* libs/http: prepare support for RFC2616 / 14.24 - 14.28

1 files changed, 111 insertions, 0 deletions

diff --git a/libs/http/luasrc/http/protocol/conditionals.lua b/libs/http/luasrc/http/protocol/conditionals.lua
new file mode 100644
index 000000000..0bff274cd
--- /dev/null
+++ b/libs/http/luasrc/http/protocol/conditionals.lua
@@ -0,0 +1,111 @@
+--[[
+
+HTTP protocol implementation for LuCI - RFC2616 / 14.19, 14.24 - 14.28
+(c) 2008 Freifunk Leipzig / Jo-Philipp Wich <xm@leipzig.freifunk.net>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+$Id$
+
+]]--
+
+module("luci.http.protocol.conditionals", package.seeall)
+
+local date = require("luci.http.protocol.date")
+
+
+-- 14.19 / ETag
+function mk_etag( stat )
+	if stat ~= nil then
+		return string.format( "%x-%x-%x", stat.ino, stat.size, stat.mtime )
+	end
+end
+
+-- 14.24 / If-Match
+function if_match( req, stat )
+	local h    = req.headers
+	local etag = mk_etag( stat )
+
+	-- Check for matching resource
+	if type(h['If-Match']) == "string" then
+		for ent in h['If-Match']:gmatch("([^, ]+)") do
+			if ( ent == '*' or ent == etag ) and stat ~= nil then
+				return true
+			end
+		end
+
+		return false, 412
+	end
+
+	return true
+end
+
+-- 14.25 / If-Modified-Since
+function if_modified_since( req, stat )
+	local h = req.headers
+
+	-- Compare mtimes
+	if type(h['If-Modified-Since']) == "string" then
+		local since = date.to_unix( h['If-Modified-Since'] )
+
+		if stat == nil or since < stat.mtime then
+			return true
+		end
+
+		return false, 304
+	end
+
+	return true
+end
+
+-- 14.26 / If-None-Match
+function if_none_match( req, stat )
+	local h    = req.headers
+	local etag = mk_etag( stat )
+
+	-- Check for matching resource
+	if type(h['If-None-Match']) == "string" then
+		for ent in h['If-None-Match']:gmatch("([^, ]+)") do
+			if ( ent == '*' or ent == etag ) and stat ~= nil then
+				if req.request_method == "get"  or
+				   req.request_method == "head"
+				then
+					h['ETag']          = mk_etag( stat )
+					h['Last-Modified'] = date.to_http( stat.mtime )
+
+					return false, 304
+				else
+					return false, 412
+				end
+			end
+		end
+	end
+
+	return true
+end
+
+-- 14.27 / If-Range
+function if_range( req, stat )
+	-- Sorry, no subranges (yet)
+	return false, 412
+end
+
+-- 14.28 / If-Unmodified-Since
+function if_unmodified_since( req, stat )
+	local h = req.headers
+
+	-- Compare mtimes
+	if type(h['If-Unmodified-Since']) == "string" then
+		local since = date.to_unix( h['If-Unmodified-Since'] )
+
+		if stat ~= nil and since <= stat.mtime then
+			return false, 412
+		end
+	end
+
+	return true
+end