[PATCH net-next] tools: ynl-gen: use big-endian netlink attribute types

["Asbjørn Sloth Tønnesen" <ast@fiberby.net>]

Change ynl-gen-c.py to use NLA_BE16 and NLA_BE32 types to represent
big-endian u16 and u32 ynl types.

Doing this enables those attributes to have range checks applied, as
the validator will then convert to host endianness prior to validation.

The autogenerated kernel/uapi code have been regenerated by running:
  ./tools/net/ynl/ynl-regen.sh -f

This changes the policy types of the following attributes:

  FOU_ATTR_PORT (NLA_U16 -> NLA_BE16)
  FOU_ATTR_PEER_PORT (NLA_U16 -> NLA_BE16)
    These two are used with nla_get_be16/nla_put_be16().

  MPTCP_PM_ADDR_ATTR_ADDR4 (NLA_U32 -> NLA_BE32)
    This one is used with nla_get_in_addr/nla_put_in_addr(),
    which uses nla_get_be32/nla_put_be32().

IOWs the generated changes are AFAICT aligned with their implementations.

The generated userspace code remains identical, and have been verified
by comparing the output generated by the following command:
  make -C tools/net/ynl/generated

Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
---
 net/ipv4/fou_nl.c          | 4 ++--
 net/mptcp/mptcp_pm_gen.c   | 2 +-
 tools/net/ynl/ynl-gen-c.py | 6 +++++-
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/fou_nl.c b/net/ipv4/fou_nl.c
index 98b90107b5abc..3d9614609b2d3 100644
--- a/net/ipv4/fou_nl.c
+++ b/net/ipv4/fou_nl.c
@@ -12,7 +12,7 @@
 
 /* Global operation policy for fou */
 const struct nla_policy fou_nl_policy[FOU_ATTR_IFINDEX + 1] = {
-	[FOU_ATTR_PORT] = { .type = NLA_U16, },
+	[FOU_ATTR_PORT] = { .type = NLA_BE16, },
 	[FOU_ATTR_AF] = { .type = NLA_U8, },
 	[FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
 	[FOU_ATTR_TYPE] = { .type = NLA_U8, },
@@ -21,7 +21,7 @@ const struct nla_policy fou_nl_policy[FOU_ATTR_IFINDEX + 1] = {
 	[FOU_ATTR_LOCAL_V6] = { .len = 16, },
 	[FOU_ATTR_PEER_V4] = { .type = NLA_U32, },
 	[FOU_ATTR_PEER_V6] = { .len = 16, },
-	[FOU_ATTR_PEER_PORT] = { .type = NLA_U16, },
+	[FOU_ATTR_PEER_PORT] = { .type = NLA_BE16, },
 	[FOU_ATTR_IFINDEX] = { .type = NLA_S32, },
 };
 
diff --git a/net/mptcp/mptcp_pm_gen.c b/net/mptcp/mptcp_pm_gen.c
index c30a2a90a1925..5a6b2b4510d37 100644
--- a/net/mptcp/mptcp_pm_gen.c
+++ b/net/mptcp/mptcp_pm_gen.c
@@ -14,7 +14,7 @@
 const struct nla_policy mptcp_pm_address_nl_policy[MPTCP_PM_ADDR_ATTR_IF_IDX + 1] = {
 	[MPTCP_PM_ADDR_ATTR_FAMILY] = { .type = NLA_U16, },
 	[MPTCP_PM_ADDR_ATTR_ID] = { .type = NLA_U8, },
-	[MPTCP_PM_ADDR_ATTR_ADDR4] = { .type = NLA_U32, },
+	[MPTCP_PM_ADDR_ATTR_ADDR4] = { .type = NLA_BE32, },
 	[MPTCP_PM_ADDR_ATTR_ADDR6] = NLA_POLICY_EXACT_LEN(16),
 	[MPTCP_PM_ADDR_ATTR_PORT] = { .type = NLA_U16, },
 	[MPTCP_PM_ADDR_ATTR_FLAGS] = { .type = NLA_U32, },
diff --git a/tools/net/ynl/ynl-gen-c.py b/tools/net/ynl/ynl-gen-c.py
index 717530bc9c52e..e26f2c3c40891 100755
--- a/tools/net/ynl/ynl-gen-c.py
+++ b/tools/net/ynl/ynl-gen-c.py
@@ -48,6 +48,7 @@ class Type(SpecAttr):
         self.attr = attr
         self.attr_set = attr_set
         self.type = attr['type']
+        self.nla_type = self.type
         self.checks = attr.get('checks', {})
 
         self.request = False
@@ -157,7 +158,7 @@ class Type(SpecAttr):
         return '{ .type = ' + policy + ', }'
 
     def attr_policy(self, cw):
-        policy = c_upper('nla-' + self.attr['type'])
+        policy = c_upper('nla-' + self.nla_type)
 
         spec = self._attr_policy(policy)
         cw.p(f"\t[{self.enum_name}] = {spec},")
@@ -300,6 +301,9 @@ class TypeScalar(Type):
         self.byte_order_comment = ''
         if 'byte-order' in attr:
             self.byte_order_comment = f" /* {attr['byte-order']} */"
+            if self.attr['byte-order'] == 'big-endian':
+                if self.type in {'u16', 'u32'}:
+                    self.nla_type = f'be{self.type[1:]}'
 
         if 'enum' in self.attr:
             enum = self.family.consts[self.attr['enum']]
-- 
2.45.2