diff --git a/net/9p/protocol.h b/net/9p/protocol.h
index 2431c0f..a0eb8ff 100644
--- a/net/9p/protocol.h
+++ b/net/9p/protocol.h
@@ -32,3 +32,4 @@
 int p9pdu_finalize(struct p9_fcall *pdu);
 void p9pdu_dump(int, struct p9_fcall *);
 void p9pdu_reset(struct p9_fcall *pdu);
+size_t pdu_read(struct p9_fcall *pdu, void *data, size_t size);