Re: [libvirt] [PATCH] Make QEMU text monitor parsing more robust

On Tue, Dec 08, 2009 at 06:08:04PM +0000, Daniel P. Berrange wrote: > The QEMU 0.10.0 release (and possibly other 0.10.x) has a bug where > it sometimes/often forgets to display the initial monitor greeting > line, soley printing a (qemu). This in turn confuses the text > console parsing because it has a '(qemu)' it is not expecting. The > confusion results in a negative malloc. Bad things follow. > > This re-writes the text console handling to be more robust. The key > idea is that it should only look for a (qemu), once it has seen the > original command echo'd back. This ensures it'll skip the bogus stray > (qemu) with broken QEMUs. > > * src/qemu/qemu_monitor.c: Add some (disabled) debug code > * src/qemu/qemu_monitor_text.c: Re-write way command replies > are detected > --- > src/qemu/qemu_monitor.c | 28 +++++++++++ > src/qemu/qemu_monitor_text.c | 102 +++++++++++++++++++++++++++-------------- > 2 files changed, 95 insertions(+), 35 deletions(-) > > diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c > index abb763c..103cf28 100644 > --- a/src/qemu/qemu_monitor.c > +++ b/src/qemu/qemu_monitor.c > @@ -39,6 +39,8 @@ > > #define VIR_FROM_THIS VIR_FROM_QEMU > > +#define QEMU_DEBUG_RAW_IO 0 > + > struct _qemuMonitor { > virMutex lock; > virCond notify; > @@ -163,6 +165,24 @@ char *qemuMonitorEscapeShell(const char *in) > } > > > +#if QEMU_DEBUG_RAW_IO > +#include <c-ctype.h> > +static char * qemuMonitorEscapeNonPrintable(const char *text) > +{ > + int i; > + virBuffer buf = VIR_BUFFER_INITIALIZER; > + for (i = 0 ; text[i] != '\0' ; i++) { > + if (c_isprint(text[i]) || Hum I just hope c_isprint behaviour doesn't depend on the user locale, otherwise I would just replace it with an explicit value test on the ASCII range, not a big deal since it's just for debug though ...