diff options
Diffstat (limited to 'net/server_epoll.lua')
| -rw-r--r-- | net/server_epoll.lua | 663 |
1 files changed, 663 insertions, 0 deletions
diff --git a/net/server_epoll.lua b/net/server_epoll.lua new file mode 100644 index 00000000..035a6b34 --- /dev/null +++ b/net/server_epoll.lua @@ -0,0 +1,663 @@ +-- Prosody IM +-- Copyright (C) 2016 Kim Alvefur +-- +-- This project is MIT/X11 licensed. Please see the +-- COPYING file in the source package for more information. +-- + +-- server_epoll +-- Server backend based on https://luarocks.org/modules/zash/lua-epoll + +local t_sort = table.sort; +local t_insert = table.insert; +local t_remove = table.remove; +local t_concat = table.concat; +local setmetatable = setmetatable; +local tostring = tostring; +local pcall = pcall; +local log = require "util.logger".init("server_epoll"); +local epoll = require "epoll"; +local socket = require "socket"; +local luasec = require "ssl"; +local gettime = require "util.time".now; +local createtable = require "util.table".create; + +assert(socket.tcp6 and socket.tcp4, "Incompatible LuaSocket version"); + +local _ENV = nil; + +local cfg = { + read_timeout = 900; + write_timeout = 7; + tcp_backlog = 128; + accept_retry_interval = 10; + read_retry_delay = 1e-06; + connect_timeout = 20; + handshake_timeout = 60; + max_wait = 86400; +}; + +local fds = createtable(10, 0); -- FD -> conn + +-- Timer and scheduling -- + +local timers = {}; + +local function noop() end +local function closetimer(t) + t[1] = 0; + t[2] = noop; +end + +-- Set to true when timers have changed +local resort_timers = false; + +-- Add absolute timer +local function at(time, f) + local timer = { time, f, close = closetimer }; + t_insert(timers, timer); + resort_timers = true; + return timer; +end + +-- Add relative timer +local function addtimer(timeout, f) + return at(gettime() + timeout, f); +end + +-- Run callbacks of expired timers +-- Return time until next timeout +local function runtimers(next_delay) + -- Any timers at all? + if not timers[1] then + return next_delay; + end + + if resort_timers then + -- Sort earliest timers to the end + t_sort(timers, function (a, b) return a[1] > b[1]; end); + resort_timers = false; + end + + -- Iterate from the end and remove completed timers + for i = #timers, 1, -1 do + local timer = timers[i]; + local t, f = timer[1], timer[2]; + -- Get time for every iteration to increase accuracy + local now = gettime(); + if t > now then + -- This timer should not fire yet + local diff = t - now; + if diff < next_delay then + next_delay = diff; + end + break; + end + local new_timeout = f(now); + if new_timeout then + -- Schedule for 'delay' from the time actually scheduled, + -- not from now, in order to prevent timer drift. + timer[1] = t + new_timeout; + resort_timers = true; + else + t_remove(timers, i); + end + end + if resort_timers or next_delay < 1e-6 then + -- Timers may be added from within a timer callback. + -- Those would not be considered for next_delay, + -- and we might sleep for too long, so instead + -- we return a shorter timeout so we can + -- properly sort all new timers. + next_delay = 1e-6; + end + return next_delay; +end + +-- Socket handler interface + +local interface = {}; +local interface_mt = { __index = interface }; + +function interface_mt:__tostring() + if self.sockname and self.peername then + return ("FD %d (%s, %d, %s, %d)"):format(self:getfd(), self.peername, self.peerport, self.sockname, self.sockport); + elseif self.sockname or self.peername then + return ("FD %d (%s, %d)"):format(self:getfd(), self.sockname or self.peername, self.sockport or self.peerport); + end + return ("%s FD %d"):format(tostring(self.conn), self:getfd()); +end + +-- Replace the listener and tell the old one +function interface:setlistener(listeners) + self:on("detach"); + self.listeners = listeners; +end + +-- Call a listener callback +function interface:on(what, ...) + local listener = self.listeners["on"..what]; + if not listener then + -- log("debug", "Missing listener 'on%s'", what); -- uncomment for development and debugging + return; + end + local ok, err = pcall(listener, self, ...); + if not ok then + log("error", "Error calling on%s: %s", what, err); + end + return err; +end + +-- Return the file descriptor number +function interface:getfd() + if self.conn then + return self.conn:getfd(); + end + return -1; +end + +-- Get IP address +function interface:ip() + return self.peername or self.sockname; +end + +-- Get a port number, doesn't matter which +function interface:port() + return self.sockport or self.peerport; +end + +-- Get local port number +function interface:clientport() + return self.sockport; +end + +-- Get remote port +function interface:serverport() + if self.sockport then + return self.sockport; + elseif self.server then + self.server:port(); + end +end + +-- Return underlying socket +function interface:socket() + return self.conn; +end + +function interface:setoption(k, v) + -- LuaSec doesn't expose setoption :( + if self.conn.setoption then + self.conn:setoption(k, v); + end +end + +-- Timeout for detecting dead or idle sockets +function interface:setreadtimeout(t) + if t == false then + if self._readtimeout then + self._readtimeout:close(); + self._readtimeout = nil; + end + return + end + t = t or cfg.read_timeout; + if self._readtimeout then + self._readtimeout[1] = gettime() + t; + resort_timers = true; + else + self._readtimeout = addtimer(t, function () + if self:on("readtimeout") then + return cfg.read_timeout; + else + self:on("disconnect", "read timeout"); + self:destroy(); + end + end); + end +end + +-- Timeout for detecting dead sockets +function interface:setwritetimeout(t) + if t == false then + if self._writetimeout then + self._writetimeout:close(); + self._writetimeout = nil; + end + return + end + t = t or cfg.write_timeout; + if self._writetimeout then + self._writetimeout[1] = gettime() + t; + resort_timers = true; + else + self._writetimeout = addtimer(t, function () + self:on("disconnect", "write timeout"); + self:destroy(); + end); + end +end + +-- lua-epoll flag for currently requested poll state +function interface:flags() + if self._wantread then + if self._wantwrite then + return "rw"; + end + return "r"; + elseif self._wantwrite then + return "w"; + end +end + +-- Add or remove sockets or modify epoll flags +function interface:setflags(r, w) + if r ~= nil then self._wantread = r; end + if w ~= nil then self._wantwrite = w; end + local flags = self:flags(); + local currentflags = self._flags; + if flags == currentflags then + return true; + end + local fd = self:getfd(); + if fd < 0 then + self._wantread, self._wantwrite = nil, nil; + return nil, "invalid fd"; + end + local op = "mod"; + if not flags then + op = "del"; + elseif not currentflags then + op = "add"; + end + local ok, err = epoll.ctl(op, fd, flags); +-- log("debug", "epoll_ctl(%q, %d, %q) -> %s" .. (err and ", %q" or ""), +-- op, fd, flags or "", tostring(ok), err); + if not ok then return ok, err end + if op == "add" then + fds[fd] = self; + elseif op == "del" then + fds[fd] = nil; + end + self._flags = flags; + return true; +end + +-- Called when socket is readable +function interface:onreadable() + local data, err, partial = self.conn:receive(self._pattern); + if self.conn:dirty() then + self:setreadtimeout(false); + self:pausefor(cfg.read_retry_delay); + else + self:setreadtimeout(); + end + if data or partial then + self:on("incoming", data or partial, err); + end + if err == "wantread" then + self:setflags(true, nil); + elseif err == "wantwrite" then + self:setflags(nil, true); + elseif not data and err ~= "timeout" then + self:on("disconnect", err); + self:destroy() + return; + end +end + +-- Called when socket is writable +function interface:onwriteable() + local buffer = self.writebuffer; + local data = t_concat(buffer); + local ok, err, partial = self.conn:send(data); + if ok then + for i = #buffer, 1, -1 do + buffer[i] = nil; + end + self:setflags(nil, false); + self:setwritetimeout(false); + self:ondrain(); -- Be aware of writes in ondrain + return; + elseif partial then + buffer[1] = data:sub(partial+1); + for i = #buffer, 2, -1 do + buffer[i] = nil; + end + self:setwritetimeout(); + end + if err == "wantwrite" or err == "timeout" then + self:setflags(nil, true); + elseif err == "wantread" then + self:setflags(true, nil); + elseif err and err ~= "timeout" then + self:on("disconnect", err); + self:destroy(); + end +end + +-- The write buffer has been successfully emptied +function interface:ondrain() + if self._toclose then + return self:close(); + elseif self._starttls then + return self:starttls(); + else + return self:on("drain"); + end +end + +-- Add data to write buffer and set flag for wanting to write +function interface:write(data) + local buffer = self.writebuffer; + if buffer then + t_insert(buffer, data); + else + self.writebuffer = { data }; + end + self:setwritetimeout(); + self:setflags(nil, true); + return #data; +end +interface.send = interface.write; + +-- Close, possibly after writing is done +function interface:close() + if self._wantwrite then + self:setflags(false, true); -- Flush final buffer contents + self.write, self.send = noop, noop; -- No more writing + log("debug", "Close %s after writing", tostring(self)); + self._toclose = true; + else + log("debug", "Close %s now", tostring(self)); + self.write, self.send = noop, noop; + self.close = noop; + self:on("disconnect"); + self:destroy(); + end +end + +function interface:destroy() + self:setflags(false, false); + self:setwritetimeout(false); + self:setreadtimeout(false); + self.onreadable = noop; + self.onwriteable = noop; + self.destroy = noop; + self.close = noop; + self.on = noop; + self.conn:close(); + self.conn = nil; +end + +function interface:ssl() + return self._tls; +end + +function interface:starttls(ctx) + if ctx then self.tls = ctx; end + if self.writebuffer and self.writebuffer[1] then + log("debug", "Start TLS on %s after write", tostring(self)); + self._starttls = true; + self:setflags(nil, true); -- make sure wantwrite is set + else + log("debug", "Start TLS on %s now", tostring(self)); + self:setflags(false, false); + local conn, err = luasec.wrap(self.conn, ctx or self.tls); + if not conn then + self:on("disconnect", err); + self:destroy(); + return conn, err; + end + conn:settimeout(0); + self.conn = conn; + self._starttls = nil; + self.onwriteable = interface.tlshandskake; + self.onreadable = interface.tlshandskake; + self:setflags(true, true); + self:setwritetimeout(cfg.handshake_timeout); + end +end + +function interface:tlshandskake() + self:setwritetimeout(false); + self:setreadtimeout(false); + local ok, err = self.conn:dohandshake(); + if ok then + log("debug", "TLS handshake on %s complete", tostring(self)); + self.onwriteable = nil; + self.onreadable = nil; + self:setflags(true, true); + local old = self._tls; + self._tls = true; + self.starttls = false; + if old == false then + self:init(); + else + self:setflags(true, true); + self:on("status", "ssl-handshake-complete"); + end + elseif err == "wantread" then + log("debug", "TLS handshake on %s to wait until readable", tostring(self)); + self:setflags(true, false); + self:setreadtimeout(cfg.handshake_timeout); + elseif err == "wantwrite" then + log("debug", "TLS handshake on %s to wait until writable", tostring(self)); + self:setflags(false, true); + self:setwritetimeout(cfg.handshake_timeout); + else + log("debug", "TLS handshake error on %s: %s", tostring(self), err); + self:on("disconnect", err); + self:destroy(); + end +end + +local function wrapsocket(client, server, pattern, listeners, tls) -- luasocket object -> interface object + client:settimeout(0); + local conn = setmetatable({ + conn = client; + server = server; + created = gettime(); + listeners = listeners; + _pattern = pattern or server._pattern; + writebuffer = {}; + tls = tls; + }, interface_mt); + + if client.getpeername then + conn.peername, conn.peerport = client:getpeername(); + end + if client.getsockname then + conn.sockname, conn.sockport = client:getsockname(); + end + return conn; +end + +-- A server interface has new incoming connections waiting +-- This replaces the onreadable callback +function interface:onacceptable() + local conn, err = self.conn:accept(); + if not conn then + log("debug", "Error accepting new client: %s, server will be paused for %ds", err, cfg.accept_retry_interval); + self:pausefor(cfg.accept_retry_interval); + return; + end + local client = wrapsocket(conn, self, nil, self.listeners, self.tls); + log("debug", "New connection %s", tostring(client)); + client:init(); +end + +-- Initialization +function interface:init() + if self.tls and not self._tls then + self._tls = false; -- This means we should call onconnect when TLS is up + return self:starttls(); + else + self.onwriteable = interface.onconnect; + self:setwritetimeout(); + return self:setflags(false, true); + end +end + +function interface:pause() + return self:setflags(false); +end + +function interface:resume() + return self:setflags(true); +end + +-- Pause connection for some time +function interface:pausefor(t) + if self._pausefor then + self._pausefor:close(); + end + if t == false then return; end + self:setflags(false); + self._pausefor = addtimer(t, function () + self._pausefor = nil; + if self.conn:dirty() then + self:onreadable(); + end + self:setflags(true); + end); +end + +-- Connected! +function interface:onconnect() + self.onwriteable = nil; + self:on("connect"); + self:setflags(true); + return self:onwriteable(); +end + +local function addserver(addr, port, listeners, pattern, tls) + local conn, err = socket.bind(addr, port, cfg.tcp_backlog); + if not conn then return conn, err; end + conn:settimeout(0); + local server = setmetatable({ + conn = conn; + created = gettime(); + listeners = listeners; + _pattern = pattern; + onreadable = interface.onacceptable; + tls = tls; + sockname = addr; + sockport = port; + }, interface_mt); + server:setflags(true, false); + return server; +end + +-- COMPAT +local function wrapclient(conn, addr, port, listeners, pattern, tls) + local client = wrapsocket(conn, nil, pattern, listeners, tls); + if not client.peername then + client.peername, client.peerport = addr, port; + end + client:init(); + return client; +end + +local function addclient(addr, port, listeners, pattern, tls) + local conn, err = socket.tcp(); + if not conn then return conn, err; end + conn:settimeout(0); + conn:connect(addr, port); + local client = wrapsocket(conn, nil, pattern, listeners, tls) + client:init(); + return client, conn; +end + +local function link(from, to) + from.listeners = setmetatable({ + onincoming = function (_, data) + from:pause(); + to:write(data); + end, + }, {__index=from.listeners}); + to.listeners = setmetatable({ + ondrain = function () + from:resume(); + end, + }, {__index=to.listeners}); + from:setflags(true, nil); + to:setflags(nil, true); +end + +-- XXX What uses this? +-- net.adns +function interface:set_send(new_send) + self.send = new_send; +end + +local quitting = nil; + +-- Signal main loop about shutdown via above upvalue +local function setquitting() + quitting = "quitting"; +end + +-- Main loop +local function loop() + repeat + local t = runtimers(cfg.max_wait); + local fd, r, w = epoll.wait(t); + if fd then + local conn = fds[fd]; + if conn then + if r then + conn:onreadable(); + end + if w then + conn:onwriteable(); + end + else + log("debug", "Removing unknown fd %d", fd); + epoll.ctl("del", fd); + end + elseif r ~= "timeout" then + log("debug", "epoll_wait error: %s", tostring(r)); + end + until quitting; + return quitting; +end + +return { + get_backend = function () return "epoll"; end; + addserver = addserver; + addclient = addclient; + add_task = addtimer; + at = at; + loop = loop; + setquitting = setquitting; + wrapclient = wrapclient; + link = link; + + -- libevent emulation + event = { EV_READ = "r", EV_WRITE = "w", EV_READWRITE = "rw", EV_LEAVE = -1 }; + addevent = function (fd, mode, callback) + local function onevent(self) + local ret = self:callback(); + if ret == -1 then + epoll.ctl("del", fd); + elseif ret then + epoll.ctl("mod", fd, mode); + end + end + + local conn = { + callback = callback; + onreadable = onevent; + onwriteable = onevent; + close = function () + fds[fd] = nil; + return epoll.ctl("del", fd); + end; + }; + fds[fd] = conn; + local ok, err = epoll.ctl("add", fd, mode or "r"); + if not ok then return ok, err; end + return conn; + end; +}; |