[dpdk-dev] [PATCH 1/2] mbuf: Add rte_pktmbuf_copy

[Stephen Hemminger <stephen@networkplumber.org>]

From: Stephen Hemminger <shemming@brocade.com>

Added rte_pktmbuf_copy() function since copying multi-part
segments is common issue and can be problematic.

Signed-off-by: Mike Davison <mdavison@brocade.com>
Reviewed-by: Stephen Hemminger <shemming@brocade.com>
---
 lib/librte_mbuf/rte_mbuf.h | 59 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)

diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
index 80419df..f0a543b 100644
--- a/lib/librte_mbuf/rte_mbuf.h
+++ b/lib/librte_mbuf/rte_mbuf.h
@@ -60,6 +60,7 @@
 #include <rte_atomic.h>
 #include <rte_prefetch.h>
 #include <rte_branch_prediction.h>
+#include <rte_memcpy.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -1272,6 +1273,64 @@ static inline int rte_pktmbuf_is_contiguous(const struct rte_mbuf *m)
 	return !!(m->nb_segs == 1);
 }
 
+/*
+ * Creates a copy of the given packet mbuf.
+ *
+ * Walks through all segments of the given packet mbuf, and for each of them:
+ *  - Creates a new packet mbuf from the given pool.
+ *  - Copy segment to newly created mbuf.
+ * Then updates pkt_len and nb_segs of the new packet mbuf to match values
+ * from the original packet mbuf.
+ *
+ * @param md
+ *   The packet mbuf to be copied.
+ * @param mp
+ *   The mempool from which the mbufs are allocated.
+ * @return
+ *   - The pointer to the new mbuf on success.
+ *   - NULL if allocation fails.
+ */
+static inline struct rte_mbuf *rte_pktmbuf_copy(struct rte_mbuf *md,
+		struct rte_mempool *mp)
+{
+	struct rte_mbuf *mc = NULL;
+	struct rte_mbuf **prev = &mc;
+
+	do {
+		struct rte_mbuf *mi;
+
+		mi = rte_pktmbuf_alloc(mp);
+		if (unlikely(mi == NULL)) {
+			rte_pktmbuf_free(mc);
+			return NULL;
+		}
+
+		mi->data_off = md->data_off;
+		mi->data_len = md->data_len;
+		mi->port = md->port;
+		mi->vlan_tci = md->vlan_tci;
+		mi->tx_offload = md->tx_offload;
+		mi->hash = md->hash;
+
+		mi->next = NULL;
+		mi->pkt_len = md->pkt_len;
+		mi->nb_segs = md->nb_segs;
+		mi->ol_flags = md->ol_flags;
+		mi->packet_type = md->packet_type;
+
+		rte_memcpy(rte_pktmbuf_mtod(mi, char *),
+			   rte_pktmbuf_mtod(md, char *),
+			   md->data_len);
+
+		*prev = mi;
+		prev = &mi->next;
+	} while ((md = md->next) != NULL);
+
+	*prev = NULL;
+	__rte_mbuf_sanity_check(mc, 1);
+	return mc;
+}
+
 /**
  * Dump an mbuf structure to the console.
  *
-- 
2.1.4