Commit 668c1ac8 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

tools: ynl-gen: support full range of min/max checks for integer values 

Extend the support to full range of min/max checks.
None of the existing YNL families required complex integer validation.

The support is less than trivial, because we try to keep struct nla_policy
tiny the min/max members it holds in place are s16. Meaning we can only
express checks in range of s16. For larger ranges we need to define
a structure and link it in the policy.

Link: https://lore.kernel.org/r/20231018163917.2514503-3-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ee0a4cfc

Documentation/netlink/genetlink-c.yaml

+3 −0
Original line number Diff line number Diff line
@@ -184,6 +184,9 @@ properties: 
                  min:

                    description: Min value for an integer attribute.

                    type: integer

                  max:

                    description: Max value for an integer attribute.

                    type: integer

                  min-len:

                    description: Min length for a binary attribute.

                    $ref: '#/$defs/len-or-define'

Documentation/netlink/genetlink-legacy.yaml

+3 −0
Original line number Diff line number Diff line
@@ -227,6 +227,9 @@ properties: 
                  min:

                    description: Min value for an integer attribute.

                    type: integer

                  max:

                    description: Max value for an integer attribute.

                    type: integer

                  min-len:

                    description: Min length for a binary attribute.

                    $ref: '#/$defs/len-or-define'

Documentation/netlink/genetlink.yaml

+3 −0
Original line number Diff line number Diff line
@@ -157,6 +157,9 @@ properties: 
                  min:

                    description: Min value for an integer attribute.

                    type: integer

                  max:

                    description: Max value for an integer attribute.

                    type: integer

                  min-len:

                    description: Min length for a binary attribute.

                    $ref: '#/$defs/len-or-define'

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

+59 −7
Original line number Diff line number Diff line
@@ -47,6 +47,7 @@ class Type(SpecAttr): 


        if 'len' in attr:

            self.len = attr['len']



        if 'nested-attributes' in attr:

            self.nested_attrs = attr['nested-attributes']

            if self.nested_attrs == family.name:
@@ -262,6 +263,27 @@ class TypeScalar(Type): 
        if 'byte-order' in attr:

            self.byte_order_comment = f" /* {attr['byte-order']} */"



        if 'enum' in self.attr:

            enum = self.family.consts[self.attr['enum']]

            low, high = enum.value_range()

            if 'min' not in self.checks:

                if low != 0 or self.type[0] == 's':

                    self.checks['min'] = low

            if 'max' not in self.checks:

                self.checks['max'] = high



        if 'min' in self.checks and 'max' in self.checks:

            if self.checks['min'] > self.checks['max']:

                raise Exception(f'Invalid limit for "{self.name}" min: {self.checks["min"]} max: {self.checks["max"]}')

            self.checks['range'] = True



        low = min(self.checks.get('min', 0), self.checks.get('max', 0))

        high = max(self.checks.get('min', 0), self.checks.get('max', 0))

        if low < 0 and self.type[0] == 'u':

            raise Exception(f'Invalid limit for "{self.name}" negative limit for unsigned type')

        if low < -32768 or high > 32767:

            self.checks['full-range'] = True



        # Added by resolve():

        self.is_bitfield = None

        delattr(self, "is_bitfield")
@@ -301,14 +323,14 @@ class TypeScalar(Type): 
                flag_cnt = len(flags['entries'])

                mask = (1 << flag_cnt) - 1

            return f"NLA_POLICY_MASK({policy}, 0x{mask:x})"

        elif 'full-range' in self.checks:

            return f"NLA_POLICY_FULL_RANGE({policy}, &{c_lower(self.enum_name)}_range)"

        elif 'range' in self.checks:

            return f"NLA_POLICY_RANGE({policy}, {self.checks['min']}, {self.checks['max']})"

        elif 'min' in self.checks:

            return f"NLA_POLICY_MIN({policy}, {self.checks['min']})"

        elif 'enum' in self.attr:

            enum = self.family.consts[self.attr['enum']]

            low, high = enum.value_range()

            if low == 0:

                return f"NLA_POLICY_MAX({policy}, {high})"

            return f"NLA_POLICY_RANGE({policy}, {low}, {high})"

        elif 'max' in self.checks:

            return f"NLA_POLICY_MAX({policy}, {self.checks['max']})"

        return super()._attr_policy(policy)



    def _attr_typol(self):
@@ -1241,7 +1263,7 @@ class CodeWriter: 
        for one in members:

            line = '.' + one[0]

            line += '\t' * ((longest - len(one[0]) - 1 + 7) // 8)

            line += '= ' + one[1] + ','

            line += '= ' + str(one[1]) + ','

            self.p(line)
@@ -1940,6 +1962,34 @@ def policy_should_be_static(family): 
    return family.kernel_policy == 'split' or kernel_can_gen_family_struct(family)





def print_kernel_policy_ranges(family, cw):

    first = True

    for _, attr_set in family.attr_sets.items():

        if attr_set.subset_of:

            continue



        for _, attr in attr_set.items():

            if not attr.request:

                continue

            if 'full-range' not in attr.checks:

                continue



            if first:

                cw.p('/* Integer value ranges */')

                first = False



            sign = '' if attr.type[0] == 'u' else '_signed'

            cw.block_start(line=f'struct netlink_range_validation{sign} {c_lower(attr.enum_name)}_range =')

            members = []

            if 'min' in attr.checks:

                members.append(('min', attr.checks['min']))

            if 'max' in attr.checks:

                members.append(('max', attr.checks['max']))

            cw.write_struct_init(members)

            cw.block_end(line=';')

            cw.nl()





def print_kernel_op_table_fwd(family, cw, terminate):

    exported = not kernel_can_gen_family_struct(family)
@@ -2479,6 +2529,8 @@ def main(): 
            print_kernel_mcgrp_hdr(parsed, cw)

            print_kernel_family_struct_hdr(parsed, cw)

        else:

            print_kernel_policy_ranges(parsed, cw)



            for _, struct in sorted(parsed.pure_nested_structs.items()):

                if struct.request:

                    cw.p('/* Common nested types */')