lib: add new stream function to reorganize buffer

The function was originally implemented for zebra data plane FPM plugin,
but another code places could use it.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

3 files changed, 26 insertions, 25 deletions

diff --git a/lib/stream.c b/lib/stream.c
index dc207c16a..e4e37b731 100644
--- a/lib/stream.c
+++ b/lib/stream.c
@@ -1372,3 +1372,19 @@ void stream_fifo_free(struct stream_fifo *fifo)
 	stream_fifo_deinit(fifo);
 	XFREE(MTYPE_STREAM_FIFO, fifo);
 }
+
+void stream_pulldown(struct stream *s)
+{
+	size_t rlen = STREAM_READABLE(s);
+
+	/* No more data, so just move the pointers. */
+	if (rlen == 0) {
+		stream_reset(s);
+		return;
+	}
+
+	/* Move the available data to the beginning. */
+	memmove(s->data, &s->data[s->getp], rlen);
+	s->getp = 0;
+	s->endp = rlen;
+}
diff --git a/lib/stream.h b/lib/stream.h
index 4f75f121c..dedbf3798 100644
--- a/lib/stream.h
+++ b/lib/stream.h
@@ -262,6 +262,16 @@ extern int stream_empty(struct stream *); /* is the stream empty? */
 /* debugging */
 extern void stream_hexdump(const struct stream *s);
 
+/**
+ * Reorganize the buffer data so it can fit more. This function is normally
+ * called right after stream data is consumed so we can read more data
+ * (the functions that consume data start with `stream_get*()` and macros
+ * `STREAM_GET*()`).
+ *
+ * \param s stream pointer.
+ */
+extern void stream_pulldown(struct stream *s);
+
 /* deprecated */
 extern uint8_t *stream_pnt(struct stream *);
 
diff --git a/zebra/dplane_fpm_nl.c b/zebra/dplane_fpm_nl.c
index 5bf47580a..fd214cad2 100644
--- a/zebra/dplane_fpm_nl.c
+++ b/zebra/dplane_fpm_nl.c
@@ -184,31 +184,6 @@ static int fpm_rmac_send(struct thread *t);
 static int fpm_rmac_reset(struct thread *t);
 
 /*
- * Helper functions.
- */
-
-/**
- * Reorganizes the data on the buffer so it can fit more data.
- *
- * @param s stream pointer.
- */
-static void stream_pulldown(struct stream *s)
-{
-	size_t rlen = STREAM_READABLE(s);
-
-	/* No more data, so just move the pointers. */
-	if (rlen == 0) {
-		stream_reset(s);
-		return;
-	}
-
-	/* Move the available data to the beginning. */
-	memmove(s->data, &s->data[s->getp], rlen);
-	s->getp = 0;
-	s->endp = rlen;
-}
-
-/*
  * CLI.
  */
 #define FPM_STR "Forwarding Plane Manager configuration\n"