net: add IPv6 header extension parsing function

Introduce new function for IPv6 header extension parsing able to
determine extension length and next protocol number.

This function is helpful when implementing IPv6 header traversing.

Signed-off-by: Marcin Smoczynski <marcinx.smoczynski@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Akhil Goyal <akhil.goyal@nxp.com>
Tested-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

diff --git a/lib/librte_net/rte_ip.h b/lib/librte_net/rte_ip.h
index 26b089e..4465073 100644 (file)
--- a/lib/librte_net/rte_ip.h
+++ b/lib/librte_net/rte_ip.h
@@ -440,6 +440,56 @@ rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
        return (uint16_t)cksum;
 }
 
+/* IPv6 fragmentation header size */
+#define RTE_IPV6_FRAG_HDR_SIZE 8
+
+/**
+ * Parse next IPv6 header extension
+ *
+ * This function checks if proto number is an IPv6 extensions and parses its
+ * data if so, providing information on next header and extension length.
+ *
+ * @param p
+ *   Pointer to an extension raw data.
+ * @param proto
+ *   Protocol number extracted from the "next header" field from
+ *   the IPv6 header or the previous extension.
+ * @param ext_len
+ *   Extension data length.
+ * @return
+ *   next protocol number if proto is an IPv6 extension, -EINVAL otherwise
+ */
+__rte_experimental
+static inline int
+rte_ipv6_get_next_ext(uint8_t *p, int proto, size_t *ext_len)
+{
+       int next_proto;
+
+       switch (proto) {
+       case IPPROTO_AH:
+               next_proto = *p++;
+               *ext_len = (*p + 2) * sizeof(uint32_t);
+               break;
+
+       case IPPROTO_HOPOPTS:
+       case IPPROTO_ROUTING:
+       case IPPROTO_DSTOPTS:
+               next_proto = *p++;
+               *ext_len = (*p + 1) * sizeof(uint64_t);
+               break;
+
+       case IPPROTO_FRAGMENT:
+               next_proto = *p;
+               *ext_len = RTE_IPV6_FRAG_HDR_SIZE;
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       return next_proto;
+}
+
 #ifdef __cplusplus
 }
 #endif