Name

lua-resty-wirefilter - LuaJIT FFI bindings to wirefilter, An execution engine for Wireshark-like filters

Table of Contents

• Name
• Status
• Synopsis
• Methods
  • new
  • exec
• Installation
• Authors

Synopsis

local wirefilter = require "resty.wirefilter"

local wf, err = wirefilter:new({
    fields = {
        ["http.user_agent"] = wirefilter.types.BYTES,
        ["http.port"] = wirefilter.types.INT,
        ["http.remote_ip"] = wirefilter.types.IP,
        ["ssl"] = wirefilter.types.BOOL
    },
    filter = "http.user_agent matches \"(googlebot|facebook)\" && http.port == 80 && http.remote_ip == 192.168.0.1 && ssl"
})


local match_result, err = wf:exec({
    ["http.user_agent"] = "googlebot",
    ["http.port"] = 80,
    ["ssl"] = true,
    ["http.remote_ip"] = "192.168.0.1"
})

Methods

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new

syntax: wf, err = wirefilter:new(args)

Creates a wirefilter instance.

args is a table containing the following settings:

• fields a table containing the necessary fields.
• filter wirefilter-style filter

fields contains the names of the fields and their type. We have 4 types in wirefilter:

• Bytes: wirefilter.types.BYTES
• Integer: wirefilter.types.INT
• IP Address: wirefilter.types.IP
• Boolean: wirefilter.types.BOOL

fields example:

fields = {
    ["http.user_agent"] = wirefilter.types.BYTES,
    ["http.port"] = wirefilter.types.INT,
    ["http.remote_ip"] = wirefilter.types.IP,
    ["ssl"] = wirefilter.types.BOOL
}

exec

syntax: result, err = wirefilter:exec(values)

exec matches the given values against the filter. If will

values is a table containing the fields and their values.

values example:

{
    ["http.user_agent"] = "googlebot",
    ["http.port"] = 80,
    ["ssl"] = true,
    ["http.remote_ip"] = "192.168.0.1"
}

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Installation

To run this module, You need to compile the wirefilter lib and put the .so file where OpenResty can find it:

https://github.com/cloudflare/wirefilter/tree/master/ffi

Build

Run the following in the module directory:

luarocks make

You need to configure the lua_package_path directive to add the path of your lua-resty-wirefilter source tree to ngx_lua's Lua module search path, as in

http {
    lua_package_path "/path/to/lua-resty-wirefilter/lib/?.lua;;";
    ...
}

and then load the library in Lua:

local wf = require "resty.wirefilter"

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Authors

Amir Keshavarz amirkekh@gmail.com.

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