[dpdk-dev] [PATCH 1/2] examples/l2fwd: Add new option to enable/disable MAC addresses tweaking

[Maxime Coquelin]

l2fwd could be useful for testing virtual devices without the need
of physical ones.

To achieve this, this patch adds a new option to enable/disable the
MAC addresses tweaking done at forwarding time: --[no-]mac-tweaking

By default, MAC address tweaking remains enabled, to keep consistency
with previous usage.

Signed-off-by: Maxime Coquelin <maxime.coquelin at redhat.com>
---
 examples/l2fwd/main.c | 39 +++++++++++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/examples/l2fwd/main.c b/examples/l2fwd/main.c
index 8897921..2693be1 100644
--- a/examples/l2fwd/main.c
+++ b/examples/l2fwd/main.c
@@ -74,6 +74,9 @@

 static volatile bool force_quit;

+/* MAC tweaking enabled by default */
+static int mac_tweaking = 1;
+
 #define RTE_LOGTYPE_L2FWD RTE_LOGTYPE_USER1

 #define NB_MBUF   8192
@@ -186,23 +189,32 @@ print_stats(void)
 }

 static void
-l2fwd_simple_forward(struct rte_mbuf *m, unsigned portid)
+l2fwd_mac_tweaking(struct rte_mbuf *m, unsigned dest_portid)
 {
        struct ether_hdr *eth;
        void *tmp;
-       unsigned dst_port;
-       int sent;
-       struct rte_eth_dev_tx_buffer *buffer;

-       dst_port = l2fwd_dst_ports[portid];
        eth = rte_pktmbuf_mtod(m, struct ether_hdr *);

        /* 02:00:00:00:00:xx */
        tmp = &eth->d_addr.addr_bytes[0];
-       *((uint64_t *)tmp) = 0x000000000002 + ((uint64_t)dst_port << 40);
+       *((uint64_t *)tmp) = 0x000000000002 + ((uint64_t)dest_portid << 40);

        /* src addr */
-       ether_addr_copy(&l2fwd_ports_eth_addr[dst_port], &eth->s_addr);
+       ether_addr_copy(&l2fwd_ports_eth_addr[dest_portid], &eth->s_addr);
+}
+
+static void
+l2fwd_simple_forward(struct rte_mbuf *m, unsigned portid)
+{
+       unsigned dst_port;
+       int sent;
+       struct rte_eth_dev_tx_buffer *buffer;
+
+       dst_port = l2fwd_dst_ports[portid];
+
+       if (mac_tweaking)
+               l2fwd_mac_tweaking(m, dst_port);

        buffer = tx_buffer[dst_port];
        sent = rte_eth_tx_buffer(dst_port, 0, buffer, m);
@@ -322,7 +334,11 @@ l2fwd_usage(const char *prgname)
        printf("%s [EAL options] -- -p PORTMASK [-q NQ]\n"
               "  -p PORTMASK: hexadecimal bitmask of ports to configure\n"
               "  -q NQ: number of queue (=ports) per lcore (default is 1)\n"
-                  "  -T PERIOD: statistics will be refreshed each PERIOD 
seconds (0 to disable, 10 default, 86400 maximum)\n",
+                  "  -T PERIOD: statistics will be refreshed each PERIOD 
seconds (0 to disable, 10 default, 86400 maximum)\n"
+                  "  --[no-]mac-tweaking: Enable or disable MAC addresses 
tweaking (enabled by default)\n"
+                  "      When enabled:\n"
+                  "       - The source MAC address is replaced by the TX port 
MAC address\n"
+                  "       - The destination MAC address is replaced by 
02:00:00:00:00:TX_PORT_ID\n",
               prgname);
 }

@@ -386,6 +402,8 @@ l2fwd_parse_args(int argc, char **argv)
        int option_index;
        char *prgname = argv[0];
        static struct option lgopts[] = {
+               { "mac-tweaking", no_argument, &mac_tweaking, 1},
+               { "no-mac-tweaking", no_argument, &mac_tweaking, 0},
                {NULL, 0, 0, 0}
        };

@@ -428,8 +446,7 @@ l2fwd_parse_args(int argc, char **argv)

                /* long options */
                case 0:
-                       l2fwd_usage(prgname);
-                       return -1;
+                       break;

                default:
                        l2fwd_usage(prgname);
@@ -542,6 +559,8 @@ main(int argc, char **argv)
        if (ret < 0)
                rte_exit(EXIT_FAILURE, "Invalid L2FWD arguments\n");

+       printf("MAC tweaking %s\n", mac_tweaking ? "enabled" : "disabled");
+
        /* convert to number of cycles */
        timer_period *= rte_get_timer_hz();

-- 
2.7.4