daemon and stuff

example.cfg

@@ -0,0 +1,10 @@
+local config = {}
+
+config.path = "/var/gopher" -- the root path of the dir to be served
+config.hostname = "shadowkat.net" -- the hostname of the server
+config.port = 70 -- the external port of the server
+config.bindport = 7000 -- the port to actually bind to
+config.dirinfo = true -- whether to output some extra info in automatic directory indexes
+config.timer = 0.1 -- main loop timer
+
+return config

gopherd.lua

@@ -0,0 +1,134 @@
+local socket = require "socket"
+local fs = require "lfs"
+
+local tArgs = {...}
+
+local pcount = 0
+local threads = {}
+
+-- initial configuration
+local config = {}
+config.path = "/var/gopher"
+config.hostname = "shadowkat.net"
+config.port = 70
+config.bindport = 7000
+config.dirinfo = true
+config.timer = 0.1
+
+-- load the config as a lua script
+if tArgs[1] then
+ local f = io.open(tArgs[1],"rb")
+ local fn = load(f:read("*a"))
+ f:close()
+ if fn then
+  for k,v in pairs(fn()) do
+   config[k] = v
+  end
+ end
+end
+
+local function cleanPath(p) -- canonicalizes the path in theory
+ local t,o = {},""
+ for s in p:gmatch("[^/]+") do
+  if s == ".." then
+   t[#t] = nil
+  else
+   t[#t+1] = s
+  end
+ end
+ for k,v in pairs(t) do
+  o=o.."/"..v
+ end
+ return o
+end
+
+local function logerr(msg)
+ -- todo: proper error logging logic
+ print("error: "..msg)
+end
+
+local function detectft(path) -- tries to detect the file type
+ local attr = fs.attributes(path)
+ if attr.mode:sub(1,3) == "dir" then
+  return "1"
+ end
+ if path:sub(-4) == ".png" or path:sub(-4) == ".jpg" or path:sub(-5) == ".jpeg" or path:sub(-4) == ".bmp" or path:sub(-4) == "gif" then
+  return "I"
+ end
+ if path:sub(-5) == ".html" or path:sub(-4) == ".htm" then
+  return "h"
+ end
+ return "0"
+end
+
+local function handleConnect(client)
+ client:settimeout(0)
+ threads[pcount+1] = coroutine.create(function() local w,err = pcall(function()
+  repeat
+   coroutine.yield()
+   line=client:receive()
+  until line
+  print(line)
+  local path,args = config.path .. cleanPath(line)
+  local attr = fs.attributes(path)
+  if attr then
+   if attr.mode:sub(1,3) == "dir" then
+    if lfs.attributes(path.."/.gopherdir.cgi") then
+     local f = io.popen(path.."/.gopherdir.cgi")
+     coroutine.yield()
+     client:send(f:read("*a"))
+     f:close()
+    elseif lfs.attributes(path.."/.gopherdir") then
+     local f = io.open(path.."/.gopherdir")
+     client:send(f:read("*a"))
+     f:close()
+    else
+     if config.dirinfo then
+      client:send(string.format("i%s\ni%s\n",config.hostname,cleanPath(line)))
+     end
+     for file in lfs.dir(path) do
+      if file:sub(1,1) ~= "." then
+       client:send(string.format("%s%s\t%s\t%s\t%d\n",detectft(path.."/"..file),file,string.format("%s/%s",cleanPath(line),file),config.hostname,config.port))
+      end
+     end
+    end
+   else
+    if path:sub(-4) == ".cgi" then
+     local f = io.popen(path)
+     coroutine.yield()
+     client:send(f:read("*a"))
+     f:close()
+    else
+     local f = io.open(path)
+     client:send(f:read("*a"))
+     f:close()
+    end
+   end
+  else
+   client:send("Not found.")
+  end
+  client:close()
+ end)
+ if not w then
+  logerr(err)
+  client:close()
+ end
+ end)
+ pcount=pcount+1
+end
+
+local server = socket.bind("*",config.bindport)
+server:settimeout(config.timer)
+while true do -- totally not a scheduler
+ client = server:accept()
+ if client then
+  handleConnect(client)
+ end
+ for k,v in pairs(threads) do
+  if coroutine.status(v) == "dead" then
+   threads[k] = nil
+  else
+   coroutine.resume(v)
+  end
+ end
+end