[dpdk-dev] [PATCH 07/10] examples/tep_termination:add Tx checksum offload configuration for inner header

[Jijiang Liu <jijiang.liu@intel.com>]

For VXLAN packet, the inner Tx checksum offload means inner IPv4 and inner L4(TCP/UDP/SCTP).

Signed-off-by: Jijiang Liu <jijiang.liu@intel.com>
---
 examples/tep_termination/main.c  |   17 ++++++++
 examples/tep_termination/vxlan.c |   80 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+), 0 deletions(-)

diff --git a/examples/tep_termination/main.c b/examples/tep_termination/main.c
index c9ad83f..ffce0b6 100644
--- a/examples/tep_termination/main.c
+++ b/examples/tep_termination/main.c
@@ -110,6 +110,7 @@
 
 #define CMD_LINE_OPT_NB_DEVICES "nb-devices"
 #define CMD_LINE_OPT_UDP_PORT "udp-port"
+#define CMD_LINE_OPT_TX_CHECKSUM "tx-checksum"
 #define CMD_LINE_OPT_FILTER_TYPE "filter-type"
 #define CMD_LINE_OPT_RX_RETRY "rx-retry"
 #define CMD_LINE_OPT_RX_RETRY_DELAY "rx-retry-delay"
@@ -138,6 +139,9 @@ struct vpool {
 /* VXLAN UDP destination port */
 uint16_t udp_port;
 
+/* enable/disable inner TX checksum */
+uint8_t tx_checksum;
+
 /* RX filter type for tunneling packet */
 uint8_t filter_idx;
 
@@ -265,6 +269,7 @@ tep_termination_usage(const char *prgname)
 	RTE_LOG(INFO, VHOST_CONFIG, "%s [EAL options] -- -p PORTMASK\n"
 	"               --udp-port: UDP destination port for VXLAN packet\n"
 	"		--nb-devices[1-64]: The number of virtIO device\n"
+	"               --tx-checksum [0|1]: inner Tx checksum offload\n"
 	"               --filter-type[1-3]: filter type for tunneling packet\n"
 	"                   1: Inner MAC&VLAN and tenent ID\n"
 	"                   2: Inner MAC and tenent ID\n"
@@ -294,6 +299,7 @@ tep_termination_parse_args(int argc, char **argv)
 	static struct option long_option[] = {
 		{CMD_LINE_OPT_NB_DEVICES, required_argument, NULL, 0},
 		{CMD_LINE_OPT_UDP_PORT, required_argument, NULL, 0},
+		{CMD_LINE_OPT_TX_CHECKSUM, required_argument, NULL, 0},
 		{CMD_LINE_OPT_FILTER_TYPE, required_argument, NULL, 0},
 		{CMD_LINE_OPT_RX_RETRY, required_argument, NULL, 0},
 		{CMD_LINE_OPT_RX_RETRY_DELAY, required_argument, NULL, 0},
@@ -378,6 +384,17 @@ tep_termination_parse_args(int argc, char **argv)
 					burst_rx_retry_num = ret;
 			}
 
+			if (!strncmp(long_option[option_index].name, CMD_LINE_OPT_TX_CHECKSUM,
+					sizeof(CMD_LINE_OPT_TX_CHECKSUM))) {
+				ret = parse_num_opt(optarg, 1);
+				if (ret == -1) {
+					RTE_LOG(INFO, VHOST_CONFIG, "Invalid argument for tx-checksum [0|1]\n");
+					tep_termination_usage(prgname);
+					return -1;
+				} else
+					tx_checksum = ret;
+			}
+
 			if (!strncmp(long_option[option_index].name, CMD_LINE_OPT_FILTER_TYPE,
 					sizeof(CMD_LINE_OPT_FILTER_TYPE))) {
 				ret = parse_num_opt(optarg, 3);
diff --git a/examples/tep_termination/vxlan.c b/examples/tep_termination/vxlan.c
index 59b5e2a..786281c 100644
--- a/examples/tep_termination/vxlan.c
+++ b/examples/tep_termination/vxlan.c
@@ -43,6 +43,7 @@
 #include "main.h"
 #include "vxlan.h"
 
+extern uint8_t tx_checksum;
 extern struct vxlan_conf vxdev;
 extern struct ipv4_hdr app_ip_hdr[VXLAN_N_PORTS];
 extern struct ether_hdr app_l2_hdr[VXLAN_N_PORTS];
@@ -54,6 +55,15 @@ extern struct ether_hdr app_l2_hdr[VXLAN_N_PORTS];
 #define _htons(x) (x)
 #endif
 
+static uint16_t
+get_psd_sum(void *l3_hdr, uint16_t ethertype, uint64_t ol_flags)
+{
+	if (ethertype == rte_cpu_to_be_16(ETHER_TYPE_IPv4))
+		return rte_ipv4_phdr_cksum(l3_hdr, ol_flags);
+	else /* assume ethertype == ETHER_TYPE_IPv6 */
+		return rte_ipv6_phdr_cksum(l3_hdr, ol_flags);
+}
+
 /* *
  * Parse an ethernet header to fill the ethertype, outer_l2_len, outer_l3_len and
  * ipproto. This function is able to recognize IPv4/IPv6 with one optional vlan
@@ -95,6 +105,67 @@ parse_ethernet(struct ether_hdr *eth_hdr, union tunnel_offload_info *info,
 
 }
 
+/**
+ * Calculate the checksum of a packet in hardware
+ */
+static uint64_t
+process_inner_cksums(struct ether_hdr *eth_hdr, union tunnel_offload_info *info)
+{
+	void *l3_hdr = NULL;
+	uint16_t ethertype, l4_proto;
+	struct ipv4_hdr *ipv4_hdr;
+	struct ipv6_hdr *ipv6_hdr;
+	struct udp_hdr *udp_hdr;
+	struct tcp_hdr *tcp_hdr;
+	struct sctp_hdr *sctp_hdr;
+	uint64_t ol_flags = 0;
+
+	info->l2_len = sizeof(struct ether_hdr);
+	ethertype = eth_hdr->ether_type;
+
+	if (ethertype == _htons(ETHER_TYPE_VLAN)) {
+		struct vlan_hdr *vlan_hdr = (struct vlan_hdr *)(eth_hdr + 1);
+		info->l2_len  += sizeof(struct vlan_hdr);
+		ethertype = vlan_hdr->eth_proto;
+	}
+
+	l3_hdr = (char *)eth_hdr + info->l2_len;
+
+	if (ethertype == _htons(ETHER_TYPE_IPv4)) {
+		ipv4_hdr = l3_hdr;
+		ipv4_hdr->hdr_checksum = 0;
+		ol_flags |= PKT_TX_IPV4;
+		ol_flags |= PKT_TX_IP_CKSUM;
+		info->l3_len = sizeof(struct ipv4_hdr);
+		l4_proto = ipv4_hdr->next_proto_id;
+	} else if (ethertype == _htons(ETHER_TYPE_IPv6)) {
+		ipv6_hdr = l3_hdr;
+		info->l3_len = sizeof(struct ipv6_hdr);
+		l4_proto = ipv6_hdr->proto;
+		ol_flags |= PKT_TX_IPV6;
+	} else
+		return 0; /* packet type not supported, nothing to do */
+
+	if (l4_proto == IPPROTO_UDP) {
+		udp_hdr = (struct udp_hdr *)((char *)l3_hdr + info->l3_len);
+		ol_flags |= PKT_TX_UDP_CKSUM;
+		udp_hdr->dgram_cksum = get_psd_sum(l3_hdr,
+				ethertype, ol_flags);
+	} else if (l4_proto == IPPROTO_TCP) {
+		tcp_hdr = (struct tcp_hdr *)((char *)l3_hdr + info->l3_len);
+		ol_flags |= PKT_TX_TCP_CKSUM;
+		tcp_hdr->cksum = get_psd_sum(l3_hdr, ethertype,
+				ol_flags);
+
+	} else if (l4_proto == IPPROTO_SCTP) {
+		sctp_hdr = (struct sctp_hdr *)((char *)l3_hdr + info->l3_len);
+		sctp_hdr->cksum = 0;
+		ol_flags |= PKT_TX_SCTP_CKSUM;
+	}
+
+	return ol_flags;
+}
+
 int
 decapsulation(struct rte_mbuf *pkt)
 {
@@ -129,6 +200,7 @@ encapsulation(struct rte_mbuf *m, uint8_t vport_id)
 {
 	uint64_t ol_flags = 0;
 	uint32_t old_len = m->pkt_len, hash;
+	union tunnel_offload_info tx_offload = { .data = 0 };
 	struct ether_hdr *phdr = rte_pktmbuf_mtod(m, struct ether_hdr *);
 
 	/*Allocate space for new ethernet, IPv4, UDP and VXLAN headers*/
@@ -151,6 +223,14 @@ encapsulation(struct rte_mbuf *m, uint8_t vport_id)
 	ol_flags |= PKT_TX_OUTER_IP_CKSUM;
 	ip->hdr_checksum = 0;
 
+	/* inner IP checksum offload */
+	if (tx_checksum) {
+		ol_flags |= process_inner_cksums(phdr, &tx_offload);
+		m->l2_len = tx_offload.l2_len;
+		m->l3_len = tx_offload.l3_len;
+		m->l2_len += ETHER_VXLAN_HLEN;
+	}
+
 	m->outer_l2_len = sizeof(struct ether_hdr);
 	m->outer_l3_len = sizeof(struct ipv4_hdr);
 
-- 
1.7.7.6