Software /
code /
prosody
File
net/websocket/frames.lua @ 13149:0aaf67f70015
mod_storage_sql: Add setting to tune SQLite3 performance vs safety
Notably the default journal_mode of DELETE is somewhat slow, some users
might want to catch up to the amazing performance of internal storage.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Sun, 11 Jun 2023 17:04:11 +0200 |
parent | 12974:ba409c67353b |
child | 13250:cfd062d025b0 |
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-- 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` -- TODO: optimize 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; };