[dpdk-dev] [PATCH] [v2 1/1] examples/l2fwd: add cmdline option for forwarding port info

[vattunuru at marvell.com]

From: Vamsi Attunuru <vattunuru at marvell.com>

Current l2fwd application configures adjacent ports as destination
ports for forwarding the traffic which is a kind of static mapping
that can not be altered by the command line options.

Patch adds a config option to pass the forwarding port pair mapping
as a command line parameter which allows the user to pass required
forwarding port mapping.

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

When port pair mapping is passed in config option, destination port map
is configured and traffic gets forwarded accordingly.

Ex: ./l2fwd -c 0xff -- -p 0x3f --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: Vamsi Attunuru <vattunuru at marvell.com>
---
V2 Changes:

* Fix command option format in docs.
* Use memcpy instead of snprintf.
* Rephrase if-else condition.

 doc/guides/rel_notes/release_20_05.rst             |   6 +
 .../sample_app_ug/l2_forward_real_virtual.rst      |  18 ++-
 examples/l2fwd/main.c                              | 169 ++++++++++++++++++---
 3 files changed, 172 insertions(+), 21 deletions(-)

diff --git a/doc/guides/rel_notes/release_20_05.rst b/doc/guides/rel_notes/release_20_05.rst
index 000bbf5..69e1798 100644
--- a/doc/guides/rel_notes/release_20_05.rst
+++ b/doc/guides/rel_notes/release_20_05.rst
@@ -62,6 +62,12 @@ New Features
 
   * Added support for matching on IPv4 Time To Live and IPv6 Hop Limit.
 
+* **Added --config command line parameter to l2fwd example.**
+
+  Added new command line option ``--config="(port, port)[,(port, port)]"`` to
+  pass forwarding port details.
+  See the :doc:`doc/guides/sample_app_ug/l2_forward_real_virtual` for more
+  details of this parameter usage.
 
 Removed Items
 -------------
diff --git a/doc/guides/sample_app_ug/l2_forward_real_virtual.rst b/doc/guides/sample_app_ug/l2_forward_real_virtual.rst
index 39d6b00..5c0ee05 100644
--- a/doc/guides/sample_app_ug/l2_forward_real_virtual.rst
+++ b/doc/guides/sample_app_ug/l2_forward_real_virtual.rst
@@ -91,7 +91,10 @@ The application requires a number of command line options:
 
 .. code-block:: console
 
-    ./build/l2fwd [EAL options] -- -p PORTMASK [-q NQ] --[no-]mac-updating
+    ./build/l2fwd [EAL options] -- -p PORTMASK
+                                   [-q NQ]
+                                   --[no-]mac-updating
+                                   --config="(port, port)[,(port, port)]"
 
 where,
 
@@ -99,7 +102,10 @@ where,
 
 *   q NQ: A number of queues (=ports) per lcore (default is 1)
 
-*   --[no-]mac-updating: Enable or disable MAC addresses updating (enabled by default).
+*   --[no-]mac-updating: Enable or disable MAC addresses updating (enabled by default)
+
+*   --config="(port,port)[,(port,port)]": Determines which ports are mapped to
+    which ports for packet forwarding.
 
 To run the application in linux environment with 4 lcores, 16 ports and 8 RX queues per lcore and MAC address
 updating enabled, issue the command:
@@ -108,6 +114,14 @@ updating enabled, issue the command:
 
     $ ./build/l2fwd -l 0-3 -n 4 -- -q 8 -p ffff
 
+To run the application in linux environment with 4 lcores, 4 ports, 8 RX queues
+per lcore and MAC address updating enabled, to forward RX traffic of ports 0 & 1
+on ports 2 & 3 respectively and vice versa, issue the command:
+
+.. code-block:: console
+
+    $ ./build/l2fwd -l 0-3 -n 4 -- -q 8 -p f --config="(0,2)(1,3)"
+
 Refer to the *DPDK Getting Started Guide* for general information on running applications
 and the Environment Abstraction Layer (EAL) options.
 
diff --git a/examples/l2fwd/main.c b/examples/l2fwd/main.c
index 09257aa..98ce164 100644
--- a/examples/l2fwd/main.c
+++ b/examples/l2fwd/main.c
@@ -38,6 +38,7 @@
 #include <rte_ethdev.h>
 #include <rte_mempool.h>
 #include <rte_mbuf.h>
+#include <rte_string_fns.h>
 
 static volatile bool force_quit;
 
@@ -67,6 +68,15 @@ static uint32_t l2fwd_enabled_port_mask = 0;
 /* list of enabled ports */
 static uint32_t l2fwd_dst_ports[RTE_MAX_ETHPORTS];
 
+struct port_pair_params {
+#define NUM_PORTS	2
+	uint16_t port[NUM_PORTS];
+} __rte_cache_aligned;
+
+static struct port_pair_params port_pair_params_array[RTE_MAX_ETHPORTS];
+static struct port_pair_params *port_pair_params;
+static uint16_t nb_port_pair_params;
+
 static unsigned int l2fwd_rx_queue_per_lcore = 1;
 
 #define MAX_RX_QUEUE_PER_LCORE 16
@@ -319,6 +329,60 @@ l2fwd_parse_portmask(const char *portmask)
 	return pm;
 }
 
+static int
+l2fwd_parse_port_pair_config(const char *q_arg)
+{
+	enum fieldnames {
+		FLD_PORT1 = 0,
+		FLD_PORT2,
+		_NUM_FLD
+	};
+	unsigned long int_fld[_NUM_FLD];
+	const char *p, *p0 = q_arg;
+	char *str_fld[_NUM_FLD];
+	unsigned int size;
+	char s[256];
+	char *end;
+	int i;
+
+	nb_port_pair_params = 0;
+
+	while ((p = strchr(p0, '(')) != NULL) {
+		++p;
+		p0 = strchr(p, ')');
+		if (p0 == NULL)
+			return -1;
+
+		size = p0 - p;
+		if (size >= sizeof(s))
+			return -1;
+
+		memcpy(s, p, size);
+		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] >= RTE_MAX_ETHPORTS)
+				return -1;
+		}
+		if (nb_port_pair_params >= RTE_MAX_ETHPORTS/2) {
+			printf("exceeded max number of port pair params: %hu\n",
+				nb_port_pair_params);
+			return -1;
+		}
+		port_pair_params_array[nb_port_pair_params].port[0] =
+				(uint16_t)int_fld[FLD_PORT1];
+		port_pair_params_array[nb_port_pair_params].port[1] =
+				(uint16_t)int_fld[FLD_PORT2];
+		++nb_port_pair_params;
+	}
+	port_pair_params = port_pair_params_array;
+	return 0;
+}
+
 static unsigned int
 l2fwd_parse_nqueue(const char *q_arg)
 {
@@ -361,6 +425,7 @@ static const char short_options[] =
 
 #define CMD_LINE_OPT_MAC_UPDATING "mac-updating"
 #define CMD_LINE_OPT_NO_MAC_UPDATING "no-mac-updating"
+#define CMD_LINE_OPT_CONFIG "config"
 
 enum {
 	/* long options mapped to a short option */
@@ -368,11 +433,13 @@ enum {
 	/* first long only option value must be >= 256, so that we won't
 	 * conflict with short options */
 	CMD_LINE_OPT_MIN_NUM = 256,
+	CMD_LINE_OPT_CONFIG_NUM,
 };
 
 static const struct option lgopts[] = {
 	{ CMD_LINE_OPT_MAC_UPDATING, no_argument, &mac_updating, 1},
 	{ CMD_LINE_OPT_NO_MAC_UPDATING, no_argument, &mac_updating, 0},
+	{ CMD_LINE_OPT_CONFIG, 1, 0, CMD_LINE_OPT_CONFIG_NUM},
 	{NULL, 0, 0, 0}
 };
 
@@ -386,6 +453,7 @@ l2fwd_parse_args(int argc, char **argv)
 	char *prgname = argv[0];
 
 	argvopt = argv;
+	port_pair_params = NULL;
 
 	while ((opt = getopt_long(argc, argvopt, short_options,
 				  lgopts, &option_index)) != EOF) {
@@ -423,7 +491,13 @@ l2fwd_parse_args(int argc, char **argv)
 			break;
 
 		/* long options */
-		case 0:
+		case CMD_LINE_OPT_CONFIG_NUM:
+			ret = l2fwd_parse_port_pair_config(optarg);
+			if (ret) {
+				fprintf(stderr, "Invalid config\n");
+				l2fwd_usage(prgname);
+				return -1;
+			}
 			break;
 
 		default:
@@ -440,6 +514,48 @@ l2fwd_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(void)
+{
+	uint32_t port_pair_config_mask = 0;
+	uint32_t port_pair_mask = 0;
+	uint16_t index, i, portid;
+
+	for (index = 0; index < nb_port_pair_params; index++) {
+		port_pair_mask = 0;
+
+		for (i = 0; i < NUM_PORTS; i++)  {
+			portid = port_pair_params[index].port[i];
+			if ((l2fwd_enabled_port_mask & (1 << portid)) == 0) {
+				printf("port %u is not enabled in port mask\n",
+				       portid);
+				return -1;
+			}
+			if (!rte_eth_dev_is_valid_port(portid)) {
+				printf("port %u is not present on the board\n",
+				       portid);
+				return -1;
+			}
+
+			port_pair_mask |= 1 << portid;
+		}
+
+		if (port_pair_config_mask & port_pair_mask) {
+			printf("port %u is used in other port pairs\n", portid);
+			return -1;
+		}
+		port_pair_config_mask |= port_pair_mask;
+	}
+
+	l2fwd_enabled_port_mask &= port_pair_config_mask;
+
+	return 0;
+}
+
 /* Check the link status of all ports in up to 9s, and print them finally */
 static void
 check_all_ports_link_status(uint32_t port_mask)
@@ -555,6 +671,11 @@ main(int argc, char **argv)
 	if (nb_ports == 0)
 		rte_exit(EXIT_FAILURE, "No Ethernet ports - bye\n");
 
+	if (port_pair_params != NULL) {
+		if (check_port_pair_config() < 0)
+			rte_exit(EXIT_FAILURE, "Invalid port pair config\n");
+	}
+
 	/* check port mask to possible port mask */
 	if (l2fwd_enabled_port_mask & ~((1 << nb_ports) - 1))
 		rte_exit(EXIT_FAILURE, "Invalid portmask; possible (0x%x)\n",
@@ -565,26 +686,35 @@ main(int argc, char **argv)
 		l2fwd_dst_ports[portid] = 0;
 	last_port = 0;
 
-	/*
-	 * Each logical core is assigned a dedicated TX queue on each port.
-	 */
-	RTE_ETH_FOREACH_DEV(portid) {
-		/* skip ports that are not enabled */
-		if ((l2fwd_enabled_port_mask & (1 << portid)) == 0)
-			continue;
+	/* populate destination port details */
+	if (port_pair_params != NULL) {
+		uint16_t idx, p;
 
-		if (nb_ports_in_mask % 2) {
-			l2fwd_dst_ports[portid] = last_port;
-			l2fwd_dst_ports[last_port] = portid;
+		for (idx = 0; idx < (nb_port_pair_params << 1); idx++) {
+			p = idx & 1;
+			portid = port_pair_params[idx >> 1].port[p];
+			l2fwd_dst_ports[portid] =
+				port_pair_params[idx >> 1].port[p ^ 1];
 		}
-		else
-			last_port = portid;
+	} else {
+		RTE_ETH_FOREACH_DEV(portid) {
+			/* skip ports that are not enabled */
+			if ((l2fwd_enabled_port_mask & (1 << portid)) == 0)
+				continue;
 
-		nb_ports_in_mask++;
-	}
-	if (nb_ports_in_mask % 2) {
-		printf("Notice: odd number of ports in portmask.\n");
-		l2fwd_dst_ports[last_port] = last_port;
+			if (nb_ports_in_mask % 2) {
+				l2fwd_dst_ports[portid] = last_port;
+				l2fwd_dst_ports[last_port] = portid;
+			} else {
+				last_port = portid;
+			}
+
+			nb_ports_in_mask++;
+		}
+		if (nb_ports_in_mask % 2) {
+			printf("Notice: odd number of ports in portmask.\n");
+			l2fwd_dst_ports[last_port] = last_port;
+		}
 	}
 
 	rx_lcore_id = 0;
@@ -613,7 +743,8 @@ main(int argc, char **argv)
 
 		qconf->rx_port_list[qconf->n_rx_port] = portid;
 		qconf->n_rx_port++;
-		printf("Lcore %u: RX port %u\n", rx_lcore_id, portid);
+		printf("Lcore %u: RX port %u TX port %u\n", rx_lcore_id,
+		       portid, l2fwd_dst_ports[portid]);
 	}
 
 	nb_mbufs = RTE_MAX(nb_ports * (nb_rxd + nb_txd + MAX_PKT_BURST +
-- 
2.8.4