initial commit

without warranty of any kind, express or impliend

1 files changed, 95 insertions, 0 deletions

diff --git a/openwrt/config_generation.sh b/openwrt/config_generation.sh
new file mode 100644
index 0000000..c8e9bfa
--- /dev/null
+++ b/openwrt/config_generation.sh
@@ -0,0 +1,95 @@
+#!/bin/sh /etc/rc.common
+
+EXTRA_COMMANDS="apply commit"
+START=99
+
+_unregister_script() {
+    /etc/init.d/config_generation disable
+    rm /etc/init.d/config_generation
+}
+
+_rollback() {
+    rm -rf /overlay/upper.dead
+    mv /overlay/upper /overlay/upper.dead
+    # this should never fail, unless something *else* is also mucking
+    # with overlayfs state.
+    if mv -T /overlay/upper.prev /overlay/upper; then
+        rm -rf /overlay/upper.dead
+    else
+        echo "rollback failed, check /overlay/upper.dead and recover!" >&2
+        exit 1
+    fi
+}
+
+apply() {
+    if ! rm -rf /overlay/upper.prev/ \
+        || ! cp -al /overlay/upper/ /overlay/upper.prev/ \
+        || ! rm -rf /overlay/upper.prev/etc/ \
+        || ! cp -a /overlay/upper/etc/ /overlay/upper.prev/
+    then
+        echo "failed to snapshot old config"
+        rm -rf /overlay/upper.prev
+        exit 1
+    fi
+
+    if ! /etc/init.d/config_generation enable
+    then
+        echo "failed to schedule rollback"
+        rm -rf /overlay/upper.prev
+        exit 1
+    fi
+
+    # everything after this point may fail. if it does we'll simply roll back
+    # immediately and reboot.
+
+    trap 'reboot &' EXIT
+
+    log() {
+        printf "$LOG_FMT\n" "$*"
+    }
+
+    if ! (
+        set -e
+
+        @deploy_steps@
+    )
+    then
+        _rollback
+    fi
+}
+
+commit() {
+    if ! [ -e /overlay/upper.prev ]; then
+        exit 1
+    fi
+    touch /tmp/.abort-rollback
+}
+
+start() {
+    [ -d /overlay/upper.prev ] || {
+        _unregister_script
+        exit 0
+    }
+
+    local needs_rollback=true
+    local timeout=@rollback_timeout@
+
+    while [ $timeout -gt 0 ]; do
+        timeout=$(( timeout - 1 ))
+        [ -e /tmp/.abort-rollback ] && {
+            needs_rollback=false
+            rm /tmp/.abort-rollback
+            break
+        }
+        sleep 1
+    done
+
+    if $needs_rollback; then
+        _rollback
+        _unregister_script
+        reboot
+    else
+        rm -rf /overlay/upper.prev
+        _unregister_script
+    fi
+}