From b294805a2295e91844144d2af1a2f70e16d3e4ec Mon Sep 17 00:00:00 2001
From: Michael Prokop <mika@grml.org>
Date: Wed, 27 May 2020 10:56:43 +0200
Subject: [PATCH] Provide more detailed network information

* Display information about all configured IP addresses
  (excluding localhost)

* Display SSH information whenever sshd process is running,
  since boot option ssh might isn't strictly necessary
  (boot option services=ssh or a custom netscript might
  start it as well as a customized Grml ISO)

* Display zeroconf hostname information (when service
  avahi-daemon is running and avahi-resolve-address is
  available)

Closes: grml/grml-quickconfig#1
---
 quickconfig/002-ipaddr.sh | 83 +++++++++++++++++++++++++++++++++++++----------
 1 file changed, 66 insertions(+), 17 deletions(-)

diff --git a/quickconfig/002-ipaddr.sh b/quickconfig/002-ipaddr.sh
index c7cc3c8..41248bb 100644
--- a/quickconfig/002-ipaddr.sh
+++ b/quickconfig/002-ipaddr.sh
@@ -1,26 +1,75 @@
-ROOTPWD=$(grep -Eo '\<ssh=[^ ]+' /proc/cmdline || true)
+# always try to gather network information
+LOCAL_IF=$(ip -o route show | sed -nre '/^default /s/^default .*dev ([^ ]+).*/\1/p' | head -1)
+if [ -n "${LOCAL_IF}" ] ; then
+  IPADDR=$(ip -o addr show "${LOCAL_IF}" | grep ' inet ' | head -n 1 | sed -e 's/.*inet \([^ ]*\) .*/\1/' -e 's/\/.*//')
+fi
 
-if [ "$ROOTPWD" ]; then
-  ROOTPWD=${ROOTPWD#*=}
+LOCAL_IF6=$(ip -6 -o route show | sed -nre '/^default /s/^default .*dev ([^ ]+).*/\1/p' | head -1)
+if [ -n "${LOCAL_IF6}" ] ; then
+  IPADDR6=$(ip -6 -o addr show "${LOCAL_IF6}" | grep ' inet6 ' | head -n 1 | sed -e 's/.*inet6 \([^ ]*\) .*/\1/' -e 's/\/.*//')
+fi
 
-  USER=$(getent passwd 1000 | cut -d: -f1)
-  [ -n "$USER" ] || USER="grml"
+# ssh / password information
+SSHD_PID=$(pgrep sshd || true)
+SSH_OPTION=$(grep -Eo '\<ssh=[^ ]+' /proc/cmdline || true)
+PWD_OPTION=$(grep -Eo '\<passwd=[^ ]+' /proc/cmdline || true)
 
-  LOCAL_IF=$(ip -o route show | sed -nre '/^default /s/^default .*dev ([^ ]+).*/\1/p' | head -1)
-  if [ -n "$LOCAL_IF" ] ; then
-    IPADDR=$(ip -o addr show $LOCAL_IF | grep ' inet ' | head -n 1 | sed -e 's/.*inet \([^ ]*\) .*/\1/' -e 's/\/.*//')
-  fi
+if [ -n "${SSHD_PID:-}" ] ; then
+  LINE+="print_line 'You can connect with SSH to: ${IPADDR:-} ${IPADDR6:-} ${AVAHI_INFO:-}';"
+fi
+
+USER=$(getent passwd 1000 | cut -d: -f1)
+[ -n "${USER:-}" ] || USER="grml"
+if [ -n "${PWD_OPTION:-}" ] ; then
+  PWD_OPTION=${PWD_OPTION#*=}
+  LINE+="print_line 'The password for user root/${USER} is: ${PWD_OPTION:-}';"
+elif [ -n "${SSH_OPTION:-}" ] ; then
+  SSH_OPTION=${SSH_OPTION#*=}
+  LINE+="print_line 'The password for user root/${USER} is: ${SSH_OPTION:-}';"
+fi
 
-  LOCAL_IF6=$(ip -6 -o route show | sed -nre '/^default /s/^default .*dev ([^ ]+).*/\1/p' | head -1)
-  if [ -n "$LOCAL_IF6" ] ; then
-    IPADDR6=$(ip -6 -o addr show $LOCAL_IF6 | grep ' inet6 ' | head -n 1 | sed -e 's/.*inet6 \([^ ]*\) .*/\1/' -e 's/\/.*//')
+LINE+="print_line 'Network information:';"
+
+NETINFO_PRESENT=false
+
+# zeroconf information
+AVAHI_PID=$(pgrep avahi-daemon || true)
+if [ -n "${AVAHI_PID:-}" ] && [ -x "$(which avahi-resolve-address)" ] && [ -n "${IPADDR:-}" ] ; then
+  AVAHI_INFO="$(avahi-resolve-address "${IPADDR}" 2>/dev/null | awk '{print $2}')"
+  if [ -n "${AVAHI_INFO:-}" ] ; then
+    LINE+="print_line '-> Hostname:   ${AVAHI_INFO}';"
+    NETINFO_PRESENT=true
   fi
+fi
 
-  LINE='print_line "You can connect with SSH to: $IPADDR $IPADDR6";
-print_line "The password for user root/$USER is: $ROOTPWD";
-  print_delim;
-'
+# list all non-localhost IP addresses
+declare -a IP_LIST
+for ip in $(
+  {
+    ip -4 -o addr show | grep ' inet '  | sed -e 's/.*inet \([^ ]*\) .*/\1/'  -e 's/\/.*//'
+    ip -6 -o addr show | grep ' inet6 ' | sed -e 's/.*inet6 \([^ ]*\) .*/\1/' -e 's/\/.*//'
+  } | sort -u) ; do
+  case "${ip}" in
+    127.0.0.*)
+      continue
+      ;;
+    ::1)
+      continue
+      ;;
+    fe80::*)
+      continue
+      ;;
+    *)
+      LINE+="print_line '-> IP address: $ip';"
+      NETINFO_PRESENT=true
+      ;;
+  esac
+done
+
+if [ "${NETINFO_PRESENT}" = "false" ] ; then
+  LINE+="print_line '-> network seems to be unconfigured (yet)';"
 fi
 
-display_entry() { return 0; }
+LINE+='print_delim;'
 
+display_entry() { return 0; }
-- 
2.1.4