linux-cp: fix tap interface attrs in case the sw pool realloc'd

[vpp.git] / src / plugins / linux-cp / lcp_interface.c

diff --git a/src/plugins/linux-cp/lcp_interface.c b/src/plugins/linux-cp/lcp_interface.c
index bcd8ac7..be73372 100644 (file)
--- a/src/plugins/linux-cp/lcp_interface.c
+++ b/src/plugins/linux-cp/lcp_interface.c
@@ -981,6 +981,7 @@ lcp_itf_pair_create (u32 phy_sw_if_index, u8 *host_if_name,
        .host_namespace = 0,
       };
       ethernet_interface_t *ei;
+      u32 host_sw_mtu_size;
 
       if (host_if_type == LCP_ITF_HOST_TUN)
        args.tap_flags |= TAP_FLAG_TUN;
@@ -990,18 +991,28 @@ lcp_itf_pair_create (u32 phy_sw_if_index, u8 *host_if_name,
          mac_address_copy (&args.host_mac_addr, &ei->address.mac);
        }
 
-      if (sw->mtu[VNET_MTU_L3])
+      /*
+       * The TAP interface does copy forward the host MTU based on the VPP
+       * interface's L3 MTU, but it should also ensure that the VPP tap
+       * interface has an MTU that is greater-or-equal to those. Considering
+       * users can set the interfaces at runtime (set interface mtu packet ...)
+       * ensure that the tap MTU is large enough, taking the VPP interface L3
+       * if it's set, and otherwise a sensible default.
+       */
+      host_sw_mtu_size = sw->mtu[VNET_MTU_L3];
+      if (host_sw_mtu_size)
        {
          args.host_mtu_set = 1;
-         args.host_mtu_size = sw->mtu[VNET_MTU_L3];
+         args.host_mtu_size = host_sw_mtu_size;
        }
+      else
+       host_sw_mtu_size = ETHERNET_MAX_PACKET_BYTES;
 
       if (ns && ns[0] != 0)
        args.host_namespace = ns;
 
       vm = vlib_get_main ();
       tap_create_if (vm, &args);
-
       if (args.rv < 0)
        {
          LCP_ITF_PAIR_ERR ("pair_create: could not create tap, retval:%d",
@@ -1009,20 +1020,7 @@ lcp_itf_pair_create (u32 phy_sw_if_index, u8 *host_if_name,
          return args.rv;
        }
 
-      /*
-       * The TAP interface does copy forward the host MTU based on the VPP
-       * interface's L3 MTU, but it should also ensure that the VPP tap
-       * interface has an MTU that is greater-or-equal to those. Considering
-       * users can set the interfaces at runtime (set interface mtu packet ...)
-       * ensure that the tap MTU is large enough, taking the VPP interface L3
-       * if it's set, and otherwise a sensible default.
-       */
-      if (sw->mtu[VNET_MTU_L3])
-       vnet_sw_interface_set_mtu (vnm, args.sw_if_index,
-                                  sw->mtu[VNET_MTU_L3]);
-      else
-       vnet_sw_interface_set_mtu (vnm, args.sw_if_index,
-                                  ETHERNET_MAX_PACKET_BYTES);
+      vnet_sw_interface_set_mtu (vnm, args.sw_if_index, host_sw_mtu_size);
 
       /*
        * get the hw and ethernet of the tap
@@ -1068,7 +1066,7 @@ lcp_itf_pair_create (u32 phy_sw_if_index, u8 *host_if_name,
    * The TAP is shared by many interfaces, always keep it up.
    * This controls whether the host can RX/TX.
    */
-
+  sw = vnet_get_sw_interface (vnm, phy_sw_if_index);
   lip = lcp_itf_pair_get (lcp_itf_pair_find_by_vif (vif_index));
   LCP_ITF_PAIR_INFO ("pair create: %U sw-flags %u hw-flags %u",
                     format_lcp_itf_pair, lip, sw->flags, hw->flags);