Lua API

Initial author:
    Daniel-Constantin Mierla

Module app_lua allows execution of Lua scripts from SIP router configuration file, providing access to SIP message which is processed at that time. Exported functions by app_lua are available in the Lua script as package sr.

References:

• app_lua module: README
• Lua: http://www.lua.org

Core functions.

Print message to L_DBG level using internal log API.

Prototype

sr.dbg("message")

Print message to L_ERR level using internal log API.

Prototype

sr.err("message")

Print message to 'level' using internal log API.

Prototype

sr.log("level", "message")

Parameter level can be"

• dbg
• info
• warn
• err
• crit

Run a function exported by a module

Prototype:

sr.modf("function", "param1", "param2", ...);

Can be up to 6 optional parameters.

Example:

sr.modf("sl_reply_error");

Note that module functions that have parameter fixups cannot be executed unless they have free fixup. This is to prevent memory leaks caused by fixup functions. If you have doubts about a module function, whether it is safe to execute or not from Lua, ask on devel mailing list: sr-dev [at] lists.sip-router.org.

Header management functions.

Append header to end of headers list.

Prototype

sr.hdr.append("text")

Insert header to first position.

Prototype

sr.hdr.insert("text")

Remove header.

Prototype

sr.hdr.remove("hdrname")

Append a header to SIP reply generated by proxy.

Prototype

sr.hdr.append_to_reply("text")

Pseudo-variable management functions.

Get the value of a pseudo-variable.

Prototype

sr.pv.get("pv")

Set the integer value to pseudo-variable.

Prototype

sr.pv.seti("pv", value)

Set the string value to pseudo-variable.

Prototype

sr.pv.sets("pv", "value")

Unset pseudo-variables (assign $null).

Prototype

sr.pv.unset("pv")

Check if the pseudo-variable value is $null or not.

Prototype

sr.pv.is_null("pv")

Functions of SL module.

Send SIP reply.

Prototype

sr.sl.send_reply(code, "reason")

Example:

lua_dostring("sr.sl.send_reply(200, [[ok from lua]])");