winebus.sys: Add code path to bypass udevd and use inotify.

In a container with a non-trivial user namespace, we cannot rely on libudev communicating with udevd as a way to monitor device nodes, for the following reasons: * If uid 0 from the host is not mapped to uid 0 in the container, libudev cannot authenticate netlink messages from the host, because their sender uid appears to be the overflowuid. Resolving this by mapping uid 0 into the container is not allowed when creating user namespaces as an unprivileged user, and even when running as a privileged user, it might be desirable for the real uid 0 to not be mapped as a way to harden the security boundary between container and host. * Depending on the container configuration, initial enumeration might not be able to read /run/udev from the host system. If it can't, sysfs attributes will still work because those are read directly from the kernel via sysfs, but udev properties coming from user-space rules (in particular ID_INPUT_JOYSTICK and friends) will appear to be missing. * The protocols between udevd and libudev (netlink messages for monitoring, and /run/udev for initial enumeration) are considered to be private to a particular version of udev, and are not a stable API; but in a container, we cannot expect that our copy of libudev is at exactly the same version as udevd on the host system. Sidestep this by adding a code path that continues to use libudev for the parts that work regardless of whether udevd is running or can be communicated with. Signed-off-by: Rémi Bernon <rbernon@codeweavers.com> Signed-off-by: Alexandre Julliard <julliard@winehq.org>

winebus.sys: Add code path to bypass udevd and use inotify.
ab3416c6 · Simon McVittie · Alexandre Julliard · 22dae167 · ab3416c6 · ab3416c6
Commit ab3416c6 authored Oct 20, 2021 by Simon McVittie Committed by Alexandre Julliard Oct 20, 2021
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bus_udev.c dlls/winebus.sys/bus_udev.c +0 -0

main.c dlls/winebus.sys/main.c +2 -0

unixlib.h dlls/winebus.sys/unixlib.h +1 -0

No files found.
--- a/dlls/winebus.sys/bus_udev.c
+++ b/dlls/winebus.sys/bus_udev.c
--- a/dlls/winebus.sys/main.c
+++ b/dlls/winebus.sys/main.c
@@ -730,6 +730,8 @@ static NTSTATUS udev_driver_init(void)
    if (bus_options.disable_hidraw) TRACE("UDEV hidraw devices disabled in registry\n");
    bus_options.disable_input = check_bus_option(L"DisableInput", 0);
    if (bus_options.disable_input) TRACE("UDEV input devices disabled in registry\n");
+    bus_options.disable_udevd = check_bus_option(L"DisableUdevd", 0);
+    if (bus_options.disable_udevd) TRACE("UDEV udevd use disabled in registry\n");

    return bus_main_thread_start(&bus);
 }

--- a/dlls/winebus.sys/unixlib.h
+++ b/dlls/winebus.sys/unixlib.h
@@ -56,6 +56,7 @@ struct udev_bus_options
 {
    BOOL disable_hidraw;
    BOOL disable_input;
+    BOOL disable_udevd;
 };

 struct iohid_bus_options