CA-115557: networkd: implement enic workaround

When the enic workaround needs to be applied (according to the check
implemented in the previous commit), then when asked to add an interface to a
bridge, create a VLAN0 device for the given interface, and add that to the
bridge instead. This applies to bonded interfaces as well as individual ones
(we simply add the VLAN0 device on top of the bond device).

Also, in Interface.make_config, we need to take care to configure both the base
device as well as the VLAN0 device with the same parameters.

Finally, when destroying a bridge with a VLAN0 bond, we need to destroy the
bond device as well.

Signed-off-by: Rob Hoes <[email protected]>

Author: robhoes

networkd/network_server.ml

@@ -364,6 +364,17 @@ module Interface = struct
 				end else
 					config
 			in
+			let config =
+				if need_enic_workaround () then
+					List.fold_left (fun accu (name, interface) ->
+						if (Sysfs.is_physical name && Linux_bonding.get_bond_master_of name = None) || Linux_bonding.is_bond_device name then
+							(name, interface) :: (Ip.vlan_name name 0, interface) :: accu
+						else
+							(name, interface) :: accu
+					) [] config
+				else
+					config
+			in
 			debug "** Configuring the following interfaces: %s" (String.concat ", " (List.map (fun (name, _) -> name) config));
 			let exec f = if conservative then (try f () with _ -> ()) else f () in
 			List.iter (function (name, ({ipv4_conf; ipv4_gateway; ipv6_conf; ipv6_gateway; ipv4_routes; dns=nameservers,domains; mtu;
@@ -539,8 +550,14 @@ module Bridge = struct
 						Interface.bring_down () dbg ~name:dev;
 						if Linux_bonding.is_bond_device dev then
 							Linux_bonding.remove_bond_master dev;
-						if String.startswith "eth" dev && String.contains dev '.' then
-							ignore (Ip.destroy_vlan dev)
+						if (String.startswith "eth" dev || String.startswith "bond" dev) && String.contains dev '.' then begin
+							ignore (Ip.destroy_vlan dev);
+							let n = String.length dev in
+							if String.sub dev (n - 2) 2 = ".0" && need_enic_workaround () then
+								let vlan_base = String.sub dev 0 (n - 2) in
+								if Linux_bonding.is_bond_device vlan_base then
+									Linux_bonding.remove_bond_master (String.sub dev 0 (n - 2))
+						end;
 					) ifs;
 					Interface.set_ipv4_conf () dbg ~name ~conf:None4;
 					ignore (Brctl.destroy_bridge name)
@@ -643,10 +660,9 @@ module Bridge = struct
 							name bridge
 				end
 			| Bridge ->
-				if List.length interfaces = 1 then begin
-					List.iter (fun name -> Interface.bring_up () dbg ~name) interfaces;
-					ignore (Brctl.create_port bridge name)
-				end else begin
+				if List.length interfaces = 1 then
+					List.iter (fun name -> Interface.bring_up () dbg ~name) interfaces
+				else begin
 					if not (List.mem name (Sysfs.bridge_to_interfaces bridge)) then begin
 						Linux_bonding.add_bond_master name;
 						let bond_properties =
@@ -662,9 +678,16 @@ module Bridge = struct
 							| None -> warn "No MAC address specified for the bond"
 						end
 					end;
-					Interface.bring_up () dbg ~name;
+					Interface.bring_up () dbg ~name
+				end;
+				if need_enic_workaround () then begin
+					debug "Applying enic workaround: adding VLAN0 device to bridge";
+					Ip.create_vlan name 0;
+					let vlan0 = Ip.vlan_name name 0 in
+					Interface.bring_up () dbg ~name:vlan0;
+					ignore (Brctl.create_port bridge vlan0)
+				end else
 					ignore (Brctl.create_port bridge name)
-				end
 		) ()
 
 	let remove_port _ dbg ~bridge ~name =