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.

ipaddr()

Will return client ip address exist in packet header.

hwaddr()

Will return client MAC address.

vlan()

Will return client VLAN.

local vlan = pkt:vlan()
local svid = bit.rshift(vlan,16)
local cvid = bit.band(vlan,0xffff)

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 additional 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