tools: ynl: add scope qualifier for definitions

Using definitions in kernel policies is awkward right now.
On one hand we want defines for max values and such.
On the other we don't have a way of adding kernel-only defines.
Adding unnecessary defines to uAPI is a bad idea, we won't
be able to delete them. And when it comes to policy user
space should just query it via the policy dump, not use
hard coded defines.

Add a "scope" property to definitions, which will let us tell
the codegen that a definition is for kernel use only. Support
following values:
  - uapi: render into the uAPI header (default, today's behavior)
  - kernel: render to kernel header only
  - user: same as kernel but for the user-side generated header

Definitions may have a header property (definition is "external",
provided by existing header). Extend the scope to headers, too.
If definition has both scope and header properties we will only
generate the includes in the right scope.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://patch.msgid.link/20260510192904.3987113-8-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/Documentation/netlink/genetlink-c.yaml b/Documentation/netlink/genetlink-c.yaml
index 57f59fe23e3f8c66f70e2bdbe9a77168a43dca60..4ea31e8fc4d19d1cce81cad1c309de08455850da 100644 (file)
--- a/Documentation/netlink/genetlink-c.yaml
+++ b/Documentation/netlink/genetlink-c.yaml
@@ -69,6 +69,15 @@ properties:
         header:
           description: For C-compatible languages, header which already defines this value.
           type: string
+        scope:
+          description: |
+            Visibility of this definition. "uapi" (default) renders into
+            the uAPI header, "kernel" renders into the kernel-side
+            generated header, "user" renders into the user-side
+            generated header. When combined with `header:`, the
+            definition is not rendered, and the named header is
+            included only by code matching the scope.
+          enum: [ uapi, kernel, user ]
         type:
           enum: [ const, enum, flags ]
         doc:

diff --git a/Documentation/netlink/genetlink-legacy.yaml b/Documentation/netlink/genetlink-legacy.yaml
index 66fb8653a34423144c4a25e924de1f82a2e07590..f9c44747729ae3178c696c379553650f69543621 100644 (file)
--- a/Documentation/netlink/genetlink-legacy.yaml
+++ b/Documentation/netlink/genetlink-legacy.yaml
@@ -83,6 +83,15 @@ properties:
         header:
           description: For C-compatible languages, header which already defines this value.
           type: string
+        scope:
+          description: |
+            Visibility of this definition. "uapi" (default) renders into
+            the uAPI header, "kernel" renders into the kernel-side
+            generated header, "user" renders into the user-side
+            generated header. When combined with `header:`, the
+            definition is not rendered, and the named header is
+            included only by code matching the scope.
+          enum: [ uapi, kernel, user ]
         type:
           enum: [ const, enum, flags, struct ] # Trim
         doc:

diff --git a/Documentation/netlink/genetlink.yaml b/Documentation/netlink/genetlink.yaml
index a1194d5d93fc3c5e46df64e6e13c5ac1467e21be..d3f3f3399ddf850020fa1b8cd02b40039e7f5fdd 100644 (file)
--- a/Documentation/netlink/genetlink.yaml
+++ b/Documentation/netlink/genetlink.yaml
@@ -55,6 +55,15 @@ properties:
         header:
           description: For C-compatible languages, header which already defines this value.
           type: string
+        scope:
+          description: |
+            Visibility of this definition. "uapi" (default) renders into
+            the uAPI header, "kernel" renders into the kernel-side
+            generated header, "user" renders into the user-side
+            generated header. When combined with `header:`, the
+            definition is not rendered, and the named header is
+            included only by code matching the scope.
+          enum: [ uapi, kernel, user ]
         type:
           enum: [ const, enum, flags ]
         doc:

diff --git a/Documentation/netlink/netlink-raw.yaml b/Documentation/netlink/netlink-raw.yaml
index dd98dda55bd0fd6eec0f149fac7b19541d395d47..4c436b59a34be5f443e6a1475736c303ed7cdf82 100644 (file)
--- a/Documentation/netlink/netlink-raw.yaml
+++ b/Documentation/netlink/netlink-raw.yaml
@@ -87,6 +87,15 @@ properties:
         header:
           description: For C-compatible languages, header which already defines this value.
           type: string
+        scope:
+          description: |
+            Visibility of this definition. "uapi" (default) renders into
+            the uAPI header, "kernel" renders into the kernel-side
+            generated header, "user" renders into the user-side
+            generated header. When combined with `header:`, the
+            definition is not rendered, and the named header is
+            included only by code matching the scope.
+          enum: [ uapi, kernel, user ]
         type:
           enum: [ const, enum, flags, struct ] # Trim
         doc:

diff --git a/tools/net/ynl/pyynl/ynl_gen_c.py b/tools/net/ynl/pyynl/ynl_gen_c.py
index 0e1e486c1185a41630067c00271bd82c9307508b..cdc3646f2642c45883521e0aac56df1a42417c6f 100755 (executable)
--- a/tools/net/ynl/pyynl/ynl_gen_c.py
+++ b/tools/net/ynl/pyynl/ynl_gen_c.py
@@ -3212,6 +3212,8 @@ def render_uapi(family, cw):
     for const in family['definitions']:
         if const.get('header'):
             continue
+        if const.get('scope', 'uapi') != 'uapi':
+            continue
 
         if const['type'] != 'const':
             cw.writes_defines(defines)
@@ -3339,6 +3341,25 @@ def render_uapi(family, cw):
     cw.p(f'#endif /* {hdr_prot} */')
 
 
+def render_scoped_consts(family, cw, scope):
+    defines = []
+    for const in family['definitions']:
+        if const['type'] != 'const':
+            continue
+        if const.get('header'):
+            continue
+        if const.get('scope') != scope:
+            continue
+        name_pfx = const.get('name-prefix', f"{family.ident_name}-")
+        defines.append([
+            c_upper(family.get('c-define-name',
+                               f"{name_pfx}{const['name']}")),
+            const['value']])
+    if defines:
+        cw.writes_defines(defines)
+        cw.nl()
+
+
 def _render_user_ntf_entry(ri, op):
     if not ri.family.is_classic():
         ri.cw.block_start(line=f"[{op.enum_name}] = ")
@@ -3504,8 +3525,12 @@ def main():
             cw.p('#include "ynl.h"')
         headers = []
     for definition in parsed['definitions'] + parsed['attribute-sets']:
-        if 'header' in definition:
-            headers.append(definition['header'])
+        if 'header' not in definition:
+            continue
+        scope = definition.get('scope', 'uapi')
+        if scope != 'uapi' and scope != args.mode:
+            continue
+        headers.append(definition['header'])
     if args.mode == 'user':
         headers.append(parsed.uapi_header)
     seen_header = []
@@ -3522,6 +3547,7 @@ def main():
             for one in args.user_header:
                 cw.p(f'#include "{one}"')
         else:
+            render_scoped_consts(parsed, cw, 'user')
             cw.p('struct ynl_sock;')
             cw.nl()
             render_user_family(parsed, cw, True)
@@ -3529,6 +3555,7 @@ def main():
 
     if args.mode == "kernel":
         if args.header:
+            render_scoped_consts(parsed, cw, 'kernel')
             for _, struct in sorted(parsed.pure_nested_structs.items()):
                 if struct.request:
                     cw.p('/* Common nested types */')