From MSDN on CreateServiceW:
The returned handle is only valid for the process that called
CreateService. It can be closed by calling the CloseServiceHandle
function.
This isn't an actual kernel object to be closed with CloseHandle.
Change-Id: Iee225a666576d57a6c4864abef20206d54cbbce2
Reviewed-on: https://go-review.googlesource.com/c/sys/+/198298
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
The SCM can be locked by NT. While traditionally any process could lock
the SCM using "LockServiceDatabase", Microsoft removed this
functionality because it created so many bugs, and that function now
does nothing. However, the system itself, via the "NT Service Control
Manager", is still allowed to lock the SCM.
For example, at boot time on Windows 8.1, the SCM is locked after a
service is started until that service reports itself in a running state.
This poses a bit of a problem: it's useful to install device drivers
from inside services as part of their initialization, and mark the
service as having started only after the device has installed. But
device installation might potentially load new drivers, and drivers
themselves exist as a special type of service. This means that if a
driver is installed before marking the service as started, the entire
SCM will deadlock, and the OS will be partially unresponsive for a
minute or two.
Fortunately Microsoft supplies an API for exactly this purpose. The
solution is to mark the service as started before installing device
drivers, only under the circumstance that the SCM is locked. So, this
commit adds the proper API for determining this. It can be used like
this:
if m, err := mgr.Connect(); err == nil {
if lockStatus, err := m.LockStatus(); err == nil && lockStatus.IsLocked {
log.Printf("SCM locked for %v by %s, marking service as started", lockStatus.Age, lockStatus.Owner)
changes <- svc.Status{State: svc.Running}
}
m.Disconnect()
}
deviceDriver.Install()
This creates messages like the following, indicating that this API
works:
SCM locked for 1s by .\NT Service Control Manager, marking service as started
Change-Id: Ic2f5b387e23efc3a287b2ab96ff84b357b712e36
Reviewed-on: https://go-review.googlesource.com/c/sys/+/180977
Run-TryBot: Jason Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
Many service attributes are settable using the ordinary CreateService
function, but ones added later in Windows need to be set using the
ChangeServiceConfig2 function. One of these is the Description field,
which is nicely plumbed behind the scenes, so that users of the API can
set it, and the mgr package will just figure out what to do with it.
Another one that works exactly the same way is SidType. Support for its
constants was added in 30999d6 ("windows: add missing service
constants"), but it wasn't actually built into the mgr package's
configuration struct, creating inconstancies in interface.
This commit rectifies that by adding proper support to mgr's config
struct.
Change-Id: I4f148f2d2477a03a65e8a571a8401392f6fe9f28
Reviewed-on: https://go-review.googlesource.com/c/sys/+/180978
Run-TryBot: Jason Donenfeld <Jason@zx2c4.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matt Layher <mdlayher@gmail.com>
Reviewed-by: Alex Brainman <alex.brainman@gmail.com>
The args passed to Mgr.CreateService end up as the command-line
arguments (available via os.Args), not as the args passed to
Svc.Handler.Execute.
Fixesgolang/go#20440
Change-Id: I55a1ec3432b377082c018fe960114c96350e8978
Reviewed-on: https://go-review.googlesource.com/43714
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
