[libvirt] [PATCH] test_driver: implement virDomainSendProcessSignal

[Erik Skultety]

On Tue, Jun 04, 2019 at 03:17:43PM +0200, Ilias Stamatis wrote:
> Only succeed when @pid_value is 1, since according to the docs this is

Why do we need to restrict ourselves for @pid 1 in the test driver? This
restriction exists in LXC for a reason, but why in test driver?
a) it's only a check with @pid not being actually used
b) each guest OS will have their own limit in /proc/sys/kernel/pid_max for the
max number of PID so restricting it from the top doesn't make sense
c) - at pid is used for process groups, so again, this will be handled within the
guest OS in reality

With the check removed:
Reviewed-by: Erik Skultety <eskultet at redhat.com>

> the minimum requirement for any driver to implement this API.
>
> >From man 2 kill:
> The only signals that can be sent to process ID 1, the init process, are
> those for which init has explicitly installed signal handlers.
>
> Regarding sending SIGTERM and SIGKILL to init, the test driver domains
> pretend to run Linux, and on Linux init/systemd explicitly ignores these
> signals.
>
> Correspondingly, we can assume that no signal handlers are installed for
> any other signal and succeed by doing nothing.
>
> Signed-off-by: Ilias Stamatis <stamatis.iliass at gmail.com>
> ---
>
> Alternatively, we could succeed when @pid_value is any number or belongs
> to a set of specific numbers.
>
>  src/test/test_driver.c | 35 +++++++++++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
>  mode change 100644 => 100755 src/test/test_driver.c
>
> diff --git a/src/test/test_driver.c b/src/test/test_driver.c
> old mode 100644
> new mode 100755
> index cae2521b21..490a605a77
> --- a/src/test/test_driver.c
> +++ b/src/test/test_driver.c
> @@ -2825,6 +2825,40 @@ static int testDomainSetMetadata(virDomainPtr dom,
>      return ret;
>  }
>
> +static int
> +testDomainSendProcessSignal(virDomainPtr dom,
> +                            long long pid_value,
> +                            unsigned int signum,
> +                            unsigned int flags)
> +{
> +    int ret = -1;
> +    virDomainObjPtr vm = NULL;
> +
> +    virCheckFlags(0, -1);
> +
> +    if (pid_value != 1) {
> +        virReportError(VIR_ERR_INVALID_ARG,
> +                       _("only sending a signal to pid 1 is supported"));
> +        return -1;
> +    }
> +
> +    if (signum >= VIR_DOMAIN_PROCESS_SIGNAL_LAST) {
> +        virReportError(VIR_ERR_INVALID_ARG,
> +                       _("signum value %d is out of range"),
> +                       signum);
> +        return -1;
> +    }
> +
> +    if (!(vm = testDomObjFromDomain(dom)))
> +        goto cleanup;
> +
> +    /* do nothing */
> +    ret = 0;
> +
> + cleanup:
> +    virDomainObjEndAPI(&vm);
> +    return ret;
> +}
>
>  static int testNodeGetCellsFreeMemory(virConnectPtr conn,
>                                        unsigned long long *freemems,
> @@ -7027,6 +7061,7 @@ static virHypervisorDriver testHypervisorDriver = {
>      .domainScreenshot = testDomainScreenshot, /* 1.0.5 */
>      .domainGetMetadata = testDomainGetMetadata, /* 1.1.3 */
>      .domainSetMetadata = testDomainSetMetadata, /* 1.1.3 */
> +    .domainSendProcessSignal = testDomainSendProcessSignal, /* 5.5.0 */
>      .connectGetCPUModelNames = testConnectGetCPUModelNames, /* 1.1.3 */
>      .domainManagedSave = testDomainManagedSave, /* 1.1.4 */
>      .domainHasManagedSaveImage = testDomainHasManagedSaveImage, /* 1.1.4 */
> --
> 2.21.0
>
> --
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