commit 1cd0e5dd533f4209dde453eaa43215e52cd42985
author Damjan Marion <damarion@cisco.com> Mon Jan 17 14:49:17 2022 +0100
committer Ole Tr�an <otroan@employees.org> Tue Jan 18 13:20:21 2022 +0000
tree 88ed4b47252cfe27c13ac0f85a6cfc86a7052d5b
parent 49378f206b8e780a898e632f7dd8db912b9b118e

vnet: distinguish between max_frame_size and MTU

Type: improvement
Change-Id: I3659de6599f402c92e3855e3bf0e5e3388f2bea0
Signed-off-by: Damjan Marion <damarion@cisco.com>

src/vnet/ethernet/ethernet.h

diff --git a/src/vnet/ethernet/ethernet.h b/src/vnet/ethernet/ethernet.h
index b6adeb6..858400d 100644
--- a/src/vnet/ethernet/ethernet.h
+++ b/src/vnet/ethernet/ethernet.h
@@ -133,8 +133,8 @@
   /* ethernet interface flags change */
   ethernet_flag_change_function_t *flag_change;
 
-  /* set MTU callback */
-  vnet_interface_set_mtu_function_t *set_mtu;
+  /* set Max Frame Size callback */
+  vnet_interface_set_max_frame_size_function_t *set_max_frame_size;
 } vnet_eth_if_callbacks_t;
 
 #define ETHERNET_MIN_PACKET_BYTES  64
@@ -576,6 +576,8 @@
 {
   u32 dev_class_index;
   u32 dev_instance;
+  u16 max_frame_size;
+  u16 frame_overhead;
   vnet_eth_if_callbacks_t cb;
   const u8 *address;
 } vnet_eth_interface_registration_t;

src/vnet/ethernet/interface.c

diff --git a/src/vnet/ethernet/interface.c b/src/vnet/ethernet/interface.c
index bac8822..a0ad798 100644
--- a/src/vnet/ethernet/interface.c
+++ b/src/vnet/ethernet/interface.c
@@ -311,15 +311,18 @@
 }
 
 static clib_error_t *
-ethernet_set_mtu (vnet_main_t *vnm, vnet_hw_interface_t *hi, u32 mtu)
+ethernet_set_max_frame_size (vnet_main_t *vnm, vnet_hw_interface_t *hi,
+			     u32 frame_size)
 {
   ethernet_interface_t *ei =
     pool_elt_at_index (ethernet_main.interfaces, hi->hw_instance);
 
-  if (ei->cb.set_mtu)
-    return ei->cb.set_mtu (vnm, hi, mtu);
+  if (ei->cb.set_max_frame_size)
+    return ei->cb.set_max_frame_size (vnm, hi, frame_size);
 
-  return 0;
+  return vnet_error (
+    VNET_ERR_UNSUPPORTED,
+    "underlying driver doesn't support changing Max Frame Size");
 }
 
 /* *INDENT-OFF* */
@@ -333,7 +336,7 @@
   .build_rewrite = ethernet_build_rewrite,
   .update_adjacency = ethernet_update_adjacency,
   .mac_addr_change_function = ethernet_mac_change,
-  .set_mtu = ethernet_set_mtu,
+  .set_max_frame_size = ethernet_set_max_frame_size,
 };
 /* *INDENT-ON* */
 
@@ -378,10 +381,15 @@
 
   ethernet_setup_node (vnm->vlib_main, hi->output_node_index);
 
-  hi->min_packet_bytes = hi->min_supported_packet_bytes =
-    ETHERNET_MIN_PACKET_BYTES;
-  hi->max_supported_packet_bytes = ETHERNET_MAX_PACKET_BYTES;
-  hi->max_packet_bytes = em->default_mtu;
+  hi->min_frame_size = ETHERNET_MIN_PACKET_BYTES;
+  hi->frame_overhead =
+    r->frame_overhead ?
+      r->max_frame_size :
+      sizeof (ethernet_header_t) + 2 * sizeof (ethernet_vlan_header_t);
+  hi->max_frame_size = r->max_frame_size ?
+			 r->max_frame_size :
+			 ethernet_main.default_mtu + hi->frame_overhead;
+  ;
 
   /* Default ethernet MTU, 9000 unless set by ethernet_config see below */
   vnet_sw_interface_set_mtu (vnm, hi->sw_if_index, em->default_mtu);