1 files changed, 60 insertions, 0 deletions
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 75e6e032bb3a..dc71c6ac5bf5 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -2288,6 +2288,66 @@ out:
 	kfree(profile);
 }
 
+ssize_t cfg80211_defragment_element(const struct element *elem, const u8 *ies,
+				    size_t ieslen, u8 *data, size_t data_len,
+				    u8 frag_id)
+{
+	const struct element *next;
+	ssize_t copied;
+	u8 elem_datalen;
+
+	if (!elem)
+		return -EINVAL;
+
+	/* elem might be invalid after the memmove */
+	next = (void *)(elem->data + elem->datalen);
+
+	elem_datalen = elem->datalen;
+	if (elem->id == WLAN_EID_EXTENSION) {
+		copied = elem->datalen - 1;
+		if (copied > data_len)
+			return -ENOSPC;
+
+		memmove(data, elem->data + 1, copied);
+	} else {
+		copied = elem->datalen;
+		if (copied > data_len)
+			return -ENOSPC;
+
+		memmove(data, elem->data, copied);
+	}
+
+	/* Fragmented elements must have 255 bytes */
+	if (elem_datalen < 255)
+		return copied;
+
+	for (elem = next;
+	     elem->data < ies + ieslen &&
+		elem->data + elem->datalen < ies + ieslen;
+	     elem = next) {
+		/* elem might be invalid after the memmove */
+		next = (void *)(elem->data + elem->datalen);
+
+		if (elem->id != frag_id)
+			break;
+
+		elem_datalen = elem->datalen;
+
+		if (copied + elem_datalen > data_len)
+			return -ENOSPC;
+
+		memmove(data + copied, elem->data, elem_datalen);
+		copied += elem_datalen;
+
+		/* Only the last fragment may be short */
+		if (elem_datalen != 255)
+			break;
+	}
+
+	return copied;
+}
+EXPORT_SYMBOL(cfg80211_defragment_element);
+
 struct cfg80211_bss *
 cfg80211_inform_bss_data(struct wiphy *wiphy,
 			 struct cfg80211_inform_bss *data,