[dpdk-dev] [PATCH v2 3/4] examples/ipsec-secgw: add support for ipv6 options

[Marcin Smoczynski <marcinx.smoczynski@intel.com>]

Using transport with IPv6 and header extensions requires calculating
total header length including extensions up to ESP header which is
achieved with iteratively parsing extensions when preparing traffic
for processing. Calculated l3_len is later used to determine SPI
field offset for an inbound traffic and to reconstruct L3 header by
librte_ipsec.

Signed-off-by: Marcin Smoczynski <marcinx.smoczynski@intel.com>
---
 examples/ipsec-secgw/ipsec-secgw.c | 35 +++++++++++++++++++++++++-----
 examples/ipsec-secgw/sa.c          |  5 +----
 2 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/examples/ipsec-secgw/ipsec-secgw.c b/examples/ipsec-secgw/ipsec-secgw.c
index 6c626fa5f..17012caf9 100644
--- a/examples/ipsec-secgw/ipsec-secgw.c
+++ b/examples/ipsec-secgw/ipsec-secgw.c
@@ -41,6 +41,7 @@
 #include <rte_jhash.h>
 #include <rte_cryptodev.h>
 #include <rte_security.h>
+#include <rte_ip.h>
 
 #include "ipsec.h"
 #include "parser.h"
@@ -248,16 +249,40 @@ prepare_one_packet(struct rte_mbuf *pkt, struct ipsec_traffic *t)
 		pkt->l2_len = 0;
 		pkt->l3_len = sizeof(struct ip);
 	} else if (eth->ether_type == rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV6)) {
-		nlp = (uint8_t *)rte_pktmbuf_adj(pkt, RTE_ETHER_HDR_LEN);
-		nlp = RTE_PTR_ADD(nlp, offsetof(struct ip6_hdr, ip6_nxt));
-		if (*nlp == IPPROTO_ESP)
+		int next_proto;
+		size_t l3len, ext_len;
+		struct rte_ipv6_hdr *v6h;
+		uint8_t *p;
+
+		/* get protocol type */
+		v6h = (struct rte_ipv6_hdr *)rte_pktmbuf_adj(pkt,
+			RTE_ETHER_HDR_LEN);
+		next_proto = v6h->proto;
+
+		/* determine l3 header size up to ESP extension */
+		l3len = sizeof(struct ip6_hdr);
+		p = rte_pktmbuf_mtod(pkt, uint8_t *);
+		while (next_proto != IPPROTO_ESP && l3len < pkt->data_len &&
+			(next_proto = rte_ipv6_get_next_ext(p + l3len,
+						next_proto, &ext_len)) >= 0)
+			l3len += ext_len;
+
+		/* drop packet when IPv6 header exceeds first segment length */
+		if (unlikely(l3len > pkt->data_len)) {
+			rte_pktmbuf_free(pkt);
+			return;
+		}
+
+		if (next_proto == IPPROTO_ESP)
 			t->ipsec.pkts[(t->ipsec.num)++] = pkt;
 		else {
-			t->ip6.data[t->ip6.num] = nlp;
+			t->ip6.data[t->ip6.num] = rte_pktmbuf_mtod_offset(pkt,
+				uint8_t *,
+				offsetof(struct rte_ipv6_hdr, proto));
 			t->ip6.pkts[(t->ip6.num)++] = pkt;
 		}
 		pkt->l2_len = 0;
-		pkt->l3_len = sizeof(struct ip6_hdr);
+		pkt->l3_len = l3len;
 	} else {
 		/* Unknown/Unsupported type, drop the packet */
 		RTE_LOG(ERR, IPSEC, "Unsupported packet type 0x%x\n",
diff --git a/examples/ipsec-secgw/sa.c b/examples/ipsec-secgw/sa.c
index 8d47d1def..7262ccee8 100644
--- a/examples/ipsec-secgw/sa.c
+++ b/examples/ipsec-secgw/sa.c
@@ -1228,10 +1228,7 @@ single_inbound_lookup(struct ipsec_sa *sadb, struct rte_mbuf *pkt,
 	*sa_ret = NULL;
 
 	ip = rte_pktmbuf_mtod(pkt, struct ip *);
-	if (ip->ip_v == IPVERSION)
-		esp = (struct rte_esp_hdr *)(ip + 1);
-	else
-		esp = (struct rte_esp_hdr *)(((struct ip6_hdr *)ip) + 1);
+	esp = rte_pktmbuf_mtod_offset(pkt, struct rte_esp_hdr *, pkt->l3_len);
 
 	if (esp->spi == INVALID_SPI)
 		return;
-- 
2.17.1