netlink: make nla_nest_start() add NLA_F_NESTED flag

Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
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,