tools: ynl: give up on libmnl for auto-ints

The temporary auto-int helpers are not really correct.
We can't treat signed and unsigned ints the same when
determining whether we need full 8B. I realized this
before sending the patch to add support in libmnl.
Unfortunately, that patch has not been merged,
so time to fix our local helpers. Use the mnl* name
for now, subsequent patches will address that.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-2-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -125,20 +125,47 @@ int ynl_exec_dump(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
 void ynl_error_unknown_notification(struct ynl_sock *ys, __u8 cmd);
 int ynl_error_parse(struct ynl_parse_arg *yarg, const char *msg);
 
-#ifndef MNL_HAS_AUTO_SCALARS
-static inline uint64_t mnl_attr_get_uint(const struct nlattr *attr)
+/* Attribute helpers */
+
+static inline __u64 mnl_attr_get_uint(const struct nlattr *attr)
+{
+	switch (mnl_attr_get_payload_len(attr)) {
+	case 4:
+		return mnl_attr_get_u32(attr);
+	case 8:
+		return mnl_attr_get_u64(attr);
+	default:
+		return 0;
+	}
+}
+
+static inline __s64 mnl_attr_get_sint(const struct nlattr *attr)
 {
-	if (mnl_attr_get_payload_len(attr) == 4)
+	switch (mnl_attr_get_payload_len(attr)) {
+	case 4:
 		return mnl_attr_get_u32(attr);
+	case 8:
 		return mnl_attr_get_u64(attr);
+	default:
+		return 0;
+	}
 }
 
 static inline void
-mnl_attr_put_uint(struct nlmsghdr *nlh, uint16_t type, uint64_t data)
+mnl_attr_put_uint(struct nlmsghdr *nlh, __u16 type, __u64 data)
 {
-	if ((uint32_t)data == (uint64_t)data)
-		return mnl_attr_put_u32(nlh, type, data);
-	return mnl_attr_put_u64(nlh, type, data);
+	if ((__u32)data == (__u64)data)
+		mnl_attr_put_u32(nlh, type, data);
+	else
+		mnl_attr_put_u64(nlh, type, data);
+}
+
+static inline void
+mnl_attr_put_sint(struct nlmsghdr *nlh, __u16 type, __s64 data)
+{
+	if ((__s32)data == (__s64)data)
+		mnl_attr_put_u32(nlh, type, data);
+	else
+		mnl_attr_put_u64(nlh, type, data);
 }
-#endif
 #endif