Software /
code /
prosody
File
plugins/mod_http_errors.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 | 11664:d83f8f44caea |
child | 11820:0375ef78ed64 |
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module:set_global(); local server = require "net.http.server"; local codes = require "net.http.codes"; local xml_escape = require "util.stanza".xml_escape; local render = require "util.interpolation".new("%b{}", xml_escape); local show_private = module:get_option_boolean("http_errors_detailed", false); local always_serve = module:get_option_boolean("http_errors_always_show", true); local default_message = { module:get_option_string("http_errors_default_message", "That's all I know.") }; local default_messages = { [400] = { "What kind of request do you call that??" }; [403] = { "You're not allowed to do that." }; [404] = { "Whatever you were looking for is not here. %"; "Where did you put it?", "It's behind you.", "Keep looking." }; [500] = { "% Check your error log for more info."; "Gremlins.", "It broke.", "Don't look at me." }; ["/"] = { "A study in simplicity."; "Better catch it!"; "Don't just stand there, go after it!"; "Well, say something, before it runs too far!"; "Welcome to the world of XMPP!"; "You can do anything in XMPP!"; -- "The only limit is XML."; "You can do anything with Prosody!"; -- the only limit is memory? }; }; local messages = setmetatable(module:get_option("http_errors_messages", {}), { __index = default_messages }); local html = [[ <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>{title}</title> <style> body{margin-top:14%;text-align:center;background-color:#f8f8f8;font-family:sans-serif} h1{font-size:xx-large} p{font-size:x-large} p.warning>span{font-size:large;background-color:yellow} p.extra{font-size:large;font-family:courier} @media(prefers-color-scheme:dark){ body{background-color:#161616;color:#eee} p.warning>span{background-color:inherit;color:yellow} } </style> </head> <body> <h1>{icon?{icon_raw!?}} {title}</h1> <p>{message}</p> {warning&<p class="warning"><span>⚠ {warning?} ⚠</span></p>} {extra&<p class="extra">{extra?}</p>} </body> </html> ]]; local function get_page(code, extra) local message = messages[code]; if always_serve or message then message = message or default_message; return render(html, { title = rawget(codes, code) or ("Code "..tostring(code)); message = message[1]:gsub("%%", function () return message[math.random(2, math.max(#message,2))]; end); extra = extra; }); end end -- Main error page handler module:hook_object_event(server, "http-error", function (event) if event.response then event.response.headers.content_type = "text/html; charset=utf-8"; end return get_page(event.code, (show_private and event.private_message) or event.message or (event.error and event.error.text)); end); -- Way to use the template for other things so to give a consistent appearance module:hook("http-message", function (event) if event.response then event.response.headers.content_type = "text/html; charset=utf-8"; end return render(html, event); end); local icon = [[ <svg xmlns="http://www.w3.org/2000/svg" height="0.7em" viewBox="0 0 480 480" width="0.7em"> <rect fill="#6197df" height="220" rx="60" ry="60" width="220" x="10" y="10"></rect> <rect fill="#f29b00" height="220" rx="60" ry="60" width="220" x="10" y="240"></rect> <rect fill="#f29b00" height="220" rx="60" ry="60" width="220" x="240" y="10"></rect> <rect fill="#6197df" height="220" rx="60" ry="60" width="220" x="240" y="240"></rect> </svg> ]]; -- Something nicer shown instead of 404 at the root path, if nothing else handles this path module:hook_object_event(server, "http-error", function (event) local request, response = event.request, event.response; if request and response and request.path == "/" and response.status_code == 404 then response.status_code = 200; response.headers.content_type = "text/html; charset=utf-8"; local message = messages["/"]; return render(html, { icon_raw = icon, title = "Prosody is running!"; message = message[math.random(#message)]; }); end end, 1);