Re: [PATCH v2 2/5] bpf: Add a bpf_sock_from_file helper
From: KP Singh <hidden>
Date: 2020-11-19 21:51:34
Also in:
bpf, lkml
On Thu, Nov 19, 2020 at 5:27 PM Florent Revest [off-list ref] wrote:
From: Florent Revest <redacted> While eBPF programs can check whether a file is a socket by file->f_op == &socket_file_ops, they cannot convert the void private_data pointer to a struct socket BTF pointer. In order to do this a new helper wrapping sock_from_file is added. This is useful to tracing programs but also other program types inheriting this set of helpers such as iterators or LSM programs. Signed-off-by: Florent Revest <redacted>
Acked-by: KP Singh <redacted> Some minor comments.
quoted hunk ↗ jump to hunk
--- include/uapi/linux/bpf.h | 7 +++++++ kernel/trace/bpf_trace.c | 20 ++++++++++++++++++++ scripts/bpf_helpers_doc.py | 4 ++++ tools/include/uapi/linux/bpf.h | 7 +++++++ 4 files changed, 38 insertions(+)diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 162999b12790..7d598f161dc0 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h@@ -3787,6 +3787,12 @@ union bpf_attr { * *ARG_PTR_TO_BTF_ID* of type *task_struct*. * Return * Pointer to the current task. + * + * struct socket *bpf_sock_from_file(struct file *file) + * Description + * If the given file contains a socket, returns the associated socket.
"If the given file is a socket" or "represents a socket" would fit better here.
+ * Return + * A pointer to a struct socket on success or NULL on failure.
NULL if the file is not a socket.