tools: ynl: don't use genlmsghdr in classic netlink

Make sure the codegen calls the right YNL lib helper to start
the request based on family type. Classic netlink request must
not include the genl header.

Conversely don't expect genl headers in the responses.

Reviewed-by: Jacob Keller <[email protected]>
Reviewed-by: Donald Hunter <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: kuba-moo

tools/net/ynl/lib/ynl-priv.h

@@ -94,6 +94,9 @@ struct ynl_ntf_base_type {
 	unsigned char data[] __attribute__((aligned(8)));
 };
 
+struct nlmsghdr *ynl_msg_start_req(struct ynl_sock *ys, __u32 id);
+struct nlmsghdr *ynl_msg_start_dump(struct ynl_sock *ys, __u32 id);
+
 struct nlmsghdr *
 ynl_gemsg_start_req(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version);
 struct nlmsghdr *

tools/net/ynl/lib/ynl.c

@@ -451,14 +451,14 @@ ynl_gemsg_start(struct ynl_sock *ys, __u32 id, __u16 flags,
 	return nlh;
 }
 
-void ynl_msg_start_req(struct ynl_sock *ys, __u32 id)
+struct nlmsghdr *ynl_msg_start_req(struct ynl_sock *ys, __u32 id)
 {
-	ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK);
+	return ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK);
 }
 
-void ynl_msg_start_dump(struct ynl_sock *ys, __u32 id)
+struct nlmsghdr *ynl_msg_start_dump(struct ynl_sock *ys, __u32 id)
 {
-	ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP);
+	return ynl_msg_start(ys, id, NLM_F_REQUEST | NLM_F_ACK | NLM_F_DUMP);
 }
 
 struct nlmsghdr *

tools/net/ynl/pyynl/ynl_gen_c.py

@@ -1710,7 +1710,10 @@ def _multi_parse(ri, struct, init_lines, local_vars):
         ri.cw.p(f'dst->{arg} = {arg};')
 
     if ri.fixed_hdr:
-        ri.cw.p('hdr = ynl_nlmsg_data_offset(nlh, sizeof(struct genlmsghdr));')
+        if ri.family.is_classic():
+            ri.cw.p('hdr = ynl_nlmsg_data(nlh);')
+        else:
+            ri.cw.p('hdr = ynl_nlmsg_data_offset(nlh, sizeof(struct genlmsghdr));')
         ri.cw.p(f"memcpy(&dst->_hdr, hdr, sizeof({ri.fixed_hdr}));")
     for anest in sorted(all_multi):
         aspec = struct[anest]
@@ -1857,7 +1860,10 @@ def print_req(ri):
     ri.cw.block_start()
     ri.cw.write_func_lvar(local_vars)
 
-    ri.cw.p(f"nlh = ynl_gemsg_start_req(ys, {ri.nl.get_family_id()}, {ri.op.enum_name}, 1);")
+    if ri.family.is_classic():
+        ri.cw.p(f"nlh = ynl_msg_start_req(ys, {ri.op.enum_name});")
+    else:
+        ri.cw.p(f"nlh = ynl_gemsg_start_req(ys, {ri.nl.get_family_id()}, {ri.op.enum_name}, 1);")
 
     ri.cw.p(f"ys->req_policy = &{ri.struct['request'].render_name}_nest;")
     if 'reply' in ri.op[ri.op_mode]:
@@ -1926,7 +1932,10 @@ def print_dump(ri):
     else:
         ri.cw.p(f'yds.rsp_cmd = {ri.op.rsp_value};')
     ri.cw.nl()
-    ri.cw.p(f"nlh = ynl_gemsg_start_dump(ys, {ri.nl.get_family_id()}, {ri.op.enum_name}, 1);")
+    if ri.family.is_classic():
+        ri.cw.p(f"nlh = ynl_msg_start_dump(ys, {ri.op.enum_name});")
+    else:
+        ri.cw.p(f"nlh = ynl_gemsg_start_dump(ys, {ri.nl.get_family_id()}, {ri.op.enum_name}, 1);")
 
     if ri.fixed_hdr:
         ri.cw.p("hdr_len = sizeof(req->_hdr);")
@@ -2736,7 +2745,9 @@ def render_user_family(family, cw, prototype):
     if family.is_classic():
         cw.p(f'.is_classic\t= true,')
         cw.p(f'.classic_id\t= {family.get("protonum")},')
-    if family.fixed_header:
+    if family.is_classic():
+        cw.p(f'.hdr_len\t= sizeof(struct {c_lower(family.fixed_header)}),')
+    elif family.fixed_header:
         cw.p(f'.hdr_len\t= sizeof(struct genlmsghdr) + sizeof(struct {c_lower(family.fixed_header)}),')
     else:
         cw.p('.hdr_len\t= sizeof(struct genlmsghdr),')