kni: add build-time checks for mbuf mapping

Adding this check is to avoid breakage from future data structure changes.

Signed-off-by: Jia Yu <jyu@vmware.com>
Acked-by: Thomas Monjalon <thomas.monjalon@6wind.com>

diff --git a/lib/librte_kni/rte_kni.c b/lib/librte_kni/rte_kni.c
index ab5ca38..fdb7509 100644 (file)
--- a/lib/librte_kni/rte_kni.c
+++ b/lib/librte_kni/rte_kni.c
@@ -595,6 +595,21 @@ kni_allocate_mbufs(struct rte_kni *kni)
        int i, ret;
        struct rte_mbuf *pkts[MAX_MBUF_BURST_NUM];
 
+       RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, pool) !=
+                        offsetof(struct rte_kni_mbuf, pool));
+       RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, buf_addr) !=
+                        offsetof(struct rte_kni_mbuf, buf_addr));
+       RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, next) !=
+                        offsetof(struct rte_kni_mbuf, next));
+       RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, data_off) !=
+                        offsetof(struct rte_kni_mbuf, data_off));
+       RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, data_len) !=
+                        offsetof(struct rte_kni_mbuf, data_len));
+       RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, pkt_len) !=
+                        offsetof(struct rte_kni_mbuf, pkt_len));
+       RTE_BUILD_BUG_ON(offsetof(struct rte_mbuf, ol_flags) !=
+                        offsetof(struct rte_kni_mbuf, ol_flags));
+
        /* Check if pktmbuf pool has been configured */
        if (kni->pktmbuf_pool == NULL) {
                RTE_LOG(ERR, KNI, "No valid mempool for allocating mbufs\n");