[dpdk-dev] [PATCH] example/l2fwd-event: add option to configure forwarding info

[<pbhagavatula@marvell.com>]

From: Pavan Nikhilesh <pbhagavatula@marvell.com>

Current l2fwd-event application statically configures adjacent ports as
destination ports for forwarding the traffic.

Add a config option to pass the forwarding port pair mapping which allows
the user to configure forwarding port mapping.

If no config argument is specified, destination port map is not
changed and traffic gets forwarded with existing mapping.

To align port/queue configuration of each lcore with destination port
map, port/queue configuration of each lcore gets modified when config
option is specificed.

Ex: ./l2fwd-event -c 0xff -- -p 0x3f -q 2 --config="(0,3)(1,4)(2,5)"

With above config option, traffic received from portid = 0 gets forwarded
to port = 3 and vice versa, similarly traffic gets forwarded on other port
pairs (1,4) and (2,5).

Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
---
 doc/guides/sample_app_ug/l2_forward_event.rst |   2 +
 examples/l2fwd-event/l2fwd_common.h           |   1 +
 examples/l2fwd-event/main.c                   | 180 +++++++++++++++---
 3 files changed, 158 insertions(+), 25 deletions(-)

diff --git a/doc/guides/sample_app_ug/l2_forward_event.rst b/doc/guides/sample_app_ug/l2_forward_event.rst
index 8c519c304..8bdf352c4 100644
--- a/doc/guides/sample_app_ug/l2_forward_event.rst
+++ b/doc/guides/sample_app_ug/l2_forward_event.rst
@@ -66,6 +66,8 @@ where,
 
 *   --eventq-sched=SCHED_MODE: Event queue schedule mode, Ordered, Atomic or Parallel. Atomic by default.
 
+*   --config: Configure forwarding port pair mapping. Alternate port pairs by default.
+
 Sample usage commands are given below to run the application into different mode:
 
 Poll mode with 4 lcores, 16 ports and 8 RX queues per lcore and MAC address updating enabled,
diff --git a/examples/l2fwd-event/l2fwd_common.h b/examples/l2fwd-event/l2fwd_common.h
index 7e33ee749..4e8b2fe14 100644
--- a/examples/l2fwd-event/l2fwd_common.h
+++ b/examples/l2fwd-event/l2fwd_common.h
@@ -69,6 +69,7 @@ struct l2fwd_resources {
 	uint8_t sched_type;
 	uint8_t mac_updating;
 	uint8_t rx_queue_per_lcore;
+	uint8_t port_pairs;
 	uint16_t nb_rxd;
 	uint16_t nb_txd;
 	uint32_t enabled_port_mask;
diff --git a/examples/l2fwd-event/main.c b/examples/l2fwd-event/main.c
index 89a6bb9a4..92890d1ae 100644
--- a/examples/l2fwd-event/main.c
+++ b/examples/l2fwd-event/main.c
@@ -2,6 +2,8 @@
  * Copyright(C) 2019 Marvell International Ltd.
  */
 
+#include <rte_string_fns.h>
+
 #include "l2fwd_event.h"
 #include "l2fwd_poll.h"
 
@@ -22,7 +24,9 @@ l2fwd_event_usage(const char *prgname)
 	       "          Default mode = eventdev\n"
 	       "  --eventq-sched: Event queue schedule type, ordered, atomic or parallel.\n"
 	       "                  Default: atomic\n"
-	       "                  Valid only if --mode=eventdev\n\n",
+	       "                  Valid only if --mode=eventdev\n"
+	       "  --config: Configure forwarding port pair mapping\n"
+	       "	    Default: alternate port pairs\n\n",
 	       prgname);
 }
 
@@ -99,6 +103,69 @@ l2fwd_event_parse_eventq_sched(const char *optarg,
 		rsrc->sched_type = RTE_SCHED_TYPE_PARALLEL;
 }
 
+static int
+l2fwd_parse_port_pair_config(const char *q_arg, struct l2fwd_resources *rsrc)
+{
+	enum fieldnames {
+		FLD_PORT1 = 0,
+		FLD_PORT2,
+		_NUM_FLD
+	};
+	const char *p, *p0 = q_arg;
+	uint16_t int_fld[_NUM_FLD];
+	char *str_fld[_NUM_FLD];
+	uint16_t port_pair = 0;
+	unsigned int size;
+	char s[256];
+	char *end;
+	int i;
+
+	while ((p = strchr(p0, '(')) != NULL) {
+		++p;
+		p0 = strchr(p, ')');
+		if (p0 == NULL)
+			return -1;
+
+		size = p0 - p;
+		if (size >= sizeof(s))
+			return -1;
+
+		snprintf(s, sizeof(s), "%.*s", size, p);
+		if (rte_strsplit(s, sizeof(s), str_fld,
+					_NUM_FLD, ',') != _NUM_FLD)
+			return -1;
+
+		for (i = 0; i < _NUM_FLD; i++) {
+			errno = 0;
+			int_fld[i] = strtoul(str_fld[i], &end, 0);
+			if (errno != 0 || end == str_fld[i] || int_fld[i] > 255)
+				return -1;
+		}
+
+		if (port_pair >= RTE_MAX_ETHPORTS / 2) {
+			printf("exceeded max number of port pair params: Current %d Max = %d\n",
+			       port_pair, RTE_MAX_ETHPORTS / 2);
+			return -1;
+		}
+
+		if ((rsrc->dst_ports[int_fld[FLD_PORT1]] != UINT32_MAX) ||
+			(rsrc->dst_ports[int_fld[FLD_PORT2]] != UINT32_MAX)) {
+			printf("Duplicate port pair (%d,%d) config\n",
+					int_fld[FLD_PORT1], int_fld[FLD_PORT2]);
+			return -1;
+		}
+
+		rsrc->dst_ports[int_fld[FLD_PORT1]] = int_fld[FLD_PORT2];
+		rsrc->dst_ports[int_fld[FLD_PORT2]] = int_fld[FLD_PORT1];
+
+		port_pair++;
+	}
+
+	rsrc->port_pairs = true;
+
+	return 0;
+}
+
 static const char short_options[] =
 	"p:"  /* portmask */
 	"q:"  /* number of queues */
@@ -109,6 +176,7 @@ static const char short_options[] =
 #define CMD_LINE_OPT_NO_MAC_UPDATING "no-mac-updating"
 #define CMD_LINE_OPT_MODE "mode"
 #define CMD_LINE_OPT_EVENTQ_SCHED "eventq-sched"
+#define CMD_LINE_OPT_PORT_PAIR_CONF "config"
 
 enum {
 	/* long options mapped to a short option */
@@ -119,12 +187,12 @@ enum {
 	CMD_LINE_OPT_MIN_NUM = 256,
 	CMD_LINE_OPT_MODE_NUM,
 	CMD_LINE_OPT_EVENTQ_SCHED_NUM,
+	CMD_LINE_OPT_PORT_PAIR_CONF_NUM,
 };
 
 /* Parse the argument given in the command line of the application */
 static int
-l2fwd_event_parse_args(int argc, char **argv,
-		struct l2fwd_resources *rsrc)
+l2fwd_event_parse_args(int argc, char **argv, struct l2fwd_resources *rsrc)
 {
 	int mac_updating = 1;
 	struct option lgopts[] = {
@@ -134,12 +202,18 @@ l2fwd_event_parse_args(int argc, char **argv,
 							CMD_LINE_OPT_MODE_NUM},
 		{ CMD_LINE_OPT_EVENTQ_SCHED, required_argument, NULL,
 						CMD_LINE_OPT_EVENTQ_SCHED_NUM},
+		{ CMD_LINE_OPT_PORT_PAIR_CONF, required_argument, NULL,
+					CMD_LINE_OPT_PORT_PAIR_CONF_NUM},
 		{NULL, 0, 0, 0}
 	};
 	int opt, ret, timer_secs;
 	char *prgname = argv[0];
-	char **argvopt;
+	uint16_t port_id;
 	int option_index;
+	char **argvopt;
+	/* reset l2fwd_dst_ports */
+	for (port_id = 0; port_id < RTE_MAX_ETHPORTS; port_id++)
+		rsrc->dst_ports[port_id] = UINT32_MAX;
 
 	argvopt = argv;
 	while ((opt = getopt_long(argc, argvopt, short_options,
@@ -189,6 +263,15 @@ l2fwd_event_parse_args(int argc, char **argv,
 			l2fwd_event_parse_eventq_sched(optarg, rsrc);
 			break;
 
+		case CMD_LINE_OPT_PORT_PAIR_CONF_NUM:
+			ret = l2fwd_parse_port_pair_config(optarg, rsrc);
+			if (ret) {
+				printf("Invalid port pair config\n");
+				l2fwd_event_usage(prgname);
+				return -1;
+			}
+			break;
+
 		/* long options */
 		case 0:
 			break;
@@ -209,6 +292,51 @@ l2fwd_event_parse_args(int argc, char **argv,
 	return ret;
 }
 
+/*
+ * Check port pair config with enabled port mask,
+ * and for valid port pair combinations.
+ */
+static int
+check_port_pair_config(struct l2fwd_resources *rsrc)
+{
+	uint32_t port_pair_mask = 0;
+	uint32_t portid;
+	uint16_t index;
+
+	for (index = 0; index < rte_eth_dev_count_avail(); index++) {
+		if ((rsrc->enabled_port_mask & (1 << index)) == 0)
+			continue;
+
+		portid = rsrc->dst_ports[index];
+		if (portid == UINT32_MAX) {
+			printf("port %u is enabled in but no valid port pair\n",
+			       index);
+			return -1;
+		}
+
+		if (!rte_eth_dev_is_valid_port(index)) {
+			printf("port %u is not valid\n", index);
+			return -1;
+		}
+
+		if (!rte_eth_dev_is_valid_port(portid)) {
+			printf("port %u is not valid\n", portid);
+			return -1;
+		}
+
+		if (port_pair_mask & (1 << portid) &&
+				rsrc->dst_ports[portid] != index) {
+			printf("port %u is used in other port pairs\n", portid);
+			return -1;
+		}
+
+		port_pair_mask |= (1 << portid);
+		port_pair_mask |= (1 << index);
+	}
+
+	return 0;
+}
+
 static int
 l2fwd_launch_one_lcore(void *args)
 {
@@ -465,31 +593,33 @@ main(int argc, char **argv)
 		rte_panic("Invalid portmask; possible (0x%x)\n",
 			(1 << nb_ports) - 1);
 
-	/* reset l2fwd_dst_ports */
-	for (port_id = 0; port_id < RTE_MAX_ETHPORTS; port_id++)
-		rsrc->dst_ports[port_id] = 0;
-	last_port = 0;
+	if (!rsrc->port_pairs) {
+		last_port = 0;
+		/*
+		 * Each logical core is assigned a dedicated TX queue on each
+		 * port.
+		 */
+		RTE_ETH_FOREACH_DEV(port_id) {
+			/* skip ports that are not enabled */
+			if ((rsrc->enabled_port_mask & (1 << port_id)) == 0)
+				continue;
 
-	/*
-	 * Each logical core is assigned a dedicated TX queue on each port.
-	 */
-	RTE_ETH_FOREACH_DEV(port_id) {
-		/* skip ports that are not enabled */
-		if ((rsrc->enabled_port_mask & (1 << port_id)) == 0)
-			continue;
+			if (nb_ports_in_mask % 2) {
+				rsrc->dst_ports[port_id] = last_port;
+				rsrc->dst_ports[last_port] = port_id;
+			} else {
+				last_port = port_id;
+			}
 
+			nb_ports_in_mask++;
+		}
 		if (nb_ports_in_mask % 2) {
-			rsrc->dst_ports[port_id] = last_port;
-			rsrc->dst_ports[last_port] = port_id;
-		} else {
-			last_port = port_id;
+			printf("Notice: odd number of ports in portmask.\n");
+			rsrc->dst_ports[last_port] = last_port;
 		}
-
-		nb_ports_in_mask++;
-	}
-	if (nb_ports_in_mask % 2) {
-		printf("Notice: odd number of ports in portmask.\n");
-		rsrc->dst_ports[last_port] = last_port;
+	} else {
+		if (check_port_pair_config(rsrc) < 0)
+			rte_panic("Invalid port pair config\n");
 	}
 
 	nb_mbufs = RTE_MAX(nb_ports * (RTE_TEST_RX_DESC_DEFAULT +
-- 
2.25.1