From 7937a74469c8b55a70855db6ee856ffed1205e31 Mon Sep 17 00:00:00 2001
From: hwdsl2 <hwdsl2@users.noreply.github.com>
Date: Fri, 9 Sep 2016 15:33:12 -0500
Subject: [PATCH] Improve IP detection

- Remove unneeded code for Amazon EC2
- Check IPs for correct format after each try
---
 vpnsetup.sh        | 18 ++++++++++--------
 vpnsetup_centos.sh | 18 ++++++++++--------
 2 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/vpnsetup.sh b/vpnsetup.sh
index f962f47..4599c81 100755
--- a/vpnsetup.sh
+++ b/vpnsetup.sh
@@ -119,22 +119,24 @@ EOF
 PUBLIC_IP=${VPN_PUBLIC_IP:-''}
 PRIVATE_IP=${VPN_PRIVATE_IP:-''}
 
-# In Amazon EC2, these two variables will be retrieved from metadata
-[ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(wget -t 3 -T 5 -qO- 'http://169.254.169.254/latest/meta-data/public-ipv4')
-[ -z "$PRIVATE_IP" ] && PRIVATE_IP=$(wget -t 3 -T 5 -qO- 'http://169.254.169.254/latest/meta-data/local-ipv4')
-
-# Try to find IPs for non-EC2 servers
+# Try to auto discover IPs of this server
 [ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(dig @resolver1.opendns.com -t A -4 myip.opendns.com +short)
-[ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://whatismyip.akamai.com)
-[ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://ipv4.icanhazip.com)
 [ -z "$PRIVATE_IP" ] && PRIVATE_IP=$(ip -4 route get 1 | awk '{print $NF;exit}')
-[ -z "$PRIVATE_IP" ] && PRIVATE_IP=$(ifconfig eth0 | grep -Eo 'inet (addr:)?([0-9]*\.){3}[0-9]*' | grep -Eo '([0-9]*\.){3}[0-9]*')
 
 # Check IPs for correct format
 IP_REGEX="^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"
+if ! printf %s "$PUBLIC_IP" | grep -Eq "$IP_REGEX"; then
+  PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://whatismyip.akamai.com)
+fi
+if ! printf %s "$PUBLIC_IP" | grep -Eq "$IP_REGEX"; then
+  PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://ipv4.icanhazip.com)
+fi
 if ! printf %s "$PUBLIC_IP" | grep -Eq "$IP_REGEX"; then
   exiterr "Cannot find valid public IP. Edit the script and manually enter IPs."
 fi
+if ! printf %s "$PRIVATE_IP" | grep -Eq "$IP_REGEX"; then
+  PRIVATE_IP=$(ifconfig eth0 | grep -Eo 'inet (addr:)?([0-9]*\.){3}[0-9]*' | grep -Eo '([0-9]*\.){3}[0-9]*')
+fi
 if ! printf %s "$PRIVATE_IP" | grep -Eq "$IP_REGEX"; then
   exiterr "Cannot find valid private IP. Edit the script and manually enter IPs."
 fi
diff --git a/vpnsetup_centos.sh b/vpnsetup_centos.sh
index ddea15a..0f8afaa 100755
--- a/vpnsetup_centos.sh
+++ b/vpnsetup_centos.sh
@@ -106,22 +106,24 @@ EOF
 PUBLIC_IP=${VPN_PUBLIC_IP:-''}
 PRIVATE_IP=${VPN_PRIVATE_IP:-''}
 
-# In Amazon EC2, these two variables will be retrieved from metadata
-[ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(wget -t 3 -T 5 -qO- 'http://169.254.169.254/latest/meta-data/public-ipv4')
-[ -z "$PRIVATE_IP" ] && PRIVATE_IP=$(wget -t 3 -T 5 -qO- 'http://169.254.169.254/latest/meta-data/local-ipv4')
-
-# Try to find IPs for non-EC2 servers
+# Try to auto discover IPs of this server
 [ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(dig @resolver1.opendns.com -t A -4 myip.opendns.com +short)
-[ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://whatismyip.akamai.com)
-[ -z "$PUBLIC_IP" ] && PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://ipv4.icanhazip.com)
 [ -z "$PRIVATE_IP" ] && PRIVATE_IP=$(ip -4 route get 1 | awk '{print $NF;exit}')
-[ -z "$PRIVATE_IP" ] && PRIVATE_IP=$(ifconfig eth0 | grep -Eo 'inet (addr:)?([0-9]*\.){3}[0-9]*' | grep -Eo '([0-9]*\.){3}[0-9]*')
 
 # Check IPs for correct format
 IP_REGEX="^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"
+if ! printf %s "$PUBLIC_IP" | grep -Eq "$IP_REGEX"; then
+  PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://whatismyip.akamai.com)
+fi
+if ! printf %s "$PUBLIC_IP" | grep -Eq "$IP_REGEX"; then
+  PUBLIC_IP=$(wget -t 3 -T 15 -qO- http://ipv4.icanhazip.com)
+fi
 if ! printf %s "$PUBLIC_IP" | grep -Eq "$IP_REGEX"; then
   exiterr "Cannot find valid public IP. Edit the script and manually enter IPs."
 fi
+if ! printf %s "$PRIVATE_IP" | grep -Eq "$IP_REGEX"; then
+  PRIVATE_IP=$(ifconfig eth0 | grep -Eo 'inet (addr:)?([0-9]*\.){3}[0-9]*' | grep -Eo '([0-9]*\.){3}[0-9]*')
+fi
 if ! printf %s "$PRIVATE_IP" | grep -Eq "$IP_REGEX"; then
   exiterr "Cannot find valid private IP. Edit the script and manually enter IPs."
 fi