meta-google: gbmc-bridge: Terminate DHCP after reachable

We don't want to continue running DHCP after a machine is ready to serve
traffic. We will only run the DHCP process for a short amount of time if
we can determine that the BMC can reach network services because it was
already correctly configured.

Change-Id: Ie79e0582718af88a4a170b2a77beebfbadd5d0af
Signed-off-by: William A. Kennington III <wak@google.com>

4 files changed, 53 insertions, 0 deletions

diff --git a/meta-google/recipes-google/networking/gbmc-bridge.bb b/meta-google/recipes-google/networking/gbmc-bridge.bb
index bc3b51367f..57f78ea4ac 100644
--- a/meta-google/recipes-google/networking/gbmc-bridge.bb
+++ b/meta-google/recipes-google/networking/gbmc-bridge.bb
@@ -22,6 +22,8 @@ SRC_URI += " \
   file://gbmc-br-nft.sh \
   file://gbmc-br-dhcp.sh \
   file://gbmc-br-dhcp.service \
+  file://gbmc-br-dhcp-term.sh \
+  file://gbmc-br-dhcp-term.service \
   "
 
 FILES:${PN}:append = " \
@@ -43,6 +45,7 @@ RDEPENDS:${PN}:append = " \
 SYSTEMD_SERVICE:${PN} += " \
   gbmc-br-ensure-ra.service \
   gbmc-br-dhcp.service \
+  gbmc-br-dhcp-term.service \
   "
 
 GBMC_BR_MAC_ADDR ?= ""
@@ -101,9 +104,11 @@ do_install() {
   install -d -m0755 ${D}${libexecdir}
   install -m0755 ${WORKDIR}/gbmc-br-ensure-ra.sh ${D}${libexecdir}/
   install -m0755 ${WORKDIR}/gbmc-br-dhcp.sh ${D}${libexecdir}/
+  install -m0755 ${WORKDIR}/gbmc-br-dhcp-term.sh ${D}${libexecdir}/
   install -d -m0755 ${D}${systemd_system_unitdir}
   install -m0644 ${WORKDIR}/gbmc-br-ensure-ra.service ${D}${systemd_system_unitdir}/
   install -m0644 ${WORKDIR}/gbmc-br-dhcp.service ${D}${systemd_system_unitdir}/
+  install -m0644 ${WORKDIR}/gbmc-br-dhcp-term.service ${D}${systemd_system_unitdir}/
 }
 
 do_rm_work:prepend() {
diff --git a/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp-term.service b/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp-term.service
new file mode 100644
index 0000000000..1a60545b0b
--- /dev/null
+++ b/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp-term.service
@@ -0,0 +1,13 @@
+[Unit]
+Description=gBMC DHCP Client terminator
+After=network.target
+StartLimitIntervalSec=10
+StartLimitBurst=3
+
+[Service]
+Restart=on-failure
+RestartSec=5
+ExecStart=/usr/libexec/gbmc-br-dhcp-term.sh
+
+[Install]
+WantedBy=multi-user.target
diff --git a/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp-term.sh b/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp-term.sh
new file mode 100644
index 0000000000..29fbbdeda5
--- /dev/null
+++ b/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp-term.sh
@@ -0,0 +1,31 @@
+#!/bin/bash
+# Copyright 2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Wait until a well known service is network available
+echo "Waiting for network reachability" >&2
+while ! ping -c 1 -W 1 2001:4860:4860::8888 >/dev/null 2>&1; do
+  sleep 1
+done
+wait_min=5
+echo "Network is reachable, waiting $wait_min minutes" >&2
+# Wait 5 minutes for any potential DHCP that hasn't landed yet
+sleep $((60 * wait_min))
+# If the DHCP configuration process is running, wait for it to finish
+if pid="$(cat /run/gbmc-br-dhcp.pid 2>/dev/null)"; then
+  echo "DHCP still running ($pid), waiting" >&2
+  wait "$pid"
+fi
+echo "Stopping DHCP processing" >&2
+systemctl stop --no-block gbmc-br-dhcp
diff --git a/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp.sh b/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp.sh
index 1a6c71af1b..19fa7b1010 100644
--- a/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp.sh
+++ b/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp.sh
@@ -37,6 +37,10 @@ gbmc_br_dhcp_run_hooks() {
 # shellcheck disable=SC1091
 source /usr/share/network/lib.sh || exit
 
+# Write out the current PID and cleanup when complete
+trap 'rm -f /run/gbmc-br-dhcp.pid' EXIT
+echo "$$" >/run/gbmc-br-dhcp.pid
+
 if [ "$1" = bound ]; then
   # Variable is from the environment via udhcpc6
   # shellcheck disable=SC2154