1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/hid/bpf/progs/Logitech__SpaceNavigator.bpf.c b/drivers/hid/bpf/progs/Logitech__SpaceNavigator.bpf.c
new file mode 100644
index 000000000000..b17719d6d9c7
--- /dev/null
+++ b/drivers/hid/bpf/progs/Logitech__SpaceNavigator.bpf.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2025 Curran Muhlberger
+ */
+
+#include "vmlinux.h"
+#include "hid_bpf.h"
+#include "hid_bpf_helpers.h"
+#include <bpf/bpf_tracing.h>
+
+#define VID_LOGITECH 0x046D
+#define PID_SPACENAVIGATOR 0xC626
+
+HID_BPF_CONFIG(
+	HID_DEVICE(BUS_USB, HID_GROUP_ANY, VID_LOGITECH, PID_SPACENAVIGATOR)
+);
+
+/*
+ * The 3Dconnexion SpaceNavigator 3D Mouse is a multi-axis controller with 6
+ * axes (grouped as X,Y,Z and Rx,Ry,Rz).  Axis data is absolute, but the report
+ * descriptor erroneously declares it to be relative.  We fix the report
+ * descriptor to mark both axis collections as absolute.
+ *
+ * The kernel attempted to fix this in commit 24985cf68612 (HID: support
+ * Logitech/3DConnexion SpaceTraveler and SpaceNavigator), but the descriptor
+ * data offsets are incorrect for at least some SpaceNavigator units.
+ */
+
+SEC(HID_BPF_RDESC_FIXUP)
+int BPF_PROG(hid_fix_rdesc, struct hid_bpf_ctx *hctx)
+{
+	__u8 *data = hid_bpf_get_data(hctx, 0 /* offset */, 4096 /* size */);
+
+	if (!data)
+		return 0; /* EPERM check */
+
+	/* Offset of Input item in X,Y,Z and Rx,Ry,Rz collections for all known
+	 * firmware variants.
+	 * - 2009 model: X,Y,Z @ 32-33, Rx,Ry,Rz @ 49-50 (fixup originally
+	 *   applied in kernel)
+	 * - 2016 model (size==228): X,Y,Z @ 36-37, Rx,Ry,Rz @ 53-54
+	 *
+	 * The descriptor size of the 2009 model is not known, and there is evidence
+	 * for at least two other variants (with sizes 202 & 217) besides the 2016
+	 * model, so we try all known offsets regardless of descriptor size.
+	 */
+	const u8 offsets[] = {32, 36, 49, 53};
+
+	for (size_t idx = 0; idx < ARRAY_SIZE(offsets); idx++) {
+		u8 offset = offsets[idx];
+
+		/* if Input (Data,Var,Rel) , make it Input (Data,Var,Abs) */
+		if (data[offset] == 0x81 && data[offset + 1] == 0x06)
+			data[offset + 1] = 0x02;
+	}
+
+	return 0;
+}
+
+HID_BPF_OPS(logitech_spacenavigator) = {
+	.hid_rdesc_fixup = (void *)hid_fix_rdesc,
+};
+
+SEC("syscall")
+int probe(struct hid_bpf_probe_args *ctx)
+{
+	/* Ensure report descriptor size matches one of the known variants. */
+	if (ctx->rdesc_size != 202 &&
+	    ctx->rdesc_size != 217 &&
+	    ctx->rdesc_size != 228) {
+		ctx->retval = -EINVAL;
+		return 0;
+	}
+
+	/* Check whether the kernel has already applied the fix. */
+	if ((ctx->rdesc[32] == 0x81 && ctx->rdesc[33] == 0x02 &&
+	     ctx->rdesc[49] == 0x81 && ctx->rdesc[50] == 0x02) ||
+	    (ctx->rdesc[36] == 0x81 && ctx->rdesc[37] == 0x02 &&
+	     ctx->rdesc[53] == 0x81 && ctx->rdesc[54] == 0x02))
+		ctx->retval = -EINVAL;
+	else
+		ctx->retval = 0;
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";