lua_examples.rst

Lua examples

Important that accel-ppp was built with lua support cmake -DLUA=TRUE or if system has more modern lua version, need this sets, for example cmake -DLUA=5.3

Example accel-ppp configuration:

[ipoe]
  lua-file=/etc/accel-ppp.lua
  username=lua:username_func

Create /etc/accel-ppp.lua and edit. Example for D-link switches with Option 82:

#!lua
  function username_func(pkt)
    v,b1,b2,b3,b4=string.unpack(pkt:agent_remote_id():sub(-4),'bbbb')
    ip=b1..'.'..b2..'.'..b3..'.'..b4
    v,port=string.unpack(string.sub(pkt:agent_circuit_id(),'-1'),'b')
    local username=ip..'-'..port
--  print(username)
    return username
end

Object pkt has next functions:

hdr(name)

Will return value which contained in DHCP packet header. name may receive next params: xid, ciaddr, giaddr, chaddr.

ifname()

Will return interface name which received packet.

options()

Will return table which contains number of DHCP option in received packet.

option(num)

Will return value with option number num.

agent_circuit_id()

Will return agent_circuit_id option 82.

agent_remote_id()

Will return agent_remote_id option 82.

Note:

All function return type string, except for options()

Also to accel-ppp includes packet lpack for disassemble binary data. It add to object string aditional function unpack(binary, fmt), where binary is string which contain binary data, and fmt``is data format. To ``fmt may be sets next data types:

z - zero terminated string

p - string precended by length byte

P - string precended by length word

f - float

d - double

c - int8_t

b - uint8_t

h - int16_t

H - uint16_t

i - int32_t

I - uint32_t

l - int64_t

L - uint64_t

< - little endian

> - big endian

= - native endian