Merge branch 'nla_nest_start'

Michal Kubecek says:

====================
make nla_nest_start() add NLA_F_NESTED flag

One of the comments in recent review of the ethtool netlink series pointed
out that proposed ethnl_nest_start() helper which adds NLA_F_NESTED to
second argument of nla_nest_start() is not really specific to ethtool
netlink code. That is hard to argue with as closer inspection revealed that
exactly the same helper already exists in ipset code (except it's a macro
rather than an inline function).

Another observation was that even if NLA_F_NESTED flag was introduced in
2007, only few netlink based interfaces set it in kernel generated messages
and even many recently added APIs omit it. That is unfortunate as without
the flag, message parsers not familiar with attribute semantics cannot
recognize nested attributes and do not see message structure; this affects
e.g. wireshark dissector or mnl_nlmsg_fprintf() from libmnl.

This is why I'm suggesting to rename existing nla_nest_start() to different
name (nla_nest_start_noflag) and reintroduce nla_nest_start() as a wrapper
adding NLA_F_NESTED flag. This is implemented in first patch which is
mostly generated by spatch. Second patch drops ipset helper macros which
lose their purpose. Third patch cleans up minor coding style issues found
by checkpatch.pl in first patch.

We could leave nla_nest_start() untouched and simply add a wrapper adding
NLA_F_NESTED but that would probably preserve the state when even most new
code doesn't set the flag.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 44 insertions, 34 deletions

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 7b91605e75d6..b94f326f5f06 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -1671,7 +1671,7 @@ int devlink_dpipe_match_put(struct sk_buff *skb,
 	struct devlink_dpipe_field *field = &header->fields[match->field_id];
 	struct nlattr *match_attr;
 
-	match_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_MATCH);
+	match_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_DPIPE_MATCH);
 	if (!match_attr)
 		return -EMSGSIZE;
 
@@ -1696,7 +1696,8 @@ static int devlink_dpipe_matches_put(struct devlink_dpipe_table *table,
 {
 	struct nlattr *matches_attr;
 
-	matches_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_TABLE_MATCHES);
+	matches_attr = nla_nest_start_noflag(skb,
+					     DEVLINK_ATTR_DPIPE_TABLE_MATCHES);
 	if (!matches_attr)
 		return -EMSGSIZE;
 
@@ -1718,7 +1719,7 @@ int devlink_dpipe_action_put(struct sk_buff *skb,
 	struct devlink_dpipe_field *field = &header->fields[action->field_id];
 	struct nlattr *action_attr;
 
-	action_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_ACTION);
+	action_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_DPIPE_ACTION);
 	if (!action_attr)
 		return -EMSGSIZE;
 
@@ -1743,7 +1744,8 @@ static int devlink_dpipe_actions_put(struct devlink_dpipe_table *table,
 {
 	struct nlattr *actions_attr;
 
-	actions_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_TABLE_ACTIONS);
+	actions_attr = nla_nest_start_noflag(skb,
+					     DEVLINK_ATTR_DPIPE_TABLE_ACTIONS);
 	if (!actions_attr)
 		return -EMSGSIZE;
 
@@ -1765,7 +1767,7 @@ static int devlink_dpipe_table_put(struct sk_buff *skb,
 	u64 table_size;
 
 	table_size = table->table_ops->size_get(table->priv);
-	table_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_TABLE);
+	table_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_DPIPE_TABLE);
 	if (!table_attr)
 		return -EMSGSIZE;
 
@@ -1845,7 +1847,7 @@ start_again:
 
 	if (devlink_nl_put_handle(skb, devlink))
 		goto nla_put_failure;
-	tables_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_TABLES);
+	tables_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_DPIPE_TABLES);
 	if (!tables_attr)
 		goto nla_put_failure;
 
@@ -1946,8 +1948,8 @@ static int devlink_dpipe_action_values_put(struct sk_buff *skb,
 	int err;
 
 	for (i = 0; i < values_count; i++) {
-		action_attr = nla_nest_start(skb,
-					     DEVLINK_ATTR_DPIPE_ACTION_VALUE);
+		action_attr = nla_nest_start_noflag(skb,
+						    DEVLINK_ATTR_DPIPE_ACTION_VALUE);
 		if (!action_attr)
 			return -EMSGSIZE;
 		err = devlink_dpipe_action_value_put(skb, &values[i]);
@@ -1983,8 +1985,8 @@ static int devlink_dpipe_match_values_put(struct sk_buff *skb,
 	int err;
 
 	for (i = 0; i < values_count; i++) {
-		match_attr = nla_nest_start(skb,
-					    DEVLINK_ATTR_DPIPE_MATCH_VALUE);
+		match_attr = nla_nest_start_noflag(skb,
+						   DEVLINK_ATTR_DPIPE_MATCH_VALUE);
 		if (!match_attr)
 			return -EMSGSIZE;
 		err = devlink_dpipe_match_value_put(skb, &values[i]);
@@ -2005,7 +2007,7 @@ static int devlink_dpipe_entry_put(struct sk_buff *skb,
 	struct nlattr *entry_attr, *matches_attr, *actions_attr;
 	int err;
 
-	entry_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_ENTRY);
+	entry_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_DPIPE_ENTRY);
 	if (!entry_attr)
 		return  -EMSGSIZE;
 
@@ -2017,8 +2019,8 @@ static int devlink_dpipe_entry_put(struct sk_buff *skb,
 				      entry->counter, DEVLINK_ATTR_PAD))
 			goto nla_put_failure;
 
-	matches_attr = nla_nest_start(skb,
-				      DEVLINK_ATTR_DPIPE_ENTRY_MATCH_VALUES);
+	matches_attr = nla_nest_start_noflag(skb,
+					     DEVLINK_ATTR_DPIPE_ENTRY_MATCH_VALUES);
 	if (!matches_attr)
 		goto nla_put_failure;
 
@@ -2030,8 +2032,8 @@ static int devlink_dpipe_entry_put(struct sk_buff *skb,
 	}
 	nla_nest_end(skb, matches_attr);
 
-	actions_attr = nla_nest_start(skb,
-				      DEVLINK_ATTR_DPIPE_ENTRY_ACTION_VALUES);
+	actions_attr = nla_nest_start_noflag(skb,
+					     DEVLINK_ATTR_DPIPE_ENTRY_ACTION_VALUES);
 	if (!actions_attr)
 		goto nla_put_failure;
 
@@ -2088,8 +2090,8 @@ int devlink_dpipe_entry_ctx_prepare(struct devlink_dpipe_dump_ctx *dump_ctx)
 	devlink = dump_ctx->info->user_ptr[0];
 	if (devlink_nl_put_handle(dump_ctx->skb, devlink))
 		goto nla_put_failure;
-	dump_ctx->nest = nla_nest_start(dump_ctx->skb,
-					DEVLINK_ATTR_DPIPE_ENTRIES);
+	dump_ctx->nest = nla_nest_start_noflag(dump_ctx->skb,
+					       DEVLINK_ATTR_DPIPE_ENTRIES);
 	if (!dump_ctx->nest)
 		goto nla_put_failure;
 	return 0;
@@ -2199,7 +2201,8 @@ static int devlink_dpipe_fields_put(struct sk_buff *skb,
 
 	for (i = 0; i < header->fields_count; i++) {
 		field = &header->fields[i];
-		field_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_FIELD);
+		field_attr = nla_nest_start_noflag(skb,
+						   DEVLINK_ATTR_DPIPE_FIELD);
 		if (!field_attr)
 			return -EMSGSIZE;
 		if (nla_put_string(skb, DEVLINK_ATTR_DPIPE_FIELD_NAME, field->name) ||
@@ -2222,7 +2225,7 @@ static int devlink_dpipe_header_put(struct sk_buff *skb,
 	struct nlattr *fields_attr, *header_attr;
 	int err;
 
-	header_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_HEADER);
+	header_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_DPIPE_HEADER);
 	if (!header_attr)
 		return -EMSGSIZE;
 
@@ -2231,7 +2234,8 @@ static int devlink_dpipe_header_put(struct sk_buff *skb,
 	    nla_put_u8(skb, DEVLINK_ATTR_DPIPE_HEADER_GLOBAL, header->global))
 		goto nla_put_failure;
 
-	fields_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_HEADER_FIELDS);
+	fields_attr = nla_nest_start_noflag(skb,
+					    DEVLINK_ATTR_DPIPE_HEADER_FIELDS);
 	if (!fields_attr)
 		goto nla_put_failure;
 
@@ -2278,7 +2282,7 @@ start_again:
 
 	if (devlink_nl_put_handle(skb, devlink))
 		goto nla_put_failure;
-	headers_attr = nla_nest_start(skb, DEVLINK_ATTR_DPIPE_HEADERS);
+	headers_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_DPIPE_HEADERS);
 	if (!headers_attr)
 		goto nla_put_failure;
 
@@ -2502,7 +2506,7 @@ static int devlink_resource_put(struct devlink *devlink, struct sk_buff *skb,
 	struct nlattr *child_resource_attr;
 	struct nlattr *resource_attr;
 
-	resource_attr = nla_nest_start(skb, DEVLINK_ATTR_RESOURCE);
+	resource_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_RESOURCE);
 	if (!resource_attr)
 		return -EMSGSIZE;
 
@@ -2526,7 +2530,8 @@ static int devlink_resource_put(struct devlink *devlink, struct sk_buff *skb,
 		       resource->size_valid))
 		goto nla_put_failure;
 
-	child_resource_attr = nla_nest_start(skb, DEVLINK_ATTR_RESOURCE_LIST);
+	child_resource_attr = nla_nest_start_noflag(skb,
+						    DEVLINK_ATTR_RESOURCE_LIST);
 	if (!child_resource_attr)
 		goto nla_put_failure;
 
@@ -2577,7 +2582,8 @@ start_again:
 	if (devlink_nl_put_handle(skb, devlink))
 		goto nla_put_failure;
 
-	resources_attr = nla_nest_start(skb, DEVLINK_ATTR_RESOURCE_LIST);
+	resources_attr = nla_nest_start_noflag(skb,
+					       DEVLINK_ATTR_RESOURCE_LIST);
 	if (!resources_attr)
 		goto nla_put_failure;
 
@@ -2831,7 +2837,8 @@ devlink_nl_param_value_fill_one(struct sk_buff *msg,
 {
 	struct nlattr *param_value_attr;
 
-	param_value_attr = nla_nest_start(msg, DEVLINK_ATTR_PARAM_VALUE);
+	param_value_attr = nla_nest_start_noflag(msg,
+						 DEVLINK_ATTR_PARAM_VALUE);
 	if (!param_value_attr)
 		goto nla_put_failure;
 
@@ -2922,7 +2929,7 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
 		if (nla_put_u32(msg, DEVLINK_ATTR_PORT_INDEX, port_index))
 			goto genlmsg_cancel;
 
-	param_attr = nla_nest_start(msg, DEVLINK_ATTR_PARAM);
+	param_attr = nla_nest_start_noflag(msg, DEVLINK_ATTR_PARAM);
 	if (!param_attr)
 		goto genlmsg_cancel;
 	if (nla_put_string(msg, DEVLINK_ATTR_PARAM_NAME, param->name))
@@ -2936,7 +2943,8 @@ static int devlink_nl_param_fill(struct sk_buff *msg, struct devlink *devlink,
 	if (nla_put_u8(msg, DEVLINK_ATTR_PARAM_TYPE, nla_type))
 		goto param_nest_cancel;
 
-	param_values_list = nla_nest_start(msg, DEVLINK_ATTR_PARAM_VALUES_LIST);
+	param_values_list = nla_nest_start_noflag(msg,
+						  DEVLINK_ATTR_PARAM_VALUES_LIST);
 	if (!param_values_list)
 		goto param_nest_cancel;
 
@@ -3336,7 +3344,7 @@ static int devlink_nl_region_snapshot_id_put(struct sk_buff *msg,
 	struct nlattr *snap_attr;
 	int err;
 
-	snap_attr = nla_nest_start(msg, DEVLINK_ATTR_REGION_SNAPSHOT);
+	snap_attr = nla_nest_start_noflag(msg, DEVLINK_ATTR_REGION_SNAPSHOT);
 	if (!snap_attr)
 		return -EINVAL;
 
@@ -3360,7 +3368,8 @@ static int devlink_nl_region_snapshots_id_put(struct sk_buff *msg,
 	struct nlattr *snapshots_attr;
 	int err;
 
-	snapshots_attr = nla_nest_start(msg, DEVLINK_ATTR_REGION_SNAPSHOTS);
+	snapshots_attr = nla_nest_start_noflag(msg,
+					       DEVLINK_ATTR_REGION_SNAPSHOTS);
 	if (!snapshots_attr)
 		return -EINVAL;
 
@@ -3576,7 +3585,7 @@ static int devlink_nl_cmd_region_read_chunk_fill(struct sk_buff *msg,
 	struct nlattr *chunk_attr;
 	int err;
 
-	chunk_attr = nla_nest_start(msg, DEVLINK_ATTR_REGION_CHUNK);
+	chunk_attr = nla_nest_start_noflag(msg, DEVLINK_ATTR_REGION_CHUNK);
 	if (!chunk_attr)
 		return -EINVAL;
 
@@ -3709,7 +3718,7 @@ static int devlink_nl_cmd_region_read_dumpit(struct sk_buff *skb,
 	if (err)
 		goto nla_put_failure;
 
-	chunks_attr = nla_nest_start(skb, DEVLINK_ATTR_REGION_CHUNKS);
+	chunks_attr = nla_nest_start_noflag(skb, DEVLINK_ATTR_REGION_CHUNKS);
 	if (!chunks_attr) {
 		err = -EMSGSIZE;
 		goto nla_put_failure;
@@ -3785,7 +3794,7 @@ static int devlink_info_version_put(struct devlink_info_req *req, int attr,
 	struct nlattr *nest;
 	int err;
 
-	nest = nla_nest_start(req->msg, attr);
+	nest = nla_nest_start_noflag(req->msg, attr);
 	if (!nest)
 		return -EMSGSIZE;
 
@@ -4313,7 +4322,7 @@ devlink_fmsg_prepare_skb(struct devlink_fmsg *fmsg, struct sk_buff *skb,
 	int i = 0;
 	int err;
 
-	fmsg_nlattr = nla_nest_start(skb, DEVLINK_ATTR_FMSG);
+	fmsg_nlattr = nla_nest_start_noflag(skb, DEVLINK_ATTR_FMSG);
 	if (!fmsg_nlattr)
 		return -EMSGSIZE;
 
@@ -4665,7 +4674,8 @@ devlink_nl_health_reporter_fill(struct sk_buff *msg,
 	if (devlink_nl_put_handle(msg, devlink))
 		goto genlmsg_cancel;
 
-	reporter_attr = nla_nest_start(msg, DEVLINK_ATTR_HEALTH_REPORTER);
+	reporter_attr = nla_nest_start_noflag(msg,
+					      DEVLINK_ATTR_HEALTH_REPORTER);
 	if (!reporter_attr)
 		goto genlmsg_cancel;
 	if (nla_put_string(msg, DEVLINK_ATTR_HEALTH_REPORTER_NAME,