net/tap: do not set remote MAC if not necessary

Check for the current MAC address on both the remote and the tap
netdevices before setting a new value.

While there, remove wrong empty lines and ensure tap_ioctl() return
value is negative, just like what is done throughout this code.

Fixes: 2bc06869cd94 ("net/tap: add remote netdevice traffic capture")

Signed-off-by: Pascal Mazon <pascal.mazon@6wind.com>

diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index 26a7f84..49549b4 100644 (file)
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -705,11 +705,11 @@ tap_allmulti_disable(struct rte_eth_dev *dev)
                tap_flow_implicit_destroy(pmd, TAP_REMOTE_ALLMULTI);
 }
 
-
 static void
 tap_mac_set(struct rte_eth_dev *dev, struct ether_addr *mac_addr)
 {
        struct pmd_internals *pmd = dev->data->dev_private;
+       enum ioctl_mode mode = LOCAL_ONLY;
        struct ifreq ifr;
 
        if (is_zero_ether_addr(mac_addr)) {
@@ -718,15 +718,20 @@ tap_mac_set(struct rte_eth_dev *dev, struct ether_addr *mac_addr)
                return;
        }
        /* Check the actual current MAC address on the tap netdevice */
-       if (tap_ioctl(pmd, SIOCGIFHWADDR, &ifr, 0, LOCAL_ONLY) != 0)
+       if (tap_ioctl(pmd, SIOCGIFHWADDR, &ifr, 0, LOCAL_ONLY) < 0)
                return;
        if (is_same_ether_addr((struct ether_addr *)&ifr.ifr_hwaddr.sa_data,
                               mac_addr))
                return;
-
+       /* Check the current MAC address on the remote */
+       if (tap_ioctl(pmd, SIOCGIFHWADDR, &ifr, 0, REMOTE_ONLY) < 0)
+               return;
+       if (!is_same_ether_addr((struct ether_addr *)&ifr.ifr_hwaddr.sa_data,
+                              mac_addr))
+               mode = LOCAL_AND_REMOTE;
        ifr.ifr_hwaddr.sa_family = AF_LOCAL;
        rte_memcpy(ifr.ifr_hwaddr.sa_data, mac_addr, ETHER_ADDR_LEN);
-       if (tap_ioctl(pmd, SIOCSIFHWADDR, &ifr, 1, LOCAL_AND_REMOTE) < 0)
+       if (tap_ioctl(pmd, SIOCSIFHWADDR, &ifr, 1, mode) < 0)
                return;
        rte_memcpy(&pmd->eth_addr, mac_addr, ETHER_ADDR_LEN);
        if (pmd->remote_if_index) {