The way we were casting small (<32bit) integers was broken
on big endian hosts, causing stack smashing. This was detected
in the test suite either by test failures due to incorrect
results, or by libc/gcc abort'ing with its stack canary
triggered.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
since sizeof(int) != sizeof(long long) on 32bit archs.
This unbreaks virdbustest which otherwise fails like:
(gdb) bt
#0 __strlen_sse2_bsf () at ../sysdeps/i386/i686/multiarch/strlen-sse2-bsf.S:50
#1 0x405907d2 in ?? () from /lib/i386-linux-gnu/libdbus-1.so.3
#2 0x4057c140 in ?? () from /lib/i386-linux-gnu/libdbus-1.so.3
#3 0x4057e7ec in dbus_message_iter_append_basic () from /lib/i386-linux-gnu/libdbus-1.so.3
#4 0x400742ec in virDBusMessageIterEncode (args=0xbfd4b8f0 "k\321\004\b.", types=0x804d260 "",
rootiter=0xbfd4b844) at util/virdbus.c:560
#5 virDBusMessageEncodeArgs (msg=msg@entry=0x893c278, types=types@entry=0x804d25c "sais",
args=args@entry=0xbfd4b8d8 "r\320\004\b\003") at util/virdbus.c:921
#6 0x40075917 in virDBusMessageEncode (msg=0x893c278, types=0x804d25c "sais") at util/virdbus.c:959
#7 0x0804a4a1 in testMessageArray (args=0x0) at virdbustest.c:195
#8 0x0804c404 in virtTestRun (title=title@entry=0x804cfcb "Test message array ",
nloops=nloops@entry=1, body=body@entry=0x804a3f0 <testMessageArray>, data=data@entry=0x0)
at testutils.c:168
#9 0x08049346 in mymain () at virdbustest.c:384
#10 0x0804cb2e in virtTestMain (argc=argc@entry=1, argv=argv@entry=0xbfd4bb24,
func=func@entry=0x80492c0 <mymain>) at testutils.c:764
#11 0x080491af in main (argc=1, argv=0xbfd4bb24) at virdbustest.c:393
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>
