src/ffluci/dispatcher.lua

   1 --[[
   2 FFLuCI - Dispatcher
   3
   4 Description:
   5 The request dispatcher and module dispatcher generators
   6
   7
   8 The dispatching process:
   9     For a detailed explanation of the dispatching process we assume:
  10     You have installed the FFLuCI CGI-Dispatcher in /cgi-bin/ffluci
  11
  12         To enforce a higher level of security only the CGI-Dispatcher
  13         resides inside the web server's document root, everything else
  14         stays inside an external directory, we assume this is /lua/ffluci
  15         for this explanation.
  16
  17     All controllers and action are reachable as sub-objects of /cgi-bin/ffluci
  18     as if they were virtual folders and files
  19         e.g.: /cgi-bin/ffluci/public/info/about
  20               /cgi-bin/ffluci/admin/network/interfaces
  21         and so on.
  22
  23     The PATH_INFO variable holds the dispatch path and
  24         will be split into three parts: /category/module/action
  25
  26     Category:   This is the category in which modules are stored in
  27                                 By default there are two categories:
  28                                 "public" - which is the default public category
  29                                 "admin"  - which is the default protected category
  30
  31                                 As FFLuCI itself does not implement authentication
  32                                 you should make sure that "admin" and other sensitive
  33                                 categories are protected by the webserver.
  34
  35                                 E.g. for busybox add a line like:
  36                                 /cgi-bin/ffluci/admin:root:$p$root
  37                                 to /etc/httpd.conf to protect the "admin" category
  38
  39
  40         Module:         This is the controller which will handle the request further
  41                                 It is always a submodule of ffluci.controller, so a module
  42                                 called "helloworld" will be stored in
  43                                 /lua/ffluci/controller/helloworld.lua
  44                                 You are free to submodule your controllers any further.
  45
  46         Action:         This is action that will be invoked after loading the module.
  47                     The kind of how the action will be dispatched depends on
  48                                 the module dispatcher that is defined in the controller.
  49                                 See the description of the default module dispatcher down
  50                                 on this page for some examples.
  51
  52
  53     The main dispatcher at first searches for the module by trying to
  54         include ffluci.controller.category.module
  55         (where "category" is the category name and "module" is the module name)
  56         If this fails a 404 status code will be send to the client and FFLuCI exits
  57
  58         Then the main dispatcher calls the module dispatcher
  59         ffluci.controller.category.module.dispatcher with the request object
  60         as the only argument. The module dispatcher is then responsible
  61         for the further dispatching process.
  62
  63
  64 FileId:
  65 $Id$
  66
  67 License:
  68 Copyright 2008 Steven Barth <steven@midlink.org>
  69
  70 Licensed under the Apache License, Version 2.0 (the "License");
  71 you may not use this file except in compliance with the License.
  72 You may obtain a copy of the License at
  73
  74         http://www.apache.org/licenses/LICENSE-2.0
  75
  76 Unless required by applicable law or agreed to in writing, software
  77 distributed under the License is distributed on an "AS IS" BASIS,
  78 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  79 See the License for the specific language governing permissions and
  80 limitations under the License.
  81
  82 ]]--
  83
  84 module("ffluci.dispatcher", package.seeall)
  85 require("ffluci.http")
  86 require("ffluci.template")
  87
  88
  89 -- Dispatches the "request"
  90 function dispatch(req)
  91         request = req
  92         local m = "ffluci.controller." .. request.category .. "." .. request.module
  93         local stat, module = pcall(require, m)
  94         if not stat then
  95                 return error404()
  96         else
  97                 module.request = request
  98                 module.dispatcher = module.dispatcher or dynamic
  99                 setfenv(module.dispatcher, module)
 100                 return module.dispatcher(request)
 101         end
 102 end
 103
 104 -- Sends a 404 error code and renders the "error404" template if available
 105 function error404(message)
 106         message = message or "Not Found"
 107
 108         if not pcall(ffluci.template.render, "error404") then
 109                 ffluci.http.textheader()
 110                 print(message)
 111         end
 112         return false
 113 end
 114
 115 -- Sends a 500 error code and renders the "error500" template if available
 116 function error500(message)
 117         ffluci.http.status(500, "Internal Server Error")
 118
 119         if not pcall(ffluci.template.render, "error500", {message=message}) then
 120                 ffluci.http.textheader()
 121                 print(message)
 122         end
 123         return false
 124 end
 125
 126
 127 -- Dispatches a request depending on the PATH_INFO variable
 128 function httpdispatch()
 129         local pathinfo = os.getenv("PATH_INFO") or ""
 130         local parts = pathinfo:gmatch("/[%w-]+")
 131
 132         local sanitize = function(s, default)
 133                 return s and s:sub(2) or default
 134         end
 135
 136         local cat = sanitize(parts(), "public")
 137         local mod = sanitize(parts(), "index")
 138         local act = sanitize(parts(), "index")
 139
 140         dispatch({category=cat, module=mod, action=act})
 141 end
 142
 143
 144 -- Dispatchers --
 145
 146
 147 -- The Action Dispatcher searches the module for any function called
 148 -- action_"request.action" and calls it
 149 function action(request)
 150         local i18n = require("ffluci.i18n")
 151         local disp = require("ffluci.dispatcher")
 152
 153         i18n.loadc(request.module)
 154         local action = getfenv()["action_" .. request.action:gsub("-", "_")]
 155         if action then
 156                 action()
 157         else
 158                 disp.error404()
 159         end
 160 end
 161
 162 -- The CBI dispatcher directly parses and renders the CBI map which is
 163 -- placed in ffluci/modles/cbi/"request.module"/"request.action"
 164 function cbi(request)
 165         local i18n = require("ffluci.i18n")
 166         local disp = require("ffluci.dispatcher")
 167         local tmpl = require("ffluci.template")
 168         local cbi  = require("ffluci.cbi")
 169
 170         local path = request.category.."_"..request.module.."/"..request.action
 171
 172         i18n.loadc(request.module)
 173
 174         local stat, map = pcall(cbi.load, path)
 175         if stat then
 176                 local stat, err = pcall(map.parse, map)
 177                 if not stat then
 178                         disp.error500(err)
 179                         return
 180                 end
 181                 tmpl.render("cbi/header")
 182                 map:render()
 183                 tmpl.render("cbi/footer")
 184         else
 185                 disp.error404()
 186         end
 187 end
 188
 189 -- The dynamic dispatchers combines the action, simpleview and cbi dispatchers
 190 -- in one dispatcher. It tries to lookup the request in this order.
 191 function dynamic(request)
 192         local i18n = require("ffluci.i18n")
 193         local disp = require("ffluci.dispatcher")
 194         local tmpl = require("ffluci.template")
 195         local cbi  = require("ffluci.cbi")
 196
 197         i18n.loadc(request.module)
 198
 199         local action = getfenv()["action_" .. request.action:gsub("-", "_")]
 200         if action then
 201                 action()
 202                 return
 203         end
 204
 205         local path = request.category.."_"..request.module.."/"..request.action
 206         if pcall(tmpl.render, path) then
 207                 return
 208         end
 209
 210         local stat, map = pcall(cbi.load, path)
 211         if stat then
 212                 local stat, err = pcall(map.parse, map)
 213                 if not stat then
 214                         disp.error500(err)
 215                         return
 216                 end
 217                 tmpl.render("cbi/header")
 218                 map:render()
 219                 tmpl.render("cbi/footer")
 220                 return
 221         end
 222
 223         disp.error404()
 224 end
 225
 226 -- The Simple View Dispatcher directly renders the template
 227 -- which is placed in ffluci/views/"request.module"/"request.action"
 228 function simpleview(request)
 229         local i18n = require("ffluci.i18n")
 230         local tmpl = require("ffluci.template")
 231         local disp = require("ffluci.dispatcher")
 232
 233         local path = request.category.."_"..request.module.."/"..request.action
 234
 235         i18n.loadc(request.module)
 236         if not pcall(tmpl.render, path) then
 237                 disp.error404()
 238         end
 239 end