objects. It's assumed that the element being deleted is
already saved elsewhere (or cleared, if that's what is appropriate).
All five of these macros have an _INPLACE variant, which skips the
memory re-allocation of the array, assuming that the caller has
already done it (when inserting) or will do it later (when deleting).
Note that VIR_DELETE_ELEMENT* can return a failure, but only if an
invalid index is given (index + amount to delete is > current array
size), so in most cases you can safely ignore the return (that's why
the helper function virDeleteElementsN isn't declared with
ATTRIBUTE_RETURN_CHECK). A warning is logged if this ever happens,
since it is surely a coding error.
[*] One initial problem with the INSERT and APPEND macros was that,
due to both the array pointer and newelem pointer being cast to void*
when passing to virInsertElementsN(), any chance of type-checking was
lost. If we were going to move in newelem with a memmove anyway, we
would be no worse off for this. However, most current open-coded
insert/append operations use direct struct assignment to move the new
element into place (or just populate the new element directly) - thus
use of the new macros would open a possibility for new usage errors
that didn't exist before (e.g. accidentally sending &newelemptr rather
than newelemptr - I actually did this quite a lot in my test
conversions of existing code).
But thanks to Eric Blake's clever thinking, I was able to modify the
INSERT and APPEND macros so that they *do* check for both assignment
and size compatibility of *ptr (an element in the array) and newelem
(the element being copied into the new position of the array). This is
done via clever use of the C89-guaranteed fact that the sizeof()
operator must have *no* side effects (so an assignment inside sizeof()
is checked for validity, but not actually evaluated), and the fact
that virInsertElementsN has a "# of new elements" argument that we
want to always be 1.
Commit 71d1256 tried to fix a problem where rebasing an old
branch on top of newer libvirt.git resulted in automake failing
because of a missing AUTHORS file. However, while the fix
worked for an incremental 'make', it did not work for someone
that directly reran './autogen.sh'. Reported by Laine Stump.
* autogen.sh (autoreconf): Check for same conditions as cfg.mk.
* cfg.mk (_update_required): Add comments.
Ever since commit 7b21981c started generating AUTHORS, we now have
the situation that if you flip between two branches in the same
git repository that cross that commit boundary, then 'make' will
fail due to automake complaining about AUTHORS not existing. The
simplest solution is to realize that if AUTHORS does not exist,
then we flipped branches so we will need to rerun bootstrap
anyways; and rerunning bootstrap ensures AUTHORS will exist in time.
* cfg.mk (_update_required): Also depend on AUTHORS.
