example: l2fwd_simple: add single-threaded l2fwd example

The ODP distribution is lacking a simple example how to receive and send
packets. The l2fwd is overly complicated because it supports an arbitrary
number of interfaces, bi-directional operation and an arbitrary number of
threads.

To remedy this situation, add l2fwd_simple which is a single-threaded
unidirectional variant of l2fwd for exactly two interfaces. l2fwd_simple
can be used as an example application when learning how to use ODP. The
focus when developing l2fwd_simple was to reduce the code line count to as
small value as possible, and it turned out it requires 165 lines of code.

For unidirectional traffic in single-threaded use cases, l2fwd_simple
performs actually better than l2fwd with single thread, because
l2fwd_simple does not need to poll two interfaces in a single thread.

Signed-off-by: Juha-Matti Tilli <juha-matti.tilli@nokia.com>
Reviewed-by: Petri Savolainen <petri.savolainen@nokia.com>
Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>

5 files changed, 179 insertions, 2 deletions

diff --git a/example/Makefile.am b/example/Makefile.am
index 39d9b0198..5c97fbb64 100644
--- a/example/Makefile.am
+++ b/example/Makefile.am
@@ -1 +1 @@
-SUBDIRS = classifier generator ipsec packet time timer
+SUBDIRS = classifier generator ipsec packet time timer l2fwd_simple
diff --git a/example/l2fwd_simple/.gitignore b/example/l2fwd_simple/.gitignore
new file mode 100644
index 000000000..132673244
--- /dev/null
+++ b/example/l2fwd_simple/.gitignore
@@ -0,0 +1 @@
+odp_l2fwd_simple
diff --git a/example/l2fwd_simple/Makefile.am b/example/l2fwd_simple/Makefile.am
new file mode 100644
index 000000000..88d2915d5
--- /dev/null
+++ b/example/l2fwd_simple/Makefile.am
@@ -0,0 +1,10 @@
+include $(top_srcdir)/example/Makefile.inc
+
+bin_PROGRAMS = odp_l2fwd_simple$(EXEEXT)
+odp_l2fwd_simple_LDFLAGS = $(AM_LDFLAGS) -static
+odp_l2fwd_simple_CFLAGS = $(AM_CFLAGS) -I${top_srcdir}/example
+
+noinst_HEADERS = \
+		  $(top_srcdir)/example/example_debug.h
+
+dist_odp_l2fwd_simple_SOURCES = odp_l2fwd_simple.c
diff --git a/example/l2fwd_simple/odp_l2fwd_simple.c b/example/l2fwd_simple/odp_l2fwd_simple.c
new file mode 100644
index 000000000..11d342f3c
--- /dev/null
+++ b/example/l2fwd_simple/odp_l2fwd_simple.c
@@ -0,0 +1,165 @@
+/* Copyright (c) 2016, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier:     BSD-3-Clause
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+
+#include <odp_api.h>
+#include <odp/helper/linux.h>
+#include <odp/helper/eth.h>
+#include <odp/helper/ip.h>
+
+#define POOL_NUM_PKT 8192
+#define POOL_SEG_LEN 1856
+#define MAX_PKT_BURST 32
+
+struct {
+	odp_pktio_t if0, if1;
+	odp_pktin_queue_t if0in, if1in;
+	odp_pktout_queue_t if0out, if1out;
+	odph_ethaddr_t src, dst;
+} global;
+
+static odp_pktio_t create_pktio(const char *name, odp_pool_t pool,
+				odp_pktin_queue_t *pktin,
+				odp_pktout_queue_t *pktout)
+{
+	odp_pktio_param_t pktio_param;
+	odp_pktin_queue_param_t in_queue_param;
+	odp_pktout_queue_param_t out_queue_param;
+	odp_pktio_t pktio;
+
+	odp_pktio_param_init(&pktio_param);
+
+	pktio = odp_pktio_open(name, pool, &pktio_param);
+	if (pktio == ODP_PKTIO_INVALID) {
+		printf("Failed to open %s\n", name);
+		exit(1);
+	}
+
+	odp_pktin_queue_param_init(&in_queue_param);
+	odp_pktout_queue_param_init(&out_queue_param);
+
+	in_queue_param.op_mode = ODP_PKTIO_OP_MT_UNSAFE;
+
+	if (odp_pktin_queue_config(pktio, &in_queue_param)) {
+		printf("Failed to config input queue for %s\n", name);
+		exit(1);
+	}
+
+	out_queue_param.op_mode = ODP_PKTIO_OP_MT_UNSAFE;
+
+	if (odp_pktout_queue_config(pktio, &out_queue_param)) {
+		printf("Failed to config output queue for %s\n", name);
+		exit(1);
+	}
+
+	if (odp_pktin_queue(pktio, pktin, 1) != 1) {
+		printf("pktin queue query failed for %s\n", name);
+		exit(1);
+	}
+	if (odp_pktout_queue(pktio, pktout, 1) != 1) {
+		printf("pktout queue query failed for %s\n", name);
+		exit(1);
+	}
+	return pktio;
+}
+
+static void *run_worker(void *arg ODP_UNUSED)
+{
+	odp_packet_t pkt_tbl[MAX_PKT_BURST];
+	int pkts, sent, tx_drops, i;
+
+	if (odp_pktio_start(global.if0)) {
+		printf("unable to start input interface\n");
+		exit(1);
+	}
+	printf("started input interface\n");
+	if (odp_pktio_start(global.if1)) {
+		printf("unable to start output interface\n");
+		exit(1);
+	}
+	printf("started output interface\n");
+	printf("started all\n");
+
+	for (;;) {
+		pkts = odp_pktin_recv(global.if0in, pkt_tbl, MAX_PKT_BURST);
+		if (odp_unlikely(pkts <= 0))
+			continue;
+		for (i = 0; i < pkts; i++) {
+			odp_packet_t pkt = pkt_tbl[i];
+			odph_ethhdr_t *eth;
+
+			if (odp_unlikely(!odp_packet_has_eth(pkt))) {
+				printf("warning: packet has no eth header\n");
+				return NULL;
+			}
+			eth = (odph_ethhdr_t *)odp_packet_l2_ptr(pkt, NULL);
+			eth->src = global.src;
+			eth->dst = global.dst;
+		}
+		sent = odp_pktout_send(global.if1out, pkt_tbl, pkts);
+		if (sent < 0)
+			sent = 0;
+		tx_drops = pkts - sent;
+		if (odp_unlikely(tx_drops))
+			odp_packet_free_multi(&pkt_tbl[sent], tx_drops);
+	}
+	return NULL;
+}
+
+int main(int argc, char **argv)
+{
+	odp_pool_t pool;
+	odp_pool_param_t params;
+	odp_cpumask_t cpumask;
+	odph_linux_pthread_t thd;
+
+	if (argc != 5 ||
+	    odph_eth_addr_parse(&global.dst, argv[3]) != 0 ||
+	    odph_eth_addr_parse(&global.src, argv[4]) != 0) {
+		printf("Usage: odp_l2fwd_simple eth0 eth1 01:02:03:04:05:06"
+		       " 07:08:09:0a:0b:0c\n");
+		printf("Where eth0 and eth1 are the used interfaces"
+		       " (must have 2 of them)\n");
+		printf("And the hexadecimal numbers are destination MAC address"
+		       " and source MAC address\n");
+		exit(1);
+	}
+
+	if (odp_init_global(NULL, NULL)) {
+		printf("Error: ODP global init failed.\n");
+		exit(1);
+	}
+
+	if (odp_init_local(ODP_THREAD_CONTROL)) {
+		printf("Error: ODP local init failed.\n");
+		exit(1);
+	}
+
+	/* Create packet pool */
+	odp_pool_param_init(&params);
+	params.pkt.seg_len = POOL_SEG_LEN;
+	params.pkt.len     = POOL_SEG_LEN;
+	params.pkt.num     = POOL_NUM_PKT;
+	params.type        = ODP_POOL_PACKET;
+
+	pool = odp_pool_create("packet pool", &params);
+
+	if (pool == ODP_POOL_INVALID) {
+		printf("Error: packet pool create failed.\n");
+		exit(1);
+	}
+
+	global.if0 = create_pktio(argv[1], pool, &global.if0in, &global.if0out);
+	global.if1 = create_pktio(argv[2], pool, &global.if1in, &global.if1out);
+
+	odp_cpumask_default_worker(&cpumask, 1);
+	odph_linux_pthread_create(&thd, &cpumask, run_worker, NULL,
+				  ODP_THREAD_WORKER);
+	odph_linux_pthread_join(&thd, 1);
+	return 0;
+}
diff --git a/example/m4/configure.m4 b/example/m4/configure.m4
index bc90f820c..1710a31b8 100644
--- a/example/m4/configure.m4
+++ b/example/m4/configure.m4
@@ -4,4 +4,5 @@ AC_CONFIG_FILES([example/classifier/Makefile
 		 example/Makefile
 		 example/packet/Makefile
 		 example/time/Makefile
-		 example/timer/Makefile])
+		 example/timer/Makefile
+		 example/l2fwd_simple/Makefile])