prosody
a08065207ef0
net/http/errors.lua
Software / code / prosody
File
net/http/errors.lua @ 13652:a08065207ef0
net.server_epoll: Call :shutdown() on TLS sockets when supported
Comment from Matthew:
This fixes a potential issue where the Prosody process gets blocked on sockets
waiting for them to close. Unlike non-TLS sockets, closing a TLS socket sends
layer 7 data, and this can cause problems for sockets which are in the process
of being cleaned up.
This depends on LuaSec changes which are not yet upstream.
From Martijn's original email:
So first my analysis of luasec. in ssl.c the socket is put into blocking
mode right before calling SSL_shutdown() inside meth_destroy(). My best
guess to why this is is because meth_destroy is linked to the __close
and __gc methods, which can't exactly be called multiple times and
luasec does want to make sure that a tls session is shutdown as clean
as possible.
I can't say I disagree with this reasoning and don't want to change this
behaviour. My solution to this without changing the current behaviour is
to introduce a shutdown() method. I am aware that this overlaps in a
conflicting way with tcp's shutdown method, but it stays close to the
OpenSSL name. This method calls SSL_shutdown() in the current
(non)blocking mode of the underlying socket and returns a boolean
whether or not the shutdown is completed (matching SSL_shutdown()'s 0
or 1 return values), and returns the familiar ssl_ioerror() strings on
error with a false for completion. This error can then be used to
determine if we have wantread/wantwrite to finalize things. Once
meth_shutdown() has been called once a shutdown flag will be set, which
indicates to meth_destroy() that the SSL_shutdown() has been handled
by the application and it shouldn't be needed to set the socket to
blocking mode. I've left the SSL_shutdown() call in the
LSEC_STATE_CONNECTED to prevent TOCTOU if the application reaches a
timeout for the shutdown code, which might allow SSL_shutdown() to
clean up anyway at the last possible moment.
Another thing I've changed to luasec is the call to socket_setblocking()
right before calling close(2) in socket_destroy() in usocket.c.
According to the latest POSIX[0]:
Note that the requirement for close() on a socket to block for up to
the current linger interval is not conditional on the O_NONBLOCK
setting.
Which I read to mean that removing O_NONBLOCK on the socket before close
doesn't impact the behaviour and only causes noise in system call
tracers. I didn't touch the windows bits of this, since I don't do
windows.
For the prosody side of things I've made the TLS shutdown bits resemble
interface:onwritable(), and put it under a combined guard of self._tls
and self.conn.shutdown. The self._tls bit is there to prevent getting
stuck on this condition, and self.conn.shutdown is there to prevent the
code being called by instances where the patched luasec isn't deployed.
The destroy() method can be called from various places and is read by
me as the "we give up" error path. To accommodate for these unexpected
entrypoints I've added a single call to self.conn:shutdown() to prevent
the socket being put into blocking mode. I have no expectations that
there is any other use here. Same as previous, the self.conn.shutdown
check is there to make sure it's not called on unpatched luasec
deployments and self._tls is there to make sure we don't call shutdown()
on tcp sockets.
I wouldn't recommend logging of the conn:shutdown() error inside
close(), since a lot of clients simply close the connection before
SSL_shutdown() is done.
| author | Martijn van Duren <martijn@openbsd.org> |
|---|---|
| date | Thu, 06 Feb 2025 15:04:38 +0000 |
| parent | 12974:ba409c67353b |
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-- This module returns a table that is suitable for use as a util.error registry, -- and a function to return a util.error object given callback 'code' and 'body' -- parameters. local codes = require "prosody.net.http.codes"; local util_error = require "prosody.util.error"; local error_templates = { -- This code is used by us to report a client-side or connection error. -- Instead of using the code, use the supplied body text to get one of -- the more detailed errors below. [0] = { code = 0, type = "cancel", condition = "internal-server-error"; text = "Connection or internal error"; }; -- These are net.http built-in errors, they are returned in -- the body parameter when code == 0 ["cancelled"] = { code = 0, type = "cancel", condition = "remote-server-timeout"; text = "Request cancelled"; }; ["connection-closed"] = { code = 0, type = "wait", condition = "remote-server-timeout"; text = "Connection closed"; }; ["certificate-chain-invalid"] = { code = 0, type = "cancel", condition = "remote-server-timeout"; text = "Server certificate not trusted"; }; ["certificate-verify-failed"] = { code = 0, type = "cancel", condition = "remote-server-timeout"; text = "Server certificate invalid"; }; ["connection failed"] = { code = 0, type = "cancel", condition = "remote-server-not-found"; text = "Connection failed"; }; ["invalid-url"] = { code = 0, type = "modify", condition = "bad-request"; text = "Invalid URL"; }; ["unable to resolve service"] = { code = 0, type = "cancel", condition = "remote-server-not-found"; text = "DNS resolution failed"; }; -- This doesn't attempt to map every single HTTP code (not all have sane mappings), -- but all the common ones should be covered. XEP-0086 was used as reference for -- most of these. [400] = { type = "modify", condition = "bad-request" }; [401] = { type = "auth", condition = "not-authorized" }; [402] = { type = "auth", condition = "payment-required" }; [403] = { type = "auth", condition = "forbidden" }; [404] = { type = "cancel", condition = "item-not-found" }; [405] = { type = "cancel", condition = "not-allowed" }; [406] = { type = "modify", condition = "not-acceptable" }; [407] = { type = "auth", condition = "registration-required" }; [408] = { type = "wait", condition = "remote-server-timeout" }; [409] = { type = "cancel", condition = "conflict" }; [410] = { type = "cancel", condition = "gone" }; [411] = { type = "modify", condition = "bad-request" }; [412] = { type = "cancel", condition = "conflict" }; [413] = { type = "modify", condition = "resource-constraint" }; [414] = { type = "modify", condition = "resource-constraint" }; [415] = { type = "cancel", condition = "feature-not-implemented" }; [416] = { type = "modify", condition = "bad-request" }; [422] = { type = "modify", condition = "bad-request" }; [423] = { type = "wait", condition = "resource-constraint" }; [429] = { type = "wait", condition = "resource-constraint" }; [431] = { type = "modify", condition = "resource-constraint" }; [451] = { type = "auth", condition = "forbidden" }; [500] = { type = "wait", condition = "internal-server-error" }; [501] = { type = "cancel", condition = "feature-not-implemented" }; [502] = { type = "wait", condition = "remote-server-timeout" }; [503] = { type = "cancel", condition = "service-unavailable" }; [504] = { type = "wait", condition = "remote-server-timeout" }; [507] = { type = "wait", condition = "resource-constraint" }; [511] = { type = "auth", condition = "not-authorized" }; }; for k, v in pairs(codes) do if error_templates[k] then error_templates[k].code = k; error_templates[k].text = v; else error_templates[k] = { type = "cancel", condition = "undefined-condition", text = v, code = k }; end end setmetatable(error_templates, { __index = function(_, k) if type(k) ~= "number" then return nil; end return { type = "cancel"; condition = "undefined-condition"; text = codes[k] or (k.." Unassigned"); code = k; }; end }); local function new(code, body, context) if code == 0 then return util_error.new(body, context, error_templates); else return util_error.new(code, context, error_templates); end end return { registry = error_templates; new = new; };
