Help in how to route all traffic: WAN - LAN and OpenVPN - LAN

Installing and Using OpenWrt Network and Wireless Configuration
25

I assume it works from OpenWrt, just requires login and password to access.
And probably that Web-UI is limited to LAN-network, so clients in WAN+VPN-networks need additional SNAT-rules:

uci add firewall redirect
uci set firewall.@redirect[-1].name='SNAT-HTTP-WAN-LAN'
uci set firewall.@redirect[-1].src='wan'
uci set firewall.@redirect[-1].src_dip='172.16.0.254'
uci set firewall.@redirect[-1].dest='lan'
uci set firewall.@redirect[-1].dest_port="80"
uci set firewall.@redirect[-1].proto="tcp"
uci set firewall.@redirect[-1].target='SNAT'
uci add firewall redirect
uci set firewall.@redirect[-1].name='SNAT-HTTP-VPN-LAN'
uci set firewall.@redirect[-1].src='VPN_client'
uci set firewall.@redirect[-1].src_dip='172.16.0.254'
uci set firewall.@redirect[-1].dest='lan'
uci set firewall.@redirect[-1].dest_port="80"
uci set firewall.@redirect[-1].proto="tcp"
uci set firewall.@redirect[-1].target='SNAT'
uci commit firewall
service firewall restart

OpenWrt-diagnostics should show similar result while opening HTTP from LAN-client:

# tcpdump -ni any tcp and port http
192.168.198.X:XXXXX	>	192.168.198.13:80	- DNAT begin
172.16.0.254:XXXXX	>	172.16.0.1:80		- SNAT begin
172.16.0.1:80		>	172.16.0.254:XXXXX	- SNAT end
192.168.198.13:80	>	192.168.198.X:XXXXX	- DNAT end
...
26

You're right, this is the result after the latest rules:

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on any, link-type LINUX_SLL (Linux cooked), capture size 262144 bytes
07:04:48.882861 ethertype IPv4, IP 192.168.198.102.57612 > 192.168.198.13.80: Flags [SEW], seq 2387229591, win 65535, options [mss 1460,nop,wscale 6,nop,nop,TS val 24511784 ecr 0,sackOK,eol], length 0
07:04:48.882861 IP 192.168.198.102.57612 > 192.168.198.13.80: Flags [SEW], seq 2387229591, win 65535, options [mss 1460,nop,wscale 6,nop,nop,TS val 24511784 ecr 0,sackOK,eol], length 0
07:04:48.883101 IP 172.16.0.254.57612 > 172.16.0.1.80: Flags [SEW], seq 2387229591, win 65535, options [mss 1460,nop,wscale 6,nop,nop,TS val 24511784 ecr 0,sackOK,eol], length 0
07:04:48.883125 IP 172.16.0.254.57612 > 172.16.0.1.80: Flags [SEW], seq 2387229591, win 65535, options [mss 1460,nop,wscale 6,nop,nop,TS val 24511784 ecr 0,sackOK,eol], length 0
07:04:48.888285 ethertype IPv4, IP 172.16.0.1.80 > 172.16.0.254.57612: Flags [S.], seq 4158880982, ack 2387229592, win 16384, options [mss 1460,nop,wscale 0,nop,nop,TS val 7803 ecr 24511784], length 0
07:04:48.888285 IP 172.16.0.1.80 > 172.16.0.254.57612: Flags [S.], seq 4158880982, ack 2387229592, win 16384, options [mss 1460,nop,wscale 0,nop,nop,TS val 7803 ecr 24511784], length 0
07:04:48.888285 IP 172.16.0.1.80 > 172.16.0.254.57612: Flags [S.], seq 4158880982, ack 2387229592, win 16384, options [mss 1460,nop,wscale 0,nop,nop,TS val 7803 ecr 24511784], length 0

Now it open this web page (you can save as html and open it):

<!--Web Server Error Report:<HR>
-->
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
  "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Login Incorrect</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css">
body,p{font-family:Arial;font-size:14px;line-height:180%%;text-align:left;}
h1{text-align:left;font-size:30px;line-height:normal;color:#0068B1}
#errorbody{width:620px;display:block;padding-top:5em}
</style>

</head>
<body>
<div align="center">
<div id="errorbody">
<h1>Username or Password is incorrect.<BR> Please refer to the troubleshooting below:</h1>
<br>
<p>
<b><font size="4">Is the "Caps Lock" enabled on your keyboard?</font></b>
<br>
The username and password must be lowercase, please ensure that the "Caps Lock" LED is disabled on your keyboard and try again.</p>
<p><b><font size="4">Forgot your username or password?</font></b><br>
Please reset the device to the factory default settings if you have forgotten your username or password. The default username and password are both set as <b>"admin"</b>.<br>
<b><font color=#ee0000>Note: The settings will be restored to factory default after the resetting.</font></b></p>
<p><b><font size="4">How to restore the device to the factory default settings?</font></b><br>
Firstly locate the reset button on the rear panel of the unit, whilst the device is powered on press and hold the <b>reset</b> button for more than 5 seconds, the device will then reboot and restore itself to the factory default settings.  </p>
</div>
</div>
</body>
</html>