implement one lua state per connectionHEADmaster

This allows you load various modules into a server lua state and give
a performance boost when calling the privileged functions

1 files changed, 64 insertions, 0 deletions

diff --git a/server/handler.lua b/server/handler.lua
new file mode 100644
index 0000000..41a02fb
--- /dev/null
+++ b/server/handler.lua
@@ -0,0 +1,64 @@
+
+--print("DEBUG: got message:", msg)
+
+--ipcmsg = require("json")
+ipcmsg = require("cmsgpack")
+ipcmsg.encode = ipcmsg.pack
+ipcmsg.decode = ipcmsg.unpack
+
+ml =  require("ml")
+
+modules_path = "../modules/"
+
+mods = {}
+
+local function ret_error(errmsg)
+	io.stderr:write("ERROR: "..tostring(errmsg).."\n")
+	return ipcmsg.encode{ status = false, errmsg = errmsg}
+end
+
+local function ret_success(...)
+	return ipcmsg.encode{ status = true, errmsg = "success",
+		result = {...} }
+end
+
+reqhandler = {}
+function reqhandler.load(req)
+	-- make sure we dont have any path elements in modname so we cannot pass
+	-- modnames like '../myevilmod'
+	local file = modules_path..string.gsub(req.modname, ".*/", "")..".lua"
+	mods[req.modidx] = dofile(file)
+	if mods[req.modidx] == nil then
+		return ret_error(file)
+	end
+	return true
+end
+
+function reqhandler.call(req)
+	if req.modidx == nil or req.func == nil then
+		return ret_error("failed to call function "..tostring(req.func))
+	end
+	local m = mods[req.modidx]
+	-- check that the func we want exists
+	if type(m[req.func]) ~= "function" then
+		ret_error(func..": not a function in '".. mfile .."'")
+	end
+
+	-- TODO: check permissions here
+--	print("DEBUG: Calling mods["..req.modidx.."]."..req.func)
+
+	-- execute the func and pack the return values into a table
+	return m[req.func](unpack(req.args))
+end
+
+function handler(msg)
+	local req = ipcmsg.decode(msg)
+--	print("DEBUG: req="..ml.tstring(req))
+	if type(req.type) ~= "string" then
+		return ret_error("request type missing")
+	end
+	if type(reqhandler[req.type]) == "function" then
+		return ret_success(reqhandler[req.type](req))
+	end
+	return ret_error("no handler for request type "..req.type)
+end