[PATCH bpf-next v3 14/17] HID: add implementation of bpf_hid_raw_request

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

Hook up BPF to hid_hw_raw_request.
Not much to report here except that we need to export hid_get_report
from hid-core so it gets available in hid-bpf.c

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

---

changes in v3:
- export HID_*_REPORT definitions in uapi as they are not following
  the specs

changes in v2:
- split the series by bpf/libbpf/hid/selftests and samples
---
 drivers/hid/hid-bpf.c    | 63 ++++++++++++++++++++++++++++++++++++++++
 drivers/hid/hid-core.c   |  3 +-
 include/linux/hid.h      | 12 ++------
 include/uapi/linux/hid.h | 10 +++++++
 4 files changed, 76 insertions(+), 12 deletions(-)

diff --git a/drivers/hid/hid-bpf.c b/drivers/hid/hid-bpf.c
index 650dd5e54919..66724aa2ff42 100644
--- a/drivers/hid/hid-bpf.c
+++ b/drivers/hid/hid-bpf.c
@@ -149,6 +149,68 @@ static int hid_bpf_set_bits(struct hid_device *hdev, u8 *buf, size_t buf_size, u
 	return n;
 }
 
+static int hid_bpf_raw_request(struct hid_device *hdev, u8 *buf, size_t size,
+			       u8 rtype, u8 reqtype)
+{
+	struct hid_report *report;
+	struct hid_report_enum *report_enum;
+	u8 *dma_data;
+	u32 report_len;
+	int ret;
+
+	/* check arguments */
+	switch (rtype) {
+	case HID_INPUT_REPORT:
+	case HID_OUTPUT_REPORT:
+	case HID_FEATURE_REPORT:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (reqtype) {
+	case HID_REQ_GET_REPORT:
+	case HID_REQ_GET_IDLE:
+	case HID_REQ_GET_PROTOCOL:
+	case HID_REQ_SET_REPORT:
+	case HID_REQ_SET_IDLE:
+	case HID_REQ_SET_PROTOCOL:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (size < 1)
+		return -EINVAL;
+
+	report_enum = hdev->report_enum + rtype;
+	report = hid_get_report(report_enum, buf);
+	if (!report)
+		return -EINVAL;
+
+	report_len = hid_report_len(report);
+
+	if (size > report_len)
+		size = report_len;
+
+	dma_data = kmemdup(buf, size, GFP_KERNEL);
+	if (!dma_data)
+		return -ENOMEM;
+
+	ret = hid_hw_raw_request(hdev,
+				 dma_data[0],
+				 dma_data,
+				 size,
+				 rtype,
+				 reqtype);
+
+	if (ret > 0)
+		memcpy(buf, dma_data, ret);
+
+	kfree(dma_data);
+	return ret;
+}
+
 static int hid_bpf_run_progs(struct hid_device *hdev, struct hid_bpf_ctx_kern *ctx)
 {
 	enum bpf_hid_attach_type type;
@@ -252,6 +314,7 @@ int __init hid_bpf_module_init(void)
 		.array_detach = hid_bpf_array_detach,
 		.hid_get_bits = hid_bpf_get_bits,
 		.hid_set_bits = hid_bpf_set_bits,
+		.hid_raw_request  = hid_bpf_raw_request,
 	};
 
 	bpf_hid_set_hooks(&hooks);
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 4f669dcddc08..f4b5d22f0831 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1686,8 +1686,7 @@ int hid_set_field(struct hid_field *field, unsigned offset, __s32 value)
 }
 EXPORT_SYMBOL_GPL(hid_set_field);
 
-static struct hid_report *hid_get_report(struct hid_report_enum *report_enum,
-		const u8 *data)
+struct hid_report *hid_get_report(struct hid_report_enum *report_enum, const u8 *data)
 {
 	struct hid_report *report;
 	unsigned int n = 0;	/* Normally report number is 0 */
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 7454e844324c..2f1b40d48265 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -316,15 +316,6 @@ struct hid_item {
 #define HID_BAT_ABSOLUTESTATEOFCHARGE	0x00850065
 
 #define HID_VD_ASUS_CUSTOM_MEDIA_KEYS	0xff310076
-/*
- * HID report types --- Ouch! HID spec says 1 2 3!
- */
-
-#define HID_INPUT_REPORT	0
-#define HID_OUTPUT_REPORT	1
-#define HID_FEATURE_REPORT	2
-
-#define HID_REPORT_TYPES	3
 
 /*
  * HID connect requests
@@ -344,7 +335,7 @@ struct hid_item {
  * HID device quirks.
  */
 
-/* 
+/*
  * Increase this if you need to configure more HID quirks at module load time
  */
 #define MAX_USBHID_BOOT_QUIRKS 4
@@ -946,6 +937,7 @@ __u32 hid_field_extract(const struct hid_device *hid, __u8 *report,
 		     unsigned offset, unsigned n);
 void implement(const struct hid_device *hid, u8 *report, unsigned int offset, unsigned int n,
 	       u32 value);
+struct hid_report *hid_get_report(struct hid_report_enum *report_enum, const u8 *data);
 
 #ifdef CONFIG_PM
 int hid_driver_suspend(struct hid_device *hdev, pm_message_t state);
diff --git a/include/uapi/linux/hid.h b/include/uapi/linux/hid.h
index b34492a87a8a..bb690343cf9a 100644
--- a/include/uapi/linux/hid.h
+++ b/include/uapi/linux/hid.h
@@ -42,6 +42,16 @@
 #define USB_INTERFACE_PROTOCOL_KEYBOARD	1
 #define USB_INTERFACE_PROTOCOL_MOUSE	2
 
+/*
+ * HID report types --- Ouch! HID spec says 1 2 3!
+ */
+
+#define HID_INPUT_REPORT	0
+#define HID_OUTPUT_REPORT	1
+#define HID_FEATURE_REPORT	2
+
+#define HID_REPORT_TYPES	3
+
 /*
  * HID class requests
  */
-- 
2.35.1