@@ -179,7 +179,7 @@ Available API that can be used in syscall HID-BPF programs:
-----------------------------------------------------------
.. kernel-doc:: drivers/hid/bpf/hid_bpf_dispatch.c
- :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_allocate_context hid_bpf_release_context
+ :functions: hid_bpf_attach_prog hid_bpf_hw_request hid_bpf_hw_output_report hid_bpf_allocate_context hid_bpf_release_context
General overview of a HID-BPF program
=====================================
@@ -376,6 +376,46 @@ hid_bpf_release_context(struct hid_bpf_ctx *ctx)
put_device(&hid->dev);
}
+static int
+__hid_bpf_hw_check_params(struct hid_bpf_ctx *ctx, __u8 *buf, size_t *buf__sz,
+ enum hid_report_type rtype)
+{
+ struct hid_report_enum *report_enum;
+ struct hid_report *report;
+ struct hid_device *hdev;
+ u32 report_len;
+
+ /* check arguments */
+ if (!ctx || !hid_bpf_ops || !buf)
+ return -EINVAL;
+
+ switch (rtype) {
+ case HID_INPUT_REPORT:
+ case HID_OUTPUT_REPORT:
+ case HID_FEATURE_REPORT:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (*buf__sz < 1)
+ return -EINVAL;
+
+ hdev = (struct hid_device *)ctx->hid; /* discard const */
+
+ report_enum = hdev->report_enum + rtype;
+ report = hid_bpf_ops->hid_get_report(report_enum, buf);
+ if (!report)
+ return -EINVAL;
+
+ report_len = hid_report_len(report);
+
+ if (*buf__sz > report_len)
+ *buf__sz = report_len;
+
+ return 0;
+}
+
/**
* hid_bpf_hw_request - Communicate with a HID device
*
@@ -392,24 +432,14 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
enum hid_report_type rtype, enum hid_class_request reqtype)
{
struct hid_device *hdev;
- struct hid_report *report;
- struct hid_report_enum *report_enum;
+ size_t size = buf__sz;
u8 *dma_data;
- u32 report_len;
int ret;
/* check arguments */
- if (!ctx || !hid_bpf_ops || !buf)
- return -EINVAL;
-
- switch (rtype) {
- case HID_INPUT_REPORT:
- case HID_OUTPUT_REPORT:
- case HID_FEATURE_REPORT:
- break;
- default:
- return -EINVAL;
- }
+ ret = __hid_bpf_hw_check_params(ctx, buf, &size, rtype);
+ if (ret)
+ return ret;
switch (reqtype) {
case HID_REQ_GET_REPORT:
@@ -423,29 +453,16 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
return -EINVAL;
}
- if (buf__sz < 1)
- return -EINVAL;
-
hdev = (struct hid_device *)ctx->hid; /* discard const */
- report_enum = hdev->report_enum + rtype;
- report = hid_bpf_ops->hid_get_report(report_enum, buf);
- if (!report)
- return -EINVAL;
-
- report_len = hid_report_len(report);
-
- if (buf__sz > report_len)
- buf__sz = report_len;
-
- dma_data = kmemdup(buf, buf__sz, GFP_KERNEL);
+ dma_data = kmemdup(buf, size, GFP_KERNEL);
if (!dma_data)
return -ENOMEM;
ret = hid_bpf_ops->hid_hw_raw_request(hdev,
dma_data[0],
dma_data,
- buf__sz,
+ size,
rtype,
reqtype);
@@ -455,6 +472,42 @@ hid_bpf_hw_request(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz,
kfree(dma_data);
return ret;
}
+
+/**
+ * hid_bpf_hw_output_report - Send an output report to a HID device
+ *
+ * @ctx: the HID-BPF context previously allocated in hid_bpf_allocate_context()
+ * @buf: a %PTR_TO_MEM buffer
+ * @buf__sz: the size of the data to transfer
+ *
+ * @returns the number of bytes transferred on success, a negative error code otherwise.
+ */
+__bpf_kfunc int
+hid_bpf_hw_output_report(struct hid_bpf_ctx *ctx, __u8 *buf, size_t buf__sz)
+{
+ struct hid_device *hdev;
+ size_t size = buf__sz;
+ u8 *dma_data;
+ int ret;
+
+ /* check arguments */
+ ret = __hid_bpf_hw_check_params(ctx, buf, &size, HID_OUTPUT_REPORT);
+ if (ret)
+ return ret;
+
+ hdev = (struct hid_device *)ctx->hid; /* discard const */
+
+ dma_data = kmemdup(buf, size, GFP_KERNEL);
+ if (!dma_data)
+ return -ENOMEM;
+
+ ret = hid_bpf_ops->hid_hw_output_report(hdev,
+ dma_data,
+ size);
+
+ kfree(dma_data);
+ return ret;
+}
__bpf_kfunc_end_defs();
/*
@@ -488,6 +541,7 @@ BTF_ID_FLAGS(func, hid_bpf_attach_prog)
BTF_ID_FLAGS(func, hid_bpf_allocate_context, KF_ACQUIRE | KF_RET_NULL)
BTF_ID_FLAGS(func, hid_bpf_release_context, KF_RELEASE)
BTF_ID_FLAGS(func, hid_bpf_hw_request)
+BTF_ID_FLAGS(func, hid_bpf_hw_output_report)
BTF_KFUNCS_END(hid_bpf_syscall_kfunc_ids)
static const struct btf_kfunc_id_set hid_bpf_syscall_kfunc_set = {
@@ -2974,6 +2974,7 @@ EXPORT_SYMBOL_GPL(hid_check_keys_pressed);
static struct hid_bpf_ops hid_ops = {
.hid_get_report = hid_get_report,
.hid_hw_raw_request = hid_hw_raw_request,
+ .hid_hw_output_report = hid_hw_output_report,
.owner = THIS_MODULE,
.bus_type = &hid_bus_type,
};
@@ -103,6 +103,7 @@ struct hid_bpf_ops {
unsigned char reportnum, __u8 *buf,
size_t len, enum hid_report_type rtype,
enum hid_class_request reqtype);
+ int (*hid_hw_output_report)(struct hid_device *hdev, __u8 *buf, size_t len);
struct module *owner;
const struct bus_type *bus_type;
};
We currently only export hid_hw_raw_request() as a BPF kfunc. However, some devices require an explicit write on the Output Report instead of the use of the control channel. So also export hid_hw_output_report to BPF Signed-off-by: Benjamin Tissoires <bentiss@kernel.org> --- no changes in v2 --- Documentation/hid/hid-bpf.rst | 2 +- drivers/hid/bpf/hid_bpf_dispatch.c | 112 +++++++++++++++++++++++++++---------- drivers/hid/hid-core.c | 1 + include/linux/hid_bpf.h | 1 + 4 files changed, 86 insertions(+), 30 deletions(-)