From 54d8b34ae46f21d51ab2507273edb7cc261f3cf4 Mon Sep 17 00:00:00 2001
From: adrian <adrian@FreeBSD.org>
Date: Thu, 30 Mar 2017 02:34:21 +0000
Subject: [PATCH] [mbufq] add a concat method.

Reviewed by:	gnn, ae, glebius
Approved by:	ae, glebius
Differential Revision:	https://reviews.freebsd.org/D10158
---
 sys/sys/mbuf.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index ecc5c2a9aab2..0dce057c3e66 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -1320,5 +1320,18 @@ mbufq_prepend(struct mbufq *mq, struct mbuf *m)
 	STAILQ_INSERT_HEAD(&mq->mq_head, m, m_stailqpkt);
 	mq->mq_len++;
 }
+
+/*
+ * Note: this doesn't enforce the maximum list size for dst.
+ */
+static inline void
+mbufq_concat(struct mbufq *mq_dst, struct mbufq *mq_src)
+{
+
+	mq_dst->mq_len += mq_src->mq_len;
+	STAILQ_CONCAT(&mq_dst->mq_head, &mq_src->mq_head);
+	mq_src->mq_len = 0;
+}
+
 #endif /* _KERNEL */
 #endif /* !_SYS_MBUF_H_ */