examples/gnrc_border_router: add option to re-use existing TAP interface

RIOT-OS · Nov 2, 2022 · cc2acd9 · cc2acd9
1 parent e802203
commit cc2acd9
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Showing 4 changed files with 24 additions and 8 deletions.
diff --git a/dist/tools/zep_dispatch/start_network.sh b/dist/tools/zep_dispatch/start_network.sh
@@ -25,7 +25,9 @@ remove_tap() {
 
 cleanup() {
     echo "Cleaning up..."
-    remove_tap
+    if [ "${CREATE_TAP}" -eq 1 ]; then
+        remove_tap
+    fi
     if [ -n "${UHCPD_PID}" ]; then
         kill "${UHCPD_PID}"
     fi
@@ -64,6 +66,13 @@ start_zep_dispatch() {
     ZEP_DISPATCH_PID=$!
 }
 
+if [ "$1" = "-c" ] || [ "$1" = "--create-tap" ]; then
+    CREATE_TAP=1
+    shift 1
+else
+    CREATE_TAP=0
+fi
+
 if [ "$1" = "-d" ] || [ "$1" = "--use-dhcpv6" ]; then
     USE_DHCPV6=1
     shift 1
@@ -101,7 +110,9 @@ for TAP in "$@"; do :; done
 
 trap "cleanup" INT QUIT TERM EXIT
 
-create_tap
+if [ ${CREATE_TAP} -eq 1 ]; then
+    create_tap
+fi
 
 if [ ${USE_ZEP_DISPATCH} -eq 1 ]; then
     start_zep_dispatch

diff --git a/examples/gnrc_border_router/Makefile b/examples/gnrc_border_router/Makefile
@@ -11,8 +11,8 @@ RIOTBASE ?= $(CURDIR)/../..
 UPLINK ?= ethos
 
 # Check if the selected Uplink is valid
-ifeq (,$(filter ethos slip cdc-ecm wifi ethernet,$(UPLINK)))
-  $(error Supported uplinks are `ethos`, `slip`, `cdc-ecm`, `ethernet` and `wifi`)
+ifeq (,$(filter ethos slip cdc-ecm wifi ethernet tap,$(UPLINK)))
+  $(error Supported uplinks are `ethos`, `tap`, `slip`, `cdc-ecm`, `ethernet` and `wifi`)
 endif
 
 # Set the SSID and password of your WiFi network here

diff --git a/examples/gnrc_border_router/Makefile.native.conf b/examples/gnrc_border_router/Makefile.native.conf
@@ -9,10 +9,14 @@ CFLAGS += -DASYNC_READ_NUMOF=$(shell expr $(ZEP_DEVICES) + 1)
 # Set CFLAGS if not being set via Kconfig
 CFLAGS += $(if $(CONFIG_KCONFIG_MODULE_DHCPV6),,-DCONFIG_DHCPV6_CLIENT_PFX_LEASE_MAX=$(ZEP_DEVICES))
 
-ifeq (dhcpv6,$(PREFIX_CONF))
-  FLAGS_EXTRAS += --use-dhcpv6
-else ifeq (auto_subnets,$(PREFIX_CONF))
-  FLAGS_EXTRAS += --use-radvd
+# create a new TAP interface if not re-using an existing one
+ifneq (tap,$(UPLINK))
+  FLAGS_EXTRAS += --create-tap
+  ifeq (dhcpv6,$(PREFIX_CONF))
+    FLAGS_EXTRAS += --use-dhcpv6
+  else ifeq (auto_subnets,$(PREFIX_CONF))
+    FLAGS_EXTRAS += --use-radvd
+  endif
 endif
 
 # enable the ZEP dispatcher

diff --git a/examples/gnrc_border_router/README.md b/examples/gnrc_border_router/README.md
@@ -26,6 +26,7 @@ For `native` the host-facing [`netdev_tap`](https://doc.riot-os.org/netdev__tap_
 is configured, providing connectivity via a TAP interface to the RIOT instance.
 On the node-facing side [`socket_zep`](https://doc.riot-os.org/group__drivers__socket__zep.html)
 is used to simulate a IEEE 802.15.4 network.
+Set `UPLINK=tap` to re-use an existing TAP interface instead of creating a new one.
 
 To select an uplink, set the UPLINK environment variable. For instance, use `UPLINK=slip`
 for a SLIP uplink.