[PATCH dpdk v2 16/16] ipv6: add function to check ipv6 version

[Robin Jarry <rjarry@redhat.com>]

This is a slow path version to verify the version field in IPv6 headers.

Signed-off-by: Robin Jarry <rjarry@redhat.com>
---

Notes:
    v2: new patch

 app/test/test_net_ipv6.c | 16 ++++++++++++++++
 lib/net/rte_ip6.h        | 17 +++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/app/test/test_net_ipv6.c b/app/test/test_net_ipv6.c
index b087b5c60d73..79a43a2b5491 100644
--- a/app/test/test_net_ipv6.c
+++ b/app/test/test_net_ipv6.c
@@ -11,6 +11,21 @@ static const struct rte_ipv6_addr bcast_addr = {
 };
 static const struct rte_ipv6_addr zero_addr = { 0 };
 
+static int
+test_ipv6_check_version(void)
+{
+	struct rte_ipv6_hdr h;
+
+	h.vtc_flow = 0;
+	TEST_ASSERT_EQUAL(rte_ipv6_check_version(&h), -EINVAL, "");
+	h.vtc_flow = RTE_BE32(0x7f00ba44);
+	TEST_ASSERT_EQUAL(rte_ipv6_check_version(&h), -EINVAL, "");
+	h.vtc_flow = RTE_BE32(0x6badcaca);
+	TEST_ASSERT_EQUAL(rte_ipv6_check_version(&h), 0, "");
+
+	return 0;
+}
+
 static int
 test_ipv6_addr_mask(void)
 {
@@ -191,6 +206,7 @@ test_ether_mcast_from_ipv6(void)
 static int
 test_net_ipv6(void)
 {
+	TEST_ASSERT_SUCCESS(test_ipv6_check_version(), "");
 	TEST_ASSERT_SUCCESS(test_ipv6_addr_mask(), "");
 	TEST_ASSERT_SUCCESS(test_ipv6_addr_eq_prefix(), "");
 	TEST_ASSERT_SUCCESS(test_ipv6_addr_kind(), "");
diff --git a/lib/net/rte_ip6.h b/lib/net/rte_ip6.h
index c552fa54c095..de3ddc0348c5 100644
--- a/lib/net/rte_ip6.h
+++ b/lib/net/rte_ip6.h
@@ -323,6 +323,23 @@ struct rte_ipv6_hdr {
 	struct rte_ipv6_addr dst_addr;	/**< IP address of destination host(s). */
 } __rte_packed;
 
+#define RTE_IPV6_VTC_FLOW_VERSION RTE_BE32(0x60000000)
+#define RTE_IPV6_VTC_FLOW_VERSION_MASK RTE_BE32(0xf0000000)
+
+/**
+ * Check that the IPv6 header version field is valid according to RFC 8200 section 3.
+ *
+ * @return
+ *   0 if the version field is valid. -EINVAL otherwise.
+ */
+static inline int rte_ipv6_check_version(const struct rte_ipv6_hdr *ip)
+{
+	rte_be32_t v = ip->vtc_flow & RTE_IPV6_VTC_FLOW_VERSION_MASK;
+	if (v != RTE_IPV6_VTC_FLOW_VERSION)
+		return -EINVAL;
+	return 0;
+}
+
 /* IPv6 routing extension type definition. */
 #define RTE_IPV6_SRCRT_TYPE_4 4
 
-- 
2.46.1