Commit bc30bb88 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

netlink: specs: support conditional operations 



Page pool code is compiled conditionally, but the operations
are part of the shared netlink family. We can handle this
by reporting empty list of pools or -EOPNOTSUPP / -ENOSYS
but the cleanest way seems to be removing the ops completely
at compilation time. That way user can see that the page
pool ops are not present using genetlink introspection.
Same way they'd check if the kernel is "new enough" to
support the ops.

Extend the specs with the ability to specify the config
condition under which op (and its policies, etc.) should
be hidden.

Reviewed-by: default avatarJiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231025162253.133159-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ea23fbd2

Documentation/netlink/genetlink-c.yaml

+5 −0
Original line number Diff line number Diff line
@@ -295,6 +295,11 @@ properties: 
              type: array

              items:

                enum: [ strict, dump, dump-strict ]

            config-cond:

              description: |

                Name of the kernel config option gating the presence of

                the operation, without the 'CONFIG_' prefix.

              type: string

            do: &subop-type

              description: Main command handler.

              type: object

Documentation/netlink/genetlink-legacy.yaml

+5 −0
Original line number Diff line number Diff line
@@ -346,6 +346,11 @@ properties: 
              type: array

              items:

                enum: [ strict, dump, dump-strict ]

            config-cond:

              description: |

                Name of the kernel config option gating the presence of

                the operation, without the 'CONFIG_' prefix.

              type: string

            # Start genetlink-legacy

            fixed-header: *fixed-header

            # End genetlink-legacy

Documentation/netlink/genetlink.yaml

+5 −0
Original line number Diff line number Diff line
@@ -264,6 +264,11 @@ properties: 
              type: array

              items:

                enum: [ strict, dump, dump-strict ]

            config-cond:

              description: |

                Name of the kernel config option gating the presence of

                the operation, without the 'CONFIG_' prefix.

              type: string

            do: &subop-type

              description: Main command handler.

              type: object

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

+22 −0
Original line number Diff line number Diff line
@@ -1162,6 +1162,7 @@ class CodeWriter: 
        self._block_end = False

        self._silent_block = False

        self._ind = 0

        self._ifdef_block = None

        if out_file is None:

            self._out = os.sys.stdout

        else:
@@ -1202,6 +1203,8 @@ class CodeWriter: 
        if self._silent_block:

            ind += 1

        self._silent_block = line.endswith(')') and CodeWriter._is_cond(line)

        if line[0] == '#':

            ind = 0

        if add_ind:

            ind += add_ind

        self._out.write('\t' * ind + line + '\n')
@@ -1328,6 +1331,19 @@ class CodeWriter: 
            line += '= ' + str(one[1]) + ','

            self.p(line)



    def ifdef_block(self, config):

        config_option = None

        if config:

            config_option = 'CONFIG_' + c_upper(config)

        if self._ifdef_block == config_option:

            return



        if self._ifdef_block:

            self.p('#endif /* ' + self._ifdef_block + ' */')

        if config_option:

            self.p('#ifdef ' + config_option)

        self._ifdef_block = config_option





scalars = {'u8', 'u16', 'u32', 'u64', 's32', 's64', 'uint', 'sint'}
@@ -2006,10 +2022,13 @@ def print_req_policy_fwd(cw, struct, ri=None, terminate=True): 




def print_req_policy(cw, struct, ri=None):

    if ri and ri.op:

        cw.ifdef_block(ri.op.get('config-cond', None))

    print_req_policy_fwd(cw, struct, ri=ri, terminate=False)

    for _, arg in struct.member_list():

        arg.attr_policy(cw)

    cw.p("};")

    cw.ifdef_block(None)

    cw.nl()
@@ -2127,6 +2146,7 @@ def print_kernel_op_table(family, cw): 
            if op.is_async:

                continue



            cw.ifdef_block(op.get('config-cond', None))

            cw.block_start()

            members = [('cmd', op.enum_name)]

            if 'dont-validate' in op:
@@ -2157,6 +2177,7 @@ def print_kernel_op_table(family, cw): 
                if op.is_async or op_mode not in op:

                    continue



                cw.ifdef_block(op.get('config-cond', None))

                cw.block_start()

                members = [('cmd', op.enum_name)]

                if 'dont-validate' in op:
@@ -2192,6 +2213,7 @@ def print_kernel_op_table(family, cw): 
                members.append(('flags', ' | '.join([c_upper('genl-' + x) for x in flags])))

                cw.write_struct_init(members)

                cw.block_end(line=',')

    cw.ifdef_block(None)



    cw.block_end(line=';')

    cw.nl()