P2P: Provide mechanism for figuring out p2p_scan_ie() buffer need

The new function, p2p_scan_ie_buf_len(), can be used to figure out
how large a buffer needs to be allocated for p2p_scan_ie() use. This
makes it easier to add new data into the buffer without forcing all
callers to be updated to use a larger buffer.

2 files changed, 13 insertions, 0 deletions

diff --git a/src/p2p/p2p.c b/src/p2p/p2p.c
index 816196a..3cb8f4d 100644
--- a/src/p2p/p2p.c
+++ b/src/p2p/p2p.c
@@ -2462,6 +2462,12 @@ void p2p_scan_ie(struct p2p_data *p2p, struct wpabuf *ies)
 }
 
 
+size_t p2p_scan_ie_buf_len(struct p2p_data *p2p)
+{
+	return 100;
+}
+
+
 int p2p_ie_text(struct wpabuf *p2p_ie, char *buf, char *end)
 {
 	return p2p_attr_text(p2p_ie, buf, end);
diff --git a/src/p2p/p2p.h b/src/p2p/p2p.h
index 4cab3da..31e83d5 100644
--- a/src/p2p/p2p.h
+++ b/src/p2p/p2p.h
@@ -1344,6 +1344,13 @@ int p2p_assoc_req_ie(struct p2p_data *p2p, const u8 *bssid, u8 *buf,
 void p2p_scan_ie(struct p2p_data *p2p, struct wpabuf *ies);
 
 /**
+ * p2p_scan_ie_buf_len - Get maximum buffer length needed for p2p_scan_ie
+ * @p2p: P2P module context from p2p_init()
+ * Returns: Number of octets that p2p_scan_ie() may add to the buffer
+ */
+size_t p2p_scan_ie_buf_len(struct p2p_data *p2p);
+
+/**
  * p2p_go_params - Generate random P2P group parameters
  * @p2p: P2P module context from p2p_init()
  * @params: Buffer for parameters