mod_posix: Move everything to util.startup
This allows greater control over the order of events.
Notably, the internal ordering between daemonization, initialization of
libunbound and setup of signal handling is sensitive.
libunbound starts a separate thread for processing DNS requests.
If this thread is started before signal handling has been set up, it
will not inherit the signal handlers and instead behave as it would have
before signal handlers were set up, i.e. cause the whole process to
immediately exit.
libunbound is usually initialized on the first DNS request, usually
triggered by an outgoing s2s connection attempt.
If daemonization happens before signals have been set up, signals may
not be processed at all.
-- 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 random_bytes = require "prosody.util.random".bytes;
local bit = require "prosody.util.bitcompat";
local band = bit.band;
local bor = bit.bor;
local sbit = require "prosody.util.strbitop";
local sxor = sbit.sxor;
local s_char = string.char;
local s_pack = require"prosody.util.struct".pack;
local s_unpack = require"prosody.util.struct".unpack;
local function pack_uint16be(x)
return s_pack(">I2", x);
end
local function pack_uint64be(x)
return s_pack(">I8", x);
end
local function read_uint16be(str, pos)
if type(str) ~= "string" then
str, pos = str:sub(pos, pos+1), 1;
end
return s_unpack(">I2", str, pos);
end
local function read_uint64be(str, pos)
if type(str) ~= "string" then
str, pos = str:sub(pos, pos+7), 1;
end
return s_unpack(">I8", str, pos);
end
local function parse_frame_header(frame)
if frame:len() < 2 then return; end
local byte1, byte2 = frame:byte(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:len() < 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 = frame:sub(length_bytes+3, length_bytes+6);
end
return result, header_length;
end
-- XORs the string `str` with the array of bytes `key`
local function apply_mask(str, key, from, to)
return sxor(str:sub(from or 1, to or -1), key);
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:len() < (pos + result.length) then return nil, nil, result; 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
key = desc.key
if not key then
key = random_bytes(4);
end
b2 = bor(b2, 0x80);
data = apply_mask(data, key);
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 = data:sub(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;
};