host info updates

[distro-setup] / dynamic-ip-update

diff --git a/dynamic-ip-update b/dynamic-ip-update
index 6c12ccb60fa0d4531883840b5037d8701d2c4779..12726ae37335f80e0d0d2acdb6eca9d50b3d2ee2 100755 (executable)
--- a/dynamic-ip-update
+++ b/dynamic-ip-update
@@ -1,4 +1,25 @@
 #!/bin/bash
+# I, Ian Kelling, follow the GNU license recommendations at
+# https://www.gnu.org/licenses/license-recommendations.en.html. They
+# recommend that small programs, < 300 lines, be licensed under the
+# Apache License 2.0. This file contains or is part of one or more small
+# programs. If a small program grows beyond 300 lines, I plan to switch
+# its license to GPL.
+
+# Copyright 2024 Ian Kelling
+
+# 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.
+
 
 set -e; . /usr/local/lib/bash-bear; set +e
 [[ $EUID == 0 ]] || exec sudo -E "${BASH_SOURCE[0]}" "$@"
@@ -67,7 +88,6 @@ main() {
   case $gateway in
     10.2.0.1)
       dyndomain=b8.nz
-      dynhost=i.b8.nz
       ;;
     *)
       return 0
@@ -95,14 +115,14 @@ main() {
 
 
   if $athome; then
-    if ! cur4="$(dig +short $dynhost @iankelling.org | tail -1)"; then
+    if ! cur4="$(dig +short $dyndomain @iankelling.org | tail -1)"; then
       if [[ ! $INVOCATION_ID ]]; then
         echo "$0: dig failed. internet looks down. giving up"
       fi
       return 0
     fi
-    if ip4=$(curl -s4 https://iankelling.org/cgi/pubip); then
-      if $force || [[ $cur4 && $ip4 && $cur4 != $ip4 ]]; then
+    if ip4=$(curl --connect-timeout 10 -s4 https://iankelling.org/cgi/pubip); then
+      if $force || [[ $cur4 && $ip4 && $cur4 != "$ip4" ]]; then
         up4=true # update ipv4
       fi
     fi
@@ -113,14 +133,14 @@ main() {
 
   up6=false
 
-  out6=$(curl -s6 https://iankelling.org/cgi/pubip) ||: # failure allowed if we have no ipv6
+  out6=$(curl --connect-timeout 10 -s6 https://iankelling.org/cgi/pubip) ||: # failure allowed if we have no ipv6
 
   if [[ $out6 ]]; then
     dev=$(ip -o a show to $out6 | awk '{print $2}')
     # we use slaac with privacy extension, so get our less private more permanent address
     mac=$(cat /sys/class/net/$dev/address)
 
-    IFS=: read -a f <<<$mac; set -- ${f[@]}
+    IFS=: read -ra f <<<$mac; set -- ${f[@]}
     ip6=${out6%:*:*:*:*}:$(printf %x $((0x$1 + 2)))$2:$3'ff:fe'$4:$5$6
     # in case we aren't using slaac
     if ! ip a | grep "^ *inet6 $ip6/" &>/dev/null; then
@@ -128,10 +148,16 @@ main() {
     fi
   fi
 
-  if $force || [[ $cur6 != $ip6 ]]; then
+  if $force || [[ $cur6 != "$ip6" ]]; then
     up6=true
   fi
 
+  # if we failed to get our ipv6 addr, we probably have ipv6
+  # connectivity problem.
+  if [[ ! $ip6 ]]; then
+    ip_arg=-4
+  fi
+
   if ! $up4 && ! $up6; then
     return 0
   fi
@@ -140,16 +166,14 @@ main() {
   # "${SSH_CLIENT%% *}
   # to update bind if needed.
 
-  f=$(mktemp)
-  cat >>$f <<EOF
+  tmpf=$(mktemp)
+  cat >>$tmpf <<EOF
 server iankelling.org
 zone b8.nz
 EOF
 
   if $up4; then
-    cat >>$f <<EOF
-update delete $dynhost. A
-update add $dynhost. 300 A $ip4
+    cat >>$tmpf <<EOF
 update delete $dyndomain. A
 update add $dyndomain. 300 A $ip4
 EOF
@@ -157,31 +181,32 @@ EOF
 
   if $up6; then
     if [[ $ip6 ]]; then
-      cat >>$f <<EOF
+      cat >>$tmpf <<EOF
 update delete $fqdn. AAAA
 update add $fqdn. 60 AAAA $ip6
 EOF
     else
-      cat >>$f <<EOF
+      cat >>$tmpf <<EOF
 update delete $fqdn. AAAA
 EOF
     fi
   fi
 
-  cat >>$f <<EOF
+  cat >>$tmpf <<EOF
 show
 send
 answer
 quit
 EOF
 
-  nsupdate -k /p/c/machine_specific/vps/filesystem/etc/bind/Kb8.nz.*.private <$f || nsupdate_fails=$((nsupdate_fails + 1))
-  sed -i 's/^server .*/server bk.b8.nz/' $f
-  nsupdate -k /p/c/machine_specific/vps/filesystem/etc/bind/Kb8.nz.*.private <$f  || nsupdate_fails=$((nsupdate_fails + 1))
+  chronic nsupdate $ip_arg -k /p/c/machine_specific/vps/filesystem/etc/bind/Kb8.nz.*.private <$tmpf || nsupdate_fails=$((nsupdate_fails + 1))
+  sed -i 's/^server .*/server bk.b8.nz/' $tmpf
+  chronic nsupdate $ip_arg -k /p/c/machine_specific/vps/filesystem/etc/bind/Kb8.nz.*.private <$tmpf  || nsupdate_fails=$((nsupdate_fails + 1))
   if (( nsupdate_fails > nsupdate_fail_limit )); then
     echo error: nsupdate is persistently failing >&2
     exit 1
   fi
+  rm -f $tmpf
 }
 
 loop-main() {
@@ -213,7 +238,7 @@ exit 0
 
 
 #   f=key.b8.nz
-#   cat >$f <<EOF
+#   cat >$tmpf <<EOF
 # key b8.nz. {
 # algorithm HMAC-SHA512;
 # secret "$(awk '$1 == "Key:" {print $2}' Kb8.nz.*.private)";