Commit ba980f8d authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

netlink: specs: support generating code for genl socket priv 

The family struct is auto-generated for new families, support
use of the sock_priv_* mechanism added in commit a7311324
("genetlink: introduce per-sock family private storage").

For example if the family wants to use struct sk_buff as its
private struct (unrealistic but just for illustration), it would
add to its spec:

  kernel-family:
    headers: [ "linux/skbuff.h" ]
    sock-priv: struct sk_buff

ynl-gen-c will declare the appropriate priv size and hook
in function prototypes to be implemented by the family.

Link: https://lore.kernel.org/r/20240308190319.2523704-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent a0d94296

Documentation/netlink/genetlink-c.yaml

+19 −0
Original line number Diff line number Diff line
@@ -378,3 +378,22 @@ properties: 
              type: string

            # End genetlink-c

            flags: *cmd_flags



  kernel-family:

    description: Additional global attributes used for kernel C code generation.

    type: object

    additionalProperties: False

    properties:

      headers:

        description: |

          List of extra headers which should be included in the source

          of the generated code.

        type: array

        items:

          type: string

      sock-priv:

        description: |

          Literal name of the type which is used within the kernel

          to store the socket state. The type / structure is internal

          to the kernel, and is not defined in the spec.

        type: string

Documentation/netlink/genetlink-legacy.yaml

+19 −0
Original line number Diff line number Diff line
@@ -439,3 +439,22 @@ properties: 
              type: string

            # End genetlink-c

            flags: *cmd_flags



  kernel-family:

    description: Additional global attributes used for kernel C code generation.

    type: object

    additionalProperties: False

    properties:

      headers:

        description: |

          List of extra headers which should be included in the source

          of the generated code.

        type: array

        items:

          type: string

      sock-priv:

        description: |

          Literal name of the type which is used within the kernel

          to store the socket state. The type / structure is internal

          to the kernel, and is not defined in the spec.

        type: string

Documentation/netlink/genetlink.yaml

+19 −0
Original line number Diff line number Diff line
@@ -328,3 +328,22 @@ properties: 
                The name for the group, used to form the define and the value of the define.

              type: string

            flags: *cmd_flags



  kernel-family:

    description: Additional global attributes used for kernel C code generation.

    type: object

    additionalProperties: False

    properties:

      headers:

        description: |

          List of extra headers which should be included in the source

          of the generated code.

        type: array

        items:

          type: string

      sock-priv:

        description: |

          Literal name of the type which is used within the kernel

          to store the socket state. The type / structure is internal

          to the kernel, and is not defined in the spec.

        type: string

tools/net/ynl/lib/nlspec.py

+2 −0
Original line number Diff line number Diff line
@@ -418,6 +418,7 @@ class SpecFamily(SpecElement): 
        consts     dict of all constants/enums

        fixed_header  string, optional name of family default fixed header struct

        mcast_groups  dict of all multicast groups (index by name)

        kernel_family   dict of kernel family attributes

    """

    def __init__(self, spec_path, schema_path=None, exclude_ops=None):

        with open(spec_path, "r") as stream:
@@ -461,6 +462,7 @@ class SpecFamily(SpecElement): 
        self.ntfs = collections.OrderedDict()

        self.consts = collections.OrderedDict()

        self.mcast_groups = collections.OrderedDict()

        self.kernel_family = collections.OrderedDict(self.yaml.get('kernel-family', {}))



        last_exception = None

        while len(self._resolution_list) > 0:

tools/net/ynl/ynl-gen-c.py

+10 −0
Original line number Diff line number Diff line
@@ -2342,6 +2342,10 @@ def print_kernel_family_struct_hdr(family, cw): 


    cw.p(f"extern struct genl_family {family.c_name}_nl_family;")

    cw.nl()

    if 'sock-priv' in family.kernel_family:

        cw.p(f'void {family.c_name}_nl_sock_priv_init({family.kernel_family["sock-priv"]} *priv);')

        cw.p(f'void {family.c_name}_nl_sock_priv_destroy({family.kernel_family["sock-priv"]} *priv);')

        cw.nl()





def print_kernel_family_struct_src(family, cw):
@@ -2363,6 +2367,11 @@ def print_kernel_family_struct_src(family, cw): 
    if family.mcgrps['list']:

        cw.p(f'.mcgrps\t\t= {family.c_name}_nl_mcgrps,')

        cw.p(f'.n_mcgrps\t= ARRAY_SIZE({family.c_name}_nl_mcgrps),')

    if 'sock-priv' in family.kernel_family:

        cw.p(f'.sock_priv_size\t= sizeof({family.kernel_family["sock-priv"]}),')

        # Force cast here, actual helpers take pointer to the real type.

        cw.p(f'.sock_priv_init\t= (void *){family.c_name}_nl_sock_priv_init,')

        cw.p(f'.sock_priv_destroy = (void *){family.c_name}_nl_sock_priv_destroy,')

    cw.block_end(';')
@@ -2659,6 +2668,7 @@ def main(): 
                cw.p(f'#include "{os.path.basename(args.out_file[:-2])}.h"')

            cw.nl()

        headers = ['uapi/' + parsed.uapi_header]

        headers += parsed.kernel_family.get('headers', [])

    else:

        cw.p('#include <stdlib.h>')

        cw.p('#include <string.h>')