[PATCH bpf-next v2 20/28] HID: add implementation of bpf_hid_raw_request

Benjamin Tissoires
2022-03-04T17:35:14Z

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 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 | 1 +
3 files changed, 65 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-bpf.c b/drivers/hid/hid-bpf.c
index 8ae247fba5bc..b8c0060f3180 100644
--- a/drivers/hid/hid-bpf.c
+++ b/drivers/hid/hid-bpf.c
@@ -171,6 +171,68 @@ int hid_bpf_set_data(struct hid_device *hdev, u8 *buf, size_t buf_size, u64 offs
return n;
}

+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, enum bpf_hid_attach_type type,
struct hid_bpf_ctx *ctx, u8 *data, int size)
{
@@ -272,6 +334,7 @@ int __init hid_bpf_module_init(void)
.array_detached = hid_bpf_array_detached,
.hid_get_data = hid_bpf_get_data,
.hid_set_data = hid_bpf_set_data,
+ .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 d3f4499ee4cd..d0e015986e17 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..b2698df31e5b 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -946,6 +946,7 @@ __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);
--
2.35.1