Previously I noticed that bfan used this command without any error:
><fs> hivex-open /WINDOWS/system32/config/software write:ture
^^^^^^^^^^
This was because the code allowed any string to be evaluated as a
boolean.
The new code is stricter. It allows the following strings only case
insensitive (everything else is an error):
1
true
t
yes
y
on
0
false
f
no
n
off
Not to be confused with the libxml2 macro 'BAD_CAST' which converts
from 'signed char *' to 'unsigned char *'.
The 'bad_cast' function was defined and used all over the place as a
replacement for a '(char *)' cast. I think it is better to make these
casts explicit, instead of hiding them in an obscure function.
This commit rearranges the internal header files.
"src/guestfs-internal.h" is just for the library, as before.
"src/guestfs-internal-frontend.h" is for use by all library, bindings,
tools C code, but NOT the daemon.
"src/guestfs-internal-all.h" is for use by all C code including the
daemon.
This is just code motion, but it has some important consequences:
(1) We can use the CLEANUP_* macros in bindings and tools code.
(2) We can get rid of TMP_TEMPLATE_ON_STACK.
(3) We will (in future) be able to stop bindings and tools code from
using the safe_* allocation functions (which are NOT safe to use
outside the library alone).
qemu-wrapper isn't regenerated if QEMUDIR is changed, so just
delete it and force regeneration.
Additionally we can drop the silent binary check, since
check-with-upstream-qemu-1 already does a similar test with --version
that will actually report an error to the user.
Certain functions are intended to be internal only, but we currently
export them anyway. This change moves them into a separate section of
guestfs.h protected by a GUESTFS_PRIVATE variable. This change also
enables private structs, but doesn't implement any.
This change only affects the C api. Language bindings aren't affected,
but probably should be in the future.
Without this change all the tests in the haskell bindings are rebuilt
every time. The primary motivation for this change is to fix this.
The fix for the above also allows parallel builds to be re-enabled.
Use the macro like this to create temporary variables which are
automatically cleaned up when the scope is exited:
{
CLEANUP_FREE char *foo = safe_strdup (bar);
...
// no need to call free (foo)!
}
The following code is also valid. The initialization of foo as 'NULL'
prevents any chance of free being called on an uninitialized pointer.
It may not be required in all cases.
{
CLEANUP_FREE char *foo = NULL;
...
foo = safe_malloc (100);
...
// no need to call free (foo)!
}
This is also valid:
{
CLEANUP_FREE char *foo = ..., *bar = ...;
...
// no need to call free (foo) or free (bar)!
}
The CLEANUP_FREE_STRING_LIST macro calls guestfs___free_string_list
on its argument. The argument may be NULL.
The CLEANUP_HASH_FREE macro calls hash_free on its argument. The
argument may be NULL.
Important implementation note:
------------------------------
On GCC and LLVM, this is implemented using __attribute__((cleanup(...))).
There is no known way to implement this macro on other C compilers, so
this construct will cause a resource leak.
Important note about close/fclose:
----------------------------------
We did NOT implement 'CLEANUP_CLOSE' or 'CLEANUP_FCLOSE' macros. The
reason is that I am not convinced that these can be used safely. It
would be OK to use these to collect file handles along failure paths,
but you would still want a regular call to 'close'/'fclose' since you
must test for errors, and so you end up having to do:
if (close (fd) == -1) {
// failure case
// avoid double-close in cleanup handler:
fd = -1;
...
}
// avoid double-close in cleanup handler:
fd = -1;
...
This is just code motion, but it allows us to read this flag inside
the 'construct_libvirt_xml_seclabel' function in future (as a possible
way to fix RHBZ#890291).
When debugging is enabled, this produces output like below. This is
useful when diagnosing what URI libguestfs is using.
libguestfs: opening libvirt handle: URI = NULL, auth = virConnectAuthPtrDefault, flags = 0
libguestfs: successfully opened libvirt handle: conn = 0xb05580
guestfs_last_errno (g) == 0 doesn't mean "no error". It means the
errno was not captured. In this case we have to substitute some sort
of errno, so choose EINVAL arbitrarily.
The reasons to do this are twofold:
(a) It's probably a tiny bit faster.
(b) It lets us capture the real errno if the link(2) syscall fails.
The errno is also passed through guestmount, fixing RHBZ#895905:
+ guestmount -a test1.img -m /dev/sda1:/ -m /dev/sda2:/boot /tmp/mnt
+ touch /tmp/mnt/foo
+ cd /tmp/mnt
+ ln foo boot/foo
ln: failed to create hard link ‘boot/foo’ => ‘foo’: Invalid cross-device link
