[dpdk-dev] [PATCH v4] examples/l3fwd: ipv4 and udp/tcp cksum verification through software

[Usama Nadeem <usama.nadeem@emumba.com>]

checks if ipv4 and udptcp cksum offload capability available
If not available, cksum is verified through software
If cksum is corrupt, packet is dropped, rest of the packets
are forwarded back.

Bugzilla ID:545
Signed-off-by: Usama Nadeem <usama.nadeem@emumba.com>
---
 examples/l3fwd/l3fwd.h     |  6 ++++
 examples/l3fwd/l3fwd_lpm.c | 72 ++++++++++++++++++++++++++++++++++++--
 examples/l3fwd/main.c      | 33 +++++++++++++++--
 3 files changed, 105 insertions(+), 6 deletions(-)

diff --git a/examples/l3fwd/l3fwd.h b/examples/l3fwd/l3fwd.h
index a808d60247..c2c21a91fb 100644
--- a/examples/l3fwd/l3fwd.h
+++ b/examples/l3fwd/l3fwd.h
@@ -55,6 +55,8 @@
 #define L3FWD_HASH_ENTRIES		(1024*1024*1)
 #endif
 #define HASH_ENTRY_NUMBER_DEFAULT	4
+extern bool l3_sft_cksum;
+extern bool l4_sft_cksum;
 
 struct mbuf_table {
 	uint16_t len;
@@ -210,6 +212,10 @@ em_main_loop(__rte_unused void *dummy);
 int
 lpm_main_loop(__rte_unused void *dummy);
 
+int
+check_software_cksum(struct rte_mbuf **pkts_burst,
+struct rte_mbuf **pkts_burst_to_send, int nb_rx);
+
 int
 fib_main_loop(__rte_unused void *dummy);
 
diff --git a/examples/l3fwd/l3fwd_lpm.c b/examples/l3fwd/l3fwd_lpm.c
index 232b606b54..ecaf323943 100644
--- a/examples/l3fwd/l3fwd_lpm.c
+++ b/examples/l3fwd/l3fwd_lpm.c
@@ -26,6 +26,7 @@
 #include <rte_udp.h>
 #include <rte_lpm.h>
 #include <rte_lpm6.h>
+#include <rte_net.h>
 
 #include "l3fwd.h"
 #include "l3fwd_event.h"
@@ -139,16 +140,65 @@ lpm_get_dst_port_with_ipv4(const struct lcore_conf *qconf, struct rte_mbuf *pkt,
 #include "l3fwd_lpm.h"
 #endif
 
+
+int check_software_cksum(struct rte_mbuf **pkts_burst,
+struct rte_mbuf **pkts_burst_to_send, int nb_rx)
+{
+	int j;
+	int i = 0;
+	struct rte_net_hdr_lens hdr_lens;
+	struct rte_ipv4_hdr *ipv4_hdr;
+	void *l3_hdr;
+	void *l4_hdr;
+	rte_be16_t prev_cksum;
+	int dropped_pkts_udp_tcp = 0;
+	int dropped_pkts_ipv4 = 0;
+	bool dropped;
+	for (j = 0; j < nb_rx; j++) {
+		dropped = false;
+		rte_net_get_ptype(pkts_burst[j], &hdr_lens, RTE_PTYPE_ALL_MASK);
+		l3_hdr = rte_pktmbuf_mtod_offset(pkts_burst[j],
+		void *, hdr_lens.l2_len);
+		l4_hdr = rte_pktmbuf_mtod_offset(pkts_burst[j],
+		void *, hdr_lens.l2_len + hdr_lens.l3_len);
+		ipv4_hdr = l3_hdr;
+		prev_cksum = ipv4_hdr->hdr_checksum;
+		ipv4_hdr->hdr_checksum = 0;
+		ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
+
+		if (l3_sft_cksum && prev_cksum != ipv4_hdr->hdr_checksum) {
+			rte_pktmbuf_free(pkts_burst[j]);
+			dropped_pkts_ipv4++;
+			dropped = true;
+		} else if (l4_sft_cksum &&
+				rte_ipv4_udptcp_cksum_verify
+				(l3_hdr, l4_hdr) != 0) {
+
+			rte_pktmbuf_free(pkts_burst[j]);
+			dropped_pkts_udp_tcp++;
+			dropped = true;
+		}
+		if (dropped == false) {
+			pkts_burst_to_send[i] = pkts_burst[j];
+			i++;
+		}
+
+	}
+	return dropped_pkts_udp_tcp+dropped_pkts_ipv4;
+}
+
 /* main processing loop */
 int
 lpm_main_loop(__rte_unused void *dummy)
 {
 	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
+	struct rte_mbuf *pkts_burst_to_send[MAX_PKT_BURST];
 	unsigned lcore_id;
 	uint64_t prev_tsc, diff_tsc, cur_tsc;
 	int i, nb_rx;
 	uint16_t portid;
 	uint8_t queueid;
+	int dropped;
 	struct lcore_conf *qconf;
 	const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1) /
 		US_PER_S * BURST_TX_DRAIN_US;
@@ -209,19 +259,35 @@ lpm_main_loop(__rte_unused void *dummy)
 			if (nb_rx == 0)
 				continue;
 
+			if (l3_sft_cksum || l4_sft_cksum) {
+				dropped = check_software_cksum(pkts_burst,
+				pkts_burst_to_send,	nb_rx);
+
+				nb_rx = nb_rx-dropped;
+			}
+
+
 #if defined RTE_ARCH_X86 || defined __ARM_NEON \
 			 || defined RTE_ARCH_PPC_64
+		if (l3_sft_cksum == false && l4_sft_cksum == false)
 			l3fwd_lpm_send_packets(nb_rx, pkts_burst,
 						portid, qconf);
+		else
+			l3fwd_lpm_send_packets(nb_rx, pkts_burst_to_send,
+						portid, qconf);
+
 #else
-			l3fwd_lpm_no_opt_send_packets(nb_rx, pkts_burst,
+			if (l3_sft_cksum == false && l4_sft_cksum == false)
+				l3fwd_lpm_no_opt_send_packets(nb_rx, pkts_burst,
 							portid, qconf);
+			else
+				l3fwd_lpm_no_opt_send_packets(nb_rx,
+				pkts_burst_to_send, portid, qconf);
+
 #endif /* X86 */
 		}
-
 		cur_tsc = rte_rdtsc();
 	}
-
 	return 0;
 }
 
diff --git a/examples/l3fwd/main.c b/examples/l3fwd/main.c
index 00ac267af1..a54aca070d 100644
--- a/examples/l3fwd/main.c
+++ b/examples/l3fwd/main.c
@@ -61,6 +61,9 @@ static uint16_t nb_txd = RTE_TEST_TX_DESC_DEFAULT;
 /**< Ports set in promiscuous mode off by default. */
 static int promiscuous_on;
 
+bool l3_sft_cksum;
+bool l4_sft_cksum;
+
 /* Select Longest-Prefix, Exact match or Forwarding Information Base. */
 enum L3FWD_LOOKUP_MODE {
 	L3FWD_LOOKUP_DEFAULT,
@@ -123,7 +126,6 @@ static struct rte_eth_conf port_conf = {
 		.mq_mode = ETH_MQ_RX_RSS,
 		.max_rx_pkt_len = RTE_ETHER_MAX_LEN,
 		.split_hdr_size = 0,
-		.offloads = DEV_RX_OFFLOAD_CHECKSUM,
 	},
 	.rx_adv_conf = {
 		.rss_conf = {
@@ -981,6 +983,7 @@ prepare_ptype_parser(uint16_t portid, uint16_t queueid)
 	return 0;
 }
 
+
 static void
 l3fwd_poll_resource_setup(void)
 {
@@ -993,7 +996,8 @@ l3fwd_poll_resource_setup(void)
 	unsigned int nb_ports;
 	unsigned int lcore_id;
 	int ret;
-
+	l3_sft_cksum = false;
+	l4_sft_cksum = false;
 	if (check_lcore_params() < 0)
 		rte_exit(EXIT_FAILURE, "check_lcore_params failed\n");
 
@@ -1034,11 +1038,34 @@ l3fwd_poll_resource_setup(void)
 			rte_exit(EXIT_FAILURE,
 				"Error during getting device (port %u) info: %s\n",
 				portid, strerror(-ret));
-
 		if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
 			local_port_conf.txmode.offloads |=
 				DEV_TX_OFFLOAD_MBUF_FAST_FREE;
 
+		if (dev_info.rx_offload_capa & DEV_RX_OFFLOAD_IPV4_CKSUM)
+			local_port_conf.rxmode.offloads |=
+			DEV_RX_OFFLOAD_IPV4_CKSUM;
+		else {
+			l3_sft_cksum = true;
+			printf("WARNING: IPV4 checksum offload not available.\n");
+			}
+
+		if (dev_info.rx_offload_capa & DEV_RX_OFFLOAD_UDP_CKSUM)
+			local_port_conf.rxmode.offloads |=
+				DEV_RX_OFFLOAD_UDP_CKSUM;
+		else {
+			l4_sft_cksum = true;
+			printf("WARNING: UDP checksum offload not available.\n");
+		}
+
+		if (dev_info.rx_offload_capa & DEV_RX_OFFLOAD_TCP_CKSUM)
+			local_port_conf.rxmode.offloads |=
+				DEV_RX_OFFLOAD_TCP_CKSUM;
+		else {
+			l4_sft_cksum = true;
+			printf("WARNING: TCP checksum offload not available.\n");
+		}
+
 		local_port_conf.rx_adv_conf.rss_conf.rss_hf &=
 			dev_info.flow_type_rss_offloads;
 
-- 
2.25.1