Documentation/bpf/map_sk_storage.rst

11 ``BPF_MAP_TYPE_SK_STORAGE`` is used to provide socket-local storage for BPF
13 to be provided and acts as the handle for accessing the socket-local
15 locally with each socket instead of with the map. The kernel is responsible for
16 allocating storage for a socket when requested and for freeing the storage when
17 either the map or the socket is deleted.
22     socket-local storage.
37 Socket-local storage for ``map`` can be retrieved from socket ``sk`` using the
56 Socket-local storage for ``map`` can be deleted from socket ``sk`` using the
70 Socket-local storage for map ``map_fd`` can be added or updated locally to a
71 socket using the ``bpf_map_update_elem()`` libbpf function. The socket is
72 identified by a `socket` ``fd`` stored in the pointer ``key``. The pointer
73 ``value`` has the data to be added or updated to the socket ``fd``. The type
79 - ``BPF_ANY`` will create storage for `socket` ``fd`` or update existing storage.
80 - ``BPF_NOEXIST`` will create storage for `socket` ``fd`` only if it did not
82 - ``BPF_EXIST`` will update existing storage for `socket` ``fd`` if it already
94 Socket-local storage for map ``map_fd`` can be retrieved from a socket using
96 the socket identified by a `socket` ``fd`` stored in the pointer
106 Socket-local storage for map ``map_fd`` can be deleted from a socket using the
108 socket identified by a `socket` ``fd`` stored in the pointer ``key``. Returns
117 This snippet shows how to declare socket-local storage in a BPF program:
128 This snippet shows how to retrieve socket-local storage in a BPF program: