Re: Retrieve public IP

[Sean Conner <sean@...>]

It was thus said that the Great Claudio Mussoni once stated:
> Hello to everyone,I need to get the public address from my router with LUA. 
> This is a PHP example:  $my_public_ip = $_SERVER['REMOTE_ADDR'];
> I searched around but I' ve not found examples.Someone can help me out?Thank's a lot.ByeClaudio

Here's how I do it:

#!/usr/bin/env lua

-- http://luasnmp.luaforge.net/snmp.html

snmp = require "snmp"
OID  = snmp.mib.oid

print("  Dest           Mask           If")
print("----------------------------------------")

router = assert(snmp.open{
                peer      = arg[1] or "192.168.1.1",
                community = arg[2] or "public"
                })

interfaces = {}

do
  local max = router['ifNumber.0']
  for i = 1 , max do
    interfaces[i] = router['ifDescr.' .. tostring(i)]
  end
end

setmetatable(interfaces,{ __index = function(t,k) return "(unknown)" end })
values = 
{
  addr = OID "IP-MIB::ipAdEntAddr",
  mask = OID "IP-MIB::ipAdEntNetMask",
  intf = OID "IP-MIB::ipAdEntIfIndex"
}

result = {}

for field,oid in pairs(values) do
  local tmp    = router[oid]
  local i      = 1;
  result[field] = {}

  for k,v in snmp.spairs(tmp) do
    result[field][i] = v
    i = i + 1
  end
  result.items = i - 1
end

for i=1,result.items do
  print(string.format("%-16s",result.addr[i])
        .. string.format("%-16s",result.mask[i])
        .. interfaces[result.intf[i]]
  )
end

And output:

  Dest           Mask           If
----------------------------------------
127.0.0.1       255.0.0.0       lo
192.168.1.1     255.255.255.0   br0
74.---.---.---  255.255.255.255 ipsec0

  -spc (But this supposes your router supports SNMP and it's configured)