[dpdk-dev] [PATCH v3] app/testpmd: enable GTP header parse and Tx checksum offload

[Ting Xu <ting.xu@intel.com>]

This patch enables testpmd to forward GTP packet in csum fwd mode.
GTP header structure (without optional fields and extension header)
and parser function are added. GTPU and GTPC packets are both
supported, with respective UDP destination port and GTP message
type.

Signed-off-by: Ting Xu <ting.xu@intel.com>

---
v3: correct coding style issue.
v2: modify commit log
depend on patch: lib/mbuf: add GTP tunnel type flag.
---
 app/test-pmd/csumonly.c | 115 ++++++++++++++++++++++++++++++++++++----
 1 file changed, 104 insertions(+), 11 deletions(-)

diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c
index e1cb7fb70..b7ff7c742 100644
--- a/app/test-pmd/csumonly.c
+++ b/app/test-pmd/csumonly.c
@@ -179,6 +179,84 @@ parse_ethernet(struct rte_ether_hdr *eth_hdr, struct testpmd_offload_info *info)
 	}
 }
 
+/*
+ * Parse a GTP protocol header.
+ * No optional fields and next extension header type.
+ */
+struct rte_gtp_hdr {
+	uint8_t gtp_hdr_info;
+	uint8_t msg_type;
+	uint16_t msg_len;
+	uint32_t teid;
+} __attribute__((__packed__));
+
+/* GTP header length */
+#define RTE_ETHER_GTP_HLEN \
+	(sizeof(struct rte_udp_hdr) + sizeof(struct rte_gtp_hdr))
+/* GTP next protocal type */
+#define RTE_GTP_TYPE_IPV4 0x40
+#define RTE_GTP_TYPE_IPV6 0x60
+
+static void
+parse_gtp(struct rte_udp_hdr *udp_hdr,
+	  struct testpmd_offload_info *info)
+{
+	struct rte_ipv4_hdr *ipv4_hdr;
+	struct rte_ipv6_hdr *ipv6_hdr;
+	struct rte_gtp_hdr *gtp_hdr;
+	uint8_t gtp_len = sizeof(*gtp_hdr);
+	uint8_t ip_ver;
+	/* GTP destination port number */
+	uint16_t gtpc_udp_port = 2123;
+	uint16_t gtpu_udp_port = 2152;
+
+	/* Check udp destination port. */
+	if (udp_hdr->dst_port != _htons(gtpc_udp_port) &&
+	    udp_hdr->src_port != _htons(gtpc_udp_port) &&
+	    udp_hdr->dst_port != _htons(gtpu_udp_port))
+		return;
+
+	info->is_tunnel = 1;
+	info->outer_ethertype = info->ethertype;
+	info->outer_l2_len = info->l2_len;
+	info->outer_l3_len = info->l3_len;
+	info->outer_l4_proto = info->l4_proto;
+	info->l2_len = 0;
+
+	gtp_hdr = (struct rte_gtp_hdr *)((char *)udp_hdr +
+		  sizeof(struct rte_udp_hdr));
+
+	/*
+	 * Check message type. If message type is 0xff, it is
+	 * a GTP data packet. If not, it is a GTP control packet
+	 */
+	if (gtp_hdr->msg_type == 0xff) {
+		ip_ver = *(uint8_t *)((char *)udp_hdr +
+			 sizeof(struct rte_udp_hdr) +
+			 sizeof(struct rte_gtp_hdr));
+		ip_ver = (ip_ver) & 0xf0;
+
+		if (ip_ver == RTE_GTP_TYPE_IPV4) {
+			ipv4_hdr = (struct rte_ipv4_hdr *)((char *)gtp_hdr +
+				   gtp_len);
+			info->ethertype = _htons(RTE_ETHER_TYPE_IPV4);
+			parse_ipv4(ipv4_hdr, info);
+		} else if (ip_ver == RTE_GTP_TYPE_IPV6) {
+			ipv6_hdr = (struct rte_ipv6_hdr *)((char *)gtp_hdr +
+				   gtp_len);
+			info->ethertype = _htons(RTE_ETHER_TYPE_IPV6);
+			parse_ipv6(ipv6_hdr, info);
+		}
+	} else {
+		info->ethertype = 0;
+		info->l4_len = 0;
+		info->l3_len = 0;
+		info->l4_proto = 0;
+	}
+
+	info->l2_len += RTE_ETHER_GTP_HLEN;
+}
+
 /* Parse a vxlan header */
 static void
 parse_vxlan(struct rte_udp_hdr *udp_hdr,
@@ -473,20 +551,27 @@ process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info *info,
 		else
 			ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
 	} else
-		ol_flags |= PKT_TX_OUTER_IPV6;
+		ol_flags |= (PKT_TX_OUTER_IPV6 | PKT_TX_OUTER_IP_CKSUM);
 
 	if (info->outer_l4_proto != IPPROTO_UDP)
 		return ol_flags;
 
+	udp_hdr = (struct rte_udp_hdr *)
+		((char *)outer_l3_hdr + info->outer_l3_len);
+
 	/* Skip SW outer UDP checksum generation if HW supports it */
 	if (tx_offloads & DEV_TX_OFFLOAD_OUTER_UDP_CKSUM) {
+		if (info->outer_ethertype == _htons(RTE_ETHER_TYPE_IPV4))
+			udp_hdr->dgram_cksum
+				= rte_ipv4_phdr_cksum(ipv4_hdr, ol_flags);
+		else
+			udp_hdr->dgram_cksum
+				= rte_ipv6_phdr_cksum(ipv6_hdr, ol_flags);
+
 		ol_flags |= PKT_TX_OUTER_UDP_CKSUM;
 		return ol_flags;
 	}
 
-	udp_hdr = (struct rte_udp_hdr *)
-		((char *)outer_l3_hdr + info->outer_l3_len);
-
 	/* outer UDP checksum is done in software. In the other side, for
 	 * UDP tunneling, like VXLAN or Geneve, outer UDP checksum can be
 	 * set to zero.
@@ -679,6 +764,7 @@ pkt_copy_split(const struct rte_mbuf *pkt)
  *           UDP|TCP|SCTP
  *   Ether / (vlan) / outer IP|IP6 / outer UDP / VXLAN-GPE / IP|IP6 /
  *           UDP|TCP|SCTP
+ *   Ether / (vlan) / outer IP / outer UDP / GTP / IP|IP6 / UDP|TCP|SCTP
  *   Ether / (vlan) / outer IP|IP6 / GRE / Ether / IP|IP6 / UDP|TCP|SCTP
  *   Ether / (vlan) / outer IP|IP6 / GRE / IP|IP6 / UDP|TCP|SCTP
  *   Ether / (vlan) / outer IP|IP6 / IP|IP6 / UDP|TCP|SCTP
@@ -787,16 +873,22 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 
 				udp_hdr = (struct rte_udp_hdr *)
 					((char *)l3_hdr + info.l3_len);
+				parse_gtp(udp_hdr, &info);
+				if (info.is_tunnel) {
+					tx_ol_flags |= PKT_TX_TUNNEL_GTP;
+					goto tunnel_update;
+				}
 				parse_vxlan_gpe(udp_hdr, &info);
 				if (info.is_tunnel) {
-					tx_ol_flags |= PKT_TX_TUNNEL_VXLAN_GPE;
-				} else {
-					parse_vxlan(udp_hdr, &info,
-						    m->packet_type);
-					if (info.is_tunnel)
-						tx_ol_flags |=
-							PKT_TX_TUNNEL_VXLAN;
+					tx_ol_flags |=
+						PKT_TX_TUNNEL_VXLAN_GPE;
+					goto tunnel_update;
 				}
+				parse_vxlan(udp_hdr, &info,
+					    m->packet_type);
+				if (info.is_tunnel)
+					tx_ol_flags |=
+					PKT_TX_TUNNEL_VXLAN;
 			} else if (info.l4_proto == IPPROTO_GRE) {
 				struct simple_gre_hdr *gre_hdr;
 
@@ -815,6 +907,7 @@ pkt_burst_checksum_forward(struct fwd_stream *fs)
 			}
 		}
 
+tunnel_update:
 		/* update l3_hdr and outer_l3_hdr if a tunnel was parsed */
 		if (info.is_tunnel) {
 			outer_l3_hdr = l3_hdr;
-- 
2.17.1