setup: support setting up AP with Network Manager

setup/pi/configure-ap.sh

@@ -6,8 +6,9 @@ function log_progress () {
   if declare -F setup_progress > /dev/null
   then
     setup_progress "configure-ap: $1"
+  else
+    echo "configure-ap: $1"
   fi
-  echo "configure-ap: $1"
 }
 
 if [ -z "${AP_SSID+x}" ]
@@ -22,6 +23,91 @@ then
   exit 1
 fi
 
+function nm_get_wifi_client_device () {
+  for i in {1..5}
+  do
+    WLAN="$(nmcli -t -f TYPE,DEVICE c show --active | grep 802-11-wireless | grep -v ":ap0$" | cut -c 17-)"
+    if [ -n "$WLAN" ]
+    then
+      break;
+    fi
+    log_progress "Waiting for wifi interface to come back up"
+    sleep 5
+  done
+
+  [ -n "$WLAN" ] && return 0
+
+  log_progress "Couldn't determine wifi client device"
+  nmcli c show
+  return 1
+}
+
+function nm_add_ap () {
+  nm_get_wifi_client_device || return 1
+
+  if ! iw dev ap0 info &> /dev/null
+  then
+    # create additional virtual interface for the wifi device
+    iw dev "$WLAN" interface add ap0 type __ap || return 1
+  fi
+
+  # turn off power savings for both interfaces since they use
+  # the same underlying hardware, and we don't want one to go
+  # into power save mode just because the other is idle
+  iw "$WLAN" set power_save off || return 1
+  iw ap0 set power_save off || return 1
+
+  # set up access point on the virtual interface using networkmanager
+  nmcli con delete TESLAUSB_AP &> /dev/null || true
+  nmcli con add type wifi ifname ap0 mode ap con-name TESLAUSB_AP ssid "$AP_SSID" || return 1
+  # don't set band and channel, because that is controlled by the $WLAN interface
+  #nmcli con modify TESLAUSB_AP 802-11-wireless.band bg
+  #nmcli con modify TESLAUSB_AP 802-11-wireless.channel 6
+  nmcli con modify TESLAUSB_AP 802-11-wireless-security.key-mgmt wpa-psk || return 1
+  nmcli con modify TESLAUSB_AP 802-11-wireless-security.psk "$AP_PASS" || return 1
+  IP=${AP_IP:-"192.168.66.1"}
+  nmcli con modify TESLAUSB_AP ipv4.addr "$IP/24" || return 1
+  nmcli con modify TESLAUSB_AP ipv4.method shared || return 1
+  nmcli con modify TESLAUSB_AP ipv6.method disabled || return 1
+  cat > /etc/network/if-up.d/teslausb-ap << EOF
+#!/bin/bash
+
+if [ "\$IFACE" = "$WLAN" ]
+then
+  iw dev $WLAN interface add ap0 type __ap
+  iw "$WLAN" set power_save off
+  iw ap0 set power_save off
+  nmcli con up TESLAUSB_AP
+fi
+
+EOF
+  chmod a+x /etc/network/if-up.d/teslausb-ap || return 1
+}
+
+
+if systemctl --quiet is-enabled NetworkManager.service
+then
+  # force-install iw because otherwise it will get autoremoved when
+  # alsa-utils is removed later
+  apt-get -y --force-yes install iw || return 1
+  if ! nm_add_ap
+  then
+    # Network Manager won't allow adding connections when started with a
+    # read-only root fs, even if the root fs is not writeable, so try
+    # again after restarting Network Manager
+    log_progress "Retrying after restarting Network Manager"
+    systemctl restart NetworkManager.service
+    if ! nm_add_ap
+    then
+      log_progress "STOP: Failed to configure AP"
+      exit 1
+    fi
+  fi
+  log_progress "AP configured"
+  exit 0
+fi
+
+
 if [ ! -e /etc/wpa_supplicant/wpa_supplicant.conf ]
 then
   log_progress "No wpa_supplicant, skipping AP setup."

setup/pi/make-root-fs-readonly.sh

@@ -98,6 +98,14 @@ then
   sed -i 's/Before=.*/After=mutable.mount/' /lib/systemd/system/fake-hwclock.service
 fi
 
+if [ -d /var/lib/NetworkManager/ ] && [ -n "$AP_SSID" ]
+then
+  log_progress "Moving /var/lib/NetworkManager to mutable"
+  mkdir -p /mutable/var/lib/
+  mv /var/lib/NetworkManager /mutable/var/lib/
+  ln -s /mutable/var/lib/NetworkManager/ /var/lib/NetworkManager
+fi
+
 # Create a configs directory for others to use
 if [ ! -e "/mutable/configs" ]
 then