[PATCH 1/2] net: fixup RARP generation

[Yuanhan Liu <yliu@fridaylinux.org>]

Due to a mistake operation from me, older version (v10) was merged to
master branch. It's the v11 should be applied. However, the master branch
is not rebase-able. Thus, this patch is made, from the diff between v10
and v11.

Code is from Xiao Wang.

Signed-off-by: Yuanhan Liu <yliu@fridaylinux.org>
---
 lib/librte_net/rte_arp.c      | 26 +++++++++++++++++---------
 lib/librte_net/rte_arp.h      | 11 ++++++-----
 lib/librte_vhost/virtio_net.c | 12 +++---------
 3 files changed, 26 insertions(+), 23 deletions(-)

diff --git a/lib/librte_net/rte_arp.c b/lib/librte_net/rte_arp.c
index d7223b0..b953bcd 100644
--- a/lib/librte_net/rte_arp.c
+++ b/lib/librte_net/rte_arp.c
@@ -7,17 +7,28 @@
 #include <rte_arp.h>
 
 #define RARP_PKT_SIZE	64
-int
-rte_net_make_rarp_packet(struct rte_mbuf *mbuf, const struct ether_addr *mac)
+struct rte_mbuf *
+rte_net_make_rarp_packet(struct rte_mempool *mpool,
+		const struct ether_addr *mac)
 {
 	struct ether_hdr *eth_hdr;
 	struct arp_hdr *rarp;
+	struct rte_mbuf *mbuf;
 
-	if (mbuf->buf_len < RARP_PKT_SIZE)
-		return -1;
+	if (mpool == NULL)
+		return NULL;
+
+	mbuf = rte_pktmbuf_alloc(mpool);
+	if (mbuf == NULL)
+		return NULL;
+
+	eth_hdr = (struct ether_hdr *)rte_pktmbuf_append(mbuf, RARP_PKT_SIZE);
+	if (eth_hdr == NULL) {
+		rte_pktmbuf_free(mbuf);
+		return NULL;
+	}
 
 	/* Ethernet header. */
-	eth_hdr = rte_pktmbuf_mtod(mbuf, struct ether_hdr *);
 	memset(eth_hdr->d_addr.addr_bytes, 0xff, ETHER_ADDR_LEN);
 	ether_addr_copy(mac, &eth_hdr->s_addr);
 	eth_hdr->ether_type = htons(ETHER_TYPE_RARP);
@@ -35,8 +46,5 @@ rte_net_make_rarp_packet(struct rte_mbuf *mbuf, const struct ether_addr *mac)
 	memset(&rarp->arp_data.arp_sip, 0x00, 4);
 	memset(&rarp->arp_data.arp_tip, 0x00, 4);
 
-	mbuf->data_len = RARP_PKT_SIZE;
-	mbuf->pkt_len = RARP_PKT_SIZE;
-
-	return 0;
+	return mbuf;
 }
diff --git a/lib/librte_net/rte_arp.h b/lib/librte_net/rte_arp.h
index dad7423..457a39b 100644
--- a/lib/librte_net/rte_arp.h
+++ b/lib/librte_net/rte_arp.h
@@ -82,16 +82,17 @@ struct arp_hdr {
  *
  * Make a RARP packet based on MAC addr.
  *
- * @param mbuf
- *   Pointer to the rte_mbuf structure
+ * @param mpool
+ *   Pointer to the rte_mempool
  * @param mac
  *   Pointer to the MAC addr
  *
  * @return
- *   - 0 on success, negative on error
+ *   - RARP packet pointer on success, or NULL on error
  */
-int
-rte_net_make_rarp_packet(struct rte_mbuf *mbuf, const struct ether_addr *mac);
+struct rte_mbuf *
+rte_net_make_rarp_packet(struct rte_mempool *mpool,
+		const struct ether_addr *mac);
 
 #ifdef __cplusplus
 }
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index ca89288..a1d8026 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1162,19 +1162,13 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
 			rte_atomic16_cmpset((volatile uint16_t *)
 				&dev->broadcast_rarp.cnt, 1, 0))) {
 
-		rarp_mbuf = rte_pktmbuf_alloc(mbuf_pool);
+		rarp_mbuf = rte_net_make_rarp_packet(mbuf_pool, &dev->mac);
 		if (rarp_mbuf == NULL) {
 			RTE_LOG(ERR, VHOST_DATA,
-				"Failed to allocate memory for mbuf.\n");
+				"Failed to make RARP packet.\n");
 			return 0;
 		}
-
-		if (rte_net_make_rarp_packet(rarp_mbuf, &dev->mac) < 0) {
-			rte_pktmbuf_free(rarp_mbuf);
-			rarp_mbuf = NULL;
-		} else {
-			count -= 1;
-		}
+		count -= 1;
 	}
 
 	free_entries = *((volatile uint16_t *)&vq->avail->idx) -
-- 
2.7.4