Linux: Don't use udev for joypad hotloading when running in a sandbox

udev doesn't work in sandboxes, notably the new Steam container runtime
as found notably on the Steam Deck, and in Flatpak/Snap packages.

Like SDL does, when we detect such a containerized environment, we fall
back to parsing `/dev/input` directly.
See smcv's comments in #76879 for details.

Fixes #76879.

(cherry picked from commit 788cb74cc6)
This commit is contained in:
Rémi Verschelde 2023-05-11 20:06:53 +02:00
parent 3762fe3d9d
commit 8a23fa41a8
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@ -32,6 +32,8 @@
#include "joypad_linux.h"
#include "core/os/os.h"
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
@ -77,13 +79,41 @@ void JoypadLinux::Joypad::reset() {
events.clear();
}
// This function is derived from SDL:
// https://github.com/libsdl-org/SDL/blob/main/src/core/linux/SDL_sandbox.c#L28-L45
static bool detect_sandbox() {
if (access("/.flatpak-info", F_OK) == 0) {
return true;
}
// For Snap, we check multiple variables because they might be set for
// unrelated reasons. This is the same thing WebKitGTK does.
if (OS::get_singleton()->has_environment("SNAP") && OS::get_singleton()->has_environment("SNAP_NAME") && OS::get_singleton()->has_environment("SNAP_REVISION")) {
return true;
}
if (access("/run/host/container-manager", F_OK) == 0) {
return true;
}
return false;
}
JoypadLinux::JoypadLinux(InputDefault *in) {
#ifdef UDEV_ENABLED
use_udev = initialize_libudev() == 0;
if (use_udev) {
print_verbose("JoypadLinux: udev enabled and loaded successfully.");
if (detect_sandbox()) {
// Linux binaries in sandboxes / containers need special handling because
// libudev doesn't work there. So we need to fallback to manual parsing
// of /dev/input in such case.
use_udev = false;
print_verbose("JoypadLinux: udev enabled, but detected incompatible sandboxed mode. Falling back to /dev/input to detect joypads.");
} else {
print_verbose("JoypadLinux: udev enabled, but couldn't be loaded. Falling back to /dev/input to detect joypads.");
use_udev = initialize_libudev() == 0;
if (use_udev) {
print_verbose("JoypadLinux: udev enabled and loaded successfully.");
} else {
print_verbose("JoypadLinux: udev enabled, but couldn't be loaded. Falling back to /dev/input to detect joypads.");
}
}
#else
print_verbose("JoypadLinux: udev disabled, parsing /dev/input to detect joypads.");