diff options
Diffstat (limited to 'include/linux/hid_bpf.h')
| -rw-r--r-- | include/linux/hid_bpf.h | 202 |
1 files changed, 139 insertions, 63 deletions
diff --git a/include/linux/hid_bpf.h b/include/linux/hid_bpf.h index eec2592dec12..9ca96fc90449 100644 --- a/include/linux/hid_bpf.h +++ b/include/linux/hid_bpf.h @@ -4,7 +4,8 @@ #define __HID_BPF_H #include <linux/bpf.h> -#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/srcu.h> #include <uapi/linux/hid.h> struct hid_device; @@ -20,15 +21,9 @@ struct hid_device; * struct hid_bpf_ctx - User accessible data for all HID programs * * ``data`` is not directly accessible from the context. We need to issue - * a call to ``hid_bpf_get_data()`` in order to get a pointer to that field. + * a call to hid_bpf_get_data() in order to get a pointer to that field. * - * All of these fields are currently read-only. - * - * @index: program index in the jump table. No special meaning (a smaller index - * doesn't mean the program will be executed before another program with - * a bigger index). - * @hid: the ``struct hid_device`` representing the device itself - * @report_type: used for ``hid_bpf_device_event()`` + * @hid: the &struct hid_device representing the device itself * @allocated_size: Allocated size of data. * * This is how much memory is available and can be requested @@ -45,76 +40,147 @@ struct hid_device; * ``size`` must always be less or equal than ``allocated_size`` (it is enforced * once all BPF programs have been run). * @retval: Return value of the previous program. + * + * ``hid`` and ``allocated_size`` are read-only, ``size`` and ``retval`` are read-write. */ struct hid_bpf_ctx { - __u32 index; - const struct hid_device *hid; + struct hid_device *hid; __u32 allocated_size; - enum hid_report_type report_type; union { __s32 retval; __s32 size; }; }; -/** - * enum hid_bpf_attach_flags - flags used when attaching a HIF-BPF program - * - * @HID_BPF_FLAG_NONE: no specific flag is used, the kernel choses where to - * insert the program - * @HID_BPF_FLAG_INSERT_HEAD: insert the given program before any other program - * currently attached to the device. This doesn't - * guarantee that this program will always be first - * @HID_BPF_FLAG_MAX: sentinel value, not to be used by the callers - */ -enum hid_bpf_attach_flags { - HID_BPF_FLAG_NONE = 0, - HID_BPF_FLAG_INSERT_HEAD = _BITUL(0), - HID_BPF_FLAG_MAX, -}; - -/* Following functions are tracepoints that BPF programs can attach to */ -int hid_bpf_device_event(struct hid_bpf_ctx *ctx); -int hid_bpf_rdesc_fixup(struct hid_bpf_ctx *ctx); - /* * Below is HID internal */ -/* internal function to call eBPF programs, not to be used by anybody */ -int __hid_bpf_tail_call(struct hid_bpf_ctx *ctx); - #define HID_BPF_MAX_PROGS_PER_DEV 64 #define HID_BPF_FLAG_MASK (((HID_BPF_FLAG_MAX - 1) << 1) - 1) -/* types of HID programs to attach to */ -enum hid_bpf_prog_type { - HID_BPF_PROG_TYPE_UNDEF = -1, - HID_BPF_PROG_TYPE_DEVICE_EVENT, /* an event is emitted from the device */ - HID_BPF_PROG_TYPE_RDESC_FIXUP, - HID_BPF_PROG_TYPE_MAX, -}; struct hid_report_enum; -struct hid_bpf_ops { +struct hid_ops { struct hid_report *(*hid_get_report)(struct hid_report_enum *report_enum, const u8 *data); int (*hid_hw_raw_request)(struct hid_device *hdev, 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); + enum hid_class_request reqtype, + u64 source, bool from_bpf); + int (*hid_hw_output_report)(struct hid_device *hdev, __u8 *buf, size_t len, + u64 source, bool from_bpf); int (*hid_input_report)(struct hid_device *hid, enum hid_report_type type, - u8 *data, u32 size, int interrupt); + u8 *data, u32 size, int interrupt, u64 source, bool from_bpf, + bool lock_already_taken); struct module *owner; const struct bus_type *bus_type; }; -extern struct hid_bpf_ops *hid_bpf_ops; +extern struct hid_ops *hid_ops; -struct hid_bpf_prog_list { - u16 prog_idx[HID_BPF_MAX_PROGS_PER_DEV]; - u8 prog_cnt; +/** + * struct hid_bpf_ops - A BPF struct_ops of callbacks allowing to attach HID-BPF + * programs to a HID device + * @hid_id: the HID uniq ID to attach to. This is writeable before ``load()``, and + * cannot be changed after + * @flags: flags used while attaching the struct_ops to the device. Currently only + * available value is %0 or ``BPF_F_BEFORE``. + * Writeable only before ``load()`` + */ +struct hid_bpf_ops { + /* hid_id needs to stay first so we can easily change it + * from userspace. + */ + int hid_id; + u32 flags; + + /* private: do not show up in the docs */ + struct list_head list; + + /* public: rest should show up in the docs */ + + /** + * @hid_device_event: called whenever an event is coming in from the device + * + * It has the following arguments: + * + * ``ctx``: The HID-BPF context as &struct hid_bpf_ctx + * + * Return: %0 on success and keep processing; a positive + * value to change the incoming size buffer; a negative + * error code to interrupt the processing of this event + * + * Context: Interrupt context. + */ + int (*hid_device_event)(struct hid_bpf_ctx *ctx, enum hid_report_type report_type, + u64 source); + + /** + * @hid_rdesc_fixup: called when the probe function parses the report descriptor + * of the HID device + * + * It has the following arguments: + * + * ``ctx``: The HID-BPF context as &struct hid_bpf_ctx + * + * Return: %0 on success and keep processing; a positive + * value to change the incoming size buffer; a negative + * error code to interrupt the processing of this device + */ + int (*hid_rdesc_fixup)(struct hid_bpf_ctx *ctx); + + /** + * @hid_hw_request: called whenever a hid_hw_raw_request() call is emitted + * on the HID device + * + * It has the following arguments: + * + * ``ctx``: The HID-BPF context as &struct hid_bpf_ctx + * + * ``reportnum``: the report number, as in hid_hw_raw_request() + * + * ``rtype``: the report type (``HID_INPUT_REPORT``, ``HID_FEATURE_REPORT``, + * ``HID_OUTPUT_REPORT``) + * + * ``reqtype``: the request + * + * ``source``: a u64 referring to a uniq but identifiable source. If %0, the + * kernel itself emitted that call. For hidraw, ``source`` is set + * to the associated ``struct file *``. + * + * Return: %0 to keep processing the request by hid-core; any other value + * stops hid-core from processing that event. A positive value should be + * returned with the number of bytes returned in the incoming buffer; a + * negative error code interrupts the processing of this call. + */ + int (*hid_hw_request)(struct hid_bpf_ctx *ctx, unsigned char reportnum, + enum hid_report_type rtype, enum hid_class_request reqtype, + u64 source); + + /** + * @hid_hw_output_report: called whenever a hid_hw_output_report() call is emitted + * on the HID device + * + * It has the following arguments: + * + * ``ctx``: The HID-BPF context as &struct hid_bpf_ctx + * + * ``source``: a u64 referring to a uniq but identifiable source. If %0, the + * kernel itself emitted that call. For hidraw, ``source`` is set + * to the associated ``struct file *``. + * + * Return: %0 to keep processing the request by hid-core; any other value + * stops hid-core from processing that event. A positive value should be + * returned with the number of bytes written to the device; a negative error + * code interrupts the processing of this call. + */ + int (*hid_hw_output_report)(struct hid_bpf_ctx *ctx, u64 source); + + + /* private: do not show up in the docs */ + struct hid_device *hdev; }; /* stored in each device */ @@ -124,34 +190,44 @@ struct hid_bpf { * to this HID device */ u32 allocated_data; - - struct hid_bpf_prog_list __rcu *progs[HID_BPF_PROG_TYPE_MAX]; /* attached BPF progs */ bool destroyed; /* prevents the assignment of any progs */ - spinlock_t progs_lock; /* protects RCU update of progs */ -}; - -/* specific HID-BPF link when a program is attached to a device */ -struct hid_bpf_link { - struct bpf_link link; - int hid_table_index; + struct hid_bpf_ops *rdesc_ops; + struct list_head prog_list; + struct mutex prog_list_lock; /* protects prog_list update */ + struct srcu_struct srcu; /* protects prog_list read-only access */ }; #ifdef CONFIG_HID_BPF u8 *dispatch_hid_bpf_device_event(struct hid_device *hid, enum hid_report_type type, u8 *data, - u32 *size, int interrupt); + u32 *size, int interrupt, u64 source, bool from_bpf); +int dispatch_hid_bpf_raw_requests(struct hid_device *hdev, + unsigned char reportnum, __u8 *buf, + u32 size, enum hid_report_type rtype, + enum hid_class_request reqtype, + u64 source, bool from_bpf); +int dispatch_hid_bpf_output_report(struct hid_device *hdev, __u8 *buf, u32 size, + u64 source, bool from_bpf); int hid_bpf_connect_device(struct hid_device *hdev); void hid_bpf_disconnect_device(struct hid_device *hdev); void hid_bpf_destroy_device(struct hid_device *hid); -void hid_bpf_device_init(struct hid_device *hid); +int hid_bpf_device_init(struct hid_device *hid); u8 *call_hid_bpf_rdesc_fixup(struct hid_device *hdev, u8 *rdesc, unsigned int *size); #else /* CONFIG_HID_BPF */ static inline u8 *dispatch_hid_bpf_device_event(struct hid_device *hid, enum hid_report_type type, - u8 *data, u32 *size, int interrupt) { return data; } + u8 *data, u32 *size, int interrupt, + u64 source, bool from_bpf) { return data; } +static inline int dispatch_hid_bpf_raw_requests(struct hid_device *hdev, + unsigned char reportnum, u8 *buf, + u32 size, enum hid_report_type rtype, + enum hid_class_request reqtype, + u64 source, bool from_bpf) { return 0; } +static inline int dispatch_hid_bpf_output_report(struct hid_device *hdev, __u8 *buf, u32 size, + u64 source, bool from_bpf) { return 0; } static inline int hid_bpf_connect_device(struct hid_device *hdev) { return 0; } static inline void hid_bpf_disconnect_device(struct hid_device *hdev) {} static inline void hid_bpf_destroy_device(struct hid_device *hid) {} -static inline void hid_bpf_device_init(struct hid_device *hid) {} +static inline int hid_bpf_device_init(struct hid_device *hid) { return 0; } #define call_hid_bpf_rdesc_fixup(_hdev, _rdesc, _size) \ ((u8 *)kmemdup(_rdesc, *(_size), GFP_KERNEL)) |