--- a/net/websocket/frames.lua Mon Jan 04 11:44:40 2016 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,195 +0,0 @@
--- Prosody IM
--- Copyright (C) 2012 Florian Zeitz
--- Copyright (C) 2014 Daurnimator
---
--- This project is MIT/X11 licensed. Please see the
--- COPYING file in the source package for more information.
---
-
-local softreq = require "util.dependencies".softreq;
-local log = require "util.logger".init "websocket.frames";
-local random_bytes = require "util.random".bytes;
-
-local bit;
-pcall(function() bit = require"bit"; end);
-bit = bit or softreq"bit32"
-if not bit then log("error", "No bit module found. Either LuaJIT 2, lua-bitop or Lua 5.2 is required"); end
-local band = bit.band;
-local bor = bit.bor;
-local bxor = bit.bxor;
-local lshift = bit.lshift;
-local rshift = bit.rshift;
-
-local t_concat = table.concat;
-local s_byte = string.byte;
-local s_char= string.char;
-local s_sub = string.sub;
-
-local function read_uint16be(str, pos)
- local l1, l2 = s_byte(str, pos, pos+1);
- return l1*256 + l2;
-end
--- FIXME: this may lose precision
-local function read_uint64be(str, pos)
- local l1, l2, l3, l4, l5, l6, l7, l8 = s_byte(str, pos, pos+7);
- return lshift(l1, 56) + lshift(l2, 48) + lshift(l3, 40) + lshift(l4, 32)
- + lshift(l5, 24) + lshift(l6, 16) + lshift(l7, 8) + l8;
-end
-local function pack_uint16be(x)
- return s_char(rshift(x, 8), band(x, 0xFF));
-end
-local function get_byte(x, n)
- return band(rshift(x, n), 0xFF);
-end
-local function pack_uint64be(x)
- return s_char(rshift(x, 56), get_byte(x, 48), get_byte(x, 40), get_byte(x, 32),
- get_byte(x, 24), get_byte(x, 16), get_byte(x, 8), band(x, 0xFF));
-end
-
-local function parse_frame_header(frame)
- if #frame < 2 then return; end
-
- local byte1, byte2 = s_byte(frame, 1, 2);
- local result = {
- FIN = band(byte1, 0x80) > 0;
- RSV1 = band(byte1, 0x40) > 0;
- RSV2 = band(byte1, 0x20) > 0;
- RSV3 = band(byte1, 0x10) > 0;
- opcode = band(byte1, 0x0F);
-
- MASK = band(byte2, 0x80) > 0;
- length = band(byte2, 0x7F);
- };
-
- local length_bytes = 0;
- if result.length == 126 then
- length_bytes = 2;
- elseif result.length == 127 then
- length_bytes = 8;
- end
-
- local header_length = 2 + length_bytes + (result.MASK and 4 or 0);
- if #frame < header_length then return; end
-
- if length_bytes == 2 then
- result.length = read_uint16be(frame, 3);
- elseif length_bytes == 8 then
- result.length = read_uint64be(frame, 3);
- end
-
- if result.MASK then
- result.key = { s_byte(frame, length_bytes+3, length_bytes+6) };
- end
-
- return result, header_length;
-end
-
--- XORs the string `str` with the array of bytes `key`
--- TODO: optimize
-local function apply_mask(str, key, from, to)
- from = from or 1
- if from < 0 then from = #str + from + 1 end -- negative indicies
- to = to or #str
- if to < 0 then to = #str + to + 1 end -- negative indicies
- local key_len = #key
- local counter = 0;
- local data = {};
- for i = from, to do
- local key_index = counter%key_len + 1;
- counter = counter + 1;
- data[counter] = s_char(bxor(key[key_index], s_byte(str, i)));
- end
- return t_concat(data);
-end
-
-local function parse_frame_body(frame, header, pos)
- if header.MASK then
- return apply_mask(frame, header.key, pos, pos + header.length - 1);
- else
- return frame:sub(pos, pos + header.length - 1);
- end
-end
-
-local function parse_frame(frame)
- local result, pos = parse_frame_header(frame);
- if result == nil or #frame < (pos + result.length) then return; end
- result.data = parse_frame_body(frame, result, pos+1);
- return result, pos + result.length;
-end
-
-local function build_frame(desc)
- local data = desc.data or "";
-
- assert(desc.opcode and desc.opcode >= 0 and desc.opcode <= 0xF, "Invalid WebSocket opcode");
- if desc.opcode >= 0x8 then
- -- RFC 6455 5.5
- assert(#data <= 125, "WebSocket control frames MUST have a payload length of 125 bytes or less.");
- end
-
- local b1 = bor(desc.opcode,
- desc.FIN and 0x80 or 0,
- desc.RSV1 and 0x40 or 0,
- desc.RSV2 and 0x20 or 0,
- desc.RSV3 and 0x10 or 0);
-
- local b2 = #data;
- local length_extra;
- if b2 <= 125 then -- 7-bit length
- length_extra = "";
- elseif b2 <= 0xFFFF then -- 2-byte length
- b2 = 126;
- length_extra = pack_uint16be(#data);
- else -- 8-byte length
- b2 = 127;
- length_extra = pack_uint64be(#data);
- end
-
- local key = ""
- if desc.MASK then
- local key_a = desc.key
- if key_a then
- key = s_char(unpack(key_a, 1, 4));
- else
- key = random_bytes(4);
- key_a = {key:byte(1,4)};
- end
- b2 = bor(b2, 0x80);
- data = apply_mask(data, key_a);
- end
-
- return s_char(b1, b2) .. length_extra .. key .. data
-end
-
-local function parse_close(data)
- local code, message
- if #data >= 2 then
- code = read_uint16be(data, 1);
- if #data > 2 then
- message = s_sub(data, 3);
- end
- end
- return code, message
-end
-
-local function build_close(code, message, mask)
- local data = pack_uint16be(code);
- if message then
- assert(#message<=123, "Close reason must be <=123 bytes");
- data = data .. message;
- end
- return build_frame({
- opcode = 0x8;
- FIN = true;
- MASK = mask;
- data = data;
- });
-end
-
-return {
- parse_header = parse_frame_header;
- parse_body = parse_frame_body;
- parse = parse_frame;
- build = build_frame;
- parse_close = parse_close;
- build_close = build_close;
-};