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>

---
Changelog:

v2:
- Re-implement to avoid adding a new Type attribute (Requested by Jakub).

v1: https://lore.kernel.org/netdev/20240913085555.134788-1-ast@fiberby.net/
---
 net/ipv4/fou_nl.c          | 4 ++--
 net/mptcp/mptcp_pm_gen.c   | 2 +-
 tools/net/ynl/ynl-gen-c.py | 5 ++++-
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/fou_nl.c b/net/ipv4/fou_nl.c
index 98b90107b5ab..3d9614609b2d 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 c30a2a90a192..5a6b2b4510d3 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 d64cb2b49c44..1a825b4081b2 100755
--- a/tools/net/ynl/ynl-gen-c.py
+++ b/tools/net/ynl/ynl-gen-c.py
@@ -167,7 +167,10 @@ class Type(SpecAttr):
         return '{ .type = ' + policy + ', }'
 
     def attr_policy(self, cw):
-        policy = c_upper('nla-' + self.attr['type'])
+        policy = f'NLA_{c_upper(self.type)}'
+        if self.attr.get('byte-order') == 'big-endian':
+            if self.type in {'u16', 'u32'}:
+                policy = f'NLA_BE{self.type[1:]}'
 
         spec = self._attr_policy(policy)
         cw.p(f"\t[{self.enum_name}] = {spec},")
-- 
2.45.2

On Thu, Oct 17, 2024 at 09:47:02AM +0000, Asbjørn Sloth Tønnesen wrote:
> 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>
> 
> ---
> Changelog:
> 
> v2:
> - Re-implement to avoid adding a new Type attribute (Requested by Jakub).
> 
> v1: https://lore.kernel.org/netdev/20240913085555.134788-1-ast@fiberby.net/

Thanks for addressing Jakub's review of v1.

Reviewed-by: Simon Horman <horms@kernel.org>