meta-google: gbmc-bridge: Implement DHCP

This makes it possible for a BMC to acquire a public address via DHCP
provisioning.

None of the update processes are included yet.

Change-Id: I51ca2aa4859bcd2b9e909dd5a0d9e66cfbd648af
Signed-off-by: William A. Kennington III <wak@google.com>

6 files changed, 153 insertions, 1 deletions

diff --git a/meta-google/recipes-google/ncsi/files/gbmc-ncsi-br-pub-addr.sh.in b/meta-google/recipes-google/ncsi/files/gbmc-ncsi-br-pub-addr.sh.in
index 5adc41328..793403348 100644
--- a/meta-google/recipes-google/ncsi/files/gbmc-ncsi-br-pub-addr.sh.in
+++ b/meta-google/recipes-google/ncsi/files/gbmc-ncsi-br-pub-addr.sh.in
@@ -63,6 +63,8 @@ Destination=$stateless_pfx/76
 Type=unreachable
 Metric=1024
 EOF
+    # Delete DHCP configured addresses if we have a host published address
+    rm -f /etc/systemd/network/{00,}-bmc-gbmcbr.network.d/50-public.conf
   fi
 
   local file
diff --git a/meta-google/recipes-google/ncsi/files/gbmc-ncsi-clear-ip.sh.in b/meta-google/recipes-google/ncsi/files/gbmc-ncsi-clear-ip.sh.in
new file mode 100644
index 000000000..e17a5e200
--- /dev/null
+++ b/meta-google/recipes-google/ncsi/files/gbmc-ncsi-clear-ip.sh.in
@@ -0,0 +1,26 @@
+# Copyright 2021 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.
+
+[ -z "${gbmc_ncsi_clear_ip-}" ] || exit
+
+source /usr/libexec/ncsid_lib.sh || exit
+
+gbmc_ncsi_clear_ip_hook() {
+  UpdateIP xyz.openbmc_project.Network '@NCSI_IF@' '0.0.0.0' '0' || true
+  UpdateIP xyz.openbmc_project.Network '@NCSI_IF@' '::' '0' || true
+}
+
+GBMC_BR_DHCP_HOOKS+=(gbmc_ncsi_clear_ip_hook)
+
+gbmc_ncsi_clear_ip=1
diff --git a/meta-google/recipes-google/ncsi/gbmc-ncsi-config.bb b/meta-google/recipes-google/ncsi/gbmc-ncsi-config.bb
index 0074a3172..6e2582495 100644
--- a/meta-google/recipes-google/ncsi/gbmc-ncsi-config.bb
+++ b/meta-google/recipes-google/ncsi/gbmc-ncsi-config.bb
@@ -20,6 +20,7 @@ SRC_URI += " \
   file://gbmc-ncsi-br-pub-addr.sh.in \
   file://gbmc-ncsi-br-deprecated-ips.sh.in \
   file://gbmc-ncsi-set-nicenabled.service.in \
+  file://gbmc-ncsi-clear-ip.sh.in \
   "
 
 S = "${WORKDIR}"
@@ -36,6 +37,7 @@ RDEPENDS:${PN} += " \
   "
 
 FILES:${PN} += " \
+  ${datadir}/gbmc-br-dhcp \
   ${datadir}/gbmc-ip-monitor \
   ${systemd_unitdir} \
   "
@@ -105,6 +107,12 @@ do_install:append() {
     >${WORKDIR}/gbmc-ncsi-br-deprecated-ips.sh
   install -m644 ${WORKDIR}/gbmc-ncsi-br-deprecated-ips.sh $mondir
 
+  dhcpdir=${D}${datadir}/gbmc-br-dhcp/
+  install -d -m0755 $dhcpdir
+  sed "s,@NCSI_IF@,$if_name,g" ${WORKDIR}/gbmc-ncsi-clear-ip.sh.in \
+    >${WORKDIR}/gbmc-ncsi-clear-ip.sh
+  install -m644 ${WORKDIR}/gbmc-ncsi-clear-ip.sh $dhcpdir
+
   sed "s,@NCSI_IF@,$if_name,g" ${WORKDIR}/gbmc-ncsi-set-nicenabled.service.in \
     >${D}${systemd_system_unitdir}/gbmc-ncsi-set-nicenabled.service
 
diff --git a/meta-google/recipes-google/networking/gbmc-bridge.bb b/meta-google/recipes-google/networking/gbmc-bridge.bb
index dea14f00b..5f79d468a 100644
--- a/meta-google/recipes-google/networking/gbmc-bridge.bb
+++ b/meta-google/recipes-google/networking/gbmc-bridge.bb
@@ -20,6 +20,8 @@ SRC_URI += " \
   file://gbmc-br-ensure-ra.service \
   file://gbmc-br-gw-src.sh \
   file://gbmc-br-nft.sh \
+  file://gbmc-br-dhcp.sh \
+  file://gbmc-br-dhcp.service \
   "
 
 FILES:${PN}:append = " \
@@ -37,7 +39,10 @@ RDEPENDS:${PN}:append = " \
   ndisc6-rdisc6 \
   "
 
-SYSTEMD_SERVICE:${PN} += "gbmc-br-ensure-ra.service"
+SYSTEMD_SERVICE:${PN} += " \
+  gbmc-br-ensure-ra.service \
+  gbmc-br-dhcp.service \
+  "
 
 GBMC_BR_MAC_ADDR ?= ""
 
@@ -94,8 +99,10 @@ 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 -d -m0755 ${D}${systemd_system_unitdir}
   install -m0755 ${WORKDIR}/gbmc-br-ensure-ra.service ${D}${systemd_system_unitdir}/
+  install -m0755 ${WORKDIR}/gbmc-br-dhcp.service ${D}${systemd_system_unitdir}/
 }
 
 do_rm_work:prepend() {
diff --git a/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp.service b/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp.service
new file mode 100644
index 000000000..145f84b93
--- /dev/null
+++ b/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp.service
@@ -0,0 +1,13 @@
+[Unit]
+Description=gBMC DHCP Client
+After=network.target
+StartLimitIntervalSec=10
+StartLimitBurst=3
+
+[Service]
+Restart=always
+RestartSec=5
+ExecStart=/usr/bin/udhcpc6 -f -q -O bootfile_url -O bootfile_param -i gbmcbr -s /usr/libexec/gbmc-br-dhcp.sh
+
+[Install]
+WantedBy=multi-user.target
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
new file mode 100644
index 000000000..beccc8658
--- /dev/null
+++ b/meta-google/recipes-google/networking/gbmc-bridge/gbmc-br-dhcp.sh
@@ -0,0 +1,96 @@
+#!/bin/bash
+# Copyright 2021 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.
+
+# A list of functions which get executed for each bound DHCP lease.
+# These are configured by the files included below.
+GBMC_BR_DHCP_HOOKS=()
+
+# Load configurations from a known location in the filesystem to populate
+# hooks that are executed after each event.
+shopt -s nullglob
+for conf in /usr/share/gbmc-br-dhcp/*.sh; do
+  # SC doesn't like dynamic source loading
+  # shellcheck disable=SC1090
+  source "$conf"
+done
+
+gbmc_br_dhcp_run_hooks() {
+  local hook
+  for hook in "${GBMC_BR_DHCP_HOOKS[@]}"; do
+    "$hook" || continue
+  done
+}
+
+# SC can't find this path during repotest
+# shellcheck disable=SC1091
+source /usr/share/network/lib.sh || exit
+
+if [ "$1" = bound ]; then
+  # Variable is from the environment via udhcpc6
+  # shellcheck disable=SC2154
+  echo "DHCPv6(gbmcbr): $ipv6/128" >&2
+
+  pfx_bytes=()
+  ip_to_bytes pfx_bytes "$ipv6"
+  # Ensure we are a BMC and have a suffix nibble, the 0th index is reserved
+  if (( pfx_bytes[8] != 0xfd || pfx_bytes[9] & 0xf == 0 )); then
+    echo "Invalid address" >&2
+    exit
+  fi
+  # Ensure we don't have more than a /80 address
+  for (( i = 10; i < 16; ++i )); do
+    if (( pfx_bytes[i] != 0 )); then
+      echo "Invalid address" >&2
+      exit
+    fi
+  done
+
+  pfx="$(ip_bytes_to_str pfx_bytes)"
+  (( pfx_bytes[9] &= 0xf0 ))
+  stateless_pfx="$(ip_bytes_to_str pfx_bytes)"
+  read -r -d '' contents <<EOF
+[Network]
+Address=$pfx/128
+IPv6PrefixDelegation=yes
+[IPv6PrefixDelegation]
+RouterLifetimeSec=60
+[IPv6Prefix]
+Prefix=$stateless_pfx/80
+PreferredLifetimeSec=60
+ValidLifetimeSec=60
+[IPv6RoutePrefix]
+Route=$pfx/80
+LifetimeSec=60
+[Route]
+Destination=$stateless_pfx/76
+Type=unreachable
+Metric=1024
+EOF
+
+  for file in /etc/systemd/network/{00,}-bmc-gbmcbr.network.d/50-public.conf; do
+    mkdir -p "$(dirname "$file")"
+    printf '%s' "$contents" >"$file"
+  done
+
+  # Ensure that systemd-networkd performs a reconfiguration as it doesn't
+  # currently check the mtime of drop-in files.
+  touch -c /lib/systemd/network/*-bmc-gbmcbr.network
+
+  if [ "$(systemctl is-active systemd-networkd)" != 'inactive' ]; then
+    networkctl reload && networkctl reconfigure gbmcbr
+  fi
+
+  gbmc_br_dhcp_run_hooks
+fi