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plugins/mod_scansion_record.lua @ 11665:148075532021
net.server_epoll: Prevent stack overflow of opportunistic writes
net.http.files serving a big enough file on a fast enough connection
with opportunistic_writes enabled could trigger a stack overflow through
repeatedly serving more data that immediately gets sent, draining the
buffer and triggering more data to be sent. This also blocked the server
on a single task until completion or an error.
This change prevents nested opportunistic writes, which should prevent
the stack overflow, at the cost of reduced download speed, but this is
unlikely to be noticeable outside of Gbit networks. Speed at the cost of
blocking other processing is not worth it, especially with the risk of
stack overflow.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Sun, 11 Jul 2021 09:39:21 +0200 |
parent | 11254:613035d6e5a0 |
child | 12110:b5b799a2a10c |
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local names = { "Romeo", "Juliet", "Mercutio", "Tybalt", "Benvolio" }; local devices = { "", "phone", "laptop", "tablet", "toaster", "fridge", "shoe" }; local users = {}; local filters = require "util.filters"; local id = require "util.id"; local dt = require "util.datetime"; local dm = require "util.datamanager"; local st = require "util.stanza"; local record_id = id.medium():lower(); local record_date = os.date("%Y%b%d"):lower(); local header_file = dm.getpath(record_id, "scansion", record_date, "scs", true); local record_file = dm.getpath(record_id, "scansion", record_date, "log", true); local head = io.open(header_file, "w"); local scan = io.open(record_file, "w+"); local function record(string) scan:write(string); scan:flush(); end local function record_header(string) head:write(string); head:flush(); end local function record_object(class, name, props) head:write(("[%s] %s\n"):format(class, name)); for k,v in pairs(props) do head:write(("\t%s: %s\n"):format(k, v)); end head:write("\n"); head:flush(); end local function record_event(session, event) record(session.scansion_id.." "..event.."\n\n"); end local function record_stanza(stanza, session, verb) local flattened = tostring(stanza:indent(2, "\t")); record(session.scansion_id.." "..verb..":\n\t"..flattened.."\n\n"); end local function record_stanza_in(stanza, session) if stanza.attr.xmlns == nil then local copy = st.clone(stanza); copy.attr.from = nil; record_stanza(copy, session, "sends") end return stanza; end local function record_stanza_out(stanza, session) if stanza.attr.xmlns == nil then if not (stanza.name == "iq" and stanza:get_child("bind", "urn:ietf:params:xml:ns:xmpp-bind")) then local copy = st.clone(stanza); if copy.attr.to == session.full_jid then copy.attr.to = nil; end record_stanza(copy, session, "receives"); end end return stanza; end module:hook("resource-bind", function (event) local session = event.session; if not users[session.username] then users[session.username] = { character = table.remove(names, 1) or id.short(); devices = {}; n_devices = 0; }; end local user = users[session.username]; local device = user.devices[session.resource]; if not device then user.n_devices = user.n_devices + 1; device = devices[user.n_devices] or ("device"..id.short()); user.devices[session.resource] = device; end session.scansion_character = user.character; session.scansion_device = device; session.scansion_id = user.character..(device ~= "" and "'s "..device or device); record_object("Client", session.scansion_id, { jid = session.full_jid, password = "password", }); module:log("info", "Connected: %s", session.scansion_id); record_event(session, "connects"); filters.add_filter(session, "stanzas/in", record_stanza_in); filters.add_filter(session, "stanzas/out", record_stanza_out); end); module:hook("resource-unbind", function (event) local session = event.session; if session.scansion_id then record_event(session, "disconnects"); end end) record_header("# mod_scansion_record on host '"..module.host.."' recording started "..dt.datetime().."\n\n"); record[[ ----- ]] module:hook_global("server-stopping", function () record("# recording ended on "..dt.datetime().."\n"); module:log("info", "Scansion recording available in %s", header_file); end); prosody.events.add_handler("server-cleanup", function () scan:seek("set", 0); for line in scan:lines() do head:write(line, "\n"); end scan:close(); os.remove(record_file); head:close() end);