blobmsg: allow data/length iterator/accessor functions to work on non-blobmsg elements

This primarily helps with simplifying the ubus APIs.
blobmsg header presence is indicated by the BLOB_ATTR_EXTENDED bit in
the id_len field.

This changes the format ABI, but not the API.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

1 files changed, 2 insertions, 3 deletions

diff --git a/blob.c b/blob.c
index faa3bb8..2da7cac 100644
--- a/blob.c
+++ b/blob.c
@@ -115,10 +115,9 @@ blob_fill_pad(struct blob_attr *attr)
 void
 blob_set_raw_len(struct blob_attr *attr, unsigned int len)
 {
-	int id = blob_id(attr);
 	len &= BLOB_ATTR_LEN_MASK;
-	len |= (id << BLOB_ATTR_ID_SHIFT) & BLOB_ATTR_ID_MASK;
-	attr->id_len = cpu_to_be32(len);
+	attr->id_len &= ~cpu_to_be32(BLOB_ATTR_LEN_MASK);
+	attr->id_len |= cpu_to_be32(len);
 }
 
 struct blob_attr *