tools: ynl: switch away from mnl_cb_t

All YNL parsing callbacks take struct ynl_parse_arg as the argument.
Make that official by using a local callback type instead of mnl_cb_t.
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20240227223032.1835527-12-kuba@kernel.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -6,6 +6,8 @@
 #include <libmnl/libmnl.h>
 #include <linux/types.h>
 
+struct ynl_parse_arg;
+
 /*
  * YNL internals / low level stuff
  */
@@ -30,6 +32,9 @@ enum ynl_policy_type {
 #define YNL_ARRAY_SIZE(array)	(sizeof(array) ?			\
 				 sizeof(array) / sizeof(array[0]) : 0)
 
+typedef int (*ynl_parse_cb_t)(const struct nlmsghdr *nlh,
+			      struct ynl_parse_arg *yarg);
+
 struct ynl_policy_attr {
 	enum ynl_policy_type type;
 	unsigned int len;
@@ -94,7 +99,7 @@ int ynl_attr_validate(struct ynl_parse_arg *yarg, const struct nlattr *attr);
 
 struct ynl_req_state {
 	struct ynl_parse_arg yarg;
-	mnl_cb_t cb;
+	ynl_parse_cb_t cb;
 	__u32 rsp_cmd;
 };
 
@@ -103,13 +108,13 @@ struct ynl_dump_state {
 	void *first;
 	struct ynl_dump_list_type *last;
 	size_t alloc_sz;
-	mnl_cb_t cb;
+	ynl_parse_cb_t cb;
 	__u32 rsp_cmd;
 };
 
 struct ynl_ntf_info {
 	struct ynl_policy_nest *policy;
-	mnl_cb_t cb;
+	ynl_parse_cb_t cb;
 	size_t alloc_sz;
 	void (*free)(struct ynl_ntf_base_type *ntf);
 };

tools/net/ynl/lib/ynl.c

@@ -449,17 +449,15 @@ ynl_gemsg_start_dump(struct ynl_sock *ys, __u32 id, __u8 cmd, __u8 version)
 			       cmd, version);
 }
 
-static int ynl_cb_null(const struct nlmsghdr *nlh, void *data)
+static int ynl_cb_null(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg)
 {
-	struct ynl_parse_arg *yarg = data;
-
 	yerr(yarg->ys, YNL_ERROR_UNEXPECT_MSG,
 	     "Received a message when none were expected");
 
 	return MNL_CB_ERROR;
 }
 
-static int ynl_sock_read_msgs(struct ynl_parse_arg *yarg, mnl_cb_t cb)
+static int ynl_sock_read_msgs(struct ynl_parse_arg *yarg, ynl_parse_cb_t cb)
 {
 	struct ynl_sock *ys = yarg->ys;
 	const struct nlmsghdr *nlh;
@@ -558,9 +556,9 @@ ynl_get_family_info_mcast(struct ynl_sock *ys, const struct nlattr *mcasts)
 	return 0;
 }
 
-static int ynl_get_family_info_cb(const struct nlmsghdr *nlh, void *data)
+static int
+ynl_get_family_info_cb(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg)
 {
-	struct ynl_parse_arg *yarg = data;
 	struct ynl_sock *ys = yarg->ys;
 	const struct nlattr *attr;
 	bool found_id = true;
@@ -770,10 +768,9 @@ static int ynl_ntf_parse(struct ynl_sock *ys, const struct nlmsghdr *nlh)
 	return MNL_CB_ERROR;
 }
 
-static int ynl_ntf_trampoline(const struct nlmsghdr *nlh, void *data)
+static int
+ynl_ntf_trampoline(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg)
 {
-	struct ynl_parse_arg *yarg = data;
-
 	return ynl_ntf_parse(yarg->ys, nlh);
 }
 
@@ -836,9 +833,10 @@ ynl_check_alien(struct ynl_sock *ys, const struct nlmsghdr *nlh, __u32 rsp_cmd)
 	return 0;
 }
 
-static int ynl_req_trampoline(const struct nlmsghdr *nlh, void *data)
+static
+int ynl_req_trampoline(const struct nlmsghdr *nlh, struct ynl_parse_arg *yarg)
 {
-	struct ynl_req_state *yrs = data;
+	struct ynl_req_state *yrs = (void *)yarg;
 	int ret;
 
 	ret = ynl_check_alien(yrs->yarg.ys, nlh, yrs->rsp_cmd);
@@ -864,9 +862,10 @@ int ynl_exec(struct ynl_sock *ys, struct nlmsghdr *req_nlh,
 	return err;
 }
 
-static int ynl_dump_trampoline(const struct nlmsghdr *nlh, void *data)
+static int
+ynl_dump_trampoline(const struct nlmsghdr *nlh, struct ynl_parse_arg *data)
 {
-	struct ynl_dump_state *ds = data;
+	struct ynl_dump_state *ds = (void *)data;
 	struct ynl_dump_list_type *obj;
 	struct ynl_parse_arg yarg = {};
 	int ret;

tools/net/ynl/ynl-gen-c.py

@@ -1737,10 +1737,9 @@ def parse_rsp_msg(ri, deref=False):
         return
 
     func_args = ['const struct nlmsghdr *nlh',
-                 'void *data']
+                 'struct ynl_parse_arg *yarg']
 
     local_vars = [f'{type_name(ri, "reply", deref=deref)} *dst;',
-                  'struct ynl_parse_arg *yarg = data;',
                   'const struct nlattr *attr;']
     init_lines = ['dst = yarg->data;']